Programs & Examples On #Asa

Cisco ASA (Adaptive Security Appliance) is a family of security products from Cisco Systems. For Sybase ASA, use [tag:sybase-asa]

Why my regexp for hyphenated words doesn't work?

This regex should do it.


\b indicates a word-boundary.

Objects are not valid as a React child. If you meant to render a collection of children, use an array instead

I also occured the error,and I sloved it by removing the curly braces,hope it will help someone else.

You can see that ,I did not put the con in the curly brace,and the error occured ,when I remove the burly brace , the error disappeared.

const modal = (props) => {
const { show, onClose } = props;

let con = <div className="modal" onClick={onClose}>

return show === true ? (
) : (

There are an article about the usage of the curly here

error: resource android:attr/fontVariationSettings not found

I encountered this error in a flutter project and all I had to do update my compileSdkVersion to 28.


  1. In your app level build.gradle file, search for compileSdkVersion
  2. Check the current version
  3. If less than 28, update it to 28

As zyc zyc stated above, the property fontVariationSettings was added in API level 28.

You can also read more about it here

How to solve npm install throwing fsevents warning on non-MAC OS?

Yes, it works when with the command npm install --no-optional
Using environment:

  • iTerm2
  • macos login to my vm ubuntu16 LTS.

How to install/start Postman native v4.10.3 on Ubuntu 16.04 LTS 64-bit?

don't forget to

chmod ~/.local/share/applications/postman.desktop +x

otherwise it won't show in the Unity Launcher

Powershell Invoke-WebRequest Fails with SSL/TLS Secure Channel

If, like me, none of the above quite works, it might be worth also specifically trying a lower TLS version alone. I had tried both of the following, but didn't seem to solve my problem:

[Net.ServicePointManager]::SecurityProtocol = "tls12, tls11, tls"
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 -bor [Net.SecurityProtocolType]::Tls11 -bor [Net.SecurityProtocolType]::Tls

In the end, it was only when I targetted TLS 1.0 (specifically remove 1.1 and 1.2 in the code) that it worked:

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls

The local server (that this was being attempted on) is fine with TLS 1.2, although the remote server (which was previously "confirmed" as fine for TLS 1.2 by a 3rd party) seems not to be.

Hope this helps someone.

Importing class from another file

Your problem is basically that you never specified the right path to the file.

Try instead, from your main script:

from folder.file import Klasa

Or, with from folder import file:

from folder import file
k = file.Klasa()

Or again:

import folder.file as myModule
k = myModule.Klasa()

Get all validation errors from Angular 2 FormGroup

export class GenericValidator {
    constructor(private validationMessages: { [key: string]: { [key: string]: string } }) {

processMessages(container: FormGroup): { [key: string]: string } {
    const messages = {};
    for (const controlKey in container.controls) {
        if (container.controls.hasOwnProperty(controlKey)) {
            const c = container.controls[controlKey];
            if (c instanceof FormGroup) {
                const childMessages = this.processMessages(c);
                // handling formGroup errors messages
                const formGroupErrors = {};
                if (this.validationMessages[controlKey]) {
                    formGroupErrors[controlKey] = '';
                    if (c.errors) {
                        Object.keys(c.errors).map((messageKey) => {
                            if (this.validationMessages[controlKey][messageKey]) {
                                formGroupErrors[controlKey] += this.validationMessages[controlKey][messageKey] + ' ';
                Object.assign(messages, childMessages, formGroupErrors);
            } else {
                // handling control fields errors messages
                if (this.validationMessages[controlKey]) {
                    messages[controlKey] = '';
                    if ((c.dirty || c.touched) && c.errors) {
                        Object.keys(c.errors).map((messageKey) => {
                            if (this.validationMessages[controlKey][messageKey]) {
                                messages[controlKey] += this.validationMessages[controlKey][messageKey] + ' ';
    return messages;

I took it from Deborahk and modified it a little bit.

Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?

You did not post the code generated by the compiler, so there' some guesswork here, but even without having seen it, one can say that this:

test rax, 1
jpe even

... has a 50% chance of mispredicting the branch, and that will come expensive.

The compiler almost certainly does both computations (which costs neglegibly more since the div/mod is quite long latency, so the multiply-add is "free") and follows up with a CMOV. Which, of course, has a zero percent chance of being mispredicted.

Showing ValueError: shapes (1,3) and (1,3) not aligned: 3 (dim 1) != 1 (dim 0), b, out=None)

Dot product of two arrays.

For N dimensions it is a sum product over the last axis of a and the second-to-last of b.


How to unpack an .asar file?

UI for Asar, Extract All, or drag extract file/directory

Normalizing images in OpenCV

The other answers normalize an image based on the entire image. But if your image has a predominant color (such as black), it will mask out the features that you're trying to enhance since it will not be as pronounced. To get around this limitation, we can normalize the image based on a subsection region of interest (ROI). Essentially we will normalize based on the section of the image that we want to enhance instead of equally treating each pixel with the same weight. Take for instance this earth image:

Input image -> Normalization based on entire image

If we want to enhance the clouds by normalizing based on the entire image, the result will not be very sharp and will be over saturated due to the black background. The features to enhance are lost. So to obtain a better result we can crop a ROI, normalize based on the ROI, and then apply the normalization back onto the original image. Say we crop the ROI highlighted in green:

This gives us this ROI

The idea is to calculate the mean and standard deviation of the ROI and then clip the frame based on the lower and upper range. In addition, we could use an offset to dynamically adjust the clip intensity. From here we normalize the original image to this new range. Here's the result:

Before -> After


import cv2
import numpy as np

# Load image as grayscale and crop ROI
image = cv2.imread('1.png', 0)
x, y, w, h = 364, 633, 791, 273
ROI = image[y:y+h, x:x+w]

# Calculate mean and STD
mean, STD  = cv2.meanStdDev(ROI)

# Clip frame to lower and upper STD
offset = 0.2
clipped = np.clip(image, mean - offset*STD, mean + offset*STD).astype(np.uint8)

# Normalize to range
result = cv2.normalize(clipped, clipped, 0, 255, norm_type=cv2.NORM_MINMAX)

cv2.imshow('image', image)
cv2.imshow('ROI', ROI)
cv2.imshow('result', result)

The difference between normalizing based on the entire image vs a specific section of the ROI can be visualized by applying a heatmap to the result. Notice the difference on how the clouds are defined.

Input image -> heatmap

Normalized on entire image -> heatmap

Normalized on ROI -> heatmap

Heatmap code

import matplotlib.pyplot as plt
import numpy as np
import cv2

image = cv2.imread('result.png', 0)
colormap = plt.get_cmap('inferno')
heatmap = (colormap(image) * 2**16).astype(np.uint16)[:,:,:3]
heatmap = cv2.cvtColor(heatmap, cv2.COLOR_RGB2BGR)

cv2.imshow('image', image)
cv2.imshow('heatmap', heatmap)

Note: The ROI bounding box coordinates were obtained using how to get ROI Bounding Box Coordinates without Guess & Check and heatmap code was from how to convert a grayscale image to heatmap image with Python OpenCV

Iterating over Typescript Map

Just a simple explanation to use it in an HTML document.

If you have a Map of types (key, array) then you initialise the array this way:

public cityShop: Map<string, Shop[]> = new Map();

And to iterate over it, you create an array from key values.

Just use it as an array as in:

keys = Array.from(this.cityShop.keys());

Then, in HTML, you can use:

*ngFor="let key of keys"

Inside this loop, you just get the array value with:



#1292 - Incorrect date value: '0000-00-00'

You have 3 options to make your way:
1. Define a date value like '1970-01-01'
2. Select NULL from the dropdown to keep it blank.
3. Select CURRENT_TIMESTAMP to set current datetime as default value.

docker unauthorized: authentication required - upon push with successful login

I have received similar error for sudo docker push /sudo docker pull on ecr repository.This is because aws cli installed in my user(abc) and docker installed in root user.I have tried to run sudo docker push on my user(abc)

Fixed this by installed aws cli in root , configured aws using aws configure in root and run sudo docker push to ecr on root user

Install pip in docker

This command worked fine for me:

RUN apt-get -y install python3-pip

How to convert an Image to base64 string in java?

The problem is that you are returning the toString() of the call to Base64.encodeBase64(bytes) which returns a byte array. So what you get in the end is the default string representation of a byte array, which corresponds to the output you get.

Instead, you should do:

encodedfile = new String(Base64.encodeBase64(bytes), "UTF-8");

How to extend / inherit components?

Alternative Solution:

This answer of Thierry Templier is an alternative way to get around the problem.

After some questions with Thierry Templier, I came to the following working example that meets my expectations as an alternative to inheritance limitation mentioned in this question:

1 - Create custom decorator:

export function CustomComponent(annotation: any) {
  return function (target: Function) {
    var parentTarget = Object.getPrototypeOf(target.prototype).constructor;
    var parentAnnotations = Reflect.getMetadata('annotations', parentTarget);

    var parentAnnotation = parentAnnotations[0];
    Object.keys(parentAnnotation).forEach(key => {
      if (isPresent(parentAnnotation[key])) {
        // verify is annotation typeof function
        if(typeof annotation[key] === 'function'){
          annotation[key] = annotation[key].call(this, parentAnnotation[key]);
        }else if(
        // force override in annotation base
          annotation[key] = parentAnnotation[key];

    var metadata = new Component(annotation);

    Reflect.defineMetadata('annotations', [ metadata ], target);

2 - Base Component with @Component decorator:

  // create seletor base for test override property
  selector: 'master',
  template: `
export class AbstractComponent {


3 - Sub component with @CustomComponent decorator:

  // override property annotation
  //selector: 'sub',
  selector: (parentSelector) => { return parentSelector + 'sub'}
export class SubComponent extends AbstractComponent {
  constructor() {

Plunkr with complete example.

TypeScript for ... of with index / key?

.forEach already has this ability:

const someArray = [9, 2, 5];
someArray.forEach((value, index) => {
    console.log(index); // 0, 1, 2
    console.log(value); // 9, 2, 5

But if you want the abilities of for...of, then you can map the array to the index and value:

for (const { index, value } of, index) => ({ index, value }))) {
    console.log(index); // 0, 1, 2
    console.log(value); // 9, 2, 5

That's a little long, so it may help to put it in a reusable function:

function toEntries<T>(a: T[]) {
    return, index) => [index, value] as const);

for (const [index, value] of toEntries(someArray)) {
    // ..etc..

Iterable Version

This will work when targeting ES3 or ES5 if you compile with the --downlevelIteration compiler option.

function* toEntries<T>(values: T[] | IterableIterator<T>) {
    let index = 0;
    for (const value of values) {
        yield [index, value] as const;

Array.prototype.entries() - ES6+

If you are able to target ES6+ environments then you can use the .entries() method as outlined in Arnavion's answer.

java.time.format.DateTimeParseException: Text could not be parsed at index 21

The default parser can parse your input. So you don't need a custom formatter and

String dateTime = "2012-02-22T02:06:58.147Z";
ZonedDateTime d = ZonedDateTime.parse(dateTime);

works as expected.

How to set menu to Toolbar in Android

In your activity override this method.

    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(, menu);
        return true;

This will inflate your menu below:

 <?xml version="1.0" encoding="utf-8"?>
    <menu xmlns:android=""

            android:title="Setting" />

            android:title="Setting" />


TypeError: ufunc 'add' did not contain a loop with signature matching types

You have a numpy array of strings, not floats. This is what is meant by dtype('<U9') -- a little endian encoded unicode string with up to 9 characters.


return sum(np.asarray(listOfEmb, dtype=float)) / float(len(listOfEmb))

However, you don't need numpy here at all. You can really just do:

return sum(float(embedding) for embedding in listOfEmb) / len(listOfEmb)

Or if you're really set on using numpy.

return np.asarray(listOfEmb, dtype=float).mean()

Error reading JObject from JsonReader. Current JsonReader item is not an object: StartArray. Path

The first part of your question is a duplicate of Why do I get a JsonReaderException with this code?, but the most relevant part from that (my) answer is this:

[A] JObject isn't the elementary base type of everything in, but JToken is. So even though you could say,

object i = new int[0];

in C#, you can't say,

JObject i = JObject.Parse("[0, 0, 0]");


What you want is JArray.Parse, which will accept the array you're passing it (denoted by the opening [ in your API response). This is what the "StartArray" in the error message is telling you.

As for what happened when you used JArray, you're using arr instead of obj:

var rcvdData = JsonConvert.DeserializeObject<LocationData>(arr /* <-- Here */.ToString(), settings);

Swap that, and I believe it should work.

Although I'd be tempted to deserialize arr directly as an IEnumerable<LocationData>, which would save some code and effort of looping through the array. If you aren't going to use the parsed version separately, it's best to avoid it.

Angular 2 router no base href set

I had faced similar issue with Angular4 and Jasmine unit tests; below given solution worked for me

Add below import statement

import { APP_BASE_HREF } from '@angular/common';

Add below statement for TestBed configuration:

    providers: [
        { provide: APP_BASE_HREF, useValue : '/' }

npm install -g less does not work: EACCES: permission denied

For my mac environment

sudo chown -R $USER /usr/local/lib/node_modules

solve the issue

Convert list or numpy array of single element to float in python

Just access the first item of the list/array, using the index access and the index 0:

>>> list_ = [4]
>>> list_[0]
>>> array_ = np.array([4])
>>> array_[0]

This will be an int since that was what you inserted in the first place. If you need it to be a float for some reason, you can call float() on it then:

>>> float(list_[0])

How to convert a DataFrame back to normal RDD in pyspark?

@dapangmao's answer works, but it doesn't give the regular spark RDD, it returns a Row object. If you want to have the regular RDD format.

Try this:

rdd =


rdd =

EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType

In my case I had inherited from the IdentityDbContext correctly (with my own custom types and key defined) but had inadvertantly removed the call to the base class's OnModelCreating:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
    base.OnModelCreating(modelBuilder); // I had removed this
    /// Rest of on model creating here.

Which then fixed up my missing indexes from the identity classes and I could then generate migrations and enable migrations appropriately.

How to set up a Web API controller for multipart/form-data

5 years later on and .NET Core 3.1 allows you to do specify the media type like this:

public IActionResult UploadLogo()
    return Ok();

Spring Maven clean error - The requested profile "pom.xml" could not be activated because it does not exist

Goto Properties -> maven Remove the pom.xml from the activate profiles and follow the below steps.

Steps :

  1. Delete the .m2 repository
  2. Restart the Eclipse IDE
  3. Refresh and Rebuild it

Check if an element has event listener on it. No jQuery

Nowadays (2016) in Chrome Dev Tools console, you can quickly execute this function below to show all event listeners that have been attached to an element.


Creating a SearchView that looks like the material design guidelines

It is actually quite easy to do this, if you are using library.

Step - 1

Declare a menu item

<item android:id="@+id/action_search"
    app:actionViewClass="" />

Step - 2

Extend AppCompatActivity and in the onCreateOptionsMenu setup the SearchView.



public class YourActivity extends AppCompatActivity {


    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(, menu);
        // Retrieve the SearchView and plug it into SearchManager
        final SearchView searchView = (SearchView) MenuItemCompat.getActionView(menu.findItem(;
        SearchManager searchManager = (SearchManager) getSystemService(SEARCH_SERVICE);
        return true;




enter image description here

enter image description here

Converting list to numpy array

If you have a list of lists, you only needed to use ...

import numpy as np
npa = np.asarray(someListOfLists, dtype=np.float32)

per this LINK in the scipy / numpy documentation. You just needed to define dtype inside the call to asarray.

How to add buttons like refresh and search in ToolBar in Android?

Add this line at the top:


and then use:


How to auto adjust the div size for all mobile / tablet display formats?

You can use the viewport height, just set the height of your div to height:100vh;, this will set the height of your div to the height of the viewport of the device, furthermore, if you want it to be exactly as your device screen, set the margin and padding to 0.

Plus, It will be a good idea to set the viewport meta tag:

<meta name="viewport" content="width=device-width,height=device-height,initial-scale=1.0" />

Please Note that this is relatively new and is not supported in IE8-, take a look at the support list before considering this approach (

Hope this helps.

Why is it that "No HTTP resource was found that matches the request URI" here?

Please check the class you inherited. Whether it is simply Controller or APIController.

By mistake we might create a controller from MVC 5 controller. It should be from Web API Controller.

Deserialize JSON to Array or List with HTTPClient .ReadAsAsync using .NET 4.0 Task pattern

var response = taskwithresponse.Result;
          var jsonString = response.ReadAsAsync<List<Job>>().Result;

IIs Error: Application Codebehind=“Global.asax.cs” Inherits=“nadeem.MvcApplication”

Solved, just renamed the Global.asax or delete it fixed the problem :/

Other known related bugs I found on the web:

  1. Global.asax.cs: must inherit from HttpApplication -> public class MvcApplication : HttpApplication
  2. Project output must be the bin folder and not Bin/Debug, etc.
  3. Iss application pool is not in the correct .net version.

How to disable SSL certificate checking with Spring RestTemplate?

For the sake of other developers who finds this question and need another solution that fits not only for unit-tests:

I've found this on a blog (not my solution! Credit to the blog's owner).

TrustStrategy acceptingTrustStrategy = (X509Certificate[] chain, String authType) -> true;

SSLContext sslContext = org.apache.http.ssl.SSLContexts.custom()
        .loadTrustMaterial(null, acceptingTrustStrategy)

SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext);

CloseableHttpClient httpClient = HttpClients.custom()

HttpComponentsClientHttpRequestFactory requestFactory =
        new HttpComponentsClientHttpRequestFactory();


RestTemplate restTemplate = new RestTemplate(requestFactory);

Start redis-server with config file

Okay, redis is pretty user friendly but there are some gotchas.

Here are just some easy commands for working with redis on Ubuntu:


sudo apt-get install redis-server

start with conf:

sudo redis-server <path to conf>
sudo redis-server config/redis.conf

stop with conf:

redis-ctl shutdown

(not sure how this shuts down the pid specified in the conf. Redis must save the path to the pid somewhere on boot)


tail -f /var/log/redis/redis-server.log

Also, various example confs floating around online and on this site were beyond useless. The best, sure fire way to get a compatible conf is to copy-paste the one your installation is already using. You should be able to find it here:


Then paste it at <path to conf>, tweak as needed and you're good to go.

Bootstrap 3 truncate long text inside rows of a table in a responsive way

This is what I achieved, but had to set width, and it cannot be percentual.

  width:250px; _x000D_
  white-space: nowrap; _x000D_
  overflow: hidden; _x000D_
  text-overflow: ellipsis;_x000D_
table tr td {_x000D_
padding: 5px_x000D_
table tr td {_x000D_
background: salmon_x000D_
table tr td:first-child {_x000D_
background: lightsalmon_x000D_
<link href="" rel="stylesheet"/>_x000D_
<script src=""></script>_x000D_
        <td>Quisque dignissim ante in tincidunt gravida. Maecenas lectus turpis</td>_x000D_
         <div class="trunc">Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum._x000D_

or this:

Error sending json in POST to web API service

It require to include Content-Type:application/json in web api request header section when not mention any content then by default it is Content-Type:text/plain passes to request.

Best way to test api on postman tool.

json: cannot unmarshal object into Go value of type

You JSON doesn't match your struct fields: E.g. "district" in JSON and "District" as the field.

Also: Your Item is a slice type but your JSON is a dict value. Do not mix this up. Slices decode from arrays.

Implementing SearchView in action bar

SearchDialog or SearchWidget ?

When it comes to implement a search functionality there are two suggested approach by official Android Developer Documentation.
You can either use a SearchDialog or a SearchWidget.
I am going to explain the implementation of Search functionality using SearchWidget.

How to do it with Search widget ?

I will explain search functionality in a RecyclerView using SearchWidget. It's pretty straightforward.

Just follow these 5 Simple steps

1) Add searchView item in the menu

You can add SearchView can be added as actionView in menu using

app:useActionClass = "" .

<menu xmlns:android=""

2) Set up SerchView Hint text, listener etc

You should initialize SearchView in the onCreateOptionsMenu(Menu menu) method.

  public boolean onCreateOptionsMenu(Menu menu) {
     // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(, menu);

        MenuItem searchItem = menu.findItem(;

        SearchView searchView = (SearchView) searchItem.getActionView();
        searchView.setQueryHint("Search People");

        return true;

3) Implement SearchView.OnQueryTextListener in your Activity

OnQueryTextListener has two abstract methods

  1. onQueryTextSubmit(String query)
  2. onQueryTextChange(String newText

So your Activity skeleton would look like this

YourActivity extends AppCompatActivity implements SearchView.OnQueryTextListener{

     public boolean onQueryTextSubmit(String query)

     public boolean onQueryTextChange(String newText) 


4) Implement SearchView.OnQueryTextListener

You can provide the implementation for the abstract methods like this

public boolean onQueryTextSubmit(String query) {

    // This method can be used when a query is submitted eg. creating search history using SQLite DB

    Toast.makeText(this, "Query Inserted", Toast.LENGTH_SHORT).show();
    return true;

public boolean onQueryTextChange(String newText) {

    return true;

5) Write a filter method in your RecyclerView Adapter.

Most important part. You can write your own logic to perform search.
Here is mine. This snippet shows the list of Name which contains the text typed in the SearchView

public void filter(String queryText)


       for(String name: copyList)



Relevant link:

Full working code on SearchView with an SQLite database in this Music App

data.table vs dplyr: can one do something well the other can't or does poorly?

In direct response to the Question Title...

dplyr definitely does things that data.table can not.

Your point #3

dplyr abstracts (or will) potential DB interactions

is a direct answer to your own question but isn't elevated to a high enough level. dplyr is truly an extendable front-end to multiple data storage mechanisms where as data.table is an extension to a single one.

Look at dplyr as a back-end agnostic interface, with all of the targets using the same grammer, where you can extend the targets and handlers at will. data.table is, from the dplyr perspective, one of those targets.

You will never (I hope) see a day that data.table attempts to translate your queries to create SQL statements that operate with on-disk or networked data stores.

dplyr can possibly do things data.table will not or might not do as well.

Based on the design of working in-memory, data.table could have a much more difficult time extending itself into parallel processing of queries than dplyr.

In response to the in-body questions...


Are there analytical tasks that are a lot easier to code with one or the other package for people familiar with the packages (i.e. some combination of keystrokes required vs. required level of esotericism, where less of each is a good thing).

This may seem like a punt but the real answer is no. People familiar with tools seem to use the either the one most familiar to them or the one that is actually the right one for the job at hand. With that being said, sometimes you want to present a particular readability, sometimes a level of performance, and when you have need for a high enough level of both you may just need another tool to go along with what you already have to make clearer abstractions.


Are there analytical tasks that are performed substantially (i.e. more than 2x) more efficiently in one package vs. another.

Again, no. data.table excels at being efficient in everything it does where dplyr gets the burden of being limited in some respects to the underlying data store and registered handlers.

This means when you run into a performance issue with data.table you can be pretty sure it is in your query function and if it is actually a bottleneck with data.table then you've won yourself the joy of filing a report. This is also true when dplyr is using data.table as the back-end; you may see some overhead from dplyr but odds are it is your query.

When dplyr has performance issues with back-ends you can get around them by registering a function for hybrid evaluation or (in the case of databases) manipulating the generated query prior to execution.

Also see the accepted answer to when is plyr better than data.table?

What is a 'NoneType' object?

In Python, to represent the absence of a value, you can use the None value types.NoneType.None

Python+OpenCV: cv2.imwrite

This following code should extract face in images and save faces on disk

def detect(image):
    image_faces = []
    bitmap = cv.fromarray(image)
    faces = cv.HaarDetectObjects(bitmap, cascade, cv.CreateMemStorage(0))
    if faces:
        for (x,y,w,h),n in faces:
            image_faces.append(image[y:(y+h), x:(x+w)])
    return image_faces

if __name__ == "__main__":
    cam = cv2.VideoCapture(0)
    while 1:
        image_faces = []
        image_faces = detect(frame)
        for i, face in enumerate(image_faces):
            cv2.imwrite("face-" + str(i) + ".jpg", face)

        #cv2.imshow("features", frame)
        if cv2.waitKey(1) == 0x1b: # ESC
            print 'ESC pressed. Exiting ...'

GlobalConfiguration.Configure() not present after Web API 2 and .NET 4.5.1 migration

GlobalConfiguration.Configure API is available in "Microsoft.AspNet.WebApi.WebHost" version="5.2.3"

and not in "Microsoft.AspNet.WebApi.WebHost" version="4.0.0"

EntityType has no key defined error

  1. Make sure public members of student class are defined as properties w/ {get; set;} (yours are public variables - a common mistake).

  2. Place a [Key] annotation on top of your chosen property.

Display JSON Data in HTML Table

 <div id="container"></div>   

$('#search').click(function() {
        type: 'POST',
        url: 'cityResults.htm',
        data: $('#cityDetails').serialize(),
        dataType:"json", //to parse string into JSON object,
        success: function(data){ 

                var len = data.length;
                var txt = "";
                if(len > 0){
                    for(var i=0;i<len;i++){

                            txt = "<tr><td>"+data[i].city+"</td><td>"+data[i].cStatus+"</td></tr>";

        error: function(jqXHR, textStatus, errorThrown){
            alert('error: ' + textStatus + ': ' + errorThrown);
    return false;

how to create a logfile in php?

create a logfile in php, to do it you need to pass data on function and it will create log file for you.

function wh_log($log_msg)
    $log_filename = "log";
    if (!file_exists($log_filename)) 
        // create directory/folder uploads.
        mkdir($log_filename, 0777, true);
    $log_file_data = $log_filename.'/log_' . date('d-M-Y') . '.log';
    // if you don't add `FILE_APPEND`, the file will be erased each time you add a log
    file_put_contents($log_file_data, $log_msg . "\n", FILE_APPEND);
// call to function
wh_log("this is my log message");

How to change MenuItem icon in ActionBar programmatically

Instead of getViewById(), use

MenuItem item = getToolbar().getMenu().findItem(Menu.FIRST);

replacing the Menu.FIRST with your menu item id.

Attempt to set a non-property-list object as an NSUserDefaults

Swift- 4 Xcode 9.1

try this code

you can not store mapper in NSUserDefault, you can only store NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary.

let myData = NSKeyedArchiver.archivedData(withRootObject: myJson)
UserDefaults.standard.set(myData, forKey: "userJson")

let recovedUserJsonData = UserDefaults.standard.object(forKey: "userJson")
let recovedUserJson = NSKeyedUnarchiver.unarchiveObject(with: recovedUserJsonData)

How to run python script with elevated privilege on windows

in comments to the answer you took the code from someone says ShellExecuteEx doesn't post its STDOUT back to the originating shell. so you will not see "I am root now", even though the code is probably working fine.

instead of printing something, try writing to a file:

import os
import sys
import as shell
ASADMIN = 'asadmin'

if sys.argv[-1] != ASADMIN:
    script = os.path.abspath(sys.argv[0])
    params = ' '.join([script] + sys.argv[1:] + [ASADMIN])
    shell.ShellExecuteEx(lpVerb='runas', lpFile=sys.executable, lpParameters=params)
with open("somefilename.txt", "w") as out:
    print >> out, "i am root"

and then look in the file.

How to change the background color of Action Bar's Option Menu in Android 4.2?

My simple trick to change background color and color of the text in Popup Menu / Option Menu

<style name="CustomActionBarTheme"
    <item name="android:popupMenuStyle">@style/MyPopupMenu</item>
    <item name="android:itemTextAppearance">@style/TextAppearance</item>
<!-- Popup Menu Background Color styles -->
<style name="MyPopupMenu" 
    <item name="android:popupBackground">@color/Your_color_for_background</item> 
<!-- Popup Menu Text Color styles -->
<style name="TextAppearance">
    <item name="android:textColor">@color/Your_color_for_text</item>

HTTP Error 503. The service is unavailable. App pool stops on accessing website

When I first time add the service and created the app pool for it. I did "iisreset" from command prompt, and it worked.

Unsuccessful append to an empty NumPy array

This error arise from the fact that you are trying to define an object of shape (0,) as an object of shape (2,). If you append what you want without forcing it to be equal to result[0] there is no any issue:

b = np.append([result[0]], [1,2])

But when you define result[0] = b you are equating objects of different shapes, and you can not do this. What are you trying to do?

python: changing row index of pandas data frame

you can do

followers_df.index = range(20)

Could not load file or assembly 'System.Web.Http 4.0.0 after update from 2012 to 2013

ASP.NET Version:4.0.30319.18408 belongs to .Net4.5 and System.Web.Http Version= is compatible for .NET4.0. So the versions that you have are not compatible. You should update you System.Web.Http to version, which is compatible with .Net4.5

ASP.NET MVC5/IIS Express unable to debug - Code Not Running

The following steps fix the problem for VS 2015 and VS 2017:

Close VS.

Navigate to the folder of the solution and delete the hidden .vs folder.

open VS.

Hit F5 and IIS Express should load as normal, allowing you to debug.

How to convert an array into an object using stdClass()

or you can use this thing

$arr = [1,2,3];
$obj = json_decode(json_encode($arr));

Web API Put Request generates an Http 405 Method Not Allowed error

Decorating one of the action params with [FromBody] solved the issue for me:

public async Task<IHttpActionResult> SetAmountOnEntry(string id, [FromBody]int amount)

However ASP.NET would infer it correctly if complex object was used in the method parameter:

public async Task<IHttpActionResult> UpdateEntry(string id, MyEntry entry)

Logging request/response messages when using HttpClient

The easiest solution would be to use Wireshark and trace the HTTP tcp flow.

Making an iframe responsive

check out this solution... works for me >>

<html lang="en" class="no-js">
      <meta charset="utf-8">
      <meta name="viewport" content="width=device-width,initial-scale=1.0">
      html body {width: 100%;height: 100%;padding: 0px;margin: 0px;overflow: hidden;font-family: arial;font-size: 10px;color: #6e6e6e;background-color: #000;} #preview-frame {width: 100%;background-color: #fff;}</style>
      <script src="//"></script>
         var calcHeight = function() {

         $(document).ready(function() {

         $(window).resize(function() {
         }).load(function() {
      <iframe id="preview-frame" src="" name="preview-frame" frameborder="0" noresize="noresize">

Are nested try/except blocks in Python a good programming practice?

A good and simple example for nested try/except could be the following:

import numpy as np

def divide(x, y):
        out = x/y
            out = np.inf * x / abs(x)
            out = np.nan
        return out

Now try various combinations and you will get the correct result:

divide(15, 3)
# 5.0

divide(15, 0)
# inf

divide(-15, 0)
# -inf

divide(0, 0)
# nan

(Of course, we have NumPy, so we don't need to create this function.)

Deserialize a JSON array in C#

This code is working fine for me,

var a = serializer.Deserialize<List<Entity>>(json);

Excel VBA Code: Compile Error in x64 Version ('PtrSafe' attribute required)

I think all you need to do for your function is just add PtrSafe: i.e. the first line of your first function should look like this:

Private Declare PtrSafe Function swe_azalt Lib "swedll32.dll" ......

python 3.2 UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 9629: character maps to <undefined>

When you open the file you want to write to, open it with a specific encoding that can handle all the characters.

with open('filename', 'w', encoding='utf-8') as f:
    print(r['body'], file=f)

How can I bold the fonts of a specific row or cell in an Excel worksheet with C#?

How to Bold entire row 10 example:

workSheet.Cells[10, 1].EntireRow.Font.Bold = true;    

More formally:

Microsoft.Office.Interop.Excel.Range rng = workSheet.Cells[10, 1] as Xl.Range;
rng.EntireRow.Font.Bold = true;

How to Bold Specific Cell 'A10' for example:

workSheet.Cells[10, 1].Font.Bold = true;

Little more formal:

int row = 1;
int column = 1;  /// 1 = 'A' in Excel

Microsoft.Office.Interop.Excel.Range rng = workSheet.Cells[row, column] as Xl.Range;
rng.Font.Bold = true;

Java double.MAX_VALUE?

Double.MAX_VALUE is the maximum value a double can represent (somewhere around 1.7*10^308).

This should end in some calculation problems, if you try to subtract the maximum possible value of a data type.

Even though when you are dealing with money you should never use floating point values especially while rounding this can cause problems (you will either have to much or less money in your system then).

Maven is not working in Java 8 when Javadoc tags are incomplete

I don't think just turning off DocLint is a good solution, at least not long term. It is good that Javadoc has become a bit more strict so the right way to fix the build problem is to fix the underlying problem. Yes, you'll ultimately need to fix those source code files.

Here are the things to look out for that you could previously get away with:

  • Malformed HTML (for example a missing end-tag, un-escaped brackets, etc)
  • Invalid {@link }s. (same goes for similar tags such as @see)
  • Invalid @author values. This used to be accepted : @author John <[email protected]> but not so anymore because of the un-escaped brackets.
  • HTML tables in Javadoc now require a summary or caption. See this question for explanation.

You'll simply have to fix your source code files and keep building your Javadoc until it can build without a failure. Cumbersome yes, but personally I like when I have brought my projects up to DocLint level because it means I can be more confident that the Javadoc I produce is actually what I intend.

There's of course the problem if you are generating Javadoc on some source code you've not produced yourself, for example because it comes from some code generator, e.g. wsimport. Strange that Oracle didn't prepare their own tools for JDK8 compliance before actually releasing JDK8. It seems it won't be fixed until Java 9. Only in this particular case I suggest to turn off DocLint as documented elsewhere on this page.

How to save a bitmap on internal storage

Modify onClick() as follows:

public void onClick(View v) {
    if(v == btn) {
        if(canvas!=null) {
            canvas.drawBitmap(bitmap, 100, 100, null);
    } else if(v == btn1) {

There are several ways to enforce that btn must be pressed before btn1 so that the bitmap is painted before you attempt to save it.

I suggest that you initially disable btn1, and that you enable it when btn is clicked, like this:

if(v == btn) {
} Button OnClick event not firing

Try to go into Design mode in Visual Studio, locate the button and double click the button that should setup the event. Otherwise once the button is selected in Design more, go to the properties and try setting it from there.

All ASP.NET Web API controllers return 404

Create a Route attribute for your method.


        public IEnumerable<string> Get()
            return new string[] { "value1", "value2" };

You can call like these http://localhost/api/Get

jQuery click events not working in iOS

Recently when working on a web app for a client, I noticed that any click events added to a non-anchor element didn't work on the iPad or iPhone. All desktop and other mobile devices worked fine - but as the Apple products are the most popular mobile devices, it was important to get it fixed.

Turns out that any non-anchor element assigned a click handler in jQuery must either have an onClick attribute (can be empty like below):



The element css needs to have the following declaration:


Strange, but that's what it took to get things working again!

How to generate an MD5 file hash in JavaScript?

You could use crypto-js.

I would also recommend using SHA256, rather than MD5.

To install crypto-js via NPM:

npm install crypto-js

Alternatively you can use a CDN and reference the JS file.

Then to display a MD5 and SHA256 hash, you can do the following:

<script type="text/javascript">
    var md5Hash = CryptoJS.MD5("Test");
    var sha256Hash = CryptoJS.SHA256("Test1");


Working example located here, JSFiddle

There are also other JS functions that will generate an MD5 hash, outlined below.

function md5cycle(x, k) {
var a = x[0], b = x[1], c = x[2], d = x[3];

a = ff(a, b, c, d, k[0], 7, -680876936);
d = ff(d, a, b, c, k[1], 12, -389564586);
c = ff(c, d, a, b, k[2], 17,  606105819);
b = ff(b, c, d, a, k[3], 22, -1044525330);
a = ff(a, b, c, d, k[4], 7, -176418897);
d = ff(d, a, b, c, k[5], 12,  1200080426);
c = ff(c, d, a, b, k[6], 17, -1473231341);
b = ff(b, c, d, a, k[7], 22, -45705983);
a = ff(a, b, c, d, k[8], 7,  1770035416);
d = ff(d, a, b, c, k[9], 12, -1958414417);
c = ff(c, d, a, b, k[10], 17, -42063);
b = ff(b, c, d, a, k[11], 22, -1990404162);
a = ff(a, b, c, d, k[12], 7,  1804603682);
d = ff(d, a, b, c, k[13], 12, -40341101);
c = ff(c, d, a, b, k[14], 17, -1502002290);
b = ff(b, c, d, a, k[15], 22,  1236535329);

a = gg(a, b, c, d, k[1], 5, -165796510);
d = gg(d, a, b, c, k[6], 9, -1069501632);
c = gg(c, d, a, b, k[11], 14,  643717713);
b = gg(b, c, d, a, k[0], 20, -373897302);
a = gg(a, b, c, d, k[5], 5, -701558691);
d = gg(d, a, b, c, k[10], 9,  38016083);
c = gg(c, d, a, b, k[15], 14, -660478335);
b = gg(b, c, d, a, k[4], 20, -405537848);
a = gg(a, b, c, d, k[9], 5,  568446438);
d = gg(d, a, b, c, k[14], 9, -1019803690);
c = gg(c, d, a, b, k[3], 14, -187363961);
b = gg(b, c, d, a, k[8], 20,  1163531501);
a = gg(a, b, c, d, k[13], 5, -1444681467);
d = gg(d, a, b, c, k[2], 9, -51403784);
c = gg(c, d, a, b, k[7], 14,  1735328473);
b = gg(b, c, d, a, k[12], 20, -1926607734);

a = hh(a, b, c, d, k[5], 4, -378558);
d = hh(d, a, b, c, k[8], 11, -2022574463);
c = hh(c, d, a, b, k[11], 16,  1839030562);
b = hh(b, c, d, a, k[14], 23, -35309556);
a = hh(a, b, c, d, k[1], 4, -1530992060);
d = hh(d, a, b, c, k[4], 11,  1272893353);
c = hh(c, d, a, b, k[7], 16, -155497632);
b = hh(b, c, d, a, k[10], 23, -1094730640);
a = hh(a, b, c, d, k[13], 4,  681279174);
d = hh(d, a, b, c, k[0], 11, -358537222);
c = hh(c, d, a, b, k[3], 16, -722521979);
b = hh(b, c, d, a, k[6], 23,  76029189);
a = hh(a, b, c, d, k[9], 4, -640364487);
d = hh(d, a, b, c, k[12], 11, -421815835);
c = hh(c, d, a, b, k[15], 16,  530742520);
b = hh(b, c, d, a, k[2], 23, -995338651);

a = ii(a, b, c, d, k[0], 6, -198630844);
d = ii(d, a, b, c, k[7], 10,  1126891415);
c = ii(c, d, a, b, k[14], 15, -1416354905);
b = ii(b, c, d, a, k[5], 21, -57434055);
a = ii(a, b, c, d, k[12], 6,  1700485571);
d = ii(d, a, b, c, k[3], 10, -1894986606);
c = ii(c, d, a, b, k[10], 15, -1051523);
b = ii(b, c, d, a, k[1], 21, -2054922799);
a = ii(a, b, c, d, k[8], 6,  1873313359);
d = ii(d, a, b, c, k[15], 10, -30611744);
c = ii(c, d, a, b, k[6], 15, -1560198380);
b = ii(b, c, d, a, k[13], 21,  1309151649);
a = ii(a, b, c, d, k[4], 6, -145523070);
d = ii(d, a, b, c, k[11], 10, -1120210379);
c = ii(c, d, a, b, k[2], 15,  718787259);
b = ii(b, c, d, a, k[9], 21, -343485551);

x[0] = add32(a, x[0]);
x[1] = add32(b, x[1]);
x[2] = add32(c, x[2]);
x[3] = add32(d, x[3]);


function cmn(q, a, b, x, s, t) {
a = add32(add32(a, q), add32(x, t));
return add32((a << s) | (a >>> (32 - s)), b);

function ff(a, b, c, d, x, s, t) {
return cmn((b & c) | ((~b) & d), a, b, x, s, t);

function gg(a, b, c, d, x, s, t) {
return cmn((b & d) | (c & (~d)), a, b, x, s, t);

function hh(a, b, c, d, x, s, t) {
return cmn(b ^ c ^ d, a, b, x, s, t);

function ii(a, b, c, d, x, s, t) {
return cmn(c ^ (b | (~d)), a, b, x, s, t);

function md51(s) {
txt = '';
var n = s.length,
state = [1732584193, -271733879, -1732584194, 271733878], i;
for (i=64; i<=s.length; i+=64) {
md5cycle(state, md5blk(s.substring(i-64, i)));
s = s.substring(i-64);
var tail = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0];
for (i=0; i<s.length; i++)
tail[i>>2] |= s.charCodeAt(i) << ((i%4) << 3);
tail[i>>2] |= 0x80 << ((i%4) << 3);
if (i > 55) {
md5cycle(state, tail);
for (i=0; i<16; i++) tail[i] = 0;
tail[14] = n*8;
md5cycle(state, tail);
return state;

/* there needs to be support for Unicode here,
 * unless we pretend that we can redefine the MD-5
 * algorithm for multi-byte characters (perhaps
 * by adding every four 16-bit characters and
 * shortening the sum to 32 bits). Otherwise
 * I suggest performing MD-5 as if every character
 * was two bytes--e.g., 0040 0025 = @%--but then
 * how will an ordinary MD-5 sum be matched?
 * There is no way to standardize text to something
 * like UTF-8 before transformation; speed cost is
 * utterly prohibitive. The JavaScript standard
 * itself needs to look at this: it should start
 * providing access to strings as preformed UTF-8
 * 8-bit unsigned value arrays.
function md5blk(s) { /* I figured global was faster.   */
var md5blks = [], i; /* Andy King said do it this way. */
for (i=0; i<64; i+=4) {
md5blks[i>>2] = s.charCodeAt(i)
+ (s.charCodeAt(i+1) << 8)
+ (s.charCodeAt(i+2) << 16)
+ (s.charCodeAt(i+3) << 24);
return md5blks;

var hex_chr = '0123456789abcdef'.split('');

function rhex(n)
var s='', j=0;
for(; j<4; j++)
s += hex_chr[(n >> (j * 8 + 4)) & 0x0F]
+ hex_chr[(n >> (j * 8)) & 0x0F];
return s;

function hex(x) {
for (var i=0; i<x.length; i++)
x[i] = rhex(x[i]);
return x.join('');

function md5(s) {
return hex(md51(s));

/* this function is much faster,
so if possible we use it. Some IEs
are the only ones I know of that
need the idiotic second function,
generated by an if clause.  */

function add32(a, b) {
return (a + b) & 0xFFFFFFFF;

if (md5('hello') != '5d41402abc4b2a76b9719d911017c592') {
function add32(x, y) {
var lsw = (x & 0xFFFF) + (y & 0xFFFF),
msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);

Then simply use the MD5 function, as shown below:

alert(md5("Test string"));

Another working JS Fiddle here

Query to select data between two dates with the format m/d/yyyy

This solution provides CONVERT_IMPLICIT operation for your condition in predicate

FROM xxx 
WHERE CAST(dates AS date) BETWEEN '1/1/2013' and '1/2/2013'

enter image description here


FROM xxx 
WHERE CONVERT(date, dates, 101) BETWEEN '1/1/2013' and '1/2/2013'

enter image description here

Demo on SQLFiddle

Automapper missing type map configuration or unsupported mapping - Error

I found the solution, Thanks all for reply.

category = (Categoies)AutoMapper.Mapper.Map(viewModel, category, typeof(CategoriesViewModel), typeof(Categoies));

But, I have already dont know the reason. I cant understand fully.

'System.Net.Http.HttpContent' does not contain a definition for 'ReadAsAsync' and no extension method

Make sure that you have installed the correct NuGet package in your console application:

<package id="Microsoft.AspNet.WebApi.Client" version="4.0.20710.0" />

and that you are targeting at least .NET 4.0.

This being said, your GetAllFoos function is defined to return an IEnumerable<Prospect> whereas in your ReadAsAsync method you are passing IEnumerable<Foo> which obviously are not compatible types.

Install-Package Microsoft.AspNet.WebApi.Client

Select project in project manager console

How can I save an image with PIL?

Try removing the . before the .bmp (it isn't matching BMP as expected). As you can see from the error, the save_handler is upper-casing the format you provided and then looking for a match in SAVE. However the corresponding key in that object is BMP (instead of .BMP).

I don't know a great deal about PIL, but from some quick searching around it seems that it is a problem with the mode of the image. Changing the definition of j to:

j = Image.fromarray(b, mode='RGB')

Seemed to work for me (however note that I have very little knowledge of PIL, so I would suggest using @mmgp's solution as s/he clearly knows what they are doing :) ). For the types of mode, I used this page - hopefully one of the choices there will work for you.

What is the difference between Numpy's array() and asarray() functions?

Here's a simple example that can demonstrate the difference.

The main difference is that array will make a copy of the original data and using different object we can modify the data in the original array.

import numpy as np
a = np.arange(0.0, 10.2, 0.12)
int_cvr = np.asarray(a, dtype = np.int64)

The contents in array (a), remain untouched, and still, we can perform any operation on the data using another object without modifying the content in original array.

setValue:forUndefinedKey: this class is not key value coding-compliant for the key

You're probably setting a value for a key in the alertView, which is not allowed. The key is in this case LoginScreen. I don't see any call to setValue(), so I assume it's somewhere else in the code.

How to pass ArrayList of Objects from one to another activity using Intent in android?

You can Pass Arraylist/Pojo using bundle like this ,

Intent intent = new Intent(MainActivity.this, SecondActivity.class);
Bundle args = new Bundle();

Get those values in SecondActivity like this

  Intent intent = getIntent();
        Bundle args = intent.getBundleExtra("BUNDLE");
  String filter = bundle.getString("imageSliders");

Web API Routing - api/{controller}/{action}/{id} "dysfunctions" api/{controller}/{id}

The possible reason can also be that you have not inherited Controller from ApiController. Happened with me took a while to understand the same.

PIL image to array (numpy array to array) - Python

I highly recommend you use the tobytes function of the Image object. After some timing checks this is much more efficient.

def jpg_image_to_array(image_path):
  Loads JPEG image into 3D Numpy array of shape 
  (width, height, channels)
  with as image:         
    im_arr = np.fromstring(image.tobytes(), dtype=np.uint8)
    im_arr = im_arr.reshape((image.size[1], image.size[0], 3))                                   
  return im_arr

The timings I ran on my laptop show

In [76]: %timeit np.fromstring(im.tobytes(), dtype=np.uint8)
1000 loops, best of 3: 230 µs per loop

In [77]: %timeit np.array(im.getdata(), dtype=np.uint8)
10 loops, best of 3: 114 ms per loop


Where can I find Android's default icons?


Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

I'm working on Windows Server 2012. .NET Extensibility 4.5 feature is on. WebDAVModule removed. I was still getting 500.21 error on ASP.NET route '/docs'.

Changing 'skipManagedModules' to false fixed the problem.

<applicationInitialization doAppInitAfterRestart="true" skipManagedModules="false">
        <add initializationPage="/docs" />    

Thanks to!topic/bonobo-git-server/GbdMXdDO4tI

Count all values in a matrix greater than a value

You can use numpy.count_nonzero, converting the whole into a one-liner:

za = numpy.count_nonzero(numpy.asarray(o31)<200)  #as written in the code

jQuery validate Uncaught TypeError: Cannot read property 'nodeName' of null

I had this problem and it was because the panel was outside of the [data-role="page"] element.

No MediaTypeFormatter is available to read an object of type 'String' from content with media type 'text/plain'

Or you can just create your own MediaTypeFormatter. I use this for text/html. If you add text/plain to it, it'll work for you too:

public class TextMediaTypeFormatter : MediaTypeFormatter
    public TextMediaTypeFormatter()
        SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));

    public override Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger)
        return ReadFromStreamAsync(type, readStream, content, formatterLogger, CancellationToken.None);

    public override async Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger, CancellationToken cancellationToken)
        using (var streamReader = new StreamReader(readStream))
            return await streamReader.ReadToEndAsync();

    public override bool CanReadType(Type type)
        return type == typeof(string);

    public override bool CanWriteType(Type type)
        return false;

Finally you have to assign this to the HttpMethodContext.ResponseFormatter property.

how to execute php code within javascript

You can't run PHP with javascript. JavaScript is a client side technology (runs in the users browser) and PHP is a server side technology (run on the server).

If you want to do this you have to make an ajax request to a PHP script and have that return the results you are looking for.

Why do you want to do this?

How to include Authorization header in cURL POST HTTP Request in PHP?

use "Content-type: application/x-www-form-urlencoded" instead of "application/json"

'negative' pattern matching in python

Why dont you match the OK SYS row and not return it.

for item in output:
    matchObj ="(OK SYS|\\.).*", item)
    if not matchObj:
        print "got item "  + item

Adding Http Headers to HttpClient

When it can be the same header for all requests or you dispose the client after each request you can use the DefaultRequestHeaders.Add option:


how to get the attribute value of an xml node using java

Below is the code to do it in VTD-XML

import com.ximpleware.*;

public class queryAttr{
     public static void main(String[] s) throws VTDException{
         VTDGen vg= new VTDGen();
         if (!vg.parseFile("input.xml", false))
            return false;
         VTDNav vn = vg.getNav();
         AutoPilot ap = new AutoPilot(vn);
         int i=0;
         while((i = ap.evalXPath())!=-1){
               system.out.println(" attr val ===>"+ vn.toString(i+1));


Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException:

Use component scanning as given below, if com.project.action.PasswordHintAction is annotated with stereotype annotations

<context:component-scan base-package="com.project.action"/>


I see your problem, in PasswordHintActionTest you are autowiring PasswordHintAction. But you did not create bean configuration for PasswordHintAction to autowire. Add one of stereotype annotation(@Component, @Service, @Controller) to PasswordHintAction like

public class PasswordHintAction extends BaseAction {
    private static final long serialVersionUID = -4037514607101222025L;
    private String username;

or create xml configuration in applicationcontext.xml like

<bean id="passwordHintAction" class="com.project.action.PasswordHintAction" />

rejected master -> master (non-fast-forward)

This is because you did some changes in your master so the project ask you to pull first. If you want to push it anyway you can use brute force by typing this:

git push -f origin master

Remember to first commit your changes:

git add .
git commit -m "Your commit message"

"Parser Error Message: Could not load type" in Global.asax

I encountered this error message and eventually discovered that the error message was misleading. In my case there appears to have been a routing issue in IIS which caused the global.asax from another site on the web server to be read thus generating the error.

In IIS, my site was bound to http:*80:webservices.local and contained an application called MyAPI. I received the dreaded message when calling the MyAPI application using the web server's ip address.

In order to successfully call my application I had to add a host file entry for webservices.local on all of the machines that called the MyAPI application. Then all of my requests had to be prefixed with http://webservices.local/MyAPI/ in order to route correctly.

Python: SyntaxError: keyword can't be an expression

sum.up is not a valid keyword argument name. Keyword arguments must be valid identifiers. You should look in the documentation of the library you are using how this argument really is called – maybe sum_up?

How to check whether dynamically attached event listener exists or not?

You could in theory piggyback addEventListener and removeEventListener to add remove a flag to the 'this' object. Ugly and I haven't tested ...

How to use Microsoft.Office.Interop.Excel on a machine without installed MS Office?

You can't use Microsoft.Office.Interop.Excel without having ms office installed.

Just search in google for some libraries, which allows to modify xls or xlsx:

Multiple HttpPost method in Web API controller

A web api endpoint (controller) is a single resource that accepts get/post/put/delete verbs. It is not a normal MVC controller.

Necessarily, at /api/VTRouting there can only be one HttpPost method that accepts the parameters you are sending. The function name does not matter, as long as you are decorating with the [http] stuff. I've never tried, though.

Edit: This does not work. In resolving, it seems to go by the number of parameters, not trying to model-bind to the type.

You can overload the functions to accept different parameters. I am pretty sure you would be OK if you declared it the way you do, but used different (incompatible) parameters to the methods. If the params are the same, you are out of luck as model binding won't know which one you meant.

public MyResult Route(MyRequestTemplate routingRequestTemplate) {...}

public MyResult TSPRoute(MyOtherTemplate routingRequestTemplate) {...}

This part works

The default template they give when you create a new one makes this pretty explicit, and I would say you should stick with this convention:

public class ValuesController : ApiController
    // GET is overloaded here.  one method takes a param, the other not.
    // GET api/values  
    public IEnumerable<string> Get() { .. return new string[] ... }
    // GET api/values/5
    public string Get(int id) { return "hi there"; }

    // POST api/values (OVERLOADED)
    public void Post(string value) { ... }
    public void Post(string value, string anotherValue) { ... }
    // PUT api/values/5
    public void Put(int id, string value) {}
    // DELETE api/values/5
    public void Delete(int id) {}

If you want to make one class that does many things, for ajax use, there is no big reason to not use a standard controller/action pattern. The only real difference is your method signatures aren't as pretty, and you have to wrap things in Json( returnValue) before you return them.


Overloading works just fine when using the standard template (edited to include) when using simple types. I've gone and tested the other way too, with 2 custom objects with different signatures. Never could get it to work.

  • Binding with complex objects doesn't look "deep", so thats a no-go
  • You could get around this by passing an extra param, on the query string
  • A better writeup than I can give on available options

This worked for me in this case, see where it gets you. Exception for testing only.

public class NerdyController : ApiController
    public void Post(string type, Obj o) { 
        throw new Exception("Type=" + type + ", o.Name=" + o.Name ); 

public class Obj {
    public string Name { get; set; }
    public string Age { get; set; }

And called like this form the console:

$.post("/api/Nerdy?type=white", { 'Name':'Slim', 'Age':'21' } )

MIME types missing in IIS 7 for ASP.NET - 404.17


I chose the "ISAPI & CGI Restrictions" after clicking the server name (not the site name) in IIS Manager, and right clicked the "ASP.NET v4.0.30319" lines and chose "Allow".

After turning on ASP.NET from "Programs and Features > Turn Windows features on or off", you must install ASP.NET from the Windows command prompt. The MIME types don't ever show up, but after doing this command, I noticed these extensions showed up under the IIS web site "Handler Mappings" section of IIS Manager.

C:\>cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>dir aspnet_reg*
 Volume in drive C is Windows
 Volume Serial Number is 8EE6-5DD0

 Directory of C:\Windows\Microsoft.NET\Framework64\v4.0.30319

03/18/2010  08:23 PM            19,296 aspnet_regbrowsers.exe
03/18/2010  08:23 PM            36,696 aspnet_regiis.exe
03/18/2010  08:23 PM           102,232 aspnet_regsql.exe
               3 File(s)        158,224 bytes
               0 Dir(s)  34,836,508,672 bytes free

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>aspnet_regiis.exe -i
Start installing ASP.NET (4.0.30319).
Finished installing ASP.NET (4.0.30319).


However, I still got this error. But if you do what I mentioned for the "Fix", this will go away.

HTTP Error 404.2 - Not Found
The page you are requesting cannot be served because of the ISAPI and CGI Restriction list settings on the Web server.

How to stretch the background image to fill a div

Modern CSS3 (recommended for the future & probably the best solution)

   background-size: cover;
   /* stretches background WITHOUT deformation so it would fill the background space,
      it may crop the image if the image's dimensions are in different ratio,
      than the element dimensions. */

Max. stretch without crop nor deformation (may not fill the background): background-size: contain;
Force absolute stretch (may cause deformation, but no crop): background-size: 100% 100%;

"Old" CSS "always working" way

Absolute positioning image as a first child of the (relative positioned) parent and stretching it to the parent size.


<div class="selector">
   <img src="path.extension" alt="alt text">
   <!-- some other content -->

Equivalent of CSS3 background-size: cover; :

To achieve this dynamically, you would have to use the opposite of contain method alternative (see below) and if you need to center the cropped image, you would need a JavaScript to do that dynamically - e.g. using jQuery:

$('.selector img').each(function(){ 
      "left": "50%", 
      "margin-left": "-"+( $(this).width()/2 )+"px", 
      "top": "50%", 
      "margin-top": "-"+( $(this).height()/2 )+"px" 

Practical example:
css crop like example

Equivalent of CSS3 background-size: contain; :

This one can be a bit tricky - the dimension of your background that would overflow the parent will have CSS set to 100% the other one to auto. Practical example: css stretching background as image

.selector img{
   position: absolute; top:0; left: 0;
   width: 100%;
   height: auto;
   /* -- OR -- */
   /* width: auto; 
      height: 100%; */

Equivalent of CSS3 background-size: 100% 100%; :

.selector img{
   position: absolute; top:0; left: 0;
   width: 100%;
   height: 100%;

PS: To do the equivalents of cover/contain in the "old" way completely dynamically (so you will not have to care about overflows/ratios) you would have to use javascript to detect the ratios for you and set the dimensions as described...

"Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))"


Just looking at the message it sounds like one or more of the components that you reference, or one or more of their dependencies is not registered properly.

If you know which component it is you can use regsvr32.exe to register it, just open a command prompt, go to the directory where the component is and type regsvr32 filename.dll (assuming it's a dll), if it works, try to run the code again otherwise come back here with the error.

If you don't know which component it is, try re-installing/repairing the GIS software (I assume you've installed some GIS software that includes the component you're trying to use).

How to convert image into byte array and byte array to base64 String in android?

Try this simple solution to convert file to base64 string

String base64String = imageFileToByte(file);

public String imageFileToByte(File file){

    Bitmap bm = BitmapFactory.decodeFile(file.getAbsolutePath());
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bm.compress(Bitmap.CompressFormat.JPEG, 100, baos); //bm is the bitmap object
    byte[] b = baos.toByteArray();
    return Base64.encodeToString(b, Base64.DEFAULT);

Where is HttpContent.ReadAsAsync?

Just right click in your project go Manage NuGet Packages search for Microsoft.AspNet.WebApi.Client install it and you will have access to the extension method.

Java - Convert image to Base64

Late GraveDig ... Just constrain your byte array to the file size.

FileInputStream fis = new FileInputStream( file );
byte[] byteArray= new byte[(int) file.length()];

What's the advantage of a Java enum versus a class with public static final fields?

  1. Type safety and value safety.
  2. Guaranteed singleton.
  3. Ability to define and override methods.
  4. Ability to use values in switch statement case statements without qualification.
  5. Built-in sequentialization of values via ordinal().
  6. Serialization by name not by value, which offers a degree of future-proofing.
  7. EnumSet and EnumMap classes.

Exporting to .xlsx using Microsoft.Office.Interop.Excel SaveAs Error

This is how you save the relevant file as a Excel12 (.xlsx) file... It is not as you would intuitively think i.e. using Excel.XlFileFormat.xlExcel12 but Excel.XlFileFormat.xlOpenXMLWorkbook. The actual C# command was

excelWorkbook.SaveAs(strFullFilePathNoExt, Excel.XlFileFormat.xlOpenXMLWorkbook, Missing.Value,
    Missing.Value, false, false, Excel.XlSaveAsAccessMode.xlNoChange, 
    Excel.XlSaveConflictResolution.xlUserResolution, true, 
    Missing.Value, Missing.Value, Missing.Value);

I hope this helps someone else in the future.

Missing.Value is found in the System.Reflection namespace.

Where and how is the _ViewStart.cshtml layout file linked?

From ScottGu's blog:

Starting with the ASP.NET MVC 3 Beta release, you can now add a file called _ViewStart.cshtml (or _ViewStart.vbhtml for VB) underneath the \Views folder of your project:

The _ViewStart file can be used to define common view code that you want to execute at the start of each View’s rendering. For example, we could write code within our _ViewStart.cshtml file to programmatically set the Layout property for each View to be the SiteLayout.cshtml file by default:

Because this code executes at the start of each View, we no longer need to explicitly set the Layout in any of our individual view files (except if we wanted to override the default value above).

Important: Because the _ViewStart.cshtml allows us to write code, we can optionally make our Layout selection logic richer than just a basic property set. For example: we could vary the Layout template that we use depending on what type of device is accessing the site – and have a phone or tablet optimized layout for those devices, and a desktop optimized layout for PCs/Laptops. Or if we were building a CMS system or common shared app that is used across multiple customers we could select different layouts to use depending on the customer (or their role) when accessing the site.

This enables a lot of UI flexibility. It also allows you to more easily write view logic once, and avoid repeating it in multiple places.

Also see this.

In a more general sense this ability of MVC framework to "know" about _Viewstart.cshtml is called "Coding by convention".

Convention over configuration (also known as coding by convention) is a software design paradigm which seeks to decrease the number of decisions that developers need to make, gaining simplicity, but not necessarily losing flexibility. The phrase essentially means a developer only needs to specify unconventional aspects of the application. For example, if there's a class Sale in the model, the corresponding table in the database is called “sales” by default. It is only if one deviates from this convention, such as calling the table “products_sold”, that one needs to write code regarding these names.


There's no magic to it. Its just been written into the core codebase of the MVC framework and is therefore something that MVC "knows" about. That why you don't find it in the .config files or elsewhere; it's actually in the MVC code. You can however override to alter or null out these conventions.

ajax jquery simple get request

var dataString = "flag=fetchmediaaudio&id="+id;

  type: "POST",
  url: "ajax.php",
  data: dataString,
  success: function(html)

Convert RGBA PNG to RGB with PIL

Here's a solution in pure PIL.

def blend_value(under, over, a):
    return (over*a + under*(255-a)) / 255

def blend_rgba(under, over):
    return tuple([blend_value(under[i], over[i], over[3]) for i in (0,1,2)] + [255])

white = (255, 255, 255, 255)

im =
p = im.load()
for y in range(im.size[1]):
    for x in range(im.size[0]):
        p[x,y] = blend_rgba(white, p[x,y])'/tmp/output.png')

m2eclipse error

I had a similar case for the default groovy compiler plugin

The solution was to install ME2 provided by Springsource according to this answer

Plugin execution not covered by lifecycle configuration maven error

This immediately solved the "Plugin execution not covered by lifecycle configuration" problem in Eclispe Juno.

how to convert an RGB image to numpy array?

Late answer, but I've come to prefer the imageio module to the other alternatives

import imageio
im = imageio.imread('abc.tiff')

Similar to cv2.imread(), it produces a numpy array by default, but in RGB form.

Basic Python client socket example

Here is a pretty simple socket program. This is about as simple as sockets get.

for the client program(CPU 1)

import socket

s = socket.socket()
host = '' # needs to be in quote
port = 1247
s.connect((host, port))
print s.recv(1024)
inpt = raw_input('type anything and click enter... ')
print "the message has been sent"

You have to replace the in line 4 with the IP number found in the second computers network settings.

For the server program(CPU 2)

import socket

s = socket.socket()
host = socket.gethostname()
port = 1247
while True:
    c, addr = s.accept()
    print("Connection accepted from " + repr(addr[1]))

    c.send("Server approved connection\n")
    print repr(addr[1]) + ": " + c.recv(1026)

Run the server program and then the client one.

Converting an OpenCV Image to Black and White

Pay attention, if you use cv.CV_THRESH_BINARY means every pixel greater than threshold becomes the maxValue (in your case 255), otherwise the value is 0. Obviously if your threshold is 0 everything becomes white (maxValue = 255) and if the value is 255 everything becomes black (i.e. 0).

If you don't want to work out a threshold, you can use the Otsu's method. But this algorithm only works with 8bit images in the implementation of OpenCV. If your image is 8bit use the algorithm like this:

cv.Threshold(im_gray_mat, im_bw_mat, threshold, 255, cv.CV_THRESH_BINARY | cv.CV_THRESH_OTSU);

No matter the value of threshold if you have a 8bit image.

Set environment variables on Mac OS X Lion

Setup your PATH environment variable on Mac OS

Open the Terminal program (this is in your Applications/Utilites folder by default). Run the following command

touch ~/.bash_profile; open ~/.bash_profile

This will open the file in the your default text editor.

For ANDROID SDK as example :

You need to add the path to your Android SDK platform-tools and tools directory. In my example I will use "/Development/android-sdk-macosx" as the directory the SDK is installed in. Add the following line:

export PATH=${PATH}:/Development/android-sdk-macosx/platform-tools:/Development/android-sdk-macosx/tools

Save the file and quit the text editor. Execute your .bash_profile to update your PATH.

source ~/.bash_profile

Now everytime you open the Terminal program you PATH will included the Android SDK.

Can you control how an SVG's stroke-width is drawn?

As people above have noted you'll either have to recalculate an offset to the stroke's path coordinates or double its width and then mask one side or the other, because not only does SVG not natively support Illustrator's stroke alignment, but PostScript doesn't either.

The specification for strokes in Adobe's PostScript Manual 2nd edition states: "4.5.1 Stroking: The stroke operator draws a line of some thickness along the current path. For each straight or curved segment in the path, stroke draws a line that is centered on the segment with sides parallel to the segment." (emphasis theirs)

The rest of the specification has no attributes for offsetting the line's position. When Illustrator lets you align inside or outside, it's recalculating the actual path's offset (because it's still computationally cheaper than overprinting then masking). The path coordinates in the .ai document are reference, not what gets rastered or exported to a final format.

Because Inkscape's native format is spec SVG, it can't offer a feature the spec lacks.

How do I create sql query for searching partial matches?

First of all, this approach won't scale in the large, you'll need a separate index from words to item (like an inverted index).

If your data is not large, you can do

SELECT DISTINCT(name) FROM mytable WHERE name LIKE '%mall%' OR description LIKE '%mall%'

using OR if you have multiple keywords.


You can return json in PHP this way:

header('Content-Type: application/json');
echo json_encode(array('foo' => 'bar'));

Get Base64 encode file-data from Input Form

My solution was use readAsBinaryString() and btoa() on its result.

uploadFileToServer(event) {
    var file = event.srcElement.files[0];
    var reader = new FileReader();

    reader.onload = function() {
    reader.onerror = function() {
        console.log('there are some problems');

Objects inside objects in javascript

You may have as many levels of Object hierarchy as you want, as long you declare an Object as being a property of another parent Object. Pay attention to the commas on each level, that's the tricky part. Don't use commas after the last element on each level:

{el1, el2, {el31, el32, el33}, {el41, el42}}

var MainObj = {_x000D_
  prop1: "prop1MainObj",_x000D_
  Obj1: {_x000D_
    prop1: "prop1Obj1",_x000D_
    prop2: "prop2Obj1",    _x000D_
    Obj2: {_x000D_
      prop1: "hey you",_x000D_
      prop2: "prop2Obj2"_x000D_
  Obj3: {_x000D_
    prop1: "prop1Obj3",_x000D_
    prop2: "prop2Obj3"_x000D_
  Obj4: {_x000D_
    prop1: true,_x000D_
    prop2: 3_x000D_
  }  _x000D_

How to mute an html5 video player using jQuery

If you don't want to jQuery, here's the vanilla JavaScript:

var video = document.getElementById("your-video-id");
video.muted= true;

var video = document.getElementById("your-video-id");
video.muted= false;

It will work for audio too, just put the element's id and it will work (and change the var name if you want, to 'media' or something suited for both audio/video as you like).

Why I cannot cout a string?

There are several problems with your code:

  1. WordList is not defined anywhere. You should define it before you use it.
  2. You can't just write code outside a function like this. You need to put it in a function.
  3. You need to #include <string> before you can use the string class and iostream before you use cout or endl.
  4. string, cout and endl live in the std namespace, so you can not access them without prefixing them with std:: unless you use the using directive to bring them into scope first.

Where is the Global.asax.cs file?

It don't create normally; you need to add it by yourself.

After adding Global.asax by

  • Right clicking your website -> Add New Item -> Global Application Class -> Add

You need to add a class

  • Right clicking App_Code -> Add New Item -> Class -> name it Global.cs -> Add

Inherit the newly generated by System.Web.HttpApplication and copy all the method created Global.asax to Global.cs and also add an inherit attribute to the Global.asax file.

Your Global.asax will look like this: -

<%@ Application Language="C#" Inherits="Global" %>

Your Global.cs in App_Code will look like this: -

public class Global : System.Web.HttpApplication
    public Global()
        // TODO: Add constructor logic here

    void Application_Start(object sender, EventArgs e)
        // Code that runs on application startup

    /// Many other events like begin request...e.t.c, e.t.c

Good way of getting the user's location in Android

This is my solution which works fairly well:

private Location bestLocation = null;
private Looper looper;
private boolean networkEnabled = false, gpsEnabled = false;

private synchronized void setLooper(Looper looper) {
    this.looper = looper;

private synchronized void stopLooper() {
    if (looper == null) return;

protected void runTask() {
    final LocationManager locationManager = (LocationManager) service
    final SharedPreferences prefs = getPreferences();
    final int maxPollingTime = Integer.parseInt(prefs.getString(
            POLLING_KEY, "0"));
    final int desiredAccuracy = Integer.parseInt(prefs.getString(
            DESIRED_KEY, "0"));
    final int acceptedAccuracy = Integer.parseInt(prefs.getString(
            ACCEPTED_KEY, "0"));
    final int maxAge = Integer.parseInt(prefs.getString(AGE_KEY, "0"));
    final String whichProvider = prefs.getString(PROVIDER_KEY, "any");
    final boolean canUseGps = whichProvider.equals("gps")
            || whichProvider.equals("any");
    final boolean canUseNetwork = whichProvider.equals("network")
            || whichProvider.equals("any");
    if (canUseNetwork)
        networkEnabled = locationManager
    if (canUseGps)
        gpsEnabled = locationManager
    // If any provider is enabled now and we displayed a notification clear it.
    if (gpsEnabled || networkEnabled) removeErrorNotification();
    if (gpsEnabled)
    if (networkEnabled)
    if (desiredAccuracy == 0
            || getLocationQuality(desiredAccuracy, acceptedAccuracy,
                    maxAge, bestLocation) != LocationQuality.GOOD) {
        // Define a listener that responds to location updates
        LocationListener locationListener = new LocationListener() {

            public void onLocationChanged(Location location) {
                if (desiredAccuracy != 0
                        && getLocationQuality(desiredAccuracy,
                                acceptedAccuracy, maxAge, bestLocation)
                                == LocationQuality.GOOD)

            public void onProviderEnabled(String provider) {
                if (isSameProvider(provider,
                        LocationManager.NETWORK_PROVIDER))networkEnabled =true;
                else if (isSameProvider(provider,
                        LocationManager.GPS_PROVIDER)) gpsEnabled = true;
                // The user has enabled a location, remove any error
                // notification
                if (canUseGps && gpsEnabled || canUseNetwork
                        && networkEnabled) removeErrorNotification();

            public void onProviderDisabled(String provider) {
                if (isSameProvider(provider,
                else if (isSameProvider(provider,
                        LocationManager.GPS_PROVIDER)) gpsEnabled = false;
                if (!gpsEnabled && !networkEnabled) {

            public void onStatusChanged(String provider, int status,
                    Bundle extras) {
                Log.i(LOG_TAG, "Provider " + provider + " statusChanged");
                if (isSameProvider(provider,
                        LocationManager.NETWORK_PROVIDER)) networkEnabled = 
                        status == LocationProvider.AVAILABLE
                        || status == LocationProvider.TEMPORARILY_UNAVAILABLE;
                else if (isSameProvider(provider,
                    gpsEnabled = status == LocationProvider.AVAILABLE
                      || status == LocationProvider.TEMPORARILY_UNAVAILABLE;
                // None of them are available, stop listening
                if (!networkEnabled && !gpsEnabled) {
                // The user has enabled a location, remove any error
                // notification
                else if (canUseGps && gpsEnabled || canUseNetwork
                        && networkEnabled) removeErrorNotification();
        if (networkEnabled || gpsEnabled) {
            // Register the listener with the Location Manager to receive
            // location updates
            if (canUseGps)
                        LocationManager.GPS_PROVIDER, 1000, 1,
                        locationListener, Looper.myLooper());
            if (canUseNetwork)
                        LocationManager.NETWORK_PROVIDER, 1000, 1,
                        locationListener, Looper.myLooper());
            Timer t = new Timer();
            t.schedule(new TimerTask() {

                public void run() {
            }, maxPollingTime * 1000);
        } else // No provider is enabled, show a notification
    if (getLocationQuality(desiredAccuracy, acceptedAccuracy, maxAge,
            bestLocation) != LocationQuality.BAD) {
        sendUpdate(new Event(EVENT_TYPE, locationToString(desiredAccuracy,
                acceptedAccuracy, maxAge, bestLocation)));
    } else Log.w(LOG_TAG, "LocationCollector failed to get a location");

private synchronized void showErrorNotification() {
    if (notifId != 0) return;
    ServiceHandler handler = service.getHandler();
    NotificationInfo ni = NotificationInfo.createSingleNotification(
    Intent intent = new Intent(
    ni.pendingIntent = PendingIntent.getActivity(service, 0, intent,
    Message msg = handler.obtainMessage(ServiceHandler.SHOW_NOTIFICATION);
    msg.obj = ni;
    notifId =;

private void removeErrorNotification() {
    if (notifId == 0) return;
    ServiceHandler handler = service.getHandler();
    if (handler != null) {
        Message msg = handler.obtainMessage(
                ServiceHandler.CLEAR_NOTIFICATION, notifId, 0);
        notifId = 0;

public void interrupt() {

private String locationToString(int desiredAccuracy, int acceptedAccuracy,
        int maxAge, Location location) {
    StringBuilder sb = new StringBuilder();
            "qual=%s time=%d prov=%s acc=%.1f lat=%f long=%f",
            getLocationQuality(desiredAccuracy, acceptedAccuracy, maxAge,
                    location), location.getTime() / 1000, // Millis to
                                                            // seconds
            location.getProvider(), location.getAccuracy(), location
                    .getLatitude(), location.getLongitude()));
    if (location.hasAltitude())
        sb.append(String.format(" alt=%.1f", location.getAltitude()));
    if (location.hasBearing())
        sb.append(String.format(" bearing=%.2f", location.getBearing()));
    return sb.toString();

private enum LocationQuality {

    public String toString() {
        if (this == GOOD) return "Good";
        else if (this == ACCEPTED) return "Accepted";
        else return "Bad";

private LocationQuality getLocationQuality(int desiredAccuracy,
        int acceptedAccuracy, int maxAge, Location location) {
    if (location == null) return LocationQuality.BAD;
    if (!location.hasAccuracy()) return LocationQuality.BAD;
    long currentTime = System.currentTimeMillis();
    if (currentTime - location.getTime() < maxAge * 1000
            && location.getAccuracy() <= desiredAccuracy)
        return LocationQuality.GOOD;
    if (acceptedAccuracy == -1
            || location.getAccuracy() <= acceptedAccuracy)
        return LocationQuality.ACCEPTED;
    return LocationQuality.BAD;

private synchronized void updateBestLocation(Location location) {
    bestLocation = getBestLocation(location, bestLocation);

protected Location getBestLocation(Location location,
        Location currentBestLocation) {
    if (currentBestLocation == null) {
        // A new location is always better than no location
        return location;
    if (location == null) return currentBestLocation;
    // Check whether the new location fix is newer or older
    long timeDelta = location.getTime() - currentBestLocation.getTime();
    boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
    boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
    boolean isNewer = timeDelta > 0;
    // If it's been more than two minutes since the current location, use
    // the new location
    // because the user has likely moved
    if (isSignificantlyNewer) {
        return location;
        // If the new location is more than two minutes older, it must be
        // worse
    } else if (isSignificantlyOlder) {
        return currentBestLocation;
    // Check whether the new location fix is more or less accurate
    int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation
    boolean isLessAccurate = accuracyDelta > 0;
    boolean isMoreAccurate = accuracyDelta < 0;
    boolean isSignificantlyLessAccurate = accuracyDelta > 200;
    // Check if the old and new location are from the same provider
    boolean isFromSameProvider = isSameProvider(location.getProvider(),
    // Determine location quality using a combination of timeliness and
    // accuracy
    if (isMoreAccurate) {
        return location;
    } else if (isNewer && !isLessAccurate) {
        return location;
    } else if (isNewer && !isSignificantlyLessAccurate
            && isFromSameProvider) {
        return location;
    return bestLocation;

/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
    if (provider1 == null) return provider2 == null;
    return provider1.equals(provider2);

Simple way to count character occurrences in a string

You can look at sorting the string -- treat it as a char array -- and then do a modified binary search which counts occurrences? But I agree with @tofutim that traversing it is the most efficient -- O(N) versus O(N * logN) + O(logN)

How to style the menu items on an Android action bar

I know its an old post, but just in case anyone is looking here. I added this to my style.xml and it worked for me.

<!-- This is the main theme parent -->
<style name="MyTabStyle">
    <item name="android:actionBarTabTextStyle">@style/MyTabTextStyle</item>

<style name="MyTabTextStyle" parent="@android:style/Widget.ActionBar.TabText">
    <item name="android:textAppearance">@android:style/TextAppearance.Medium</item>
    <item name="android:textSize">14sp</item>
    <item name="android:textStyle">bold</item>
    <item name="android:textColor">@color/pressed_skylogtheme</item>

'Incomplete final line' warning when trying to read a .csv file into R

The message indicates that the last line of the file doesn't end with an End Of Line (EOL) character (linefeed (\n) or carriage return+linefeed (\r\n)). The original intention of this message was to warn you that the file may be incomplete; most datafiles have an EOL character as the very last character in the file.

The remedy is simple:

  1. Open the file
  2. Navigate to the very last line of the file
  3. Place the cursor the end of that line
  4. Press return
  5. Save the file

How to update a menu item shown in the ActionBar?

in my case: invalidateOptionsMenu just re-setted the text to the original one, but directly accessing the menu item and re-writing the desire text worked without problems:

if (mnuTopMenuActionBar_ != null) {
    MenuItem mnuPageIndex = mnuTopMenuActionBar_

    if (mnuPageIndex != null) {
        if (getScreenOrientation() == 1) {
            mnuPageIndex.setTitle((i + 1) + " von " + pages);
        else {
                (i + 1) + " + " + (i + 2) + " " + " von " + pages);
        // invalidateOptionsMenu();

due to the comment below, I was able to access the menu item via the following code:

public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(, menu);
    mnuTopMenuActionBar_ = menu;
    return true;

Android, canvas: How do I clear (delete contents of) a canvas (= bitmaps), living in a surfaceView?

In my case, creating canvas every time worked for me, even though it's not memory-friendly

Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.image);
imageBitmap = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), bm.getConfig());
canvas = new Canvas(imageBitmap);
canvas.drawBitmap(bm, 0, 0, null);

How do I parse JSON with Objective-C?

With the perspective of the OS X v10.7 and iOS 5 launches, probably the first thing to recommend now is NSJSONSerialization, Apple's supplied JSON parser. Use third-party options only as a fallback if you find that class unavailable at runtime.

So, for example:

NSData *returnedData = ...JSON data, probably from a web request...

// probably check here that returnedData isn't nil; attempting
// NSJSONSerialization with nil data raises an exception, and who
// knows how your third-party library intends to react?

    NSError *error = nil;
    id object = [NSJSONSerialization

    if(error) { /* JSON was malformed, act appropriately here */ }

    // the originating poster wants to deal with dictionaries;
    // assuming you do too then something like this is the first
    // validation step:
    if([object isKindOfClass:[NSDictionary class]])
        NSDictionary *results = object;
        /* proceed with results as you like; the assignment to
        an explicit NSDictionary * is artificial step to get 
        compile-time checking from here on down (and better autocompletion
        when editing). You could have just made object an NSDictionary *
        in the first place but stylistically you might prefer to keep
        the question of type open until it's confirmed */
        /* there's no guarantee that the outermost object in a JSON
        packet will be a dictionary; if we get here then it wasn't,
        so 'object' shouldn't be treated as an NSDictionary; probably
        you need to report a suitable error condition */
    // the user is using iOS 4; we'll need to use a third-party solution.
    // If you don't intend to support iOS 4 then get rid of this entire
    // conditional and just jump straight to
    // NSError *error = nil;
    // [NSJSONSerialization JSONObjectWithData:...

afxwin.h file is missing in VC++ Express Edition

Including the header afxwin.h signalizes use of MFC. The following instructions (based on those on could help to get MFC code compiling:

  1. Download and install the Windows Driver Kit.

  2. Select menu Tools > Options… > Projects and Solutions > VC++ Directories.

  3. In the drop-down menu Show directories for select Include files.

  4. Add the following paths (replace $(WDK_directory) with the directory where you installed Windows Driver Kit in the first step):


  5. In the drop-down menu Show directories for select Library files and add (replace $(WDK_directory) like before):


  6. In the $(WDK_directory)\inc\mfc42\afxwin.inl file, edit the following lines (starting from 1033):

    _AFXWIN_INLINE CMenu::operator==(const CMenu& menu) const
        { return ((HMENU) menu) == m_hMenu; }
    _AFXWIN_INLINE CMenu::operator!=(const CMenu& menu) const
        { return ((HMENU) menu) != m_hMenu; }


    _AFXWIN_INLINE BOOL CMenu::operator==(const CMenu& menu) const
        { return ((HMENU) menu) == m_hMenu; }
    _AFXWIN_INLINE BOOL CMenu::operator!=(const CMenu& menu) const
        { return ((HMENU) menu) != m_hMenu; }

    In other words, add BOOL after _AFXWIN_INLINE.

"No resource identifier found for attribute 'showAsAction' in package 'android'"

From answer that was removed due to being written in Spanish:

All of the above fixes may not work in android studio. If you are using ANDROID STUDIO please use the following fix.


xmlns: compat = ""

on the menu label instead of

xmlns: compat = ""

Apache POI Excel - how to configure columns to be expanded?

If you know the count of your columns (f.e. it's equal to a collection list). You can simply use this one liner to adjust all columns of one sheet (if you use at least java 8):

IntStream.range(0, columnCount).forEach((columnIndex) -> sheet.autoSizeColumn(columnIndex));

Better way to shuffle two numpy arrays in unison

Just use numpy...

First merge the two input arrays 1D array is labels(y) and 2D array is data(x) and shuffle them with NumPy shuffle method. Finally split them and return.

import numpy as np

def shuffle_2d(a, b):
    rows= a.shape[0]
    if b.shape != (rows,1):
        b = b.reshape((rows,1))
    S = np.hstack((b,a))
    b, a  = S[:,0], S[:,1:]
    return a,b

features, samples = 2, 5
x, y = np.random.random((samples, features)), np.arange(samples)
x, y = shuffle_2d(train, test)

No grammar constraints (DTD or XML schema) detected for the document

In my case I have solved this annoying warning by simply adding the <!DOCTYPE xml> after the <?xml ... > tag.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xml>

System.Runtime.InteropServices.COMException (0x800A03EC)

I was seeing this same error when trying to save an excel file. The code worked fine when I was using MS Office 2003, but after upgrading to MS Office 2007 I started seeing this. It would happen anytime I tried to save an Excel file to a server or remote fie share.

My solution, though rudimentary, worked well. I just had the program save the file locally, like to the user's C:\ drive. Then use the "System.IO.File.Copy(File, Destination, Overwrite)" method to move the file to the server. Then you can delete the file on the C:\ drive.

Works great, and simple. But admittedly not the most elegant approach.

Hope this helps! I was having a ton of trouble finding any solutions on the web till this idea popped into my head.

How to Copy Contents of One Canvas to Another Canvas Locally

Actually you don't have to create an image at all. drawImage() will accept a Canvas as well as an Image object.

//grab the context from your destination canvas
var destCtx = destinationCanvas.getContext('2d');

//call its drawImage() function passing it the source canvas directly
destCtx.drawImage(sourceCanvas, 0, 0);

Way faster than using an ImageData object or Image element.

Note that sourceCanvas can be a HTMLImageElement, HTMLVideoElement, or a HTMLCanvasElement. As mentioned by Dave in a comment below this answer, you cannot use a canvas drawing context as your source. If you have a canvas drawing context instead of the canvas element it was created from, there is a reference to the original canvas element on the context under context.canvas.

Here is a jsPerf to demonstrate why this is the only right way to clone a canvas:

Create a new TextView programmatically then display it below another TextView

You're not assigning any id to the text view, but you're using tv.getId() to pass it to the addRule method as a parameter. Try to set a unique id via tv.setId(int).

You could also use the LinearLayout with vertical orientation, that might be easier actually. I prefer LinearLayout over RelativeLayouts if not necessary otherwise.

Strange Jackson exception being thrown when serializing Hibernate object

It's not ideal, but you could disable Jackson's auto-discovery of JSON properties, using @JsonAutoDetect at the class level. This would prevent it from trying to handle the Javassist stuff (and failing).

This means that you then have to annotate each getter manually (with @JsonProperty), but that's not necessarily a bad thing, since it keeps things explicit.

MySQL Foreign Key Error 1005 errno 150 primary key as foreign key

Give attention to CHARSET and COLLATE parameters when you create a table. In terms of FOREIGN KEY problems something like that:

CREATE TABLE yourTableName (
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

In my case i couldn´t create the table with FOREIGN KEY references. First i got the Error Code 1005 which pretty much says nothing. Then i added COLLATE and finally the error message complaining about CHARSET.

Error Code: 1253. COLLATION 'utf8_unicode_ci' is not valid for CHARACTER SET 'latin1'

After that correction my issue was solved.

Address already in use: JVM_Bind

Your local port 443 / 8181 / 3820 is used.

If you are on linux/unix:

  • use netstat -an and lsof -n to check who is using this port

If you are on windows

  • use netstat -an and tcpview to check.

Log4net does not write the log in the log file

Make sure the process (account) that the site is running under has privileges to write to the output directory.

In IIS 7 and above this is configured on the application pool and is normally the AppPool Identity, which will not normally have permission to write to all directories.

Check your event logs (application and security) to see if any exceptions were thrown.

How to find most common elements of a list?

If you are using Count, or have created your own Count-style dict and want to show the name of the item and the count of it, you can iterate around the dictionary like so:

top_10_words = Counter(my_long_list_of_words)
# Iterate around the dictionary
for word in top_10_words:
        # print the word
        print word[0]
        # print the count
        print word[1]

or to iterate through this in a template:

{% for word in top_10_words %}
        <p>Word: {{ word.0 }}</p>
        <p>Count: {{ word.1 }}</p>
{% endfor %}

Hope this helps someone

Python base64 data decode

(I know this is old but I wanted to post this for people like me who stumble upon it in the future) I personally just use this python code to decode base64 strings:

print open("FILE-WITH-STRING", "rb").read().decode("base64")

So you can run it in a bash script like this:

python -c 'print open("FILE-WITH-STRING", "rb").read().decode("base64")' > outputfile
file -i outputfile

twneale has also pointed out an even simpler solution: base64 -d So you can use it like this:

#Or You Can Do This
echo "STRING" | base64 -d > OUTPUTFILE

That will save the decoded string to outputfile and then attempt to identify file-type using either the file tool or you can try TrID. The following command will decode the string into a file and then use TrID to automatically identify the file's type and add the extension.

echo "STRING" | base64 -d > OUTPUTFILE; trid -ce OUTPUTFILE

How to make correct date format when writing data to Excel

Old question but still relevant. I've generated a dictionary that gets the appropriate datetime format for each region, here is the helper class I generated:

FWIW this is how I went about it:

  1. opened excel, manually entered a datetime into the first cell of a workbook
  2. opened the regions dialog in control panel
  3. used Spy to find out the HWND's of the regions combobox and the apply button so I can use SetForegroundWindow and SendKey to change the region (couldn't find how to change region through the Windows API)
  4. iterated through all regions and for each region asked Excel for the NumberFormat of the cell that contained the date, saved this data to into a file

.NET Global exception handler in console application

I just inherited an old VB.NET console application and needed to set up a Global Exception Handler. Since this question mentions VB.NET a few times and is tagged with VB.NET, but all the other answers here are in C#, I thought I would add the exact syntax for a VB.NET application as well.

Public Sub Main()
    REM Set up Global Unhandled Exception Handler.
    AddHandler System.AppDomain.CurrentDomain.UnhandledException, AddressOf MyUnhandledExceptionEvent

    REM Do other stuff
End Sub

Public Sub MyUnhandledExceptionEvent(ByVal sender As Object, ByVal e As UnhandledExceptionEventArgs)
    REM Log Exception here and do whatever else is needed
End Sub

I used the REM comment marker instead of the single quote here because Stack Overflow seemed to handle the syntax highlighting a bit better with REM.

How do I auto size columns through the Excel interop objects?

Have a look at this article, it's not an exact match to your problem, but suits it:

Get name of property as a string

Based on the answer which is already in the question and on this article: I am presenting my solution to this problem:

public static class PropertyNameHelper
    /// <summary>
    /// A static method to get the Propertyname String of a Property
    /// It eliminates the need for "Magic Strings" and assures type safety when renaming properties.
    /// See:
    /// </summary>
    /// <example>
    /// // Static Property
    /// string name = PropertyNameHelper.GetPropertyName(() => SomeClass.SomeProperty);
    /// // Instance Property
    /// string name = PropertyNameHelper.GetPropertyName(() => someObject.SomeProperty);
    /// </example>
    /// <typeparam name="T"></typeparam>
    /// <param name="propertyLambda"></param>
    /// <returns></returns>
    public static string GetPropertyName<T>(Expression<Func<T>> propertyLambda)
        var me = propertyLambda.Body as MemberExpression;

        if (me == null)
            throw new ArgumentException("You must pass a lambda of the form: '() => Class.Property' or '() => object.Property'");

        return me.Member.Name;
    /// <summary>
    /// Another way to get Instance Property names as strings.
    /// With this method you don't need to create a instance first.
    /// See the example.
    /// See:
    /// </summary>
    /// <example>
    /// string name = PropertyNameHelper((Firma f) => f.Firmenumsatz_Waehrung);
    /// </example>
    /// <typeparam name="T"></typeparam>
    /// <typeparam name="TReturn"></typeparam>
    /// <param name="expression"></param>
    /// <returns></returns>
    public static string GetPropertyName<T, TReturn>(Expression<Func<T, TReturn>> expression)
        MemberExpression body = (MemberExpression)expression.Body;
        return body.Member.Name;

And a Test which also shows the usage for instance and static properties:

public class PropertyNameHelperTest
    private class TestClass
        public static string StaticString { get; set; }
        public string InstanceString { get; set; }

    public void TestGetPropertyName()
        Assert.AreEqual("StaticString", PropertyNameHelper.GetPropertyName(() => TestClass.StaticString));

        Assert.AreEqual("InstanceString", PropertyNameHelper.GetPropertyName((TestClass t) => t.InstanceString));

Global variables in

You can create a variable with an application scope

What is the purpose of global.asax in

The root directory of a web application has a special significance and certain content can be present on in that folder. It can have a special file called as “Global.asax”. ASP.Net framework uses the content in the global.asax and creates a class at runtime which is inherited from HttpApplication. During the lifetime of an application, ASP.NET maintains a pool of Global.asax derived HttpApplication instances. When an application receives an http request, the ASP.Net page framework assigns one of these instances to process that request. That instance is responsible for managing the entire lifetime of the request it is assigned to and the instance can only be reused after the request has been completed when it is returned to the pool. The instance members in Global.asax cannot be used for sharing data across requests but static member can be. Global.asax can contain the event handlers of HttpApplication object and some other important methods which would execute at various points in a web application

Resizing an image in an HTML5 canvas

So what do you do if all the browsers (actually, Chrome 5 gave me quite good one) won't give you good enough resampling quality? You implement them yourself then! Oh come on, we're entering the new age of Web 3.0, HTML5 compliant browsers, super optimized JIT javascript compilers, multi-core(†) machines, with tons of memory, what are you afraid of? Hey, there's the word java in javascript, so that should guarantee the performance, right? Behold, the thumbnail generating code:

// returns a function that calculates lanczos weight
function lanczosCreate(lobes) {
    return function(x) {
        if (x > lobes)
            return 0;
        x *= Math.PI;
        if (Math.abs(x) < 1e-16)
            return 1;
        var xx = x / lobes;
        return Math.sin(x) * Math.sin(xx) / x / xx;

// elem: canvas element, img: image element, sx: scaled width, lobes: kernel radius
function thumbnailer(elem, img, sx, lobes) {
    this.canvas = elem;
    elem.width = img.width;
    elem.height = img.height; = "none";
    this.ctx = elem.getContext("2d");
    this.ctx.drawImage(img, 0, 0);
    this.img = img;
    this.src = this.ctx.getImageData(0, 0, img.width, img.height);
    this.dest = {
        width : sx,
        height : Math.round(img.height * sx / img.width),
    }; = new Array(this.dest.width * this.dest.height * 3);
    this.lanczos = lanczosCreate(lobes);
    this.ratio = img.width / sx;
    this.rcp_ratio = 2 / this.ratio;
    this.range2 = Math.ceil(this.ratio * lobes / 2);
    this.cacheLanc = {}; = {};
    this.icenter = {};
    setTimeout(this.process1, 0, this, 0);

thumbnailer.prototype.process1 = function(self, u) { = (u + 0.5) * self.ratio;
    self.icenter.x = Math.floor(;
    for (var v = 0; v < self.dest.height; v++) { = (v + 0.5) * self.ratio;
        self.icenter.y = Math.floor(;
        var a, r, g, b;
        a = r = g = b = 0;
        for (var i = self.icenter.x - self.range2; i <= self.icenter.x + self.range2; i++) {
            if (i < 0 || i >= self.src.width)
            var f_x = Math.floor(1000 * Math.abs(i -;
            if (!self.cacheLanc[f_x])
                self.cacheLanc[f_x] = {};
            for (var j = self.icenter.y - self.range2; j <= self.icenter.y + self.range2; j++) {
                if (j < 0 || j >= self.src.height)
                var f_y = Math.floor(1000 * Math.abs(j -;
                if (self.cacheLanc[f_x][f_y] == undefined)
                    self.cacheLanc[f_x][f_y] = self.lanczos(Math.sqrt(Math.pow(f_x * self.rcp_ratio, 2)
                            + Math.pow(f_y * self.rcp_ratio, 2)) / 1000);
                weight = self.cacheLanc[f_x][f_y];
                if (weight > 0) {
                    var idx = (j * self.src.width + i) * 4;
                    a += weight;
                    r += weight *[idx];
                    g += weight *[idx + 1];
                    b += weight *[idx + 2];
        var idx = (v * self.dest.width + u) * 3;[idx] = r / a;[idx + 1] = g / a;[idx + 2] = b / a;

    if (++u < self.dest.width)
        setTimeout(self.process1, 0, self, u);
        setTimeout(self.process2, 0, self);
thumbnailer.prototype.process2 = function(self) {
    self.canvas.width = self.dest.width;
    self.canvas.height = self.dest.height;
    self.ctx.drawImage(self.img, 0, 0, self.dest.width, self.dest.height);
    self.src = self.ctx.getImageData(0, 0, self.dest.width, self.dest.height);
    var idx, idx2;
    for (var i = 0; i < self.dest.width; i++) {
        for (var j = 0; j < self.dest.height; j++) {
            idx = (j * self.dest.width + i) * 3;
            idx2 = (j * self.dest.width + i) * 4;
  [idx2] =[idx];
  [idx2 + 1] =[idx + 1];
  [idx2 + 2] =[idx + 2];
    self.ctx.putImageData(self.src, 0, 0); = "block";

...with which you can produce results like these!

so anyway, here is a 'fixed' version of your example:

img.onload = function() {
    var canvas = document.createElement("canvas");
    new thumbnailer(canvas, img, 188, 3); //this produces lanczos3
    // but feel free to raise it up to 8. Your client will appreciate
    // that the program makes full use of his machine.

Now it's time to pit your best browsers out there and see which one will least likely increase your client's blood pressure!

Umm, where's my sarcasm tag?

(since many parts of the code is based on Anrieff Gallery Generator is it also covered under GPL2? I don't know)

actually due to limitation of javascript, multi-core is not supported.

Flatten an irregular list of lists

Iterative solution with Python 3

This solution may work with all objects except str and bytes.

from collections import Iterable
from collections import Iterator

def flat_iter(obj):
    stack = [obj]
    while stack:
        element = stack.pop()
        if element and isinstance(element, Iterator):
            except StopIteration:
        elif isinstance(element, Iterable) and not isinstance(element, (str, bytes)):
            yield element

tree_list = [[(1,2,3),(4,5,6, (7,8, 'next element is 5')), (5,6), [[[3,4,5],'foo1'],'foo2'],'foo3']]

not_iterable = 10

it1 = flat_iter(tree_list)
it2 = flat_iter(not_iterable)


[1, 2, 3, 4, 5, 6, 7, 8, 'next element is 5', 5, 6, 3, 4, 5, 'foo1', 'foo2', 'foo3']


HTTPS connection Python

Why haven't you tried httplib.HTTPSConnection? It doesn't do SSL validation but this isn't required to connect over https. Your code works fine with https connection:

>>> import httplib
>>> conn = httplib.HTTPSConnection("")
>>> conn.request("GET", "/")
>>> r1 = conn.getresponse()
>>> print r1.status, r1.reason
200 OK

How to set a Default Route (To an Area) in MVC

First, what version of MVC2 are you using? There have been significant changes from preview2 to RC.

Assuming you use the RC, I think you route-mapping should look differently. In the AreaRegistration.cs in your area, you can register some kind of default route, e.g.

            new { action = "Index", id = "", controller="MyRoute" }

The code above will send the user to the MyRouteController in our ShopArea per default.

Using an empty string as a second parameter should throw an exception, because a controller must be specified.

Of course you will have to change the default route in Global.asax so it doesn't interfere with this default route, e.g. by using a prefix for the main site.

Also see this thread and Haack's answer: MVC 2 AreaRegistration Routes Order

Hope this helps.

Does my application "contain encryption"?

If you use the Security framework or CommonCrypto libraries provided by Apple you do include crypto in your App and you have to answer yes - so simply because libraries were provided by Apple does not take you off the hook.

With regards to the original question, recent posts in the Apple Development Forums lead me to believe that you need to answer yes even if all you use is SSL.

"Could not load type [Namespace].Global" causing me grief

I had this issue when deploying on prod server only. In my other environments it works... I just deleted stuff in the bin folder then republish and it work after that.

In Python, how do I determine if an object is iterable?

def is_iterable(x):
        0 in x
    except TypeError:
        return False
        return True

This will say yes to all manner of iterable objects, but it will say no to strings in Python 2. (That's what I want for example when a recursive function could take a string or a container of strings. In that situation, asking forgiveness may lead to obfuscode, and it's better to ask permission first.)

import numpy

class Yes:
    def __iter__(self):
        yield 1;
        yield 2;
        yield 3;

class No:

class Nope:
    def __iter__(self):
        return 'nonsense'

assert is_iterable(Yes())
assert is_iterable(range(3))
assert is_iterable((1,2,3))   # tuple
assert is_iterable([1,2,3])   # list
assert is_iterable({1,2,3})   # set
assert is_iterable({1:'one', 2:'two', 3:'three'})   # dictionary
assert is_iterable(numpy.array([1,2,3]))
assert is_iterable(bytearray("not really a string", 'utf-8'))

assert not is_iterable(No())
assert not is_iterable(Nope())
assert not is_iterable("string")
assert not is_iterable(42)
assert not is_iterable(True)
assert not is_iterable(None)

Many other strategies here will say yes to strings. Use them if that's what you want.

import collections
import numpy

assert isinstance("string", collections.Iterable)
assert isinstance("string", collections.Sequence)
assert numpy.iterable("string")
assert iter("string")
assert hasattr("string", '__getitem__')

Note: is_iterable() will say yes to strings of type bytes and bytearray.

  • bytes objects in Python 3 are iterable True == is_iterable(b"string") == is_iterable("string".encode('utf-8')) There is no such type in Python 2.
  • bytearray objects in Python 2 and 3 are iterable True == is_iterable(bytearray(b"abc"))

The O.P. hasattr(x, '__iter__') approach will say yes to strings in Python 3 and no in Python 2 (no matter whether '' or b'' or u''). Thanks to @LuisMasuelli for noticing it will also let you down on a buggy __iter__.

Parser Error Message: Could not load type 'TestMvcApplication.MvcApplication'

For me, I had a DLL included with my project that had to be run in a 32-bit environment.

The server was configured to run the website in 32-bit mode, but I was not able to run the application on my 64-bit machine because the localhost folder had not been specified to run in 32-bit mode.

jQuery hasAttr checking to see if there is an attribute on an element

Late to the party, but... why not just this.hasAttribute("name")?

Refer This

Could not load file or assembly 'System.Data.SQLite'

I resolved this, oddly enough, by installing System.Data.SQLite via the Nuget GUI application, as opposed to the package manager console.

Installing via the console didn't include the dependencies this library needs to run.

ASP.NET MVC - Find Absolute Path to the App_Data folder from Controller

The most correct way is to use HttpContext.Current.Server.MapPath("~/App_Data");. This means you can only retrieve the path from a method where the HttpContext is available. It makes sense: the App_Data directory is a web project folder structure [1].

If you need the path to ~/App_Data from a class where you don't have access to the HttpContext you can always inject a provider interface using your IoC container:

public interface IAppDataPathProvider
    string GetAppDataPath();

Implement it using your HttpApplication:

public class AppDataPathProvider : IAppDataPathProvider
    public string GetAppDataPath()
        return MyHttpApplication.GetAppDataPath();

Where MyHttpApplication.GetAppDataPath looks like:

public class MyHttpApplication : HttpApplication
    // of course you can fetch&store the value at Application_Start
    public static string GetAppDataPath()
        return HttpContext.Current.Server.MapPath("~/App_Data");


How to calculate an angle from three points?

Very Simple Geometric Solution with Explanation

Few days ago, a fell into the same problem & had to sit with the math book. I solved the problem by combining and simplifying some basic formulas.

Lets consider this figure-


We want to know ?, so we need to find out a and ß first. Now, for any straight line-

y = m * x + c

Let- A = (ax, ay), B = (bx, by), and O = (ox, oy). So for the line OA-

oy = m1 * ox + c   ? c = oy - m1 * ox   ...(eqn-1)

ay = m1 * ax + c   ? ay = m1 * ax + oy - m1 * ox   [from eqn-1]
                   ? ay = m1 * ax + oy - m1 * ox
                   ? m1 = (ay - oy) / (ax - ox)
                   ? tan a = (ay - oy) / (ax - ox)   [m = slope = tan ?]   ...(eqn-2)

In the same way, for line OB-

tan ß = (by - oy) / (bx - ox)   ...(eqn-3)

Now, we need ? = ß - a. In trigonometry we have a formula-

tan (ß-a) = (tan ß + tan a) / (1 - tan ß * tan a)   ...(eqn-4)

After replacing the value of tan a (from eqn-2) and tan b (from eqn-3) in eqn-4, and applying simplification we get-

tan (ß-a) = ( (ax-ox)*(by-oy)+(ay-oy)*(bx-ox) ) / ( (ax-ox)*(bx-ox)-(ay-oy)*(by-oy) )


? = ß-a = tan^(-1) ( ((ax-ox)*(by-oy)+(ay-oy)*(bx-ox)) / ((ax-ox)*(bx-ox)-(ay-oy)*(by-oy)) )

That is it!

Now, take following figure-


This C# or, Java method calculates the angle (?)-

    private double calculateAngle(double P1X, double P1Y, double P2X, double P2Y,
            double P3X, double P3Y){

        double numerator = P2Y*(P1X-P3X) + P1Y*(P3X-P2X) + P3Y*(P2X-P1X);
        double denominator = (P2X-P1X)*(P1X-P3X) + (P2Y-P1Y)*(P1Y-P3Y);
        double ratio = numerator/denominator;

        double angleRad = Math.Atan(ratio);
        double angleDeg = (angleRad*180)/Math.PI;

            angleDeg = 180+angleDeg;

        return angleDeg;

ASP.NET MVC Custom Error Handling Application_Error Global.asax?

Instead of creating a new route for that, you could just redirect to your controller/action and pass the information via querystring. For instance:

protected void Application_Error(object sender, EventArgs e) {
  Exception exception = Server.GetLastError();

  HttpException httpException = exception as HttpException;

  if (httpException != null) {
    string action;

    switch (httpException.GetHttpCode()) {
      case 404:
        // page not found
        action = "HttpError404";
      case 500:
        // server error
        action = "HttpError500";
        action = "General";

      // clear error on server

      Response.Redirect(String.Format("~/Error/{0}/?message={1}", action, exception.Message));

Then your controller will receive whatever you want:

// GET: /Error/HttpError404
public ActionResult HttpError404(string message) {
   return View("SomeView", message);

There are some tradeoffs with your approach. Be very very careful with looping in this kind of error handling. Other thing is that since you are going through the pipeline to handle a 404, you will create a session object for all those hits. This can be an issue (performance) for heavily used systems.

Verify object attribute value with mockito

If you're using Java 8, you can use Lambda expressions to match.

import java.util.Optional;
import java.util.function.Predicate;

import org.hamcrest.BaseMatcher;
import org.hamcrest.Description;

public class LambdaMatcher<T> extends BaseMatcher<T>
    private final Predicate<T> matcher;
    private final Optional<String> description;

    public LambdaMatcher(Predicate<T> matcher)
        this(matcher, null);

    public LambdaMatcher(Predicate<T> matcher, String description)
        this.matcher = matcher;
        this.description = Optional.ofNullable(description);

    public boolean matches(Object argument)
        return matcher.test((T) argument);

    public void describeTo(Description description)

Example call

public void canFindEmployee()
    Employee employee = new Employee("John");

    verify(mockedDal).registerEmployee(argThat(new LambdaMatcher<>(e -> e.getName()

More info:

How can I create an array with key value pairs?

You can create the single value array key-value as

$new_row = array($row["datasource_id"]=>$row["title"]);

inside while loop, and then use array_merge function in loop to combine the each new $new_row array.

Is embedding background image data into CSS as Base64 good or bad practice?

It's not a good idea when you want your images and style information to be cached separately. Also if you encode a large image or a significant number of images in to your css file it will take the browser longer to download the file leaving your site without any of the style information until the download completes. For small images that you don't intend on changing often if ever it is a fine solution.

as far as generating the base64 encoding:

Using the AND and NOT Operator in Python

You should write :

if (self.a != 0) and (self.b != 0) :

"&" is the bit wise operator and does not suit for boolean operations. The equivalent of "&&" is "and" in Python.

A shorter way to check what you want is to use the "in" operator :

if 0 not in (self.a, self.b) :

You can check if anything is part of a an iterable with "in", it works for :

  • Tuples. I.E : "foo" in ("foo", 1, c, etc) will return true
  • Lists. I.E : "foo" in ["foo", 1, c, etc] will return true
  • Strings. I.E : "a" in "ago" will return true
  • Dict. I.E : "foo" in {"foo" : "bar"} will return true

As an answer to the comments :

Yes, using "in" is slower since you are creating an Tuple object, but really performances are not an issue here, plus readability matters a lot in Python.

For the triangle check, it's easier to read :

0 not in (self.a, self.b, self.c)


(self.a != 0) and (self.b != 0) and (self.c != 0) 

It's easier to refactor too.

Of course, in this example, it really is not that important, it's very simple snippet. But this style leads to a Pythonic code, which leads to a happier programmer (and losing weight, improving sex life, etc.) on big programs.

ASP.NET MVC - Set custom IIdentity or IPrincipal

All right, so i'm a serious cryptkeeper here by dragging up this very old question, but there is a much simpler approach to this, which was touched on by @Baserz above. And that is to use a combination of C# Extension methods and caching (Do NOT use session).

In fact, Microsoft has already provided a number of such extensions in the Microsoft.AspNet.Identity.IdentityExtensions namespace. For instance, GetUserId() is an extension method that returns the user Id. There is also GetUserName() and FindFirstValue(), which returns claims based on the IPrincipal.

So you need only include the namespace, and then call User.Identity.GetUserName() to get the users name as configured by ASP.NET Identity.

I'm not certain if this is cached, since the older ASP.NET Identity is not open sourced, and I haven't bothered to reverse engineer it. However, if it's not then you can write your own extension method, that will cache this result for a specific amount of time.

Is there a decorator to simply cache function return values?

Try joblib

from joblib import Memory
memory = Memory(cachedir=cachedir, verbose=0)
    def f(x):
        print('Running f(%s)' % x)
        return x

Application_Start not firing?

Note : a nice easy alternative to using the inbuilt "Visual Studio Development Server" or IIS Express (e.g. because you are developing against IIS and have particular settings you need for proper functioning of your app) is to simply stay running run in IIS (I use the Custom Web Server + hosts file entry + IIS binding to same domain)

  1. wait for debugging session to fire up ok
  2. then just make a whitespace edit to the root web.config and save the file
  3. refresh your page (Ctrl + F5)

Your breakpoint should be hit nicely, and you can continue to debug in your natural IIS habitat. Great !

Converting HTML files to PDF

Did you try WKHTMLTOPDF?

It's a simple shell utility, an open source implementation of WebKit. Both are free.

We've set a small tutorial here

EDIT( 2017 ):

If it was to build something today, I wouldn't go that route anymore.
But would use instead.
Probably stripping it of all its nodejs dependencies, to run in the browser.

Stack, Static, and Heap in C++

What are the problems of static and stack?

The problem with "static" allocation is that the allocation is made at compile-time: you can't use it to allocate some variable number of data, the number of which isn't known until run-time.

The problem with allocating on the "stack" is that the allocation is destroyed as soon as the subroutine which does the allocation returns.

I could write an entire application without allocate variables in the heap?

Perhaps but not a non-trivial, normal, big application (but so-called "embedded" programs might be written without the heap, using a subset of C++).

What garbage collector does ?

It keeps watching your data ("mark and sweep") to detect when your application is no longer referencing it. This is convenient for the application, because the application doesn't need to deallocate the data ... but the garbage collector might be computationally expensive.

Garbage collectors aren't a usual feature of C++ programming.

What could you do manipulating the memory by yourself that you couldn't do using this garbage collector?

Learn the C++ mechanisms for deterministic memory deallocation:

  • 'static': never deallocated
  • 'stack': as soon as the variable "goes out of scope"
  • 'heap': when the pointer is deleted (explicitly deleted by the application, or implicitly deleted within some-or-other subroutine)

ASP.NET custom error page - Server.GetLastError() is null

A combination of what NailItDown and Victor said. The preferred/easiest way is to use your Global.Asax to store the error and then redirect to your custom error page.


    void Application_Error(object sender, EventArgs e) 
    // Code that runs when an unhandled error occurs
    Exception ex = Server.GetLastError();
    Application["TheException"] = ex; //store the error for later
    Server.ClearError(); //clear the error so we can continue onwards
    Response.Redirect("~/myErrorPage.aspx"); //direct user to error page

In addition, you need to set up your web.config:

    <customErrors mode="RemoteOnly" defaultRedirect="~/myErrorPage.aspx">

And finally, do whatever you need to with the exception you've stored in your error page:

protected void Page_Load(object sender, EventArgs e)

    // ... do stuff ...
    //we caught an exception in our Global.asax, do stuff with it.
    Exception caughtException = (Exception)Application["TheException"];
    //... do stuff ...

SQL Server Management Studio – tips for improving the TSQL coding process

If you drag from Object Explorer Columns node for a table it puts a CSV list of columns in the Query Window for you

get launchable activity name of package from adb

You don't need root to pull the apk files from /data/app. Sure, you might not have permissions to list the contents of that directory, but you can find the file locations of APKs with:

adb shell pm list packages -f

Then you can use adb pull:

adb pull <APK path from previous command>

and then aapt to get the information you want:

aapt dump badging <pulledfile.apk>

What is Python buffer type for?

An example usage:

>>> s = 'Hello world'
>>> t = buffer(s, 6, 5)
>>> t
<read-only buffer for 0x10064a4b0, size 5, offset 6 at 0x100634ab0>
>>> print t

The buffer in this case is a sub-string, starting at position 6 with length 5, and it doesn't take extra storage space - it references a slice of the string.

This isn't very useful for short strings like this, but it can be necessary when using large amounts of data. This example uses a mutable bytearray:

>>> s = bytearray(1000000)   # a million zeroed bytes
>>> t = buffer(s, 1)         # slice cuts off the first byte
>>> s[1] = 5                 # set the second element in s
>>> t[0]                     # which is now also the first element in t!

This can be very helpful if you want to have more than one view on the data and don't want to (or can't) hold multiple copies in memory.

Note that buffer has been replaced by the better named memoryview in Python 3, though you can use either in Python 2.7.

Note also that you can't implement a buffer interface for your own objects without delving into the C API, i.e. you can't do it in pure Python.

How to provide shadow to Button

Try this if this works for you

enter image description here


Bootstrap Navbar toggle button not working

If you will change the ID then Toggle will not working same problem was with me i just change

<div class="collapse navbar-collapse" id="defaultNavbar1">
    <ul class="nav navbar-nav">

id="defaultNavbar1" then toggle is working

How do I check if a string is unicode or ascii?

If your code needs to be compatible with both Python 2 and Python 3, you can't directly use things like isinstance(s,bytes) or isinstance(s,unicode) without wrapping them in either try/except or a python version test, because bytes is undefined in Python 2 and unicode is undefined in Python 3.

There are some ugly workarounds. An extremely ugly one is to compare the name of the type, instead of comparing the type itself. Here's an example:

# convert bytes (python 3) or unicode (python 2) to str
if str(type(s)) == "<class 'bytes'>":
    # only possible in Python 3
    s = s.decode('ascii')  # or  s = str(s)[2:-1]
elif str(type(s)) == "<type 'unicode'>":
    # only possible in Python 2
    s = str(s)

An arguably slightly less ugly workaround is to check the Python version number, e.g.:

if sys.version_info >= (3,0,0):
    # for Python 3
    if isinstance(s, bytes):
        s = s.decode('ascii')  # or  s = str(s)[2:-1]
    # for Python 2
    if isinstance(s, unicode):
        s = str(s)

Those are both unpythonic, and most of the time there's probably a better way.

If else in stored procedure sql server

Instead of writing:

Select top 1 ParLngId from T_Param where ParStrNom = 'Extranet Client'


Select top 1 ParLngId from T_Param where ParStrNom IN 'Extranet Client'

i.e. replace '=' sign by 'IN'

How do I shutdown, restart, or log off Windows via a bat file?

You're probably aware of this, but just in case: it's much easier to just type shutdown -r (or whatever command you like) into the "Run" box and hit enter.

Saves leaving batch files lying around everywhere.

What are the differences in die() and exit() in PHP?

They sound about the same, however, the exit() also allows you to set the exit code of your PHP script.

Usually you don't really need this, but when writing console PHP scripts, you might want to check with for example Bash if the script completed everything in the right way.

Then you can use exit() and catch that later on. Die() however doesn't support that.

Die() always exists with code 0. So essentially a die() command does the following:

echo "I am going to die";

Which is the same as:

die("I am going to die");

Can you have a <span> within a <span>?

HTML4 specification states that:

Inline elements may contain only data and other inline elements

Span is an inline element, therefore having span inside span is valid. There's a related question: Can <span> tags have any type of tags inside them? which makes it completely clear.

HTML5 specification (including the most current draft of HTML 5.3 dated November 16, 2017) changes terminology, but it's still perfectly valid to place span inside another span.

Store query result in a variable using in PL/pgSQL

Create Learning Table:

CREATE TABLE "public"."learning" (
    "api_id" int4 DEFAULT nextval('share_api_api_id_seq'::regclass) NOT NULL,
    "title" varchar(255) COLLATE "default"

Insert Data Learning Table:

INSERT INTO "public"."learning" VALUES ('1', 'Google AI-01');
INSERT INTO "public"."learning" VALUES ('2', 'Google AI-02');
INSERT INTO "public"."learning" VALUES ('3', 'Google AI-01');

Step: 01

        learn_id INT,
        learn_title VARCHAR
) AS $$
        title = pattern ;
END ; $$ LANGUAGE 'plpgsql';

Step: 02

SELECT * FROM get_all('Google AI-01');

Step: 03

DROP FUNCTION get_all();

Demo: enter image description here

Multi-statement Table Valued Function vs Inline Table Valued Function

In researching Matt's comment, I have revised my original statement. He is correct, there will be a difference in performance between an inline table valued function (ITVF) and a multi-statement table valued function (MSTVF) even if they both simply execute a SELECT statement. SQL Server will treat an ITVF somewhat like a VIEW in that it will calculate an execution plan using the latest statistics on the tables in question. A MSTVF is equivalent to stuffing the entire contents of your SELECT statement into a table variable and then joining to that. Thus, the compiler cannot use any table statistics on the tables in the MSTVF. So, all things being equal, (which they rarely are), the ITVF will perform better than the MSTVF. In my tests, the performance difference in completion time was negligible however from a statistics standpoint, it was noticeable.

In your case, the two functions are not functionally equivalent. The MSTV function does an extra query each time it is called and, most importantly, filters on the customer id. In a large query, the optimizer would not be able to take advantage of other types of joins as it would need to call the function for each customerId passed. However, if you re-wrote your MSTV function like so:

RETURNS @CustomerOrder TABLE
    SaleOrderID    INT         NOT NULL,
    CustomerID      INT         NOT NULL,
    OrderDate       DATETIME    NOT NULL,
    OrderQty        INT         NOT NULL
    INSERT @CustomerOrder
    SELECT a.SalesOrderID, a.CustomerID, a.OrderDate, b.OrderQty
    FROM Sales.SalesOrderHeader a 
        INNER JOIN Sales.SalesOrderHeader b
            ON a.SalesOrderID = b.SalesOrderID
        INNER JOIN Production.Product c 
            ON b.ProductID = c.ProductID
    WHERE a.OrderDate = (
                        Select Max(SH1.OrderDate)
                        FROM Sales.SalesOrderHeader As SH1
                        WHERE SH1.CustomerID = A.CustomerId

In a query, the optimizer would be able to call that function once and build a better execution plan but it still would not be better than an equivalent, non-parameterized ITVS or a VIEW.

ITVFs should be preferred over a MSTVFs when feasible because the datatypes, nullability and collation from the columns in the table whereas you declare those properties in a multi-statement table valued function and, importantly, you will get better execution plans from the ITVF. In my experience, I have not found many circumstances where an ITVF was a better option than a VIEW but mileage may vary.

Thanks to Matt.


Since I saw this come up recently, here is an excellent analysis done by Wayne Sheffield comparing the performance difference between Inline Table Valued functions and Multi-Statement functions.

His original blog post.

Copy on SQL Server Central

Adding an assets folder in Android Studio

To specify any additional asset folder I've used this with my Gradle. This adds moreAssets, a folder in the project root, to the assets.

android {
    sourceSets {
        main.assets.srcDirs += '../moreAssets'

jQuery Ajax requests are getting cancelled without being sent

(Using Web Forms ASP.NET)

My issue was I was trying to fire Ajax off the click event of a submit button that had a server side click event setup. I had to make the button just a simple button (i.e. <input type="button"> )

How to use onSavedInstanceState example please

Basically onSaveInstanceState(Bundle outBundle) will give you a bundle. When you look at the Bundle class, you will see that you can put lots of different stuff inside it. At the next call of onCreate(), you just get that Bundle back as an argument. Then you can read your values again and restore your activity.

Lets say you have an activity with an EditText. The user wrote some text inside it. After that the system calls your onSaveInstanceState(). You read the text from the EditText and write it into the Bundle via Bundle.putString("edit_text_value", theValue).

Now onCreate is called. You check if the supplied bundle is not null. If thats the case, you can restore your value via Bundle.getString("edit_text_value") and put it back into your EditText.

How to insert element into arrays at specific position?

easy way.. using array_splice()

$array_1 = array(
  '0' => 'zero',
  '1' => 'one',
  '2' => 'two',
  '3' => 'three',

$addArray = array('sample_key' => 'sample_value');

array_splice($rs, 3, 0, $addArray);


    [0] => zero
    [1] => one
    [2] => two
    [3] => sample_value
    [4] => three

How do I execute a stored procedure in a SQL Agent job?

You just need to add this line to the window there:

exec (your stored proc name) (and possibly add parameters)

What is your stored proc called, and what parameters does it expect?

Excel Create Collapsible Indented Row Hierarchies

A much easier way is to go to Data and select Group or Subtotal. Instant collapsible rows without messing with pivot tables or VBA.

Is there a way to get a collection of all the Models in your Rails app?

I can't comment yet, but I think sj26 answer should be the top answer. Just a hint:

Rails.application.eager_load! unless Rails.configuration.cache_classes

How do I force Robocopy to overwrite files?

I did this for a home folder where all the folders are on the desktops of the corresponding users, reachable through a shortcut which did not have the appropriate permissions, so that users couldn't see it even if it was there. So I used Robocopy with the parameter to overwrite the file with the right settings:

FOR /F "tokens=*" %G IN ('dir /b') DO robocopy  "\\server02\Folder with shortcut" "\\server02\home\%G\Desktop" /S /A /V /log+:C:\RobocopyShortcut.txt /XF *.url *.mp3 *.hta *.htm *.mht *.js *.IE5 *.css *.temp *.html *.svg *.ocx *.3gp *.opus *.zzzzz *.avi *.bin *.cab *.mp4 *.mov *.mkv *.flv *.tiff *.tif *.asf *.webm *.exe *.dll *.dl_ *.oc_ *.ex_ *.sy_ *.sys *.msi *.inf *.ini *.bmp *.png *.gif *.jpeg *.jpg *.mpg *.db *.wav *.wma *.wmv *.mpeg *.tmp *.old *.vbs *.log *.bat *.cmd *.zip /SEC /IT /ZB /R:0

As you see there are many file types which I set to ignore (just in case), just set them for your needs or your case scenario.

It was tested on Windows Server 2012, and every switch is documented on Microsoft's sites and others.

Check if checkbox is NOT checked on click - jQuery

Do it like this

if (typeof $(this).attr("checked") == "undefined" )

// To check if checkbox is checked
if( $(this).attr("checked")=="checked")

Caesar Cipher Function in Python

The code is very large, but easy to understand. I think it fits your situation.

alphabet = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"
class CaesarCipher(object):    
    def __init__(self, shift):
        self.shift = shift
    def encode(self, str):
        encode = ''
        str = str.lower()
        for i in str:
            if i in alphabet:
                encode += alphabet[alphabet.index(i) + self.shift]
                encode += i
        return encode.upper()

    def decode(self, str):
        decode = ''
        str = str.lower()
        for i in str:
            if i in alphabet:
                decode += alphabet[alphabet.index(i) - self.shift]
                decode += i
        return decode.upper()

What is the reason for java.lang.IllegalArgumentException: No enum const class even though iterating through values() works just fine?

I had parsing enum problem when i was trying to pass Nullable Enum that we get from Backend. Of course it was working when we get value, but it was problem when the null comes up.

java.lang.IllegalArgumentException: No enum constant

Also the problem was when we at Parcelize read moment write some short if.

My solution for this was

1.Create companion object with parsing method.

enum class CarsType {
    @Json(name = "SMALL")
    @Json(name = "BIG")

    companion object {
        fun nullableValueOf(name: String?) = when (name) {
            null -> null
            else -> valueOf(name)

2. In Parcerable read place use it like this

data class CarData(
    val carId: String? = null,
    val carType: CarsType?,
    val data: String?
) : Parcelable {
    constructor(parcel: Parcel) : this(

Best way to store chat messages in a database?

There's nothing wrong with saving the whole history in the database, they are prepared for that kind of tasks.

Actually you can find here in Stack Overflow a link to an example schema for a chat: example

If you are still worried for the size, you could apply some optimizations to group messages, like adding a buffer to your application that you only push after some time (like 1 minute or so); that way you would avoid having only 1 line messages

Saving image from PHP URL

install wkhtmltoimage on your server then use my package for generate an image from url of your target.

How do I abort/cancel TPL Tasks?

I tried CancellationTokenSource but i can't do this. And i did do this with my own way. And it works.

namespace Blokick.Provider
    public class SignalRConnectProvider
        public SignalRConnectProvider()

        public bool IsStopRequested { get; set; } = false; //1-)This is important and default `false`.

        public async Task<string> ConnectTab()
            string messageText = "";
            for (int count = 1; count < 20; count++)
                if (count == 1)
                //Do stuff.

                //Do stuff.
                catch (Exception ex)
                //Do stuff.
                if (IsStopRequested) //3-)This is important. The control of the task stopping request. Must be true and in inside.
                    return messageText = "Task stopped."; //4-) And so return and exit the code and task.
                if (Connected)
                //Do stuff.
                if (count == 19)
                //Do stuff.
            return messageText;

And another class of the calling the method:

namespace Blokick.Views
    public partial class MessagePerson : ContentPage
        SignalRConnectProvider signalR = new SignalRConnectProvider();

        public MessagePerson()

            signalR.IsStopRequested = true; // 2-) And this. Make true if running the task and go inside if statement of the IsStopRequested property.

            if (signalR.ChatHubProxy != null)


How can we draw a vertical line in the webpage?

<hr> is not from struts. It is just an HTML tag.

So, take a look here: This link will give you a couple of tips.

How can I use numpy.correlate to do autocorrelation?

As I just ran into the same problem, I would like to share a few lines of code with you. In fact there are several rather similar posts about autocorrelation in stackoverflow by now. If you define the autocorrelation as a(x, L) = sum(k=0,N-L-1)((xk-xbar)*(x(k+L)-xbar))/sum(k=0,N-1)((xk-xbar)**2) [this is the definition given in IDL's a_correlate function and it agrees with what I see in answer 2 of question #12269834], then the following seems to give the correct results:

import numpy as np
import matplotlib.pyplot as plt

# generate some data
x = np.arange(0.,6.12,0.01)
y = np.sin(x)
# y = np.random.uniform(size=300)
yunbiased = y-np.mean(y)
ynorm = np.sum(yunbiased**2)
acor = np.correlate(yunbiased, yunbiased, "same")/ynorm
# use only second half
acor = acor[len(acor)/2:]


As you see I have tested this with a sin curve and a uniform random distribution, and both results look like I would expect them. Note that I used mode="same" instead of mode="full" as the others did.

Find the division remainder of a number

From Python 3.7, there is a new math.remainder() function:

from math import remainder


-2.0  # not 5

Note, as above, it's not the same as %.

Quoting the documentation:

math.remainder(x, y)

Return the IEEE 754-style remainder of x with respect to y. For finite x and finite nonzero y, this is the difference x - n*y, where n is the closest integer to the exact value of the quotient x / y. If x / y is exactly halfway between two consecutive integers, the nearest even integer is used for n. The remainder r = remainder(x, y) thus always satisfies abs(r) <= 0.5 * abs(y).

Special cases follow IEEE 754: in particular, remainder(x, math.inf) is x for any finite x, and remainder(x, 0) and remainder(math.inf, x) raise ValueError for any non-NaN x. If the result of the remainder operation is zero, that zero will have the same sign as x.

On platforms using IEEE 754 binary floating-point, the result of this operation is always exactly representable: no rounding error is introduced.

Issue29962 describes the rationale for creating the new function.

ImportError: No module named sqlalchemy

I just experienced the same problem using the virtual environment. For me installing the package using python from the venv worked:
.\venv\environment\Scripts\python.exe -m pip install flask-sqlalchemy

How to set a border for an HTML div tag

p{border: 1px solid red}
div{border: 5px solid blue}

Call me Ishmael.

Just don't call me late for dinner.

Call me Ishmael.

Just don't call me late for dinner.

Use Conditional formatting to turn a cell Red, yellow or green depending on 3 values in another sheet

  1. Highlight the range in question.
  2. On the Home tab, in the Styles Group, Click "Conditional Formatting".
  3. Click "Highlight cell rules"

For the first rule,

Click "greater than", then in the value option box, click on the cell criteria you want it to be less than, than use the format drop-down to select your color.

For the second,

Click "less than", then in the value option box, type "=.9*" and then click the cell criteria, then use the formatting just like step 1.

For the third,

Same as the second, except your formula is =".8*" rather than .9.

how to query child objects in mongodb

Assuming your "states" collection is like:

{"name" : "Spain", "cities" : [ { "name" : "Madrid" }, { "name" : null } ] }
{"name" : "France" }

The query to find states with null cities would be:

db.states.find({"" : {"$eq" : null, "$exists" : true}});

It is a common mistake to query for nulls as:

db.states.find({"" : null});

because this query will return all documents lacking the key (in our example it will return Spain and France). So, unless you are sure the key is always present you must check that the key exists as in the first query. /storage/emulated/0/New file.txt: open failed: EACCES (Permission denied)

If you are running in Android 29 then you have to use scoped storage or for now, you can bypass this issue by using:


in manifest in the application tag.

Python handling socket.error: [Errno 104] Connection reset by peer

You can try to add some time.sleep calls to your code.

It seems like the server side limits the amount of requests per timeunit (hour, day, second) as a security issue. You need to guess how many (maybe using another script with a counter?) and adjust your script to not surpass this limit.

In order to avoid your code from crashing, try to catch this error with try .. except around the urllib2 calls.

Can a foreign key refer to a primary key in the same table?

Eg: n sub-category level for categories .Below table primary-key id is referred by foreign-key sub_category_id

enter image description here

What is the largest TCP/IP network port number allowable for IPv4?

The port number is an unsigned 16-bit integer, so 65535.

Enable VT-x in your BIOS security settings (refer to documentation for your computer)

HP computer method:

Make sure your BIOS is updated before changing the settings. If you have an HP computer, they have an HP Support Assistant app you can configure to automatically install BIOS updates. Then follow the instructions on how to update BIOS.

Then you can look up which HP computer for how to change the BIOS in a search engine.

For an HP ZBook, follow these steps:

  1. Restart your computer with the shift key pressed (before you click restart) until a menu appears.
  2. Choose BIOS Setup on the screen (or press F10).
  3. Click on Troubleshoot.
  4. Using your arrow keys in this menu, go to Advanced Options.
  5. Select UEFI Firmware Settings.
  6. Select restart.
  7. It reboots into a Startup menu
  8. Choose BIOS Setup With arrow keys go to Advanced tab.
  9. Choose the System Options.
  10. Check both the Virtualization Technology (VTx) and the Virtualization Technology for Directed I/O (VTd) boxes.
  11. Go back to the Main tab and at bottom choose Save and Exit.
  12. Computer will restart.

Extract substring in Bash

Generic solution where the number can be anywhere in the filename, using the first of such sequences:

number=$(echo $filename | egrep -o '[[:digit:]]{5}' | head -n1)

Another solution to extract exactly a part of a variable:


If your filename always have the format stuff_digits_... you can use awk:

number=$(echo $filename | awk -F _ '{ print $2 }')

Yet another solution to remove everything except digits, use

number=$(echo $filename | tr -cd '[[:digit:]]')

How do I define and use an ENUM in Objective-C?

With current projects you may want to use the NS_ENUM() or NS_OPTIONS() macros.

typedef NS_ENUM(NSUInteger, PlayerState) {

How to use linux command line ftp with a @ sign in my username?

I've never seen the -u parameter. But if you want to use an "@", how about stating it as "\@"?

That way it should be interpreted as you intend. You know something like

ftp -u user\@[email protected]

querying WHERE condition to character length?

I think you want this:

select *
from dbo.table
where DATALENGTH(column_name) = 3

Return back to MainActivity from another activity

I'm used it and worked perfectly...

startActivity(new Intent(getApplicationContext(),MainActivity.class).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)); 

because Finish() use for 2 activities, not for multiple activities

How to determine if binary tree is balanced?

An empty tree is height-balanced. A non-empty binary tree T is balanced if:

1) Left subtree of T is balanced

2) Right subtree of T is balanced

3) The difference between heights of left subtree and right subtree is not more than 1.

/* program to check if a tree is height-balanced or not */
#define bool int

/* A binary tree node has data, pointer to left child
   and a pointer to right child */
struct node
  int data;
  struct node* left;
  struct node* right;

/* The function returns true if root is balanced else false
   The second parameter is to store the height of tree.  
   Initially, we need to pass a pointer to a location with value 
   as 0. We can also write a wrapper over this function */
bool isBalanced(struct node *root, int* height)
  /* lh --> Height of left subtree 
     rh --> Height of right subtree */   
  int lh = 0, rh = 0;  

  /* l will be true if left subtree is balanced 
    and r will be true if right subtree is balanced */
  int l = 0, r = 0;

  if(root == NULL)
    *height = 0;
     return 1;

  /* Get the heights of left and right subtrees in lh and rh 
    And store the returned values in l and r */   
  l = isBalanced(root->left, &lh);
  r = isBalanced(root->right,&rh);

  /* Height of current node is max of heights of left and 
     right subtrees plus 1*/   
  *height = (lh > rh? lh: rh) + 1;

  /* If difference between heights of left and right 
     subtrees is more than 2 then this node is not balanced
     so return 0 */
  if((lh - rh >= 2) || (rh - lh >= 2))
    return 0;

  /* If this node is balanced and left and right subtrees 
    are balanced then return true */
  else return l&&r;


/* Helper function that allocates a new node with the
   given data and NULL left and right pointers. */
struct node* newNode(int data)
    struct node* node = (struct node*)
                                malloc(sizeof(struct node));
    node->data = data;
    node->left = NULL;
    node->right = NULL;


int main()
  int height = 0;

  /* Constructed binary tree is
           /   \
         2      3
       /  \    /
     4     5  6
  struct node *root = newNode(1);  
  root->left = newNode(2);
  root->right = newNode(3);
  root->left->left = newNode(4);
  root->left->right = newNode(5);
  root->right->left = newNode(6);
  root->left->left->left = newNode(7);

  if(isBalanced(root, &height))
    printf("Tree is balanced");
    printf("Tree is not balanced");    

  return 0;

Time Complexity: O(n)

Why do I get access denied to data folder when using adb?

The problem could be that we need to specifically give adb root access in the developnent options in the latest CMs.. Here is what i did.

abc@abc-L655:~$ sudo adb kill-server
abc@abc-L655:~$ sudo adb root start-server * daemon not running. starting it now on port 5037 * * daemon started successfully * root access is disabled by system setting - enable in settings -> development options

after altering the development options...

abc@abc-L655:~$ sudo adb kill-server
abc@abc-L655:~$ sudo adb root start-server
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
restarting adbd as root
abc@abc-L655:~$ adb shell
root@android:/ # ls /data/ .... good to go.. 

How to create border in UIButton?

Swift 5

button.layer.borderWidth = 2

To change the colour of the border use

button.layer.borderColor = CGColor(srgbRed: 255/255, green: 126/255, blue: 121/255, alpha: 1)

Run Bash Command from PHP

You probably need to chdir to the correct directory before calling the script. This way you can ensure what directory your script is "in" before calling the shell command.

$old_path = getcwd();
$output = shell_exec('./ var1 var2');

How do I use properly CASE..WHEN in MySQL

I think part of it is that you're stating the value you're selecting after CASE, and then using WHEN x = y syntax afterward, which is a combination of two different methods of using CASE. It should either be

  WHEN a THEN ...
  WHEN b THEN ...


  WHEN x = a THEN ...
  WHEN x = b THEN ...

Change primary key column in SQL Server

Assuming that your current primary key constraint is called pk_history, you can replace the following lines:



with these:



If you don't know what the name of the PK is, you can find it with the following query:

 WHERE TABLE_NAME = 'history'

In C, how should I read a text file and print all strings

There are plenty of good answers here about reading it in chunks, I'm just gonna show you a little trick that reads all the content at once to a buffer and prints it.

I'm not saying it's better. It's not, and as Ricardo sometimes it can be bad, but I find it's a nice solution for the simple cases.

I sprinkled it with comments because there's a lot going on.

#include <stdio.h>
#include <stdlib.h>

char* ReadFile(char *filename)
   char *buffer = NULL;
   int string_size, read_size;
   FILE *handler = fopen(filename, "r");

   if (handler)
       // Seek the last byte of the file
       fseek(handler, 0, SEEK_END);
       // Offset from the first to the last byte, or in other words, filesize
       string_size = ftell(handler);
       // go back to the start of the file

       // Allocate a string that can hold it all
       buffer = (char*) malloc(sizeof(char) * (string_size + 1) );

       // Read it all in one operation
       read_size = fread(buffer, sizeof(char), string_size, handler);

       // fread doesn't set it so put a \0 in the last position
       // and buffer is now officially a string
       buffer[string_size] = '\0';

       if (string_size != read_size)
           // Something went wrong, throw away the memory and set
           // the buffer to NULL
           buffer = NULL;

       // Always remember to close the file.

    return buffer;

int main()
    char *string = ReadFile("yourfile.txt");
    if (string)

    return 0;

Let me know if it's useful or you could learn something from it :)

How do I update all my CPAN modules to their latest versions?

Try perl -MCPAN -e "upgrade /(.\*)/". It works fine for me.

html table span entire width?

Just FYI:

html should be table & width:100%. span should be margin: auto;

Why doesn't Git ignore my specified file?

Another possible reasona few instances of git clients running at the same time. For example "git shell" + "GitHub Desktop", etc.

This happened to me, I was using "GitHub Desktop" as the main client and it was ignoring some new .gitignore settings: commit after commit:

  1. You commit something.
  2. Next, commit: it ignores .gitignore settings. Commit includes lots of temp files mentioned in the .gitignore.
  3. Clear git cache; check whether .gitignore is UTF8; remove files -> commit -> move files back; skip 1 commit – nothing helped.

Reason: the Visual Studio Code editor was running in the background with the same opened repository. VS Code has built-in git control, and this makes some conflicts.

Solution: double-check multiple, hidden git clients and use only one git client at once, especially while clearing git cache.

How to create custom spinner like border around the spinner with down triangle on the right side?

You can achieve the following by using a single line in your spinner declaration in XML: enter image description here

Just add this: style="@android:style/Widget.Holo.Light.Spinner"

This is a default generated style in android. It doesn't contain borders around it though. For that you'd better search something on google.

Hope this helps.

UPDATE: AFter a lot of digging I got something which works well for introducing border around spinner.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="">
            <solid android:color="@android:color/white" />
            <corners android:radius="4dp" />
                android:color="#9E9E9E" />
                android:top="16dp" />

Place this in the drawable folder and use it as a background for spinner. Like this:


            android:spinnerMode="dialog" />


Invoking a PHP script from a MySQL trigger

I don't know if it's possible but I always pictured myself being able to do this with the CSV storage engine in MySQL. I don't know the details of this engine: but you can look into it and have a file watcher in your operating system that triggers a PHP call if the file is modified.

How to set text size in a button in html

Try this, its working in FF

button {
 font-family: Arial,Helvetica,sans-serif;
 font-size: 14px;

Tomcat 7 "SEVERE: A child container failed during start"

I solved a similar problem by updating the web.xml declaration to Servlet 4.0 specification as follows (I use Tomcat 9) :

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns=""
      <!-- ... (your content here) ... -->

You can check which servlet version Tomcat supports by refering to the chart on Tomcat's which version page.

What is the non-jQuery equivalent of '$(document).ready()'?

In plain vanilla JavaScript, with no libraries? It's an error. $ is simply an identifier, and is undefined unless you define it.

jQuery defines $ as it's own "everything object" (also known as jQuery so you can use it without conflicting with other libraries). If you're not using jQuery (or some other library that defines it), then $ will not be defined.

Or are you asking what the equivalent is in plain JavaScript? In that case, you probably want window.onload, which isn't exactly equivalent, but is the quickest and easiest way to get close to the same effect in vanilla JavaScript.

VBA vlookup reference in different sheet

Your code work fine, provided the value in Sheet2!D2 exists in Sheet1!A:A. If it does not then error 1004 is raised.

To handle this case, try

Sub Demo()
    Dim MyStringVar1 As Variant
    On Error Resume Next
    MyStringVar1 = Application.WorksheetFunction.VLookup(Range("D2"), _
      Worksheets("Sheet1").Range("A:C"), 1, False)
    On Error GoTo 0
    If IsEmpty(MyStringVar1) Then
        MsgBox "Value not found!"
    End If

    Range("E2") = MyStringVar1

End Sub

Is there a way to add a gif to a Markdown file?

From the Markdown Cheatsheet:

You can add it to your repo and reference it with an image tag:

![alt text]( "Logo Title Text 1")

![alt text][logo]

[logo]: "Logo Title Text 2"

Inline-style: alt text

Reference-style: alt text

Alternatively you can use the url directly:


How to extract a string between two delimiters

If there is only 1 occurrence, the answer of ivanovic is the best way I guess. But if there are many occurrences, you should use regexp:

\[(.*?)\] this is your pattern. And in each group(1) will get you your string.

Pattern p = Pattern.compile("\\[(.*?)\\]");
Matcher m = p.matcher(input);
{; //is your string. do what you want

Export query result to .csv file in SQL Server 2008

One more method worth to mention here:


NOTE: I don't see any network admin let you run powershell scripts

I am receiving warning in Facebook Application using PHP SDK

You need to ensure that any code that modifies the HTTP headers is executed before the headers are sent. This includes statements like session_start(). The headers will be sent automatically when any HTML is output.

Your problem here is that you're sending the HTML ouput at the top of your page before you've executed any PHP at all.

Move the session_start() to the top of your document :

<?php    session_start(); ?> <html> <head> <title>PHP SDK</title> </head> <body> <?php require_once 'src/facebook.php';    // more PHP code here. 

Converting string to Date and DateTime

If you want to get the last day of the current month you can do it with the following code.

$last_day_this_month  = date('F jS Y', strtotime(date('F t Y')));

JQuery Ajax - How to Detect Network Connection error when making Ajax call

here's what I did to alert user in case their network went down or upon page update failure:

  1. I have a div-tag on the page where I put current time and update this tag every 10 seconds. It looks something like this: <div id="reloadthis">22:09:10</div>

  2. At the end of the javascript function that updates the time in the div-tag, I put this (after time is updated with AJAX):

    var new_value = document.getElementById('reloadthis').innerHTML;
    var new_length = new_value.length;
        alert("NETWORK ERROR!");

That's it! You can replace the alert-part with anything you want, of course. Hope this helps.

How can I remove space (margin) above HTML header?

Try margin-top:

<header style="margin-top: -20px;">


Now I found relative position probably a better choice:

<header style="position: relative; top: -20px;">

ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist

Sometimes, the database will not be mounted correctly, so we need to mount it manually. For that, shut it down and start it up then mount. Log in as oracle user, then run the following commands:

sqlplus / as sysdba;
shutdown immediate;
startup nomount;
alter database mount;
alter database open;

Connect Device to Mac localhost Server?

also, make sure the server is listening for ur mobile device! for example, by default jekyll only answers requests made by the host machine. this solved my problem:

Connect to a locally built Jekyll Server using mobile devices in the LAN

How to escape apostrophe (') in MySql?

The MySQL documentation you cite actually says a little bit more than you mention. It also says,

A “'” inside a string quoted with “'” may be written as “''”.

(Also, you linked to the MySQL 5.0 version of Table 8.1. Special Character Escape Sequences, and the current version is 5.6 — but the current Table 8.1. Special Character Escape Sequences looks pretty similar.)

I think the Postgres note on the backslash_quote (string) parameter is informative:

This controls whether a quote mark can be represented by \' in a string literal. The preferred, SQL-standard way to represent a quote mark is by doubling it ('') but PostgreSQL has historically also accepted \'. However, use of \' creates security risks...

That says to me that using a doubled single-quote character is a better overall and long-term choice than using a backslash to escape the single-quote.

Now if you also want to add choice of language, choice of SQL database and its non-standard quirks, and choice of query framework to the equation, then you might end up with a different choice. You don't give much information about your constraints.

Dilemma: when to use Fragments vs Activities:

You are free to use one of those.
Basically, you have to evaluate which is the best one to your app. Think about how you will manage the business flow and how to store/manage data preferences.

Think about, how Fragments store garbage data. When you implement the fragment, you have a activity root to fill with fragment(s). So, if your trying to implement a lot of activities with too much fragments, you have to consider performance on your app, coz you're manipulating (coarsely speaks) two context lifecycle, remember the complexity.

Remember: should I use fragments? Why shouldn't I?


How can I calculate the time between 2 Dates in typescript

Use the getTime method to get the time in total milliseconds since 1970-01-01, and subtract those:

var time = new Date().getTime() - new Date("2013-02-20T12:01:04.753Z").getTime();

How to Scroll Down - JQuery

This can be used in to solve this problem

<div id='scrol'></div> 

in javascript use this


Convert date from String to Date format in Dataframes

You can also pass date format

df.withColumn("Date",to_date(unix_timestamp(df.col("your_date_column"), "your_date_format").cast("timestamp")))

For Example

import org.apache.spark.sql.functions._
val df = sc.parallelize(Seq("06 Jul 2018")).toDF("dateCol")
df.withColumn("Date",to_date(unix_timestamp(df.col("dateCol"), "dd MMM yyyy").cast("timestamp")))

Getting byte array through input type = file

This is a long post, but I was tired of all these examples that weren't working for me because they used Promise objects or an errant this that has a different meaning when you are using Reactjs. My implementation was using a DropZone with reactjs, and I got the bytes using a framework similar to what is posted at this following site, when nothing else above would work: . There were 2 keys, for me:

  1. You have to get the bytes from the event object, using and during a FileReader's onload function.
  2. I tried various combinations, but in the end, what worked was:

    const bytes ='base64,')[1];

Where e is the event. React requires const, you could use var in plain Javascript. But that gave me the base64 encoded byte string.

So I'm just going to include the applicable lines for integrating this as if you were using React, because that's how I was building it, but try to also generalize this, and add comments where necessary, to make it applicable to a vanilla Javascript implementation - caveated that I did not use it like that in such a construct to test it.

These would be your bindings at the top, in your constructor, in a React framework (not relevant to a vanilla Javascript implementation):

this.uploadFile = this.uploadFile.bind(this);
this.processFile = this.processFile.bind(this);
this.errorHandler = this.errorHandler.bind(this);
this.progressHandler = this.progressHandler.bind(this);

And you'd have onDrop={this.uploadFile} in your DropZone element. If you were doing this without React, this is the equivalent of adding the onclick event handler you want to run when you click the "Upload File" button.

<button onclick="uploadFile(event);" value="Upload File" />

Then the function (applicable lines... I'll leave out my resetting my upload progress indicator, etc.):

    // This is for React, only
      files: event,
    console.log('File count: ' + this.state.files.length);

    // You might check that the "event" has a file & assign it like this 
    // in vanilla Javascript:
    // var files =;
    // if (!files && files.length > 0)
    //     files = (event.dataTransfer ? event.dataTransfer.files : 
    //            event.originalEvent.dataTransfer.files);

    // You cannot use "files" as a variable in React, however:
    const in_files = this.state.files;

    // iterate, if files length > 0
    if (in_files.length > 0) {
      for (let i = 0; i < in_files.length; i++) {
      // use this, instead, for vanilla JS:
      // for (var i = 0; i < files.length; i++) {
        const a = i + 1;
        console.log('in loop, pass: ' + a);
        const f = in_files[i];  // or just files[i] in vanilla JS

        const reader = new FileReader();
        reader.onerror = this.errorHandler;
        reader.onprogress = this.progressHandler;
        reader.onload = this.processFile(f);

There was this question on that syntax, for vanilla JS, on how to get that file object:

JavaScript/HTML5/jQuery Drag-And-Drop Upload - "Uncaught TypeError: Cannot read property 'files' of undefined"

Note that React's DropZone will already put the File object into this.state.files for you, as long as you add files: [], to your this.state = { .... } in your constructor. I added syntax from an answer on that post on how to get your File object. It should work, or there are other posts there that can help. But all that Q/A told me was how to get the File object, not the blob data, itself. And even if I did fileData = new Blob([files[0]]); like in sebu's answer, which didn't include var with it for some reason, it didn't tell me how to read that blob's contents, and how to do it without a Promise object. So that's where the FileReader came in, though I actually tried and found I couldn't use their readAsArrayBuffer to any avail.

You will have to have the other functions that go along with this construct - one to handle onerror, one for onprogress (both shown farther below), and then the main one, onload, that actually does the work once a method on reader is invoked in that last line. Basically you are passing your event.dataTransfer.files[0] straight into that onload function, from what I can tell.

So the onload method calls my processFile() function (applicable lines, only):

processFile(theFile) {
  return function(e) {
    const bytes ='base64,')[1];

And bytes should have the base64 bytes.

Additional functions:

    switch ( {
        alert('File not found.');
        alert('File is not readable.');
        break;    // no operation
        alert('An error occurred reading this file.');

progressHandler(e) {
    if (e.lengthComputable){
      const loaded = Math.round((e.loaded / * 100);
      let zeros = '';

      // Percent loaded in string
      if (loaded >= 0 && loaded < 10) {
        zeros = '00';
      else if (loaded < 100) {
        zeros = '0';

      // Display progress in 3-digits and increase bar length
      document.getElementById("progress").textContent = zeros + loaded.toString();
      document.getElementById("progressBar").style.width = loaded + '%';

And applicable progress indicator markup:

<table id="tblProgress">
      <td><b><span id="progress">000</span>%</b> <span className="progressBar"><span id="progressBar" /></span></td>

And CSS:

.progressBar {
  background-color: rgba(255, 255, 255, .1);
  width: 100%;
  height: 26px;
#progressBar {
  background-color: rgba(87, 184, 208, .5);
  content: '';
  width: 0;
  height: 26px;


Inside processFile(), for some reason, I couldn't add bytes to a variable I carved out in this.state. So, instead, I set it directly to the variable, attachments, that was in my JSON object, RequestForm - the same object as my this.state was using. attachments is an array so I could push multiple files. It went like this:

  const fileArray = [];
  // Collect any existing attachments
  if (RequestForm.state.attachments.length > 0) {
    for (let i=0; i < RequestForm.state.attachments.length; i++) {
  // Add the new one to this.state
  // Update the state
    attachments: fileArray,

Then, because this.state already contained RequestForm:

this.stores = [

I could reference it as this.state.attachments from there on out. React feature that isn't applicable in vanilla JS. You could build a similar construct in plain JavaScript with a global variable, and push, accordingly, however, much easier:

var fileArray = new Array();  // place at the top, before any functions

// Within your processFile():
var newFileArray = [];
if (fileArray.length > 0) {
  for (var i=0; i < fileArray.length; i++) {
// Add the new one
// Now update the global variable
fileArray = newFileArray;

Then you always just reference fileArray, enumerate it for any file byte strings, e.g. var myBytes = fileArray[0]; for the first file.

Print values for multiple variables on the same line from within a for-loop

Try out cat and sprintf in your for loop.


cat(sprintf("\"%f\" \"%f\"\n", df$r, df$interest))

See here

Apply style to parent if it has child with css

It's not possible with CSS3. There is a proposed CSS4 selector, $, to do just that, which could look like this (Selecting the li element):

ul $li ul.sub { ... }

See the list of CSS4 Selectors here.

As an alternative, with jQuery, a one-liner you could make use of would be this:

$('ul li:has(ul.sub)').addClass('has_sub');

You could then go ahead and style the li.has_sub in your CSS.

jQuery equivalent to Prototype array.last()


It's not jQuery but another library you may find useful in addition to jQuery: Try SugarJS.

Sugar is a Javascript library that extends native objects with helpful methods. It is designed to be intuitive, unobtrusive, and let you do more with less code.

With SugarJS, you can do:

[1,2,3,4].last()    //  => 4

That means, your example does work out of the box:

var array = [1,2,3,4];
var lastEl = array.last();    //  => 4

More Info

How can I check what version/edition of Visual Studio is installed programmatically?

For anyone stumbling on this question, here is the answer if you are doing C++: You can check in your cpp code for vs version like the example bellow which links against a library based on vs version being 2015 or higher:

#if (_MSC_VER > 1800)
#pragma comment (lib, "legacy_stdio_definitions.lib")

This is done at link time and no extra run-time cost.

How do I clear/delete the current line in terminal?

Ctrl+A, Ctrl+K to wipe the current line in the terminal. You can then recall it with Ctrl+Y if you need.

How to set text color in submit button?

Use this CSS:

color: red;

that's all.

How to get xdebug var_dump to show full object/array

I know this is a super old post, but I figured this may still be helpful.

If you're comfortable with reading json format you could replace your var_dump with:

return json_encode($myvar);

I've been using this to help troubleshoot a service I've been building that has some deeply nested arrays. This will return every level of your array without truncating anything or requiring you to change your php.ini file.

Also, because the json_encoded data is a string it means you can write it to the error log easily


It probably isn't the best choice for every situation, but it's a choice!

Is it possible to use raw SQL within a Spring Repository

It is also possible to use Spring Data JDBC repository, which is a community project built on top of Spring Data Commons to access to databases with raw SQL, without using JPA.

It is less powerful than Spring Data JPA, but if you want lightweight solution for simple projects without using a an ORM like Hibernate, that a solution worth to try.

JQuery post JSON object to a server

To send json to the server, you first have to create json

function sendData() {
        url: '/helloworld',
        type: 'POST',
        contentType: 'application/json',
        data: JSON.stringify({
        dataType: 'json'

This is how you would structure the ajax request to send the json as a post var.

function sendData() {
        url: '/helloworld',
        type: 'POST',
        data: { json: JSON.stringify({
        dataType: 'json'

The json will now be in the json post var.

How do I select the parent form based on which submit button is clicked?

To get the form that the submit is inside why not just


Easiest & quickest path to the result.

How to get the index with the key in Python dictionary?

Use OrderedDicts:

>>> x = OrderedDict((("a", "1"), ("c", '3'), ("b", "2")))
>>> x["d"] = 4
>>> x.keys().index("d")
>>> x.keys().index("c")

For those using Python 3

>>> list(x.keys()).index("c")

Randomize a List<T>

 public Deck(IEnumerable<Card> initialCards) 
    cards = new List<Card>(initialCards);
    public void Shuffle() 
        List<Card> NewCards = new List<Card>();
        while (cards.Count > 0) 
            int CardToMove = random.Next(cards.Count);
        cards = NewCards;

public IEnumerable<string> GetCardNames() 

    string[] CardNames = new string[cards.Count];
    for (int i = 0; i < cards.Count; i++)
    CardNames[i] = cards[i].Name;
    return CardNames;

Deck deck1;
Deck deck2;
Random random = new Random();

public Form1() 



 private void ResetDeck(int deckNumber) 
    if (deckNumber == 1) 
      int numberOfCards = random.Next(1, 11);
      deck1 = new Deck(new Card[] { });
      for (int i = 0; i < numberOfCards; i++)
           deck1.Add(new Card((Suits)random.Next(4),(Values)random.Next(1, 14)));

    deck2 = new Deck();

private void reset1_Click(object sender, EventArgs e) {


private void shuffle1_Click(object sender, EventArgs e) 


private void moveToDeck1_Click(object sender, EventArgs e) 

    if (listBox2.SelectedIndex >= 0)
    if (deck2.Count > 0) {




throwing an exception in objective-c/cocoa

I use [NSException raise:format:] as follows:

[NSException raise:@"Invalid foo value" format:@"foo of %d is invalid", foo];

bash script use cut command at variable and store result at another variable

The awk solution is what I would use, but if you want to understand your problems with bash, here is a revised version of your script.

#!/bin/bash -vx

##config file with ip addresses like

while read line ; do
  ##this line is not correct, should strip :port and store to ip var
  ip=$( echo "$line" |cut -d\: -f1 )
  ping $ip
done < ${file}

You could write your top line as

for line in $(cat $file) ; do ...

(but not recommended).

You needed command substitution $( ... ) to get the value assigned to $ip

reading lines from a file is usually considered more efficient with the while read line ... done < ${file} pattern.

I hope this helps.

Setting up a websocket on Apache?

I struggled to understand the proxy settings for websockets for https therefore let me put clarity here what i realized.

First you need to enable proxy and proxy_wstunnel apache modules and the apache configuration file will look like this.

<IfModule mod_ssl.c>
    <VirtualHost _default_:443>
        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/your_project_public_folder

      SSLEngine on
      SSLCertificateFile    /etc/ssl/certs/path_to_your_ssl_certificate
      SSLCertificateKeyFile /etc/ssl/private/path_to_your_ssl_key

      <Directory /var/www/your_project_public_folder>
              Options Indexes FollowSymLinks
              AllowOverride All
              Require all granted
              php_flag display_errors On
      ProxyRequests Off 
      ProxyPass /wss/  ws://

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined

in your frontend application use the url "wss://" this is very important mostly if you are stuck with websockets you might be making mistake in the front end url. You probably putting url wrongly like below.

wss:// -> port no should not be mentioned
ws:// -> url should start with wss only.
wss:// -> url should end with / -> most important

also interesting part is the last /wss/ is same as proxypass value if you writing proxypass /ws/ then in the front end you should write /ws/ in the end of url.

Why is the GETDATE() an invalid identifier

Use ORACLE equivalent of getdate() which is sysdate . Read about here. Getdate() belongs to SQL Server , will not work on Oracle.

Other option is current_date

Webpack - webpack-dev-server: command not found

FYI, to access any script via command-line like you were trying, you need to have the script registered as a shell-script (or any kind of script like .js, .rb) in the system like these files in the the dir /usr/bin in UNIX. And, system must know where to find them. i.e. the location must be loaded in $PATH array.

In your case, the script webpack-dev-server is already installed somewhere inside ./node_modules directory, but system does not know how to access it. So, to access the command webpack-dev-server, you need to install the script in global scope as well.

$ npm install webpack-dev-server -g

Here, -g refers to global scope.

However, this is not recommended way because you might face version conflicting issues; so, instead you can set a command in npm's package.json file like:

  "scripts": {
    "start": "webpack-dev-server -d --config --content-base public/ --progress --colors"

This setting will let you access the script you want with simple command

$ npm start

So short to memorize and play. And, npm knows the location of the module webpack-dev-server.

How to upload multiple files using PHP, jQuery and AJAX

My solution

  • Assuming that form id = "my_form_id"
  • It detects the form method and form action from HTML

jQuery code

$('#my_form_id').on('submit', function(e) {
    var formData = new FormData($(this)[0]);
    var msg_error = 'An error has occured. Please try again later.';
    var msg_timeout = 'The server is not responding';
    var message = '';
    var form = $('#my_form_id');
        data: formData,
        async: false,
        cache: false,
        processData: false,
        contentType: false,
        url: form.attr('action'),
        type: form.attr('method'),
        error: function(xhr, status, error) {
            if (status==="timeout") {
            } else {
        success: function(response) {
        timeout: 7000

How to center links in HTML

The <p> will show up on a new line. Try wrapping all of your links in one single <p> tag:

<p style="text-align:center;"><a href="http//">Search</a><a href="Contact Us">Contact Us</a></p>

Formatting floats in a numpy array

You can use round function. Here some example

numpy.round([2.15295647e+01, 8.12531501e+00, 3.97113829e+00, 1.00777250e+01],2)
array([ 21.53,   8.13,   3.97,  10.08])

IF you want change just display representation, I would not recommended to alter printing format globally, as it suggested above. I would format my output in place.

>>a=np.array([2.15295647e+01, 8.12531501e+00, 3.97113829e+00, 1.00777250e+01])
>>> print([ "{:0.2f}".format(x) for x in a ])
['21.53', '8.13', '3.97', '10.08']

How to scanf only integer and repeat reading if the user enters non-numeric characters?

Use scanf("%d",&rows) instead of scanf("%s",input)

This allow you to get direcly the integer value from stdin without need to convert to int.

If the user enter a string containing a non numeric characters then you have to clean your stdin before the next scanf("%d",&rows).

your code could look like this:

#include <stdio.h>  
#include <stdlib.h> 

int clean_stdin()
    while (getchar()!='\n');
    return 1;

int main(void)  
    int rows =0;  
    char c;
        printf("\nEnter an integer from 1 to 23: ");

    } while (((scanf("%d%c", &rows, &c)!=2 || c!='\n') && clean_stdin()) || rows<1 || rows>23);

    return 0;  



scanf("%d%c", &rows, &c)

This means expecting from the user input an integer and close to it a non numeric character.

Example1: If the user enter aaddk and then ENTER, the scanf will return 0. Nothing capted

Example2: If the user enter 45 and then ENTER, the scanf will return 2 (2 elements are capted). Here %d is capting 45 and %c is capting \n

Example3: If the user enter 45aaadd and then ENTER, the scanf will return 2 (2 elements are capted). Here %d is capting 45 and %c is capting a


(scanf("%d%c", &rows, &c)!=2 || c!='\n')

In the example1: this condition is TRUE because scanf return 0 (!=2)

In the example2: this condition is FALSE because scanf return 2 and c == '\n'

In the example3: this condition is TRUE because scanf return 2 and c == 'a' (!='\n')


((scanf("%d%c", &rows, &c)!=2 || c!='\n') && clean_stdin())

clean_stdin() is always TRUE because the function return always 1

In the example1: The (scanf("%d%c", &rows, &c)!=2 || c!='\n') is TRUE so the condition after the && should be checked so the clean_stdin() will be executed and the whole condition is TRUE

In the example2: The (scanf("%d%c", &rows, &c)!=2 || c!='\n') is FALSE so the condition after the && will not checked (because what ever its result is the whole condition will be FALSE ) so the clean_stdin() will not be executed and the whole condition is FALSE

In the example3: The (scanf("%d%c", &rows, &c)!=2 || c!='\n') is TRUE so the condition after the && should be checked so the clean_stdin() will be executed and the whole condition is TRUE

So you can remark that clean_stdin() will be executed only if the user enter a string containing non numeric character.

And this condition ((scanf("%d%c", &rows, &c)!=2 || c!='\n') && clean_stdin()) will return FALSE only if the user enter an integer and nothing else

And if the condition ((scanf("%d%c", &rows, &c)!=2 || c!='\n') && clean_stdin()) is FALSE and the integer is between and 1 and 23 then the while loop will break else the while loop will continue

Strip HTML from Text JavaScript

An improvement to the accepted answer.

function strip(html)
   var tmp = document.implementation.createHTMLDocument("New").body;
   tmp.innerHTML = html;
   return tmp.textContent || tmp.innerText || "";

This way something running like this will do no harm:

strip("<img onerror='alert(\"could run arbitrary JS here\")' src=bogus>")

Firefox, Chromium and Explorer 9+ are safe. Opera Presto is still vulnerable. Also images mentioned in the strings are not downloaded in Chromium and Firefox saving http requests.

Is there a JavaScript function that can pad a string to get to a determined length?

A friend asked about using a JavaScript function to pad left. It turned into a little bit of an endeavor between some of us in chat to code golf it. This was the result:

function l(p,t,v){
    v+="";return v.length>=t?v:l(p,t,p+v); 

It ensures that the value to be padded is a string, and then if it isn't the length of the total desired length it will pad it once and then recurse. Here is what it looks like with more logical naming and structure

function padLeft(pad, totalLength, value){
    value = value.toString();

    if( value.length >= totalLength ){
        return value;
        return padLeft(pad, totalLength, pad + value);

The example we were using was to ensure that numbers were padded with 0 to the left to make a max length of 6. Here is an example set:

function l(p,t,v){v+="";return v.length>=t?v:l(p,t,p+v);}_x000D_
var vals = [6451,123,466750];_x000D_
var pad = l(0,6,vals[0]);// pad with 0's, max length 6_x000D_
var pads ={ return l(0,6,i) });_x000D_
document.write(pads.join("<br />"));

EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) on dispatch_semaphore_dispose

I landed here because of an XCTestCase, in which I'd disabled most of the tests by prefixing them with 'no_' as in no_testBackgroundAdding. Once I noticed that most of the answers had something to do with locks and threading, I realized the test contained a few instances of XCTestExpectation with corresponding waitForExpectations. They were all in the disabled tests, but apparently Xcode was still evaluating them at some level.

In the end I found an XCTestExpectation that was defined as @property but lacked the @synthesize. Once I added the synthesize directive, the EXC_BAD_INSTRUCTION disappeared.

What is console.log?

An example - suppose you want to know which line of code you were able to run your program (before it broke!), simply type in

console.log("You made it to line 26. But then something went very, very wrong.")

Count how many files in directory PHP

Working Demo


$directory = "../images/team/harry/"; // dir location
if (glob($directory . "*.*") != false)
 $filecount = count(glob($directory . "*.*"));
 echo $filecount;
 echo 0;


Smooth GPS data

Going back to the Kalman Filters ... I found a C implementation for a Kalman filter for GPS data here: I haven't tried it out yet, but it seems promising.

How often should you use git-gc?

Note that the downside of garbage-collecting your repository is that, well, the garbage gets collected. As we all know as computer users, files we consider garbage right now might turn out to be very valuable three days in the future. The fact that git keeps most of its debris around has saved my bacon several times – by browsing all the dangling commits, I have recovered much work that I had accidentally canned.

So don’t be too much of a neat freak in your private clones. There’s little need for it.

OTOH, the value of data recoverability is questionable for repos used mainly as remotes, eg. the place all the devs push to and/or pulled from. There, it might be sensible to kick off a GC run and a repacking frequently.

Inject service in app.config

You can use $inject service to inject a service in you config


    $provide.decorator("$exceptionHandler", function($delegate, $injector){
        return function(exception, cause){
            var $rootScope = $injector.get("$rootScope");
            $rootScope.addError({message:"Exception", reason:exception});
            $delegate(exception, cause);



PHP Warning: PHP Startup: Unable to load dynamic library

Note that you can also get this error if your PHP library doesn't have the "other" directory opening permission. In my particular case, I noticed this when using php -l to syntax check a script in my text editor. This meant that since my account was called "volomike", that account didn't have permission to run the libraries that the php command relied upon.

For instance, on Ubuntu 14.04, I had PHP5 installed automatically into the path /usr/lib/php5/20121212+lfs. However, because I was working in C++ in building some shared objects, I messed around with the directory permissions and screwed things up such that non-root accounts did not have the directory execute (directory open) permissions to view /usr/lib/php5/20121212+lfs. So, I typed the following command to rectify that problem:

sudo chmod o+x /usr/lib/php5/20121212+lfs.

Now when I do php -l example.php as a non-root user, it never gives me this "Unabled to load dynamic library" problem anymore.

Deep copy of a dict in python

A simpler (in my view) solution is to create a new dictionary and update it with the contents of the old one:


my_copy = {}

my_copy.update( my_dict )


Out[34]: 2

Out[35]: 1

The problem with this approach is it may not be 'deep enough'. i.e. is not recursively deep. good enough for simple objects but not for nested dictionaries. Here is an example where it may not be deep enough:



my_dict3={ 'b': my_dict1, 'c':my_dict2 }

my_copy = {}

my_copy.update( my_dict3 )


Out[42]: {'b': {'b': 'z'}, 'c': {'c': 3}}

By using Deepcopy() I can eliminate the semi-shallow behavior, but I think one must decide which approach is right for your application. In most cases you may not care, but should be aware of the possible pitfalls... final example:

import copy

my_copy2 = copy.deepcopy( my_dict3 )


Out[46]: {'b': {'b': 'z'}, 'c': {'c': 3}}

Change the background color of CardView programmatically

What you are looking for is:

CardView card = ...



Update: in XML


Can one class extend two classes?

If you are interested in using methods from multiple classes, the best way to approach to it is to use Composition instead of Inheritence

How to resize datagridview control when form resizes

Use control anchoring. Set property Anchor of your GridView to Top, Left, Right and it will resize with container. If your GridView are placed inside of some container (ex Panel) then Panel should be anchored too.

Laravel back button

One of the below solve your problem




How to find the difference in days between two dates?

Using mysql command

$ echo "select datediff('2013-06-20 18:12:54+08:00', '2013-05-30 18:12:54+08:00');"  | mysql -N

Result: 21

NOTE: Only the date parts of the values are used in the calculation


How to call a method in MainActivity from another class?

What I have done with no memory leaks or lint warnings is to use @f.trajkovski's method, but instead of using MainActivity, use WeakReference<MainActivity> instead.

public class MainActivity extends AppCompatActivity {
public static WeakReference<MainActivity> weakActivity;
// etc..
 public static MainActivity getmInstanceActivity() {
    return weakActivity.get();

Then in MainActivity OnCreate()

weakActivity = new WeakReference<>(MainActivity.this);

Then in another class


Works like a charm

Including .cpp files

When you say #include "foop.cpp", it is as if you had copied the entire contents of foop.cpp and pasted it into main.cpp.

So when you compile main.cpp, the compiler emits a main.obj that contains the executable code for two functions: main and foo.

When you compile foop.cpp itself, the compiler emits a foop.obj that contains the executable code for function foo.

When you link them together, the compiler sees two definitions for function foo (one from main.obj and the other from foop.obj) and complains that you have multiple definitions.

How can I set the Secure flag on an ASP.NET Session Cookie?

Building upon @Mark D's answer I would use web.config transforms to set all the various cookies to Secure. This includes setting anonymousIdentification cookieRequireSSL and httpCookies requireSSL.

To that end you'd setup your web.Release.config as:

<?xml version="1.0"?>
<configuration xmlns:xdt="">
    <httpCookies xdt:Transform="SetAttributes(httpOnlyCookies)" httpOnlyCookies="true" />
    <httpCookies xdt:Transform="SetAttributes(requireSSL)" requireSSL="true" />
    <anonymousIdentification xdt:Transform="SetAttributes(cookieRequireSSL)" cookieRequireSSL="true" /> 

If you're using Roles and Forms Authentication with the ASP.NET Membership Provider (I know, it's ancient) you'll also want to set the roleManager cookieRequireSSL and the forms requireSSL attributes as secure too. If so, your web.release.config might look like this (included above plus new tags for membership API):

<?xml version="1.0"?>
<configuration xmlns:xdt="">
    <httpCookies xdt:Transform="SetAttributes(httpOnlyCookies)" httpOnlyCookies="true" />
    <httpCookies xdt:Transform="SetAttributes(requireSSL)" requireSSL="true" />
    <anonymousIdentification xdt:Transform="SetAttributes(cookieRequireSSL)" cookieRequireSSL="true" /> 
    <roleManager xdt:Transform="SetAttributes(cookieRequireSSL)" cookieRequireSSL="true" />
        <forms xdt:Transform="SetAttributes(requireSSL)" requireSSL="true" />

Background on web.config transforms here:

Obviously this goes beyond the original question of the OP but if you don't set them all to secure you can expect that a security scanning tool will notice and you'll see red flags appear on the report. Ask me how I know. :)

hash function for string

First, you generally do not want to use a cryptographic hash for a hash table. An algorithm that's very fast by cryptographic standards is still excruciatingly slow by hash table standards.

Second, you want to ensure that every bit of the input can/will affect the result. One easy way to do that is to rotate the current result by some number of bits, then XOR the current hash code with the current byte. Repeat until you reach the end of the string. Note that you generally do not want the rotation to be an even multiple of the byte size either.

For example, assuming the common case of 8 bit bytes, you might rotate by 5 bits:

int hash(char const *input) { 
    int result = 0x55555555;

    while (*input) { 
        result ^= *input++;
        result = rol(result, 5);

Edit: Also note that 10000 slots is rarely a good choice for a hash table size. You usually want one of two things: you either want a prime number as the size (required to ensure correctness with some types of hash resolution) or else a power of 2 (so reducing the value to the correct range can be done with a simple bit-mask).

How to do a regular expression replace in MySQL?

If you are using MariaDB or MySQL 8.0, they have a function

REGEXP_REPLACE(col, regexp, replace)

See MariaDB docs and PCRE Regular expression enhancements

Note that you can use regexp grouping as well (I found that very useful):

SELECT REGEXP_REPLACE("stackoverflow", "(stack)(over)(flow)", '\\2 - \\1 - \\3')


over - stack - flow duplicate entry during packageAllDebugClassesForMultiDex

Simple Remove Your Jar file from dependencies gardle.project as v7 and run your project

No line-break after a hyphen

Late to the party, but I think this is actually the most elegant. Use the WORD JOINER Unicode character &#8288; on either side of your hyphen, or em dash, or any character.

So, like so:


This will join the symbol on both ends to its neighbors (without adding a space) and prevent line breaking.

Getting Integer value from a String using javascript/jquery

For parseInt to work, your string should have only numerical data. Something like this:

 str1 = "123.00";
 str2 = "50.00";
 total = parseInt(str1)+parseInt(str2);

Can you split the string before you start processing them for a total?

How to solve WAMP and Skype conflict on Windows 7?


Uncheck the option :

Use port 80 and 443 as alternative....

Comprehensive beginner's virtualenv tutorial?

Virtualenv is a tool to create isolated Python environments.

Let's say you're working in 2 different projects, A and B. Project A is a web project and the team is using the following packages:

  • Python 2.8.x
  • Django 1.6.x

The project B is also a web project but your team is using:

  • Python 2.7.x
  • Django 1.4.x

The machine that you're working doesn't have any version of django, what should you do? Install django 1.4? django 1.6? If you install django 1.4 globally would be easy to point to django 1.6 to work in project A?

Virtualenv is your solution! You can create 2 different virtualenv's, one for project A and another for project B. Now, when you need to work in project A, just activate the virtualenv for project A, and vice-versa.

A better tip when using virtualenv is to install virtualenvwrapper to manage all the virtualenv's that you have, easily. It's a wrapper for creating, working, removing virtualenv's.

How do I delete from multiple tables using INNER JOIN in SQL server

To build upon John Gibb's answer, for deleting a set of data in two tables with a FK relationship:

--*** To delete from tblMain which JOINs to (has a FK of) tblReferredTo's PK  
--       i.e.  ON tblMain.Refer_FK = tblReferredTo.ID
--*** !!! If you're CERTAIN that no other rows anywhere also refer to the 
--      specific rows in tblReferredTo !!!

    --*** Keep the ID's from tblReferredTo when we DELETE from tblMain
    DECLARE @tblDeletedRefs TABLE ( ID INT );
    --*** DELETE from the referring table first
    DELETE FROM tblMain 
    OUTPUT DELETED.Refer_FK INTO @tblDeletedRefs  -- doesn't matter that this isn't DISTINCT, the following DELETE still works.
    WHERE ..... -- be careful if filtering, what if other rows 
                --   in tblMain (or elsewhere) also point to the tblReferredTo rows?

    --*** Now we can remove the referred to rows, even though tblMain no longer refers to them.
    DELETE tblReferredTo
    FROM   tblReferredTo INNER JOIN @tblDeletedRefs Removed  
            ON tblReferredTo.ID = Removed.ID;


java.util.Date to XMLGregorianCalendar

For those that might end up here looking for the opposite conversion (from XMLGregorianCalendar to Date):

XMLGregorianCalendar xcal = <assume this is initialized>;
java.util.Date dt = xcal.toGregorianCalendar().getTime();

How can I display just a portion of an image in HTML/CSS?

adjust the background-position to move background images in different positions of the div

div { 
       background-image: url('image url')
       background-position: 0 -250px; 

Find largest and smallest number in an array

Unless you really must implement your own solution, you can use std::minmax_element. This returns a pair of iterators, one to the smallest element and one to the largest.

#include <algorithm>

auto minmax = std::minmax_element(std::begin(values), std::end(values));

std::cout << "min element " << *(minmax.first) << "\n";
std::cout << "max element " << *(minmax.second) << "\n";

What is the proper way to comment functions in Python?

I would go a step further than just saying "use a docstring". Pick a documentation generation tool, such as pydoc or epydoc (I use epydoc in pyparsing), and use the markup syntax recognized by that tool. Run that tool often while you are doing your development, to identify holes in your documentation. In fact, you might even benefit from writing the docstrings for the members of a class before implementing the class.

Concatenate text files with Windows command line, dropping leading lines

In powershell:

Get-Content file1.txt | Out-File out.txt
Get-Content file2.txt | Select-Object -Skip 1 | Out-File -Append out.txt

Drop view if exists

Regarding the error

'CREATE VIEW' must be the first statement in a query batch.

Microsoft SQL Server has a quirky reqirement that CREATE VIEW be the only statement in a batch. This is also true of a few other statements, such as CREATE FUNCTION. It is not true of CREATE TABLE, so go figure …

The solution is to send your script to the server in small batches. One way to do this is to select a single statement and execute it. This is clearly inconvenient.

The more convenient solution is to get the client to send the script in small isolated batches.

The GO keyword is not strictly an SQL command, which is why you can’t end it with a semicolon like real SQL commands. Instead it is an instruction to the client to break the script at this point and to send the portion as a batch.

As a result, you end up writing something like:


None of the other database servers I have encountered (PostgreSQL, MySQL, Oracle, SQLite) have this quirk, so the requirement appears to be Microsoft Only.

How do you calculate the variance, median, and standard deviation in C++ or Java?

To calculate the mean, loop through the list/array of numbers, keeping track of the partial sums and the length. Then return the sum/length.

double sum = 0.0;
int length = 0;

for( double number : numbers ) {
    sum += number;

return sum/length;

Variance is calculated similarly. Standard deviation is simply the square root of the variance:

double stddev = Math.sqrt( variance );

Create patch or diff file from git repository and apply it to another different git repository

You can just use git diff to produce a unified diff suitable for git apply:

git diff tag1..tag2 > mypatch.patch

You can then apply the resulting patch with:

git apply mypatch.patch

What is the quickest way to HTTP GET in Python?

If you want a lower level API:

import http.client

conn = http.client.HTTPSConnection('')
conn.request('GET', '/')

resp = conn.getresponse()
content =


text = content.decode('utf-8')


Easiest way to convert int to string in C++

Using stringstream for number conversion is dangerous!

See where it tells that operator<< inserts formatted output.

Depending on your current locale an integer greater than 3 digits, could convert to a string of 4 digits, adding an extra thousands separator.

E.g., int = 1000 could be convertet to a string 1.001. This could make comparison operations not work at all.

So I would strongly recommend using the std::to_string way. It is easier and does what you expect.

Updated (see comments below):

C++17 provides std::to_chars as a higher-performance locale-independent alternative

What is the height of iPhone's onscreen keyboard?

I created this table which contains both the heights of iPhone and iPad keyboards, both for landscape and portrait mode, both with the toolbar on and off.

I even explained how you can use these dimensions in your code here.

Note that you should only use these dimensions if you need to know the keyboard's dimension before you layout the view. Otherwise the solutions from the other answers work better.

enter image description here

How to store(bitmap image) and retrieve image from sqlite database in android?

Setting Up the database

public class DatabaseHelper extends SQLiteOpenHelper {
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "database_name";

    // Table Names
    private static final String DB_TABLE = "table_image";

    // column names
    private static final String KEY_NAME = "image_name";
    private static final String KEY_IMAGE = "image_data";

    // Table create statement
    private static final String CREATE_TABLE_IMAGE = "CREATE TABLE " + DB_TABLE + "("+ 
                       KEY_NAME + " TEXT," + 
                       KEY_IMAGE + " BLOB);";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

    public void onCreate(SQLiteDatabase db) {

        // creating table

    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // on upgrade drop older tables
        db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE);

        // create new table

Insert in the Database:

public void addEntry( String name, byte[] image) throws SQLiteException{
    SQLiteDatabase database = this.getWritableDatabase();
    ContentValues cv = new  ContentValues();
    cv.put(KEY_NAME,    name);
    cv.put(KEY_IMAGE,   image);
    database.insert( DB_TABLE, null, cv );

Retrieving data:

 byte[] image = cursor.getBlob(1);


  1. Before inserting into database, you need to convert your Bitmap image into byte array first then apply it using database query.
  2. When retrieving from database, you certainly have a byte array of image, what you need to do is to convert byte array back to original image. So, you have to make use of BitmapFactory to decode.

Below is an Utility class which I hope could help you:

public class DbBitmapUtility {

    // convert from bitmap to byte array
    public static byte[] getBytes(Bitmap bitmap) {
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(CompressFormat.PNG, 0, stream);
        return stream.toByteArray();

    // convert from byte array to bitmap
    public static Bitmap getImage(byte[] image) {
        return BitmapFactory.decodeByteArray(image, 0, image.length);

Further reading
If you are not familiar how to insert and retrieve into a database, go through this tutorial.

Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code

For me the reason was while changing name of app I added a single quote ' in name. I tried different solution and ran into different errors, but at last, while renaming app, I did not include ' single quote and it solved the problem.

How to check if a string is a valid JSON string in JavaScript without using Try/Catch

For people who like the .Net convention of "try" functions that return a boolean and handle a byref param containing the result. If you don't need the out parameter you can omit it and just use the return value.


  var obj1 = {};
  var bool1 = '{"h":"happy"}'.tryParse(obj1); // false
  var obj2 = {};
  var bool2 = '2114509 GOODLUCKBUDDY 315852'.tryParse(obj2);  // false

  var obj3 = {};
  if('{"house_number":"1","road":"Mauchly","city":"Irvine","county":"Orange County","state":"California","postcode":"92618","country":"United States of America","country_code":"us"}'.tryParse(obj3))


String.prototype.tryParse = function(jsonObject) {
  jsonObject = jsonObject || {};
  try {
    if(!/^[\[{]/.test(this) || !/[}\]]$/.test(this)) // begin / end with [] or {}
      return false; // avoid error handling for strings that obviously aren't json
    var json = JSON.parse(this);
    if(typeof json === 'object'){
      return true;
  } catch (e) {
    return false;


Object.defineProperty(Object.prototype, 'merge', {
  value: function(mergeObj){
    for (var propertyName in mergeObj) {
      if (mergeObj.hasOwnProperty(propertyName)) {
        this[propertyName] = mergeObj[propertyName];
    return this;
  enumerable: false, // this is actually the default

How to delete last character from a string using jQuery?

This page comes first when you search on Google "remove last character jquery"

Although all previous answers are correct, somehow did not helped me to find what I wanted in a quick and easy way.

I feel something is missing. Apologies if i'm duplicating


  var text = $(this).html();
  text = text.substring(0, text.length-1);


  var text = $(this).html();
  text = text.slice(0,-1);

Groovy - Convert object to JSON string

You can use JsonBuilder for that.

Example Code:

import groovy.json.JsonBuilder

class Person {
    String name
    String address

def o = new Person( name: 'John Doe', address: 'Texas' )

println new JsonBuilder( o ).toPrettyString()

cannot resolve symbol javafx.application in IntelliJ Idea IDE

You might have a lower project language level than your JDK.

Check if: "Projeckt structure/project/Project-> language level" is lower than your JDK. I had the same problem with JDK 9 and the language level was per default set to 6.

I set the Project Language Level to 9 and everything worked fine after that.

You might have the same issue.

how to configuring a xampp web server for different root directory

If you are running xampp on linux based image, to change root directory open:


Change default document root: DocumentRoot "/opt/lampp/htdocs" and <Directory "/opt/lampp/htdocs"

to your folder DocumentRoot "/opt/lampp/htdocs/myFolder" and <Directory "/opt/lampp/htdocs/myFolder">

"Port 4200 is already in use" when running the ng serve command

When you use Ctrl+Z, you are going to suspend a running task but not to kill it. You can later use command fg to resume the task. If you want to quit ng serve, you should use Ctrl+C instead, in which will also release the 4200 port.

Keyboard shortcut to comment lines in Sublime Text 3

In Windows use ctrl + shift + : to comment for Python.

C# "internal" access modifier when doing unit testing

In .NET Core 2.2, add this line to your Program.cs:

using ...
using System.Runtime.CompilerServices;

[assembly: InternalsVisibleTo("MyAssembly.Unit.Tests")]


SQL MAX of multiple columns?

From SQL Server 2012 we can use IIF.

 DECLARE @Date1 DATE='2014-07-03';
 DECLARE @Date2 DATE='2014-07-04';
 DECLARE @Date3 DATE='2014-07-05';

 SELECT IIF(@Date1>@Date2,
        IIF(@Date2>@Date3,@Date2,@Date3)) AS MostRecentDate

Convert multidimensional array into single array

 $singleArray = array();

    foreach ($multiDimensionalArray as $key => $value){
        $singleArray[$key] = $value['plan'];

this is best way to create a array from multiDimensionalArray array.


How do I remove my IntelliJ license in 2019.3?

in linux/ubuntu you can do, run following commands

cd ~/.config/JetBrains/PyCharm2020.1
rm eval/PyCharm201.evaluation.key
sed -i '/evlsprt/d' options/other.xml
cd ~/.java/.userPrefs/jetbrains
rm -rf pycharm*

jQuery show for 5 seconds then hide

You can use the below effect to animate, you can change the values as per your requirements

$("#myElem").fadeIn('slow').animate({opacity: 1.0}, 1500).effect("pulsate", { times: 2 }, 800).fadeOut('slow'); 

Android SQLite Example

The following Links my help you

1. Android Sqlite Database

2. Tutorial 1

Database Helper Class:

A helper class to manage database creation and version management.

You create a subclass implementing onCreate(SQLiteDatabase), onUpgrade(SQLiteDatabase, int, int) and optionally onOpen(SQLiteDatabase), and this class takes care of opening the database if it exists, creating it if it does not, and upgrading it as necessary. Transactions are used to make sure the database is always in a sensible state.

This class makes it easy for ContentProvider implementations to defer opening and upgrading the database until first use, to avoid blocking application startup with long-running database upgrades.

You need more refer this link Sqlite Helper

What does MVW stand for?

Having said, I'd rather see developers build kick-ass apps that are well-designed and follow separation of concerns, than see them waste time arguing about MV* nonsense. And for this reason, I hereby declare AngularJS to be MVW framework - Model-View-Whatever. Where Whatever stands for "whatever works for you".

Credits : AngularJS Post - Igor Minar

Spin or rotate an image on hover

It's very simple.

  1. You add an image.
  2. You create a css property to this image.

    img { transition: all 0.3s ease-in-out 0s; }
  3. You add an animation like that:

        cursor: default;
        transform: rotate(360deg);
        transition: all 0.3s ease-in-out 0s;
    } the trustAnchors parameter must be non-empty on Linux, or why is the default truststore empty

My solution on Windows was to either run console window as Administrator or change the environment variable MAVEN_OPTS to use a hardcoded path to trust.jks (e.g. 'C:\Users\oddros') instead of '%USERPROFILE%'. My MAVEN_OPTS now looks like this:\Users\oddros\trust.jks

UITapGestureRecognizer - single tap and double tap

In reference to @stanley's comment -

Don't try and use tap gestures to row selections to work in UITableView as it already has full tap handling....

But you must set 'Cancels Touches in View' to 'NO' on your single tap gesture recognizers or it will never get the tap events.

how to destroy bootstrap modal window completely?

If modal shadow remains darker and not going for showing more than one modal then this will be helpful


How do I run a program with commandline arguments using GDB within a Bash script?

gdb has --init-command <somefile> where somefile has a list of gdb commands to run, I use this to have //GDB comments in my code, then `

echo "file ./a.out" > run
grep -nrIH "//GDB"|
    sed "s/\(^[^:]\+:[^:]\+\):.*$/\1/g" |
    awk '{print "b" " " $1}'|
    grep -v $(echo $0|sed "s/.*\///g") >> run
gdb --init-command ./run -ex=r

as a script, which puts the command to load the debug symbols, and then generates a list of break commands to put a break point for each //GDB comment, and starts it running

Flexbox: center horizontally and vertically

I think you want something like the following.

html, body {_x000D_
    height: 100%;_x000D_
body {_x000D_
    margin: 0;_x000D_
.flex-container {_x000D_
    height: 100%;_x000D_
    padding: 0;_x000D_
    margin: 0;_x000D_
    display: -webkit-box;_x000D_
    display: -moz-box;_x000D_
    display: -ms-flexbox;_x000D_
    display: -webkit-flex;_x000D_
    display: flex;_x000D_
    align-items: center;_x000D_
    justify-content: center;_x000D_
.row {_x000D_
    width: auto;_x000D_
    border: 1px solid blue;_x000D_
.flex-item {_x000D_
    background-color: tomato;_x000D_
    padding: 5px;_x000D_
    width: 20px;_x000D_
    height: 20px;_x000D_
    margin: 10px;_x000D_
    line-height: 20px;_x000D_
    color: white;_x000D_
    font-weight: bold;_x000D_
    font-size: 2em;_x000D_
    text-align: center;_x000D_
<div class="flex-container">_x000D_
    <div class="row"> _x000D_
        <div class="flex-item">1</div>_x000D_
        <div class="flex-item">2</div>_x000D_
        <div class="flex-item">3</div>_x000D_
        <div class="flex-item">4</div>_x000D_

See demo at:

Your .flex-item elements should be block level (div instead of span) if you want the height and top/bottom padding to work properly.

Also, on .row, set the width to auto instead of 100%.

Your .flex-container properties are fine.

If you want the .row to be centered vertically in the view port, assign 100% height to html and body, and also zero out the body margins.

Note that .flex-container needs a height to see the vertical alignment effect, otherwise, the container computes the minimum height needed to enclose the content, which is less than the view port height in this example.

The flex-flow, flex-direction, flex-wrap properties could have made this design easier to implement. I think that the .row container is not needed unless you want to add some styling around the elements (background image, borders and so on).

A useful resource is:

How do I remove link underlining in my HTML email?

Windows Mail seemed to outright ignore inline text-decoration tag but what fixed it for me was by adding this to the head:

<!--[if (mso)|(mso 16)]>
<style type="text/css">
    body, table, td, a, span { font-family: Arial, Helvetica, sans-serif !important; }
    a {text-decoration: none;}

Replace text in HTML page with jQuery

The html replace idea is good, but if done to the document.body, the page will blink and ads will disappear.

My solution:
$("*:contains('purrfect')").each(function() { var replaced = $(this).html().replace(/purrfect/g, "purrfect"); $(this).html(replaced); });

Test credit card numbers for use with PayPal sandbox

It turns out, after messing around with all of the settings in the test business account, that one (or more) of the fraud related settings in the payment receiving preferences / security settings screens were causing the test payments to fail (without any useful error).

Use PHP to create, edit and delete crontab jobs?

Instead of crontab you could also use google's app engine task queue. It has a generous free quota, is fast, scalable, modifiable.

Stopping a JavaScript function when a certain condition is met

Try using a return statement. It works best. It stops the function when the condition is met.

function anything() {
    var get = document.getElementsByClassName("text ").value;
    if (get == null) {
        alert("Please put in your name");


    var random = Math.floor(Math.random() * 100) + 1;

C# How to determine if a number is a multiple of another?

bool isMultiple = a % b == 0;

This will be true if a is a multiple of b

What is the most efficient way to check if a value exists in a NumPy array?

The most obvious to me would be:

np.any(my_array[:, 0] == value)

How to Alter a table for Identity Specification is identity SQL Server

You can't alter the existing columns for identity.

You have 2 options,

Create a new table with identity & drop the existing table

Create a new column with identity & drop the existing column

Approach 1. (New table) Here you can retain the existing data values on the newly created identity column.

CREATE TABLE dbo.Tmp_Names
      Id int NOT NULL
             IDENTITY(1, 1),
      Name varchar(50) NULL


            FROM    dbo.Names ) 
    INSERT  INTO dbo.Tmp_Names ( Id, Name )
            SELECT  Id,
            FROM    dbo.Names TABLOCKX


DROP TABLE dbo.Names

Exec sp_rename 'Tmp_Names', 'Names'

Approach 2 (New column) You can’t retain the existing data values on the newly created identity column, The identity column will hold the sequence of number.

Alter Table Names
Add Id_new Int Identity(1, 1)

Alter Table Names Drop Column ID

Exec sp_rename 'Names.Id_new', 'ID', 'Column'

See the following Microsoft SQL Server Forum post for more details:

How to insert a timestamp in Oracle?

into tablename (timestamp_value)
values (TO_TIMESTAMP(:ts_val, 'YYYY-MM-DD HH24:MI:SS'));

if you want the current time stamp to be inserted then:

into tablename (timestamp_value)

Field 'id' doesn't have a default value?

As a developer it is highly recommended to use STRICT mode because it will allow you to see issues/errors/warnings that may come about instead of just working around it by turning off strict mode. It's also better practice.

Strict mode is a great tool to see messy, sloppy code.

PUT and POST getting 405 Method Not Allowed Error for Restful Web Services

The problem is that POST method is forbidden for Nginx server's static files requests. Here is the workaround:

# Pass 405 as 200 for requested address:

server {
listen       80;
server_name  localhost;

location / {
    root   html;
    index  index.html index.htm;

error_page  404     /404.html;
error_page  403     /403.html;

error_page  405     =200 $uri;

If using proxy:

# If Nginx is like proxy for Apache:

error_page 405 =200 @405; 

location @405 { 
    root /htdocs; 
    proxy_pass http://localhost:8080; 

If using FastCGI:

location ~\.php(.*) {
fastcgi_split_path_info ^(.+\.php)(.*)$;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param PATH_TRANSLATED $document_root$fastcgi_path_info;
include /etc/nginx/fastcgi_params;

Browsers usually use GET, so you can use online tools like ApiTester to test your requests.


How to iterate for loop in reverse order in swift?

If one is wanting to iterate through an array (Array or more generally any SequenceType) in reverse. You have a few additional options.

First you can reverse() the array and loop through it as normal. However I prefer to use enumerate() much of the time since it outputs a tuple containing the object and it's index.

The one thing to note here is that it is important to call these in the right order:

for (index, element) in array.enumerate().reverse()

yields indexes in descending order (which is what I generally expect). whereas:

for (index, element) in array.reverse().enumerate() (which is a closer match to NSArray's reverseEnumerator)

walks the array backward but outputs ascending indexes.

Iterating over Typescript Map

Just a simple explanation to use it in an HTML document.

If you have a Map of types (key, array) then you initialise the array this way:

public cityShop: Map<string, Shop[]> = new Map();

And to iterate over it, you create an array from key values.

Just use it as an array as in:

keys = Array.from(this.cityShop.keys());

Then, in HTML, you can use:

*ngFor="let key of keys"

Inside this loop, you just get the array value with:



Check if a String contains a special character

//this is updated version of code that i posted /* The isValidName Method will check whether the name passed as argument should not contain- 1.null value or space 2.any special character 3.Digits (0-9) Explanation--- Here str2 is String array variable which stores the the splited string of name that is passed as argument The count variable will count the number of special character occurs The method will return true if it satisfy all the condition */

public boolean isValidName(String name)
    String specialCharacters=" !#$%&'()*+,-./:;<=>?@[]^_`{|}~0123456789";
    String str2[]=name.split("");
    int count=0;
    for (int i=0;i<str2.length;i++)
        if (specialCharacters.contains(str2[i]))

    if (name!=null && count==0 )
        return true;
        return false;

How to create an empty array in Swift?

Initiating an array with a predefined count:

Array(repeating: 0, count: 10)

I often use this for mapping statements where I need a specified number of mock objects. For example,

let myObjects: [MyObject] = Array(repeating: 0, count: 10).map { _ in return MyObject() }

How can I add new item to the String array?

String a []=new String[1];

  a[0].add("kk" );

Try this one...


You have wrong database design and you should take a time to read something about database normalization (wikipedia / stackoverflow).

I assume your table looks somewhat like this

| group_id | user_ids | name   |
| 1        | 1,4,6    | group1 |
| 2        | 4,5,1    | group2 |    

so in your table of user groups, each row represents one group and in user_ids column you have set of user ids assigned to that group.

Normalized version of this table would look like this

| id       | name   |
| 1        | group1 |
| 2        | group2 |    

| group_id | user_id |
| 1        | 1       |
| 1        | 4       |
| 1        | 6       |
| 2        | 4       |
| ...      

Then you can easily select all users with assigned group, or all users in group, or all groups of user, or whatever you can think of. Also, your sql query will work:

/* Your query to select assignments */
SELECT * FROM `group_user_assignment` WHERE user_id IN (1,2,3,4);

/* Select only some users */
SELECT * FROM `group_user_assignment` t1
JOIN `group` t2 ON = t1.group_id
WHERE user_id IN (1,4);

/* Select all groups of user */
SELECT * FROM `group_user_assignment` t1
JOIN `group` t2 ON = t1.group_id
WHERE t1.`user_id` = 1;

/* Select all users of group */
SELECT * FROM `group_user_assignment` t1
JOIN `group` t2 ON = t1.group_id
WHERE t1.`group_id` = 1;

/* Count number of groups user is in */
SELECT COUNT(*) AS `groups_count` FROM `group_user_assignment` WHERE `user_id` = 1;

/* Count number of users in group */
SELECT COUNT(*) AS `users_count` FROM `group_user_assignment` WHERE `group_id` = 1;

This way it will be also easier to update database, when you would like to add new assignment, you just simply insert new row in group_user_assignment, when you want to remove assignment you just delete row in group_user_assignment.

In your database design, to update assignments, you would have to get your assignment set from database, process it and update and then write back to database.

Here is sqlFiddle to play with.

How do I measure request and response times at once using cURL?

curl -v --trace-time This must be done in verbose mode

OpenCV - DLL missing, but it's not?

You just need to add the folder of the needed dll file (or files) to your system "Environment Variables" in "Path". Your problem will 100% be resolved. I had this problem too.

Java error: Comparison method violates its general contract

I had to sort on several criterion (date, and, if same date; other things...). What was working on Eclipse with an older version of Java, did not worked any more on Android : comparison method violates contract ...

After reading on StackOverflow, I wrote a separate function that I called from compare() if the dates are the same. This function calculates the priority, according to the criteria, and returns -1, 0, or 1 to compare(). It seems to work now.

What is the use of "assert"?

My short explanation is:

  • assert raises AssertionError if expression is false, otherwise just continues the code, and if there's a comma whatever it is it will be AssertionError: whatever after comma, and to code is like: raise AssertionError(whatever after comma)

A related tutorial about this:

How to bind event listener for rendered elements in Angular 2?

HostListener should be the proper way to bind event into your component:

  selector: 'your-element'

export class YourElement {
  @HostListener('click', ['$event']) onClick(event) {
     console.log('component is clicked');

When using a Settings.settings file in .NET, where is the config actually stored?

It depends on whether the setting you have chosen is at "User" scope or "Application" scope.

User scope

User scope settings are stored in

C:\Documents and Settings\ username \Local Settings\Application Data\ ApplicationName

You can read/write them at runtime.

For Vista and Windows 7, folder is

C:\Users\ username \AppData\Local\ ApplicationName


C:\Users\ username \AppData\Roaming\ ApplicationName

Application scope

Application scope settings are saved in AppName.exe.config and they are readonly at runtime.

Where can I find a NuGet package for upgrading to System.Web.Http v5.0.0.0?

I have several projects in a solution. For some of the projects, I previously added the references manually. When I used NuGet to update the WebAPI package, those references were not updated automatically.

I found out that I can either manually update those reference so they point to the v5 DLL inside the Packages folder of my solution or do the following.

  1. Go to the "Manage NuGet Packages"
  2. Select the Installed Package "Microsoft ASP.NET Web API 2.1"
  3. Click Manage and check the projects that I manually added before.

shift a std_logic_vector of n bit to right or left

add_Pbl <= to_stdlogicvector(to_bitvector(dato_cu(25 downto 2)) sll 1);
add_Pbl is a std_logic_vector of 24 bit
dato_cu is a std_logic_vector of 32 bit

First, you need to convert the std_logic_vector with to_bitvector() function because sll statement works with logic 1 and 0 bits.

Remove char at specific index - python

def remove_char(input_string, index):
    first_part = input_string[:index]
    second_part - input_string[index+1:]
    return first_part + second_part

s = 'aababc'
index = 1

zero-based indexing using a form to insert data into an sql server table

Simple, make a simple asp page with the designer (just for the beginning) Lets say the body is something like this:

    <form id="form1" runat="server">
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <br />
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="Button" />

Great, now every asp object IS an object. So you can access it in the asp's CS code. The asp's CS code is triggered by events (mostly). The class will probably inherit from System.Web.UI.Page

If you go to the cs file of the asp page, you'll see a protected void Page_Load(object sender, EventArgs e) ... That's the load event, you can use that to populate data into your objects when the page loads.

Now, go to the button in your designer (Button1) and look at its properties, you can design it, or add events from there. Just change to the events view, and create a method for the event.

The button is a web control Button Add a Click event to the button call it Button1Click:

void Button1Click(Object sender,EventArgs e) { }

Now when you click the button, this method will be called. Because ASP is object oriented, you can think of the page as the actual class, and the objects will hold the actual current data.

So if for example you want to access the text in TextBox1 you just need to call that object in the C# code:

String firstBox = TextBox1.Text;

In the same way you can populate the objects when event occur.

Now that you have the data the user posted in the textboxes , you can use regular C# SQL connections to add the data to your database.

How do I vertically align text in a paragraph?

If you use Bootstrap, try to assign margin-bottom 0 to the paragraph and after assign the property align-items-center to container, for example, like this:

<div class="row align-items-center">
     <p class="col-sm-1 mb-0">

Bootstrap by default assign a calculate margin bottom, so mb-0 disabled this.

I hope it helps

How to set width of a p:column in a p:dataTable in PrimeFaces 3.0?

I don't know what browser you're using, but according to, nth-child and nth-last-child do now work on MSIE 8. I don't know about 9. will give you more info.

Sorting a list with stream.sorted() in Java

This is not like Collections.sort() where the parameter reference gets sorted. In this case you just get a sorted stream that you need to collect and assign to another variable eventually:

List result =, o2)->o1.getItem().getValue().

You've just missed to assign the result

Storing money in a decimal column - what precision and scale?

Sometimes you will need to go to less than a cent and there are international currencies that use very large demoniations. For example, you might charge your customers 0.088 cents per transaction. In my Oracle database the columns are defined as NUMBER(20,4)

Delaying a jquery script until everything else has loaded

From here:

// Add jQuery 
var GM_JQ = document.createElement('script'); 
GM_JQ.src = '';
GM_JQ.type = 'text/javascript'; 

// Check if jQuery's loaded 
function GM_wait() 
    if(typeof unsafeWindow.jQuery == 'undefined') 
        $ = unsafeWindow.jQuery; 


// All your GM code must be inside this function 
function letsJQuery() 
    // Do your jQuery stuff in here    

This will wait until jQuery is loaded to use it, but you can use the same concept, setting variables in your other scripts (or checking them if they're not your script) to wait until they're loaded to use them.

For example, on my site, I use this for asynchronous JS loading and waiting until they're finished before doing anything with them using jQuery:

<script type="text/javascript" language="JavaScript"> 
    function js(url){
        s = document.createElement("script");
        s.type = "text/javascript";
        s.src = url;


    function JS_wait() {
        if (typeof $.cookie == 'undefined' || // set in jquery.cookie-min.js
            typeof getLastViewedAnchor == 'undefined' || // set in application-min.js
            typeof getLastViewedArchive == 'undefined' || // set in application-min.js 
            typeof getAntiSpamValue == 'undefined') // set in application-min.js
            window.setTimeout(JS_wait, 100); 

    function JS_ready() {
        // snipped


How to go back last page

You can implement routerOnActivate() method on your route class, it will provide information about previous route.

routerOnActivate(nextInstruction: ComponentInstruction, prevInstruction: ComponentInstruction) : any

Then you can use router.navigateByUrl() and pass data generated from ComponentInstruction. For example:


React passing parameter via onclick event using ES6 syntax

Use Arrow function like this:

<button onClick={()=>{this.handleRemove(id)}}></button>

Git with SSH on Windows

I fought with this problem for a few hours before stumbling on the obvious answer. The problem I had was I was using different ssh implementations between when I generated my keys and when I used git.

I used ssh-keygen from the command prompt to generate my keys and but when I tried "git clone ssh://..." I got the same results as you, a prompt for the password and the message "fatal: The remote end hung up unexpectedly".

Determine which ssh windows is using by executing the Windows "where" command.

C:\where ssh
C:\Program Files (x86)\Git\bin\ssh.exe

The second line tells you which exact program will be executed.

Next you need to determine which ssh that git is using. Find this by:

C:\set GIT_SSH
GIT_SSH=C:\Program Files\TortoiseSVN\bin\TortoisePlink.exe

And now you see the problem.

To correct this simply execute:

C:\set GIT_SSH=C:\Program Files (x86)\Git\bin\ssh.exe

To check if changes are applied:

C:\set GIT_SSH
GIT_SSH=C:\Program Files (x86)\Git\bin\ssh.exe

Now git will be able to use the keys that you generated earlier.

This fix is so far only for the current window. To fix it completely you need to change your environment variable.

  1. Open Windows explorer
  2. Right-click Computer and select Properties
  3. Click Advanced System Settings link on the left
  4. Click the Environment Variables... button
  5. In the system variables section select the GIT_SSH variable and press the Edit... button
  6. Update the variable value.
  7. Press OK to close all windows

Now any future command windows you open will have the correct settings.

Hope this helps.

How can I read inputs as numbers?

While in your example, int(input(...)) does the trick in any case, python-future's builtins.input is worth consideration since that makes sure your code works for both Python 2 and 3 and disables Python2's default behaviour of input trying to be "clever" about the input data type (builtins.input basically just behaves like raw_input).

Allow only pdf, doc, docx format for file upload?

Try this

 $('#resume_link').click(function() {
        var ext = $('#resume').val().split(".").pop().toLowerCase();
        if($.inArray(ext, ["doc","pdf",'docx']) == -1) {
            // false
            // true

Hope it will help

How to use count and group by at the same select statement

You can use DISTINCT inside the COUNT like what milkovsky said

in my case:

select COUNT(distinct user_id) from answers_votes where answer_id in (694,695);

This will pull the count of answer votes considered the same user_id as one count

How to check if an array element exists?

You can use isset() for this very thing.

$myArr = array("Name" => "Jonathan");
print (isset($myArr["Name"])) ? "Exists" : "Doesn't Exist" ;

Multiple WHERE clause in Linq


The LINQ translator is smart enough to execute:

.Where(r => r.UserName !="XXXX" && r.UsernName !="YYYY")

I've test this in LinqPad ==> YES, Linq translator is smart enough :))

How to examine processes in OS X's Terminal?

Try ps -ef. man ps will give you all the options.

 -A      Display information about other users' processes, including those without controlling terminals.

 -e      Identical to -A.

 -f      Display the uid, pid, parent pid, recent CPU usage, process start time, controlling tty, elapsed CPU usage, and the associated command.  If the -u option is also used, display
         the user name rather then the numeric uid.  When -o or -O is used to add to the display following -f, the command field is not truncated as severely as it is in other formats.

How to import a CSS file in a React Component

You can also use the required module.

const React = require('react');