Programs & Examples On #Anonymize

Loading and parsing a JSON file with multiple JSON objects

You have a JSON Lines format text file. You need to parse your file line by line:

import json

data = []
with open('file') as f:
    for line in f:

Each line contains valid JSON, but as a whole, it is not a valid JSON value as there is no top-level list or object definition.

Note that because the file contains JSON per line, you are saved the headaches of trying to parse it all in one go or to figure out a streaming JSON parser. You can now opt to process each line separately before moving on to the next, saving memory in the process. You probably don't want to append each result to one list and then process everything if your file is really big.

If you have a file containing individual JSON objects with delimiters in-between, use How do I use the 'json' module to read in one JSON object at a time? to parse out individual objects using a buffered method.

Node.js heap out of memory

I just want to add that in some systems, even increasing the node memory limit with --max-old-space-size, it's not enough and there is an OS error like this:

terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
Aborted (core dumped)

In this case, probably is because you reached the max mmap per process.

You can check the max_map_count by running

sysctl vm.max_map_count

and increas it by running

sysctl -w vm.max_map_count=655300

and fix it to not be reset after a reboot by adding this line


in /etc/sysctl.conf file.

Check here for more info.

A good method to analyse the error is by run the process with strace

strace node --max-old-space-size=128000 my_memory_consuming_process.js

Line Break in XML?

  <title>Song Tigle</title>
    <line>The is the very first line</line>
    <line>Number two and I'm still feeling fine</line>
    <line>Number three and a pattern begins</line>
    <line>Add lines like this and everyone wins!</line>

(Sung to the tune of Home on the Range)

If it was mine I'd wrap the choruses and verses in XML elements as well.

SQL : BETWEEN vs <= and >=

They are the same.

One thing to be careful of, is if you are using this against a DATETIME, the match for the end date will be the beginning of the day:

<= 20/10/2009

is not the same as:

<= 20/10/2009 23:59:59

(it would match against <= 20/10/2009 00:00:00.000)

angular.js ng-repeat li items with html content

ng-bind-html-unsafe is deprecated from 1.2. The correct answer should be currently:

HTML-side: (the same as the accepted answer stated):

<div ng-app ng-controller="MyCtrl">
      <li ng-repeat=" opt in opts" ng-bind-html-unsafe="opt.text">
        {{ opt.text }}


But in the controller-side:

myApp.controller('myCtrl', ['$scope', '$sce', function($scope, $sce) {
// ...
   $ { 
      opt = $sce.trustAsHtml(opt);

Access item in a list of lists

You can use itertools.cycle:

>>> from itertools import cycle
>>> lis = [[10,13,17],[3,5,1],[13,11,12]]
>>> cyc = cycle((-1, 1))
>>> 50 + sum(x*next(cyc) for x in lis[0])   # lis[0] is [10,13,17]

Here the generator expression inside sum would return something like this:

>>> cyc = cycle((-1, 1))
>>> [x*next(cyc) for x in lis[0]]
[-10, 13, -17]

You can also use zip here:

>>> cyc = cycle((-1, 1))
>>> [x*y for x, y  in zip(lis[0], cyc)]
[-10, 13, -17]

Comment out HTML and PHP together

PHP parser will search your entire code for <?php (or <? if short_open_tag = On), so HTML comment tags have no effect on PHP parser behavior & if you don't want to parse your PHP code, you have to use PHP commenting directives(/* */ or //).

How to get a enum value from string in C#?

With some error handling...

uint key = 0;
string s = "HKEY_LOCAL_MACHINE";
   key = (uint)Enum.Parse(typeof(baseKey), s);
   //unknown string or s is null

"Data too long for column" - why?

With Hibernate you can create your own UserType. So thats what I did for this issue. Something as simple as this:

    public class BytesType implements org.hibernate.usertype.UserType {

         private final int[] SQL_TYPES = new int[] { java.sql.Types.VARBINARY };

There of course is more to implement from extending your own UserType but I just wanted to throw that out there for anyone looking for other methods.

How to redirect in a servlet filter?

Your response object is declared as a ServletResponse. To use the sendRedirect() method, you have to cast it to HttpServletResponse. This is an extended interface that adds methods related to the HTTP protocol.

Bulk insert with SQLAlchemy ORM

SQLAlchemy introduced that in version 1.0.0:

Bulk operations - SQLAlchemy docs

With these operations, you can now do bulk inserts or updates!

For instance (if you want the lowest overhead for simple table INSERTs), you can use Session.bulk_insert_mappings():

loadme = [(1, 'a'),
          (2, 'b'),
          (3, 'c')]
dicts = [dict(bar=t[0], fly=t[1]) for t in loadme]

s = Session()
s.bulk_insert_mappings(Foo, dicts)

Or, if you want, skip the loadme tuples and write the dictionaries directly into dicts (but I find it easier to leave all the wordiness out of the data and load up a list of dictionaries in a loop).

Clicking HTML 5 Video element to play, pause video, breaks play button

I had countless issues doing this but finally came up with a solution that works.

Basically the code below is adding a click handler to the video but ignoring all the clicks on the lower part (0.82 is arbitrary but seems to work on all sizes).


        // get click position 
        var clickY = (e.pageY - $(this).offset().top);
        var height = parseFloat( $(this).height() );

        // avoids interference with controls
        if(y > 0.82*height) return;

        // toggles play / pause
        this.paused ? : this.pause();


Repeat-until or equivalent loop in Python

UNTIL cond

Is equivalent to

while True:
    if cond:

How to set a Header field on POST a form?

Here is what I did in pub/jade

extends layout
block content
      function doThePost() {
        var jqXHR = $.ajax({ 
            , url:<blabla>
            , headers: { 
                'x-custom1': 'blabla'
                , 'x-custom2': 'blabla'
                , 'content-type': 'application/json'
            , data: {
                'id': 123456, blabla
        .done(function(data, status, req) { console.log("done", data, status, req); })
        .fail(function(req, status, err) { console.log("fail", req, status, err); });
    h1= title
    button(onclick='doThePost()') Click

Error in strings.xml file in Android

post your complete string. Though, my guess is there is an apostrophe (') character in your string. replace it with (\') and it will fix the issue. for example,

<string name="terms">
Hey Mr. Android, are you stuck?  Here, I\'ll clear a path for you.  


Select datatype of the field in postgres

run psql -E and then \d student_details

JavaScript Infinitely Looping slideshow with delays?

You are calling setTimeout() ten times in a row, so they all expire almost at the same time. What you actually want is this:

window.onload = function start() {
function slide(repeats) {
    if (repeats > 0) {
            slide(repeats - 1)

This will call slide(10), which will then set the 3-second timeout to call slide(9), which will set timeout to call slide(8), etc. When slide(0) is called, no more timeouts will be set up.

Load HTML page dynamically into div with jQuery

I think this would do it:

<script type="text/javascript" src=""></script>
<script type="text/javascript">

         $("#content").attr("src" , $(this).attr("ref"));


<iframe id="content"></iframe>

<a href="#" ref="page1.html" class="divlink" >Page 1</a><br />
<a href="#" ref="page2.html" class="divlink" >Page 2</a><br />
<a href="#" ref="page3.html" class="divlink" >Page 3</a><br />
<a href="#" ref="page4.html" class="divlink" >Page 4</a><br />
<a href="#" ref="page5.html" class="divlink" >Page 5</a><br />
<a href="#" ref="page6.html" class="divlink" >Page 6</a><br />

By the way if you can avoid Jquery, you can just use the target attribute of <a> element:

<iframe id="content" name="content"></iframe>

<a href="page1.html" target="content" >Page 1</a><br />
<a href="page2.html" target="content" >Page 2</a><br />
<a href="page3.html" target="content" >Page 3</a><br />
<a href="page4.html" target="content" >Page 4</a><br />
<a href="page5.html" target="content" >Page 5</a><br />
<a href="page6.html" target="content" >Page 6</a><br />

How can I fill out a Python string with spaces?

Correct way of doing this would be to use Python's format syntax as described in the official documentation

For this case it would simply be:
which outputs:
'hi '


format_spec ::=  [[fill]align][sign][#][0][width][,][.precision][type]
fill        ::=  <any character>
align       ::=  "<" | ">" | "=" | "^"
sign        ::=  "+" | "-" | " "
width       ::=  integer
precision   ::=  integer
type        ::=  "b" | "c" | "d" | "e" | "E" | "f" | "F" | "g" | "G" | "n" | "o" | "s" | "x" | "X" | "%"

Pretty much all you need to know is there ^.

Update: as of python 3.6 it's even more convenient with literal string interpolation!

foo = 'foobar'
print(f'{foo:10} is great!')
# foobar     is great!

UILabel with text of two different colors

JTAttributedLabel (by mystcolor) lets you use the attributed string support in UILabel under iOS 6 and at the same time its JTAttributedLabel class under iOS 5 through its JTAutoLabel.

Create a button programmatically and set a background image

SWIFT 3 Version of Alex Reynolds' Answer

let image = UIImage(named: "name") as UIImage?
let button = UIButton(type: UIButtonType.custom) as UIButton
button.frame = CGRect(x: 100, y: 100, width: 100, height: 100)
button.setImage(image, for: .normal)
button.addTarget(self, action: Selector("btnTouched:"), for:.touchUpInside)

How do you tell if caps lock is on using JavaScript?

We use getModifierState to check for caps lock, it's only a member of a mouse or keyboard event so we cannot use an onfocus. The most common two ways that the password field will gain focus is with a click in or a tab. We use onclick to check for a mouse click within the input, and we use onkeyup to detect a tab from the previous input field. If the password field is the only field on the page and is auto-focused then the event will not happen until the first key is released, which is ok but not ideal, you really want caps lock tool tips to display once the password field gains focus, but for most cases this solution works like a charm.


<input type="password" id="password" onclick="checkCapsLock(event)" onkeyup="checkCapsLock(event)" />


function checkCapsLock(e) {
  if (e.getModifierState("CapsLock")) {

How do I get the SharedPreferences from a PreferenceActivity in Android?

if you have a checkbox and you would like to fetch it's value ie true / false in any java file--


Context mContext;
boolean checkFlag;


Python list directory, subdirectory, and files

It's just an addition, with this you can get the data into CSV format

import sys,os
    import pandas as pd
    os.system("pip3 install pandas")
root = "/home/kiran/Downloads/MainFolder" # it may have many subfolders and files inside
lst = []
from fnmatch import fnmatch
pattern = "*.csv"      #I want to get only csv files 
pattern = "*.*"        # Note: Use this pattern to get all types of files and folders 
for path, subdirs, files in os.walk(root):
    for name in files:
        if fnmatch(name, pattern):
            lst.append((os.path.join(path, name)))
df = pd.DataFrame({"filePaths":lst})

Best Regular Expression for Email Validation in C#

Email address: RFC 2822 Format
Matches a normal email address. Does not check the top-level domain.
Requires the "case insensitive" option to be ON.


Usage :

bool isEmail = Regex.IsMatch(emailString, @"\A(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?)\Z", RegexOptions.IgnoreCase);

How to determine one year from now in Javascript

You should use getFullYear() instead of getYear(). getYear() returns the actual year minus 1900 (and so is fairly useless).

Thus a date marking exactly one year from the present moment would be:

var oneYearFromNow = new Date();
oneYearFromNow.setFullYear(oneYearFromNow.getFullYear() + 1);

Note that the date will be adjusted if you do that on February 29.

Similarly, you can get a date that's a month from now via getMonth() and setMonth(). You don't have to worry about "rolling over" from the current year into the next year if you do it in December; the date will be adjusted automatically. Same goes for day-of-month via getDate() and setDate().

Web-scraping JavaScript page with Python

I recently used requests_html library to solve this problem.

Their expanded documentation at is pretty good (skip the annotated version at If your use case is basic, you are likely to have some success.

from requests_html import HTMLSession
session = HTMLSession()
response = session.request(method="get",url="")

If you are having trouble rendering the data you need with response.html.render(), you can pass some javascript to the render function to render the particular js object you need. This is copied from their docs, but it might be just what you need:

If script is specified, it will execute the provided JavaScript at runtime. Example:

script = """
    () => {
        return {
            width: document.documentElement.clientWidth,
            height: document.documentElement.clientHeight,
            deviceScaleFactor: window.devicePixelRatio,

Returns the return value of the executed script, if any is provided:

>>> response.html.render(script=script)
{'width': 800, 'height': 600, 'deviceScaleFactor': 1}

In my case, the data I wanted were the arrays that populated a javascript plot but the data wasn't getting rendered as text anywhere in the html. Sometimes its not clear at all what the object names are of the data you want if the data is populated dynamically. If you can't track down the js objects directly from view source or inspect, you can type in "window" followed by ENTER in the debugger console in the browser (Chrome) to pull up a full list of objects rendered by the browser. If you make a few educated guesses about where the data is stored, you might have some luck finding it there. My graph data was under in the console, so in the "script" variable passed to the .render() method quoted above, I used:

return {

R Plotting confidence bands with ggplot


mp <-data.frame(year=1990:2010)
N <- nrow(mp)

mp <- within(mp,
             wav <- rnorm(N)*cos(2*pi*year)+rnorm(N)*sin(2*pi*year)+5
             wow <- rnorm(N)*wav+rnorm(N)*wav^3

m01 <- gls(wow~poly(wav,3), data=mp, correlation = corARMA(p=1))

Get fitted values (the same as m01$fitted)

fit <- predict(m01)

Normally we could use something like predict(..., to get the confidence intervals on the prediction, but gls doesn't provide this capability. We use a recipe similar to the one shown at :

V <- vcov(m01)
X <- model.matrix(~poly(wav,3),data=mp) <- sqrt(diag(X %*% V %*% t(X)))

Put together a "prediction frame":

predframe <- with(mp,data.frame(year,wav,

Now plot with geom_ribbon

(p1 <- ggplot(mp, aes(year, wow))+

year vs wow

It's easier to see that we got the right answer if we plot against wav rather than year:

(p2 <- ggplot(mp, aes(wav, wow))+

wav vs wow

It would be nice to do the predictions with more resolution, but it's a little tricky to do this with the results of poly() fits -- see ?makepredictcall.

Create Carriage Return in PHP String?

There is also the PHP 5.0.2 PHP_EOL constant that is cross-platform !

Stackoverflow reference

Type List vs type ArrayList in Java

List is an interface. It doesn't have methods. When you call a method on a List reference, it in fact calls the method of ArrayList in both cases.

And for the future you can change List obj = new ArrayList<> to List obj = new LinkList<> or other types which implement List interface.

What is "origin" in Git?

I was also confused by this, and below is what I have learned.

When you clone a repository, for example from GitHub:

  • origin is the alias for the URL from which you cloned the repository. Note that you can change this alias.

  • There is one master branch in the remote repository (aliased by origin). There is also another master branch created locally.

Further information can be found from this SO question: Git branching: master vs. origin/master vs. remotes/origin/master

Download File Using jQuery

By stating window.location.href = 'uploads/file.doc'; you show where you store your files. You might of course use .htacess to force the required behaviour for stored files, but this might not always be handful....

It is better to create a server side php-file and place this content in it:

header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.$_REQUEST['f']);

This code will return ANY file as a download without showing where you actually store it.

You open this php-file via window.location.href = 'scripts/this_php_file.php?f=downloaded_file';

Angular (4, 5, 6, 7) - Simple example of slide in out animation on ngIf

Actually the minimum amount of Angular to be used (as requested in the original question) is just adding a class to the DOM element when show variable is true, and perform the animation/transition via CSS.

So your minimum Angular code is this:

<div class="box-opener" (click)="show = !show">
    Open/close the box

<div class="box" [class.opened]="show">
    <!-- Content -->

With this solution, you need to create CSS rules for the transition, something like this:

.box {
    background-color: #FFCC55;
    max-height: 0px;
    overflow-y: hidden;
    transition: ease-in-out 400ms max-height;

.box.opened {
    max-height: 500px;
    transition: ease-in-out 600ms max-height;

If you have retro-browser-compatibility issues, just remember to add the vendor prefixes in the transitions.

See the example here

Go install fails with error: no install location for directory xxx outside GOPATH

For what it's worth, here's my .bash_profile, that works well for me on a mac with Atom, after installing go with Homebrew:

export GOROOT=`go env GOROOT`
export GOPATH=/Users/yy/Projects/go
export GOBIN=$GOPATH/bin

Dynamically add child components in React

You need to pass your components as children, like this:

var App = require('./App.js');
var SampleComponent = require('./SampleComponent.js');
        <SampleComponent name="SomeName"/> 

And then append them in the component's body:

var App = React.createClass({
    render: function() {
        return (
                <h1>App main component! </h1>

You don't need to manually manipulate HTML code, React will do that for you. If you want to add some child components, you just need to change props or state it depends. For example:

var App = React.createClass({

    getInitialState: function(){
        return [
            {id:1,name:"Some Name"}

    addChild: function() {
        // State change will cause component re-render
            {id:2,name:"Another Name"}

    render: function() {
        return (
                <h1>App main component! </h1>
                <button onClick={this.addChild}>Add component</button>
           => (
                        <SampleComponent key={} name={}/>


Read/Parse text file line by line in VBA

You Can use this code to read line by line in text file and You could also check about the first character is "*" then you can leave that..

Public Sub Test()

    Dim ReadData as String

    Open "C:\satheesh\myfile\file.txt" For Input As #1

    Do Until EOF(1) 
       Line Input #1, ReadData 'Adding Line to read the whole line, not only first 128 positions
    If Not Left(ReadData, 1) = "*" then
       '' you can write the variable ReadData into the database or file
    End If 


    Close #1

End Sub

How do I add a newline to a windows-forms TextBox?

The richtextbox also has a "Lines" property that is an array of strings. Each item in this array ends in an implicit line break and will be displayed on its own line.

If your text is static or has an initial value and you are using the designer in Visual Studio you can simply add lines directly there.

How to remove duplicates from Python list and keep order?

> but I don't know how to retrieve the list members from the hash in alphabetical order.

Not really your main question, but for future reference Rod's answer using sorted can be used for traversing a dict's keys in sorted order:

for key in sorted(my_dict.keys()):
   print key, my_dict[key]

and also because tuple's are ordered by the first member of the tuple, you can do the same with items:

for key, val in sorted(my_dict.items()):
    print key, val

How to call MVC Action using Jquery AJAX and then submit form in MVC?

Assuming that your button is in a form, you are not preventing the default behaviour of the button click from happening i.e. Your AJAX call is made in addition to the form submission; what you're very likely seeing is one of

  1. the form submission happens faster than the AJAX call returns
  2. the form submission causes the browser to abort the AJAX request and continues with submitting the form.

So you should prevent the default behaviour of the button click

$('#btnSave').click(function (e) {

    // prevent the default event behaviour    

        url: "/Home/SaveDetailedInfo",
        type: "POST",
        data: JSON.stringify({ 'Options': someData}),
        dataType: "json",
        traditional: true,
        contentType: "application/json; charset=utf-8",
        success: function (data) {

            // perform your save call here

            if (data.status == "Success") {
            } else {
                alert("Error occurs on the Database level!");
        error: function () {
            alert("An error has occured!!!");

Difference between SelectedItem, SelectedValue and SelectedValuePath

SelectedItem is an object. SelectedValue and SelectedValuePath are strings.

for example using the ListBox:

if you say give me listbox1.SelectedValue it will return the text of the currently selected item.

string value = listbox1.SelectedValue;

if you say give me listbox1.SelectedItem it will give you the entire object.

ListItem item = listbox1.SelectedItem;
string value = item.value;

How to plot a histogram using Matplotlib in Python with a list of data?

This is a very round-about way of doing it but if you want to make a histogram where you already know the bin values but dont have the source data, you can use the np.random.randint function to generate the correct number of values within the range of each bin for the hist function to graph, for example:

import numpy as np
import matplotlib.pyplot as plt

data = [np.random.randint(0, 9, *desired y value*), np.random.randint(10, 19, *desired y value*), etc..]
plt.hist(data, histtype='stepfilled', bins=[0, 10, etc..])

as for labels you can align x ticks with bins to get something like this:

#The following will align labels to the center of each bar with bin intervals of 10
plt.xticks([5, 15, etc.. ], ['Label 1', 'Label 2', etc.. ])

Getting the current date in visual Basic 2008

You may just want:

Dim regDate As Date = Date.Today()

Working around MySQL error "Deadlock found when trying to get lock; try restarting transaction"

If you are using InnoDB or any row-level transactional RDBMS, then it is possible that any write transaction can cause a deadlock, even in perfectly normal situations. Larger tables, larger writes, and long transaction blocks will often increase the likelihood of deadlocks occurring. In your situation, it's probably a combination of these.

The only way to truly handle deadlocks is to write your code to expect them. This generally isn't very difficult if your database code is well written. Often you can just put a try/catch around the query execution logic and look for a deadlock when errors occur. If you catch one, the normal thing to do is just attempt to execute the failed query again.

I highly recommend you read this page in the MySQL manual. It has a list of things to do to help cope with deadlocks and reduce their frequency.

Do I need Content-Type: application/octet-stream for file download?


The content-type should be whatever it is known to be, if you know it. application/octet-stream is defined as "arbitrary binary data" in RFC 2046, and there's a definite overlap here of it being appropriate for entities whose sole intended purpose is to be saved to disk, and from that point on be outside of anything "webby". Or to look at it from another direction; the only thing one can safely do with application/octet-stream is to save it to file and hope someone else knows what it's for.

You can combine the use of Content-Disposition with other content-types, such as image/png or even text/html to indicate you want saving rather than display. It used to be the case that some browsers would ignore it in the case of text/html but I think this was some long time ago at this point (and I'm going to bed soon so I'm not going to start testing a whole bunch of browsers right now; maybe later).

RFC 2616 also mentions the possibility of extension tokens, and these days most browsers recognise inline to mean you do want the entity displayed if possible (that is, if it's a type the browser knows how to display, otherwise it's got no choice in the matter). This is of course the default behaviour anyway, but it means that you can include the filename part of the header, which browsers will use (perhaps with some adjustment so file-extensions match local system norms for the content-type in question, perhaps not) as the suggestion if the user tries to save.


Content-Type: application/octet-stream
Content-Disposition: attachment; filename="picture.png"

Means "I don't know what the hell this is. Please save it as a file, preferably named picture.png".

Content-Type: image/png
Content-Disposition: attachment; filename="picture.png"

Means "This is a PNG image. Please save it as a file, preferably named picture.png".

Content-Type: image/png
Content-Disposition: inline; filename="picture.png"

Means "This is a PNG image. Please display it unless you don't know how to display PNG images. Otherwise, or if the user chooses to save it, we recommend the name picture.png for the file you save it as".

Of those browsers that recognise inline some would always use it, while others would use it if the user had selected "save link as" but not if they'd selected "save" while viewing (or at least IE used to be like that, it may have changed some years ago).

Chrome & Safari Error::Not allowed to load local resource: file:///D:/CSS/Style.css

The solution is already answered here above (long ago).

But the implicit question "why does it work in FF and IE but not in Chrome and Safari" is found in the error text "Not allowed to load local resource": Chrome and Safari seem to use a more strict implementation of sandboxing (for security reasons) than the other two (at this time 2011).

This applies for local access. In a (normal) server environment (apache ...) the file would simply not have been found.

What is android:ems attribute in Edit Text?

Taken from:

The em is simply the font size. In an element with a 2in font, 1em thus means 2in. Expressing sizes, such as margins and paddings, in em means they are related to the font size, and if the user has a big font (e.g., on a big screen) or a small font (e.g., on a handheld device), the sizes will be in proportion. Declarations such as 'text-indent: 1.5em' and 'margin: 1em' are extremely common in CSS.

em is basically CSS property for font sizes.

error LNK2005, already defined?

And if you want these translation units to share this variable, define int k; in A.cpp and put extern int k; in B.cpp.

How can I easily add storage to a VirtualBox machine with XP installed?

I am glad you were able to get this done in this manner, but you can (and I did) use the GParted tool for my Windows XP host by following the helpful entry by Eric. To re-iterate/expand on his solution (don't be afraid of the # steps, I'm trying to help newbies here, so there are necessarily more detailed instructions!):

  1. change the size of the virtual hard disk via the VBoxManage modifyhd command, which is well-documented here and in the VirtualBox documentation.

  2. download the GParted-live ( or search the internet for GParted-live ISO. The important part is to get the live (.iso) verison, which is in the form of a bootable .ISO (CD) image.

  3. Mount this new .ISO to the CD virtual drive in the host machine's Storage settings

  4. If necessary/desired, change the boot order in the System settings for the host machine, to boot from CD before Hard Disk (alternatively, you can press F12 when it's booting up, and select the device)

  5. start your VM; if you changed the boot order, it will boot to the GParted-live ISO; otherwise press F12 to do this.

  6. do not be afraid or get too confused/wrapped up in the initial options you are presented; I selected all the defaults (booting to GParted default, default key mapping, language (assuming English - sorry for my non-English friends!), display, etc.). Read it, but just press enter at each prompt. With a Windows VM you should be fine with all the defaults, and if you're not, you're not going to break anything, and the instructions are pretty good about what to do if the defaults don't work.

  7. it will boot to a GUI environment and start the GParted utility. Highlight the c: drive (assuming that's the drive you want to increase the size on) and select resize/move.

  8. change to the new size you want in MB (they abbreviate MiB) - just add the new amount available (represented in the bottom number - MiB following) to the middle number. E.g: I changed mine from like 4000 MiB (e.g., 4GB - my initial size) to 15000 MiB (15 GB) because I'd added 10 GB to my virtual disk. Then click OK.

  9. Click Apply. Once it's done you'll have to reboot - for whatever reason my mouse did not work on the desktop icons on the GUI (I could not click exit) so I just closed the VM window and selected reboot. I did not even have to unmount the ISO, it apparently did it automatically.

  10. Let Windows go through the disk check - remember, you just changed the size outside of Windows, so it has no record of this. This will presumably allow it to update itself with the new info. Once it completes and you log in, you'll likely be told that Windows needs to reboot to use your 'new device' (at least in XP it did for me). Just reboot and you are done!

Convert xlsx file to csv using batch

Try in2csv!


in2csv file.xlsx > file.csv

Format y axis as percent

Jianxun's solution did the job for me but broke the y value indicator at the bottom left of the window.

I ended up using FuncFormatterinstead (and also stripped the uneccessary trailing zeroes as suggested here):

import pandas as pd
import numpy as np
from matplotlib.ticker import FuncFormatter

df = pd.DataFrame(np.random.randn(100,5))

ax = df.plot()
ax.yaxis.set_major_formatter(FuncFormatter(lambda y, _: '{:.0%}'.format(y))) 

Generally speaking I'd recommend using FuncFormatter for label formatting: it's reliable, and versatile.

enter image description here

Format Date/Time in XAML in Silverlight

you can also use just


in your datagrid column for date time showing

finally it will be

   <sdk:DataGridTextColumn  Binding="{Binding Path=DeliveryDate,StringFormat=d}" Header="Delivery date" Width="*" />

the out put will look like

enter image description here

How can I show an element that has display: none in a CSS rule?

document.getElementById('mybox').style.display = "block";

Does VBA contain a comment block syntax?

There is no syntax for block quote in VBA. The work around is to use the button to quickly block or unblock multiple lines of code.

inline conditionals in angular.js

If I understood you well I think you have two ways of doing it.

First you could try ngSwitch and the second possible way would be creating you own filter. Probably ngSwitch is the right aproach but if you want to hide or show inline content just using {{}} filter is the way to go.

Here is a fiddle with a simple filter as an example.

<div ng-app="exapleOfFilter">
  <div ng-controller="Ctrl">
    <input ng-model="greeting" type="greeting">

angular.module('exapleOfFilter', []).
  filter('isHello', function() {
    return function(input) {
      // conditional you want to apply
      if (input === 'hello') {
        return input;
      return '';

function Ctrl($scope) {
  $scope.greeting = 'hello';

Safari 3rd party cookie iframe trick no longer working?

Here's some code that I use. I found that if I set any cookie from my site, then cookies magically work in the iframe from then on.

 if (isset($_GET['setdefaultcookie'])) {
        // top level page, set default cookie then redirect back to canvas page
        setcookie ('default',"1",0,"/");
        $url = substr($_SERVER['REQUEST_URI'],strrpos($_SERVER['REQUEST_URI'],"/")+1);
        $url = str_replace("setdefaultcookie","defaultcookieset",$url);
        $url = $facebookapp->getCanvasUrl($url);
        echo "<html>\n<body>\n<script>\ntop.location.href='".$url."';\n</script></body></html>";
    } else if ((!isset($_COOKIE['default'])) && (!isset($_GET['defaultcookieset']))) {
        // no default cookie, so we need to redirect to top level and set
        $url = $_SERVER['REQUEST_URI'];
        if (strpos($url,"?") === false) $url .= "?";
        else $url .= "&";
        $url .= "setdefaultcookie=1";
        echo "<html>\n<body>\n<script>\ntop.location.href='".$url."';\n</script></body></html>";

app-release-unsigned.apk is not signed

In tool window bar select Build Variants Change Build Variant from Release to Debug

Google Maps how to Show city or an Area outline

so I have a solution that isn't perfect but it worked for me. Use the polygon example from Google, and use the pinpoint on Google Maps to get lat & long locations.

Calgary pinpoint

I used what I call "ocular copy & paste" where you look at the screen and then write in the numbers you want ;-)

  #map {
    height: 500px;

// This example creates a simple polygon representing the host city of the 
// Greatest Outdoor Show On Earth.

 function initMap() {
   var map = new google.maps.Map(document.getElementById('map'), {
      zoom: 9,
      center: {lat: 51.039, lng: -114.204},
      mapTypeId: 'terrain'

    // Define the LatLng coordinates for the polygon's path.
    var triangleCoords = [
      {lat: 51.183, lng: -114.234},
      {lat: 51.154, lng: -114.235},
      {lat: 51.156, lng: -114.261},
      {lat: 51.104, lng: -114.259},
      {lat: 51.106, lng: -114.261},
      {lat: 51.102, lng: -114.272},
      {lat: 51.081, lng: -114.271},
      {lat: 51.081, lng: -114.234},
      {lat: 51.009, lng: -114.236},
      {lat: 51.008, lng: -114.141},
      {lat: 50.995, lng: -114.142},
      {lat: 50.998, lng: -114.160},
      {lat: 50.984, lng: -114.163},
      {lat: 50.987, lng: -114.141},
      {lat: 50.979, lng: -114.141},
      {lat: 50.921, lng: -114.141},
      {lat: 50.921, lng: -114.210},
      {lat: 50.893, lng: -114.210},
      {lat: 50.892, lng: -114.140},
      {lat: 50.888, lng: -114.139},
      {lat: 50.878, lng: -114.094},
      {lat: 50.878, lng: -113.994},
      {lat: 50.840, lng: -113.954},
      {lat: 50.854, lng: -113.905},
      {lat: 50.922, lng: -113.906},
      {lat: 50.935, lng: -113.877},
      {lat: 50.943, lng: -113.877},
      {lat: 50.955, lng: -113.912},
      {lat: 51.183, lng: -113.910}

    // Construct the polygon.
    var bermudaTriangle = new google.maps.Polygon({
      paths: triangleCoords,
      strokeColor: '#FF0000',
      strokeOpacity: 0.8,
      strokeWeight: 2,
      fillColor: '#FF0000',
      fillOpacity: 0.35

<div id="map"></div>
<script async defer src="">

This gets you the outline for Calgary. I've attached an image here.

Check if a String is in an ArrayList of Strings

    List list1 = new ArrayList();

    List list2 = new ArrayList();
    list2.add("five"); x -> !list1.contains(x) ).forEach(x -> System.out.println(x));

The output is:


HttpWebRequest using Basic authentication

If you can use the WebClient class, using basic authentication becomes simple:

var client = new WebClient {Credentials = new NetworkCredential("user_name", "password")};
var response = client.DownloadString("");

Get the position of a div/span tag

As Alex noted you can use jQuery offset() to get the position relative to the document flow. Use position() for its x,y coordinates relative to the parent.

EDIT: Switched document.ready for window.load because load waits for all of the elements so you get their size instead of simply preparing the DOM. In my experience, load results in fewer incorrectly Javascript positioned elements.

  // Log the position with jQuery
  var position = $('#myDivInQuestion').position();
  console.log('X: ' + position.left + ", Y: " + );

How do I remove the non-numeric character from a string in java?

Another regex solution:

string.replace(/\D/g,'');  //remove the non-Numeric

Similarly, you can

string.replace(/\W/g,'');  //remove the non-alphaNumeric

In RegEX, the symbol '\' would make the letter following it a template: \w -- alphanumeric, and \W - Non-AlphaNumeric, negates when you capitalize the letter.

How to remove class from all elements jquery


How do I set vertical space between list items?

<br>between <li></li> line entries seems to work perfectly well in all web browsers that I've tried, but it fails to pass the on-line W3C CSS3 checker. It gives me precisely the line spacing I am after. As far as I am concerned, since it undoubtedly works, I am persisting in using it, whatever W3C says, until someone can come up with a good legal alternative.

In Tkinter is there any way to make a widget not visible?

For someone who hate OOP like me (This is based on Bryan Oakley's answer)

import tkinter as tk

def show_label():

def hide_label():

root = tk.Tk()
frame1 = tk.Frame(root)

label1 = tk.Label(root, text="Hello, world")

button1 = tk.Button(root, text="Click to hide label",command=hide_label)
button2 = tk.Button(root, text="Click to show label", command=show_label)


Jquery, Clear / Empty all contents of tbody element?




    <tbody id="tbodyid">

Works for me

How do I capture the output into a variable from an external process in PowerShell?

I use the following:

Function GetProgramOutput([string]$exe, [string]$arguments)
    $process = New-Object -TypeName System.Diagnostics.Process
    $process.StartInfo.FileName = $exe
    $process.StartInfo.Arguments = $arguments
    $process.StartInfo.UseShellExecute = $false
    $process.StartInfo.RedirectStandardOutput = $true
    $process.StartInfo.RedirectStandardError = $true
    $output = $process.StandardOutput.ReadToEnd()   
    $err = $process.StandardError.ReadToEnd()
$exe = "C:\Program Files\7-Zip\7z.exe"
$arguments = "i"
$runResult = (GetProgramOutput $exe $arguments)
$stdout = $runResult[-2]
$stderr = $runResult[-1]
[System.Console]::WriteLine("Standard out: " + $stdout)
[System.Console]::WriteLine("Standard error: " + $stderr)

What does "hashable" mean in Python?

From the Python glossary:

An object is hashable if it has a hash value which never changes during its lifetime (it needs a __hash__() method), and can be compared to other objects (it needs an __eq__() or __cmp__() method). Hashable objects which compare equal must have the same hash value.

Hashability makes an object usable as a dictionary key and a set member, because these data structures use the hash value internally.

All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all compare unequal, and their hash value is their id().

The forked VM terminated without saying properly goodbye. VM crash or System.exit called

This will work definitely.....

Add the below lines in the POM file and give a build.


C++ cout hex values?

std::hex gets you the hex formatting, but it is a stateful option, meaning you need to save and restore state or it will impact all future output.

Naively switching back to std::dec is only good if that's where the flags were before, which may not be the case, particularly if you're writing a library.

#include <iostream>
#include <ios>


std::ios_base::fmtflags f( cout.flags() );  // save flags state
std::cout << std::hex << a;
cout.flags( f );  // restore flags state

This combines Greg Hewgill's answer and info from another question.

Print the address or pointer for value in C

Since you already seem to have solved the basic pointer address display, here's how you would check the address of a double pointer:

char **a;
char *b;
char c = 'H';

b = &c;
a = &b;

You would be able to access the address of the double pointer a by doing:

printf("a points at this memory location: %p", a);
printf("which points at this other memory location: %p", *a);

Is arr.__len__() the preferred way to get the length of an array in Python?

The preferred way to get the length of any python object is to pass it as an argument to the len function. Internally, python will then try to call the special __len__ method of the object that was passed.

Styling Google Maps InfoWindow

You can modify the whole InfoWindow using jquery alone...

var popup = new google.maps.InfoWindow({
    content:'<p id="hook">Hello World!</p>'

Here the <p> element will act as a hook into the actual InfoWindow. Once the domready fires, the element will become active and accessible using javascript/jquery, like $('#hook').parent().parent().parent().parent().

The below code just sets a 2 pixel border around the InfoWindow.

google.maps.event.addListener(popup, 'domready', function() {
    var l = $('#hook').parent().parent().parent().siblings();
    for (var i = 0; i < l.length; i++) {
        if($(l[i]).css('z-index') == 'auto') {
            $(l[i]).css('border-radius', '16px 16px 16px 16px');
            $(l[i]).css('border', '2px solid red');

You can do anything like setting a new CSS class or just adding a new element.

Play around with the elements to get what you need...

No notification sound when sending notification from firebase in android

I am able to play notification sound even if I send it from firebase console. To do that you just need to add key "sound" with value "default" in advance option.

What is the maximum characters for the NVARCHAR(MAX)?

The max size for a column of type NVARCHAR(MAX) is 2 GByte of storage.

Since NVARCHAR uses 2 bytes per character, that's approx. 1 billion characters.

Leo Tolstoj's War and Peace is a 1'440 page book, containing about 600'000 words - so that might be 6 million characters - well rounded up. So you could stick about 166 copies of the entire War and Peace book into each NVARCHAR(MAX) column.

Is that enough space for your needs? :-)

Assign variable in if condition statement, good practice or not?

I did it many times. To bypass the JavaScript warning, I add two parens:

if ((result = get_something())) { }

You should avoid it, if you really want to use it, write a comment above it saying what you are doing.

How to get Latitude and Longitude of the mobile device in android?

Above solutions is also correct, but some time if location is null then it crash the app or not working properly. The best way to get Latitude and Longitude of android is:

 Geocoder geocoder;
     String bestProvider;
     List<Address> user = null;
     double lat;
     double lng;

    LocationManager lm = (LocationManager) activity.getSystemService(Context.LOCATION_SERVICE);

     Criteria criteria = new Criteria();
     bestProvider = lm.getBestProvider(criteria, false);
     Location location = lm.getLastKnownLocation(bestProvider);

     if (location == null){
         Toast.makeText(activity,"Location Not found",Toast.LENGTH_LONG).show();
        geocoder = new Geocoder(activity);
        try {
            user = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
        System.out.println(" DDD lat: " +lat+",  longitude: "+lng);

        }catch (Exception e) {

How to install latest version of openssl Mac OS X El Capitan

I can't reproduce your issue running El Cap + Homebrew 1.0.x

Upgrade to Homebrew 1.0.x, which was released late in September. Specific changes were made in the way openssl is linked. The project is on a more robust release schedule now that it's hit 1.0.

brew uninstall openssl
brew update && brew upgrade && brew cleanup && brew doctor

You should fix any issues raised by brew doctor before proceeding.

brew install openssl

Note: Upgrading homebrew will update all your installed packages to their latest versions.

Get model's fields in Django

I know this post is pretty old, but I just cared to tell anyone who is searching for the same thing that there is a public and official API to do this: get_fields() and get_field()


fields = model._meta.get_fields()
my_field = model._meta.get_field('my_field')

How to generate serial version UID in Intellij

Without any plugins:

You just need to enable highlight: (Idea v.2016, 2017 and 2018, previous versions may have same or similar settings)

File -> Settings -> Editor -> Inspections -> Java -> Serialization issues -> Serializable class without 'serialVersionUID' - set flag and click 'OK'. (For Macs, Settings is under IntelliJ IDEA -> Preferences...)

Now, if your class implements Serializable, you will see highlight and alt+Enter on class name will ask you to generate private static final long serialVersionUID.

UPD: a faster way to find this setting - you might use hotkey Ctrl+Shift+A (find action), type Serializable class without 'serialVersionUID' - the first is the one.

How to make a submit out of a <a href...>...</a> link?

Dont forget the "BUTTON" element wich can handle some more HTML inside...

Convert timestamp to date in MySQL query


SELECT strftime("%Y-%d-%m", col_name, 'unixepoch') AS col_name

It will format timestamp in milliseconds to yyyy-mm-dd string.

Android : How to set onClick event for Button in List item of ListView


inside your getView(...) method if you try to start an activity through button onClickListener:

        val intent = Intent(this@CurrentActivity,

Pass the correct pointer for "this"

Resolving instances with ASP.NET Core DI from within ConfigureServices

public void ConfigureServices(IServiceCollection services)

    services.AddDbContext<ConfigurationRepository>(options =>

    services.AddScoped<IConfigurationBL, ConfigurationBL>();
    services.AddScoped<IConfigurationRepository, ConfigurationRepository>();

How to create standard Borderless buttons (like in the design guideline mentioned)?

Look into the theme attributes buttonBarStyle, buttonBarButtonStyle, and borderlessButtonStyle.

Is there a better alternative than this to 'switch on type'?

Create an interface IFooable, then make your A and B classes to implement a common method, which in turn calls the corresponding method you want:

interface IFooable
    public void Foo();

class A : IFooable
    //other methods ...

    public void Foo()

class B : IFooable
    //other methods ...

    public void Foo()

class ProcessingClass
    public void Foo(object o)
        if (o == null)
            throw new NullRefferenceException("Null reference", "o");

        IFooable f = o as IFooable;
        if (f != null)
            throw new ArgumentException("Unexpected type: " + o.GetType());

Note, that it's better to use as instead first checking with is and then casting, as that way you make 2 casts, so it's more expensive.

Java Regex Capturing Groups

This is totally OK.

  1. The first group ( always captures the whole area that is covered by your regular expression. In this case, it's the whole string.
  2. Regular expressions are greedy by default, meaning that the first group captures as much as possible without violating the regex. The (.*)(\\d+) (the first part of your regex) covers the ...QT300 int the first group and the 0 in the second.
  3. You can quickly fix this by making the first group non-greedy: change (.*) to (.*?).

For more info on greedy vs. lazy, check this site.

How to get data out of a Node.js http get request

I think it's too late to answer this question but I faced the same problem recently my use case was to call the paginated JSON API and get all the data from each pagination and append it to a single array.

const https = require('https');
const apiUrl = "";
let finaldata = [];
let someCallBack = function(data){
const getData = function (substr, pageNo=1, someCallBack) {

  let actualUrl = apiUrl + `${substr}&page=${pageNo}`;
  let mydata = []
  https.get(actualUrl, (resp) => {
    let data = '';
    resp.on('data', (chunk) => {
        data += chunk;
    resp.on('end', async () => {
        if (JSON.parse(data).total_pages!==null){
          await getData(substr, pageNo, someCallBack);
  }).on("error", (err) => {
      console.log("Error: " + err.message);

getData("spiderman", pageNo=1, someCallBack);

Like @ackuser mentioned we can use other module but In my use case I had to use the node https. Hoping this will help others.

Is there a way to make npm install (the command) to work behind proxy?

Try to find .npmrc in C:\Users\.npmrc

then open (notepad), write, and save inside :


PS : remove "<" and ">" please !!

How to download files using axios

The trick is to make an invisible anchor tag in the render() and add a React ref allowing to trigger a click once we have the axios response:

class Example extends Component {
    state = {
        ref: React.createRef()

    exportCSV = () => {
        ).then(response => {
            let blob = new Blob([], {type: 'application/octet-stream'})
            let ref = this.state.ref
            ref.current.href = URL.createObjectURL(blob)
   = 'data.csv'

                <a style={{display: 'none'}} href='empty' ref={this.state.ref}>ref</a>
                <button onClick={this.exportCSV}>Export CSV</button>

Here is the documentation: You can find a similar idea here:

Maintain model of scope when changing between views in AngularJS

$rootScope is a big global variable, which is fine for one-off things, or small apps. Use a service if you want to encapsulate your model and/or behavior (and possibly reuse it elsewhere). In addition to the google group post the OP mentioned, see also

Why does multiplication repeats the number several times?

It's the difference between strings and integers. See:

>>> "1" * 9

>>> 1 * 9

Parsing Json rest api response in C#

  1. Create classes that match your data,
  2. then use JSON.NET to convert the JSON data to regular C# objects.

Step 1: a great tool - - the results generated by it are below

Step 2: JToken.Parse(...).ToObject<RootObject>().

public class Meta
    public int code { get; set; }
    public string status { get; set; }
    public string method_name { get; set; }

public class Photos
    public int total_count { get; set; }

public class Storage
    public int used { get; set; }

public class Stats
    public Photos photos { get; set; }
    public Storage storage { get; set; }

public class From
    public string id { get; set; }
    public string first_name { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public List<object> external_accounts { get; set; }
    public string email { get; set; }
    public string confirmed_at { get; set; }
    public string username { get; set; }
    public string admin { get; set; }
    public Stats stats { get; set; }

public class ParticipateUser
    public string id { get; set; }
    public string first_name { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public List<object> external_accounts { get; set; }
    public string email { get; set; }
    public string confirmed_at { get; set; }
    public string username { get; set; }
    public string admin { get; set; }
    public Stats stats { get; set; }

public class ChatGroup
    public string id { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public string message { get; set; }
    public List<ParticipateUser> participate_users { get; set; }

public class Chat
    public string id { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public string message { get; set; }
    public From from { get; set; }
    public ChatGroup chat_group { get; set; }

public class Response
    public List<Chat> chats { get; set; }

public class RootObject
    public Meta meta { get; set; }
    public Response response { get; set; }

__init__ and arguments in Python

In Python:

  • Instance methods: require the self argument.
  • Class methods: take the class as a first argument.
  • Static methods: do not require either the instance (self) or the class (cls) argument.

__init__ is a special function and without overriding __new__ it will always be given the instance of the class as its first argument.

An example using the builtin classmethod and staticmethod decorators:

import sys

class Num:
    max = sys.maxint

    def __init__(self,num):
        self.n = num

    def getn(self):
        return self.n

    def getone():
        return 1

    def getmax(cls):
        return cls.max

myObj = Num(3)
# with the appropriate decorator these should work fine

That said, I would try to use @classmethod/@staticmethod sparingly. If you find yourself creating objects that consist of nothing but staticmethods the more pythonic thing to do would be to create a new module of related functions.

Tainted canvases may not be exported

For security reasons, your local drive is declared to be "other-domain" and will taint the canvas.

(That's because your most sensitive info is likely on your local drive!).

While testing try these workarounds:

  • Put all page related files (.html, .jpg, .js, .css, etc) on your desktop (not in sub-folders).

  • Post your images to a site that supports cross-domain sharing (like Be sure you put your images in dropbox's public folder and also set the cross origin flag when downloading the image (var img=new Image(); img.crossOrigin="anonymous" ...)

  • Install a webserver on your development computer (IIS and PHP web servers both have free editions that work nicely on a local computer).

How to position background image in bottom right corner? (CSS)

Did you try something like:

body {background: url('[url to your image]') no-repeat right bottom;}

Error: Module not specified (IntelliJ IDEA)

this is how I fix this issue my project structure module enter image description here plus button enter image description here import module,and find the module's pom enter image description here
5.make sure you select the module you want to import,then next next finish:) enter image description here

What is the difference between Integrated Security = True and Integrated Security = SSPI?

Using Windows Authentication

To connect to the database server is recommended to use Windows Authentication, commonly known as integrated security. To specify the Windows authentication, you can use any of the following two key-value pairs with the data provider. NET Framework for SQL Server:

 Integrated Security = true;
 Integrated Security = SSPI;

However, only the second works with the data provider .NET Framework OleDb. If you set Integrated Security = true for ConnectionString an exception is thrown.

To specify the Windows authentication in the data provider. NET Framework for ODBC, you should use the following key-value pair.

Trusted_Connection = yes;

Source: MSDN: Working with Connection Strings

How to change the interval time on bootstrap carousel?

       <div class="carousel-inner text-right">
                  <div class="carousel-item active text-center" id="first"  data-interval="1000" >
                    <img src="images/slide-1.gif" alt="slide-1">
                  <div class="carousel-item  text-center" id="second"  data-interval="2000" >
                    <img src="images/slide-2.gif" alt="slide-2">
                  <div class="carousel-item  text-center" id="third"  data-interval="3000" >
                    <img src="images/slide-3.gif" alt="slide-3">
                  <div class="carousel-item text-center" id="four"  data-interval="5000" >
                    <img src="images/slide-4.gif" alt="slide-4">

You can also change different slides.

Android: How to add R.raw to project?

Using IntelliJ Idea:

1) Invalidate Caches, and 2) right click on resources, New Resources directory, type = raw 3) build

note in step 2: I was concerned that simply adding a raw directory wouldn't be enough...

Animate change of view background color on Android

I've found that the implementation used by ArgbEvaluator in the Android source code does best job in transitioning colors. When using HSV, depending on the two colors, the transition was jumping through too many hues for me. But this method's doesn't.

If you are trying to simply animate, use ArgbEvaluator with ValueAnimator as suggested here:

ValueAnimator colorAnimation = ValueAnimator.ofObject(new ArgbEvaluator(), colorFrom, colorTo);
colorAnimation.addUpdateListener(new AnimatorUpdateListener() {

    public void onAnimationUpdate(ValueAnimator animator) {
        view.setBackgroundColor((int) animator.getAnimatedValue());


However, if you are like me and want to tie your transition with some user gesture or other value passed from an input, the ValueAnimator is not of much help (unless your are targeting for API 22 and above, in which case you can use the ValueAnimator.setCurrentFraction() method). When targeting below API 22, wrap the code found in ArgbEvaluator source code in your own method, as shown below:

public static int interpolateColor(float fraction, int startValue, int endValue) {
    int startA = (startValue >> 24) & 0xff;
    int startR = (startValue >> 16) & 0xff;
    int startG = (startValue >> 8) & 0xff;
    int startB = startValue & 0xff;
    int endA = (endValue >> 24) & 0xff;
    int endR = (endValue >> 16) & 0xff;
    int endG = (endValue >> 8) & 0xff;
    int endB = endValue & 0xff;
    return ((startA + (int) (fraction * (endA - startA))) << 24) |
            ((startR + (int) (fraction * (endR - startR))) << 16) |
            ((startG + (int) (fraction * (endG - startG))) << 8) |
            ((startB + (int) (fraction * (endB - startB))));

And use it however you wish.

href="javascript:" vs. href="javascript:void(0)"

It does not cause problems but it's a trick to do the same as PreventDefault

when you're way down in the page and an anchor as:

<a href="#" onclick="fn()">click here</a>

you will jump to the top and the URL will have the anchor # as well, to avoid this we simply return false; or use javascript:void(0);

regarding your examples

<a onclick="fn()">Does not appear as a link, because there's no href</a>

just do a {text-decoration:underline;} and you will have "link a-like"

<a href="javascript:void(0)" onclick="fn()">fn is called</a>
<a href="javascript:" onclick="fn()">fn is called too!</a>

it's ok, but in your function at the end, just return false; to prevent the default behavior, you don't need to do anything more.

Testing web application on Mac/Safari when I don't own a Mac offers a browser sandbox in which containerised virtual machines run browser sessions for you. I tried it with Safari on my Windows development machine and it seems to work very well.

html select option separator

I elected to conditionally alternate color and background. Setting a sort order and with vue.js, I did something like this:

    .altgroup_1 {background:gray; color:white;}
    .altgroup_2{background:white; color:black;}

<option :class = {
    'altgroup_1': (country.sort_order > 25),
    'altgroup_2': (country.sort_order > 50 }"
    value="{{ country.iso_short }}">
    {{ country.short_name }}

How would you count occurrences of a string (actually a char) within a string?

            var conditionalStatement = conditionSetting.Value;

            //order of replace matters, remove == before =, incase of ===
            conditionalStatement = conditionalStatement.Replace("==", "~").Replace("!=", "~").Replace('=', '~').Replace('!', '~').Replace('>', '~').Replace('<', '~').Replace(">=", "~").Replace("<=", "~");

            var listOfValidConditions = new List<string>() { "!=", "==", ">", "<", ">=", "<=" };

            if (conditionalStatement.Count(x => x == '~') != 1)
                result.InvalidFieldList.Add(new KeyFieldData(batch.DECurrentField, "The IsDoubleKeyCondition does not contain a supported conditional statement. Contact System Administrator."));
                result.Status = ValidatorStatus.Fail;
                return result;

Needed to do something similar to test conditional statements from a string.

Replaced what i was looking for with a single character and counted the instances of the single character.

Obviously the single character you're using will need to be checked to not exist in the string before this happens to avoid incorrect counts.

How to set specific window (frame) size in java swing?

Most layout managers work best with a component's preferredSize, and most GUI's are best off allowing the components they contain to set their own preferredSizes based on their content or properties. To use these layout managers to their best advantage, do call pack() on your top level containers such as your JFrames before making them visible as this will tell these managers to do their actions -- to layout their components.

Often when I've needed to play a more direct role in setting the size of one of my components, I'll override getPreferredSize and have it return a Dimension that is larger than the super.preferredSize (or if not then it returns the super's value).

For example, here's a small drag-a-rectangle app that I created for another question on this site:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MoveRect extends JPanel {
   private static final int RECT_W = 90;
   private static final int RECT_H = 70;
   private static final int PREF_W = 600;
   private static final int PREF_H = 300;
   private static final Color DRAW_RECT_COLOR =;
   private static final Color DRAG_RECT_COLOR = new Color(180, 200, 255);
   private Rectangle rect = new Rectangle(25, 25, RECT_W, RECT_H);
   private boolean dragging = false;
   private int deltaX = 0;
   private int deltaY = 0;

   public MoveRect() {
      MyMouseAdapter myMouseAdapter = new MyMouseAdapter();

   protected void paintComponent(Graphics g) {
      if (rect != null) {
         Color c = dragging ? DRAG_RECT_COLOR : DRAW_RECT_COLOR;
         Graphics2D g2 = (Graphics2D) g;

   public Dimension getPreferredSize() {
      return new Dimension(PREF_W, PREF_H);

   private class MyMouseAdapter extends MouseAdapter {

      public void mousePressed(MouseEvent e) {
         Point mousePoint = e.getPoint();
         if (rect.contains(mousePoint)) {
            dragging = true;
            deltaX = rect.x - mousePoint.x;
            deltaY = rect.y - mousePoint.y;

      public void mouseReleased(MouseEvent e) {
         dragging = false;

      public void mouseDragged(MouseEvent e) {
         Point p2 = e.getPoint();
         if (dragging) {
            int x = p2.x + deltaX;
            int y = p2.y + deltaY;
            rect = new Rectangle(x, y, RECT_W, RECT_H);

   private static void createAndShowGui() {
      MoveRect mainPanel = new MoveRect();

      JFrame frame = new JFrame("MoveRect");

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {

Note that my main class is a JPanel, and that I override JPanel's getPreferredSize:

public class MoveRect extends JPanel {
   //.... deleted constants

   private static final int PREF_W = 600;
   private static final int PREF_H = 300;

   //.... deleted fields and constants

   //... deleted methods and constructors

   public Dimension getPreferredSize() {
      return new Dimension(PREF_W, PREF_H);

Also note that when I display my GUI, I place it into a JFrame, call pack(); on the JFrame, set its position, and then call setVisible(true); on my JFrame:

   private static void createAndShowGui() {
      MoveRect mainPanel = new MoveRect();

      JFrame frame = new JFrame("MoveRect");

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {

VBA procedure to import csv file into access

Your file seems quite small (297 lines) so you can read and write them quite quickly. You refer to Excel CSV, which does not exists, and you show space delimited data in your example. Furthermore, Access is limited to 255 columns, and a CSV is not, so there is no guarantee this will work

Sub StripHeaderAndFooter()
Dim fs As Object ''FileSystemObject
Dim tsIn As Object, tsOut As Object ''TextStream
Dim sFileIn As String, sFileOut As String
Dim aryFile As Variant

    sFileIn = "z:\docs\FileName.csv"
    sFileOut = "z:\docs\FileOut.csv"

    Set fs = CreateObject("Scripting.FileSystemObject")
    Set tsIn = fs.OpenTextFile(sFileIn, 1) ''ForReading

    sTmp = tsIn.ReadAll

    Set tsOut = fs.CreateTextFile(sFileOut, True) ''Overwrite
    aryFile = Split(sTmp, vbCrLf)

    ''Start at line 3 and end at last line -1
    For i = 3 To UBound(aryFile) - 1
        tsOut.WriteLine aryFile(i)


    DoCmd.TransferText acImportDelim, , "NewCSV", sFileOut, False
End Sub

Edit re various comments

It is possible to import a text file manually into MS Access and this will allow you to choose you own cell delimiters and text delimiters. You need to choose External data from the menu, select your file and step through the wizard.

About importing and linking data and database objects -- Applies to: Microsoft Office Access 2003

Introduction to importing and exporting data -- Applies to: Microsoft Access 2010

Once you get the import working using the wizards, you can save an import specification and use it for you next DoCmd.TransferText as outlined by @Olivier Jacot-Descombes. This will allow you to have non-standard delimiters such as semi colon and single-quoted text.

Get device information (such as product, model) from adb command

Why don't you try to grep the return of your command ? Something like :

adb devices -l | grep 123abc12

It should return only the line you want to.

check output from CalledProcessError

Thanx @krd, I am using your error catch process, but had to update the print and except statements. I am using Python 2.7.6 on Linux Mint 17.2.

Also, it was unclear where the output string was coming from. My update:

import subprocess

# Output returned in error handler
    print("Ping stdout output on success:\n" + 
           subprocess.check_output(["ping", "-c", "2", "-w", "2", ""]))
except subprocess.CalledProcessError as e:
    print("Ping stdout output on error:\n" + e.output)

# Output returned normally
    print("Ping stdout output on success:\n" + 
           subprocess.check_output(["ping", "-c", "2", "-w", "2", ""]))
except subprocess.CalledProcessError as e:
    print("Ping stdout output on error:\n" + e.output)

I see an output like this:

Ping stdout output on error:
PING ( 56(84) bytes of data.

--- ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1007ms

Ping stdout output on success:
PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=59 time=37.8 ms
64 bytes from icmp_seq=2 ttl=59 time=38.8 ms

--- ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 37.840/38.321/38.802/0.481 ms

How do I calculate tables size in Oracle

For sub partitioned tables and indexes we can use the following query

    SELECT owner, table_name, ROUND(sum(bytes)/1024/1024/1024, 2) GB
    (SELECT segment_name table_name, owner, bytes
     FROM dba_segments
     SELECT i.table_name, i.owner, s.bytes
     FROM dba_indexes i, dba_segments s
     WHERE s.segment_name = i.index_name
     AND   s.owner = i.owner
     SELECT l.table_name, l.owner, s.bytes
     FROM dba_lobs l, dba_segments s
     WHERE s.segment_name = l.segment_name
     AND   s.owner = l.owner
     AND   s.segment_type = 'LOBSEGMENT'
     SELECT l.table_name, l.owner, s.bytes
     FROM dba_lobs l, dba_segments s
     WHERE s.segment_name = l.index_name
     AND   s.owner = l.owner
     AND   s.segment_type = 'LOBINDEX')
    WHERE owner in UPPER('&owner')
    GROUP BY table_name, owner
    HAVING SUM(bytes)/1024/1024 > 10  /* Ignore really small tables */
    ORDER BY SUM(bytes) DESC

Sending JSON to PHP using ajax

If you want to get the values via the $_POST variable then you should not specify the contentType as "application/json" but rather use the default "application/x-www-form-urlencoded; charset=UTF-8":


var person = { name: "John" };

    //contentType: "application/json", // php://input
    contentType: "application/x-www-form-urlencoded; charset=UTF-8", // $_POST
    dataType : "json",
    method: "POST",
    url: "http://localhost/test/test.php",
    data: {data: person}
.done(function(data) {  
    console.log("test: ", data);
.fail(function(data) {
    console.log("error: ", data);



// $_POST

$jsonString = $_POST['data'];

$newJsonString = json_encode($jsonString);
header('Content-Type: application/json');
echo $newJsonString;

Else if you want to send a JSON from JavaScript to PHP:


var person = { name: "John" };

    contentType: "application/json", // php://input
    //contentType: "application/x-www-form-urlencoded; charset=UTF-8", // $_POST
    dataType : "json",
    method: "POST",
    url: "http://localhost/test/test.php",
    data: person
.done(function(data) {  
    console.log("test: ", data);
.fail(function(data) {
    console.log("error: ", data);



$jsonString = file_get_contents("php://input");
$phpObject = json_decode($jsonString);

$newJsonString = json_encode($phpObject);
header('Content-Type: application/json');
echo $newJsonString;

Run JavaScript when an element loses focus

You're looking for the onblur event. Look here, for more details.

Get individual query parameters from Uri

This should work:

string url = "";
string querystring = url.Substring(url.IndexOf('?'));
System.Collections.Specialized.NameValueCollection parameters = 

According to MSDN. Not the exact collectiontype you are looking for, but nevertheless useful.

Edit: Apparently, if you supply the complete url to ParseQueryString it will add '' as the first key of the collection. Since that is probably not what you want, I added the substring to get only the relevant part of the url.

Mongoose query where value is not null

Hello guys I am stucked with this. I've a Document Profile who has a reference to User,and I've tried to list the profiles where user ref is not null (because I already filtered by rol during the population), but after googleing a few hours I cannot figure out how to get this. I have this query:

const profiles = await Profile.find({ user: {$exists: true,  $ne: null }})
                            .sort( {_id: -1} )
                            .skip( skip )
                                path: 'user',
                                match: { role: {$eq: customer}},
                                select: '-password -verified -_id -__v'


And I get this result, how can I remove from the results the user:null colletions? . I meant, I dont want to get the profile when user is null (the role does not match).
    "code": 200,
    "profiles": [
            "description": null,
            "province": "West Midlands",
            "country": "UK",
            "postal_code": "83000",
            "user": null
            "description": null,

            "province": "Madrid",
            "country": "Spain",
            "postal_code": "43000",
            "user": {
                "role": "customer",
                "name": "pedrita",
                "email": "[email protected]",
                "created_at": "2020-06-05T11:05:36.450Z"
    "page": 1

Thanks in advance.

iframe to Only Show a Certain Part of the Page

An <iframe> gives you a complete window to work with. The most direct way to do what you want is to have your server give you a complete page that only contains the fragment you want to show.

As an alternative, you could just use a simple <div> and use the jQuery "load" function to load the whole page and pluck out just the section you want:

$('#target-div').load(' #portfolio-sports');

There may be other things you need to do, and a significant difference is that the content will become part of the main page instead of being segregated into a separate window.

A potentially dangerous Request.Form value was detected from the client

For ASP.NET 4.0, you can allow markup as input for specific pages instead of the whole site by putting it all in a <location> element. This will make sure all your other pages are safe. You do NOT need to put ValidateRequest="false" in your .aspx page.

  <location path="MyFolder/.aspx">
      <pages validateRequest="false" />
      <httpRuntime requestValidationMode="2.0" />

It is safer to control this inside your web.config, because you can see at a site level which pages allow markup as input.

You still need to programmatically validate input on pages where request validation is disabled.

Why em instead of px?

It is wrong to say that one is a better choice than the other (or both wouldn't have been given their own purpose in the spec). It may even be worth noting that StackOverflow makes extensive use of px units. It is not the poor choice Spoike was told it was.

Definition of units

  • px is an absolute unit of measurement (like in, pt, or cm) that also happens to be 1/96 of an in unit (more on why later). Because it is an absolute measurement, it may be used any time you want to define something to be a particular size, rather than being proportional to something else like the size of the browser window or the font size.

    Like all the other absolute units, px units don't scale according to the width of the browser window. Thus, if your entire page design uses absolute units such as px rather than %, it won't adapt to the width of the browser. This is not inherently good or bad, just a choice that the designer needs to make between adhering to an exact size and being inflexible versus stretching but in the process not adhering to an exact size. It would be typical for a site to have a mix of fixed-size and flexible-sized objects.

    Fixed size elements often need to be incorporated into the page - such as advertising banners, logos or icons. This ensures you almost always need at least some px-based measurements in a design. Images, for example, will (by default) be scaled such that each pixel is 1*px* in size, so if you are designing around an image you'll need px units. It is also very useful for precise font sizing, and for border widths, where due to rounding it makes the most sense to use px units for the majority of screens.

    All absolute measurements are rigidly related to each other; that is, 1in is always 96px, just as 1in is always 72pt. (Note that 1in is almost never actually a physical inch when talking about screen-based media). All absolute measurements assume a nominal screen resolution of 96ppi and a nominal viewing distance of a desktop monitor, and on such a screen one px will be equal to one physical pixel on the screen and one in will be equal to 96 physical pixels. On screens that differ significantly in either pixel density or viewing distance, or if the user has zoomed the page using the browser's zoom function, px will no longer necessarily relate to physical pixels.

  • em is not an absolute unit - it is a unit that is relative to the currently chosen font size. Unless you have overridden font style by setting your font size with an absolute unit (such as px or pt), this will be affected by the choice of fonts in the user's browser or OS if they have made one, so it does not make sense to use em as a general unit of length except where you specifically want it to scale as the font size scales.

    Use em when you specifically want the size of something to depend on the current font size.

  • % is also a relative unit, in this case, relative to either the height or width of a parent element. They are a good alternative to px units for things like the total width of a design if your design does not rely on specific pixel sizes to set its size.

    Using % units in your design allows your design to adapt to the width of the screen/device, whereas using an absolute unit such as px does not.

error: unknown type name ‘bool’

C90 does not support the boolean data type.

C99 does include it with this include:

#include <stdbool.h>

What is the email subject length limit?

RFC2322 states that the subject header "has no length restriction"

but to produce long headers but you need to split it across multiple lines, a process called "folding".

subject is defined as "unstructured" in RFC 5322

here's some quotes ([...] indicate stuff i omitted)

3.6.5. Informational Fields
  The informational fields are all optional.  The "Subject:" and
  "Comments:" fields are unstructured fields as defined in section
  2.2.1, [...]

2.2.1. Unstructured Header Field Bodies
  Some field bodies in this specification are defined simply as
  "unstructured" (which is specified in section 3.2.5 as any printable
  US-ASCII characters plus white space characters) with no further
  restrictions.  These are referred to as unstructured field bodies.
  Semantically, unstructured field bodies are simply to be treated as a
  single line of characters with no further processing (except for
  "folding" and "unfolding" as described in section 2.2.3).

2.2.3  [...]  An unfolded header field has no length restriction and
  therefore may be indeterminately long.

How to assert greater than using JUnit Assert?

As I recognize, at the moment, in JUnit, the syntax is like this:

AssertTrue(Long.parseLong(previousTokenValues[1]) > Long.parseLong(currentTokenValues[1]), "your fail message ");

Means that, the condition is in front of the message.

How to remove time portion of date in C# in DateTime object only?

This could be simply done this way:

var dateOnly = new DateTime(dateTime.Year, dateTime.Month, dateTime.Day)

Use the XmlInclude or SoapInclude attribute to specify types that are not known statically

I agree with bizl

public abstract class WarningsType{ }

also if you need to apply this included class to an object item you can do like that

[System.Xml.Serialization.XmlElementAttribute("Warnings", typeof(WarningsType))]
public object[] Items
        return this.itemsField;
        this.itemsField = value;

Read a text file line by line in Qt

Here's the example from my code. So I will read a text from 1st line to 3rd line using readLine() and then store to array variable and print into textfield using for-loop :

QFile file("file.txt");

    if(! | QIODevice::Text))

    QTextStream in(&file);
    QString line[3] = in.readLine();
    for(int i=0; i<3; i++)

Composer: file_put_contents(./composer.json): failed to open stream: Permission denied

In my case, .composer was owned by root, so I did sudo rm -fr .composer and then my global require worked.

Be warned! You don't wanna use that command if you are not sure what you are doing.

How do I get the resource id of an image if I know its name?

With something like this:

String mDrawableName = "myappicon";
int resID = getResources().getIdentifier(mDrawableName , "drawable", getPackageName());

Python Git Module experiences?

Maybe it helps, but Bazaar and Mercurial are both using dulwich for their Git interoperability.

Dulwich is probably different than the other in the sense that's it's a reimplementation of git in python. The other might just be a wrapper around Git's commands (so it could be simpler to use from a high level point of view: commit/add/delete), it probably means their API is very close to git's command line so you'll need to gain experience with Git.

Dart: mapping a list (

Yes, You can do it this way too

 List<String> listTab = new List();
 map.forEach((key, val) {

 //your widget//
 bottom: new TabBar(
  controller: _controller,
  isScrollable: true,
  tabs: listTab

How to simplify a null-safe compareTo() implementation?

One of the simple way of using NullSafe Comparator is to use Spring implementation of it, below is one of the simple example to refer :

public int compare(Object o1, Object o2) {
        ValidationMessage m1 = (ValidationMessage) o1;
        ValidationMessage m2 = (ValidationMessage) o2;
        int c;
        if (m1.getTimestamp() == m2.getTimestamp()) {
            c =, m2.getProperty());
            if (c == 0) {
                c = m1.getSeverity().compareTo(m2.getSeverity());
                if (c == 0) {
                    c = m1.getMessage().compareTo(m2.getMessage());
        else {
            c = (m1.getTimestamp() > m2.getTimestamp()) ? -1 : 1;
        return c;

Can vue-router open a link in a new tab?

This works for me:

In HTML template: <a target="_blank" :href="url" @click.stop>your_name</a>

In mounted(): this.url = `${window.location.origin}/your_page_name`;

Python add item to the tuple

Tuple can only allow adding tuple to it. The best way to do it is:

mytuple =(u'2',)
mytuple +=(,)

I tried the same scenario with the below data it all seems to be working fine.

>>> mytuple = (u'2',)
>>> mytuple += ('example text',)
>>> print mytuple
(u'2','example text')

"This SqlTransaction has completed; it is no longer usable."... configuration error?

Had the exact same problem and just could not find the right solution. Hope this helps somebody.

I have an .NET Core 3.1 WebApi with EF Core. Upon receiving multiple calls at the same time, the applications was trying to add and save changes to the database at the same time.

In my case the problem was that the table that the data would be saved in did not have a primary key set.

Somehow EF Core missed when the migration was ran from the application that the ID in the model was supposed to be a primary key.

I found the problem by opening the SQL Profiler and seeing that all transactions was successfully submitted to the database (from the application) but only one new row was created. The profiler also showed that some type of deadlock was happening but I couldn't see much more in the trace logs of the profiler. On further inspection I noticed that the primary key identifier was missing on the column "Id".

The exceptions I got from my application was:

This SqlTransaction has completed; it is no longer usable.


An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure()' to the 'UseSqlServer' call.

How to support different screen size in android

You can figure out the dimensions of the screen dynamically

Display mDisplay= activity.getWindowManager().getDefaultDisplay();
int width= mDisplay.getWidth();
int Height= mDisplay.getHeight();

The layout can be set using the width and the height obtained using this method.

Add a "sort" to a =QUERY statement in Google Spreadsheets

Sorting by C and D needs to be put into number form for the corresponding column, ie 3 and 4, respectively. Eg Order By 2 asc")

Can't bind to 'formGroup' since it isn't a known property of 'form'

if this is just a typescript error but everything on your form works,you may just have to restart your IDE

Exporting the values in List to excel

I know, I am late to this party, however I think it could be helpful for others.

Already posted answers are for csv and other one is by Interop dll where you need to install excel over the server, every approach has its own pros and cons. Here is an option which will give you

  1. Perfect excel output [not csv]
  2. With perfect excel and your data type match
  3. Without excel installation
  4. Pass list and get Excel output :)

you can achieve this by using NPOI DLL, available for both .net as well as for .net core

Steps :

  1. Import NPOI DLL
  2. Add Section 1 and 2 code provided below
  3. Good to go

Section 1

This code performs below task :

  1. Creating New Excel object - _workbook = new XSSFWorkbook();
  2. Creating New Excel Sheet object - _sheet =_workbook.CreateSheet(_sheetName);
  3. Invokes WriteData() - explained later Finally, creating and
  4. returning MemoryStream object


using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;

namespace GenericExcelExport.ExcelExport
    public interface IAbstractDataExport
        HttpResponseMessage Export(List exportData, string fileName, string sheetName);

    public abstract class AbstractDataExport : IAbstractDataExport
        protected string _sheetName;
        protected string _fileName;
        protected List _headers;
        protected List _type;
        protected IWorkbook _workbook;
        protected ISheet _sheet;
        private const string DefaultSheetName = "Sheet1";

        public HttpResponseMessage Export
              (List exportData, string fileName, string sheetName = DefaultSheetName)
            _fileName = fileName;
            _sheetName = sheetName;

            _workbook = new XSSFWorkbook(); //Creating New Excel object
            _sheet = _workbook.CreateSheet(_sheetName); //Creating New Excel Sheet object

            var headerStyle = _workbook.CreateCellStyle(); //Formatting
            var headerFont = _workbook.CreateFont();
            headerFont.IsBold = true;

            WriteData(exportData); //your list object to NPOI excel conversion happens here

            var header = _sheet.CreateRow(0);
            for (var i = 0; i < _headers.Count; i++)
                var cell = header.CreateCell(i);
                cell.CellStyle = headerStyle;

            for (var i = 0; i < _headers.Count; i++)

            using (var memoryStream = new MemoryStream()) //creating memoryStream
                var response = new HttpResponseMessage(HttpStatusCode.OK)
                    Content = new ByteArrayContent(memoryStream.ToArray())

                response.Content.Headers.ContentType = new MediaTypeHeaderValue
                response.Content.Headers.ContentDisposition = 
                       new ContentDispositionHeaderValue("attachment")
                    FileName = $"{_fileName}_{DateTime.Now.ToString("yyyyMMddHHmmss")}.xlsx"

                return response;

        //Generic Definition to handle all types of List
        public abstract void WriteData(List exportData);


Section 2

In section 2, we will be performing below steps :

  1. Converts List to DataTable Reflection to read property name, your
  2. Column header will be coming from here
  3. Loop through DataTable to Create excel Rows


using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Text.RegularExpressions;

namespace GenericExcelExport.ExcelExport
    public class AbstractDataExportBridge : AbstractDataExport
        public AbstractDataExportBridge()
            _headers = new List<string>();
            _type = new List<string>();

        public override void WriteData<T>(List<T> exportData)
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));

            DataTable table = new DataTable();

            foreach (PropertyDescriptor prop in properties)
                var type = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
                table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? 
                string name = Regex.Replace(prop.Name, "([A-Z])", " $1").Trim(); //space separated 
                                                                           //name by caps for header

            foreach (T item in exportData)
                DataRow row = table.NewRow();
                foreach (PropertyDescriptor prop in properties)
                    row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;

            IRow sheetRow = null;

            for (int i = 0; i < table.Rows.Count; i++)
                sheetRow = _sheet.CreateRow(i + 1);
                for (int j = 0; j < table.Columns.Count; j++)
                    ICell Row1 = sheetRow.CreateCell(j);

                    string type = _type[j].ToLower();
                    var currentCellValue = table.Rows[i][j];

                    if (currentCellValue != null && 
                        if (type == "string")
                        else if (type == "int32")
                        else if (type == "double")


Now you just need to call WriteData() function by passing your list, and it will provide you your excel.

I have tested it in WEB API and WEB API Core, works like a charm.

Revert a jQuery draggable object back to its original container on out event of droppable

If you want to revert the element to the source position if it's not dropped inside a #droppable element, just save the original parent element of the draggable at the start of the script (instead of the position), and if you verify that it's not dropped into #droppable, then just restore the parent of #draggable to this original element.

So, replace this:

}).each(function() {
    var top = $(this).position().top;
    var left = $(this).position().left;
    $(this).data('orgTop', top);
    $(this).data('orgLeft', left);

with this:

}).each(function() {
    $(this).data('originalParent', $(this).parent())

Here, you'll have the original parent element of the draggable. Now, you have to restore it's parent in a precise moment.

drop is called every time the element is dragged out from the droppable, not at the stop. So, you're adding a lot of event callbacks. This is wrong, because you never clean the mouseup event. A good place where you can hook a callback and check if the element was dropped inside or outside the #droppable element, is revert, and you're doing it right now, so, just delete the drop callback.

When the element is dropped, and needs to know if it should be reverted or not, you know for sure that you'll not have any other interaction from the user until the new drag start. So, using the same condition you're using to know if it should revert or know, let's replace this alert with a fragment of code that: restores the parent element to the original div, and resets the originalPosition from the draggable internals. The originalPosition proeprty is setted at the time of _mouseStart, so, if you change the owner of the element, you should reset it, in order to make the animation of revert go to the proper place. So, let's set this to {top: 0, left: 0}, making the animation go to the origin point of the element:

revert: function(dropped) {
    var dropped = dropped && dropped[0].id == "droppable";
    if(!dropped) {
        $(this).data("draggable").originalPosition = {top:0, left:0}
    return !dropped;

And that's it! You can check this working here:

Take into consideration that, if in any jQuery's UI update, the behavior of revert or originalPosition changes, you'll need to update your code in order to make it work. Keep in mind that.

If you need a solution which doesn't make use of calls to the internals of ui.draggable, you can make your body an droppable element with greedy option defined as false. You'll have to make sure that your body elements take the full screen.

Good luck!

php artisan migrate throwing [PDO Exception] Could not find driver - Using Laravel

Assuming you did the normal installation with virtual box, vagrant etc.. This can happen to new people. PHP can be installed on your PC but all the modules PHP for your laravel project is on your VM So to access your VM, go to your homestead folder and type: vagrant ssh

then to go your project path and execute the php artisan migrate.

How to run multiple SQL commands in a single SQL connection?

using (var connection = new SqlConnection("Enter Your Connection String"))
        using (var command = connection.CreateCommand())
            command.CommandText = "Enter the First Command Here";
            command.CommandText = "Enter Second Comand Here";

    //Similarly You can Add Multiple

In C#, should I use string.Empty or String.Empty or "" to intitialize a string?

I strongly prefer String.Empty, aside from the other reasons to ensure you know what it is and that you have not accidentally removed the contents, but primarily for internationalization. If I see a string in quotes then I always have to wonder whether that is new code and it should be put into a string table. So every time code gets changed/reviewed you need to look for "something in quotes" and yes you can filter out the empty strings but I tell people it is good practice to never put strings in quotes unless you know it won't get localized.

Jquery function return value

The return statement you have is stuck in the inner function, so it won't return from the outer function. You just need a little more code:

function getMachine(color, qty) {
    var returnValue = null;
    $("#getMachine li").each(function() {
        var thisArray = $(this).text().split("~");
        if(thisArray[0] == color&& qty>= parseInt(thisArray[1]) && qty<= parseInt(thisArray[2])) {
            returnValue = thisArray[3];
            return false; // this breaks out of the each
    return returnValue;

var retval = getMachine(color, qty);

Passing parameter to controller action from a Html.ActionLink

Addition to the accepted answer:

if you are going to use

 @Html.ActionLink("LinkName", "ActionName", "ControllerName", new { @id = idValue, @secondParam= = 2 },null)

this will create actionlink where you can't create new custom attribute or style for the link.

However, the 4th parameter in ActionLink extension will solve that problem. Use the 4th parameter for customization in your way.

 @Html.ActionLink("LinkName", "ActionName", "ControllerName", new { @id = idValue, @secondParam= = 2 }, new { @class = "btn btn-info", @target = "_blank" })

Using LIMIT within GROUP BY to get N results per group?

The following post: sql: selcting top N record per group describes the complicated way of achieving this without subqueries.

It improves on other solutions offered here by:

  • Doing everything in a single query
  • Being able to properly utilize indexes
  • Avoiding subqueries, notoriously known to produce bad execution plans in MySQL

It is however not pretty. A good solution would be achievable were Window Functions (aka Analytic Functions) enabled in MySQL -- but they are not. The trick used in said post utilizes GROUP_CONCAT, which is sometimes described as "poor man's Window Functions for MySQL".

Java Multiple Inheritance

I think it depends very much on your needs, and how your animal classes are to be used in your code.

If you want to be able to make use of methods and features of your Horse and Bird implementations inside your Pegasus class, then you could implement Pegasus as a composition of a Bird and a Horse:

public class Animals {

    public interface Animal{
        public int getNumberOfLegs();
        public boolean canFly();
        public boolean canBeRidden();

    public interface Bird extends Animal{
        public void doSomeBirdThing();
    public interface Horse extends Animal{
        public void doSomeHorseThing();
    public interface Pegasus extends Bird,Horse{


    public abstract class AnimalImpl implements Animal{
        private final int numberOfLegs;

        public AnimalImpl(int numberOfLegs) {
            this.numberOfLegs = numberOfLegs;

        public int getNumberOfLegs() {
            return numberOfLegs;

    public class BirdImpl extends AnimalImpl implements Bird{

        public BirdImpl() {

        public boolean canFly() {
            return true;

        public boolean canBeRidden() {
            return false;

        public void doSomeBirdThing() {
            System.out.println("doing some bird thing...");


    public class HorseImpl extends AnimalImpl implements Horse{

        public HorseImpl() {

        public boolean canFly() {
            return false;

        public boolean canBeRidden() {
            return true;

        public void doSomeHorseThing() {
            System.out.println("doing some horse thing...");


    public class PegasusImpl implements Pegasus{

        private final Horse horse = new HorseImpl();
        private final Bird bird = new BirdImpl();

        public void doSomeBirdThing() {

        public int getNumberOfLegs() {
            return horse.getNumberOfLegs();

        public void doSomeHorseThing() {

        public boolean canFly() {
            return true;

        public boolean canBeRidden() {
            return true;

Another possibility is to use an Entity-Component-System approach instead of inheritance for defining your animals. Of course this means, that you will not have individual Java classes of the animals, but instead they are only defined by their components.

Some pseudo code for an Entity-Component-System approach could look like this:

public void createHorse(Entity entity){
    entity.setComponent(NUMER_OF_LEGS, 4);
    entity.setComponent(CAN_FLY, false);
    entity.setComponent(CAN_BE_RIDDEN, true);
    entity.setComponent(SOME_HORSE_FUNCTIONALITY, new HorseFunction());

public void createBird(Entity entity){
    entity.setComponent(NUMER_OF_LEGS, 2);
    entity.setComponent(CAN_FLY, true);
    entity.setComponent(CAN_BE_RIDDEN, false);
    entity.setComponent(SOME_BIRD_FUNCTIONALITY, new BirdFunction());

public void createPegasus(Entity entity){
    entity.setComponent(CAN_BE_RIDDEN, true);

Why does Date.parse give incorrect results?

This light weight date parsing library should solve all similar problems. I like the library because it is quite easy to extend. It's also possible to i18n it (not very straight forward, but not that hard).

Parsing example:

var caseOne = Date.parseDate("Jul 8, 2005", "M d, Y");
var caseTwo = Date.parseDate("2005-07-08", "Y-m-d");

And formatting back to string (you will notice both cases give exactly the same result):

console.log( caseOne.dateFormat("M d, Y") );
console.log( caseTwo.dateFormat("M d, Y") );
console.log( caseOne.dateFormat("Y-m-d") );
console.log( caseTwo.dateFormat("Y-m-d") );

How do I set the figure title and axes labels font size in Matplotlib?

You can also do this globally via a rcParams dictionary:

import matplotlib.pylab as pylab
params = {'legend.fontsize': 'x-large',
          'figure.figsize': (15, 5),
         'axes.labelsize': 'x-large',

What are the differences between if, else, and else if?

What the if says:

Whether I'm true or not, always check other conditions too.

What the else if says:

Only check other conditions if i wasn't true.

Visual Studio 2017 does not have Business Intelligence Integration Services/Projects

Integration Services project templates are now available in the latest release of SSDT for Visual Studio 2017.

Note: if you have recently installed SSDT for Visual Studio 2017. You need to remove the Reporting Services and Analysis Services installations before you proceed with installing SSDT.

Detect Close windows event by jQuery

Combine the mousemove and window.onbeforeunload event :- I used for set TimeOut for Audit Table.

 $(document).ready(function () {
 var checkCloseX = 0;
        $(document).mousemove(function (e) {
            if (e.pageY <= 5) {
                checkCloseX = 1;
            else { checkCloseX = 0; }

        window.onbeforeunload = function (event) {
            if (event) {
                if (checkCloseX == 1) {

                        type: "GET",
                        url: "Account/SetAuditHeaderTimeOut",
                        dataType: "json",
                        success: function (result) {
                            if (result != null) {

ASP.NET document.getElementById('<%=Control.ClientID%>'); returns null


You have to use RegisterStartupScript instead of RegisterClientScriptBlock

Here My Example.


<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="MasterPage.master.cs"
    Inherits="prueba.MasterPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "">
<html xmlns="">
<head runat="server">

    <script type="text/javascript">

        function confirmCallBack() {
            var a = document.getElementById('<%= Page.Master.FindControl("ContentPlaceHolder1").FindControl("Button1").ClientID %>');




    <asp:ContentPlaceHolder ID="head" runat="server">
    <form id="form1" runat="server">
        <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">


<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.Master" AutoEventWireup="true"
    CodeBehind="WebForm1.aspx.cs" Inherits="prueba.WebForm1" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">


<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" />


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace prueba
    public partial class WebForm1 : System.Web.UI.Page
        protected void Page_Load(object sender, EventArgs e)
            ClientScript.RegisterStartupScript(this.GetType(), "js", "confirmCallBack();", true);


What is the Java equivalent for LINQ?

There was the programming language Pizza (a Java extension) and you should have a look to it. - It uses the concept of "fluent interfaces" to query data in a declarative manner and that is in principle identical to LINQ w/o query expressions ( But alas it was not pursued, but it would have been one way to get something similar to LINQ into Java.

Custom Date Format for Bootstrap-DatePicker

I'm sure you are using a old version. You must use the last version available at master branch:

Define preprocessor macro through CMake?

To do this for a specific target, you can do the following:

target_compile_definitions(my_target PRIVATE FOO=1 BAR=1)

You should do this if you have more than one target that you're building and you don't want them all to use the same flags. Also see the official documentation on target_compile_definitions.

T-SQL - function with default parameters

With user defined functions, you have to declare every parameter, even if they have a default value.

The following would execute successfully:

IF dbo.CheckIfSFExists( 23, default ) = 0
    SET @retValue = 'bla bla bla;

How to kill/stop a long SQL query immediately?

A simple answer, if the red "stop" box is not working, is to try pressing the "Ctrl + Break" buttons on the keyboard.

If you are running SQL Server on Linux, there is an app you can add to your systray called "killall" Just click on the "killall" button and then click on the program that is caught in a loop and it will terminate the program. Hope that helps.

How to get the day name from a selected date?

//default locale
//localized version

To make the answer more complete:

Find the number of downloads for a particular app in apple appstore

I think developers can do this for their own apps via iTunes Connect but this doesn't help you if you are looking for stats on other peoples apps.

148Apps also have some aggregate AppStore metrics on their web site that could be useful to you but, again, doesn't really give a low-level breakdown of numbers.

You could also scrape some stats from the RSS feeds generated by the iTunes Store RSS Generator but, again, this just gets currently popular apps rather than actual download numbers.

How to execute a shell script in PHP?

You might have disabled the exec privileges, most of the LAMP packages have those disabled. Check your php.ini for this line:

disable_functions = exec

And remove the exec, shell_exec entries if there are there.

Good Luck!

The most accurate way to check JS object's type?

Accepted answer is correct, but I like to define this little utility in most projects I build.

var types = {
   'get': function(prop) {
   'null': '[object Null]',
   'object': '[object Object]',
   'array': '[object Array]',
   'string': '[object String]',
   'boolean': '[object Boolean]',
   'number': '[object Number]',
   'date': '[object Date]',

Used like this:

if(types.get(prop) == types.number) {


If you're using angular you can even have it cleanly injected:

angular.constant('types', types);

Bootstrap row class contains margin-left and margin-right which creates problems

I used div class="form-control" instead of div class="row"

That fixed for me.

How do you upload a file to a document library in sharepoint?

You can upload documents to SharePoint libraries using the Object Model or SharePoint Webservices.

Upload using Object Model:

String fileToUpload = @"C:\YourFile.txt";
String sharePointSite = "";
String documentLibraryName = "Shared Documents";

using (SPSite oSite = new SPSite(sharePointSite))
    using (SPWeb oWeb = oSite.OpenWeb())
        if (!System.IO.File.Exists(fileToUpload))
            throw new FileNotFoundException("File not found.", fileToUpload);                    

        SPFolder myLibrary = oWeb.Folders[documentLibraryName];

        // Prepare to upload
        Boolean replaceExistingFiles = true;
        String fileName = System.IO.Path.GetFileName(fileToUpload);
        FileStream fileStream = File.OpenRead(fileToUpload);

        // Upload document
        SPFile spfile = myLibrary.Files.Add(fileName, fileStream, replaceExistingFiles);

        // Commit 

Matplotlib subplots_adjust hspace so titles and xlabels don't overlap?

The link posted by Jose has been updated and pylab now has a tight_layout() function that does this automatically (in matplotlib version 1.1.0).

SQL Server convert string to datetime

For instance you can use

update tablename set datetimefield='19980223 14:23:05'
update tablename set datetimefield='02/23/1998 14:23:05'
update tablename set datetimefield='1998-12-23 14:23:05'
update tablename set datetimefield='23 February 1998 14:23:05'
update tablename set datetimefield='1998-02-23T14:23:05'

You need to be careful of day/month order since this will be language dependent when the year is not specified first. If you specify the year first then there is no problem; date order will always be year-month-day.

How to enable Google Play App Signing

This guide is oriented to developers who already have an application in the Play Store. If you are starting with a new app the process it's much easier and you can follow the guidelines of paragraph "New apps" from here

Prerequisites that 99% of developers already have :

  1. Android Studio

  2. JDK 8 and after installation you need to setup an environment variable in your user space to simplify terminal commands. In Windows x64 you need to add this : C:\Program Files\Java\{JDK_VERSION}\bin to the Path environment variable. (If you don't know how to do this you can read my guide to add a folder to the Windows 10 Path environment variable).

Step 0: Open Google Play developer console, then go to Release Management -> App Signing.

enter image description here

Accept the App Signing TOS.

enter image description here

Step 1: Download PEPK Tool clicking the button identical to the image below

enter image description here

Step 2: Open a terminal and type:



  • PATH_TO_PEPK = Path to the pepk.jar you downloaded in Step 1, could be something like C:\Users\YourName\Downloads\pepk.jar for Windows users.
  • PATH_TO_KEYSTORE = Path to keystore which you use to sign your release APK. Could be a file of type *.keystore or *.jks or without extension. Something like C:\Android\mykeystore or C:\Android\mykeystore.keystore etc...
  • ALIAS_YOU_USE_TO_SIGN_APK = The name of the alias you use to sign the release APK.
  • PATH_TO_OUTPUT_FILE = The path of the output file with .pem extension, something like C:\Android\private_key.pem
  • GOOGLE_ENCRYPTION_KEY = This encryption key should be always the same. You can find it in the App Signing page, copy and paste it. Should be in this form: eb10fe8f7c7c9df715022017b00c6471f8ba8170b13049a11e6c09ffe3056a104a3bbe4ac5a955f4ba4fe93fc8cef27558a3eb9d2a529a2092761fb833b656cd48b9de6a


java -jar "C:\Users\YourName\Downloads\pepk.jar" --keystore="C:\Android\mykeystore" --alias=myalias --output="C:\Android\private_key.pem" --encryptionkey=eb10fe8f7c7c9df715022017b00c6471f8ba8170b13049a11e6c09ffe3056a104a3bbe4ac5a955f4ba4fe93fc8cef27558a3eb9d2a529a2092761fb833b656cd48b9de6a

Press Enter and you will need to provide in order:

  1. The keystore password
  2. The alias password

If everything has gone OK, you now will have a file in PATH_TO_OUTPUT_FILE folder called private_key.pem.

Step 3: Upload the private_key.pem file clicking the button identical to the image below

enter image description here

Step 4: Create a new keystore file using Android Studio.


Open one of your Android projects (choose one at random). Go to Build -> Generate Signed APK and press Create new.

enter image description here

Now you should fill the required fields.

Key store path represent the new keystore you will create, choose a folder and a name using the 3 dots icon on the right, i choosed C:\Android\upload_key.jks (.jks extension will be added automatically)

NOTE: I used upload as the new alias name but if you previously used the same keystore with different aliases to sign different apps, you should choose the same aliases name you had previously in the original keystore.

enter image description here

Press OK when finished, and now you will have a new upload_key.jks keystore. You can close Android Studio now.

Step 5: We need to extract the upload certificate from the newly created upload_key.jks keystore. Open a terminal and type:

keytool -export -rfc -keystore UPLOAD_KEYSTORE_PATH -alias UPLOAD_KEYSTORE_ALIAS -file PATH_TO_OUTPUT_FILE


  • UPLOAD_KEYSTORE_PATH = The path of the upload keystore you just created. In this case was C:\Android\upload_key.jks.
  • UPLOAD_KEYSTORE_ALIAS = The new alias associated with the upload keystore. In this case was upload.
  • PATH_TO_OUTPUT_FILE = The path to the output file with .pem extension. Something like C:\Android\upload_key_public_certificate.pem.


keytool -export -rfc -keystore "C:\Android\upload_key.jks" -alias upload -file "C:\Android\upload_key_public_certificate.pem"

Press Enter and you will need to provide the keystore password.

Now if everything has gone OK, you will have a file in the folder PATH_TO_OUTPUT_FILE called upload_key_public_certificate.pem.

Step 6: Upload the upload_key_public_certificate.pem file clicking the button identical to the image below

enter image description here

Step 7: Click ENROLL button at the end of the App Signing page.

enter image description here

Now every new release APK must be signed with the upload_key.jks keystore and aliases created in Step 4, prior to be uploaded in the Google Play Developer console.

More Resources:


Q: When i upload the APK signed with the new upload_key keystore, Google Play show an error like : You uploaded an unsigned APK. You need to create a signed APK.

A: Check to sign the APK with both signatures (V1 and V2) while building the release APK. Read here for more details.


The step 4,5,6 are to create upload key which is optional for existing apps

"Upload key (optional for existing apps): A new key you generate during your enrollment in the program. You will use the upload key to sign all future APKs prior to uploading them to the Play Console."

How to encrypt and decrypt file in Android?

You could use java-aes-crypto or Facebook's Conceal


Quoting from the repo

A simple Android class for encrypting & decrypting strings, aiming to avoid the classic mistakes that most such classes suffer from.

Facebook's conceal

Quoting from the repo

Conceal provides easy Android APIs for performing fast encryption and authentication of data

python pip - install from local dir

You were looking for help on installations with pip. You can find it with the following command:

pip install --help

Running pip install -e /path/to/package installs the package in a way, that you can edit the package, and when a new import call looks for it, it will import the edited package code. This can be very useful for package development.

How to restart a single container with docker-compose

The answer's here are talking about the reflection of the change on the docker-compose.yml file.

But what if I want to incorporate the changes I have done in my code, and I believe that will be only possible by rebuilding the image and that I do with following commands

1. docker container stop

docker stop container-id

2. docker container removal

docker rm container-id

3. docker image removal

docker rmi image-id

4. compose the container again

docker-compose up container-name

counting the number of lines in a text file

with for-loop:

std::ifstream myFile;
std::string line;
int lines;;

for(lines = 0; std::getline(myFile,line); lines++);

std::cout << lines << std::endl;

How to increment a variable on a for loop in jinja template?

As Jeroen says there are scoping issues: if you set 'count' outside the loop, you can't modify it inside the loop.

You can defeat this behavior by using an object rather than a scalar for 'count':

{% set count = [1] %}

You can now manipulate count inside a forloop or even an %include%. Here's how I increment count (yes, it's kludgy but oh well):

{% if count.append(count.pop() + 1) %}{% endif %} {# increment count by 1 #}

Android : Capturing HTTP Requests with non-rooted android device

You could install Charles - an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet - on your PC or MAC.

Config steps:

  • Let your phone and PC or MAC in a same LAN
  • Launch Charles which you installed (default proxy port is 8888)
  • Setup your phone's wifi configuration: set the ip of delegate to your PC or MAC's ip, port of delegate to 8888
  • Lauch your app in your phone. And monitor http requests on Charles.

How do I install imagemagick with homebrew?

Answering old thread here (and a bit off-topic) because it's what I found when I was searching how to install Image Magick on Mac OS to run on the local webserver. It's not enough to brew install Imagemagick. You have to also PECL install it so the PHP module is loaded.

From this SO answer:

brew install php
brew install imagemagick
brew install pkg-config
pecl install imagick

And you may need to sudo apachectl restart. Then check your phpinfo() within a simple php script running on your web server.

If it's still not there, you probably have an issue with running multiple versions of PHP on the same Mac (one through the command line, one through your web server). It's beyond the scope of this answer to resolve that issue, but there are some good options out there.

How can I restart a Java application?

Similar to Yoda's 'improved' answer, but with further improvements (both functional, readability, and testability). It's now safe to run, and restarts for as as many times as the amount of program arguments given.

  • No accumulation of JAVA_TOOL_OPTIONS options.
  • Automatically finds main class.
  • Inherits current stdout/stderr.

public static void main(String[] args) throws Exception {
    if (args.length == 0)
        args = Arrays.copyOf(args, args.length - 1);

    List<String> command = new ArrayList<>(32);
    appendArgs(command, args);

    try {
        new ProcessBuilder(command).inheritIO().start();
    } catch (IOException ex) {

private static void appendJavaExecutable(List<String> cmd) {
    cmd.add(System.getProperty("java.home") + File.separator + "bin" + File.separator + "java");

private static void appendVMArgs(Collection<String> cmd) {
    Collection<String> vmArguments = ManagementFactory.getRuntimeMXBean().getInputArguments();

    String javaToolOptions = System.getenv("JAVA_TOOL_OPTIONS");
    if (javaToolOptions != null) {
        Collection<String> javaToolOptionsList = Arrays.asList(javaToolOptions.split(" "));
        vmArguments = new ArrayList<>(vmArguments);


private static void appendClassPath(List<String> cmd) {

    private static void appendEntryPoint(List<String> cmd) {
    StackTraceElement[] stackTrace          = new Throwable().getStackTrace();
    StackTraceElement   stackTraceElement   = stackTrace[stackTrace.length - 1];
    String              fullyQualifiedClass = stackTraceElement.getClassName();
    String              entryMethod         = stackTraceElement.getMethodName();
    if (!entryMethod.equals("main"))
        throw new AssertionError("Entry point is not a 'main()': " + fullyQualifiedClass + '.' + entryMethod);


private static void appendArgs(List<String> cmd, String[] args) {

V1.1 Bugfix: null pointer if JAVA_TOOL_OPTIONS is not set


$ java -cp Temp.jar Temp a b c d e
[/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java, -cp, Temp.jar, Temp, a, b, c, d]
[/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java, -cp, Temp.jar, Temp, a, b, c]
[/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java, -cp, Temp.jar, Temp, a, b]
[/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java, -cp, Temp.jar, Temp, a]
[/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java, -cp, Temp.jar, Temp]

How to read a list of files from a folder using PHP?

This is what I like to do:

$files = array_values(array_filter(scandir($path), function($file) use ($path) { 
    return !is_dir($path . '/' . $file);

foreach($files as $file){
    echo $file;

Difference between text and varchar (character varying)

text and varchar have different implicit type conversions. The biggest impact that I've noticed is handling of trailing spaces. For example ...

select ' '::char = ' '::varchar, ' '::char = ' '::text, ' '::varchar = ' '::text

returns true, false, true and not true, true, true as you might expect.

Adjust plot title (main) position

Try this:

par(adj = 0)
plot(1, 1, main = "Title")

or equivalent:

plot(1, 1, main = "Title", adj = 0)

adj = 0 produces left-justified text, 0.5 (the default) centered text and 1 right-justified text. Any value in [0, 1] is allowed.

However, the issue is that this will also change the position of the label of the x-axis and y-axis.

Mocking Extension Methods with Moq

So if you are using Moq, and want to mock the result of an Extension method, then you can use SetupReturnsDefault<ReturnTypeOfExtensionMethod>(new ConcreteInstanceToReturn()) on the instance of the mock class that has the extension method you are trying to mock.

It is not perfect, but for unit testing purposes it works well.

How can I change the remote/target repository URL on Windows?

One more way to do this is:

git config remote.origin.url

To see the existing URL just do:

git config remote.origin.url

VBA: How to delete filtered rows in Excel?

As an alternative to using UsedRange or providing an explicit range address, the AutoFilter.Range property can also specify the affected range.


As used here, Offset causes the first row after the AutoFilter range to also be deleted. In order to avoid that, I would try using .Resize() after .Offset().

How can I format decimal property to currency?

Below would also work, but you cannot put in the getter of a decimal property. The getter of a decimal property can only return a decimal, for which formatting does not apply.

decimal moneyvalue = 1921.39m; 
string currencyValue = moneyvalue.ToString("C");

How to check if a registry value exists using C#?

string keyName=@"HKEY_LOCAL_MACHINE\System\CurrentControlSet\services\pcmcia";
string valueName="Start";
if (Registry.GetValue(keyName, valueName, null) == null)
     //code if key Not Exist
     //code if key Exist

Razor/CSHTML - Any Benefit over what we have?

Ex Microsoft Developer's Opinion

I worked on a core team for the MSDN website. Now, I use c# razor for ecommerce sites with my programming team and we focus heavy on jQuery front end with back end c# razor pages and LINQ-Entity memory database so the pages are 1-2 millisecond response times even on nested for loops with queries and no page caching. We don't use MVC, just plain ASP.NET with razor pages being mapped with URL Rewrite module for IIS 7, no ASPX pages or ViewState or server-side event programming at all. It doesn't have the extra (unnecessary) layers MVC puts in code constructs for the regex challenged. Less is more for us. Its all lean and mean but I give props to MVC for its testability but that's all.

Razor pages have no event life cycle like ASPX pages. Its just rendering as one requested page. C# is such a great language and Razor gets out of its way nicely to let it do its job. The anonymous typing with generics and linq make life so easy with c# and razor pages. Using Razor pages will help you think and code lighter.

One of the drawback of Razor and MVC is there is no ViewState-like persistence. I needed to implement a solution for that so I ended up writing a jQuery plugin for that here -> which is an HTML 5 offline storage supported plugin for form state that is working in all major browsers now. It is just for form state currently but you can use window.sessionStorage or window.localStorage very simply to store any kind of state across postbacks or even page requests, I just bothered to make it autosave and namespace it based on URL and form index so you don't have to think about it.

Querying Datatable with where condition

You can do it with Linq, as mamoo showed, but the oldies are good too:

var filteredDataTable = dt.Select(@"EmpId > 2
    AND (EmpName <> 'abc' OR EmpName <> 'xyz')
    AND EmpName like '%il%'" );

How do I manually create a file with a . (dot) prefix in Windows? For example, .htaccess

Even if you don't have any third party editor (Notepad++ etc.) then also you can create files with dot as prefix.

To create .htaccess file, first create htaccess.txt file with Context Menu > New Text Document.

Then press Alt + D (Windows 7) and Ctrl + C to copy the path from the Address bar of Windows Explorer.

Then go to command line and type code as below to rename your file:

rename C:\path\to\htaccess.txt .htaccess

Now you have a blank .htaccess without opening it in any editor.

Hope this helps you out.

Python - Join with newline

When you print it with this print 'I\nwould\nexpect\nmultiple\nlines' you would get:


The \n is a new line character specially used for marking END-OF-TEXT. It signifies the end of the line or text. This characteristics is shared by many languages like C, C++ etc.

How to find path of active app.config file?

I tried one of the previous answers in a web app (actually an Azure web role running locally) and it didn't quite work. However, this similar approach did work:

var map = new ExeConfigurationFileMap { ExeConfigFilename = "MyComponent.dll.config" };
var path = ConfigurationManager.OpenMappedExeConfiguration(map, ConfigurationUserLevel.None).FilePath;

The config file turned out to be in C:\Program Files\IIS Express\MyComponent.dll.config. Interesting place for it.

MySQL show current connection info

There are MYSQL functions you can use. Like this one that resolves the user:


This will return something like root@localhost so you get the host and the user.

To get the current database run this statement:


Other useful functions can be found here:

select unique rows based on single distinct column

If you are using MySql 5.7 or later, according to these links (MySql Official, SO QA), we can select one record per group by with out the need of any aggregate functions.

So the query can be simplified to this.

select * from comments_table group by commentname;

Try out the query in action here

Calling Scalar-valued Functions in SQL

Can do the following

PRINT dbo.[FunctionName] ( [Parameter/Argument] )


PRINT dbo.StringSplit('77,54')

How to get diff between all files inside 2 folders that are on the web?

You urls are not in the same repository, so you can't do it with the svn diff command.

svn: '' isn't in the same repository as ''

Another way you could do it, is export each repos using svn export, and then use the diff command to compare the 2 directories you exported.

// Export repositories
svn export repos1
svn export repos2

// Compare exported directories
diff repos1 repos2 > file.diff

How can I run multiple npm scripts in parallel?

Quick Solution

In this case, I'd say the best bet If this script is for a private module intended to run only on *nix-based machines, you can use the control operator for forking processes, which looks like this: &

An example of doing this in a partial package.json file:

  "name": "npm-scripts-forking-example",
  "scripts": {
    "bundle": "watchify -vd -p browserify-hmr index.js -o bundle.js",
    "serve":  "http-server -c 1 -a localhost",
    "serve-bundle": "npm run bundle & npm run serve &"

You'd then execute them both in parallel via npm run serve-bundle. You can enhance the scripts to output the pids of the forked process to a file like so:

"serve-bundle": "npm run bundle & echo \"$!\" > build/ && npm run serve & echo \"$!\" > build/ && npm run open-browser",

Google something like bash control operator for forking to learn more on how it works. I've also provided some further context regarding leveraging Unix techniques in Node projects below:

Further Context RE: Unix Tools & Node.js

If you're not on Windows, Unix tools/techniques often work well to achieve something with Node scripts because:

  1. Much of Node.js lovingly imitates Unix principles
  2. You're on *nix (incl. OS X) and NPM is using a shell anyway

Modules for system tasks in Nodeland are also often abstractions or approximations of Unix tools, from fs to streams.

Initialise numpy array of unknown length

Since y is an iterable I really do not see why the calls to append:

a = np.array(list(y))

will do and it's much faster:

import timeit

print timeit.timeit('list(s)', 's=set(x for x in xrange(1000))')
# 23.952975494633154

print timeit.timeit("""li=[]
for x in s: li.append(x)""", 's=set(x for x in xrange(1000))')
# 189.3826994248866

jQuery: more than one handler for same event

You should be able to use chaining to execute the events in sequence, e.g.:

  .bind('click',function(event) {
  .bind('click',function(event) {
    alert('Hello again!');
  .bind('click',function(event) {
    alert('Hello yet again!');

I guess the below code is doing the same

      .click(function(event) {
      .click(function(event) {
        alert('Hello again!');
      .click(function(event) {
        alert('Hello yet again!');


TFM also says:

When an event reaches an element, all handlers bound to that event type for the element are fired. If there are multiple handlers registered, they will always execute in the order in which they were bound. After all handlers have executed, the event continues along the normal event propagation path.

Error in spring application context schema

What I did with spring-data-jpa-1.3 was adding a version to xsd and lowered it to 1.2. Then the error message disappears. Like this


Seems like it was fixed for for 1.2 but then appears again in 1.3.

How to retrieve images from MySQL database and display in an html tag

Technically, you can too put image data in an img tag, using data URIs.

<img src="data:image/jpeg;base64,<?php echo base64_encode( $image_data ); ?>" />

There are some special circumstances where this could even be useful, although in most cases you're better off serving the image through a separate script like daiscog suggests.

Laravel migration: unique key is too long, even if specified

Change charset to from 'utf8mb4' to 'utf8' and

collation to 'utf8mb4_unicode_ci' to 'utf8_unicode_ci'

in config/database.php file

It worked for me.

git replacing LF with CRLF

  1. Open the file in the Notepad++.
  2. Go to Edit/EOL Conversion.
  3. Click to the Windows Format.
  4. Save the file.

GIT fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree

Jacob Helwig mentions in his answer that:

It looks like rev-parse is being used without sufficient error checking before-hand

Commit 62f162f from Jeff King (peff) should improve the robustness of git rev-parse in Git 1.9/2.0 (Q1 2014) (in addition of commit 1418567):

For cases where we do not match (e.g., "doesnotexist..HEAD"), we would then want to try to treat the argument as a filename.
try_difference() gets this right, and always unmunges in this case.
However, try_parent_shorthand() never unmunges, leading to incorrect error messages, or even incorrect results:

$ git rev-parse foobar^@
fatal: ambiguous argument 'foobar': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

What is the intended use-case for git stash?

I will break answer on three paragraphs.

Part 1:

git stash (To save your un-committed changes in a "stash". Note: this removes changes from working tree!)

git checkout some_branch (change to intended branch -- in this case some_branch)

git stash list (list stashes)

You can see:
stash@{0}: WIP on {branch_name}: {SHA-1 of last commit} {last commit of you branch}
stash@{0}: WIP on master: 085b095c6 modification for test

git stash apply (to apply stash to working tree in current branch)

git stash apply stash@{12} (if you will have many stashes you can choose what stash will apply -- in this case we apply stash 12)

git stash drop stash@{0} (to remove from stash list -- in this case stash 0)

git stash pop stash@{1} (to apply selected stash and drop it from stash list)

Part 2:
You can hide your changes with this command but it is not necessary.
You can continue on the next day without stash.
This commands for hide your changes and work on different branches or for implementation some realisation of your code and save in stashes without branches and commitsor your custom case!
And later you can use some of stashes and check wich is better.

Part 3:
Stash command for local hide your changes.
If you want work remotely you must commit and push.

How to get text of an element in Selenium WebDriver, without including child element text?

In the HTML which you have shared:

<div id="a">This is some
   <div id="b">text</div>

The text This is some is within a text node. To depict the text node in a structured way:

<div id="a">
    This is some
   <div id="b">text</div>

This Usecase

To extract and print the text This is some from the text node using Selenium's client you have 2 ways as follows:

  • Using splitlines(): You can identify the parent element i.e. <div id="a">, extract the innerHTML and then use splitlines() as follows:

    • using xpath:

    • using xpath:

  • Using execute_script(): You can also use the execute_script() method which can synchronously execute JavaScript in the current window/frame as follows:

    • using xpath and firstChild:

      parent_element = driver.find_element_by_xpath("//div[@id='a']")
      print(driver.execute_script('return arguments[0].firstChild.textContent;', parent_element).strip())
    • using xpath and childNodes[n]:

      parent_element = driver.find_element_by_xpath("//div[@id='a']")
      print(driver.execute_script('return arguments[0].childNodes[1].textContent;', parent_element).strip())

SQL Server Configuration Manager not found

you need to identify sql version.

SQLServerManager15.msc for [SQL Server 2019] or

SQLServerManager14.msc for [SQL Server 2017] or

SQLServerManager13.msc for [SQL Server 2016] or

SQLServerManager12.msc for [SQL Server 2014] or

SQLServerManager11.msc for [SQL Server 2012] or

SQLServerManager10.msc for [SQL Server 2008],

enter image description here

Step :1) open ssms

  2) select version

  3) select above command and run in cmd with admin right.