Programs & Examples On #Concurrent mark sweep

Concurrent-mark-sweep is a garbage collection algorithm, known for its use on the Java Virtual Machine, which can reduce stop-the-world times on machines with limited resources.

<img>: Unsafe value used in a resource URL context

Angular treats all values as untrusted by default. When a value is inserted into the DOM from a template, via property, attribute, style, class binding, or interpolation, Angular sanitizes and escapes untrusted values.

So if you are manipulating DOM directly and inserting content it, you need to sanitize it otherwise Angular will through errors.

I have created the pipe SanitizeUrlPipe for this

import { PipeTransform, Pipe } from "@angular/core";
import { DomSanitizer, SafeHtml } from "@angular/platform-browser";

@Pipe({
    name: "sanitizeUrl"
})
export class SanitizeUrlPipe implements PipeTransform {

    constructor(private _sanitizer: DomSanitizer) { }

    transform(v: string): SafeHtml {
        return this._sanitizer.bypassSecurityTrustResourceUrl(v);
    }
}

and this is how you can use

<iframe [src]="url | sanitizeUrl" width="100%" height="500px"></iframe>

If you want to add HTML, then SanitizeHtmlPipe can help

import { PipeTransform, Pipe } from "@angular/core";
import { DomSanitizer, SafeHtml } from "@angular/platform-browser";

@Pipe({
    name: "sanitizeHtml"
})
export class SanitizeHtmlPipe implements PipeTransform {

    constructor(private _sanitizer: DomSanitizer) { }

    transform(v: string): SafeHtml {
        return this._sanitizer.bypassSecurityTrustHtml(v);
    }
}

Read more about angular security here.

Print "\n" or newline characters as part of the output on terminal

If you're in control of the string, you could also use a 'Raw' string type:

>>> string = r"abcd\n"
>>> print(string)
abcd\n

getting file size in javascript

function findSize() {
    var fileInput =  document.getElementById("fUpload");
    try{
        alert(fileInput.files[0].size); // Size returned in bytes.
    }catch(e){
        var objFSO = new ActiveXObject("Scripting.FileSystemObject");
        var e = objFSO.getFile( fileInput.value);
        var fileSize = e.size;
        alert(fileSize);    
    }
}

How can I display the current branch and folder path in terminal?

From Mac OS Catalina .bash_profile is replaced with .zprofile

Step 1: Create a .zprofile

touch .zprofile

Step 2:

nano .zprofile

type below line in this

source ~/.bash_profile

and save(ctrl+o return ctrl+x)

Step 3: Restart your terminal

To Add Git Branch Name Now you can add below lines in .bash_profile

    parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}

export PS1="\u@\h \[\033[32m\]\w - \$(parse_git_branch)\[\033[00m\] $ "

Restart your terminal this will work.

Note: Even you can rename .bash_profile to .zprofile that also works.

Dynamically Changing log4j log level

You can use following code snippet

((ch.qos.logback.classic.Logger)LoggerFactory.getLogger(packageName)).setLevel(ch.qos.logback.classic.Level.toLevel(logLevel));

How do I make WRAP_CONTENT work on a RecyclerView

I have not worked on my answer but the way I know it StaggridLayoutManager with no. of grid 1 can solve your problem as StaggridLayout will automatically adjust its height and width on the size of the content. if it works dont forget to check it as a right answer.Cheers..

Links in <select> dropdown options

Maybe this will help:

<select onchange="location = this.value;">
 <option value="home.html">Home</option>
 <option value="contact.html">Contact</option>
 <option value="about.html">About</option>
</select>

Could not find com.google.android.gms:play-services:3.1.59 3.2.25 4.0.30 4.1.32 4.2.40 4.2.42 4.3.23 4.4.52 5.0.77 5.0.89 5.2.08 6.1.11 6.1.71 6.5.87

I've been strugglin with this problem for hours till found this post. Just like @ligi said, some people have two SDK folders (Android Studio, which is bundled and Eclipse). The problem is that it doesn't matter if you downloaded the Google Play Services library on both SDK folders, your ANDROID_HOME enviroment variable must be pointing to the SDK folder used by the Android Studio.

SDK Folder A  (Used on Eclipse)
SDK Folder B  (Used on AS)

ANDROID_HOME=<path to SDK Folder B>

After change the path of this variable the error was gone.

Difference between abstract class and interface in Python

For completeness, we should mention PEP3119 where ABC was introduced and compared with interfaces, and original Talin's comment.

The abstract class is not perfect interface:

  • belongs to the inheritance hierarchy
  • is mutable

But if you consider writing it your own way:

def some_function(self):
     raise NotImplementedError()

interface = type(
    'your_interface', (object,),
    {'extra_func': some_function,
     '__slots__': ['extra_func', ...]
     ...
     '__instancecheck__': your_instance_checker,
     '__subclasscheck__': your_subclass_checker
     ...
    }
)

ok, rather as a class
or as a metaclass
and fighting with python to achieve the immutable object
and doing refactoring
...

you'll quite fast realize that you're inventing the wheel to eventually achieve abc.ABCMeta

abc.ABCMeta was proposed as a useful addition of the missing interface functionality, and that's fair enough in a language like python.

Certainly, it was able to be enhanced better whilst writing version 3, and adding new syntax and immutable interface concept ...

Conclusion:

The abc.ABCMeta IS "pythonic" interface in python

How get permission for camera in android.(Specifically Marshmallow)

This works for me, the source is here

int MY_PERMISSIONS_REQUEST_CAMERA=0;
// Here, this is the current activity
if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
{
     if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA))
     {

     }
     else
     {
          ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA}, MY_PERMISSIONS_REQUEST_CAMERA );
          // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
          // app-defined int constant. The callback method gets the
          // result of the request.
      }
}

Java - Check if input is a positive integer, negative integer, natural number and so on.

If you really have to avoid operators then use Math.signum()

Returns the signum function of the argument; zero if the argument is zero, 1.0 if the argument is greater than zero, -1.0 if the argument is less than zero.

EDIT : As per the comments, this works for only double and float values. For integer values you can use the method:

Integer.signum(int i)

Set JavaScript variable = null, or leave undefined?

I usually set it to whatever I expect to be returned from the function.

If a string, than i will set it to an empty string ='', same for object ={} and array=[], integers = 0.

using this method saves me the need to check for null / undefined. my function will know how to handle string/array/object regardless of the result.

How to download Visual Studio Community Edition 2015 (not 2017)

You can use these links to download Visual Studio 2015

Community Edition:

And for anyone in the future who might be looking for the other editions here are the links for them as well:

Professional Edition:

Enterprise Edition:

Keras, How to get the output of each layer?

From: https://github.com/philipperemy/keras-visualize-activations/blob/master/read_activations.py

import keras.backend as K

def get_activations(model, model_inputs, print_shape_only=False, layer_name=None):
    print('----- activations -----')
    activations = []
    inp = model.input

    model_multi_inputs_cond = True
    if not isinstance(inp, list):
        # only one input! let's wrap it in a list.
        inp = [inp]
        model_multi_inputs_cond = False

    outputs = [layer.output for layer in model.layers if
               layer.name == layer_name or layer_name is None]  # all layer outputs

    funcs = [K.function(inp + [K.learning_phase()], [out]) for out in outputs]  # evaluation functions

    if model_multi_inputs_cond:
        list_inputs = []
        list_inputs.extend(model_inputs)
        list_inputs.append(0.)
    else:
        list_inputs = [model_inputs, 0.]

    # Learning phase. 0 = Test mode (no dropout or batch normalization)
    # layer_outputs = [func([model_inputs, 0.])[0] for func in funcs]
    layer_outputs = [func(list_inputs)[0] for func in funcs]
    for layer_activations in layer_outputs:
        activations.append(layer_activations)
        if print_shape_only:
            print(layer_activations.shape)
        else:
            print(layer_activations)
    return activations

How to delete specific columns with VBA?

You say you want to delete any column with the title "Percent Margin of Error" so let's try to make this dynamic instead of naming columns directly.

Sub deleteCol()

On Error Resume Next

Dim wbCurrent As Workbook
Dim wsCurrent As Worksheet
Dim nLastCol, i As Integer

Set wbCurrent = ActiveWorkbook
Set wsCurrent = wbCurrent.ActiveSheet
'This next variable will get the column number of the very last column that has data in it, so we can use it in a loop later
nLastCol = wsCurrent.Cells.Find("*", LookIn:=xlValues, SearchOrder:=xlByColumns, SearchDirection:=xlPrevious).Column

'This loop will go through each column header and delete the column if the header contains "Percent Margin of Error"
For i = nLastCol To 1 Step -1
    If InStr(1, wsCurrent.Cells(1, i).Value, "Percent Margin of Error", vbTextCompare) > 0 Then
        wsCurrent.Columns(i).Delete Shift:=xlShiftToLeft
    End If
Next i

End Sub

With this you won't need to worry about where you data is pasted/imported to, as long as the column headers are in the first row.

EDIT: And if your headers aren't in the first row, it would be a really simple change. In this part of the code: If InStr(1, wsCurrent.Cells(1, i).Value, "Percent Margin of Error", vbTextCompare) change the "1" in Cells(1, i) to whatever row your headers are in.

EDIT 2: Changed the For section of the code to account for completely empty columns.

How do I install soap extension?

I had the same problem, there was no extension=php_soap.dll in my php.ini But this was because I had copied the php.ini from a old and previous php version (not a good idea). I found the dll in the ext directory so I just could put it myself into the php.ini extension=php_soap.dll After Apache restart all worked with soap :)

How to check whether particular port is open or closed on UNIX?

Try (maybe as root)

lsof -i -P

and grep the output for the port you are looking for.

For example to check for port 80 do

lsof -i -P | grep :80

How can I overwrite file contents with new content in PHP?

MY PREFERRED METHOD is using fopen,fwrite and fclose [it will cost less CPU]

$f=fopen('myfile.txt','w');
fwrite($f,'new content');
fclose($f);

Warning for those using file_put_contents

It'll affect a lot in performance, for example [on the same class/situation] file_get_contents too: if you have a BIG FILE, it'll read the whole content in one shot and that operation could take a long waiting time

Convert a list to a string in C#

The .ToString() method for reference types usually resolves back to System.Object.ToString() unless you override it in a derived type (possibly using extension methods for the built-in types). The default behavior for this method is to output the name of the type on which it's called. So what you're seeing is expected behavior.

You could try something like string.Join(", ", myList.ToArray()); to achieve this. It's an extra step, but it could be put in an extension method on System.Collections.Generic.List<T> to make it a bit easier. Something like this:

public static class GenericListExtensions
{
    public static string ToString<T>(this IList<T> list)
    {
        return string.Join(", ", list);
    }
}

(Note that this is free-hand and untested code. I don't have a compiler handy at the moment. So you'll want to experiment with it a little.)

Specified cast is not valid.. how to resolve this

Use Convert.ToDouble(value) rather than (double)value. It takes an object and supports all of the types you asked for! :)

Also, your method is always returning a string in the code above; I'd recommend having the method indicate so, and give it a more obvious name (public string FormatLargeNumber(object value))

set background color: Android

By the way, a good tip on quickly selecting color on the newer versions of AS is simply to type #fff and then using the color picker on the side of the code to choose the one you want. Quick and easier than remembering all the color hexadecimals. For example:

android:background="#fff"

Playing .mp3 and .wav in Java?

I have other methods for that, the first is :

public static void playAudio(String filePath){

    try{
        InputStream mus = new FileInputStream(new File(filePath));
        AudioStream aud = new AudioStream(mus);
    }catch(Exception e){
        JOptionPane.showMessageDialig(null, "You have an Error");
    }

And the second is :

try{
    JFXPanel x = JFXPanel();
    String u = new File("021.mp3").toURI().toString();
    new MediaPlayer(new Media(u)).play();
} catch(Exception e){
    JOPtionPane.showMessageDialog(null, e);
}

And if we want to make loop to this audio we use this method.

try{
    AudioData d = new AudioStream(new FileInputStream(filePath)).getData();
    ContinuousAudioDataStream s = new ContinuousAudioDataStream(d);
    AudioPlayer.player.start(s);
} catch(Exception ex){
    JOPtionPane.showMessageDialog(null, ex);
}

if we want to stop this loop we add this libreries in the try:

AudioPlayer.player.stop(s);

for this third method we add the folowing imports :

import java.io.FileInputStream;
import sun.audio.AudioData;
import sun.audio.AudioStream;
import sun.audio.ContinuousAudioDataStream;

Query Mongodb on month, day, year... of a datetime

Dates are stored in their timestamp format. If you want everything that belongs to a specific month, query for the start and the end of the month.

var start = new Date(2010, 11, 1);
var end = new Date(2010, 11, 30);

db.posts.find({created_on: {$gte: start, $lt: end}});
//taken from http://cookbook.mongodb.org/patterns/date_range/

How do I bind Twitter Bootstrap tooltips to dynamically created elements?

Try this one:

$('body').tooltip({
    selector: '[rel=tooltip]'
});

How do you get the "object reference" of an object in java when toString() and hashCode() have been overridden?

This is how I solved it:

Integer.toHexString(System.identityHashCode(object));

Pip freeze vs. pip list

To answer the second part of this question, the two packages shown in pip list but not pip freeze are setuptools (which is easy_install) and pip itself.

It looks like pip freeze just doesn't list packages that pip itself depends on. You may use the --all flag to show also those packages.

From the documentation:

--all

Do not skip these packages in the output: pip, setuptools, distribute, wheel

How do I make HttpURLConnection use a proxy?

You can also set

-Djava.net.useSystemProxies=true

On Windows and Linux this will use the system settings so you don't need to repeat yourself (DRY)

http://docs.oracle.com/javase/7/docs/api/java/net/doc-files/net-properties.html#Proxies

How to calculate sum of a formula field in crystal Reports?

You can try like this:

Sum({Tablename.Columnname})

It will work without creating a summarize field in formulae.

Getting a list of associative array keys

Simple jQuery way:

This is what I use:

DictionaryObj being the JavaScript dictionary object you want to go through. And value, key of course being the names of them in the dictionary.

$.each(DictionaryObj, function (key, value) {
    $("#storeDuplicationList")
        .append($("<li></li>")
        .attr("value", key)
        .text(value));
});

Differences between hard real-time, soft real-time, and firm real-time?

After reading the Wikipedia page and other pages on real-time computing. I made the following inferences:

1> For a Hard real-time system, if the system fails to meet the deadline even once the system is considered to have Failed.

2> For a Firm real-time system, even if the system fails to meet the deadline, possibly more than once (i.e. for multiple requests), the system is not considered to have failed. Also, the responses for the requests (replies to a query, result of a task, etc.) are worthless once the deadline for that particular request has passed (The usefulness of a result is zero after its deadline). A hypothetical example can be a storm forecast system (if a storm is predicted before arrival, then the system has done its job, prediction after the event has already happened or when it is happening is of no value).

3> For a Soft real-time system, even if the system fails to meet the deadline, possibly more than once (i.e. for multiple requests), the system is not considered to have failed. But, in this case the results of the requests are not worthless value for a result after its deadline, is not zero, rather it degrades as time passes after the deadline. Eg.: Streaming audio-video.

Here is a link to a resource that was very helpful.

Differences between dependencyManagement and dependencies in Maven

There's still one thing that is not highlighted enough, in my opinion, and that is unwanted inheritance.

Here's an incremental example:

I declare in my parent pom:

<dependencies>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>19.0</version>
        </dependency>
</dependencies>

boom! I have it in my Child A, Child B and Child C modules:

  • Implicilty inherited by child poms
  • A single place to manage
  • No need to redeclare anything in child poms
  • I can still redelcare and override to version 18.0 in a Child B if I want to.

But what if I end up not needing guava in Child C, and neither in the future Child D and Child E modules?

They will still inherit it and this is undesired! This is just like Java God Object code smell, where you inherit some useful bits from a class, and a tonn of unwanted stuff as well.

This is where <dependencyManagement> comes into play. When you add this to your parent pom, all of your child modules STOP seeing it. And thus you are forced to go into each individual module that DOES need it and declare it again (Child A and Child B, without the version though).

And, obviously, you don't do it for Child C, and thus your module remains lean.

Get the last day of the month in SQL

Take some base date which is the 31st of some month e.g. '20011231'. Then use the
following procedure (I have given 3 identical examples below, only the @dt value differs).

declare @dt datetime;

set @dt = '20140312'

SELECT DATEADD(month, DATEDIFF(month, '20011231', @dt), '20011231');



set @dt = '20140208'

SELECT DATEADD(month, DATEDIFF(month, '20011231', @dt), '20011231');



set @dt = '20140405'

SELECT DATEADD(month, DATEDIFF(month, '20011231', @dt), '20011231');

Constructing pandas DataFrame from values in variables gives "ValueError: If using all scalar values, you must pass an index"

Pandas magic at work. All logic is out.

The error message "ValueError: If using all scalar values, you must pass an index" Says you must pass an index.

This does not necessarily mean passing an index makes pandas do what you want it to do

When you pass an index, pandas will treat your dictionary keys as column names and the values as what the column should contain for each of the values in the index.

a = 2
b = 3
df2 = pd.DataFrame({'A':a,'B':b}, index=[1])

    A   B
1   2   3

Passing a larger index:

df2 = pd.DataFrame({'A':a,'B':b}, index=[1, 2, 3, 4])

    A   B
1   2   3
2   2   3
3   2   3
4   2   3

An index is usually automatically generated by a dataframe when none is given. However, pandas does not know how many rows of 2 and 3 you want. You can however be more explicit about it

df2 = pd.DataFrame({'A':[a]*4,'B':[b]*4})
df2

    A   B
0   2   3
1   2   3
2   2   3
3   2   3

The default index is 0 based though.

I would recommend always passing a dictionary of lists to the dataframe constructor when creating dataframes. It's easier to read for other developers. Pandas has a lot of caveats, don't make other developers have to experts in all of them in order to read your code.

File to import not found or unreadable: compass

I was uninstalled compass 1.0.1 and install compass 0.12.7, this fix problem for me

$ sudo gem uninstall compass
$ sudo gem install compass -v 0.12.7

Copy a git repo without history

You can limit the depth of the history while cloning:

--depth <depth>
Create a shallow clone with a history truncated to the specified 
number of revisions.

Use this if you want limited history, but still some.

Loop through properties in JavaScript object with Lodash

For your stated desire to "check if a property exists" you can directly use Lo-Dash's has.

var exists = _.has(myObject, propertyNameToCheck);

What is the easiest way to encrypt a password when I save it to the registry?

Please also consider "salting" your hash (not a culinary concept!). Basically, that means appending some random text to the password before you hash it.

"The salt value helps to slow an attacker perform a dictionary attack should your credential store be compromised, giving you additional time to detect and react to the compromise."

To store password hashes:

a) Generate a random salt value:

byte[] salt = new byte[32];
System.Security.Cryptography.RNGCryptoServiceProvider.Create().GetBytes(salt);

b) Append the salt to the password.

// Convert the plain string pwd into bytes
byte[] plainTextBytes = System.Text UnicodeEncoding.Unicode.GetBytes(plainText);
// Append salt to pwd before hashing
byte[] combinedBytes = new byte[plainTextBytes.Length + salt.Length];
System.Buffer.BlockCopy(plainTextBytes, 0, combinedBytes, 0, plainTextBytes.Length);
System.Buffer.BlockCopy(salt, 0, combinedBytes, plainTextBytes.Length, salt.Length);

c) Hash the combined password & salt:

// Create hash for the pwd+salt
System.Security.Cryptography.HashAlgorithm hashAlgo = new System.Security.Cryptography.SHA256Managed();
byte[] hash = hashAlgo.ComputeHash(combinedBytes);

d) Append the salt to the resultant hash.

// Append the salt to the hash
byte[] hashPlusSalt = new byte[hash.Length + salt.Length];
System.Buffer.BlockCopy(hash, 0, hashPlusSalt, 0, hash.Length);
System.Buffer.BlockCopy(salt, 0, hashPlusSalt, hash.Length, salt.Length);

e) Store the result in your user store database.

This approach means you don't need to store the salt separately and then recompute the hash using the salt value and the plaintext password value obtained from the user.

Edit: As raw computing power becomes cheaper and faster, the value of hashing -- or salting hashes -- has declined. Jeff Atwood has an excellent 2012 update too lengthy to repeat in its entirety here which states:

This (using salted hashes) will provide the illusion of security more than any actual security. Since you need both the salt and the choice of hash algorithm to generate the hash, and to check the hash, it's unlikely an attacker would have one but not the other. If you've been compromised to the point that an attacker has your password database, it's reasonable to assume they either have or can get your secret, hidden salt.

The first rule of security is to always assume and plan for the worst. Should you use a salt, ideally a random salt for each user? Sure, it's definitely a good practice, and at the very least it lets you disambiguate two users who have the same password. But these days, salts alone can no longer save you from a person willing to spend a few thousand dollars on video card hardware, and if you think they can, you're in trouble.

Linq code to select one item

I'll tell you what worked for me:

int id = int.Parse(insertItem.OwnerTableView.DataKeyValues[insertItem.ItemIndex]["id_usuario"].ToString());

var query = user.First(x => x.id_usuario == id);
tbUsername.Text = query.username;
tbEmail.Text = query.email;
tbPassword.Text = query.password;

My id is the row I want to query, in this case I got it from a radGrid, then I used it to query, but this query returns a row, then you can assign the values you got from the query to textbox, or anything, I had to assign those to textbox.

How to Customize a Progress Bar In Android

Simplest way to create customize a progress bar in Android:

  1. Initialize and show dialog:

    MyProgressDialog progressdialog = new MyProgressDialog(getActivity());
    progressdialog.show();
    
  2. Create method:

    public class MyProgressDialog extends AlertDialog {
          public MyProgressDialog(Context context) {
              super(context);
              getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
          }
    
          @Override
          public void show() {
              super.show();
              setContentView(R.layout.dialog_progress);
          }
    }
    
  3. Create layout XML:

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:background="@android:color/transparent"
      android:clickable="true">
    
        <RelativeLayout
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_centerInParent="true">
    
          <ProgressBar
             android:id="@+id/progressbarr"
             android:layout_width="@dimen/eightfive"
             android:layout_height="@dimen/eightfive"
             android:layout_centerInParent="true"
            android:indeterminateDrawable="@drawable/progresscustombg" />
    
          <TextView
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_centerHorizontal="true"
             android:layout_below="@+id/progressbarr"
             android:layout_marginTop="@dimen/_3sdp"
             android:textColor="@color/white"
             android:text="Please wait"/>
        </RelativeLayout>
    </RelativeLayout>
    
  4. Create shape progresscustombg.xml and put res/drawable:

    <?xml version="1.0" encoding="utf-8"?>
    <rotate xmlns:android="http://schemas.android.com/apk/res/android"
      android:fromDegrees="0"
      android:pivotX="50%"
      android:pivotY="50%"
      android:toDegrees="360" >
    
        <shape
           android:innerRadiusRatio="3"
           android:shape="ring"
           android:thicknessRatio="20"
           android:useLevel="false" >
            <size
                android:height="@dimen/eightfive"
                android:width="@dimen/eightfive" />
    
            <gradient
                android:centerY="0.50"
                android:endColor="@color/color_green_icash"
                android:startColor="#FFFFFF"
                android:type="sweep"
                android:useLevel="false" />
        </shape>
    
    </rotate>
    

JavaScript isset() equivalent

If you want to check if an element exists, just use the following code:

if (object) {
  //if isset, return true
} else {
  //else return false
}

This is sample:

_x000D_
_x000D_
function switchDiv() {_x000D_
    if (document.querySelector("#divId")) {_x000D_
        document.querySelector("#divId").remove();_x000D_
    } else {_x000D_
        var newDiv = document.createElement("div");_x000D_
        newDiv.id = "divId";_x000D_
        document.querySelector("body").appendChild(newDiv);_x000D_
    }_x000D_
}_x000D_
_x000D_
document.querySelector("#btn").addEventListener("click", switchDiv);
_x000D_
#divId {_x000D_
    background: red;_x000D_
    height: 100px;_x000D_
    width: 100px;_x000D_
    position: relative;_x000D_
    _x000D_
}
_x000D_
<body>_x000D_
  <button id="btn">Let's Diiiv!</button>_x000D_
</body>
_x000D_
_x000D_
_x000D_

Assign output to variable in Bash

Same with something more complex...getting the ec2 instance region from within the instance.

INSTANCE_REGION=$(curl -s 'http://169.254.169.254/latest/dynamic/instance-identity/document' | python -c "import sys, json; print json.load(sys.stdin)['region']")

echo $INSTANCE_REGION

SHA512 vs. Blowfish and Bcrypt

Blowfish isn't better than MD5 or SHA512, as they serve different purposes. MD5 and SHA512 are hashing algorithms, Blowfish is an encryption algorithm. Two entirely different cryptographic functions.

How to set placeholder value using CSS?

Some type of input hasn't got the :after or :before pseudo-element, so you can use a background-image with an SVG text element:

    input {
       background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' version='1.1' height='50px' width='120px'><text x='0' y='15' fill='gray' font-size='15'>Type Something...</text></svg>");
       background-repeat: no-repeat;
    }

    input:focus {
       background-image: none;
    }

My codepen: https://codepen.io/Scario/pen/BaagbeZ

Error: [ng:areq] from angular controller

I had this error too, I changed the code like this then it worked.

html

 <html ng-app="app">

   <div ng-controller="firstCtrl">
       ...
   </div>

 </html>

app.js

(function(){

    var app = angular.module('app',[]);

    app.controller('firstCtrl',function($scope){    
         ...
    })

})();

You have to make sure that the name in module is same as ng-app

then div will be in the scope of firstCtrl

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

I received such an error in a Python-based web API's response .text, but it led me here, so this may help others with a similar issue (it's very difficult to filter response and request issues in a search when using requests..)

Using json.dumps() on the request data arg to create a correctly-escaped string of JSON before POSTing fixed the issue for me

requests.post(url, data=json.dumps(data))

C compile : collect2: error: ld returned 1 exit status

Your problem is the typo in the function CreateDectionary().You should change it to CreateDictionary(). collect2: error: ld returned 1 exit status is the same problem in both C and C++, usually it means that you have unresolved symbols. In your case is the typo that i mentioned before.

Programmatically stop execution of python script?

You could raise SystemExit(0) instead of going to all the trouble to import sys; sys.exit(0).

jQuery ajax call to REST service

I think there is no need to specify

'http://localhost:8080`" 

in the URI part.. because. if you specify it, You'll have to change it manually for every environment.

Only

"/restws/json/product/get" also works

How to access the correct `this` inside a callback?

We can not bind this to setTimeout(), as it always execute with global object (Window), if you want to access this context in the callback function then by using bind() to the callback function we can achieve as:

setTimeout(function(){
    this.methodName();
}.bind(this), 2000);

How to add an item to a drop down list in ASP.NET?

Try this, it will insert the list item at index 0;

DropDownList1.Items.Insert(0, new ListItem("Add New", ""));

Invoke native date picker from web-app on iOS/Android

Give Mobiscroll a try. The scroller style date and time picker was especially created for interaction on touch devices. It is pretty flexible, and easily customizable. It comes with iOS/Android themes.

How to select first and last TD in a row?

If the row contains some leading (or trailing) th tags before the td you should use the :first-of-type and the :last-of-type selectors. Otherwise the first td won't be selected if it's not the first element of the row.

This gives:

td:first-of-type, td:last-of-type {
    /* styles */
}

Reason to Pass a Pointer by Reference in C++?

One example is when you write a parser function and pass it a source pointer to read from, if the function is supposed to push that pointer forward behind the last character which has been correctly recognized by the parser. Using a reference to a pointer makes it clear then that the function will move the original pointer to update its position.

In general, you use references to pointers if you want to pass a pointer to a function and let it move that original pointer to some other position instead of just moving a copy of it without affecting the original.

Could not load file or assembly 'Microsoft.Web.Infrastructure,

I had this problem. I had the DLL included into the project and the setting to Copy Local was true by default. Don't know why it started, since that DLL was in the project for a long while. I've heard some mentions of ReSharper possibly removing it, but I can't say I've ran a unused reference removal.

What helped me was: - Running "Update-Package Microsoft.Web.Infrastructure -Reinstall" on the project, which updated the whole solution, but didn't end up helping in and of itself. - Then I went through the projects' references and set the Copy Local to false, and then back to true. This actually resulted in a line being added into CSPROJ file under the DLL reference: True. Or something along the lines... Either way, now the build was copying the files as expected.

OpenCV resize fails on large image with "error: (-215) ssize.area() > 0 in function cv::resize"

Turns out I had a .csv file at the end of the folder from which I was reading all the images. Once I deleted that it worked alright

Make sure that it's all images and that you don't have any other type of file

SQL join on multiple columns in same tables

Join like this:

ON a.userid = b.sourceid AND a.listid = b.destinationid;

Append text to file from command line without using io redirection

You can use the --append feature of tee:

cat file01.txt | tee --append bothFiles.txt 
cat file02.txt | tee --append bothFiles.txt 

Or shorter,

cat file01.txt file02.txt | tee --append bothFiles.txt 

I assume the request for no redirection (>>) comes from the need to use this in xargs or similar. So if that doesn't count, you can mute the output with >/dev/null.

How to catch exception correctly from http.request()?

The RxJS functions need to be specifically imported. An easy way to do this is to import all of its features with import * as Rx from "rxjs/Rx"

Then make sure to access the Observable class as Rx.Observable.

What is the difference between primary, unique and foreign key constraints, and indexes?

Primary Key and Unique Key are Entity integrity constraints

Primary key allows each row in a table to be uniquely identified and ensures that no duplicate rows exist and no null values are entered.

Unique key constraint is used to prevent the duplication of key values within the rows of a table and allow null values. (In oracle one null is not equal to another null).

  • KEY or INDEX refers to a normal non-unique index. Non-distinct values for the index are allowed, so the index may contain rows with identical values in all columns of the index. These indexes don't enforce any structure on your data so they are used only for speeding up queries.
  • UNIQUE refers to an index where all rows of the index must be unique. That is, the same row may not have identical non-NULL values for all columns in this index as another row. As well as being used to speed up queries, UNIQUE indexes can be used to enforce structure on data, because the database system does not allow this distinct values rule to be broken when inserting or updating data. Your database system may allow a UNIQUE index on columns which allow NULL values, in which case two rows are allowed to be identical if they both contain a NULL value (NULL is considered not equal to itself), though this is probably undesirable depending on your application.
  • PRIMARY acts exactly like a UNIQUE index, except that it is always named 'PRIMARY', and there may be only one on a table (and there should always be one; though some database systems don't enforce this). A PRIMARY index is intended as a way to uniquely identify any row in the table, so it shouldn't be used on any columns which allow NULL values. Your PRIMARY index should always be on the smallest number of columns that are sufficient to uniquely identify a row. Often, this is just one column containing a unique auto-incremented number, but if there is anything else that can uniquely identify a row, such as "countrycode" in a list of countries, you can use that instead.
  • FULLTEXT indexes are different to all of the above, and their behaviour differs more between database systems. Unlike the above three, which are typically b-tree (allowing for selecting, sorting or ranges starting from left most column) or hash (allowing for selection starting from left most column), FULLTEXT indexes are only useful for full text searches done with the MATCH() / AGAINST() clause.

see Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL?

Make an image follow mouse pointer

Ok, here's a simple box that follows the cursor

Doing the rest is a simple case of remembering the last cursor position and applying a formula to get the box to move other than exactly where the cursor is. A timeout would also be handy if the box has a limited acceleration and must catch up to the cursor after it stops moving. Replacing the box with an image is simple CSS (which can replace most of the setup code for the box). I think the actual thinking code in the example is about 8 lines.

Select the right image (use a sprite) to orientate the rocket.

Yeah, annoying as hell. :-)

_x000D_
_x000D_
function getMouseCoords(e) {
  var e = e || window.event;
  document.getElementById('container').innerHTML = e.clientX + ', ' +
    e.clientY + '<br>' + e.screenX + ', ' + e.screenY;
}


var followCursor = (function() {
  var s = document.createElement('div');
  s.style.position = 'absolute';
  s.style.margin = '0';
  s.style.padding = '5px';
  s.style.border = '1px solid red';
  s.textContent = ""

  return {
    init: function() {
      document.body.appendChild(s);
    },

    run: function(e) {
      var e = e || window.event;
      s.style.left = (e.clientX - 5) + 'px';
      s.style.top = (e.clientY - 5) + 'px';
      getMouseCoords(e);
    }
  };
}());

window.onload = function() {
  followCursor.init();
  document.body.onmousemove = followCursor.run;
}
_x000D_
#container {
  width: 1000px;
  height: 1000px;
  border: 1px solid blue;
}
_x000D_
<div id="container"></div>
_x000D_
_x000D_
_x000D_

How to convert Set<String> to String[]?

In Java 11 we can use Collection.toArray(generator) method. The following code will create a new array of String:

Set<String> set = Set.of("one", "two", "three");
String[] array = set.toArray(String[]::new)

See: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/Collection.html#toArray(java.util.function.IntFunction)

Defining custom attrs

Currently the best documentation is the source. You can take a look at it here (attrs.xml).

You can define attributes in the top <resources> element or inside of a <declare-styleable> element. If I'm going to use an attr in more than one place I put it in the root element. Note, all attributes share the same global namespace. That means that even if you create a new attribute inside of a <declare-styleable> element it can be used outside of it and you cannot create another attribute with the same name of a different type.

An <attr> element has two xml attributes name and format. name lets you call it something and this is how you end up referring to it in code, e.g., R.attr.my_attribute. The format attribute can have different values depending on the 'type' of attribute you want.

  • reference - if it references another resource id (e.g, "@color/my_color", "@layout/my_layout")
  • color
  • boolean
  • dimension
  • float
  • integer
  • string
  • fraction
  • enum - normally implicitly defined
  • flag - normally implicitly defined

You can set the format to multiple types by using |, e.g., format="reference|color".

enum attributes can be defined as follows:

<attr name="my_enum_attr">
  <enum name="value1" value="1" />
  <enum name="value2" value="2" />
</attr>

flag attributes are similar except the values need to be defined so they can be bit ored together:

<attr name="my_flag_attr">
  <flag name="fuzzy" value="0x01" />
  <flag name="cold" value="0x02" />
</attr>

In addition to attributes there is the <declare-styleable> element. This allows you to define attributes a custom view can use. You do this by specifying an <attr> element, if it was previously defined you do not specify the format. If you wish to reuse an android attr, for example, android:gravity, then you can do that in the name, as follows.

An example of a custom view <declare-styleable>:

<declare-styleable name="MyCustomView">
  <attr name="my_custom_attribute" />
  <attr name="android:gravity" />
</declare-styleable>

When defining your custom attributes in XML on your custom view you need to do a few things. First you must declare a namespace to find your attributes. You do this on the root layout element. Normally there is only xmlns:android="http://schemas.android.com/apk/res/android". You must now also add xmlns:whatever="http://schemas.android.com/apk/res-auto".

Example:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:whatever="http://schemas.android.com/apk/res-auto"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

    <org.example.mypackage.MyCustomView
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:gravity="center"
      whatever:my_custom_attribute="Hello, world!" />
</LinearLayout>

Finally, to access that custom attribute you normally do so in the constructor of your custom view as follows.

public MyCustomView(Context context, AttributeSet attrs, int defStyle) {
  super(context, attrs, defStyle);

  TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyCustomView, defStyle, 0);

  String str = a.getString(R.styleable.MyCustomView_my_custom_attribute);

  //do something with str

  a.recycle();
}

The end. :)

How to change font size on part of the page in LaTeX?

Example:

\Large\begin{verbatim}
   <how to set font size here to 10 px ? />
\end{verbatim}
\normalsize

\Large can be obviously substituted by one of:

\tiny
\scriptsize
\footnotesize
\small
\normalsize
\large
\Large
\LARGE
\huge
\Huge

If you need arbitrary font sizes:

How can I hide an HTML table row <tr> so that it takes up no space?

I would really like to see your TABLE's styling. E.g. "border-collapse"

Just a guess, but it might affect how 'hidden' rows are being rendered.

HTTP Ajax Request via HTTPS Page

This is not possible due to the Same Origin Policy.

You will need to switch the Ajax requests to https, too.

Python Hexadecimal

Use the format() function with a '02x' format.

>>> format(255, '02x')
'ff'
>>> format(2, '02x')
'02'

The 02 part tells format() to use at least 2 digits and to use zeros to pad it to length, x means lower-case hexadecimal.

The Format Specification Mini Language also gives you X for uppercase hex output, and you can prefix the field width with # to include a 0x or 0X prefix (depending on wether you used x or X as the formatter). Just take into account that you need to adjust the field width to allow for those extra 2 characters:

>>> format(255, '02X')
'FF'
>>> format(255, '#04x')
'0xff'
>>> format(255, '#04X')
'0XFF'

Days between two dates?

Try:

(b-a).days

I tried with b and a of type datetime.date.

How do I hide the PHP explode delimiter from submitted form results?

<select name="FakeName" id="Fake-ID" aria-required="true" required>  <?php $options=nl2br(file_get_contents("employees.txt")); $options=explode("<br />",$options);  foreach ($options as $item_array) { echo "<option value='".$item_array"'>".$item_array"</option>";  } ?> </select> 

How to serialize an Object into a list of URL query parameters?

_x000D_
_x000D_
const obj = { id: 1, name: 'Neel' };_x000D_
let str = '';_x000D_
str = Object.entries(obj).map(([key, val]) => `${key}=${val}`).join('&');_x000D_
console.log(str);
_x000D_
_x000D_
_x000D_

Returning IEnumerable<T> vs. IQueryable<T>

I recently ran into an issue with IEnumerable v. IQueryable. The algorithm being used first performed an IQueryable query to obtain a set of results. These were then passed to a foreach loop, with the items instantiated as an Entity Framework (EF) class. This EF class was then used in the from clause of a Linq to Entity query, causing the result to be IEnumerable.

I'm fairly new to EF and Linq for Entities, so it took a while to figure out what the bottleneck was. Using MiniProfiling, I found the query and then converted all of the individual operations to a single IQueryable Linq for Entities query. The IEnumerable took 15 seconds and the IQueryable took 0.5 seconds to execute. There were three tables involved and, after reading this, I believe that the IEnumerable query was actually forming a three table cross-product and filtering the results.

Try to use IQueryables as a rule-of-thumb and profile your work to make your changes measurable.

Simple DatePicker-like Calendar

this datepicker is an excellent solution. datepickers are a must if you want to avoid code injection.

How to add custom method to Spring Data JPA

I use SimpleJpaRepository as the base class of repository implementation and add custom method in the interface,eg:

public interface UserRepository  {
    User FindOrInsert(int userId);
}

@Repository
public class UserRepositoryImpl extends SimpleJpaRepository implements UserRepository {

    private RedisClient redisClient;

    public UserRepositoryImpl(RedisClient redisClient, EntityManager em) {
        super(User.class, em);
        this.redisClient = redisClient;
    }


@Override
public User FindOrInsert(int userId) {

    User u = redisClient.getOrSet("test key.. User.class, () -> {
        Optional<User> ou = this.findById(Integer.valueOf(userId));
        return ou.get();
    });
    …………
    return u;
}

Reverse for '*' with arguments '()' and keyword arguments '{}' not found

Shell calls to reverse (as mentioned above) are very good to debug these problems, but there are two critical conditions:

  • you must supply arguments that matches whatever arguments the view needs,
  • these arguments must match regexp patterns.

Yes, it's logical. Yes, it's also confusing because reverse will only throw the exception and won't give you any further hints.

An example of URL pattern:

url(r'^cookies/(?P<hostname>[^/]+)/(?P<url_id>\d+)/$', 'register_site.views.show_cookies', name='show_cookies'),

And then what happens in shell:

>>> from register_site.views import show_cookies
>>> reverse(show_cookies)
NoReverseMatch: Reverse for 'register_site.views.show_cookies' with arguments '()' and keyword arguments '{}' not found.

It doesn't work because I supplied no arguments.

>>> reverse('show_cookies', kwargs={'url_id':123,'hostname': 'aaa'})
'/cookies/aaa/123'

Now it worked, but...

>>> reverse('show_cookies', kwargs={'url_id':'x','hostname': 'www.dupa.com'})
NoReverseMatch: Reverse for 'show_cookies' with arguments '()' and keyword arguments '{'url_id': 'x', 'hostname': 'www.dupa.com'}' not found.

Now it didn't work because url_id didn't match the regexp (expected numeric, supplied string).

You can use reverse with both positional arguments and keyword arguments. The syntax is:

reverse(viewname, urlconf=None, args=None, kwargs=None, prefix=None, current_app=None)

As it comes to the url template tag, there's funny thing about it. Django documentation gives example of using quoted view name:

{% url 'news.views.year_archive' yearvar %}

So I used it in a similar way in my HTML template:

{% url 'show_cookies' hostname=u.hostname url_id=u.pk %}

But this didn't work for me. But the exception message gave me a hint of what could be wrong - note the double single quotes around view name:

Reverse for ''show_cookies'' with arguments...

It started to work when I removed the quotes:

{% url show_cookies hostname=u.hostname url_id=u.pk %}

And this is confusing.

How do I send a cross-domain POST request via JavaScript?

  1. Create two hidden iframes (add "display: none;" to the css style). Make your second iframe point to something on your own domain.

  2. Create a hidden form, set its method to "post" with target = your first iframe, and optionally set enctype to "multipart/form-data" (I'm thinking you want to do POST because you want to send multipart data like pictures?)

  3. When ready, make the form submit() the POST.

  4. If you can get the other domain to return javascript that will do Cross-Domain Communication With Iframes (http://softwareas.com/cross-domain-communication-with-iframes) then you are in luck, and you can capture the response as well.

Of course, if you want to use your server as a proxy, you can avoid all this. Simply submit the form to your own server, which will proxy the request to the other server (assuming the other server isn't set up to notice IP discrepancies), get the response, and return whatever you like.

Defining arrays in Google Scripts

This may be of help to a few who are struggling like I was:

var data = myform.getRange("A:AA").getValues().pop();
var myvariable1 = data[4];
var myvariable2 = data[7];

How do I convert speech to text?

Late to the party, so answering more for future reference.

Advances in the field + Mozilla's mindset and agenda led to these two projects towards that end:

The latter has a 12GB data-set for download. The former allows for training a model with your own audio files to my understanding

How do I reference a local image in React?

For people who want to use multiple images of course importing them one by one would be a problem. The solution is to move the images folder to the public folder. So if you had an image at public/images/logo.jpg, you could display that image this way:

function Header() {
  return (
    <div>
      <img src="images/logo.jpg" alt="logo"/>
    </div>
  );
}

Yes, no need to use /public/ in the source.

Read further: https://daveceddia.com/react-image-tag/.

PHP display image BLOB from MySQL

This is what I use to display images from blob:

echo '<img src="data:image/jpeg;base64,'.base64_encode($image->load()) .'" />';

Cannot insert explicit value for identity column in table 'table' when IDENTITY_INSERT is set to OFF

In your entity for that table, add the DatabaseGenerated attribute above the column for which identity insert is set:

Example:

[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int TaskId { get; set; }

how to configuring a xampp web server for different root directory

I moved my htdocs folder from C:\xampp\htdocs to D:\htdocs without editing the Apache config file (httpd.conf).

Step 1) Move C:\xampp\htdocs folder to D:\htdocs Step 2) Create a symbolic link in C:\xampp\htdocs linked to D:\htdocs using mklink command.

D:\>mklink /J C:\xampp\htdocs D:\htdocs
Junction created for C:\xampp\htdocs <<===>> D:\htdocs

D:\>

Step 3) Done!

R barplot Y-axis scale too short

Simplest solution seems to be specifying the ylim range. Here is some code to do this automatically (left default, right - adjusted):

# default y-axis
barplot(dat, beside=TRUE)

# automatically adjusted y-axis
barplot(dat, beside=TRUE, ylim=range(pretty(c(0, dat))))

img

The trick is to use pretty() which returns a list of interval breaks covering all values of the provided data. It guarantees that the maximum returned value is 1) a round number 2) greater than maximum value in the data.

In the example 0 was also added pretty(c(0, dat)) which makes sure that axis starts from 0.

how to cancel/abort ajax request in axios

Using useEffect hook:

useEffect(() => {
  const ourRequest = Axios.CancelToken.source() // <-- 1st step

  const fetchPost = async () => {
    try {
      const response = await Axios.get(`endpointURL`, {
        cancelToken: ourRequest.token, // <-- 2nd step
      })
      console.log(response.data)
      setPost(response.data)
      setIsLoading(false)
    } catch (err) {
      console.log('There was a problem or request was cancelled.')
    }
  }
  fetchPost()

  return () => {
    ourRequest.cancel() // <-- 3rd step
  }
}, [])

Note: For POST request, pass cancelToken as 3rd argument

Axios.post(`endpointURL`, {data}, {
 cancelToken: ourRequest.token, // 2nd step
})

Is there a way to detect if an image is blurry?

During some work with an auto-focus lens, I came across this very useful set of algorithms for detecting image focus. It's implemented in MATLAB, but most of the functions are quite easy to port to OpenCV with filter2D.

It's basically a survey implementation of many focus measurement algorithms. If you want to read the original papers, references to the authors of the algorithms are provided in the code. The 2012 paper by Pertuz, et al. Analysis of focus measure operators for shape from focus (SFF) gives a great review of all of these measure as well as their performance (both in terms of speed and accuracy as applied to SFF).

EDIT: Added MATLAB code just in case the link dies.

function FM = fmeasure(Image, Measure, ROI)
%This function measures the relative degree of focus of 
%an image. It may be invoked as:
%
%   FM = fmeasure(Image, Method, ROI)
%
%Where 
%   Image,  is a grayscale image and FM is the computed
%           focus value.
%   Method, is the focus measure algorithm as a string.
%           see 'operators.txt' for a list of focus 
%           measure methods. 
%   ROI,    Image ROI as a rectangle [xo yo width heigth].
%           if an empty argument is passed, the whole
%           image is processed.
%
%  Said Pertuz
%  Abr/2010


if ~isempty(ROI)
    Image = imcrop(Image, ROI);
end

WSize = 15; % Size of local window (only some operators)

switch upper(Measure)
    case 'ACMO' % Absolute Central Moment (Shirvaikar2004)
        if ~isinteger(Image), Image = im2uint8(Image);
        end
        FM = AcMomentum(Image);

    case 'BREN' % Brenner's (Santos97)
        [M N] = size(Image);
        DH = Image;
        DV = Image;
        DH(1:M-2,:) = diff(Image,2,1);
        DV(:,1:N-2) = diff(Image,2,2);
        FM = max(DH, DV);        
        FM = FM.^2;
        FM = mean2(FM);

    case 'CONT' % Image contrast (Nanda2001)
        ImContrast = inline('sum(abs(x(:)-x(5)))');
        FM = nlfilter(Image, [3 3], ImContrast);
        FM = mean2(FM);

    case 'CURV' % Image Curvature (Helmli2001)
        if ~isinteger(Image), Image = im2uint8(Image);
        end
        M1 = [-1 0 1;-1 0 1;-1 0 1];
        M2 = [1 0 1;1 0 1;1 0 1];
        P0 = imfilter(Image, M1, 'replicate', 'conv')/6;
        P1 = imfilter(Image, M1', 'replicate', 'conv')/6;
        P2 = 3*imfilter(Image, M2, 'replicate', 'conv')/10 ...
            -imfilter(Image, M2', 'replicate', 'conv')/5;
        P3 = -imfilter(Image, M2, 'replicate', 'conv')/5 ...
            +3*imfilter(Image, M2, 'replicate', 'conv')/10;
        FM = abs(P0) + abs(P1) + abs(P2) + abs(P3);
        FM = mean2(FM);

    case 'DCTE' % DCT energy ratio (Shen2006)
        FM = nlfilter(Image, [8 8], @DctRatio);
        FM = mean2(FM);

    case 'DCTR' % DCT reduced energy ratio (Lee2009)
        FM = nlfilter(Image, [8 8], @ReRatio);
        FM = mean2(FM);

    case 'GDER' % Gaussian derivative (Geusebroek2000)        
        N = floor(WSize/2);
        sig = N/2.5;
        [x,y] = meshgrid(-N:N, -N:N);
        G = exp(-(x.^2+y.^2)/(2*sig^2))/(2*pi*sig);
        Gx = -x.*G/(sig^2);Gx = Gx/sum(Gx(:));
        Gy = -y.*G/(sig^2);Gy = Gy/sum(Gy(:));
        Rx = imfilter(double(Image), Gx, 'conv', 'replicate');
        Ry = imfilter(double(Image), Gy, 'conv', 'replicate');
        FM = Rx.^2+Ry.^2;
        FM = mean2(FM);

    case 'GLVA' % Graylevel variance (Krotkov86)
        FM = std2(Image);

    case 'GLLV' %Graylevel local variance (Pech2000)        
        LVar = stdfilt(Image, ones(WSize,WSize)).^2;
        FM = std2(LVar)^2;

    case 'GLVN' % Normalized GLV (Santos97)
        FM = std2(Image)^2/mean2(Image);

    case 'GRAE' % Energy of gradient (Subbarao92a)
        Ix = Image;
        Iy = Image;
        Iy(1:end-1,:) = diff(Image, 1, 1);
        Ix(:,1:end-1) = diff(Image, 1, 2);
        FM = Ix.^2 + Iy.^2;
        FM = mean2(FM);

    case 'GRAT' % Thresholded gradient (Snatos97)
        Th = 0; %Threshold
        Ix = Image;
        Iy = Image;
        Iy(1:end-1,:) = diff(Image, 1, 1);
        Ix(:,1:end-1) = diff(Image, 1, 2);
        FM = max(abs(Ix), abs(Iy));
        FM(FM<Th)=0;
        FM = sum(FM(:))/sum(sum(FM~=0));

    case 'GRAS' % Squared gradient (Eskicioglu95)
        Ix = diff(Image, 1, 2);
        FM = Ix.^2;
        FM = mean2(FM);

    case 'HELM' %Helmli's mean method (Helmli2001)        
        MEANF = fspecial('average',[WSize WSize]);
        U = imfilter(Image, MEANF, 'replicate');
        R1 = U./Image;
        R1(Image==0)=1;
        index = (U>Image);
        FM = 1./R1;
        FM(index) = R1(index);
        FM = mean2(FM);

    case 'HISE' % Histogram entropy (Krotkov86)
        FM = entropy(Image);

    case 'HISR' % Histogram range (Firestone91)
        FM = max(Image(:))-min(Image(:));


    case 'LAPE' % Energy of laplacian (Subbarao92a)
        LAP = fspecial('laplacian');
        FM = imfilter(Image, LAP, 'replicate', 'conv');
        FM = mean2(FM.^2);

    case 'LAPM' % Modified Laplacian (Nayar89)
        M = [-1 2 -1];        
        Lx = imfilter(Image, M, 'replicate', 'conv');
        Ly = imfilter(Image, M', 'replicate', 'conv');
        FM = abs(Lx) + abs(Ly);
        FM = mean2(FM);

    case 'LAPV' % Variance of laplacian (Pech2000)
        LAP = fspecial('laplacian');
        ILAP = imfilter(Image, LAP, 'replicate', 'conv');
        FM = std2(ILAP)^2;

    case 'LAPD' % Diagonal laplacian (Thelen2009)
        M1 = [-1 2 -1];
        M2 = [0 0 -1;0 2 0;-1 0 0]/sqrt(2);
        M3 = [-1 0 0;0 2 0;0 0 -1]/sqrt(2);
        F1 = imfilter(Image, M1, 'replicate', 'conv');
        F2 = imfilter(Image, M2, 'replicate', 'conv');
        F3 = imfilter(Image, M3, 'replicate', 'conv');
        F4 = imfilter(Image, M1', 'replicate', 'conv');
        FM = abs(F1) + abs(F2) + abs(F3) + abs(F4);
        FM = mean2(FM);

    case 'SFIL' %Steerable filters (Minhas2009)
        % Angles = [0 45 90 135 180 225 270 315];
        N = floor(WSize/2);
        sig = N/2.5;
        [x,y] = meshgrid(-N:N, -N:N);
        G = exp(-(x.^2+y.^2)/(2*sig^2))/(2*pi*sig);
        Gx = -x.*G/(sig^2);Gx = Gx/sum(Gx(:));
        Gy = -y.*G/(sig^2);Gy = Gy/sum(Gy(:));
        R(:,:,1) = imfilter(double(Image), Gx, 'conv', 'replicate');
        R(:,:,2) = imfilter(double(Image), Gy, 'conv', 'replicate');
        R(:,:,3) = cosd(45)*R(:,:,1)+sind(45)*R(:,:,2);
        R(:,:,4) = cosd(135)*R(:,:,1)+sind(135)*R(:,:,2);
        R(:,:,5) = cosd(180)*R(:,:,1)+sind(180)*R(:,:,2);
        R(:,:,6) = cosd(225)*R(:,:,1)+sind(225)*R(:,:,2);
        R(:,:,7) = cosd(270)*R(:,:,1)+sind(270)*R(:,:,2);
        R(:,:,7) = cosd(315)*R(:,:,1)+sind(315)*R(:,:,2);
        FM = max(R,[],3);
        FM = mean2(FM);

    case 'SFRQ' % Spatial frequency (Eskicioglu95)
        Ix = Image;
        Iy = Image;
        Ix(:,1:end-1) = diff(Image, 1, 2);
        Iy(1:end-1,:) = diff(Image, 1, 1);
        FM = mean2(sqrt(double(Iy.^2+Ix.^2)));

    case 'TENG'% Tenengrad (Krotkov86)
        Sx = fspecial('sobel');
        Gx = imfilter(double(Image), Sx, 'replicate', 'conv');
        Gy = imfilter(double(Image), Sx', 'replicate', 'conv');
        FM = Gx.^2 + Gy.^2;
        FM = mean2(FM);

    case 'TENV' % Tenengrad variance (Pech2000)
        Sx = fspecial('sobel');
        Gx = imfilter(double(Image), Sx, 'replicate', 'conv');
        Gy = imfilter(double(Image), Sx', 'replicate', 'conv');
        G = Gx.^2 + Gy.^2;
        FM = std2(G)^2;

    case 'VOLA' % Vollath's correlation (Santos97)
        Image = double(Image);
        I1 = Image; I1(1:end-1,:) = Image(2:end,:);
        I2 = Image; I2(1:end-2,:) = Image(3:end,:);
        Image = Image.*(I1-I2);
        FM = mean2(Image);

    case 'WAVS' %Sum of Wavelet coeffs (Yang2003)
        [C,S] = wavedec2(Image, 1, 'db6');
        H = wrcoef2('h', C, S, 'db6', 1);   
        V = wrcoef2('v', C, S, 'db6', 1);   
        D = wrcoef2('d', C, S, 'db6', 1);   
        FM = abs(H) + abs(V) + abs(D);
        FM = mean2(FM);

    case 'WAVV' %Variance of  Wav...(Yang2003)
        [C,S] = wavedec2(Image, 1, 'db6');
        H = abs(wrcoef2('h', C, S, 'db6', 1));
        V = abs(wrcoef2('v', C, S, 'db6', 1));
        D = abs(wrcoef2('d', C, S, 'db6', 1));
        FM = std2(H)^2+std2(V)+std2(D);

    case 'WAVR'
        [C,S] = wavedec2(Image, 3, 'db6');
        H = abs(wrcoef2('h', C, S, 'db6', 1));   
        V = abs(wrcoef2('v', C, S, 'db6', 1));   
        D = abs(wrcoef2('d', C, S, 'db6', 1)); 
        A1 = abs(wrcoef2('a', C, S, 'db6', 1));
        A2 = abs(wrcoef2('a', C, S, 'db6', 2));
        A3 = abs(wrcoef2('a', C, S, 'db6', 3));
        A = A1 + A2 + A3;
        WH = H.^2 + V.^2 + D.^2;
        WH = mean2(WH);
        WL = mean2(A);
        FM = WH/WL;
    otherwise
        error('Unknown measure %s',upper(Measure))
end
 end
%************************************************************************
function fm = AcMomentum(Image)
[M N] = size(Image);
Hist = imhist(Image)/(M*N);
Hist = abs((0:255)-255*mean2(Image))'.*Hist;
fm = sum(Hist);
end

%******************************************************************
function fm = DctRatio(M)
MT = dct2(M).^2;
fm = (sum(MT(:))-MT(1,1))/MT(1,1);
end

%************************************************************************
function fm = ReRatio(M)
M = dct2(M);
fm = (M(1,2)^2+M(1,3)^2+M(2,1)^2+M(2,2)^2+M(3,1)^2)/(M(1,1)^2);
end
%******************************************************************

A few examples of OpenCV versions:

// OpenCV port of 'LAPM' algorithm (Nayar89)
double modifiedLaplacian(const cv::Mat& src)
{
    cv::Mat M = (Mat_<double>(3, 1) << -1, 2, -1);
    cv::Mat G = cv::getGaussianKernel(3, -1, CV_64F);

    cv::Mat Lx;
    cv::sepFilter2D(src, Lx, CV_64F, M, G);

    cv::Mat Ly;
    cv::sepFilter2D(src, Ly, CV_64F, G, M);

    cv::Mat FM = cv::abs(Lx) + cv::abs(Ly);

    double focusMeasure = cv::mean(FM).val[0];
    return focusMeasure;
}

// OpenCV port of 'LAPV' algorithm (Pech2000)
double varianceOfLaplacian(const cv::Mat& src)
{
    cv::Mat lap;
    cv::Laplacian(src, lap, CV_64F);

    cv::Scalar mu, sigma;
    cv::meanStdDev(lap, mu, sigma);

    double focusMeasure = sigma.val[0]*sigma.val[0];
    return focusMeasure;
}

// OpenCV port of 'TENG' algorithm (Krotkov86)
double tenengrad(const cv::Mat& src, int ksize)
{
    cv::Mat Gx, Gy;
    cv::Sobel(src, Gx, CV_64F, 1, 0, ksize);
    cv::Sobel(src, Gy, CV_64F, 0, 1, ksize);

    cv::Mat FM = Gx.mul(Gx) + Gy.mul(Gy);

    double focusMeasure = cv::mean(FM).val[0];
    return focusMeasure;
}

// OpenCV port of 'GLVN' algorithm (Santos97)
double normalizedGraylevelVariance(const cv::Mat& src)
{
    cv::Scalar mu, sigma;
    cv::meanStdDev(src, mu, sigma);

    double focusMeasure = (sigma.val[0]*sigma.val[0]) / mu.val[0];
    return focusMeasure;
}

No guarantees on whether or not these measures are the best choice for your problem, but if you track down the papers associated with these measures, they may give you more insight. Hope you find the code useful! I know I did.

How to format numbers by prepending 0 to single-digit numbers?

    function colorOf(r,g,b){
  var f = function (x) {
    return (x<16 ? '0' : '') + x.toString(16) 
  };

  return "#" +  f(r) + f(g) + f(b);
}

What is the difference between an int and a long in C++?

When compiling for x64, the difference between int and long is somewhere between 0 and 4 bytes, depending on what compiler you use.

GCC uses the LP64 model, which means that ints are 32-bits but longs are 64-bits under 64-bit mode.

MSVC for example uses the LLP64 model, which means both ints and longs are 32-bits even in 64-bit mode.

How do I get the directory of the PowerShell script I execute?

PowerShell 3 has the $PSScriptRoot automatic variable:

Contains the directory from which a script is being run.

In Windows PowerShell 2.0, this variable is valid only in script modules (.psm1). Beginning in Windows PowerShell 3.0, it is valid in all scripts.

Don't be fooled by the poor wording. PSScriptRoot is the directory of the current file.

In PowerShell 2, you can calculate the value of $PSScriptRoot yourself:

# PowerShell v2
$PSScriptRoot = Split-Path -Parent -Path $MyInvocation.MyCommand.Definition

How to check if an alert exists using WebDriver?

The following (C# implementation, but similar in Java) allows you to determine if there is an alert without exceptions and without creating the WebDriverWait object.

boolean isDialogPresent(WebDriver driver) {
    IAlert alert = ExpectedConditions.AlertIsPresent().Invoke(driver);
    return (alert != null);
}

How to make PDF file downloadable in HTML link?

Don't loop through every file line. Use readfile instead, its faster. This is off the php site: http://php.net/manual/en/function.readfile.php

$file = $_GET["file"];
if (file_exists($file)) {
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header("Content-Type: application/force-download");
    header('Content-Disposition: attachment; filename=' . urlencode(basename($file)));
    // header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header('Content-Length: ' . filesize($file));
    ob_clean();
    flush();
    readfile($file);
    exit;
}

Make sure to sanitize your get variable as someone could download some php files...

Testing if a site is vulnerable to Sql Injection

The test has to be done on a page that queries a database so yes typically that is a login page because it's the page that can do the most harm but could be an unsecure page as well.

Generally you would have your database queries behind a secure login but if you just have a listing of items or something that you don't care if the world sees a hacker could append some sql injection to the end of the querystring.

The key with SQL Injection is the person doing the injection would have to know that your querying a database so if your not querying a database then no sql inject can be done. If your form is submitting to a database then yes they could SQL Inject that. It's always good practice to use either stored procedures to select/insert/update/delete or make sure you prepare or escape out all the statements that will be hitting the database.

JavaScript and getElementById for multiple elements with the same ID

The id is supposed to be unique, use the attribute "name" and "getelementsbyname" instead, and you'll have your array.

Remove table row after clicking table row delete button

As @gaurang171 mentioned, we can use .closest() which will return the first ancestor, or the closest to our delete button, and use .remove() to remove it.

This is how we can implement it using jQuery click event instead of using JavaScript onclick.

HTML:

<table id="myTable">
<tr>
  <th width="30%" style="color:red;">ID</th>
  <th width="25%" style="color:red;">Name</th>
  <th width="25%" style="color:red;">Age</th>
  <th width="1%"></th>
</tr>

<tr>
  <td width="30%" style="color:red;">SSS-001</td>
  <td width="25%" style="color:red;">Ben</td>
  <td width="25%" style="color:red;">25</td>
  <td><button type='button' class='btnDelete'>x</button></td>
</tr>

<tr>
  <td width="30%" style="color:red;">SSS-002</td>
  <td width="25%" style="color:red;">Anderson</td>
  <td width="25%" style="color:red;">47</td>
  <td><button type='button' class='btnDelete'>x</button></td>
</tr>

<tr>
  <td width="30%" style="color:red;">SSS-003</td>
  <td width="25%" style="color:red;">Rocky</td>
  <td width="25%" style="color:red;">32</td>
  <td><button type='button' class='btnDelete'>x</button></td>
</tr>

<tr>
  <td width="30%" style="color:red;">SSS-004</td>
  <td width="25%" style="color:red;">Lee</td>
  <td width="25%" style="color:red;">15</td>
  <td><button type='button' class='btnDelete'>x</button></td>
</tr>
                            

jQuery

 $(document).ready(function(){
     $("#myTable").on('click','.btnDelete',function(){
         $(this).closest('tr').remove();
      });
  });

Try in JSFiddle: click here.

How to return XML in ASP.NET?

Seems like at least 10 questions rolled into one here, a couple points.

Response.Clear - it really depends on what else is going on in the app - if you have httpmodules early in the pipeline that might be writing stuff you don't want - then clear it. Test it and find out. Fiddler or Wireshark useful for this.

Content Type to text/xml - yup - good idea - read up on HTTP spec as to why this is important. IMO anyone doing web work should have read the 1.0 and 1.1 spec at least once.

Encoding - how is your xml encoded - if it is utf-8, then say so, if not, say something else appropriate, just make sure they all match.

Page - personally, would use ashx or httpmodule, if you are using page, and want it a bit faster, get rid of autoeventwireup and bind the event handlers manually.

Would probably be a bit of a waste of memory to dump the xml into a string first, but it depends a lot on the size of the xml as to whether you would ever notice.

As others have suggested, saving the xml to the output stream probably the fastest, I would normally do that, but if you aren't sure, test it, don't rely on what you read on the interweb. Don't just believe anything I say.

For another approach, if the xml doesn't change that much, you could just write it to the disk and serve the file directly, which would likely be quite performant, but like everything in programming, it depends...

How do I extract value from Json

see this code what i am used in my application

String data="{'foo':'bar','coolness':2.0, 'altitude':39000, 'pilot':{'firstName':'Buzz','lastName':'Aldrin'}, 'mission':'apollo 11'}";

I retrieved like this

JSONObject json = (JSONObject) JSONSerializer.toJSON(data);        
    double coolness = json.getDouble( "coolness" );
    int altitude = json.getInt( "altitude" );
    JSONObject pilot = json.getJSONObject("pilot");
    String firstName = pilot.getString("firstName");
    String lastName = pilot.getString("lastName");

    System.out.println( "Coolness: " + coolness );
    System.out.println( "Altitude: " + altitude );
    System.out.println( "Pilot: " + lastName );

DirectX SDK (June 2010) Installation Problems: Error Code S1023

Find Microsoft Visual C++ 2010 x86/x64 Redistributable – 10.0.xxxxx in the control panel of the add or remove programs if xxxxx > 30319 renmove it

how to insert value into DataGridView Cell?

You can access any DGV cell as follows :

dataGridView1.Rows[rowIndex].Cells[columnIndex].Value = value;

But usually it's better to use databinding : you bind the DGV to a data source (DataTable, collection...) through the DataSource property, and only work on the data source itself. The DataGridView will automatically reflect the changes, and changes made on the DataGridView will be reflected on the data source

How to handle :java.util.concurrent.TimeoutException: android.os.BinderProxy.finalize() timed out after 10 seconds errors?

For classes that you create (ie. are not part of the Android) its possible to avoid the crash completely.

Any class that implements finalize() has some unavoidable probability of crashing as explained by @oba. So instead of using finalizers to perform cleanup, use a PhantomReferenceQueue.

For an example check out the implementation in React Native: https://github.com/facebook/react-native/blob/master/ReactAndroid/src/main/java/com/facebook/jni/DestructorThread.java

Running PHP script from the command line

UPDATE:

After misunderstanding, I finally got what you are trying to do. You should check your server configuration files; are you using apache2 or some other server software?

Look for lines that start with LoadModule php... There probably are configuration files/directories named mods or something like that, start from there.

You could also check output from php -r 'phpinfo();' | grep php and compare lines to phpinfo(); from web server.

To run php interactively:

(so you can paste/write code in the console)

php -a

To make it parse file and output to console:

php -f file.php

Parse file and output to another file:

php -f file.php > results.html

Do you need something else?

To run only small part, one line or like, you can use:

php -r '$x = "Hello World"; echo "$x\n";'

If you are running linux then do man php at console.

if you need/want to run php through fpm, use cli fcgi

SCRIPT_NAME="file.php" SCRIP_FILENAME="file.php" REQUEST_METHOD="GET" cgi-fcgi -bind -connect "/var/run/php-fpm/php-fpm.sock"

where /var/run/php-fpm/php-fpm.sock is your php-fpm socket file.

How do I push a local Git branch to master branch in the remote?

As an extend to @Eugene's answer another version which will work to push code from local repo to master/develop branch .

Switch to branch ‘master’:

$ git checkout master

Merge from local repo to master:

$ git merge --no-ff FEATURE/<branch_Name>

Push to master:

$ git push

How to pass data to view in Laravel?

You can pass data to the view using the with method.

return view('greeting', ['name' => 'James']);

Create a string of variable length, filled with a repeated character

Version that works in all browsers

This function does what you want, and performs a lot faster than the option suggested in the accepted answer :

var repeat = function(str, count) {
    var array = [];
    for(var i = 0; i <= count;)
        array[i++] = str;
    return array.join('');
}

You use it like this :

var repeatedCharacter = repeat("a", 10);

To compare the performance of this function with that of the option proposed in the accepted answer, see this Fiddle and this Fiddle for benchmarks.

Version for moderns browsers only

In modern browsers, you can now also do this :

var repeatedCharacter = "a".repeat(10) };

This option is even faster. However, unfortunately it doesn't work in any version of Internet explorer.

The numbers in the table specify the first browser version that fully supports the method :

enter image description here

Is there a good Valgrind substitute for Windows?

See the "Source Test Tools" link on the Software QA Testing and Test Tool Resources page for a list of similar tools.

I've used BoundsChecker,DevPartner Studio and Intel V-Tune in the past for profiling. I liked V-Tune the best; you could emulate various Intel chipsets and it would give you hints on how to optimize for that platform.

Finding first and last index of some value in a list in Python

s.index(x[, i[, j]])

index of the first occurrence of x in s (at or after index i and before index j)

Tool for comparing 2 binary files in Windows

Total Commander also has a binary compare option: go to: File \\Compare by content

ps. I guess some people may alredy be using this tool and may not be aware of the built-in feature.

Getting a directory name from a filename

Use boost::filesystem. It will be incorporated into the next standard anyway so you may as well get used to it.

Add back button to action bar

You'll need to check menuItem.getItemId() against android.R.id.home in the onOptionsItemSelected method

Duplicate of Android Sherlock ActionBar Up button

How to change current Theme at runtime in Android

This way work for me:

  @Override
protected void onCreate(Bundle savedInstanceState) {
    setTheme(GApplication.getInstance().getTheme());
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
}

Then you want to change a new theme:

GApplication.getInstance().setTheme(R.style.LightTheme);
recreate();

100% height minus header?

For "100% of the browser window", if you mean this literally, you should use fixed positioning. The top, bottom, right, and left properties are then used to offset the divs edges from the respective edges of the viewport:

#nav, #content{position:fixed;top:0px;bottom:0px;}
#nav{left:0px;right:235px;}
#content{left:235px;right:0px}

This will set up a screen with the left 235 pixels devoted to the nav, and the right rest of the screen to content.

Note, however, you won't be able to scroll the whole screen at once. Though you can set it to scroll either pane individually, by applying overflow:auto to either div.

Note also: fixed positioning is not supported in IE6 or earlier.

How to fix getImageData() error The canvas has been tainted by cross-origin data?

When working on local add a server

I had a similar issue when working on local. You url is going to be the path to the local file e.g. file:///Users/PeterP/Desktop/folder/index.html.

Please note that I am on a MAC.

I got round this by installing http-server globally. https://www.npmjs.com/package/http-server

Steps:

  1. Global install: npm install http-server -g
  2. Run server: http-server ~/Desktop/folder/

PS: I assume you have node installed, otherwise you wont get very far running npm commands.

What are the First and Second Level caches in (N)Hibernate?

There's a pretty good explanation of first level caching on the Streamline Logic blog.

Basically, first level caching happens on a per session basis where as second level caching can be shared across multiple sessions.

Append values to query string

The end to all URL query string editing woes

After lots of toil and fiddling with the Uri class, and other solutions, here're my string extension methods to solve my problems.

using System;
using System.Collections.Specialized;
using System.Linq;
using System.Web;

public static class StringExtensions
{
    public static string AddToQueryString(this string url, params object[] keysAndValues)
    {
        return UpdateQueryString(url, q =>
        {
            for (var i = 0; i < keysAndValues.Length; i += 2)
            {
                q.Set(keysAndValues[i].ToString(), keysAndValues[i + 1].ToString());
            }
        });
    }

    public static string RemoveFromQueryString(this string url, params string[] keys)
    {
        return UpdateQueryString(url, q =>
        {
            foreach (var key in keys)
            {
                q.Remove(key);
            }
        });
    }

    public static string UpdateQueryString(string url, Action<NameValueCollection> func)
    {
        var urlWithoutQueryString = url.Contains('?') ? url.Substring(0, url.IndexOf('?')) : url;
        var queryString = url.Contains('?') ? url.Substring(url.IndexOf('?')) : null;
        var query = HttpUtility.ParseQueryString(queryString ?? string.Empty);

        func(query);

        return urlWithoutQueryString + (query.Count > 0 ? "?" : string.Empty) + query;
    }
}

Git Push ERROR: Repository not found

first Create a new repository on the command line, name like Ademo.git

Create a new repository on the command line

touch README.md git init git add README.md git commit -m "first commit" git remote add origin https://github.com/your_name/Ademo.git git push -u origin master

Push an existing repository from the command line

git remote add origin https://github.com/your_name/Ademo.git git push -u origin master

Convert between UIImage and Base64 string

Swift 4.2 | Xcode 10

extension UIImage {

    /// EZSE: Returns base64 string
    public var base64: String {
        return self.jpegData(compressionQuality: 1.0)!.base64EncodedString()
    }
}

How to run a specific Android app using Terminal?

Use the cmd activity start-activity (or the alternative am start) command, which is a command-line interface to the ActivityManager. Use am to start activities as shown in this help:

$ adb shell am
usage: am [start|instrument]
       am start [-a <ACTION>] [-d <DATA_URI>] [-t <MIME_TYPE>]
                [-c <CATEGORY> [-c <CATEGORY>] ...]
                [-e <EXTRA_KEY> <EXTRA_VALUE> [-e <EXTRA_KEY> <EXTRA_VALUE> ...]
                [-n <COMPONENT>] [-D] [<URI>]
       ...

For example, to start the Contacts application, and supposing you know only the package name but not the Activity, you can use

$ pkg=com.google.android.contacts
$ comp=$(adb shell cmd package resolve-activity --brief -c android.intent.category.LAUNCHER $pkg | tail -1)
$ adb shell cmd activity start-activity $comp

or the alternative

$ adb shell am start -n $comp

See also http://www.kandroid.org/online-pdk/guide/instrumentation_testing.html (may be a copy of obsolete url : http://source.android.com/porting/instrumentation_testing.html ) for other details.

To terminate the application you can use

$ adb shell am kill com.google.android.contacts

or the more drastic

$ adb shell am force-stop com.google.android.contacts

No connection could be made because the target machine actively refused it (PHP / WAMP)

All I have to do in order to get rid of that error was to restart my wamp server.

How to detect when keyboard is shown and hidden

Swift 4:

  NotificationCenter.default.addObserver( self, selector: #selector(ControllerClassName.keyboardWillShow(_:)),
  name: Notification.Name.UIKeyboardWillShow,
  object: nil)
  NotificationCenter.default.addObserver(self, selector: #selector(ControllerClassName.keyboardWillHide(_:)),
  name: Notification.Name.UIKeyboardWillHide,
  object: nil)

Next, adding method to stop listening for notifications when the object’s life ends:-

Then add the promised methods from above to the view controller:
deinit {
  NotificationCenter.default.removeObserver(self)
}
func adjustKeyboardShow(_ open: Bool, notification: Notification) {
  let userInfo = notification.userInfo ?? [:]
  let keyboardFrame = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
  let height = (keyboardFrame.height + 20) * (open ? 1 : -1)
  scrollView.contentInset.bottom += height
  scrollView.scrollIndicatorInsets.bottom += height
}

@objc func keyboardWillShow(_ notification: Notification) {
  adjustKeyboardShow(true, notification: notification)
}
@objc func keyboardWillHide(_ notification: Notification) {
  adjustKeyboardShow(false, notification: notification)
}

How to add one column into existing SQL Table

What about something like:

Alter Table Products
Add LastUpdate varchar(200) null

Do you need something more complex than this?

What is the http-header "X-XSS-Protection"?

You can see in this List of useful HTTP headers.

X-XSS-Protection: This header enables the Cross-site scripting (XSS) filter built into most recent web browsers. It's usually enabled by default anyway, so the role of this header is to re-enable the filter for this particular website if it was disabled by the user. This header is supported in IE 8+, and in Chrome (not sure which versions). The anti-XSS filter was added in Chrome 4. Its unknown if that version honored this header.

Laravel-5 'LIKE' equivalent (Eloquent)

If you want to see what is run in the database use dd(DB::getQueryLog()) to see what queries were run.

Try this

BookingDates::where('email', Input::get('email'))
    ->orWhere('name', 'like', '%' . Input::get('name') . '%')->get();

How to completely uninstall Android Studio on Mac?

Run the following commands in the terminal:

rm -Rf /Applications/Android\ Studio.app  
rm -Rf ~/Library/Preferences/AndroidStudio*  
rm -Rf ~/Library/Preferences/com.google.android.*  
rm -Rf ~/Library/Preferences/com.android.*  
rm -Rf ~/Library/Application\ Support/AndroidStudio*  
rm -Rf ~/Library/Logs/AndroidStudio*  
rm -Rf ~/Library/Caches/AndroidStudio*  
rm -Rf ~/.AndroidStudio*  
rm -Rf ~/.gradle  
rm -Rf ~/.android  
rm -Rf ~/Library/Android*  
rm -Rf /usr/local/var/lib/android-sdk/  

To delete all projects:

rm -Rf ~/AndroidStudioProjects  

urlencoded Forward slash is breaking URL

Apache denies all URLs with %2F in the path part, for security reasons: scripts can't normally (ie. without rewriting) tell the difference between %2F and / due to the PATH_INFO environment variable being automatically URL-decoded (which is stupid, but a long-standing part of the CGI specification so there's nothing can be done about it).

You can turn this feature off using the AllowEncodedSlashes directive, but note that other web servers will still disallow it (with no option to turn that off), and that other characters may also be taboo (eg. %5C), and that %00 in particular will always be blocked by both Apache and IIS. So if your application relied on being able to have %2F or other characters in a path part you'd be limiting your compatibility/deployment options.

I am using urlencode() while preparing the search URL

You should use rawurlencode(), not urlencode() for escaping path parts. urlencode() is misnamed, it is actually for application/x-www-form-urlencoded data such as in the query string or the body of a POST request, and not for other parts of the URL.

The difference is that + doesn't mean space in path parts. rawurlencode() will correctly produce %20 instead, which will work both in form-encoded data and other parts of the URL.

How do I properly compare strings in C?

You can't (usefully) compare strings using != or ==, you need to use strcmp:

while (strcmp(check,input) != 0)

The reason for this is because != and == will only compare the base addresses of those strings. Not the contents of the strings themselves.

JPA : How to convert a native query result set to POJO class collection

Old style using ResultSet

@Transactional(readOnly=true)
public void accessUser() {
    EntityManager em = this.getEntityManager();
    org.hibernate.Session session = em.unwrap(org.hibernate.Session.class);
    session.doWork(new Work() {
        @Override
        public void execute(Connection con) throws SQLException {
            try (PreparedStatement stmt = con.prepareStatement(
                    "SELECT u.username, u.name, u.email, 'blabla' as passe, login_type as loginType FROM users u")) {
                ResultSet rs = stmt.executeQuery();
                ResultSetMetaData rsmd = rs.getMetaData();
                for (int i = 1; i <= rsmd.getColumnCount(); i++) {
                    System.out.print(rsmd.getColumnName(i) + " (" + rsmd.getColumnTypeName(i) + ") / ");
                }
                System.out.println("");
                while (rs.next()) {
                    System.out.println("Found username " + rs.getString("USERNAME") + " name " + rs.getString("NAME") + " email " + rs.getString("EMAIL") + " passe " + rs.getString("PASSE") + " email " + rs.getInt("LOGIN_TYPE"));
                }
            }
        }
    });
}

Laravel Eloquent ORM Transactions

If you don't like anonymous functions:

try {
    DB::connection()->pdo->beginTransaction();
    // database queries here
    DB::connection()->pdo->commit();
} catch (\PDOException $e) {
    // Woopsy
    DB::connection()->pdo->rollBack();
}

Update: For laravel 4, the pdo object isn't public anymore so:

try {
    DB::beginTransaction();
    // database queries here
    DB::commit();
} catch (\PDOException $e) {
    // Woopsy
    DB::rollBack();
}

The calling thread cannot access this object because a different thread owns it

this happened with me because I tried to access UI component in another thread insted of UI thread

like this

private void button_Click(object sender, RoutedEventArgs e)
{
    new Thread(SyncProcces).Start();
}

private void SyncProcces()
{
    string val1 = null, val2 = null;
    //here is the problem 
    val1 = textBox1.Text;//access UI in another thread
    val2 = textBox2.Text;//access UI in another thread
    localStore = new LocalStore(val1);
    remoteStore = new RemoteStore(val2);
}

to solve this problem, wrap any ui call inside what Candide mentioned above in his answer

private void SyncProcces()
{
    string val1 = null, val2 = null;
    this.Dispatcher.Invoke((Action)(() =>
    {//this refer to form in WPF application 
        val1 = textBox.Text;
        val2 = textBox_Copy.Text;
    }));
    localStore = new LocalStore(val1);
    remoteStore = new RemoteStore(val2 );
}

Soft hyphen in HTML (<wbr> vs. &shy;)

The zero-width space entity can be used in place of <wbr> tag reliably on virtually every platform.

&#8203;

Also useful is the word joiner entity, that can be used to prohibit a break. (Insert between each character of a word, except where you want the break.)

&#8288;

With the two of these, you can do anything.

How to integrate sourcetree for gitlab

I ended up using GitKraken . I've installed, auth and connected to my repo in 30 seconds.

How do I clear inner HTML

const destroy = container => {
  document.getElementById(container).innerHTML = '';
};

Faster previous

const destroyFast = container => {
  const el = document.getElementById(container);
  while (el.firstChild) el.removeChild(el.firstChild);
};

How to embed new Youtube's live video permanent URL?

The embed URL for a channel's live stream is:

https://www.youtube.com/embed/live_stream?channel=CHANNEL_ID

You can find your CHANNEL_ID at https://www.youtube.com/account_advanced

How to change angular port from 4200 to any other

No one has updated answer for latest Angular CLI.With latest Angular CLI

With latest version of angular-cli in which angular-cli.json renamed to angular.json , you can change the port by editing angular.json file you now specify a port per "project"

projects": {
    "my-cool-project": {
        ... rest of project config omitted
        "architect": {
            "serve": {
                "options": {
                    "port": 4500
                }
            }
        }
    }
}

Read more about it here

Unique device identification

I have following idea how you can deal with such Access Device ID (ADID):

Gen ADID

  • prepare web-page https://mypage.com/manager-login where trusted user e.g. Manager can login from device - that page should show button "Give access to this device"
  • when user press button, page send request to server to generate ADID
  • server gen ADID, store it on whitelist and return to page
  • then page store it in device localstorage
  • trusted user now logout.

Use device

  • Then other user e.g. Employee using same device go to https://mypage.com/statistics and page send to server request for statistics including parameter ADID (previous stored in localstorage)
  • server checks if the ADID is on the whitelist, and if yes then return data

In this approach, as long user use same browser and don't make device reset, the device has access to data. If someone made device-reset then again trusted user need to login and gen ADID.

You can even create some ADID management system for trusted user where on generate ADID he can also input device serial-number and in future in case of device reset he can find this device and regenerate ADID for it (which not increase whitelist size) and he can also drop some ADID from whitelist for devices which he will not longer give access to server data.

In case when sytem use many domains/subdomains te manager after login should see many "Give access from domain xyz.com to this device" buttons - each button will redirect device do proper domain, gent ADID and redirect back.

UPDATE

Simpler approach based on links:

  • Manager login to system using any device and generate ONE-TIME USE LINK https://mypage.com/access-link/ZD34jse24Sfses3J (which works e.g. 24h).
  • Then manager send this link to employee (or someone else; e.g. by email) which put that link into device and server returns ADID to device which store it in Local Storage. After that link above stops working - so only the system and device know ADID
  • Then employee using this device can read data from https://mypage.com/statistics because it has ADID which is on servers whitelist

How to export data from Spark SQL to CSV

You can use below statement to write the contents of dataframe in CSV format df.write.csv("/data/home/csv")

If you need to write the whole dataframe into a single CSV file, then use df.coalesce(1).write.csv("/data/home/sample.csv")

For spark 1.x, you can use spark-csv to write the results into CSV files

Below scala snippet would help

import org.apache.spark.sql.hive.HiveContext
// sc - existing spark context
val sqlContext = new HiveContext(sc)
val df = sqlContext.sql("SELECT * FROM testtable")
df.write.format("com.databricks.spark.csv").save("/data/home/csv")

To write the contents into a single file

import org.apache.spark.sql.hive.HiveContext
// sc - existing spark context
val sqlContext = new HiveContext(sc)
val df = sqlContext.sql("SELECT * FROM testtable")
df.coalesce(1).write.format("com.databricks.spark.csv").save("/data/home/sample.csv")

How do you select the entire excel sheet with Range using VBA?

I have found that the Worksheet ".UsedRange" method is superior in many instances to solve this problem. I struggled with a truncation issue that is a normal behaviour of the ".CurrentRegion" method. Using [ Worksheets("Sheet1").Range("A1").CurrentRegion ] does not yield the results I desired when the worksheet consists of one column with blanks in the rows (and the blanks are wanted). In this case, the ".CurrentRegion" will truncate at the first record. I implemented a work around but recently found an even better one; see code below that allows copying the whole set to another sheet or to identify the actual address (or just rows and columns):

Sub mytest_GetAllUsedCells_in_Worksheet()
    Dim myRange

    Set myRange = Worksheets("Sheet1").UsedRange
    'Alternative code:  set myRange = activesheet.UsedRange

   'use msgbox or debug.print to show the address range and counts
   MsgBox myRange.Address      
   MsgBox myRange.Columns.Count
   MsgBox myRange.Rows.Count

  'Copy the Range of data to another sheet
  'Note: contains all the cells with that are non-empty
   myRange.Copy (Worksheets("Sheet2").Range("A1"))
   'Note:  transfers all cells starting at "A1" location.  
   '       You can transfer to another area of the 2nd sheet
   '       by using an alternate starting location like "C5".

End Sub

Can constructors throw exceptions in Java?

Yes, constructors can throw exceptions. Usually this means that the new object is immediately eligible for garbage collection (although it may not be collected for some time, of course). It's possible for the "half-constructed" object to stick around though, if it's made itself visible earlier in the constructor (e.g. by assigning a static field, or adding itself to a collection).

One thing to be careful of about throwing exceptions in the constructor: because the caller (usually) will have no way of using the new object, the constructor ought to be careful to avoid acquiring unmanaged resources (file handles etc) and then throwing an exception without releasing them. For example, if the constructor tries to open a FileInputStream and a FileOutputStream, and the first succeeds but the second fails, you should try to close the first stream. This becomes harder if it's a subclass constructor which throws the exception, of course... it all becomes a bit tricky. It's not a problem very often, but it's worth considering.

force browsers to get latest js and css files in asp.net application

Interestingly, this very site has issues with the approach you describe in connection with some proxy setups, even though it should be fail-safe.

Check this Meta Stack Overflow discussion.

So in light of that, it might make sense not to use a GET parameter to update, but the actual file name:

href="/css/scriptname/versionNumber.css" 

even though this is more work to do, as you'll have to actually create the file, or build a URL rewrite for it.

Changing button color programmatically

use jquery :  $("#id").css("background","red");

What is the best way to ensure only one instance of a Bash script is running?

Advisory locking has been used for ages and it can be used in bash scripts. I prefer simple flock (from util-linux[-ng]) over lockfile (from procmail). And always remember about a trap on exit (sigspec == EXIT or 0, trapping specific signals is superfluous) in those scripts.

In 2009 I released my lockable script boilerplate (originally available at my wiki page, nowadays available as gist). Transforming that into one-instance-per-user is trivial. Using it you can also easily write scripts for other scenarios requiring some locking or synchronization.

Here is the mentioned boilerplate for your convenience.

#!/bin/bash
# SPDX-License-Identifier: MIT

## Copyright (C) 2009 Przemyslaw Pawelczyk <[email protected]>
##
## This script is licensed under the terms of the MIT license.
## https://opensource.org/licenses/MIT
#
# Lockable script boilerplate

### HEADER ###

LOCKFILE="/var/lock/`basename $0`"
LOCKFD=99

# PRIVATE
_lock()             { flock -$1 $LOCKFD; }
_no_more_locking()  { _lock u; _lock xn && rm -f $LOCKFILE; }
_prepare_locking()  { eval "exec $LOCKFD>\"$LOCKFILE\""; trap _no_more_locking EXIT; }

# ON START
_prepare_locking

# PUBLIC
exlock_now()        { _lock xn; }  # obtain an exclusive lock immediately or fail
exlock()            { _lock x; }   # obtain an exclusive lock
shlock()            { _lock s; }   # obtain a shared lock
unlock()            { _lock u; }   # drop a lock

### BEGIN OF SCRIPT ###

# Simplest example is avoiding running multiple instances of script.
exlock_now || exit 1

# Remember! Lock file is removed when one of the scripts exits and it is
#           the only script holding the lock or lock is not acquired at all.

Min and max value of input in angular4 application

Here is the solution :

This is kind of hack , but it will work

<input type="number" 
placeholder="Charge" 
[(ngModel)]="rateInput" 
name="rateInput"
pattern="^$|^([0-9]|[1-9][0-9]|[1][0][0])?"
required 
#rateInput2 = "ngModel">

<div *ngIf="rateInput2.errors && (rateInput2.dirty || rateInput2.touched)"
    <div [hidden]="!rateInput2.errors.pattern">
        Number should be between 0 and 100
    </div>
</div>

Here is the link to the plunker , please have a look.

How do I return a proper success/error message for JQuery .ajax() using PHP?

In order to build an AJAX webservice, you need TWO files :

  • A calling Javascript that sends data as POST (could be as GET) using JQuery AJAX
  • A PHP webservice that returns a JSON object (this is convenient to return arrays or large amount of data)

So, first you call your webservice using this JQuery syntax, in the JavaScript file :

$.ajax({
     url : 'mywebservice.php',
     type : 'POST',
     data : 'records_to_export=' + selected_ids, // On fait passer nos variables, exactement comme en GET, au script more_com.php
     dataType : 'json',
     success: function (data) {
          alert("The file is "+data.fichierZIP);
     },
     error: function(data) {
          //console.log(data);
          var responseText=JSON.parse(data.responseText);
          alert("Error(s) while building the ZIP file:\n"+responseText.messages);
     }
});

Your PHP file (mywebservice.php, as written in the AJAX call) should include something like this in its end, to return a correct Success or Error status:

<?php
    //...
    //I am processing the data that the calling Javascript just ordered (it is in the $_POST). In this example (details not shown), I built a ZIP file and have its filename in variable "$filename"
    //$errors is a string that may contain an error message while preparing the ZIP file
    //In the end, I check if there has been an error, and if so, I return an error object
    //...

    if ($errors==''){
        //if there is no error, the header is normal, and you return your JSON object to the calling JavaScript
        header('Content-Type: application/json; charset=UTF-8');
        $result=array();
        $result['ZIPFILENAME'] = basename($filename); 
        print json_encode($result);
    } else {
        //if there is an error, you should return a special header, followed by another JSON object
        header('HTTP/1.1 500 Internal Server Booboo');
        header('Content-Type: application/json; charset=UTF-8');
        $result=array();
        $result['messages'] = $errors;
        //feel free to add other information like $result['errorcode']
        die(json_encode($result));
    }
?>

How to copy a collection from one database to another in MongoDB

This won't solve your problem but the mongodb shell has a copyTo method that copies a collection into another one in the same database:

db.mycoll.copyTo('my_other_collection');

It also translates from BSON to JSON, so mongodump/mongorestore are the best way to go, as others have said.

Difference between a SOAP message and a WSDL?

A WSDL (Web Service Definition Language) is a meta-data file that describes the web service.

Things like operation name, parameters etc.

The soap messages are the actual payloads

Shadow Effect for a Text in Android?

Perhaps you'd consider using android:shadowColor, android:shadowDx, android:shadowDy, android:shadowRadius; alternatively setShadowLayer() ?

Check if object is a jQuery object

You can use the instanceof operator:

if (obj instanceof jQuery){
    console.log('object is jQuery');
}

Explanation: the jQuery function (aka $) is implemented as a constructor function. Constructor functions are to be called with the new prefix.

When you call $(foo), internally jQuery translates this to new jQuery(foo)1. JavaScript proceeds to initialize this inside the constructor function to point to a new instance of jQuery, setting it's properties to those found on jQuery.prototype (aka jQuery.fn). Thus, you get a new object where instanceof jQuery is true.


1It's actually new jQuery.prototype.init(foo): the constructor logic has been offloaded to another constructor function called init, but the concept is the same.

Why do many examples use `fig, ax = plt.subplots()` in Matplotlib/pyplot/python

As a supplement to the question and above answers there is also an important difference between plt.subplots() and plt.subplot(), notice the missing 's' at the end.

One can use plt.subplots() to make all their subplots at once and it returns the figure and axes (plural of axis) of the subplots as a tuple. A figure can be understood as a canvas where you paint your sketch.

# create a subplot with 2 rows and 1 columns
fig, ax = plt.subplots(2,1)

Whereas, you can use plt.subplot() if you want to add the subplots separately. It returns only the axis of one subplot.

fig = plt.figure() # create the canvas for plotting
ax1 = plt.subplot(2,1,1) 
# (2,1,1) indicates total number of rows, columns, and figure number respectively
ax2 = plt.subplot(2,1,2)

However, plt.subplots() is preferred because it gives you easier options to directly customize your whole figure

# for example, sharing x-axis, y-axis for all subplots can be specified at once
fig, ax = plt.subplots(2,2, sharex=True, sharey=True)

Shared axes whereas, with plt.subplot(), one will have to specify individually for each axis which can become cumbersome.

Excel Macro - Select all cells with data and format as table

Try this one for current selection:

Sub A_SelectAllMakeTable2()
    Dim tbl As ListObject
    Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, Selection, , xlYes)
    tbl.TableStyle = "TableStyleMedium15"
End Sub

or equivalent of your macro (for Ctrl+Shift+End range selection):

Sub A_SelectAllMakeTable()
    Dim tbl As ListObject
    Dim rng As Range

    Set rng = Range(Range("A1"), Range("A1").SpecialCells(xlLastCell))
    Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, rng, , xlYes)
    tbl.TableStyle = "TableStyleMedium15"
End Sub

Does Python have a toString() equivalent, and can I convert a db.Model element to String?

In function post():

todo.author = users.get_current_user()

So, to get str(todo.author), you need str(users.get_current_user()). What is returned by get_current_user() function ?

If it is an object, check does it contain a str()" function?

I think the error lies there.

How do you handle a "cannot instantiate abstract class" error in C++?

Why can't we create Object of Abstract Class ? When we create a pure virtual function in Abstract class, we reserve a slot for a function in the VTABLE(studied in last topic), but doesn't put any address in that slot. Hence the VTABLE will be incomplete. As the VTABLE for Abstract class is incomplete, hence the compiler will not let the creation of object for such class and will display an errror message whenever you try to do so.

Pure Virtual definitions

Pure Virtual functions can be given a small definition in the Abstract class, which you want all the derived classes to have. Still you cannot create object of Abstract class. Also, the Pure Virtual function must be defined outside the class definition. If you will define it inside the class definition, complier will give an error. Inline pure virtual definition is Illegal.

Is there a JavaScript / jQuery DOM change listener?

In addition to the "raw" tools provided by MutationObserver API, there exist "convenience" libraries to work with DOM mutations.

Consider: MutationObserver represents each DOM change in terms of subtrees. So if you're, for instance, waiting for a certain element to be inserted, it may be deep inside the children of mutations.mutation[i].addedNodes[j].

Another problem is when your own code, in reaction to mutations, changes DOM - you often want to filter it out.

A good convenience library that solves such problems is mutation-summary (disclaimer: I'm not the author, just a satisfied user), which enables you to specify queries of what you're interested in, and get exactly that.

Basic usage example from the docs:

var observer = new MutationSummary({
  callback: updateWidgets,
  queries: [{
    element: '[data-widget]'
  }]
});

function updateWidgets(summaries) {
  var widgetSummary = summaries[0];
  widgetSummary.added.forEach(buildNewWidget);
  widgetSummary.removed.forEach(cleanupExistingWidget);
}

docker : invalid reference format

I ran into this issue when I didn't have an environment variable set.

docker push ${repo}${image_name}:${tag}

repo and image_name were defined but tag wasn't.

This resulted in docker push repo/image_name:.

Which threw the docker: invalid reference format.

IOException: The process cannot access the file 'file path' because it is being used by another process

My below code solve this issue, but i suggest First of all you need to understand what causing this issue and try the solution which you can find by changing code

I can give another way to solve this issue but better solution is to check your coding structure and try to analyse what makes this happen,if you do not find any solution then you can go with this code below

try{
Start:
///Put your file access code here


}catch (Exception ex)
 {
//by anyway you need to handle this error with below code
   if (ex.Message.StartsWith("The process cannot access the file"))
    {
         //Wait for 5 seconds to free that file and then start execution again
         Thread.Sleep(5000);
         goto Start;
    }
 }

MVC: How to Return a String as JSON

Use the following code in your controller:

return Json(new { success = string }, JsonRequestBehavior.AllowGet);

and in JavaScript:

success: function (data) {
    var response = data.success;
    ....
}

Recyclerview inside ScrollView not scrolling smoothly

Try doing:

RecyclerView v = (RecyclerView) findViewById(...);
v.setNestedScrollingEnabled(false);

As an alternative, you can modify your layout using the support design library. I guess your current layout is something like:

<ScrollView >
   <LinearLayout >

       <View > <!-- upper content -->
       <RecyclerView > <!-- with custom layoutmanager -->

   </LinearLayout >
</ScrollView >

You can modify that to:

<CoordinatorLayout >

    <AppBarLayout >
        <CollapsingToolbarLayout >
             <!-- with your content, and layout_scrollFlags="scroll" -->
        </CollapsingToolbarLayout >
    </AppBarLayout >

    <RecyclerView > <!-- with standard layoutManager -->

</CoordinatorLayout >

However this is a longer road to take, and if you are OK with the custom linear layout manager, then just disable nested scrolling on the recycler view.

Edit (4/3/2016)

The v 23.2 release of the support libraries now includes a factory “wrap content” feature in all default LayoutManagers. I didn’t test it, but you should probably prefer it to that library you were using.

<ScrollView >
   <LinearLayout >

       <View > <!-- upper content -->
       <RecyclerView > <!-- with wrap_content -->

   </LinearLayout >
</ScrollView >

What's the best practice for primary keys in tables?

A natural key, if available, is usually best. So, if datetime/char uniquely identifies the row and both parts are meaningful to the row, that's great.

If just the datetime is meaningful, and the char is just tacked on to make it unique, then you might as well just go with an identify field.

What does the question mark operator mean in Ruby?

It's a convention in Ruby that methods that return boolean values end in a question mark. There's no more significance to it than that.

Set div height to fit to the browser using CSS

Setting window full height for empty divs

1st solution with absolute positioning - FIDDLE

.div1 {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 25%;
}
.div2 {
  position: absolute;
  top: 0;
  left: 25%;
  bottom: 0;
  width: 75%;
}

2nd solution with static (also can be used a relative) positioning & jQuery - FIDDLE

.div1 {
  float: left;
  width: 25%;
}
.div2 {
  float: left;
  width: 75%;
}

$(function(){
  $('.div1, .div2').css({ height: $(window).innerHeight() });
  $(window).resize(function(){
    $('.div1, .div2').css({ height: $(window).innerHeight() });
  });
});

What is the difference between GitHub and gist?

You can access Gist by visiting the following url gist.github.com. Alternatively you can access it from within your Github account (after logging in) as shown in the picture below:

how to access gist from within the github console

 

Github: A hosting service that houses a web-based git repository. It includes all the fucntionality of git with additional features added in.

 

Gist: Is an additional feature added to github to allow the sharing of code snippets, notes, to do lists and more. You can save your Gists as secret or public. Secret Gists are hidden from search engines but visible to anyone you share the url with.

For example. If you wanted to write a private to-do list. You could write one using Github Markdown as follows:

how to write a private to do list

NB: It is important to preserve the whitespace as shown above between the dash and brackets. It is also important that you save the file with the extension .md because we want the markdown to format properly. Remember to save this Gist as secret if you do not want others to see it.

 

The end result looks like the image below. The checkboxes are clickable because we saved this Gist with the extension .md

What the to do list looks like if you have formatted it properly

Using CSS for a fade-in effect on page load

In response to @A.M.K's question about how to do transitions without jQuery. A very simple example I threw together. If I had time to think this through some more, I might be able to eliminate the JavaScript code altogether:

<style>
    body {
        background-color: red;
        transition: background-color 2s ease-in;
    }
</style>

<script>
    window.onload = function() {
        document.body.style.backgroundColor = '#00f';
    }
</script>

<body>
    <p>test</p>
</body>

How to solve the system.data.sqlclient.sqlexception (0x80131904) error

Well, did you DO what the error says? You go to some length telling about installation, but what about the obvious?

  • Check the other server's network configuration in SQL Server.
  • Check the other machines FIREWALL. SQL Server does not open ports automatically, so the windows firewall normally blocks access..

XMLHttpRequest cannot load an URL with jQuery

Found a possible workaround that I don't believe was mentioned.

Here is a good description of the problem: http://www.asp.net/web-api/overview/security/enabling-cross-origin-requests-in-web-api

Basically as long as you use forms/url-encoded/plain text content types you are fine.

$.ajax({
    type: "POST",
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'text/plain'
    },
    dataType: "json",
    url: "http://localhost/endpoint",
    data: JSON.stringify({'DataToPost': 123}),
    success: function (data) {
        alert(JSON.stringify(data));
    }
});     

I use it with ASP.NET WebAPI2. So on the other end:

public static void RegisterWebApi(HttpConfiguration config)
{
    config.MapHttpAttributeRoutes();

    config.Formatters.Clear();
    config.Formatters.Add(new JsonMediaTypeFormatter());

    config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/plain"));
}

This way Json formatter gets used when parsing plain text content type.

And don't forget in Web.config:

<system.webServer>
<httpProtocol>
  <customHeaders>
    <add name="Access-Control-Allow-Origin" value="*" />
    <add name="Access-Control-Allow-Methods" value="GET, POST" />
  </customHeaders>
</httpProtocol>    

Hope this helps.

What is going wrong when Visual Studio tells me "xcopy exited with code 4"

It means:

Initialization error occurred. There is not enough memory or disk space, or you entered an invalid drive name or invalid syntax on the command line.

So basically it could be just about anything haha...try running the command one at a time from the command prompt to figure out which part of which command is giving you trouble.

HashMap(key: String, value: ArrayList) returns an Object instead of ArrayList?

I suppose your dictMap is of type HashMap, which makes it default to HashMap<Object, Object>. If you want it to be more specific, declare it as HashMap<String, ArrayList>, or even better, as HashMap<String, ArrayList<T>>

How to set a default value in react-select

If you've come here for react-select v2, and still having trouble - version 2 now only accepts an object as value, defaultValue, etc.

That is, try using value={{value: 'one', label: 'One'}}, instead of just value={'one'}.

Calculating the angle between the line defined by two points

Assumptions: x is the horizontal axis, and increases when moving from left to right. y is the vertical axis, and increases from bottom to top. (touch_x, touch_y) is the point selected by the user. (center_x, center_y) is the point at the center of the screen. theta is measured counter-clockwise from the +x axis. Then:

delta_x = touch_x - center_x
delta_y = touch_y - center_y
theta_radians = atan2(delta_y, delta_x)

Edit: you mentioned in a comment that y increases from top to bottom. In that case,

delta_y = center_y - touch_y

But it would be more correct to describe this as expressing (touch_x, touch_y) in polar coordinates relative to (center_x, center_y). As ChrisF mentioned, the idea of taking an "angle between two points" is not well defined.

How to get GET (query string) variables in Express.js on Node.js?

you can use url module to collect parameters by using url.parse

var url = require('url');
var url_data = url.parse(request.url, true);
var query = url_data.query;

In expressjs it's done by,

var id = req.query.id;

Eg:

var express = require('express');
var app = express();

app.get('/login', function (req, res, next) {
    console.log(req.query);
    console.log(req.query.id); //Give parameter id
});

What is a good pattern for using a Global Mutex in C#?

This example will exit after 5 seconds if another instance is already running.

// unique id for global mutex - Global prefix means it is global to the machine
const string mutex_id = "Global\\{B1E7934A-F688-417f-8FCB-65C3985E9E27}";

static void Main(string[] args)
{

    using (var mutex = new Mutex(false, mutex_id))
    {
        try
        {
            try
            {
                if (!mutex.WaitOne(TimeSpan.FromSeconds(5), false))
                {
                    Console.WriteLine("Another instance of this program is running");
                    Environment.Exit(0);
                }
            }
            catch (AbandonedMutexException)
            {
                // Log the fact the mutex was abandoned in another process, it will still get aquired
            }

            // Perform your work here.
        }
        finally
        {
            mutex.ReleaseMutex();
        }
    }
}

How to get Javascript Select box's selected text

In order to get the value of the selected item you can do the following:

this.options[this.selectedIndex].text

Here the different options of the select are accessed, and the SelectedIndex is used to choose the selected one, then its text is being accessed.

Read more about the select DOM here.

MSIE and addEventListener Problem in Javascript?

The problem is that IE does not have the standard addEventListener method. IE uses its own attachEvent which does pretty much the same.

Good explanation of the differences, and also about the 3rd parameter can be found at quirksmode.

Using malloc for allocation of multi-dimensional arrays with different row lengths

2-D Array Dynamic Memory Allocation

int **a,i;

// for any number of rows & columns this will work
a = (int **)malloc(rows*sizeof(int *));
for(i=0;i<rows;i++)
    *(a+i) = (int *)malloc(cols*sizeof(int));

How to get class object's name as a string in Javascript?

Shog9 is right that this doesn't make all that much sense to ask, since an object could be referred to by multiple variables. If you don't really care about that, and all you want is to find the name of one of the global variables that refers to that object, you could do the following hack:

function myClass() { 
  this.myName = function () { 
    // search through the global object for a name that resolves to this object
    for (var name in this.global) 
      if (this.global[name] == this) 
        return name 
  } 
}
// store the global object, which can be referred to as this at the top level, in a
// property on our prototype, so we can refer to it in our object's methods
myClass.prototype.global = this
// create a global variable referring to an object
var myVar = new myClass()
myVar.myName() // returns "myVar"

Note that this is an ugly hack, and should not be used in production code. If there is more than one variable referring to an object, you can't tell which one you'll get. It will only search the global variables, so it won't work if a variable is local to a function. In general, if you need to name something, you should pass the name in to the constructor when you create it.

edit: To respond to your clarification, if you need to be able to refer to something from an event handler, you shouldn't be referring to it by name, but instead add a function that refers to the object directly. Here's a quick example that I whipped up that shows something similar, I think, to what you're trying to do:

function myConstructor () {
  this.count = 0
  this.clickme = function () {
    this.count += 1
    alert(this.count)
  }

  var newDiv = document.createElement("div")
  var contents = document.createTextNode("Click me!")

  // This is the crucial part. We don't construct an onclick handler by creating a
  // string, but instead we pass in a function that does what we want. In order to
  // refer to the object, we can't use this directly (since that will refer to the 
  // div when running event handler), but we create an anonymous function with an 
  // argument and pass this in as that argument.
  newDiv.onclick = (function (obj) { 
    return function () {
      obj.clickme()
    }
  })(this)

  newDiv.appendChild(contents)
  document.getElementById("frobnozzle").appendChild(newDiv)

}
window.onload = function () {
  var myVar = new myConstructor()
}

What is this Javascript "require"?

It's used to load modules. Let's use a simple example.

In file circle_object.js:

var Circle = function (radius) {
    this.radius = radius
}
Circle.PI = 3.14

Circle.prototype = {
    area: function () {
        return Circle.PI * this.radius * this.radius;
    }
}

We can use this via require, like:

node> require('circle_object')
{}
node> Circle
{ [Function] PI: 3.14 }
node> var c = new Circle(3)
{ radius: 3 }
node> c.area()

The require() method is used to load and cache JavaScript modules. So, if you want to load a local, relative JavaScript module into a Node.js application, you can simply use the require() method.

Example:

var yourModule = require( "your_module_name" ); //.js file extension is optional

Writing to an Excel spreadsheet

If your need is to modify an existing workbook, the safest way would be to use pyoo. You need to have some libraries installed and it takes a few hoops to jump through but once its set up, this would be bulletproof as you are leveraging the wide and solid API's of LibreOffice / OpenOffice.

Please see my Gist on how to set up a linux system and do some basic coding using pyoo.

Here is an example of the code:

#!/usr/local/bin/python3
import pyoo
# Connect to LibreOffice using a named pipe 
# (named in the soffice process startup)
desktop = pyoo.Desktop(pipe='oo_pyuno')
wkbk = desktop.open_spreadsheet("<xls_file_name>")
sheet = wkbk.sheets['Sheet1']
# Write value 'foo' to cell E5 on Sheet1
sheet[4,4].value='foo'
wkbk.save()
wkbk.close()

Add views in UIStackView programmatically

Try below code,

UIView *view1 = [[UIView alloc]init];
view1.backgroundColor = [UIColor blackColor];
[view1 setFrame:CGRectMake(0, 0, 50, 50)];

UIView *view2 =  [[UIView alloc]init];
view2.backgroundColor = [UIColor greenColor];
[view2 setFrame:CGRectMake(0, 100, 100, 100)];

NSArray *subView = [NSArray arrayWithObjects:view1,view2, nil];

[self.stack1 initWithArrangedSubviews:subView];

Hope it works. Please let me know if you need anymore clarification.

How to hide "Showing 1 of N Entries" with the dataTables.js library

If you also need to disable the drop-down (not to hide the text) then set the lengthChange option to false

$('#datatable').dataTable( {
  "lengthChange": false
} );

Works for DataTables 1.10+

Read more in the official documentation

Random String Generator Returning Same String

This is my solution:

private string RandomString(int length)
{
    char[] symbols = { 
                            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
                            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'                             
                        };

    Stack<byte> bytes = new Stack<byte>();
    string output = string.Empty;

    for (int i = 0; i < length; i++)
    {
        if (bytes.Count == 0)
        {
            bytes = new Stack<byte>(Guid.NewGuid().ToByteArray());
        }
        byte pop = bytes.Pop();
        output += symbols[(int)pop % symbols.Length];
    }
    return output;
}

// get 1st random string 
string Rand1 = RandomString(4);

// get 2nd random string 
string Rand2 = RandomString(4);

// create full rand string
string docNum = Rand1 + "-" + Rand2;

Giving height to table and row in Bootstrap

CSS:

tr {
width: 100%;
display: inline-table;
height:60px;                // <-- the rows height 
}

table{
 height:300px;              // <-- Select the height of the table
 display: -moz-groupbox;    // For firefox bad effect
}
tbody{
  overflow-y: scroll;      
  height: 200px;            //  <-- Select the height of the body
  width: 100%;
  position: absolute;
}

Bootply : http://www.bootply.com/AgI8LpDugl

PHP parse/syntax errors; and how to solve them

Unexpected '='

This can be caused by having invalid characters in a variable name. Variables names must follow these rules:

Variable names follow the same rules as other labels in PHP. A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thus: '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*'

Using PHP Replace SPACES in URLS with %20

    public static function normalizeUrl(string $url) {
        $parts = parse_url($url);
        return $parts['scheme'] .
            '://' .
            $parts['host'] .
            implode('/', array_map('rawurlencode', explode('/', $parts['path'])));

    }

Sorted array list in Java

Lists typically preserve the order in which items are added. Do you definitely need a list, or would a sorted set (e.g. TreeSet<E>) be okay for you? Basically, do you need to need to preserve duplicates?

What are the sizes used for the iOS application splash screen?

2018 Update - Please don't use this info !

I'm leaving the below post for reference purposes.

Please read Apple's documentation Human Interface Guidelines - Launch Screens for details on launch screens and recommendations.

Thanks
Drekka


July 2012 - As this reply is rather old, but stills seems popular. I've written a blog post based on Apple's doco and placed it on my blog. I hope you guys find it useful.

Yes. In iPhone/iPad development the Default.png file is displayed by the device automatically so you don't have to program it which is really useful. I don't have it with me, but you need different PNGs for the iPad with specific names. I googled iPad default png and got this info from the phunkwerks site:


iPad Launch Image Orientations

To deal with various orientation options, a new naming convention has been created for iPad launch images. The screen size of the iPad is 768×1024, notice in the dimensions that follow the height takes into account a 20 pixel status bar.

Filename Dimensions

  • Default-Portrait.png * — 768w x 1024h
  • Default-PortraitUpsideDown.png — 768w x 1024h
  • Default-Landscape.png ** — 1024w x 748h
  • Default-LandscapeLeft.png — 1024w x 748h
  • Default-LandscapeRight.png — 1024w x 748h
  • iPad-Retina–Portrait.png — 1536w x 2048h
  • iPad-Retina–Landscape.png — 2048w x 1496h
  • Default.png — Not recommended

*—If you have not specified a Default-PortraitUpsideDown.png file, this file will take precedence.

**—If you have not specified a Default-LandscapeLeft.png or Default-LandscapeRight.png image file, this file will take precedence.

This link to "Apple's Developer Library" is useful, too.

How to write "Html.BeginForm" in Razor

The following code works fine:

@using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
{
    @Html.ValidationSummary(true)
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
}

and generates as expected:

<form action="/Upload/Upload" enctype="multipart/form-data" method="post">    
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
</form>

On the other hand if you are writing this code inside the context of other server side construct such as an if or foreach you should remove the @ before the using. For example:

@if (SomeCondition)
{
    using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
    {
        @Html.ValidationSummary(true)
        <fieldset>
            Select a file <input type="file" name="file" />
            <input type="submit" value="Upload" />
        </fieldset>
    }
}

As far as your server side code is concerned, here's how to proceed:

[HttpPost]
public ActionResult Upload(HttpPostedFileBase file) 
{
    if (file != null && file.ContentLength > 0) 
    {
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/content/pics"), fileName);
        file.SaveAs(path);
    }
    return RedirectToAction("Upload");
}

how to make label visible/invisible?

you could try

if (isValid) {
    document.getElementById("endTimeLabel").style.display = "none";
}else {
    document.getElementById("endTimeLabel").style.display = "block";
}

alone those lines

jquery remove "selected" attribute of option?

Using jQuery 1.9 and above:

$("#mySelect :selected").prop('selected', false);

How to Position a table HTML?

You would want to use CSS to achieve that.

say you have a table with the attribute id="my_table"

You would want to write the following in your css file

#my_table{
    margin-top:10px //moves your table 10pixels down
    margin-left:10px //moves your table 10pixels right
}

if you do not have a CSS file then you may just add margin-top:10px, margin-left:10px to the style attribute in your table element like so

<table style="margin-top:10px; margin-left:10px;">
    ....
</table>

There are a lot of resources on the net describing CSS and HTML in detail

Convert a positive number to negative in C#

To switch the sign of an integer, you just use the sign operator:

myInt = -myInt;

To make it negative regardless if the original value is negative or not, you first use the Abs method:

myInt = -Math.Abs(myInt);

How can I get the username of the logged-in user in Django?

You can use the request object to find the logged in user

def my_view(request):
    username = None
    if request.user.is_authenticated():
        username = request.user.username

According to https://docs.djangoproject.com/en/2.0/releases/1.10/

In version Django 2.0 the syntax has changed to

request.user.is_authenticated

Does C# have a String Tokenizer like Java's?

You could use String.Split method.

class ExampleClass
{
    public ExampleClass()
    {
        string exampleString = "there is a cat";
        // Split string on spaces. This will separate all the words in a string
        string[] words = exampleString.Split(' ');
        foreach (string word in words)
        {
            Console.WriteLine(word);
            // there
            // is
            // a
            // cat
        }
    }
}

For more information see Sam Allen's article about splitting strings in c# (Performance, Regex)

angularjs directive call function specified in attribute and pass an argument to it

This should work.

<div my-method='theMethodToBeCalled'></div>

app.directive("myMethod",function($parse) {
  restrict:'A',
  scope: {theMethodToBeCalled: "="}
  link:function(scope,element,attrs) {
     $(element).on('theEvent',function( e, rowid ) {
        id = // some function called to determine id based on rowid
        scope.theMethodToBeCalled(id);
     }
  }
}

app.controller("myController",function($scope) {
   $scope.theMethodToBeCalled = function(id) { alert(id); };
}

Getting around the Max String size in a vba function?

I may have missed something here, but why can't you just declare your string with the desired size? For example, in my VBA code I often use something like:

Dim AString As String * 1024

which provides for a 1k string. Obviously, you can use whatever declaration you like within the larger limits of Excel and available memory etc.

This may be a little inefficient in some cases, and you will probably wish to use Trim(AString) like constructs to obviate any superfluous trailing blanks. Still, it easily exceeds 256 chars.

array filter in python?

Use the Set type:

A_set = Set([6,7,8,9,10,11,12])
subset_of_A_set = Set([6,9,12])

result = A_set - subset_of_A_set

Start / Stop a Windows Service from a non-Administrator user account

It's significantly easier to grant management permissions to a service using one of these tools:

  • Group Policy
  • Security Template
  • subinacl.exe command-line tool.

Here's the MSKB article with instructions for Windows Server 2008 / Windows 7, but the instructions are the same for 2000 and 2003.

Open source face recognition for Android

You can try Microsoft's Face API. It can detect and identify people. learn more about face API here.

For homebrew mysql installs, where's my.cnf?

in my system it was

nano /usr/local/etc/my.cnf.default 

as template and

nano /usr/local/etc/my.cnf

as working.

Getting the difference between two Dates (months/days/hours/minutes/seconds) in Swift

   func dateDiff(dateStr:String) -> String {
            var f:NSDateFormatter = NSDateFormatter()
            f.timeZone = NSTimeZone.localTimeZone()
            f.dateFormat = "yyyy-M-dd'T'HH:mm:ss.SSSZZZ"

            var now = f.stringFromDate(NSDate())
            var startDate = f.dateFromString(dateStr)
            var endDate = f.dateFromString(now)
            var calendar: NSCalendar = NSCalendar.currentCalendar()

            let calendarUnits = NSCalendarUnit.CalendarUnitWeekOfMonth | NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitHour | NSCalendarUnit.CalendarUnitMinute | NSCalendarUnit.CalendarUnitSecond
            let dateComponents = calendar.components(calendarUnits, fromDate: startDate!, toDate: endDate!, options: nil)

            let weeks = abs(dateComponents.weekOfMonth)
            let days = abs(dateComponents.day)
            let hours = abs(dateComponents.hour)
            let min = abs(dateComponents.minute)
            let sec = abs(dateComponents.second)

            var timeAgo = ""

            if (sec > 0){
                if (sec > 1) {
                    timeAgo = "\(sec) Seconds Ago"
                } else {
                    timeAgo = "\(sec) Second Ago"
                }
            }

            if (min > 0){
                if (min > 1) {
                    timeAgo = "\(min) Minutes Ago"
                } else {
                    timeAgo = "\(min) Minute Ago"
                }
            }

            if(hours > 0){
                if (hours > 1) {
                    timeAgo = "\(hours) Hours Ago"
                } else {
                    timeAgo = "\(hours) Hour Ago"
                }
            }

            if (days > 0) {
                if (days > 1) {
                    timeAgo = "\(days) Days Ago"
                } else {
                    timeAgo = "\(days) Day Ago"
                }
            }

            if(weeks > 0){
                if (weeks > 1) {
                    timeAgo = "\(weeks) Weeks Ago"
                } else {
                    timeAgo = "\(weeks) Week Ago"
                }
            }

            print("timeAgo is===> \(timeAgo)")
            return timeAgo;
        }

iPhone UIView Animation Best Practice

let's do try and checkout For Swift 3...

UIView.transition(with: mysuperview, duration: 0.75, options:UIViewAnimationOptions.transitionFlipFromRight , animations: {
    myview.removeFromSuperview()
}, completion: nil)

Disabling radio buttons with jQuery

I just built a sandbox environment with your code and it worked for me. Here is what I used:

<html>
  <head>
    <title>test</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
  </head>
  <body>
    <form id="chatTickets" method="post" action="/admin/index.cfm/">
      <input id="ticketID1" type="radio" checked="checked" value="myvalue1" name="ticketID"/>
      <input id="ticketID2" type="radio" checked="checked" value="myvalue2" name="ticketID"/>
    </form>
    <a href="#" title="Load ActiveChat" id="loadActive">Load Active</a>

    <script>
      jQuery("#loadActive").click(function() {
        //I have other code in here that runs before this function call
        writeData();
      });
      function writeData() {
        jQuery("input[name='ticketID']").each(function(i) {
            jQuery(this).attr('disabled', 'disabled');
        });
      }
    </script>
  </body>
</html>

I tested in FF3.5, moving to IE8 now. And it works fine in IE8 too. What browser are you using?

Adding to a vector of pair

IMHO, a very nice solution is to use c++11 emplace_back function:

revenue.emplace_back("string", map[i].second);

It just creates a new element in place.

How can I solve the error LNK2019: unresolved external symbol - function?

I just ran into this problem in Visual Studio 2013. Apparently now, having two projects in the same solution and setting the the dependencies is not enough. You need to add a project reference between them. To do that:

  1. Right-click on the project in the solution explore
  2. Click Add => References...
  3. Click the Add New Reference button
  4. Check the boxes for the projects that this project relies on
  5. Click OK

How to filter (key, value) with ng-repeat in AngularJs?

Although this question is rather old, I'd like to share my solution for angular 1 developers. The point is to just reuse the original angular filter, but transparently passing any objects as an array.

app.filter('objectFilter', function ($filter) {
    return function (items, searchToken) {
        // use the original input
        var subject = items;

        if (typeof(items) == 'object' && !Array.isArray(items)) {
            // or use a wrapper array, if we have an object
            subject = [];

            for (var i in items) {
                subject.push(items[i]);
            }
        }

        // finally, apply the original angular filter
        return $filter('filter')(subject, searchToken);
    }
});

use it like this:

<div>
    <input ng-model="search" />
</div>
<div ng-repeat="item in test | objectFilter : search">
    {{item | json}}
</div>

here is a plunker

How to build a DataTable from a DataGridView?

I don't know anything provided by the Framework (beyond what you want to avoid) that would do what you want but (as I suspect you know) it would be pretty easy to create something simple yourself:

private DataTable GetDataTableFromDGV(DataGridView dgv) {
    var dt = new DataTable();
    foreach (DataGridViewColumn column in dgv.Columns) {
        if (column.Visible) {
            // You could potentially name the column based on the DGV column name (beware of dupes)
            // or assign a type based on the data type of the data bound to this DGV column.
            dt.Columns.Add();
        }
    }

    object[] cellValues = new object[dgv.Columns.Count];
    foreach (DataGridViewRow row in dgv.Rows) {
        for (int i = 0; i < row.Cells.Count; i++) {
            cellValues[i] = row.Cells[i].Value;
        }
        dt.Rows.Add(cellValues);
    }

    return dt;
}

Looping through dictionary object

One way is to loop through the keys of the dictionary, which I recommend:

foreach(int key in sp.Keys)
    dynamic value = sp[key];

Another way, is to loop through the dictionary as a sequence of pairs:

foreach(KeyValuePair<int, dynamic> pair in sp)
{
    int key = pair.Key;
    dynamic value = pair.Value;
}

I recommend the first approach, because you can have more control over the order of items retrieved if you decorate the Keys property with proper LINQ statements, e.g., sp.Keys.OrderBy(x => x) helps you retrieve the items in ascending order of the key. Note that Dictionary uses a hash table data structure internally, therefore if you use the second method the order of items is not easily predictable.

Update (01 Dec 2016): replaced vars with actual types to make the answer more clear.