Programs & Examples On #Dynamic variables

Using braces with dynamic variable names in PHP

I do this quite often on results returned from a query..

e.g.

// $MyQueryResult is an array of results from a query

foreach ($MyQueryResult as $key=>$value)
{
   ${$key}=$value;
}

Now I can just use $MyFieldname (which is easier in echo statements etc) rather than $MyQueryResult['MyFieldname']

Yep, it's probably lazy, but I've never had any problems.

Use dynamic variable names in JavaScript

I needed to draw multiple FormData on the fly and object way worked well

var forms = {}

Then in my loops whereever i needed to create a form data i used

forms["formdata"+counter]=new FormData();
forms["formdata"+counter].append(var_name, var_value);

Assigning variables with dynamic names in Java

You don't. The closest thing you can do is working with Maps to simulate it, or defining your own Objects to deal with.

Select default option value from typescript angular 6

First or all you are using ng-model which is considered to be an angularjs syntax. Use [(ngModel)] instead with the default value

App.component.html

<select [(ngModel)]='nrSelect' class='form-control'>
    <option value='47'>47</option>
    <option value='46'>46</option>
    <option value='45'>45</option>
</select>

App.component.ts

import { Component } from '@angular/core'; 
@Component({ 
    selector: 'my-app', 
    templateUrl: './app.component.html', 
    styleUrls: [ './app.component.css' ] 
}) 

export class AppComponent { 
    nrSelect:string = "47" 
}

Cannot assign requested address using ServerSocket.socketBind

In my case, delete from /etc/hosts

  • 127.0.0.1 localhost
  • 192.168.100.20 localhost <<<<---- (delete or comment)

How to rotate x-axis tick labels in Pandas barplot

The follows might be helpful:

# Valid font size are xx-small, x-small, small, medium, large, x-large, xx-large, larger, smaller, None

plt.xticks(
    rotation=45,
    horizontalalignment='right',
    fontweight='light',
    fontsize='medium',
)

Here is the function xticks[reference] with example and API

def xticks(ticks=None, labels=None, **kwargs):
    """
    Get or set the current tick locations and labels of the x-axis.

    Call signatures::

        locs, labels = xticks()            # Get locations and labels
        xticks(ticks, [labels], **kwargs)  # Set locations and labels

    Parameters
    ----------
    ticks : array_like
        A list of positions at which ticks should be placed. You can pass an
        empty list to disable xticks.

    labels : array_like, optional
        A list of explicit labels to place at the given *locs*.

    **kwargs
        :class:`.Text` properties can be used to control the appearance of
        the labels.

    Returns
    -------
    locs
        An array of label locations.
    labels
        A list of `.Text` objects.

    Notes
    -----
    Calling this function with no arguments (e.g. ``xticks()``) is the pyplot
    equivalent of calling `~.Axes.get_xticks` and `~.Axes.get_xticklabels` on
    the current axes.
    Calling this function with arguments is the pyplot equivalent of calling
    `~.Axes.set_xticks` and `~.Axes.set_xticklabels` on the current axes.

    Examples
    --------
    Get the current locations and labels:

        >>> locs, labels = xticks()

    Set label locations:

        >>> xticks(np.arange(0, 1, step=0.2))

    Set text labels:

        >>> xticks(np.arange(5), ('Tom', 'Dick', 'Harry', 'Sally', 'Sue'))

    Set text labels and properties:

        >>> xticks(np.arange(12), calendar.month_name[1:13], rotation=20)

    Disable xticks:

        >>> xticks([])
    """

Create a SQL query to retrieve most recent records

The derived table would work, but if this is SQL 2005, a CTE and ROW_NUMBER might be cleaner:

WITH UserStatus (User, Date, Status, Notes, Ord)
as
(
SELECT Date, User, Status, Notes, 
     ROW_NUMBER() OVER (PARTITION BY User ORDER BY Date DESC)
FROM [SOMETABLE]
)

SELECT User, Date, Status, Notes from UserStatus where Ord = 1

This would also facilitate the display of the most recent x statuses from each user.

How to convert minutes to hours/minutes and add various time values together using jQuery?

The function below will take as input # of minutes and output time in the following format: Hours:minutes. I used Math.trunc(), which is a new method added in 2015. It returns the integral part of a number by removing any fractional digits.

function display(a){
  var hours = Math.trunc(a/60);
  var minutes = a % 60;
  console.log(hours +":"+ minutes);
}

display(120); //"2:0"
display(60); //"1:0:
display(100); //"1:40"
display(126); //"2:6"
display(45); //"0:45"

Android - Best and safe way to stop thread

The thing is you need to check whether the thread is running or not !?

Field:

private boolean runningThread = false;

In the thread:

new Thread(new Runnable() {
            @Override
            public void run() {
                while (true) {
                    try {
                        Thread.sleep((long) Math.floor(speed));
                        if (!runningThread) {
                            return;
                        }
                        yourWork();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();

If you want to stop the thread you should make the below field

private boolean runningThread = false;

Using fonts with Rails asset pipeline

I had a similar issue when I upgraded my Rails 3 app to Rails 4 recently. My fonts were not working properly as in the Rails 4+, we are only allowed to keep the fonts under app/assets/fonts directory. But my Rails 3 app had a different font organization. So I had to configure the app so that it still works with Rails 4+ having my fonts in a different place other than app/assets/fonts. I have tried several solutions but after I found non-stupid-digest-assets gem, it just made it so easy.

Add this gem by adding the following line to your Gemfile:

gem 'non-stupid-digest-assets'

Then run:

bundle install

And finally add the following line in your config/initializers/non_digest_assets.rb file:

NonStupidDigestAssets.whitelist = [ /\.(?:svg|eot|woff|ttf)$/ ]

That's it. This solved my problem nicely. Hope this helps someone who have encountered similar problem like me.

What is the cleanest way to disable CSS transition effects temporarily?

If you want a simple no-jquery solution to prevent all transitions:

  1. Add this CSS:
body.no-transition * {
  transition: none !important;
}
  1. And then in your js:
document.body.classList.add("no-transition");

// do your work, and then either immediately remove the class:

document.body.classList.remove("no-transition");

// or, if browser rendering takes longer and you need to wait until a paint or two:

setTimeout(() => document.body.classList.remove("no-transition"), 1);

// (try changing 1 to a larger value if the transition is still applying)

How to get input field value using PHP

You can get the value $value as :

$value =  $_POST['subject'];

or:

$value = $_GET['subject']; ,depending upon the form method used.

session_start();
$_SESSION['subject'] =  $value;

the value is assigned to session variable subject.

This view is not constrained vertically. At runtime it will jump to the left unless you add a vertical constraint

Go to the Design, right click on your Widget, Constraint Layout >> Infer Constraints. You can observe that some code has been automatically added to your Text.

Getting rid of \n when using .readlines()

from string import rstrip

with open('bvc.txt') as f:
    alist = map(rstrip, f)

Nota Bene: rstrip() removes the whitespaces, that is to say : \f , \n , \r , \t , \v , \x and blank ,
but I suppose you're only interested to keep the significant characters in the lines. Then, mere map(strip, f) will fit better, removing the heading whitespaces too.


If you really want to eliminate only the NL \n and RF \r symbols, do:

with open('bvc.txt') as f:
    alist = f.read().splitlines()

splitlines() without argument passed doesn't keep the NL and RF symbols (Windows records the files with NLRF at the end of lines, at least on my machine) but keeps the other whitespaces, notably the blanks and tabs.

.

with open('bvc.txt') as f:
    alist = f.read().splitlines(True)

has the same effect as

with open('bvc.txt') as f:
    alist = f.readlines()

that is to say the NL and RF are kept

How to get current instance name from T-SQL

SELECT @@servername will give you data as server/instanceName

To get only the instanceName you should run select @@ServiceName query .

Chrome refuses to execute an AJAX script due to wrong MIME type

For the record and Google search users, If you are a .NET Core developer, you should set the content-types manually, because their default value is null or empty:

var provider = new FileExtensionContentTypeProvider();
app.UseStaticFiles(new StaticFileOptions
{
    ContentTypeProvider = provider
});

Python: For each list element apply a function across the list

>>> nums = [1, 2, 3, 4, 5]    
>>> min(map((lambda t: ((float(t[0])/t[1]), t)), ((x, y) for x in nums for y in nums)))[1]
(1, 5)

Converting string to title case

Alternative with reference to Microsoft.VisualBasic (handles uppercase strings too) :

string properCase = Strings.StrConv(str, VbStrConv.ProperCase);

How to convert/parse from String to char in java?

You can do the following:

String str = "abcd";
char arr[] = new char[len]; // len is the length of the array
arr = str.toCharArray();

Clear the entire history stack and start a new activity on Android

You shouldn't change the stack. Android back button should work as in a web browser.

I can think of a way to do it, but it's quite a hack.

  • Make your Activities singleTask by adding it to the AndroidManifest Example:

    <activity android:name=".activities.A"
              android:label="@string/A_title"
              android:launchMode="singleTask"/>
    
    <activity android:name=".activities.B"
              android:label="@string/B_title"
              android:launchMode="singleTask"/>
    
  • Extend Application which will hold the logic of where to go.

Example:

public class DontHackAndroidLikeThis extends Application {

  private Stack<Activity> classes = new Stack<Activity>();

  public Activity getBackActivity() {
    return classes.pop();
  }

  public void addBackActivity(Activity activity) {
    classes.push(activity);
  }
}

From A to B:

DontHackAndroidLikeThis app = (DontHackAndroidLikeThis) getApplication();
app.addBackActivity(A.class); 
startActivity(this, B.class);

From B to C:

DontHackAndroidLikeThis app = (DontHackAndroidLikeThis) getApplication();
app.addBackActivity(B.class); 
startActivity(this, C.class);

In C:

If ( shouldNotGoBackToB() ) {
  DontHackAndroidLikeThis app = (DontHackAndroidLikeThis) getApplication();
  app.pop();
}

and handle the back button to pop() from the stack.

Once again, you shouldn't do this :)

Changing EditText bottom line color with appcompat v7

I felt like this needed an answer in case somebody wanted to change just a single edittext. I do it like this:

editText.getBackground().mutate().setColorFilter(ContextCompat.getColor(context, R.color.your_color), PorterDuff.Mode.SRC_ATOP);

Provide an image for WhatsApp link sharing

In case someone is looking for a way to display preview using WhatsApp API, With including the image in your meta tags on your website you would need to set the preview_url=true.

Sending URLs in Text Messages

By default, the mobile WhatsApp application recognizes URLs and makes them clickable. To include a URL preview, include "preview_url": true in the message body and make sure the URL begins with http:// or https://. A hostname is required, IP addresses are not matched.

The majority of the time when you send a URL, whether with a preview or not, the receiver of the message will see a URL that they can click on.

URL previews will only be rendered after one of the following has happened:

  • The business has sent a message template to the user.
  • The userinitiates a conversation with a "click to chat" link.
  • The user adds the business phone number to their address book and initiates a conversation.

Read from a gzip file in python

python: read lines from compressed text files

Using gzip.GzipFile:

import gzip

with gzip.open('input.gz','r') as fin:        
    for line in fin:        
        print('got line', line)

Updating the value of data attribute using jQuery

I want to change the width and height of a div. data attributes did not change it. Instead I use:

var size = $("#theme_photo_size").val().split("x");
$("#imageupload_img").width(size[0]);
$("#imageupload_img").attr("data-width", size[0]);
$("#imageupload_img").height(size[1]);
$("#imageupload_img").attr("data-height", size[1]);

be careful:

$("#imageupload_img").data("height", size[1]); //did not work

did not set it

$("#imageupload_img").attr("data-height", size[1]); // yes it worked!

this has set it.

Cannot uninstall angular-cli

You have to use (without @)

npm uninstall -g angular/cli

because

If you're using Angular CLI beta.28 or less, you need to uninstall angular-cli package. It should be done due to changing of package's name and scope from angular-cli to @angular/cli https://github.com/angular/angular-cli

Upgrade python in a virtualenv

Updated again: The following method might not work in newer versions of virtualenv. Before you try to make modifications to the old virtualenv, you should save the dependencies in a requirement file (pip freeze > requirements.txt) and make a backup of it somewhere else. If anything goes wrong, you can still create a new virtualenv and install the old dependencies in it (pip install -r requirements.txt).

Updated: I changed the answer 5 months after I originally answered. The following method is more convenient and robust.

Side effect: it also fixes the Symbol not found: _SSLv2_method exception when you do import ssl in a virtual environment after upgrading Python to v2.7.8.

Notice: Currently, this is for Python 2.7.x only.


If you're using Homebrew Python on OS X, first deactivate all virtualenv, then upgrade Python:

brew update && brew upgrade python

Run the following commands (<EXISTING_ENV_PATH> is path of your virtual environment):

cd <EXISTING_ENV_PATH>
rm .Python
rm bin/pip{,2,2.7}
rm bin/python{,2,2.7}
rm -r include/python2.7
rm lib/python2.7/*
rm -r lib/python2.7/distutils
rm lib/python2.7/site-packages/easy_install.*
rm -r lib/python2.7/site-packages/pip
rm -r lib/python2.7/site-packages/pip-*.dist-info
rm -r lib/python2.7/site-packages/setuptools
rm -r lib/python2.7/site-packages/setuptools-*.dist-info

Finally, re-create your virtual environment:

virtualenv <EXISTING_ENV_PATH>

By doing so, old Python core files and standard libraries (plus setuptools and pip) are removed, while the custom libraries installed in site-packages are preserved and working, as soon as they are in pure Python. Binary libraries may or may not need to be reinstalled to function properly.

This worked for me on 5 virtual environments with Django installed.

BTW, if ./manage.py compilemessages is not working afterwards, try this:

brew install gettext && brew link gettext --force

Reading from file using read() function

fgets would work for you. here is very good documentation on this :-
http://www.cplusplus.com/reference/cstdio/fgets/

If you don't want to use fgets, following method will work for you :-

int readline(FILE *f, char *buffer, size_t len)
{
   char c; 
   int i;

   memset(buffer, 0, len);

   for (i = 0; i < len; i++)
   {   
      int c = fgetc(f); 

      if (!feof(f)) 
      {   
         if (c == '\r')
            buffer[i] = 0;
         else if (c == '\n')
         {   
            buffer[i] = 0;

            return i+1;
         }   
         else
            buffer[i] = c; 
      }   
      else
      {   
         //fprintf(stderr, "read_line(): recv returned %d\n", c);
         return -1; 
      }   
   }   

   return -1; 
}

PDF files do not open in Internet Explorer with Adobe Reader 10.0 - users get an empty gray screen. How can I fix this for my users?

It's been 4 months since asking this question, and I still haven't found a good solution.
However, I did find a decent workaround, which I will share in case others have the same issue.
I will try to update this answer, too, if I make further progress.

First of all, my research has shown that there are several possible combinations of user-settings and site settings that cause a variety of PDF display issues. These include:

  • Broken version of Adobe Reader (10.0.*)
  • HTTPS site with Internet Explorer and the default setting "Don't save encrypted files to disk"
  • Adobe Reader setting - disable "Display PDF files in my browser"
  • Slow hardware (thanks @ahochhaus)

I spent some time researching PDF display options at pdfobject.com, which is an EXCELLENT resource and I learned a lot.

The workaround I came up with is to embed the PDF file inside an empty HTML page. It is very simple: See some similar examples at pdfobject.com.

<html>
    <head>...</head>
    <body>
        <object data="/pdf/sample.pdf" type="application/pdf" height="100%" width="100%"></object>
    </body>
</html>

However, here's a list of caveats:

  • This ignores all user-preferences for PDFs - for example, I personally like PDFs to open in a stand-alone Adobe Reader, but that is ignored
  • This doesn't work if you don't have the Adobe Reader plugin installed/enabled, so I added a "Get Adobe Reader" section to the html, and a link to download the file, which usually gets completely hidden by the <object /> tag, ... but ...
  • In Internet Explorer, if the plugin fails to load, the empty object will still hide the "Get Adobe Reader" section, so I had to set the z-index to show it ... but ...
  • Google Chrome's built-in PDF viewer also displays the "Get Adobe Reader" section on top of the PDF, so I had to do browser detection to determine whether to show the "Get Reader".

This is a huge list of caveats. I believe it covers all the bases, but I am definitely not comfortable applying this to EVERY user (most of whom do not have an issue).
Therefore, we decided to ONLY do this embedded option if the user opts-in for it. On our PDF page, we have a section that says "Having trouble viewing PDFs?", which lets you change your setting to "embedded", and we store that setting in a cookie.
In our GetPDF Action, we look for the embed=true cookie. This determines whether we return the PDF file, or if we return a View of HTML with the embedded PDF.

Ugh. This was even less fun than writing IE6-compatible JavaScript.
I hope that others with the same problem can find comfort knowing that they're not alone!

Find Java classes implementing an interface

If you were asking from the perspective of working this out with a running program then you need to look to the java.lang.* package. If you get a Class object, you can use the isAssignableFrom method to check if it is an interface of another Class.

There isn't a simple built in way of searching for these, tools like Eclipse build an index of this information.

If you don't have a specific list of Class objects to test you can look to the ClassLoader object, use the getPackages() method and build your own package hierarchy iterator.

Just a warning though that these methods and classes can be quite slow.

Get size of all tables in database

A small change on Mar_c's answer, since I have been going back to this page so often, ordered by most row's first:

SELECT
    t.NAME AS TableName,
    s.Name AS SchemaName,
    p.rows AS RowCounts,
    SUM(a.total_pages) * 8 AS TotalSpaceKB,
    SUM(a.used_pages) * 8 AS UsedSpaceKB,
    (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB
FROM
    sys.tables t
INNER JOIN
    sys.indexes i ON t.OBJECT_ID = i.object_id
INNER JOIN
    sys.partitions p ON i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN
    sys.allocation_units a ON p.partition_id = a.container_id
LEFT OUTER JOIN
    sys.schemas s ON t.schema_id = s.schema_id
WHERE
    t.NAME NOT LIKE 'dt%'
    AND t.is_ms_shipped = 0
    AND i.OBJECT_ID > 255
GROUP BY
    t.Name, s.Name, p.Rows
ORDER BY
    --p.rows DESC --Uncomment to order by amount rows instead of size in KB.
    SUM(a.total_pages) DESC 

SQL Update with row_number()

Your second attempt failed primarily because you named the CTE same as the underlying table and made the CTE look as if it was a recursive CTE, because it essentially referenced itself. A recursive CTE must have a specific structure which requires the use of the UNION ALL set operator.

Instead, you could just have given the CTE a different name as well as added the target column to it:

With SomeName As
(
SELECT 
CODE_DEST,
ROW_NUMBER() OVER (ORDER BY [RS_NOM] DESC) AS RN
FROM DESTINATAIRE_TEMP
)
UPDATE SomeName SET CODE_DEST=RN

What is the syntax for Typescript arrow functions with generics?

The full example explaining the syntax referenced by Robin... brought it home for me:

Generic functions

Something like the following works fine:

function foo<T>(x: T): T { return x; }

However using an arrow generic function will not:

const foo = <T>(x: T) => x; // ERROR : unclosed `T` tag

Workaround: Use extends on the generic parameter to hint the compiler that it's a generic, e.g.:

const foo = <T extends unknown>(x: T) => x;

Installing Git on Eclipse

egit was included in Indigo (2011) and should be there in all future Eclipse versions after that.

Just go to ![(Help->Install New Software)]

Then Work with: --All Available Sites--

Then type egit underneath and wait (may take a while) ! Then click the checkbox and install.

Can I access constants in settings.py from templates in Django?

Check out django-settings-export (disclaimer: I'm the author of this project).

For example...

$ pip install django-settings-export

settings.py

TEMPLATES = [
    {
        'OPTIONS': {
            'context_processors': [
                'django_settings_export.settings_export',
            ],
        },
    },
]

MY_CHEESE = 'Camembert';

SETTINGS_EXPORT = [
    'MY_CHEESE',
]

template.html

<script>var MY_CHEESE = '{{ settings.MY_CHEESE }}';</script>

C# switch statement limitations - why?

The first reason that comes to mind is historical:

Since most C, C++, and Java programmers are not accustomed to having such freedoms, they do not demand them.

Another, more valid, reason is that the language complexity would increase:

First of all, should the objects be compared with .Equals() or with the == operator? Both are valid in some cases. Should we introduce new syntax to do this? Should we allow the programmer to introduce their own comparison method?

In addition, allowing to switch on objects would break underlying assumptions about the switch statement. There are two rules governing the switch statement that the compiler would not be able to enforce if objects were allowed to be switched on (see the C# version 3.0 language specification, §8.7.2):

  • That the values of switch labels are constant
  • That the values of switch labels are distinct (so that only one switch block can be selected for a given switch-expression)

Consider this code example in the hypothetical case that non-constant case values were allowed:

void DoIt()
{
    String foo = "bar";
    Switch(foo, foo);
}

void Switch(String val1, String val2)
{
    switch ("bar")
    {
        // The compiler will not know that val1 and val2 are not distinct
        case val1:
            // Is this case block selected?
            break;
        case val2:
            // Or this one?
            break;
        case "bar":
            // Or perhaps this one?
            break;
    }
}

What will the code do? What if the case statements are reordered? Indeed, one of the reasons why C# made switch fall-through illegal is that the switch statements could be arbitrarily rearranged.

These rules are in place for a reason - so that the programmer can, by looking at one case block, know for certain the precise condition under which the block is entered. When the aforementioned switch statement grows into 100 lines or more (and it will), such knowledge is invaluable.

Inserting line breaks into PDF

$pdf->SetY($Y_Fields_Name_position);
$pdf->SetX(#);
$pdf->MultiCell($height,$width,"Line1 \nLine2 \nLine3",1,'C',1);

In every Column, before you set the X Position indicate first the Y position, so it became like this

Column 1

$pdf->SetY($Y_Fields_Name_position);
$pdf->SetX(#);
$pdf->MultiCell($height,$width,"Line1 \nLine2 \nLine3",1,'C',1);

Column 2

$pdf->SetY($Y_Fields_Name_position);
$pdf->SetX(#);
$pdf->MultiCell($height,$width,"Line1 \nLine2 \nLine3",1,'C',1);

Java compile error: "reached end of file while parsing }"

It happens when you don't properly close the code block:

if (condition){
  // your code goes here*
  { // This doesn't close the code block

Correct way:

if (condition){
  // your code goes here
} // Close the code block

What good technology podcasts are out there?

The SitePoint Podcast hosts are Patrick O’Keefe (@ifroggy), Stephan Segraves (@ssegraves), Brad Williams (@williamsba), and Kevin Yank (@sentience). (@%twitter username%)

Background color on input type=button :hover state sticks in IE

Try using the type attribute selector to find buttons (maybe this'll fix it too):

input[type=button]
{
  background-color: #E3E1B8; 
}

input[type=button]:hover
{
  background-color: #46000D
}

How to replace space with comma using sed?

IF your data includes an arbitrary sequence of blank characters (tab, space), and you want to replace each sequence with one comma, use the following:

sed 's/[\t ]+/,/g' input_file

or

sed -r 's/[[:blank:]]+/,/g' input_file

If you want to replace sequence of space characters, which includes other characters such as carriage return and backspace, etc, then use the following:

sed -r 's/[[:space:]]+/,/g' input_file

How to get to a particular element in a List in java?

You have about 98% right. The only issue is that you're trying to print out an String[] which does not print the way you'd like. Instead try this...

for (String[] s : myEntries) {
    System.out.print("Next item: " + s[0]);
    for(int i = 1; i < s.length; i++) {
        System.out.print(", " + s[i]);
    }
    System.out.println("");
}

This way you're accessing each string in the array instead of the array itself.

Hope this helps!

how to change attribute "hidden" in jquery

A. Wolff was leading you in the right direction. There are several attributes where you should not be setting a string value. You must toggle it with a boolean true or false.

.attr("hidden", false) will remove the attribute the same as using .removeAttr("hidden").

.attr("hidden", "false") is incorrect and the tag remains hidden.

You should not be setting hidden, checked, selected, or several others to any string value to toggle it.

How to resolve "The requested URL was rejected. Please consult with your administrator." error?

I have faced the same issue using Google Chrome browser. Same website was opening normally using the incognito mode and different browsers. At first, I cleared cached files and cookies over the past 24 hours, but this didn't help.

I realized that my first visit to the website was during the past 10 days. So, I cleared cached files and cookies over the past 4 weeks and that resolved the problem.
Note: I didn't clear my browsing history data

Can not deserialize instance of java.lang.String out of START_ARRAY token

The error is:

Can not deserialize instance of java.lang.String out of START_ARRAY token at [Source: line: 1, column: 1095] (through reference chain: JsonGen["platforms"])

In JSON, platforms look like this:

"platforms": [
    {
        "platform": "iphone"
    },
    {
        "platform": "ipad"
    },
    {
        "platform": "android_phone"
    },
    {
        "platform": "android_tablet"
    }
]

So try change your pojo to something like this:

private List platforms;

public List getPlatforms(){
    return this.platforms;
}

public void setPlatforms(List platforms){
    this.platforms = platforms;
}

EDIT: you will need change mobile_networks too. Will look like this:

private List mobile_networks;

public List getMobile_networks() {
    return mobile_networks;
}

public void setMobile_networks(List mobile_networks) {
    this.mobile_networks = mobile_networks;
}

HTML Display Current date

This helped me:

<p>Date/Time: <span id="datetime"></span></p><script>var dt = new Date();
document.getElementById("datetime").innerHTML=dt.toLocaleString();</script>    

Tomcat Servlet: Error 404 - The requested resource is not available

You have to user ../../projectName/Filename.jsp in your action attr. or href

../ = contains current folder simple(demo.project.filename.jsp)

Servlet can only be called with 1 slash forward to your project name..

mcrypt is deprecated, what is the alternative?

Pure-PHP implementation of Rijndael exists with phpseclib available as composer package and works on PHP 7.3 (tested by me).

There's a page on the phpseclib docs, which generates sample code after you input the basic variables (cipher, mode, key size, bit size). It outputs the following for Rijndael, ECB, 256, 256:

a code with mycrypt

$decoded = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, ENCRYPT_KEY, $term, MCRYPT_MODE_ECB);

works like this with the library

$rijndael = new \phpseclib\Crypt\Rijndael(\phpseclib\Crypt\Rijndael::MODE_ECB);
$rijndael->setKey(ENCRYPT_KEY);
$rijndael->setKeyLength(256);
$rijndael->disablePadding();
$rijndael->setBlockLength(256);

$decoded = $rijndael->decrypt($term);

* $term was base64_decoded

How can I pass a parameter to a setTimeout() callback?

// These are three very simple and concise answers:

function fun() {
    console.log(this.prop1, this.prop2, this.prop3);
}

let obj = { prop1: 'one', prop2: 'two', prop3: 'three' };

let bound = fun.bind(obj);

setTimeout(bound, 3000);

 // or

function funOut(par1, par2, par3) {

  return function() { 

    console.log(par1, par2, par3);

  }
};

setTimeout(funOut('one', 'two', 'three'), 5000);

 // or

let funny = function(a, b, c) { console.log(a, b, c); };

setTimeout(funny, 2000, 'hello', 'worldly', 'people');

Comparison of full text search engine - Lucene, Sphinx, Postgresql, MySQL?

Good to see someone's chimed in about Lucene - because I've no idea about that.

Sphinx, on the other hand, I know quite well, so let's see if I can be of some help.

  • Result relevance ranking is the default. You can set up your own sorting should you wish, and give specific fields higher weightings.
  • Indexing speed is super-fast, because it talks directly to the database. Any slowness will come from complex SQL queries and un-indexed foreign keys and other such problems. I've never noticed any slowness in searching either.
  • I'm a Rails guy, so I've no idea how easy it is to implement with Django. There is a Python API that comes with the Sphinx source though.
  • The search service daemon (searchd) is pretty low on memory usage - and you can set limits on how much memory the indexer process uses too.
  • Scalability is where my knowledge is more sketchy - but it's easy enough to copy index files to multiple machines and run several searchd daemons. The general impression I get from others though is that it's pretty damn good under high load, so scaling it out across multiple machines isn't something that needs to be dealt with.
  • There's no support for 'did-you-mean', etc - although these can be done with other tools easily enough. Sphinx does stem words though using dictionaries, so 'driving' and 'drive' (for example) would be considered the same in searches.
  • Sphinx doesn't allow partial index updates for field data though. The common approach to this is to maintain a delta index with all the recent changes, and re-index this after every change (and those new results appear within a second or two). Because of the small amount of data, this can take a matter of seconds. You will still need to re-index the main dataset regularly though (although how regularly depends on the volatility of your data - every day? every hour?). The fast indexing speeds keep this all pretty painless though.

I've no idea how applicable to your situation this is, but Evan Weaver compared a few of the common Rails search options (Sphinx, Ferret (a port of Lucene for Ruby) and Solr), running some benchmarks. Could be useful, I guess.

I've not plumbed the depths of MySQL's full-text search, but I know it doesn't compete speed-wise nor feature-wise with Sphinx, Lucene or Solr.

How to state in requirements.txt a direct github source

First, install with git+git or git+https, in any way you know. Example of installing kronok's branch of the brabeion project:

pip install -e git+https://github.com/kronok/brabeion.git@12efe6aa06b85ae5ff725d3033e38f624e0a616f#egg=brabeion

Second, use pip freeze > requirements.txt to get the right thing in your requirements.txt. In this case, you will get

-e git+https://github.com/kronok/brabeion.git@12efe6aa06b85ae5ff725d3033e38f624e0a616f#egg=brabeion-master

Third, test the result:

pip uninstall brabeion
pip install -r requirements.txt

PHP Foreach Arrays and objects

Looping over arrays and objects is a pretty common task, and it's good that you're wanting to learn how to do it. Generally speaking you can do a foreach loop which cycles over each member, assigning it a new temporary name, and then lets you handle that particular member via that name:

foreach ($arr as $item) {
    echo $item->sm_id;
}

In this example each of our values in the $arr will be accessed in order as $item. So we can print our values directly off of that. We could also include the index if we wanted:

foreach ($arr as $index => $item) {
    echo "Item at index {$index} has sm_id value {$item->sm_id}";
}

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

There is this function scandir():

$dir = 'dir';
$files = scandir($dir, 0);
for($i = 2; $i < count($files); $i++)
    print $files[$i]."<br>";

More here in the php.net manual

Split string on the first white space occurrence

Javascript doesn't support lookbehinds, so split is not possible. match works:

str.match(/^(\S+)\s(.*)/).slice(1)

Another trick:

str.replace(/\s+/, '\x01').split('\x01')

how about:

[str.replace(/\s.*/, ''), str.replace(/\S+\s/, '')]

and why not

reverse = function (s) { return s.split('').reverse().join('') }
reverse(str).split(/\s(?=\S+$)/).reverse().map(reverse)

or maybe

re = /^\S+\s|.*/g;
[].concat.call(re.exec(str), re.exec(str))

2019 update: as of ES2018, lookbehinds are supported:

_x000D_
_x000D_
str = "72 tocirah sneab"_x000D_
s = str.split(/(?<=^\S+)\s/)_x000D_
console.log(s)
_x000D_
_x000D_
_x000D_

Can I make dynamic styles in React Native?

Had some issue syntactically. This worked for me

<Text style={[styles.textStyle,{color: 'red'}]}> Hello </Text>

const styles = StyleSheet.create({
   textStyle :{
      textAlign: 'center',   
      fontFamily: 'Arial',
      fontSize: 16
  }
  });

Saving a Numpy array as an image

Addendum to @ideasman42's answer:

def saveAsPNG(array, filename):
    import struct
    if any([len(row) != len(array[0]) for row in array]):
        raise ValueError, "Array should have elements of equal size"

                                #First row becomes top row of image.
    flat = []; map(flat.extend, reversed(array))
                                 #Big-endian, unsigned 32-byte integer.
    buf = b''.join([struct.pack('>I', ((0xffFFff & i32)<<8)|(i32>>24) )
                    for i32 in flat])   #Rotate from ARGB to RGBA.

    data = write_png(buf, len(array[0]), len(array))
    f = open(filename, 'wb')
    f.write(data)
    f.close()

So you can do:

saveAsPNG([[0xffFF0000, 0xffFFFF00],
           [0xff00aa77, 0xff333333]], 'test_grid.png')

Producing test_grid.png:

Grid of red, yellow, dark-aqua, grey

(Transparency also works, by reducing the high byte from 0xff.)

What does it mean when Statement.executeUpdate() returns -1?

As the statement executed is not actually DML (eg UPDATE, INSERT or EXECUTE), but a piece of T-SQL which contains DML, I suspect it is not treated as an update-query.

Section 13.1.2.3 of the JDBC 4.1 specification states something (rather hard to interpret btw):

When the method execute returns true, the method getResultSet is called to retrieve the ResultSet object. When execute returns false, the method getUpdateCount returns an int. If this number is greater than or equal to zero, it indicates the update count returned by the statement. If it is -1, it indicates that there are no more results.

Given this information, I guess that executeUpdate() internally does an execute(), and then - as execute() will return false - it will return the value of getUpdateCount(), which in this case - in accordance with the JDBC spec - will return -1.

This is further corroborated by the fact 1) that the Javadoc for Statement.executeUpdate() says:

Returns: either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0 for SQL statements that return nothing

And 2) that the Javadoc for Statement.getUpdateCount() specifies:

the current result as an update count; -1 if the current result is a ResultSet object or there are no more results

Just to clarify: given the Javadoc for executeUpdate() the behavior is probably wrong, but it can be explained.

Also as I commented elsewhere, the -1 might just indicate: maybe something was changed, but we simply don't know, or we can't give an accurate number of changes (eg because in this example it is a piece of T-SQL that is executed).

Java Web Service client basic authentication

Some context additional about basic authentication, it consists in a header which contains the key/value pair:

Authorization: Basic Z2VybWFuOmdlcm1hbg==

where "Authorization" is the headers key, and the headers value has a string ( "Basic" word plus blank space) concatenated to "Z2VybWFuOmdlcm1hbg==", which are the user and password in base 64 joint by double dot

String name = "username";
String password = "secret";
String authString = name + ":" + password;
String authStringEnc = new BASE64Encoder().encode(authString.getBytes());
...
objectXXX.header("Authorization", "Basic " + authStringEnc);

How to disable button in React.js

this.input is undefined until the ref callback is called. Try setting this.input to some initial value in your constructor.

From the React docs on refs, emphasis mine:

the callback will be executed immediately after the component is mounted or unmounted

New to unit testing, how to write great tests?

It's worth noting that retro-fitting unit tests into existing code is far more difficult than driving the creation of that code with tests in the first place. That's one of the big questions in dealing with legacy applications... how to unit test? This has been asked many times before (so you may be closed as a dupe question), and people usually end up here:

Moving existing code to Test Driven Development

I second the accepted answer's book recommendation, but beyond that there's more information linked in the answers there.

JavaScript load a page on button click

Simple code to redirect page

<!-- html button designing and calling the event in javascript -->
<input id="btntest" type="button" value="Check" 
       onclick="window.location.href = 'http://www.google.com'" />

How to initialize a static array?

Nope, no difference. It's just syntactic sugar. Arrays.asList(..) creates an additional list.

How to check a not-defined variable in JavaScript

In JavaScript, null is an object. There's another value for things that don't exist, undefined. The DOM returns null for almost all cases where it fails to find some structure in the document, but in JavaScript itself undefined is the value used.

Second, no, there is not a direct equivalent. If you really want to check for specifically for null, do:

if (yourvar === null) // Does not execute if yourvar is `undefined`

If you want to check if a variable exists, that can only be done with try/catch, since typeof will treat an undeclared variable and a variable declared with the value of undefined as equivalent.

But, to check if a variable is declared and is not undefined:

if (yourvar !== undefined) // Any scope

Previously, it was necessary to use the typeof operator to check for undefined safely, because it was possible to reassign undefined just like a variable. The old way looked like this:

if (typeof yourvar !== 'undefined') // Any scope

The issue of undefined being re-assignable was fixed in ECMAScript 5, which was released in 2009. You can now safely use === and !== to test for undefined without using typeof as undefined has been read-only for some time.

If you want to know if a member exists independent but don't care what its value is:

if ('membername' in object) // With inheritance
if (object.hasOwnProperty('membername')) // Without inheritance

If you want to to know whether a variable is truthy:

if (yourvar)

Source

how do I get a new line, after using float:left?

Another approach that's a little more semantic is to have a UL defined as your total 6 image width, each LI defined as float left and width defined - so that when LI #7 hits, it runs into the boundry of the UL, and is pushed down to the new row. You'll still have an open float that you'll want to clear after the /UL - but that can be done on the next element of the page, or as a clear div. Here's sort of the idea, you may have to mess with actual values, but this should give you the idea. The code is a little cleaner.

 <style type="text/css"> 
ul#imageSet { width: 600px; margin: 0; padding:0; }
ul#imageSet li { float: left; width: 100px;  height: 188px; margin: 0; padding:0; position: relative; list-style-type: none; }
.cornerimage { position: absolute; bottom: 0; right: 0; } 
h3.nextelement { clear: both; }
</style>


<ul id="imageSet">
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
     <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
    <li>
        <img border="0" height="188" src="http://farm3.static.flickr.com/2459/3534790964_5d8bed17c0.jpg" width="100" />
        <img class="cornerimage" height="140" src="http://farm4.static.flickr.com/3310/3514664446_08e9745681.jpg" width="50" />
    </li>
</ul>


<h3 class="nextelement">Next Element in Doc</h3>

Custom toast on Android: a simple example

STEP 1:

First create a layout for a custom toast in res/layout/custom_toast.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/custom_toast_layout_id"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#FFF"
    android:orientation="horizontal"
    android:padding="5dp" >

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:textColor="#000" />

</LinearLayout>

STEP 2: In the Activity code, get the above custom view and attach to Toast:

// Get your custom_toast.xml ayout
LayoutInflater inflater = getLayoutInflater();

View layout = inflater.inflate(R.layout.custom_toast,
(ViewGroup) findViewById(R.id.custom_toast_layout_id));

// set a message
TextView text = (TextView) layout.findViewById(R.id.text);
text.setText("Button is clicked!");

// Toast...
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.setDuration(Toast.LENGTH_LONG);
toast.setView(layout);
toast.show();

For more help see how we Create custom Toast in Android:

http://developer.android.com/guide/topics/ui/notifiers/toasts.html

CORS error :Request header field Authorization is not allowed by Access-Control-Allow-Headers in preflight response

For anyone getting this using ServiceStack backend; add "Authorization" to allowed headers in the Cors plugin:

Plugins.Add(new CorsFeature(allowedHeaders: "Content-Type,Authorization"));

React.js: Wrapping one component into another

Try:

var Wrapper = React.createClass({
  render: function() {
    return (
      <div className="wrapper">
        before
          {this.props.children}
        after
      </div>
    );
  }
});

See Multiple Components: Children and Type of the Children props in the docs for more info.

MySQL CREATE TABLE IF NOT EXISTS in PHPmyadmin import

On the CREATE TABLE,

The AUTO_INCREMENT of abuse_id is set to 2. MySQL now thinks 1 already exists.

With the INSERT statement you are trying to insert abuse_id with record 1. Please set AUTO_INCREMENT on CREATE_TABLE to 1 and try again.

Otherwise set the abuse_id in the INSERT statement to 'NULL'.

How can i resolve this?

load iframe in bootstrap modal

I came across this implementation in Codepen. I hope you find it helpful.

this.on('hidden.bs.modal', function(){
      $(this).find('iframe').html("").attr("src", "");
    });

Wait for all promises to resolve

The accepted answer is correct. I would like to provide an example to elaborate it a bit to those who aren't familiar with promise.

Example:

In my example, I need to replace the src attributes of img tags with different mirror urls if available before rendering the content.

var img_tags = content.querySelectorAll('img');

function checkMirrorAvailability(url) {

    // blah blah 

    return promise;
}

function changeSrc(success, y, response) {
    if (success === true) {
        img_tags[y].setAttribute('src', response.mirror_url);
    } 
    else {
        console.log('No mirrors for: ' + img_tags[y].getAttribute('src'));
    }
}

var promise_array = [];

for (var y = 0; y < img_tags.length; y++) {
    var img_src = img_tags[y].getAttribute('src');

    promise_array.push(
        checkMirrorAvailability(img_src)
        .then(

            // a callback function only accept ONE argument. 
            // Here, we use  `.bind` to pass additional arguments to the
            // callback function (changeSrc).

            // successCallback
            changeSrc.bind(null, true, y),
            // errorCallback
            changeSrc.bind(null, false, y)
        )
    );
}

$q.all(promise_array)
.then(
    function() {
        console.log('all promises have returned with either success or failure!');
        render(content);
    }
    // We don't need an errorCallback function here, because above we handled
    // all errors.
);

Explanation:

From AngularJS docs:

The then method:

then(successCallback, errorCallback, notifyCallback) – regardless of when the promise was or will be resolved or rejected, then calls one of the success or error callbacks asynchronously as soon as the result is available. The callbacks are called with a single argument: the result or rejection reason.

$q.all(promises)

Combines multiple promises into a single promise that is resolved when all of the input promises are resolved.

The promises param can be an array of promises.

About bind(), More info here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind

How can I see the raw SQL queries Django is running?

For Django 2.2:

As most of the answers did not helped me much when using ./manage.py shell. Finally i found the answer. Hope this helps to someone.

To view all the queries:

from django.db import connection
connection.queries

To view query for a single query:

q=Query.objects.all()
q.query.__str__()

q.query just displaying the object for me. Using the __str__()(String representation) displayed the full query.

Converting bool to text in C++

How about the simple:

constexpr char const* toString(bool b)
{
   return b ? "true" : "false";
}

Most efficient way to append arrays in C#?

You might not need to concatenate end result into contiguous array. Instead, keep appending to the list as suggested by Jon. In the end you'll have a jagged array (well, almost rectangular in fact). When you need to access an element by index, use following indexing scheme:

double x = list[i / sampleSize][i % sampleSize];

Iteration over jagged array is also straightforward:

for (int iRow = 0; iRow < list.Length; ++iRow) {
  double[] row = list[iRow];
  for (int iCol = 0; iCol < row.Length; ++iCol) {
    double x = row[iCol];
  }
}

This saves you memory allocation and copying at expense of slightly slower element access. Whether this will be a net performance gain depends on size of your data, data access patterns and memory constraints.

How do I create a new Git branch from an old commit?

git checkout -b NEW_BRANCH_NAME COMMIT_ID

This will create a new branch called 'NEW_BRANCH_NAME' and check it out.

("check out" means "to switch to the branch")

git branch NEW_BRANCH_NAME COMMIT_ID

This just creates the new branch without checking it out.


in the comments many people seem to prefer doing this in two steps. here's how to do so in two steps:

git checkout COMMIT_ID
# you are now in the "detached head" state
git checkout -b NEW_BRANCH_NAME

How does MySQL process ORDER BY and LIMIT in a query?

It will order first, then get the first 20. A database will also process anything in the WHERE clause before ORDER BY.

How to convert numpy arrays to standard TensorFlow format?

You can use tf.pack (tf.stack in TensorFlow 1.0.0) method for this purpose. Here is how to pack a random image of type numpy.ndarray into a Tensor:

import numpy as np
import tensorflow as tf
random_image = np.random.randint(0,256, (300,400,3))
random_image_tensor = tf.pack(random_image)
tf.InteractiveSession()
evaluated_tensor = random_image_tensor.eval()

UPDATE: to convert a Python object to a Tensor you can use tf.convert_to_tensor function.

How to make a .jar out from an Android Studio project

  1. Go to Gradle tab in Android Studio , then select library project .

  2. Then go to Tasks

  3. Then go to Other

  4. Double click on bundleReleaseaar

You can find your .aar files under your_module/build/outputs/aar/your-release.aar

Here image

File uploading with Express 4.0: req.files undefined

It looks like body-parser did support uploading files in Express 3, but support was dropped for Express 4 when it no longer included Connect as a dependency

After looking through some of the modules in mscdex's answer, I found that express-busboy was a far better alternative and the closest thing to a drop-in replacement. The only differences I noticed were in the properties of the uploaded file.

console.log(req.files) using body-parser (Express 3) output an object that looked like this:

{ file: 
   { fieldName: 'file',
     originalFilename: '360px-Cute_Monkey_cropped.jpg',
     name: '360px-Cute_Monkey_cropped.jpg'
     path: 'uploads/6323-16v7rc.jpg',
     type: 'image/jpeg',
     headers: 
      { 'content-disposition': 'form-data; name="file"; filename="360px-Cute_Monkey_cropped.jpg"',
        'content-type': 'image/jpeg' },
     ws: 
      WriteStream { /* ... */ },
     size: 48614 } }

compared to console.log(req.files) using express-busboy (Express 4):

{ file: 
   { field: 'file',
     filename: '360px-Cute_Monkey_cropped.jpg',
     file: 'uploads/9749a8b6-f9cc-40a9-86f1-337a46e16e44/file/360px-Cute_Monkey_cropped.jpg',
     mimetype: 'image/jpeg',
     encoding: '7bit',
     truncated: false
     uuid: '9749a8b6-f9cc-40a9-86f1-337a46e16e44' } }

curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

Simple answer

If you are behind a proxy server, please set the proxy for curl. The curl is not able to connect to server so it shows wrong version number. Set proxy by opening subl ~/.curlrc or use any other text editor. Then add the following line to file: proxy= proxyserver:proxyport For e.g. proxy = 10.8.0.1:8080

If you are not behind a proxy, make sure that the curlrc file does not contain the proxy settings.

How to list the certificates stored in a PKCS12 keystore with keytool?

If the keystore is PKCS12 type (.pfx) you have to specify it with -storetype PKCS12 (line breaks added for readability):

keytool -list -v -keystore <path to keystore.pfx> \
    -storepass <password> \
    -storetype PKCS12

How do you install Google frameworks (Play, Accounts, etc.) on a Genymotion virtual device?

If anyone got an error while signing in to Google and this message appear:

Couldn't Sign In
can't establish a reliable connection to the server...

then try to sign in from the browser - in YouTube, Gmail, Google sites, etc.

This helped me. After signing in in the browser I was able to sign in the Google Play app...

do { ... } while (0) — what is it good for?

It's the only construct in C that you can use to #define a multistatement operation, put a semicolon after, and still use within an if statement. An example might help:

#define FOO(x) foo(x); bar(x)

if (condition)
    FOO(x);
else // syntax error here
    ...;

Even using braces doesn't help:

#define FOO(x) { foo(x); bar(x); }

Using this in an if statement would require that you omit the semicolon, which is counterintuitive:

if (condition)
    FOO(x)
else
    ...

If you define FOO like this:

#define FOO(x) do { foo(x); bar(x); } while (0)

then the following is syntactically correct:

if (condition)
    FOO(x);
else
    ....

VBA Public Array : how to?

Option Explicit
     Public myarray (1 To 10)
     Public Count As Integer
     myarray(1) = "A"
     myarray(2) = "B"
     myarray(3) = "C"
     myarray(4) = "D"
     myarray(5) = "E"
     myarray(6) = "F"
     myarray(7) = "G"
     myarray(8) = "H"
     myarray(9) = "I"
     myarray(10) = "J"
Private Function unwrapArray()
     For Count = 1 to UBound(myarray)
       MsgBox "Letters of the Alphabet : " & myarray(Count)
     Next 
End Function

Download and open PDF file using Ajax

_x000D_
_x000D_
var xhr;_x000D_
var beforeSend = function(){_x000D_
    $('#pleasewaitDL').modal('show');_x000D_
}_x000D_
$(function () {_x000D_
    $('#print_brochure_link').click(function(){_x000D_
        beforeSend();_x000D_
        xhr = new XMLHttpRequest();_x000D_
        xhr.open("GET",$('#preparedPrintModalForm').attr('action'), true); _x000D_
        xhr.responseType = "blob";_x000D_
        xhr.onload = function (e) {_x000D_
            if (this.status === 200) {_x000D_
                var file = window.URL.createObjectURL(this.response);_x000D_
                var a = document.createElement("a");_x000D_
                a.href = file;_x000D_
                a.download = this.response.name || "Property Brochure";_x000D_
                console.log(file);_x000D_
                document.body.appendChild(a);_x000D_
                a.click();_x000D_
                _x000D_
                window.onfocus = function () {                     _x000D_
                  document.body.removeChild(a)_x000D_
                }_x000D_
                $('#pleasewaitDL').modal('hide');_x000D_
            };_x000D_
        };_x000D_
        xhr.send($('#preparedPrintModalForm').serialize());_x000D_
    });_x000D_
    $('#pleasewaitDLCancel').click(function() {_x000D_
        xhr.abort();_x000D_
    });_x000D_
});
_x000D_
_x000D_
_x000D_

Add a user control to a wpf window

Make sure there is an namespace definition (xmlns) for the namespace your control belong to.

xmlns:myControls="clr-namespace:YourCustomNamespace.Controls;assembly=YourAssemblyName"
<myControls:thecontrol/>

how to display none through code behind

try this

<div id="login_div" runat="server">

and on the code behind.

login_div.Style.Add("display", "none");

Interface extends another interface but implements its methods

An interface defines behavior. For example, a Vehicle interface might define the move() method.

A Car is a Vehicle, but has additional behavior. For example, the Car interface might define the startEngine() method. Since a Car is also a Vehicle, the Car interface extends the Vehicle interface, and thus defines two methods: move() (inherited) and startEngine().

The Car interface doesn't have any method implementation. If you create a class (Volkswagen) that implements Car, it will have to provide implementations for all the methods of its interface: move() and startEngine().

An interface may not implement any other interface. It can only extend it.

Understanding passport serialize deserialize

  1. Where does user.id go after passport.serializeUser has been called?

The user id (you provide as the second argument of the done function) is saved in the session and is later used to retrieve the whole object via the deserializeUser function.

serializeUser determines which data of the user object should be stored in the session. The result of the serializeUser method is attached to the session as req.session.passport.user = {}. Here for instance, it would be (as we provide the user id as the key) req.session.passport.user = {id: 'xyz'}

  1. We are calling passport.deserializeUser right after it where does it fit in the workflow?

The first argument of deserializeUser corresponds to the key of the user object that was given to the done function (see 1.). So your whole object is retrieved with help of that key. That key here is the user id (key can be any key of the user object i.e. name,email etc). In deserializeUser that key is matched with the in memory array / database or any data resource.

The fetched object is attached to the request object as req.user

Visual Flow

passport.serializeUser(function(user, done) {
    done(null, user.id);
});              ¦
                 ¦ 
                 ¦
                 +--------------------? saved to session
                                   ¦    req.session.passport.user = {id: '..'}
                                   ¦
                                   ?           
passport.deserializeUser(function(id, done) {
                   +---------------+
                   ¦
                   ? 
    User.findById(id, function(err, user) {
        done(err, user);
    });            +--------------? user object attaches to the request as req.user   
});

How to remove all leading zeroes in a string

Assuming you want a run-on of three or more zeros to be removed and your example is one string:

    $test_str ="0002030050400000234892839000239074";
    $fixed_str = preg_replace('/000+/','',$test_str);

You can make the regex pattern fit what you need if my assumptions are off.

This help?

How to make a checkbox checked with jQuery?

$('#test').attr('checked','checked');

$('#test').removeAttr('checked');

How to access parent scope from within a custom directive *with own scope* in AngularJS?

If you are using ES6 Classes and ControllerAs syntax, you need to do something slightly different.

See the snippet below and note that vm is the ControllerAs value of the parent Controller as used in the parent HTML

myApp.directive('name', function() {
  return {
    // no scope definition
    link : function(scope, element, attrs, ngModel) {

        scope.vm.func(...)

SQL to LINQ Tool

Edit 7/17/2020: I cannot delete this accepted answer. It used to be good, but now it isn't. Beware really old posts, guys. I'm removing the link.

[Linqer] is a SQL to LINQ converter tool. It helps you to learn LINQ and convert your existing SQL statements.

Not every SQL statement can be converted to LINQ, but Linqer covers many different types of SQL expressions. Linqer supports both .NET languages - C# and Visual Basic.

Python data structure sort list alphabetically

[] denotes a list, () denotes a tuple and {} denotes a dictionary. You should take a look at the official Python tutorial as these are the very basics of programming in Python.

What you have is a list of strings. You can sort it like this:

In [1]: lst = ['Stem', 'constitute', 'Sedge', 'Eflux', 'Whim', 'Intrigue']

In [2]: sorted(lst)
Out[2]: ['Eflux', 'Intrigue', 'Sedge', 'Stem', 'Whim', 'constitute']

As you can see, words that start with an uppercase letter get preference over those starting with a lowercase letter. If you want to sort them independently, do this:

In [4]: sorted(lst, key=str.lower)
Out[4]: ['constitute', 'Eflux', 'Intrigue', 'Sedge', 'Stem', 'Whim']

You can also sort the list in reverse order by doing this:

In [12]: sorted(lst, reverse=True)
Out[12]: ['constitute', 'Whim', 'Stem', 'Sedge', 'Intrigue', 'Eflux']

In [13]: sorted(lst, key=str.lower, reverse=True)
Out[13]: ['Whim', 'Stem', 'Sedge', 'Intrigue', 'Eflux', 'constitute']

Please note: If you work with Python 3, then str is the correct data type for every string that contains human-readable text. However, if you still need to work with Python 2, then you might deal with unicode strings which have the data type unicode in Python 2, and not str. In such a case, if you have a list of unicode strings, you must write key=unicode.lower instead of key=str.lower.

What's the difference between Invoke() and BeginInvoke()

Do you mean Delegate.Invoke/BeginInvoke or Control.Invoke/BeginInvoke?

  • Delegate.Invoke: Executes synchronously, on the same thread.
  • Delegate.BeginInvoke: Executes asynchronously, on a threadpool thread.
  • Control.Invoke: Executes on the UI thread, but calling thread waits for completion before continuing.
  • Control.BeginInvoke: Executes on the UI thread, and calling thread doesn't wait for completion.

Tim's answer mentions when you might want to use BeginInvoke - although it was mostly geared towards Delegate.BeginInvoke, I suspect.

For Windows Forms apps, I would suggest that you should usually use BeginInvoke. That way you don't need to worry about deadlock, for example - but you need to understand that the UI may not have been updated by the time you next look at it! In particular, you shouldn't modify data which the UI thread might be about to use for display purposes. For example, if you have a Person with FirstName and LastName properties, and you did:

person.FirstName = "Kevin"; // person is a shared reference
person.LastName = "Spacey";
control.BeginInvoke(UpdateName);
person.FirstName = "Keyser";
person.LastName = "Soze";

Then the UI may well end up displaying "Keyser Spacey". (There's an outside chance it could display "Kevin Soze" but only through the weirdness of the memory model.)

Unless you have this sort of issue, however, Control.BeginInvoke is easier to get right, and will avoid your background thread from having to wait for no good reason. Note that the Windows Forms team has guaranteed that you can use Control.BeginInvoke in a "fire and forget" manner - i.e. without ever calling EndInvoke. This is not true of async calls in general: normally every BeginXXX should have a corresponding EndXXX call, usually in the callback.

adb shell command to make Android package uninstall dialog appear

Use this command in cmd:

adb shell pm uninstall -k com.packagename

For example:

adb shell pm uninstall -k com.fedmich.pagexray

The -k flag tells the package manager to keep the cache and data directories around, even though the app is removed. If you want a clean uninstall, don't specify -k.

python requests get cookies

Alternatively, you can use requests.Session and observe cookies before and after a request:

>>> import requests
>>> session = requests.Session()
>>> print(session.cookies.get_dict())
{}
>>> response = session.get('http://google.com')
>>> print(session.cookies.get_dict())
{'PREF': 'ID=5514c728c9215a9a:FF=0:TM=1406958091:LM=1406958091:S=KfAG0U9jYhrB0XNf', 'NID': '67=TVMYiq2wLMNvJi5SiaONeIQVNqxSc2RAwVrCnuYgTQYAHIZAGESHHPL0xsyM9EMpluLDQgaj3db_V37NjvshV-eoQdA8u43M8UwHMqZdL-S2gjho8j0-Fe1XuH5wYr9v'}

Is there a 'box-shadow-color' property?

Yes there is a way

box-shadow 0 0 17px 13px rgba(30,140,255,0.80) inset

How to join components of a path when you are constructing a URL in Python

The basejoin function in the urllib package might be what you're looking for.

basejoin = urljoin(base, url, allow_fragments=True)
    Join a base URL and a possibly relative URL to form an absolute
    interpretation of the latter.

Edit: I didn't notice before, but urllib.basejoin seems to map directly to urlparse.urljoin, making the latter preferred.

How to include files outside of Docker's build context?

I had this same issue with a project and some data files that I wasn't able to move inside the repo context for HIPAA reasons. I ended up using 2 Dockerfiles. One builds the main application without the stuff I needed outside the container and publishes that to internal repo. Then a second dockerfile pulls that image and adds the data and creates a new image which is then deployed and never stored anywhere. Not ideal, but it worked for my purposes of keeping sensitive information out of the repo.

JOptionPane - input dialog box program

Why to annoy the user with three different Dialog Boxes to enter things, why not do all this in one go in a single Dialog and save time, instead of testing the patience of the USER ?

You can add everything in a single Dialog, by putting all the fields on your JPanel and then adding this JPanel to your JOptionPane. Below code can clarify a bit more :

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

public class AverageExample
{
    private double[] marks;
    private JTextField[] marksField;
    private JLabel resultLabel;

    public AverageExample()
    {
        marks = new double[3];
        marksField = new JTextField[3];
        marksField[0] = new JTextField(10);
        marksField[1] = new JTextField(10);
        marksField[2] = new JTextField(10);
    }

    private void displayGUI()
    {
        int selection = JOptionPane.showConfirmDialog(
                null, getPanel(), "Input Form : "
                                , JOptionPane.OK_CANCEL_OPTION
                                , JOptionPane.PLAIN_MESSAGE);

        if (selection == JOptionPane.OK_OPTION) 
        {
            for ( int i = 0; i < 3; i++)
            {
                marks[i] = Double.valueOf(marksField[i].getText());             
            }
            Arrays.sort(marks);
            double average = (marks[1] + marks[2]) / 2.0;
            JOptionPane.showMessageDialog(null
                    , "Average is : " + Double.toString(average)
                    , "Average : "
                    , JOptionPane.PLAIN_MESSAGE);
        }
        else if (selection == JOptionPane.CANCEL_OPTION)
        {
            // Do something here.
        }
    }

    private JPanel getPanel()
    {
        JPanel basePanel = new JPanel();
        //basePanel.setLayout(new BorderLayout(5, 5));
        basePanel.setOpaque(true);
        basePanel.setBackground(Color.BLUE.darker());

        JPanel centerPanel = new JPanel();
        centerPanel.setLayout(new GridLayout(3, 2, 5, 5));
        centerPanel.setBorder(
            BorderFactory.createEmptyBorder(5, 5, 5, 5));
        centerPanel.setOpaque(true);
        centerPanel.setBackground(Color.WHITE);

        JLabel mLabel1 = new JLabel("Enter Marks 1 : ");
        JLabel mLabel2 = new JLabel("Enter Marks 2 : ");
        JLabel mLabel3 = new JLabel("Enter Marks 3 : ");

        centerPanel.add(mLabel1);
        centerPanel.add(marksField[0]);
        centerPanel.add(mLabel2);
        centerPanel.add(marksField[1]);
        centerPanel.add(mLabel3);
        centerPanel.add(marksField[2]);

        basePanel.add(centerPanel);

        return basePanel;
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                new AverageExample().displayGUI();
            }
        });
    }
}

Make a bucket public in Amazon S3

Amazon provides a policy generator tool:

https://awspolicygen.s3.amazonaws.com/policygen.html

After that, you can enter the policy requirements for the bucket on the AWS console:

https://console.aws.amazon.com/s3/home

How to add new item to hash

hash.store(key, value) - Stores a key-value pair in hash.

Example:

hash   #=> {"a"=>9, "b"=>200, "c"=>4}
hash.store("d", 42) #=> 42
hash   #=> {"a"=>9, "b"=>200, "c"=>4, "d"=>42}

Documentation

"Automatic" vs "Automatic (Delayed start)"

In short, services set to Automatic will start during the boot process, while services set to start as Delayed will start shortly after boot.

Starting your service Delayed improves the boot performance of your server and has security benefits which are outlined in the article Adriano linked to in the comments.

Update: "shortly after boot" is actually 2 minutes after the last "automatic" service has started, by default. This can be configured by a registry key, according to Windows Internals and other sources (3,4).

The registry keys of interest (At least in some versions of windows) are:

  • HKLM\SYSTEM\CurrentControlSet\services\<service name>\DelayedAutostart will have the value 1 if delayed, 0 if not.
  • HKLM\SYSTEM\CurrentControlSet\services\AutoStartDelay or HKLM\SYSTEM\CurrentControlSet\Control\AutoStartDelay (on Windows 10): decimal number of seconds to wait, may need to create this one. Applies globally to all Delayed services.

invalid conversion from 'const char*' to 'char*'

string::c.str() returns a string of type const char * as seen here

A quick fix: try casting printfunc(num,addr,(char *)data.str().c_str());

While the above may work, it is undefined behaviour, and unsafe.

Here's a nicer solution using templates:

char * my_argument = const_cast<char*> ( ...c_str() );

SQL Server - boolean literal?

SQL Server doesn't have a boolean data type. As @Mikael has indicated, the closest approximation is the bit. But that is a numeric type, not a boolean type. In addition, it only supports 2 values - 0 or 1 (and one non-value, NULL).

SQL (standard SQL, as well as T-SQL dialect) describes a Three valued logic. The boolean type for SQL should support 3 values - TRUE, FALSE and UNKNOWN (and also, the non-value NULL). So bit isn't actually a good match here.

Given that SQL Server has no support for the data type, we should not expect to be able to write literals of that "type".

how to read a text file using scanner in Java?

Just another thing... Instead of System.out.println("Error Message Here"), use System.err.println("Error Message Here"). This will allow you to distinguish the differences between errors and normal code functioning by displaying the errors(i.e. everything inside System.err.println()) in red.

NOTE: It also works when used with System.err.print("Error Message Here")

iPhone - Get Position of UIView within entire UIWindow

For me this code worked best:

private func getCoordinate(_ view: UIView) -> CGPoint {
    var x = view.frame.origin.x
    var y = view.frame.origin.y
    var oldView = view

    while let superView = oldView.superview {
        x += superView.frame.origin.x
        y += superView.frame.origin.y
        if superView.next is UIViewController {
            break //superView is the rootView of a UIViewController
        }
        oldView = superView
    }

    return CGPoint(x: x, y: y)
}

How to write to a file without overwriting current contents?

Instead of "w" use "a" (append) mode with open function:

with open("games.txt", "a") as text_file:

Formula to convert date to number

If you change the format of the cells to General then this will show the date value of a cell as behind the scenes Excel saves a date as the number of days since 01/01/1900

Screenprint 1

Screenprint 2

If your date is text and you need to convert it then DATEVALUE will do this:

Datevalue function

jQuery: load txt file and insert into div

 <script type="text/javascript">     
   $("#textFileID").html("Loading...").load("URL TEXT");
 </script>  

 <div id="textFileID"></div>

MySQL export into outfile : CSV escaping chars

Without actually seeing your output file for confirmation, my guess is that you've got to get rid of the FIELDS ESCAPED BY value.

MySQL's FIELDS ESCAPED BY is probably behaving in two ways that you were not counting on: (1) it is only meant to be one character, so in your case it is probably equal to just one quotation mark; (2) it is used to precede each character that MySQL thinks needs escaping, including the FIELDS TERMINATED BY and LINES TERMINATED BY values. This makes sense to most of the computing world, but it isn't the way Excel does escaping.

I think your double REPLACE is working, and that you are successfully replacing literal newlines with spaces (two spaces in the case of Windows-style newlines). But if you have any commas in your data (literals, not field separators), these are being preceded by quotation marks, which Excel treats much differently than MySQL. If that's the case, then the erroneous newlines that are tripping up Excel are actually newlines that MySQL had intended as line terminators.

Set a cookie to never expire

Never and forever are two words that I avoid using due to the unpredictability of life.

The latest time since 1 January 1970 that can be stored using a signed 32-bit integer is 03:14:07 on Tuesday, 19 January 2038 (231-1 = 2,147,483,647 seconds after 1 January 1970). This limitation is known as the Year 2038 problem

setCookie("name", "value", strtotime("2038-01-19 03:14:07"));

ORA-01950: no privileges on tablespace 'USERS'

You cannot insert data because you have a quota of 0 on the tablespace. To fix this, run

ALTER USER <user> quota unlimited on <tablespace name>;

or

ALTER USER <user> quota 100M on <tablespace name>;

as a DBA user (depending on how much space you need / want to grant).

How do you add a Dictionary of items into another Dictionary

Swift 2.2

func + <K,V>(left: [K : V], right: [K : V]) -> [K : V] {
    var result = [K:V]()

    for (key,value) in left {
        result[key] = value
    }

    for (key,value) in right {
        result[key] = value
    }
    return result
}

System.Data.OracleClient requires Oracle client software version 8.1.7

Why not use this: dotConnect for Oracle (formerly known as OraDirect .NET)?

It can be configured to not require an Oracle Client at all.

We have been using this in both Windows Services and ASP.NET Web Services and it works like a charm.

Import-CSV and Foreach

$IP_Array = (Get-Content test2.csv)[0].split(",")
foreach ( $IP in $IP_Array){
    $IP
}

Get-content Filename returns an array of strings for each line.

On the first string only, I split it based on ",". Dumping it into $IP_Array.

$IP_Array = (Get-Content test2.csv)[0].split(",")
foreach ( $IP in $IP_Array){
  if ($IP -eq "2.2.2.2") {
    Write-Host "Found $IP"
  }
}

Key existence check in HashMap

if(map.get(key) != null || (map.get(key) == null && map.containsKey(key)))

ASP.net Repeater get current index, pointer, or counter

To display the item number on the repeater you can use the Container.ItemIndex property.

<asp:repeater id="rptRepeater" runat="server">
    <itemtemplate>
        Item <%# Container.ItemIndex + 1 %>| <%# Eval("Column1") %>
    </itemtemplate>
    <separatortemplate>
        <br />
    </separatortemplate>
</asp:repeater>

How to pass a list from Python, by Jinja2 to JavaScript

You can do this with Jinja's tojson filter, which

Dumps a structure to JSON so that it’s safe to use in <script> tags [and] in any place in HTML with the notable exception of double quoted attributes.

For example, in your Python, write:

some_template.render(list_of_items=list_of_items)

... or, in the context of a Flask endpoint:

return render_template('your_template.html', list_of_items=list_of_items)

Then in your template, write this:

{% for item in list_of_items %}
<span onclick='somefunction({{item | tojson}})'>{{item}}</span><br>
{% endfor %}

(Note that the onclick attribute is single-quoted. This is necessary since |tojson escapes ' characters but not " characters in its output, meaning that it can be safely used in single-quoted HTML attributes but not double-quoted ones.)

Or, to use list_of_items in an inline script instead of an HTML attribute, write this:

<script>
const jsArrayOfItems = {{list_of_items | tojson}};
// ... do something with jsArrayOfItems in JavaScript ...
</script>

DON'T use json.dumps to JSON-encode variables in your Python code and pass the resulting JSON text to your template. This will produce incorrect output for some string values, and will expose you to XSS if you're trying to encode user-provided values. This is because Python's built-in json.dumps doesn't escape characters like < and > (which need escaping to safely template values into inline <script>s, as noted at https://html.spec.whatwg.org/multipage/scripting.html#restrictions-for-contents-of-script-elements) or single quotes (which need escaping to safely template values into single-quoted HTML attributes).

If you're using Flask, note that Flask injects a custom tojson filter instead of using Jinja's version. However, everything written above still applies. The two versions behave almost identically; Flask's just allows for some app-specific configuration that isn't available in Jinja's version.

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

In Python we can use the __str__() method.

We can override it in our class like this:

class User: 

    firstName = ''
    lastName = ''
    ...

    def __str__(self):
        return self.firstName + " " + self.lastName

and when running

print(user)

it will call the function __str__(self) and print the firstName and lastName

How to reset all checkboxes using jQuery or pure JS?

 $(":checkbox:checked").each(function () {

 this.click(); 
});

to unchecked checked box, turn your logic around to do opposite

Call to undefined function curl_init().?

You have to enable curl with php.

Here is the instructions for same

Adding Table rows Dynamically in Android

Create an init() function and point the table layout. Then create the needed rows and columns.

   public void init() {
            TableLayout stk = (TableLayout) findViewById(R.id.table_main);
            TableRow tbrow0 = new TableRow(this);
            TextView tv0 = new TextView(this);
            tv0.setText(" Sl.No ");
            tv0.setTextColor(Color.WHITE);
            tbrow0.addView(tv0);
            TextView tv1 = new TextView(this);
            tv1.setText(" Product ");
            tv1.setTextColor(Color.WHITE);
            tbrow0.addView(tv1);
            TextView tv2 = new TextView(this);
            tv2.setText(" Unit Price ");
            tv2.setTextColor(Color.WHITE);
            tbrow0.addView(tv2);
            TextView tv3 = new TextView(this);
            tv3.setText(" Stock Remaining ");
            tv3.setTextColor(Color.WHITE);
            tbrow0.addView(tv3);
            stk.addView(tbrow0);
            for (int i = 0; i < 25; i++) {
                TableRow tbrow = new TableRow(this);
                TextView t1v = new TextView(this);
                t1v.setText("" + i);
                t1v.setTextColor(Color.WHITE);
                t1v.setGravity(Gravity.CENTER);
                tbrow.addView(t1v);
                TextView t2v = new TextView(this);
                t2v.setText("Product " + i);
                t2v.setTextColor(Color.WHITE);
                t2v.setGravity(Gravity.CENTER);
                tbrow.addView(t2v);
                TextView t3v = new TextView(this);
                t3v.setText("Rs." + i);
                t3v.setTextColor(Color.WHITE);
                t3v.setGravity(Gravity.CENTER);
                tbrow.addView(t3v);
                TextView t4v = new TextView(this);
                t4v.setText("" + i * 15 / 32 * 10);
                t4v.setTextColor(Color.WHITE);
                t4v.setGravity(Gravity.CENTER);
                tbrow.addView(t4v);
                stk.addView(tbrow);
            }

        }

Call init function in your onCreate method:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        init();
    }

Layout file like:

 <ScrollView
        android:id="@+id/scrollView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="#3d455b"
        android:layout_alignParentLeft="true" >

        <HorizontalScrollView
            android:id="@+id/hscrll1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >

            <RelativeLayout
                android:id="@+id/RelativeLayout1"
                android:layout_width="fill_parent"
                android:layout_gravity="center"
                android:layout_height="fill_parent"
                android:orientation="vertical" >

                <TableLayout
                    android:id="@+id/table_main"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_centerHorizontal="true" >
                </TableLayout>
            </RelativeLayout>
        </HorizontalScrollView>
    </ScrollView>

Will look like:

enter image description here

How to UPSERT (MERGE, INSERT ... ON DUPLICATE UPDATE) in PostgreSQL?

WITH UPD AS (UPDATE TEST_TABLE SET SOME_DATA = 'Joe' WHERE ID = 2 
RETURNING ID),
INS AS (SELECT '2', 'Joe' WHERE NOT EXISTS (SELECT * FROM UPD))
INSERT INTO TEST_TABLE(ID, SOME_DATA) SELECT * FROM INS

Tested on Postgresql 9.3

Javascript replace all "%20" with a space

If you need to remove white spaces at the end then here is a solution: https://www.geeksforgeeks.org/urlify-given-string-replace-spaces/

_x000D_
_x000D_
const stringQ1 = (string)=>{_x000D_
  //remove white space at the end _x000D_
  const arrString = string.split("")_x000D_
  for(let i = arrString.length -1 ; i>=0 ; i--){_x000D_
    let char = arrString[i];_x000D_
    _x000D_
    if(char.indexOf(" ") >=0){_x000D_
     arrString.splice(i,1)_x000D_
    }else{_x000D_
      break;_x000D_
    }_x000D_
  }_x000D_
_x000D_
  let start =0;_x000D_
  let end = arrString.length -1;_x000D_
  _x000D_
_x000D_
  //add %20_x000D_
  while(start < end){_x000D_
    if(arrString[start].indexOf(' ') >=0){_x000D_
      arrString[start] ="%20"_x000D_
      _x000D_
    }_x000D_
    _x000D_
    start++;_x000D_
  }_x000D_
  _x000D_
  return arrString.join('');_x000D_
}_x000D_
_x000D_
console.log(stringQ1("Mr John Smith   "))
_x000D_
_x000D_
_x000D_

n-grams in python, four, five, six grams?

I'm surprised that this hasn't shown up yet:

In [34]: sentence = "I really like python, it's pretty awesome.".split()

In [35]: N = 4

In [36]: grams = [sentence[i:i+N] for i in xrange(len(sentence)-N+1)]

In [37]: for gram in grams: print gram
['I', 'really', 'like', 'python,']
['really', 'like', 'python,', "it's"]
['like', 'python,', "it's", 'pretty']
['python,', "it's", 'pretty', 'awesome.']

How to stop VBA code running?

Add another button called "CancelButton" that sets a flag, and then check for that flag.

If you have long loops in the "stuff" then check for it there too and exit if it's set. Use DoEvents inside long loops to ensure that the UI works.

Bool Cancel
Private Sub CancelButton_OnClick()
    Cancel=True
End Sub
...
Private Sub SomeVBASub
    Cancel=False
    DoStuff
    If Cancel Then Exit Sub
    DoAnotherStuff
    If Cancel Then Exit Sub
    AndFinallyDothis
End Sub

How do I use NSTimer?

Firstly I'd like to draw your attention to the Cocoa/CF documentation (which is always a great first port of call). The Apple docs have a section at the top of each reference article called "Companion Guides", which lists guides for the topic being documented (if any exist). For example, with NSTimer, the documentation lists two companion guides:

For your situation, the Timer Programming Topics article is likely to be the most useful, whilst threading topics are related but not the most directly related to the class being documented. If you take a look at the Timer Programming Topics article, it's divided into two parts:

  • Timers
  • Using Timers

For articles that take this format, there is often an overview of the class and what it's used for, and then some sample code on how to use it, in this case in the "Using Timers" section. There are sections on "Creating and Scheduling a Timer", "Stopping a Timer" and "Memory Management". From the article, creating a scheduled, non-repeating timer can be done something like this:

[NSTimer scheduledTimerWithTimeInterval:2.0
    target:self
    selector:@selector(targetMethod:)
    userInfo:nil
    repeats:NO];

This will create a timer that is fired after 2.0 seconds and calls targetMethod: on self with one argument, which is a pointer to the NSTimer instance.

If you then want to look in more detail at the method you can refer back to the docs for more information, but there is explanation around the code too.

If you want to stop a timer that is one which repeats, (or stop a non-repeating timer before it fires) then you need to keep a pointer to the NSTimer instance that was created; often this will need to be an instance variable so that you can refer to it in another method. You can then call invalidate on the NSTimer instance:

[myTimer invalidate];
myTimer = nil;

It's also good practice to nil out the instance variable (for example if your method that invalidates the timer is called more than once and the instance variable hasn't been set to nil and the NSTimer instance has been deallocated, it will throw an exception).

Note also the point on Memory Management at the bottom of the article:

Because the run loop maintains the timer, from the perspective of memory management there's typically no need to keep a reference to a timer after you’ve scheduled it. Since the timer is passed as an argument when you specify its method as a selector, you can invalidate a repeating timer when appropriate within that method. In many situations, however, you also want the option of invalidating the timer—perhaps even before it starts. In this case, you do need to keep a reference to the timer, so that you can send it an invalidate message whenever appropriate. If you create an unscheduled timer (see “Unscheduled Timers”), then you must maintain a strong reference to the timer (in a reference-counted environment, you retain it) so that it is not deallocated before you use it.

Bootstrap 3 Styled Select dropdown looks ugly in Firefox on OS X

Building on the excellent answers by rafx and Sina, here is a snippet that only targets Firefox and replaces the default button with a down-caret copied from Bootstrap's icon theme.

Before:

default select

After:

styled select

@-moz-document url-prefix() {
  select.form-control {
    padding-right: 25px;
    background-image: url("data:image/svg+xml,\
      <svg version='1.1' xmlns='http://www.w3.org/2000/svg' width='14px'\
           height='14px' viewBox='0 0 1200 1000' fill='rgb(51,51,51)'>\
        <path d='M1100 411l-198 -199l-353 353l-353 -353l-197 199l551 551z'/>\
      </svg>");
    background-repeat: no-repeat;
    background-position: calc(100% - 7px) 50%;
    -moz-appearance: none;
    appearance: none;
  }
}

(The inline SVG has backslashes and newlines for readability. Remove them if they cause trouble in your asset pipeline.)

Here is the JSFiddle

PHP foreach loop through multidimensional array

<?php
$first = reset($arr_nav); // Get the first element
$last  = end($arr_nav);   // Get the last element
// Ensure that we have a first element and that it's an array
if(is_array($first)) { 
   $first['class'] = 'first';
}
// Ensure we have a last element and that it differs from the first
if(is_array($last) && $last !== $first) {
   $last['class'] = 'last';
}

Now you could just echo the class inside you html-generator. Would probably need some kind of check to ensure that the class is set, or provide a default empty class to the array.

What is the return value of os.system() in Python?

os.system('command') returns a 16 bit number, which first 8 bits from left(lsb) talks about signal used by os to close the command, Next 8 bits talks about return code of command.

00000000    00000000
exit code   signal num

Example 1 - command exit with code 1

os.system('command') #it returns 256
256 in 16 bits -  00000001 00000000
Exit code is 00000001 which means 1

Example 2 - command exit with code 3

os.system('command') # it returns 768
768 in 16 bits  - 00000011 00000000
Exit code is 00000011 which means 3

Now try with signal - Example 3 - Write a program which sleep for long time use it as command in os.system() and then kill it by kill -15 or kill -9

os.system('command') #it returns signal num by which it is killed
15 in bits - 00000000 00001111
Signal num is 00001111 which means 15

You can have a python program as command = 'python command.py'

import sys
sys.exit(n)  # here n would be exit code

In case of c or c++ program you can use return from main() or exit(n) from any function #

Note - This is applicable on unix

On Unix, the return value is the exit status of the process encoded in the format specified for wait(). Note that POSIX does not specify the meaning of the return value of the C system() function, so the return value of the Python function is system-dependent.

os.wait()

Wait for completion of a child process, and return a tuple containing its pid and exit status indication: a 16-bit number, whose low byte is the signal number that killed the process, and whose high byte is the exit status (if the signal number is zero); the high bit of the low byte is set if a core file was produced.

Availability: Unix

.

Error: Could not find or load main class in intelliJ IDE

If the class which has the main method is extending/implementing another class/interface then it will not find the main class. Change the signature and it should work.

I had the same problem tried almost every answer from this thread non of them worked. Then this worked for me.

How to save select query results within temporary table?

You can also do the following:

CREATE TABLE #TEMPTABLE
(
    Column1 type1,
    Column2 type2,
    Column3 type3
)

INSERT INTO #TEMPTABLE
SELECT ...

SELECT *
FROM #TEMPTABLE ...

DROP TABLE #TEMPTABLE

Difference of two date time in sql server

Ok we all know the answer involves DATEDIFF(). But that gives you only half the result you may be after. What if you want to get the results in human-readable format, in terms of Minutes and Seconds between two DATETIME values?

The CONVERT(), DATEADD() and of course DATEDIFF() functions are perfect for a more easily readable result that your clients can use, instead of a number.

i.e.

CONVERT(varchar(5), DATEADD(minute, DATEDIFF(MINUTE, date1, date2), 0), 114) 

This will give you something like:

HH:MM

If you want more precision, just increase the VARCHAR().

CONVERT(varchar(12), DATEADD(minute, DATEDIFF(MINUTE, date1, date2), 0), 114) 

HH:MM.SS.MS

Splitting comma separated string in a PL/SQL stored proc

I use apex_util.string_to_table to parse strings, but you can use a different parser if you wish. Then you can insert the data as in this example:

declare
  myString varchar2(2000) :='0.75, 0.64, 0.56, 0.45';
  myAmount varchar2(2000) :='0.25, 0.5, 0.65, 0.8';
  v_array1 apex_application_global.vc_arr2;
  v_array2 apex_application_global.vc_arr2;
begin

  v_array1 := apex_util.string_to_table(myString, ', ');
  v_array2 := apex_util.string_to_table(myAmount, ', ');

  forall i in 1..v_array1.count
     insert into mytable (a, b) values (v_array1(i), v_array2(i));
end;

Apex_util is available from Oracle 10G onwards. Prior to this it was called htmldb_util and was not installed by default. If you can't use that you could use the string parser I wrote many years ago and posted here.

Android Studio - Emulator - eglSurfaceAttrib not implemented

I've found the same thing, but only on emulators that have the Use Host GPU setting ticked. Try turning that off, you'll no longer see those warnings (and the emulator will run horribly, horribly slowly..)

In my experience those warnings are harmless. Notice that the "error" is EGL_SUCCESS, which would seem to indicate no error at all!

Is a DIV inside a TD a bad idea?

A table-cell can legitimately contain block-level elements so it's not, inherently, a faux-pas. Browser implentation, of course, leaves this a speculative-theoretical position. It may cause layout problems and bugs.

Though as tables were used for layout -and sometimes still are- I imagine that most browsers will render the content properly. Even IE.

Laravel Eloquent get results grouped by days

To group data according to DATE instead of DATETIME, you can use CAST function.

$visitorTraffic = PageView::select('id', 'title', 'created_at')
->get()
->groupBy(DB::raw('CAST(created_at AS DATE)'));

Redis: Show database size/size for keys

So my solution to my own problem: After playing around with redis-cli a bit longer I found out that DEBUG OBJECT <key> reveals something like the serializedlength of key, which was in fact something I was looking for...

For a whole database you need to aggregate all values for KEYS * which shouldn't be too difficult with a scripting language of your choice...

The bad thing is that redis.io doesn't really have a lot of information about DEBUG OBJECT.

How do I properly force a Git push?

I would really recommend to:

  • push only to the main repo

  • make sure that main repo is a bare repo, in order to never have any problem with the main repo working tree being not in sync with its .git base. See "How to push a local git repository to another computer?"

  • If you do have to make modification in the main (bare) repo, clone it (on the main server), do your modification and push back to it

In other words, keep a bare repo accessible both from the main server and the local computer, in order to have a single upstream repo from/to which to pull/pull.

How to scan a folder in Java?

In JDK7, "more NIO features" should have methods to apply the visitor pattern over a file tree or just the immediate contents of a directory - no need to find all the files in a potentially huge directory before iterating over them.

How to suppress binary file matching results in grep

There are three options, that you can use. -I is to exclude binary files in grep. Other are for line numbers and file names.

grep -I -n -H 


-I -- process a binary file as if it did not contain matching data; 
-n -- prefix each line of output with the 1-based line number within its input file
-H -- print the file name for each match

So this might be a way to run grep:

grep -InH your-word *

How to search for string in an array

more simple Function whichs works on Apple OS too:

Function isInArray(ByVal stringToBeFound As String, ByVal arr As Variant) As Boolean
Dim element
For Each element In arr
    If element = stringToBeFound Then
        isInArray = True
        Exit Function
    End If
Next element
End Function

Java: unparseable date exception

From Oracle docs, Date.toString() method convert Date object to a String of the specific form - do not use toString method on Date object. Try to use:

String stringDate = new SimpleDateFormat(YOUR_STRING_PATTERN).format(yourDateObject);

Next step is parse stringDate to Date:

Date date = new SimpleDateFormat(OUTPUT_PATTERN).parse(stringDate);

Note that, parse method throws ParseException

How do I remove  from the beginning of a file?

I don't know PHP, so I don't know if this is possible, but the best solution would be to read the file as UTF-8 rather than some other encoding. The BOM is actually a ZERO WIDTH NO BREAK SPACE. This is whitespace, so if the file were being read in the correct encoding (UTF-8), then the BOM would be interpreted as whitespace and it would be ignored in the resulting CSS file.

Also, another advantage of reading the file in the correct encoding is that you don't have to worry about characters being misinterpreted. Your editor is telling you that the code page you want to save it in won't do all the characters that you need. If PHP is then reading the file in the incorrect encoding, then it is very likely that other characters besides the BOM are being silently misinterpreted. Use UTF-8 everywhere, and these problems disappear.

first-child and last-child with IE8

If you want to carry on using CSS3 selectors but need to support older browsers I would suggest using a polyfill such as Selectivizr.js

filter items in a python dictionary where keys contain a specific string

You can use the built-in filter function to filter dictionaries, lists, etc. based on specific conditions.

filtered_dict = dict(filter(lambda item: filter_str in item[0], d.items()))

The advantage is that you can use it for different data structures.

How to get height of entire document with JavaScript?

You can even use this:

var B = document.body,
    H = document.documentElement,
    height

if (typeof document.height !== 'undefined') {
    height = document.height // For webkit browsers
} else {
    height = Math.max( B.scrollHeight, B.offsetHeight,H.clientHeight, H.scrollHeight, H.offsetHeight );
}

or in a more jQuery way (since as you said jQuery doesn't lie) :)

Math.max($(document).height(), $(window).height())

What is the use of ObservableCollection in .net?

Explanation without Code

For those wanting an answer without any code behind it (boom-tish) with a story (to help you remember):

Normal Collections - No Notifications

Every now and then I go to NYC and my wife asks me to buy stuff. So I take a shopping list with me. The list has a lot of things on there like:

  1. Louis Vuitton handbag ($5000)
  2. Clive Christian’s Imperial Majesty Perfume ($215,000 )
  3. Gucci Sunglasses ($2000)

hahaha well I"m not buying that stuff. So I cross them off and remove them from the list and I add instead:

  1. 12 dozen Titleist golf balls.
  2. 12 lb bowling ball.

So I usually come home without the goods and she's never pleased. The thing is that she doesn't know about what i take off the list and what I add onto it; she gets no notifications.

The ObservableCollection - notifications when changes made

Now, whenever I remove something from the list: she get's a notification on her phone (i.e. sms / email etc)!

The observable collection works just the same way. If you add or remove something to or from it: someone is notified. And when they are notified, well then they call you and you'll get a ear-full. Of course the consequences are customisable via the event handler.

That sums it all up!

How do I integrate Ajax with Django applications?

I have tried to use AjaxableResponseMixin in my project, but had ended up with the following error message:

ImproperlyConfigured: No URL to redirect to. Either provide a url or define a get_absolute_url method on the Model.

That is because the CreateView will return a redirect response instead of returning a HttpResponse when you to send JSON request to the browser. So I have made some changes to the AjaxableResponseMixin. If the request is an ajax request, it will not call the super.form_valid method, just call the form.save() directly.

from django.http import JsonResponse
from django import forms
from django.db import models

class AjaxableResponseMixin(object):
    success_return_code = 1
    error_return_code = 0
    """
    Mixin to add AJAX support to a form.
    Must be used with an object-based FormView (e.g. CreateView)
    """
    def form_invalid(self, form):
        response = super(AjaxableResponseMixin, self).form_invalid(form)
        if self.request.is_ajax():
            form.errors.update({'result': self.error_return_code})
            return JsonResponse(form.errors, status=400)
        else:
            return response

    def form_valid(self, form):
        # We make sure to call the parent's form_valid() method because
        # it might do some processing (in the case of CreateView, it will
        # call form.save() for example).
        if self.request.is_ajax():
            self.object = form.save()
            data = {
                'result': self.success_return_code
            }
            return JsonResponse(data)
        else:
            response = super(AjaxableResponseMixin, self).form_valid(form)
            return response

class Product(models.Model):
    name = models.CharField('product name', max_length=255)

class ProductAddForm(forms.ModelForm):
    '''
    Product add form
    '''
    class Meta:
        model = Product
        exclude = ['id']


class PriceUnitAddView(AjaxableResponseMixin, CreateView):
    '''
    Product add view
    '''
    model = Product
    form_class = ProductAddForm

How to get the index of a maximum element in a NumPy array along one axis

There is argmin() and argmax() provided by numpy that returns the index of the min and max of a numpy array respectively.

Say e.g for 1-D array you'll do something like this

_x000D_
_x000D_
import numpy as np

a = np.array([50,1,0,2])

print(a.argmax()) # returns 0
print(a.argmin()) # returns 2
_x000D_
_x000D_
_x000D_

And similarly for multi-dimensional array

_x000D_
_x000D_
import numpy as np

a = np.array([[0,2,3],[4,30,1]])

print(a.argmax()) # returns 4
print(a.argmin()) # returns 0
_x000D_
_x000D_
_x000D_

Note that these will only return the index of the first occurrence.

Why is Dictionary preferred over Hashtable in C#?

Because Dictionary is a generic class ( Dictionary<TKey, TValue> ), so that accessing its content is type-safe (i.e. you do not need to cast from Object, as you do with a Hashtable).

Compare

var customers = new Dictionary<string, Customer>();
...
Customer customer = customers["Ali G"];

to

var customers = new Hashtable();
...
Customer customer = customers["Ali G"] as Customer;

However, Dictionary is implemented as hash table internally, so technically it works the same way.

How do you debug PHP scripts?

Usually I find create a custom log function able to save on file, store debug info, and eventually re-print on a common footer.

You can also override common Exception class, so that this type of debugging is semi-automated.

What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)

This situation happens when the IDE looks for src folder, and it cannot find it in the path. Select the project root (F4 in windows) > Go to Modules on Side Tab > Select Sources > Select appropriate folder with source files in it> Click on the blue sources folder icon (for adding sources) > Click on Green Test Sources folder ( to add Unit test folders).

Simulating Button click in javascript

Or you can use what JQuery alreay made for you:

http://jqueryui.com/datepicker/#icon-trigger

It's what you are trying to achieve isn't it?

Visual Studio 2017 - Git failed with a fatal error

I tried a lot and finally got it working with some modification from what I read in Git - Can't clone remote repository:

  1. Modify Visual Studio 2017 CE installation ? remove Git for windows (installer ? modify ? single components).

  2. Delete everything from C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer\Git.

  3. Modify Visual Studio 2017 CE installation ? add Git for windows (installer ? modify ? single components)

  4. Install Git on windows (32 or 64 bit version), having Git in system path configured.

Maybe point 2 and 3 are not needed; I didn't try.

Now it works OK on my Gogs.

Using isKindOfClass with Swift

Another approach using the new Swift 2 syntax is to use guard and nest it all in one conditional.

guard let touch = object.AnyObject() as? UITouch, let picker = touch.view as? UIPickerView else {
    return //Do Nothing
}
//Do something with picker

Postgres: check if array field contains value?

With ANY operator you can search for only one value.

For example,

select * from mytable where 'Book' = ANY(pub_types);

If you want to search multiple values, you can use @> operator.

For example,

select * from mytable where pub_types @> '{"Journal", "Book"}';

You can specify in which ever order you like.

How do I escape double quotes in attributes in an XML String in T-SQL?

Cannot comment anymore but voted it up and wanted to let folks know that &quot; works very well for the xml config files when forming regex expressions for RegexTransformer in Solr like so: regex=".*img src=&quot;(.*)&quot;.*" using the escaped version instead of double-quotes.

Does List<T> guarantee insertion order?

Here are 4 items, with their index

0  1  2  3
K  C  A  E

You want to move K to between A and E -- you might think position 3. You have be careful about your indexing here, because after the remove, all the indexes get updated.

So you remove item 0 first, leaving

0  1  2
C  A  E

Then you insert at 3

0  1  2  3
C  A  E  K

To get the correct result, you should have used index 2. To make things consistent, you will need to send to (indexToMoveTo-1) if indexToMoveTo > indexToMove, e.g.

bool moveUp = (listInstance.IndexOf(itemToMoveTo) > indexToMove);
listInstance.Remove(itemToMove);
listInstance.Insert(indexToMoveTo, moveUp ? (itemToMoveTo - 1) : itemToMoveTo);

This may be related to your problem. Note my code is untested!

EDIT: Alternatively, you could Sort with a custom comparer (IComparer) if that's applicable to your situation.

How to make a page redirect using JavaScript?

Use:

document.location.href = "http://yoursite.com" + document.getElementById('somefield');

That would get the value of some text field or hidden field, and add it to your site URL to get a new URL (href). You can modify this to suit your needs.

How to load property file from classpath?

If you use the static method and load the properties file from the classpath folder so you can use the below code :

//load a properties file from class path, inside static method
Properties prop = new Properties();
prop.load(Classname.class.getClassLoader().getResourceAsStream("foo.properties"));

How do I convert array of Objects into one Object in JavaScript?

Use lodash!

const obj = _.keyBy(arrayOfObjects, 'keyName')

XSLT equivalent for JSON

As yet another new answer to an old question, I'd suggest a look at DefiantJS. It's not an XSLT equivalent for JSON, it is XSLT for JSON. The "Templating" section of the documentation includes this example:

<!-- Defiant template -->
<script type="defiant/xsl-template">
    <xsl:template name="books_template">
        <xsl:for-each select="//movie">
            <xsl:value-of select="title"/><br/>
        </xsl:for-each>
    </xsl:template>
</script>

<script type="text/javascript">

var data = {
        "movie": [
            {"title": "The Usual Suspects"},
            {"title": "Pulp Fiction"},
            {"title": "Independence Day"}
        ]
    },
    htm = Defiant.render('books_template', data);

console.log(htm);
// The Usual Suspects<br>
// Pulp Fiction<br>
// Independence Day<br>

How to get the response of XMLHttpRequest?

In XMLHttpRequest, using XMLHttpRequest.responseText may raise the exception like below

 Failed to read the \'responseText\' property from \'XMLHttpRequest\': 
 The value is only accessible if the object\'s \'responseType\' is \'\' 
 or \'text\' (was \'arraybuffer\')

Best way to access the response from XHR as follows

function readBody(xhr) {
    var data;
    if (!xhr.responseType || xhr.responseType === "text") {
        data = xhr.responseText;
    } else if (xhr.responseType === "document") {
        data = xhr.responseXML;
    } else {
        data = xhr.response;
    }
    return data;
}

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
    if (xhr.readyState == 4) {
        console.log(readBody(xhr));
    }
}
xhr.open('GET', 'http://www.google.com', true);
xhr.send(null);

Stop a gif animation onload, on mouseover start the activation

I realise this answer is late, but I found a rather simple, elegant, and effective solution to this problem and felt it necessary to post it here.

However one thing I feel I need to make clear is that this doesn't start gif animation on mouseover, pause it on mouseout, and continue it when you mouseover it again. That, unfortunately, is impossible to do with gifs. (It is possible to do with a string of images displayed one after another to look like a gif, but taking apart every frame of your gifs and copying all those urls into a script would be time consuming)

What my solution does is make an image looks like it starts moving on mouseover. You make the first frame of your gif an image and put that image on the webpage then replace the image with the gif on mouseover and it looks like it starts moving. It resets on mouseout.

Just insert this script in the head section of your HTML:

$(document).ready(function()
{
    $("#imgAnimate").hover(
        function()
        {
            $(this).attr("src", "GIF URL HERE");
        },
        function()
        {
            $(this).attr("src", "STATIC IMAGE URL HERE");
        });
});

And put this code in the img tag of the image you want to animate.

id="imgAnimate"

This will load the gif on mouseover, so it will seem like your image starts moving. (This is better than loading the gif onload because then the transition from static image to gif is choppy because the gif will start on a random frame)

for more than one image just recreate the script create a function:

<script type="text/javascript">

var staticGifSuffix = "-static.gif";
var gifSuffix = ".gif";

$(document).ready(function() {

  $(".img-animate").each(function () {

     $(this).hover(
        function()
        {
            var originalSrc = $(this).attr("src");
            $(this).attr("src", originalSrc.replace(staticGifSuffix, gifSuffix));
        },
        function()
        {
            var originalSrc = $(this).attr("src");
            $(this).attr("src", originalSrc.replace(gifSuffix, staticGifSuffix));  
        }
     );

  });

});
</script>

</head>
<body>

<img class="img-animate" src="example-static.gif" >
<img class="img-animate" src="example-static.gif" >
<img class="img-animate" src="example-static.gif" >
<img class="img-animate" src="example-static.gif" >
<img class="img-animate" src="example-static.gif" >

</body>

That code block is a functioning web page (based on the information you have given me) that will display the static images and on hover, load and display the gif's. All you have to do is insert the url's for the static images.

Command to get latest Git commit hash from a branch

In a comment you wrote

i want to show that there is a difference in local and github repo

As already mentioned in another answer, you should do a git fetch origin first. Then, if the remote is ahead of your current branch, you can list all commits between your local branch and the remote with

git log master..origin/master --stat

If your local branch is ahead:

git log origin/master..master --stat

--stat shows a list of changed files as well.

If you want to explicitly list the additions and deletions, use git diff:

git diff master origin/master

Java 8 stream map on entry set

Please make the following part of the Collectors API:

<K, V> Collector<? super Map.Entry<K, V>, ?, Map<K, V>> toMap() {
  return Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue);
}

How do I convert a String to an int in Java?

Use Integer.parseInt() and put it inside a try...catch block to handle any errors just in case a non-numeric character is entered, for example,

private void ConvertToInt(){
    String string = txtString.getText();
    try{
        int integerValue=Integer.parseInt(string);
        System.out.println(integerValue);
    }
    catch(Exception e){
       JOptionPane.showMessageDialog(
         "Error converting string to integer\n" + e.toString,
         "Error",
         JOptionPane.ERROR_MESSAGE);
    }
 }

Change output format for MySQL command line results to CSV

mysql client can detect the output fd, if the fd is S_IFIFO(pipe) then don't output ASCII TABLES, if the fd is character device(S_IFCHR) then output ASCII TABLES.

you can use --table to force output the ASCII TABLES like:

$mysql -t -N -h127.0.0.1 -e "select id from sbtest1 limit 1" | cat
+--------+
| 100024 |
+--------+

-t, --table Output in table format.

What is the effect of extern "C" in C++?

Without conflicting with other good answers, I will add a bit of my example.

What exactly C++ Compiler does: it mangles the names in the compilation process, hence we require telling the compiler to treat C implementation specially.

When we are making C++ classes and adding extern "C", we're telling our C++ compiler that we are using C calling convention.

Reason (we are calling C implementation from C++): either we want to call C function from C++ or calling C++ function from C (C++ classes ... etc do not work in C).

PPT to PNG with transparent background

It can't be done, either manually or progamatically. This is because the color behind every slide master is white. If you set your background to 100% transparent, it will print as white.

The best you could do is design your slide with all the stuff you want, group everything you want to appear in the transparent image and then right-click/save as picture/.PNG (or you could do that with a macro as well). In this way you would retain transparency.

Here's an example of how to export all slides' shapes to seperate PNG files. Note:

  1. This does not get any background shapes on the Slide Master.
  2. Resulting PNGs will not be the same size as each other, depending on where the shapes are located on each slide.
  3. This uses a depreciated function, namely Shape.Export. This means that while the function is still available up to PowerPoint 2010, it may be removed from PowerPoint VBA later.

    Sub PrintShapesToPng()
        Dim ap As Presentation: Set ap = ActivePresentation
        Dim sl As slide
        Dim shGroup As ShapeRange
        For Each sl In ap.Slides
            ActiveWindow.View.GotoSlide (sl.SlideIndex)
            sl.Shapes.SelectAll
            Set shGroup = ActiveWindow.Selection.ShapeRange
            shGroup.Export ap.Path & "\Slide" & sl.SlideIndex & ".png", _
                                ppShapeFormatPNG, , , ppRelativeToSlide
        Next
    End Sub
    

How to display an unordered list in two columns?

The legacy solution in the top answer didn't work for me because I wanted to affect multiple lists on the page and the answer assumes a single list plus it uses a fair bit of global state. In this case I wanted to alter every list inside a <section class="list-content">:

const columns = 2;
$("section.list-content").each(function (index, element) {
    let section = $(element);
    let items = section.find("ul li").detach();
    section.find("ul").detach();
    for (let i = 0; i < columns; i++) {
        section.append("<ul></ul>");
    }
    let lists = section.find("ul");
    for (let i = 0; i < items.length; i++) {
        lists.get(i % columns).append(items[i]);
    }
});

text-align: right; not working for <label>

As stated in other answers, label is an inline element. However, you can apply display: inline-block to the label and then center with text-align.

#name_label {
    display: inline-block;
    width: 90%;
    text-align: right;
}

Why display: inline-block and not display: inline? For the same reason that you can't align label, it's inline.

Why display: inline-block and not display: block? You could use display: block, but it will be on another line. display: inline-block combines the properties of inline and block. It's inline, but you can also give it a width, height, and align it.

phonegap open link in browser

I'm using PhoneGap Build (v3.4.0), with focus on iOS, and I needed to have this entry in my config.xml for PhoneGap to recognize the InAppBrowser plug-in.

<gap:plugin name="org.apache.cordova.inappbrowser" />

After that, using window.open(url, target) should work as expected, as documented here.

Retrieving a Foreign Key value with django-rest-framework serializers

Another thing you can do is to:

  • create a property in your Item model that returns the category name and
  • expose it as a ReadOnlyField.

Your model would look like this.

class Item(models.Model):
    name = models.CharField(max_length=100)
    category = models.ForeignKey(Category, related_name='items')

    def __unicode__(self):
        return self.name

    @property
    def category_name(self):
        return self.category.name

Your serializer would look like this. Note that the serializer will automatically get the value of the category_name model property by naming the field with the same name.

class ItemSerializer(serializers.ModelSerializer):
    category_name = serializers.ReadOnlyField()

    class Meta:
        model = Item

Check if any type of files exist in a directory using BATCH script

To check if a folder contains at least one file

>nul 2>nul dir /a-d "folderName\*" && (echo Files exist) || (echo No file found)

To check if a folder or any of its descendents contain at least one file

>nul 2>nul dir /a-d /s "folderName\*" && (echo Files exist) || (echo No file found)

To check if a folder contains at least one file or folder.
Note addition of /a option to enable finding of hidden and system files/folders.

dir /b /a "folderName\*" | >nul findstr "^" && (echo Files and/or Folders exist) || (echo No File or Folder found)

To check if a folder contains at least one folder

dir /b /ad "folderName\*" | >nul findstr "^" && (echo Folders exist) || (echo No folder found)

How to download and save a file from Internet using Java?

Downloading a file requires you to read it, either way you will have to go through the file in some way. Instead of line by line, you can just read it by bytes from the stream:

BufferedInputStream in = new BufferedInputStream(new URL("http://www.website.com/information.asp").openStream())
    byte data[] = new byte[1024];
    int count;
    while((count = in.read(data,0,1024)) != -1)
    {
        out.write(data, 0, count);
    }

How to format x-axis time scale values in Chart.js v2

You could format the dates before you add them to your array. That is how I did. I used AngularJS

//convert the date to a standard format

var dt = new Date(date);

//take only the date and month and push them to your label array

$rootScope.charts.mainChart.labels.push(dt.getDate() + "-" + (dt.getMonth() + 1));

Use this array in your chart presentation

HttpGet with HTTPS : SSLPeerUnverifiedException

Note: Do not do this in production code, use http instead, or the actual self signed public key as suggested above.

On HttpClient 4.xx:

import static org.junit.Assert.assertEquals;

import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.junit.Test;

public class HttpClientTrustingAllCertsTest {

    @Test
    public void shouldAcceptUnsafeCerts() throws Exception {
        DefaultHttpClient httpclient = httpClientTrustingAllSSLCerts();
        HttpGet httpGet = new HttpGet("https://host_with_self_signed_cert");
        HttpResponse response = httpclient.execute( httpGet );
        assertEquals("HTTP/1.1 200 OK", response.getStatusLine().toString());
    }

    private DefaultHttpClient httpClientTrustingAllSSLCerts() throws NoSuchAlgorithmException, KeyManagementException {
        DefaultHttpClient httpclient = new DefaultHttpClient();

        SSLContext sc = SSLContext.getInstance("SSL");
        sc.init(null, getTrustingManager(), new java.security.SecureRandom());

        SSLSocketFactory socketFactory = new SSLSocketFactory(sc);
        Scheme sch = new Scheme("https", 443, socketFactory);
        httpclient.getConnectionManager().getSchemeRegistry().register(sch);
        return httpclient;
    }

    private TrustManager[] getTrustingManager() {
        TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {
            @Override
            public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                return null;
            }

            @Override
            public void checkClientTrusted(X509Certificate[] certs, String authType) {
                // Do nothing
            }

            @Override
            public void checkServerTrusted(X509Certificate[] certs, String authType) {
                // Do nothing
            }

        } };
        return trustAllCerts;
    }
}

Row names & column names in R

Just to expand a little on Dirk's example:

It helps to think of a data frame as a list with equal length vectors. That's probably why names works with a data frame but not a matrix.

The other useful function is dimnames which returns the names for every dimension. You will notice that the rownames function actually just returns the first element from dimnames.

Regarding rownames and row.names: I can't tell the difference, although rownames uses dimnames while row.names was written outside of R. They both also seem to work with higher dimensional arrays:

>a <- array(1:5, 1:4)
> a[1,,,]
> rownames(a) <- "a"
> row.names(a)
[1] "a"
> a
, , 1, 1    
  [,1] [,2]
a    1    2

> dimnames(a)
[[1]]
[1] "a"

[[2]]
NULL

[[3]]
NULL

[[4]]
NULL

Laravel Eloquent - Get one Row

Simply use this:

$user = User::whereEmail($email)->first();

What's in an Eclipse .classpath/.project file?

Eclipse is a runtime environment for plugins. Virtually everything you see in Eclipse is the result of plugins installed on Eclipse, rather than Eclipse itself.

The .project file is maintained by the core Eclipse platform, and its goal is to describe the project from a generic, plugin-independent Eclipse view. What's the project's name? what other projects in the workspace does it refer to? What are the builders that are used in order to build the project? (remember, the concept of "build" doesn't pertain specifically to Java projects, but also to other types of projects)

The .classpath file is maintained by Eclipse's JDT feature (feature = set of plugins). JDT holds multiple such "meta" files in the project (see the .settings directory inside the project); the .classpath file is just one of them. Specifically, the .classpath file contains information that the JDT feature needs in order to properly compile the project: the project's source folders (that is, what to compile); the output folders (where to compile to); and classpath entries (such as other projects in the workspace, arbitrary JAR files on the file system, and so forth).

Blindly copying such files from one machine to another may be risky. For example, if arbitrary JAR files are placed on the classpath (that is, JAR files that are located outside the workspace and are referred-to by absolute path naming), the .classpath file is rendered non-portable and must be modified in order to be portable. There are certain best practices that can be followed to guarantee .classpath file portability.

How to add ID property to Html.BeginForm() in asp.net mvc?

This should get the id added.

ASP.NET MVC 5 and lower:

<% using (Html.BeginForm(null, null, FormMethod.Post, new { id = "signupform" }))
   { } %>

ASP.NET Core: You can use tag helpers in forms to avoid the odd syntax for setting the id.

<form asp-controller="Account" asp-action="Register" method="post" id="signupform" role="form"></form>

Evaluating a mathematical expression in a string

Okay, so the problem with eval is that it can escape its sandbox too easily, even if you get rid of __builtins__. All the methods for escaping the sandbox come down to using getattr or object.__getattribute__ (via the . operator) to obtain a reference to some dangerous object via some allowed object (''.__class__.__bases__[0].__subclasses__ or similar). getattr is eliminated by setting __builtins__ to None. object.__getattribute__ is the difficult one, since it cannot simply be removed, both because object is immutable and because removing it would break everything. However, __getattribute__ is only accessible via the . operator, so purging that from your input is sufficient to ensure eval cannot escape its sandbox.
In processing formulas, the only valid use of a decimal is when it is preceded or followed by [0-9], so we just remove all other instances of ..

import re
inp = re.sub(r"\.(?![0-9])","", inp)
val = eval(inp, {'__builtins__':None})

Note that while python normally treats 1 + 1. as 1 + 1.0, this will remove the trailing . and leave you with 1 + 1. You could add ),, and EOF to the list of things allowed to follow ., but why bother?

What does "collect2: error: ld returned 1 exit status" mean?

Include: #include<stdlib.h>

and use System("cls") instead of clrscr()

What's the difference between git clone --mirror and git clone --bare

My tests with git-2.0.0 today indicate that the --mirror option does not copy hooks, the config file, the description file, the info/exclude file, and at least in my test case a few refs (which I don't understand.) I would not call it a "functionally identical copy, interchangeable with the original."

-bash-3.2$ git --version
git version 2.0.0
-bash-3.2$ git clone --mirror /git/hooks
Cloning into bare repository 'hooks.git'...
done.

-bash-3.2$ diff --brief -r /git/hooks.git hooks.git
Files /git/hooks.git/config and hooks.git/config differ
Files /git/hooks.git/description and hooks.git/description differ
...
Only in hooks.git/hooks: applypatch-msg.sample
...
Only in /git/hooks.git/hooks: post-receive
...
Files /git/hooks.git/info/exclude and hooks.git/info/exclude differ
...
Files /git/hooks.git/packed-refs and hooks.git/packed-refs differ
Only in /git/hooks.git/refs/heads: fake_branch
Only in /git/hooks.git/refs/heads: master
Only in /git/hooks.git/refs: meta

Understanding the Gemfile.lock file

It seems no clear document talking on the Gemfile.lock format. Maybe it's because Gemfile.lock is just used by bundle internally.

However, since Gemfile.lock is a snapshot of Gemfile, which means all its information should come from Gemfile (or from default value if not specified in Gemfile).

For GEM, it lists all the dependencies you introduce directly or indirectly in the Gemfile. remote under GEM tells where to get the gems, which is specified by source in Gemfile.

If a gem is not fetch from remote, PATH tells the location to find it. PATH's info comes from path in Gemfile when you declare a dependency.

And PLATFORM is from here.

For DEPENDENCIES, it's the snapshot of dependencies resolved by bundle.

How to start a background process in Python?

I found this here:

On windows (win xp), the parent process will not finish until the longtask.py has finished its work. It is not what you want in CGI-script. The problem is not specific to Python, in PHP community the problems are the same.

The solution is to pass DETACHED_PROCESS Process Creation Flag to the underlying CreateProcess function in win API. If you happen to have installed pywin32 you can import the flag from the win32process module, otherwise you should define it yourself:

DETACHED_PROCESS = 0x00000008

pid = subprocess.Popen([sys.executable, "longtask.py"],
                       creationflags=DETACHED_PROCESS).pid

Swift apply .uppercaseString to only the first letter of a string

In Swift 3.0 (this is a little bit faster and safer than the accepted answer) :

extension String {
    func firstCharacterUpperCase() -> String {
        if let firstCharacter = characters.first {
            return replacingCharacters(in: startIndex..<index(after: startIndex), with: String(firstCharacter).uppercased())
        }
        return ""
    }
}

nameOfString.capitalized won't work, it will capitalize every words in the sentence

How to register ASP.NET 2.0 to web server(IIS7)?

If anyone like me is still unable to register ASP.NET with IIS.

You just need to run these three commands one by one in command prompt

cd c:\windows\Microsoft.Net\Framework\v2.0.50727

after that, Run

aspnet_regiis.exe -i -enable

and Finally Reset IIS

iisreset

Hope it helps the person in need... cheers!

How to correctly get image from 'Resources' folder in NetBeans

For me it worked like I had images in icons folder under src and I wrote below code.

new ImageIcon(getClass().getResource("/icons/rsz_measurment_01.png"));

How to force table cell <td> content to wrap?

If you want fix the column you should set width. For example:

<td style="width:100px;">some data</td>

Gradle task - pass arguments to Java application

If you want to use the same set of arguments all the time, the following is all you need.

run {
    args = ["--myarg1", "--myarg2"]
}

Newline in string attribute

May be you can use the attribute xml:space="preserve" for preserving whitespace in the source XAML

<TextBlock xml:space="preserve">
Stuff on line 1
Stuff on line 2
</TextBlock>