Bootstrap 4 responsive tables won't take up 100% width

If you're using V4.1, and according to their docs, don't assign .table-responsive directly to the table. The table should be .table and if you want it to be horizontally scrollable (responsive) add it inside a .table-responsive container (a <div>, for instance).

Responsive tables allow tables to be scrolled horizontally with ease. Make any table responsive across all viewports by wrapping a .table with .table-responsive.

<div class="table-responsive">
  <table class="table">
  ...
  </table>
</div>

doing that, no extra css is needed.

In the OP's code, .table-responsive can be used alongside with the .col-md-12 on the outside .

/etc/apt/sources.list" E212: Can't open file for writing

I got this error when my directory path is incorrect, ensure your directory names and path are correct

onclick="javascript:history.go(-1)" not working in Chrome

Try this:

<a href="www.mypage.com" onclick="history.go(-1); return false;"> Link </a>

SQL RANK() over PARTITION on joined tables

As the rank doesn't depend at all from the contacts

RANKED_RSLTS

 QRY_ID  |  RES_ID  |  SCORE |  RANK
-------------------------------------
   A     |    1     |    15  |   3
   A     |    2     |    32  |   1
   A     |    3     |    29  |   2
   C     |    7     |    61  |   1
   C     |    9     |    30  |   2

Thus :

SELECT
    C.*
    ,R.SCORE
    ,MYRANK
FROM CONTACTS C LEFT JOIN
(SELECT  *,
 MYRANK = RANK() OVER (PARTITION BY QRY_ID ORDER BY SCORE DESC)
  FROM RSLTS)  R
ON C.RES_ID = R.RES_ID
AND C.QRY_ID = R.QRY_ID

How do I resolve the "java.net.BindException: Address already in use: JVM_Bind" error?

You have another process running on the same port.

You could try killing one of the java.exe services running in your task manager - ps make sure you dont kill eclipse since that is listed as java.exe as well. If nothing else works, restarting your machine will fix it anyhow. It looks like youre not shutting down a socket from a previous test. Hope this helps.

Twitter Bootstrap 3 Sticky Footer

Referring to the official Boostrap3 sticky footer example, there is no need to add <div id="push"></div>, and the CSS is simpler.

The CSS used in the official example is:

/* Sticky footer styles
-------------------------------------------------- */

html,
body {
  height: 100%;
  /* The html and body elements cannot have any padding or margin. */
}

/* Wrapper for page content to push down footer */
#wrap {
  min-height: 100%;
  height: auto;
  /* Negative indent footer by its height */
  margin: 0 auto -60px;
  /* Pad bottom by footer height */
  padding: 0 0 60px;
}

/* Set the fixed height of the footer here */
#footer {
  height: 60px;
  background-color: #f5f5f5;
}

and the essential HTML:

<body>

    <!-- Wrap all page content here -->
    <div id="wrap">

      <!-- Begin page content -->
      <div class="container">

      </div>
    </div>

    <div id="footer">
      <div class="container">

      </div>
    </div>
</body>

You can find the link for this css in the sticky-footer example's source code.

<!-- Custom styles for this template -->
<link href="sticky-footer.css" rel="stylesheet">

Full URL : http://getbootstrap.com/examples/sticky-footer/sticky-footer.css

Can not connect to local PostgreSQL

I had this problem plaguing me, and upon further investigation (running rake db:setup), I saw that rails was trying to connect to a previously used postgres instance - one which was stored in env variables as DATABASE_URL.

The fix: unset DATABASE_URL

source: https://stackoverflow.com/a/17420624/2577622

When I run `npm install`, it returns with `ERR! code EINTEGRITY` (npm 5.3.0)

Try the following:

npm cache clean --force

This has worked for me.

Where is PHP.ini in Mac OS X Lion? Thought it was in /usr/local/php5/lib

How to compare dates in c#

If you have date in DateTime variable then its a DateTime object and doesn't contain any format. Formatted date are expressed as string when you call DateTime.ToString method and provide format in it.

Lets say you have two DateTime variable, you can use the compare method for comparision,

DateTime date1 = new DateTime(2009, 8, 1, 0, 0, 0);
DateTime date2 = new DateTime(2009, 8, 2, 0, 0, 0);
int result = DateTime.Compare(date1, date2);
string relationship;

if (result < 0)
   relationship = "is earlier than";
else if (result == 0)
   relationship = "is the same time as";         
else
   relationship = "is later than";

Code snippet taken from msdn.

Convert object string to JSON

Use simple code in the link below :

http://msdn.microsoft.com/es-es/library/ie/cc836466%28v=vs.94%29.aspx

var jsontext = '{"firstname":"Jesper","surname":"Aaberg","phone":["555-0100","555-0120"]}';
var contact = JSON.parse(jsontext);

and reverse

var str = JSON.stringify(arr);

Html.Partial vs Html.RenderPartial & Html.Action vs Html.RenderAction

Html.Partial: returns MvcHtmlString and slow

Html.RenderPartial: directly render/write on output stream and returns void and it's very fast in comparison to Html.Partial

How can I pass a class member function as a callback?

That doesn't work because a member function pointer cannot be handled like a normal function pointer, because it expects a "this" object argument.

Instead you can pass a static member function as follows, which are like normal non-member functions in this regard:

m_cRedundencyManager->Init(&CLoggersInfra::Callback, this);

The function can be defined as follows

static void Callback(int other_arg, void * this_pointer) {
    CLoggersInfra * self = static_cast<CLoggersInfra*>(this_pointer);
    self->RedundencyManagerCallBack(other_arg);
}

Understanding timedelta

why do I have to pass seconds = uptime to timedelta

Because timedelta objects can be passed seconds, milliseconds, days, etc... so you need to specify what are you passing in (this is why you use the explicit key). Typecasting to int is superfluous as they could also accept floats.

and why does the string casting works so nicely that I get HH:MM:SS ?

It's not the typecasting that formats, is the internal __str__ method of the object. In fact you will achieve the same result if you write:

print datetime.timedelta(seconds=int(uptime))

How to delete the contents of a folder?

Notes: in case someone down voted my answer, I have something to explain here.

Everyone likes short 'n' simple answers. However, sometimes the reality is not so simple.
Back to my answer. I know shutil.rmtree() could be used to delete a directory tree. I've used it many times in my own projects. But you must realize that the directory itself will also be deleted by shutil.rmtree(). While this might be acceptable for some, it's not a valid answer for deleting the contents of a folder (without side effects).
I'll show you an example of the side effects. Suppose that you have a directory with customized owner and mode bits, where there are a lot of contents. Then you delete it with shutil.rmtree() and rebuild it with os.mkdir(). And you'll get an empty directory with default (inherited) owner and mode bits instead. While you might have the privilege to delete the contents and even the directory, you might not be able to set back the original owner and mode bits on the directory (e.g. you're not a superuser).
Finally, be patient and read the code. It's long and ugly (in sight), but proven to be reliable and efficient (in use).

Here's a long and ugly, but reliable and efficient solution.

It resolves a few problems which are not addressed by the other answerers:

It correctly handles symbolic links, including not calling shutil.rmtree() on a symbolic link (which will pass the os.path.isdir() test if it links to a directory; even the result of os.walk() contains symbolic linked directories as well).
It handles read-only files nicely.

Here's the code (the only useful function is clear_dir()):

import os
import stat
import shutil


# http://stackoverflow.com/questions/1889597/deleting-directory-in-python
def _remove_readonly(fn, path_, excinfo):
    # Handle read-only files and directories
    if fn is os.rmdir:
        os.chmod(path_, stat.S_IWRITE)
        os.rmdir(path_)
    elif fn is os.remove:
        os.lchmod(path_, stat.S_IWRITE)
        os.remove(path_)


def force_remove_file_or_symlink(path_):
    try:
        os.remove(path_)
    except OSError:
        os.lchmod(path_, stat.S_IWRITE)
        os.remove(path_)


# Code from shutil.rmtree()
def is_regular_dir(path_):
    try:
        mode = os.lstat(path_).st_mode
    except os.error:
        mode = 0
    return stat.S_ISDIR(mode)


def clear_dir(path_):
    if is_regular_dir(path_):
        # Given path is a directory, clear its content
        for name in os.listdir(path_):
            fullpath = os.path.join(path_, name)
            if is_regular_dir(fullpath):
                shutil.rmtree(fullpath, onerror=_remove_readonly)
            else:
                force_remove_file_or_symlink(fullpath)
    else:
        # Given path is a file or a symlink.
        # Raise an exception here to avoid accidentally clearing the content
        # of a symbolic linked directory.
        raise OSError("Cannot call clear_dir() on a symbolic link")

What is the JSF resource library for and how should it be used?

Actually, all of those examples on the web wherein the common content/file type like "js", "css", "img", etc is been used as library name are misleading.

Real world examples

To start, let's look at how existing JSF implementations like Mojarra and MyFaces and JSF component libraries like PrimeFaces and OmniFaces use it. No one of them use resource libraries this way. They use it (under the covers, by @ResourceDependency or UIViewRoot#addComponentResource()) the following way:

<h:outputScript library="javax.faces" name="jsf.js" />
<h:outputScript library="primefaces" name="jquery/jquery.js" />
<h:outputScript library="omnifaces" name="omnifaces.js" />
<h:outputScript library="omnifaces" name="fixviewstate.js" />
<h:outputScript library="omnifaces.combined" name="[dynamicname].js" />
<h:outputStylesheet library="primefaces" name="primefaces.css" />
<h:outputStylesheet library="primefaces-aristo" name="theme.css" />
<h:outputStylesheet library="primefaces-vader" name="theme.css" />

It should become clear that it basically represents the common library/module/theme name where all of those resources commonly belong to.

Easier identifying

This way it's so much easier to specify and distinguish where those resources belong to and/or are coming from. Imagine that you happen to have a primefaces.css resource in your own webapp wherein you're overriding/finetuning some default CSS of PrimeFaces; if PrimeFaces didn't use a library name for its own primefaces.css, then the PrimeFaces own one wouldn't be loaded, but instead the webapp-supplied one, which would break the look'n'feel.

Also, when you're using a custom ResourceHandler, you can also apply more finer grained control over resources coming from a specific library when library is used the right way. If all component libraries would have used "js" for all their JS files, how would the ResourceHandler ever distinguish if it's coming from a specific component library? Examples are OmniFaces CombinedResourceHandler and GraphicResourceHandler; check the createResource() method wherein the library is checked before delegating to next resource handler in chain. This way they know when to create CombinedResource or GraphicResource for the purpose.

Noted should be that RichFaces did it wrong. It didn't use any library at all and homebrewed another resource handling layer over it and it's therefore impossible to programmatically identify RichFaces resources. That's exactly the reason why OmniFaces CombinedResourceHander had to introduce a reflection-based hack in order to get it to work anyway with RichFaces resources.

Your own webapp

Your own webapp does not necessarily need a resource library. You'd best just omit it.

<h:outputStylesheet name="css/style.css" />
<h:outputScript name="js/script.js" />
<h:graphicImage name="img/logo.png" />

Or, if you really need to have one, you can just give it a more sensible common name, like "default" or some company name.

<h:outputStylesheet library="default" name="css/style.css" />
<h:outputScript library="default" name="js/script.js" />
<h:graphicImage library="default" name="img/logo.png" />

Or, when the resources are specific to some master Facelets template, you could also give it the name of the template, so that it's easier to relate each other. In other words, it's more for self-documentary purposes. E.g. in a /WEB-INF/templates/layout.xhtml template file:

<h:outputStylesheet library="layout" name="css/style.css" />
<h:outputScript library="layout" name="js/script.js" />

And a /WEB-INF/templates/admin.xhtml template file:

<h:outputStylesheet library="admin" name="css/style.css" />
<h:outputScript library="admin" name="js/script.js" />

For a real world example, check the OmniFaces showcase source code.

Or, when you'd like to share the same resources over multiple webapps and have created a "common" project for that based on the same example as in this answer which is in turn embedded as JAR in webapp's /WEB-INF/lib, then also reference it as library (name is free to your choice; component libraries like OmniFaces and PrimeFaces also work that way):

<h:outputStylesheet library="common" name="css/style.css" />
<h:outputScript library="common" name="js/script.js" />
<h:graphicImage library="common" name="img/logo.png" />

Library versioning

Another main advantage is that you can apply resource library versioning the right way on resources provided by your own webapp (this doesn't work for resources embedded in a JAR). You can create a direct child subfolder in the library folder with a name in the \d+(_\d+)* pattern to denote the resource library version.

WebContent
 |-- resources
 |    `-- default
 |         `-- 1_0
 |              |-- css
 |              |    `-- style.css
 |              |-- img
 |              |    `-- logo.png
 |              `-- js
 |                   `-- script.js
 :

When using this markup:

<h:outputStylesheet library="default" name="css/style.css" />
<h:outputScript library="default" name="js/script.js" />
<h:graphicImage library="default" name="img/logo.png" />

This will generate the following HTML with the library version as v parameter:

<link rel="stylesheet" type="text/css" href="/contextname/javax.faces.resource/css/style.css.xhtml?ln=default&amp;v=1_0" />
<script type="text/javascript" src="/contextname/javax.faces.resource/js/script.js.xhtml?ln=default&amp;v=1_0"></script>
<img src="/contextname/javax.faces.resource/img/logo.png.xhtml?ln=default&amp;v=1_0" alt="" />

So, if you have edited/updated some resource, then all you need to do is to copy or rename the version folder into a new value. If you have multiple version folders, then the JSF ResourceHandler will automatically serve the resource from the highest version number, according to numerical ordering rules.

So, when copying/renaming resources/default/1_0/* folder into resources/default/1_1/* like follows:

WebContent
 |-- resources
 |    `-- default
 |         |-- 1_0
 |         |    :
 |         |
 |         `-- 1_1
 |              |-- css
 |              |    `-- style.css
 |              |-- img
 |              |    `-- logo.png
 |              `-- js
 |                   `-- script.js
 :

Then the last markup example would generate the following HTML:

<link rel="stylesheet" type="text/css" href="/contextname/javax.faces.resource/css/style.css.xhtml?ln=default&amp;v=1_1" />
<script type="text/javascript" src="/contextname/javax.faces.resource/js/script.js.xhtml?ln=default&amp;v=1_1"></script>
<img src="/contextname/javax.faces.resource/img/logo.png.xhtml?ln=default&amp;v=1_1" alt="" />

This will force the webbrowser to request the resource straight from the server instead of showing the one with the same name from the cache, when the URL with the changed parameter is been requested for the first time. This way the endusers aren't required to do a hard refresh (Ctrl+F5 and so on) when they need to retrieve the updated CSS/JS resource.

Please note that library versioning is not possible for resources enclosed in a JAR file. You'd need a custom ResourceHandler. See also How to use JSF versioning for resources in jar.

How to capture a JFrame's close button click event?

import javax.swing.JOptionPane;
import javax.swing.JFrame;

/*Some piece of code*/
frame.addWindowListener(new java.awt.event.WindowAdapter() {
    @Override
    public void windowClosing(java.awt.event.WindowEvent windowEvent) {
        if (JOptionPane.showConfirmDialog(frame, 
            "Are you sure you want to close this window?", "Close Window?", 
            JOptionPane.YES_NO_OPTION,
            JOptionPane.QUESTION_MESSAGE) == JOptionPane.YES_OPTION){
            System.exit(0);
        }
    }
});

If you also want to prevent the window from closing unless the user chooses 'Yes', you can add:

frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

Postgres integer arrays as parameters?

You can always use a properly formatted string. The trick is the formatting.

command.Parameters.Add("@array_parameter", string.Format("{{{0}}}", string.Join(",", array));

Note that if your array is an array of strings, then you'll need to use array.Select(value => string.Format("\"{0}\", value)) or the equivalent. I use this style for an array of an enumerated type in PostgreSQL, because there's no automatic conversion from the array.

In my case, my enumerated type has some values like 'value1', 'value2', 'value3', and my C# enumeration has matching values. In my case, the final SQL query ends up looking something like (E'{"value1","value2"}'), and this works.

How do I check if an HTML element is empty using jQuery?

If by "empty", you mean with no HTML content,

if($('#element').html() == "") {
  //call function
}

Could not load type from assembly error

I experienced a similar issue in Visual Studio 2017 using MSTest as the testing framework. I was receiving System.TypeLoadException exceptions when running some (not all) unit tests, but those unit tests would pass when debugged. I ultimately did the following which solved the problem:

Open the Local.testsettings file in the solution
Go to the "Unit Test" settings
Uncheck the "Use the Load Context for assemblies in the test directory." checkbox

After taking these steps all unit tests started passing when run.

Redirect to an external URL from controller action in Spring MVC

Another way to do it is just to use the sendRedirect method:

@RequestMapping(
    value = "/",
    method = RequestMethod.GET)
public void redirectToTwitter(HttpServletResponse httpServletResponse) throws IOException {
    httpServletResponse.sendRedirect("https://twitter.com");
}

How do I include inline JavaScript in Haml?

I'm using fileupload-jquery in haml. The original js is below:

_x000D_

<!-- The template to display files available for download -->_x000D_
<script id="template-download" type="text/x-tmpl">_x000D_
  {% for (var i=0, file; file=o.files[i]; i++) { %}_x000D_
    <tr class="template-download fade">_x000D_
      {% if (file.error) { %}_x000D_
        <td></td>_x000D_
        <td class="name"><span>{%=file.name%}</span></td>_x000D_
        <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>_x000D_
        <td class="error" colspan="2"><span class="label label-important">{%=locale.fileupload.error%}</span> {%=locale.fileupload.errors[file.error] || file.error%}</td>_x000D_
        {% } else { %}_x000D_
        <td class="preview">{% if (file.thumbnail_url) { %}_x000D_
          <a href="{%=file.url%}" title="{%=file.name%}" rel="gallery" download="{%=file.name%}"><img src="{%=file.thumbnail_url%}"></a>_x000D_
          {% } %}</td>_x000D_
        <td class="name">_x000D_
          <a href="{%=file.url%}" title="{%=file.name%}" rel="{%=file.thumbnail_url&&'gallery'%}" download="{%=file.name%}">{%=file.name%}</a>_x000D_
        </td>_x000D_
        <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>_x000D_
        <td colspan="2"></td>_x000D_
        {% } %}_x000D_
      <td class="delete">_x000D_
        <button class="btn btn-danger" data-type="{%=file.delete_type%}" data-url="{%=file.delete_url%}">_x000D_
          <i class="icon-trash icon-white"></i>_x000D_
          <span>{%=locale.fileupload.destroy%}</span>_x000D_
        </button>_x000D_
        <input type="checkbox" name="delete" value="1">_x000D_
      </td>_x000D_
    </tr>_x000D_
    {% } %}_x000D_
</script>

_x000D_

At first I used the :cdata to convert (from html2haml), it doesn't work properly (Delete button can't remove relevant component in callback).

_x000D_

<script id='template-download' type='text/x-tmpl'>_x000D_
      <![CDATA[_x000D_
          {% for (var i=0, file; file=o.files[i]; i++) { %}_x000D_
          <tr class="template-download fade">_x000D_
          {% if (file.error) { %}_x000D_
          <td></td>_x000D_
          <td class="name"><span>{%=file.name%}</span></td>_x000D_
          <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>_x000D_
          <td class="error" colspan="2"><span class="label label-important">{%=locale.fileupload.error%}</span> {%=locale.fileupload.errors[file.error] || file.error%}</td>_x000D_
          {% } else { %}_x000D_
          <td class="preview">{% if (file.thumbnail_url) { %}_x000D_
          <a href="{%=file.url%}" title="{%=file.name%}" rel="gallery" download="{%=file.name%}"><img src="{%=file.thumbnail_url%}"></a>_x000D_
          {% } %}</td>_x000D_
          <td class="name">_x000D_
          <a href="{%=file.url%}" title="{%=file.name%}" rel="{%=file.thumbnail_url&&'gallery'%}" download="{%=file.name%}">{%=file.name%}</a>_x000D_
          </td>_x000D_
          <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>_x000D_
          <td colspan="2"></td>_x000D_
          {% } %}_x000D_
          <td class="delete">_x000D_
          <button class="btn btn-danger" data-type="{%=file.delete_type%}" data-url="{%=file.delete_url%}">_x000D_
          <i class="icon-trash icon-white"></i>_x000D_
          <span>{%=locale.fileupload.destroy%}</span>_x000D_
          </button>_x000D_
          <input type="checkbox" name="delete" value="1">_x000D_
          </td>_x000D_
          </tr>_x000D_
          {% } %}_x000D_
      ]]>_x000D_
    </script>

_x000D_

So I use :plain filter:

_x000D_

%script#template-download{:type => "text/x-tmpl"}_x000D_
  :plain_x000D_
    {% for (var i=0, file; file=o.files[i]; i++) { %}_x000D_
    <tr class="template-download fade">_x000D_
    {% if (file.error) { %}_x000D_
    <td></td>_x000D_
    <td class="name"><span>{%=file.name%}</span></td>_x000D_
    <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>_x000D_
    <td class="error" colspan="2"><span class="label label-important">{%=locale.fileupload.error%}</span> {%=locale.fileupload.errors[file.error] || file.error%}</td>_x000D_
    {% } else { %}_x000D_
    <td class="preview">{% if (file.thumbnail_url) { %}_x000D_
    <a href="{%=file.url%}" title="{%=file.name%}" rel="gallery" download="{%=file.name%}"><img src="{%=file.thumbnail_url%}"></a>_x000D_
    {% } %}</td>_x000D_
    <td class="name">_x000D_
    <a href="{%=file.url%}" title="{%=file.name%}" rel="{%=file.thumbnail_url&&'gallery'%}" download="{%=file.name%}">{%=file.name%}</a>_x000D_
    </td>_x000D_
    <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>_x000D_
    <td colspan="2"></td>_x000D_
    {% } %}_x000D_
    <td class="delete">_x000D_
    <button class="btn btn-danger" data-type="{%=file.delete_type%}" data-url="{%=file.delete_url%}">_x000D_
    <i class="icon-trash icon-white"></i>_x000D_
    <span>{%=locale.fileupload.destroy%}</span>_x000D_
    </button>_x000D_
    <input type="checkbox" name="delete" value="1">_x000D_
    </td>_x000D_
    </tr>_x000D_
    {% } %}

_x000D_

The converted result is exactly the same as the original.

So :plain filter in this senario fits my need.

:plain Does not parse the filtered text. This is useful for large blocks of text without HTML tags, when you don’t want lines starting with . or - to be parsed.

For more detail, please refer to haml.info

How to focus on a form input text field on page load using jQuery?

Sorry for bumping an old question. I found this via google.

Its also worth noting that its possible to use more than one selector, thus you can target any form element, and not just one specific type.

eg.

$('#myform input,#myform textarea').first().focus();

This will focus the first input or textarea it finds, and of course you can add other selectors into the mix as well. Handy if you can't be certain of a specific element type being first, or if you want something a bit general/reusable.

find index of an int in a list

Use the .IndexOf() method of the list. Specs for the method can be found on MSDN.

How to process a file in PowerShell line-by-line as a stream

System.IO.File.ReadLines() is perfect for this scenario. It returns all the lines of a file, but lets you begin iterating over the lines immediately which means it does not have to store the entire contents in memory.

Requires .NET 4.0 or higher.

foreach ($line in [System.IO.File]::ReadLines($filename)) {
    # do something with $line
}

http://msdn.microsoft.com/en-us/library/dd383503.aspx

"fatal: Not a git repository (or any of the parent directories)" from git status

I just got this message and there is a very simple answer before trying the others. At the parent directory, type git init

This will initialize the directory for git. Then git add and git commit should work.

How to hide the border for specified rows of a table?

I use this with good results:

border-style:hidden;

It also works for:

border-right-style:hidden; /*if you want to hide just a border on a cell*/

Example:

_x000D_

<style type="text/css">_x000D_
      table, th, td {_x000D_
       border: 2px solid green;_x000D_
      }_x000D_
      tr.hide_right > td, td.hide_right{_x000D_
        border-right-style:hidden;_x000D_
      }_x000D_
      tr.hide_all > td, td.hide_all{_x000D_
        border-style:hidden;_x000D_
      }_x000D_
  }_x000D_
</style>_x000D_
<table>_x000D_
  <tr>_x000D_
    <td class="hide_right">11</td>_x000D_
    <td>12</td>_x000D_
    <td class="hide_all">13</td>_x000D_
  </tr>_x000D_
  <tr class="hide_right">_x000D_
    <td>21</td>_x000D_
    <td>22</td>_x000D_
    <td>23</td>_x000D_
  </tr>_x000D_
  <tr class="hide_all">_x000D_
    <td>31</td>_x000D_
    <td>32</td>_x000D_
    <td>33</td>_x000D_
  </tr>_x000D_
</table>

_x000D_

Here is the result:

how to install python distutils

The simplest way to install setuptools when it isn't already there and you can't use a package manager is to download ez_setup.py and run it with the appropriate Python interpreter. This works even if you have multiple versions of Python around: just run ez_setup.py once with each Python.

Edit: note that recent versions of Python 3 include setuptools in the distribution so you no longer need to install separately. The script mentioned here is only relevant for old versions of Python.

How to iterate through table in Lua?

All the answers here suggest to use ipairs but beware, it does not work all the time.

t = {[2] = 44, [4]=77, [6]=88}

--This for loop prints the table
for key,value in next,t,nil do 
  print(key,value) 
end

--This one does not print the table
for key,value in ipairs(t) do 
  print(key,value) 
end

How to add rows dynamically into table layout

You are doing it right; every time you need to add a row, simply so new TableRow(), etc. It might be easier for you to inflate the new row from XML though.

Correct way of looping through C++ arrays

How about:

#include <iostream>
#include <array>
#include <algorithm>

int main ()
{
    std::array<std::string, 3> text = {"Apple", "Banana", "Orange"};
    std::for_each(text.begin(), text.end(), [](std::string &string){ std::cout << string << "\n"; });

    return 0;
}

Compiles and works with C++ 11 and has no 'raw' looping :)

Refused to execute script, strict MIME type checking is enabled?

My problem was that I have been putting the CSS files in the scripts definition area just above the end of the Try to check the files spots within your pages

Set markers for individual points on a line in Matplotlib

There is a picture show all markers' name and description, i hope it will help you.

import matplotlib.pylab as plt
markers=['.',',','o','v','^','<','>','1','2','3','4','8','s','p','P','*','h','H','+','x','X','D','d','|','_']
descriptions=['point', 'pixel', 'circle', 'triangle_down', 'triangle_up','triangle_left', 'triangle_right', 'tri_down', 'tri_up', 'tri_left','tri_right', 'octagon', 'square', 'pentagon', 'plus (filled)','star', 'hexagon1', 'hexagon2', 'plus', 'x', 'x (filled)','diamond', 'thin_diamond', 'vline', 'hline']
x=[]
y=[]
for i in range(5):
    for j in range(5):
        x.append(i)
        y.append(j)
plt.figure()
for i,j,m,l in zip(x,y,markers,descriptions):
    plt.scatter(i,j,marker=m)
    plt.text(i-0.15,j+0.15,s=m+' : '+l)
plt.axis([-0.1,4.8,-0.1,4.5])
plt.tight_layout()
plt.axis('off')
plt.show()

example1

Retrieve a single file from a repository

If your Git repository hosted on Azure-DevOps (VSTS) you can retrieve a single file with Rest API.

The format of this API looks like this:

 https://dev.azure.com/{organization}/_apis/git/repositories/{repositoryId}/items?path={pathToFile}&api-version=4.1?download=true

For example:

 https://dev.azure.com/{organization}/_apis/git/repositories/278d5cd2-584d-4b63-824a-2ba458937249/items?scopePath=/MyWebSite/MyWebSite/Views/Home/_Home.cshtml&download=true&api-version=4.1

Angularjs error Unknown provider

bmleite has the correct answer about including the module.

If that is correct in your situation, you should also ensure that you are not redefining the modules in multiple files.

Remember:

angular.module('ModuleName', [])   // creates a module.

angular.module('ModuleName')       // gets you a pre-existing module.

So if you are extending a existing module, remember not to overwrite when trying to fetch it.

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

As others have said you are "tainting" the canvas by loading from a cross origins domain.

https://developer.mozilla.org/en-US/docs/HTML/CORS_Enabled_Image

However, you may be able to prevent this by simply setting:

img.crossOrigin = "Anonymous";

This only works if the remote server sets the following header appropriately:

Access-Control-Allow-Origin "*"

The Dropbox file chooser when using the "direct link" option is a great example of this. I use it on oddprints.com to hoover up images from the remote dropbox image url, into my canvas, and then submit the image data back into my server. All in javascript

did you register the component correctly? For recursive components, make sure to provide the "name" option

In my case (quasar and command quasar dev for testing), I just forgot to restart dev Quasar command.

It seemed to me that components was automatically loaded when any change was done. But in this case, I reused component in another page and I got this message.

Decode HTML entities in Python string?

Beautiful Soup 4 allows you to set a formatter to your output

If you pass in formatter=None, Beautiful Soup will not modify strings at all on output. This is the fastest option, but it may lead to Beautiful Soup generating invalid HTML/XML, as in these examples:

print(soup.prettify(formatter=None))
# <html>
#  <body>
#   <p>
#    Il a dit <<Sacré bleu!>>
#   </p>
#  </body>
# </html>

link_soup = BeautifulSoup('<a href="http://example.com/?foo=val1&bar=val2">A link</a>')
print(link_soup.a.encode(formatter=None))
# <a href="http://example.com/?foo=val1&bar=val2">A link</a>

PostgreSQL unnest() with element number

Use Subscript Generating Functions.
http://www.postgresql.org/docs/current/static/functions-srf.html#FUNCTIONS-SRF-SUBSCRIPTS

For example:

SELECT 
  id
  , elements[i] AS elem
  , i AS nr
FROM
  ( SELECT 
      id
      , elements
      , generate_subscripts(elements, 1) AS i
    FROM
      ( SELECT
          id
          , string_to_array(elements, ',') AS elements
        FROM
          myTable
      ) AS foo
  ) bar
;

More simply:

SELECT
  id
  , unnest(elements) AS elem
  , generate_subscripts(elements, 1) AS nr
FROM
  ( SELECT
      id
      , string_to_array(elements, ',') AS elements
    FROM
      myTable
  ) AS foo
;

Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")

This should be

compile("org.springframework.boot:spring-boot-starter-tomcat")

How to get the number of threads in a Java process

Using Linux Top command

top -H -p (process id)

you could get process id of one program by this method :

ps aux | grep (your program name)

for example :

ps aux | grep user.py

Possible to perform cross-database queries with PostgreSQL?

I have checked and tried to create a foreign key relationships between 2 tables in 2 different databases using both dblink and postgres_fdw but with no result.

Having read the other peoples feedback on this, for example here and here and in some other sources it looks like there is no way to do that currently:

The dblink and postgres_fdw indeed enable one to connect to and query tables in other databases, which is not possible with the standard Postgres, but they do not allow to establish foreign key relationships between tables in different databases.

How do I insert an image in an activity with android studio?

since you followed the tutorial, I presume you have a screen that says Hello World.

that means you have some code in your layout xml that looks like this

<TextView        
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world" />

you want to display an image, so instead of TextView you want to have ImageView. and instead of a text attribute you want an src attribute, that links to your drawable resource

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/cool_pic"
/>

Declare Variable for a Query String

Using EXEC

You can use following example for building SQL statement.

DECLARE @sqlCommand varchar(1000)
DECLARE @columnList varchar(75)
DECLARE @city varchar(75)
SET @columnList = 'CustomerID, ContactName, City'
SET @city = '''London'''
SET @sqlCommand = 'SELECT ' + @columnList + ' FROM customers WHERE City = ' + @city
EXEC (@sqlCommand)

Using sp_executesql

With using this approach you can ensure that the data values being passed into the query are the correct datatypes and avoind use of more quotes.

DECLARE @sqlCommand nvarchar(1000)
DECLARE @columnList varchar(75)
DECLARE @city varchar(75)
SET @columnList = 'CustomerID, ContactName, City'
SET @city = 'London'
SET @sqlCommand = 'SELECT ' + @columnList + ' FROM customers WHERE City = @city'
EXECUTE sp_executesql @sqlCommand, N'@city nvarchar(75)', @city = @city

Reference

How do I scroll the UIScrollView when the keyboard appears?

Swift 4.2 solution that takes possible heights of UIToolbar and UITabBar into account.

private func setupKeyboardNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIControl.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIControl.keyboardWillHideNotification, object: nil)
}

@objc func keyboardWillShow(_ notification: Notification) {
    let userInfo: NSDictionary = notification.userInfo! as NSDictionary
    let keyboardSize = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.size

    let tabbarHeight = tabBarController?.tabBar.frame.size.height ?? 0
    let toolbarHeight = navigationController?.toolbar.frame.size.height ?? 0
    let bottomInset = keyboardSize.height - tabbarHeight - toolbarHeight

    scrollView.contentInset.bottom = bottomInset
    scrollView.scrollIndicatorInsets.bottom = bottomInset
}

@objc func keyboardWillHide(_ notification: Notification) {
    scrollView.contentInset = .zero
    scrollView.scrollIndicatorInsets = .zero
}

And, if you're targeting < iOS 9, you have to unregister the observer at some point (thanks Joe)

java.lang.ClassNotFoundException: Didn't find class on path: dexpathlist

If you are enabled minifyEnabled and shrinkResources to true in your app gradle file. You need to add the following line in proguard-rules.pro file

-keep class com.yourpackage_name.** { *; }

because minification is removed some important classes in our apk file.

HTML Form Redirect After Submit

Try this Javascript (jquery) code. Its an ajax request to an external URL. Use the callback function to fire any code:

<script type="text/javascript">
$(function() {
  $('form').submit(function(){
    $.post('http://example.com/upload', function() {
      window.location = 'http://google.com';
    });
    return false;
  });
});
</script>

Connect to docker container as user other than root

Execute command as www-data user: docker exec -t --user www-data container bash -c "ls -la"

"Undefined reference to" template class constructor

This is a common question in C++ programming. There are two valid answers to this. There are advantages and disadvantages to both answers and your choice will depend on context. The common answer is to put all the implementation in the header file, but there's another approach will will be suitable in some cases. The choice is yours.

The code in a template is merely a 'pattern' known to the compiler. The compiler won't compile the constructors cola<float>::cola(...) and cola<string>::cola(...) until it is forced to do so. And we must ensure that this compilation happens for the constructors at least once in the entire compilation process, or we will get the 'undefined reference' error. (This applies to the other methods of cola<T> also.)

Understanding the problem

The problem is caused by the fact that main.cpp and cola.cpp will be compiled separately first. In main.cpp, the compiler will implicitly instantiate the template classes cola<float> and cola<string> because those particular instantiations are used in main.cpp. The bad news is that the implementations of those member functions are not in main.cpp, nor in any header file included in main.cpp, and therefore the compiler can't include complete versions of those functions in main.o. When compiling cola.cpp, the compiler won't compile those instantiations either, because there are no implicit or explicit instantiations of cola<float> or cola<string>. Remember, when compiling cola.cpp, the compiler has no clue which instantiations will be needed; and we can't expect it to compile for every type in order to ensure this problem never happens! (cola<int>, cola<char>, cola<ostream>, cola< cola<int> > ... and so on ...)

The two answers are:

Tell the compiler, at the end of cola.cpp, which particular template classes will be required, forcing it to compile cola<float> and cola<string>.
Put the implementation of the member functions in a header file that will be included every time any other 'translation unit' (such as main.cpp) uses the template class.

Answer 1: Explicitly instantiate the template, and its member definitions

At the end of cola.cpp, you should add lines explicitly instantiating all the relevant templates, such as

template class cola<float>;
template class cola<string>;

and you add the following two lines at the end of nodo_colaypila.cpp:

template class nodo_colaypila<float>;
template class nodo_colaypila<std :: string>;

This will ensure that, when the compiler is compiling cola.cpp that it will explicitly compile all the code for the cola<float> and cola<string> classes. Similarly, nodo_colaypila.cpp contains the implementations of the nodo_colaypila<...> classes.

In this approach, you should ensure that all the of the implementation is placed into one .cpp file (i.e. one translation unit) and that the explicit instantation is placed after the definition of all the functions (i.e. at the end of the file).

Answer 2: Copy the code into the relevant header file

The common answer is to move all the code from the implementation files cola.cpp and nodo_colaypila.cpp into cola.h and nodo_colaypila.h. In the long run, this is more flexible as it means you can use extra instantiations (e.g. cola<char>) without any more work. But it could mean the same functions are compiled many times, once in each translation unit. This is not a big problem, as the linker will correctly ignore the duplicate implementations. But it might slow down the compilation a little.

Summary

The default answer, used by the STL for example and in most of the code that any of us will write, is to put all the implementations in the header files. But in a more private project, you will have more knowledge and control of which particular template classes will be instantiated. In fact, this 'bug' might be seen as a feature, as it stops users of your code from accidentally using instantiations you have not tested for or planned for ("I know this works for cola<float> and cola<string>, if you want to use something else, tell me first and will can verify it works before enabling it.").

Finally, there are three other minor typos in the code in your question:

You are missing an #endif at the end of nodo_colaypila.h
in cola.h nodo_colaypila<T>* ult, pri; should be nodo_colaypila<T> *ult, *pri; - both are pointers.
nodo_colaypila.cpp: The default parameter should be in the header file nodo_colaypila.h, not in this implementation file.

Multiple SQL joins

It will be something like this:

SELECT b.Title, b.Edition, b.Year, b.Pages, b.Rating, c.Category, p.Publisher, w.LastName
FROM
    Books b
    JOIN Categories_Book cb ON cb._ISBN = b._Books_ISBN
    JOIN Category c ON c._CategoryID = cb._Categories_Category_ID
    JOIN Publishers p ON p._PublisherID = b.PublisherID
    JOIN Writers_Books wb ON wb._Books_ISBN = b._ISBN
    JOIN Writer w ON w._WritersID = wb._Writers_WriterID

You use the join statement to indicate which fields from table A map to table B. I'm using aliases here thats why you see Books b the Books table will be referred to as b in the rest of the query. This makes for less typing.

FYI your naming convention is very strange, I would expect it to be more like this:

Book: ID, ISBN , BookTitle, Edition, Year, PublisherID, Pages, Rating
Category: ID, [Name]
BookCategory: ID, CategoryID, BookID
Publisher: ID, [Name]
Writer: ID, LastName
BookWriter: ID, WriterID, BookID

JavaScript global event mechanism

You listen to the onerror event by assigning a function to window.onerror:

 window.onerror = function (msg, url, lineNo, columnNo, error) {
        var string = msg.toLowerCase();
        var substring = "script error";
        if (string.indexOf(substring) > -1){
            alert('Script Error: See Browser Console for Detail');
        } else {
            alert(msg, url, lineNo, columnNo, error);
        }   
      return false; 
  };

what is the difference between GROUP BY and ORDER BY in sql

ORDER BY: sort the data in ascending or descending order.

Consider the CUSTOMERS table:

+----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
|  2 | Khilan   |  25 | Delhi     |  1500.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
|  4 | Chaitali |  25 | Mumbai    |  6500.00 |
|  5 | Hardik   |  27 | Bhopal    |  8500.00 |
|  6 | Komal    |  22 | MP        |  4500.00 |
|  7 | Muffy    |  24 | Indore    | 10000.00 |
+----+----------+-----+-----------+----------+

Following is an example, which would sort the result in ascending order by NAME:

SQL> SELECT * FROM CUSTOMERS
     ORDER BY NAME;

This would produce the following result:

+----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  4 | Chaitali |  25 | Mumbai    |  6500.00 |
|  5 | Hardik   |  27 | Bhopal    |  8500.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
|  2 | Khilan   |  25 | Delhi     |  1500.00 |
|  6 | Komal    |  22 | MP        |  4500.00 |
|  7 | Muffy    |  24 | Indore    | 10000.00 |
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
+----+----------+-----+-----------+----------+

GROUP BY: arrange identical data into groups.

Now, CUSTOMERS table has the following records with duplicate names:

+----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
|  2 | Ramesh   |  25 | Delhi     |  1500.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
|  4 | kaushik  |  25 | Mumbai    |  6500.00 |
|  5 | Hardik   |  27 | Bhopal    |  8500.00 |
|  6 | Komal    |  22 | MP        |  4500.00 |
|  7 | Muffy    |  24 | Indore    | 10000.00 |
+----+----------+-----+-----------+----------+

if you want to group identical names into single name, then GROUP BY query would be as follows:

SQL> SELECT * FROM CUSTOMERS
     GROUP BY NAME;

This would produce the following result: (for identical names it would pick the last one and finally sort the column in ascending order)

    +----+----------+-----+-----------+----------+   
    | ID | NAME     | AGE | ADDRESS   | SALARY   |
    +----+----------+-----+-----------+----------+
    |  5 | Hardik   |  27 | Bhopal    |  8500.00 |
    |  4 | kaushik  |  25 | Mumbai    |  6500.00 |
    |  6 | Komal    |  22 | MP        |  4500.00 |
    |  7 | Muffy    |  24 | Indore    | 10000.00 |
    |  2 | Ramesh   |  25 | Delhi     |  1500.00 |
    +----+----------+-----+-----------+----------+

as you have inferred that it is of no use without SQL functions like sum,avg etc..

so go through this definition to understand the proper use of GROUP BY:

A GROUP BY clause works on the rows returned by a query by summarizing identical rows into a single/distinct group and returns a single row with the summary for each group, by using appropriate Aggregate function in the SELECT list, like COUNT(), SUM(), MIN(), MAX(), AVG(), etc.

Now, if you want to know the total amount of salary on each customer(name), then GROUP BY query would be as follows:

SQL> SELECT NAME, SUM(SALARY) FROM CUSTOMERS
     GROUP BY NAME;

This would produce the following result: (sum of the salaries of identical names and sort the NAME column after removing identical names)

+---------+-------------+
| NAME    | SUM(SALARY) |
+---------+-------------+
| Hardik  |     8500.00 |
| kaushik |     8500.00 |
| Komal   |     4500.00 |
| Muffy   |    10000.00 |
| Ramesh  |     3500.00 |
+---------+-------------+

How do I display a wordpress page content?

You can achieve this by adding this simple php code block

<?php if ( have_posts() ) : while ( have_posts() ) : the_post();
      the_content();
      endwhile; else: ?>
      <p>!Sorry no posts here</p>
<?php endif; ?>

error : expected unqualified-id before return in c++

if (chapeau) {

You forgot the ending brace to this if statement, so the subsequent else if is considered a syntax error. You need to add the brace when the if statement body is complete:

if (chapeau) {
    cout << "le Professeur Violet";
}
else if (moustaches) {
    cout << "le Colonel Moutarde";
}
// ...

Convert datetime object to a String of date only in Python

The sexiest version by far is with format strings.

from datetime import datetime

print(f'{datetime.today():%Y-%m-%d}')

Get top 1 row of each group

CROSS APPLY was the method I used for my solution, as it worked for me, and for my clients needs. And from what I've read, should provide the best overall performance should their database grow substantially.

Distinct by property of class with LINQ

Another extension method for Linq-to-Objects, without using GroupBy:

    /// <summary>
    /// Returns the set of items, made distinct by the selected value.
    /// </summary>
    /// <typeparam name="TSource">The type of the source.</typeparam>
    /// <typeparam name="TResult">The type of the result.</typeparam>
    /// <param name="source">The source collection.</param>
    /// <param name="selector">A function that selects a value to determine unique results.</param>
    /// <returns>IEnumerable&lt;TSource&gt;.</returns>
    public static IEnumerable<TSource> Distinct<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector)
    {
        HashSet<TResult> set = new HashSet<TResult>();

        foreach(var item in source)
        {
            var selectedValue = selector(item);

            if (set.Add(selectedValue))
                yield return item;
        }
    }

Efficient SQL test query or validation query that will work across all (or most) databases

Just found out the hard way that it is

SELECT 1 FROM DUAL

for MaxDB as well.

Using python's mock patch.object to change the return value of a method called within another method

This can be done with something like this:

# foo.py
class Foo:
    def method_1():
        results = uses_some_other_method()


# testing.py
from mock import patch

@patch('Foo.uses_some_other_method', return_value="specific_value"):
def test_some_other_method(mock_some_other_method):
    foo = Foo()
    the_value = foo.method_1()
    assert the_value == "specific_value"

Here's a source that you can read: Patching in the wrong place

Setting selected values for ng-options bound select elements

If using AngularJS 1.2 you can use 'track by' to tell Angular how to compare objects.

<select 
    ng-model="Choice.SelectedOption"                 
    ng-options="choice.Name for choice in Choice.Options track by choice.ID">
</select>

Updated fiddle http://jsfiddle.net/gFCzV/34/

Best way to convert an ArrayList to a string

In case you happen to be on Android and you are not using Jack yet (e.g. because it's still lacking support for Instant Run), and if you want more control over formatting of the resulting string (e.g. you would like to use the newline character as the divider of elements), and happen to use/want to use the StreamSupport library (for using streams on Java 7 or earlier versions of the compiler), you could use something like this (I put this method in my ListUtils class):

public static <T> String asString(List<T> list) {
    return StreamSupport.stream(list)
            .map(Object::toString)
            .collect(Collectors.joining("\n"));
}

And of course, make sure to implement toString() on your list objects' class.

Android change SDK version in Eclipse? Unable to resolve target android-x

I faced the same issue and got it working.

I think it is because when you import a project, build target is not set in the project properties which then default to the value used in manifest file. Most likely, you already have installed a later android API with your SDK.

The solution is to enable build target toward your installed API level (but keep the minimum api support as specified in the manifest file). TO do this, in project properties, go to android, and from "Project Build Target", pick a target name.

"SyntaxError: Unexpected token < in JSON at position 0"

My problem was that I was getting the data back in a string which was not in a proper JSON format, which I was then trying to parse it. simple example: JSON.parse('{hello there}') will give an error at h. In my case the callback url was returning an unnecessary character before the objects: employee_names([{"name":.... and was getting error at e at 0. My callback URL itself had an issue which when fixed, returned only objects.

Regular expression to find two strings anywhere in input

This is fairly easy on processing power required:

(string1(.|\n)*string2)|(string2(.|\n)*string1)

I used this in visual studio 2013 to find all files that had both string 1 and 2 in it.

How to write palindrome in JavaScript

Taking a stab at this. Kind of hard to measure performance, though.

function palin(word) {
    var i = 0,
        len = word.length - 1,
        max = word.length / 2 | 0;

    while (i < max) {
        if (word.charCodeAt(i) !== word.charCodeAt(len - i)) {
            return false;
        }
        i += 1;
    }
    return true;
}

My thinking is to use charCodeAt() instead charAt() with the hope that allocating a Number instead of a String will have better perf because Strings are variable length and might be more complex to allocate. Also, only iterating halfway through (as noted by sai) because that's all that's required. Also, if the length is odd (ex: 'aba'), the middle character is always ok.

What's the default password of mariadb on fedora?

For me, password = admin, worked. I installed it using pacman, Arch (Manjaro KDE).

NB: MariaDB was already installed, as a dependency of Amarok.

Text size and different android screen sizes

As @espinchi mentioned from 3.2 (API level 13) size groups are deprecated. Screen size ranges are the favored approach going forward.

Change SQLite database mode to read-write

This error usually happens when your database is accessed by one application already, and you're trying to access it with another application.

How can I see normal print output created during pytest run?

pytest --capture=tee-sys was recently added (v5.4.0). You can capture as well as see the output on stdout/err.

Ruby get object keys as array

Like taro said, keys returns the array of keys of your Hash:

http://ruby-doc.org/core-1.9.3/Hash.html#method-i-keys

You'll find all the different methods available for each class.

If you don't know what you're dealing with:

 puts my_unknown_variable.class.to_s

This will output the class name.

Simulate a specific CURL in PostMan

As mentioned in multiple answers above you can import the cURL in POSTMAN directly. But if URL is authorized (or is not working for some reason) ill suggest you can manually add all the data points as JSON in your postman body. take the API URL from the cURL.

for the Authorization part- just add an Authorization key and base 64 encoded string as value.

example:

curl -u rzp_test_26ccbdbfe0e84b:69b2e24411e384f91213f22a \ https://api.razorpay.com/v1/orders -X POST \ --data "amount=50000" \ --data "currency=INR" \ --data "receipt=Receipt #20" \ --data "payment_capture=1" https://api.razorpay.com/v1/orders

{ "amount": "5000", "currency": "INR", "receipt": "Receipt #20", "payment_capture": "1" }

Headers: Authorization:Basic cnpwX3Rlc3RfWEk5QW5TU0N3RlhjZ0Y6dURjVThLZ3JiQVVnZ3JNS***U056V25J where "cnpwX3Rlc3RfWEk5QW5TU0N3RlhjZ0Y6dURjVThLZ3JiQVVnZ3JNS***U056V25J" is the encoded form of "rzp_test_26ccbdbfe0e84b:69b2e24411e384f91213f22a"`

small tip: for encoding, you can easily go to your chrome console (right-click => inspect) and type : btoa("string you want to encode") ( or use postman basic authorization)

How to access SOAP services from iPhone

My solution was to have a proxy server accept REST, issue the SOAP request, and return result, using PHP.

Time to implement: 15-30 minutes.

Not most elegant, but solid.

Insert current date into a date column using T-SQL?

Couple of ways. Firstly, if you're adding a row each time a [de]activation occurs, you can set the column default to GETDATE() and not set the value in the insert. Otherwise,

UPDATE TableName SET [ColumnName] = GETDATE() WHERE UserId = @userId

How to create number input field in Flutter?

For those who are looking for making TextField or TextFormField accept only numbers as input, try this code block :

for flutter 1.20 or newer versions

TextFormField(
              controller: _controller,
              keyboardType: TextInputType.number,
              inputFormatters: <TextInputFormatter>[
                FilteringTextInputFormatter.allow(RegExp(r'[0-9]')),
              ],
              decoration: InputDecoration(
                  labelText: "whatever you want",
                  hintText: "whatever you want",
                  icon: Icon(Icons.phone_iphone)))

for earlier versions of 1.20

TextFormField(
    controller: _controller,
    keyboardType: TextInputType.number,
    inputFormatters: <TextInputFormatter>[
        WhitelistingTextInputFormatter.digitsOnly
    ],
    decoration: InputDecoration(
        labelText:"whatever you want", 
        hintText: "whatever you want",
        icon: Icon(Icons.phone_iphone)
    )
)

onclick on a image to navigate to another page using Javascript

Because it makes these things so easy, you could consider using a JavaScript library like jQuery to do this:

<script>
    $(document).ready(function() {
        $('img.thumbnail').click(function() {
            window.location.href = this.id + '.html';
        });
    });
</script>

Basically, it attaches an onClick event to all images with class thumbnail to redirect to the corresponding HTML page (id + .html). Then you only need the images in your HTML (without the a elements), like this:

<img src="bottle.jpg" alt="bottle" class="thumbnail" id="bottle" />
<img src="glass.jpg" alt="glass" class="thumbnail" id="glass" />

REST response code for invalid data

400 is the best choice in both cases. If you want to further clarify the error you can either change the Reason Phrase or include a body to explain the error.

412 - Precondition failed is used for conditional requests when using last-modified date and ETags.

403 - Forbidden is used when the server wishes to prevent access to a resource.

The only other choice that is possible is 422 - Unprocessable entity.

using BETWEEN in WHERE condition

You might also encounter an error message. "Operand type clash: date is incompatible with int.

Use single quotes around the dates. E.g.: $this->db->where("$accommodation BETWEEN '$minvalue' AND '$maxvalue'");

Android studio- "SDK tools directory is missing"

It was mentioned before but to be clear, It probably is due to your internet connection.

In my case it was that in my job I am behind a proxy, that means I should set a proxy in android studio for it to be able to download all SDK files.

You can set a proxy in the Android Studio Settings under Appearance & Behavior > System Settings > HTTP Proxy as stated here: https://developer.android.com/studio/intro/studio-config#proxy

Test de proxy (there's a button for that). Close Android Studio. Reopen Android Studio, and it should be able to download all SDK files.

Mock HttpContext.Current in Test Init Method

Below Test Init will also do the job.

[TestInitialize]
public void TestInit()
{
  HttpContext.Current = new HttpContext(new HttpRequest(null, "http://tempuri.org", null), new HttpResponse(null));
  YourControllerToBeTestedController = GetYourToBeTestedController();
}

What does the Ellipsis object do?

Summing up what others have said, as of Python 3, Ellipsis is essentially another singleton constant similar to None, but without a particular intended use. Existing uses include:

In slice syntax to represent the full slice in remaining dimensions
In type hinting to indicate only part of a type(Callable[..., int] or Tuple[str, ...])
In type stub files to indicate there is a default value without specifying it

Possible uses could include:

As a default value for places where None is a valid option
As the content for a function you haven't implemented yet

Run a Java Application as a Service on Linux

Im having Netty java application and I want to run it as a service with systemd. Unfortunately application stops no matter of what Type I'm using. At the end I've wrapped java start in screen. Here are the config files:

service

[Unit]
Description=Netty service
After=network.target
[Service]
User=user
Type=forking
WorkingDirectory=/home/user/app
ExecStart=/home/user/app/start.sh
TimeoutStopSec=10
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target

start

#!/bin/sh
/usr/bin/screen -L -dmS netty_app java -cp app.jar classPath

from that point you can use systemctl [start|stop|status] service.

How do I move to end of line in Vim?

If your current line wraps around the visible screen onto the next line, you can use g$ to get to the end of the screen line.

What is the difference between MySQL, MySQLi and PDO?

Specifically, the MySQLi extension provides the following extremely useful benefits over the old MySQL extension..

OOP Interface (in addition to procedural) Prepared Statement Support Transaction + Stored Procedure Support Nicer Syntax Speed Improvements Enhanced Debugging

PDO Extension

PHP Data Objects extension is a Database Abstraction Layer. Specifically, this is not a MySQL interface, as it provides drivers for many database engines (of course including MYSQL).

PDO aims to provide a consistent API that means when a database engine is changed, the code changes to reflect this should be minimal. When using PDO, your code will normally "just work" across many database engines, simply by changing the driver you're using.

In addition to being cross-database compatible, PDO also supports prepared statements, stored procedures and more, whilst using the MySQL Driver.

What is the difference between Cloud, Grid and Cluster?

Cloud is a marketing term, with the bare minimum feature relating to fast automated provisioning of new servers. HA, utility billing, etc are all features people can lump on top to define it to their own liking.

Grid [Computing] is an extension of clusters where multiple loosely coupled systems are used to solve a single problem. They tend to be multi-tenant, sharing some likeness to Clouds, but tend to rely heavily upon custom frameworks that manage the interop between grid nodes.

Cluster hosting is a specialization of clusters where a load balancer is used to direct incoming traffic to one of many worker nodes. It predates grid computing and doesn't rely on a homogenous abstraction of the underlying nodes as much as Grid computing. A web farm tends to have very specialized machines dedicated to each component type and is far more optimized for that specific task.

For pure hosting, Grid computing is the wrong tool. If you have no idea what your traffic shape is, then a Cloud would be useful. For predictable usage that changes at a reasonable pace, then a traditional cluster is fine and the most efficient.

How to read multiple text files into a single RDD?

rdd = textFile('/data/{1.txt,2.txt}')

Best way to overlay an ESRI shapefile on google maps?

I like using (open source and gui friendly) Quantum GIS to convert the shapefile to kml.

Google Maps API supports only a subset of the KML standard. One limitation is file size.

To reduce your file size, you can Quantum GIS's "simplify geometries" function. This "smooths" polygons.

Then you can select your layer and do a "save as kml" on it.

If you need to process a bunch of files, the process can be batched with Quantum GIS's ogr2ogr command from osgeo4w shell.

Finally, I recommend zipping your kml (with your favorite compression program) for reduced file size and saving it as kmz.

Mobile overflow:scroll and overflow-scrolling: touch // prevent viewport "bounce"

There's a great blog post on this here:

http://www.kylejlarson.com/blog/2011/fixed-elements-and-scrolling-divs-in-ios-5/

Along with a demo here:

http://www.kylejlarson.com/files/iosdemo/

In summary, you can use the following on a div containing your main content:

.scrollable {
    position: absolute;
    top: 50px;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: scroll;
    -webkit-overflow-scrolling: touch;
}

The problem I think you're describing is when you try to scroll up within a div that is already at the top - it then scrolls up the page instead of up the div and causes a bounce effect at the top of the page. I think your question is asking how to get rid of this?

In order to fix this, the author suggests that you use ScrollFix to auto increase the height of scrollable divs.

It's also worth noting that you can use the following to prevent the user from scrolling up e.g. in a navigation element:

document.addEventListener('touchmove', function(event) {
   if(event.target.parentNode.className.indexOf('noBounce') != -1 
|| event.target.className.indexOf('noBounce') != -1 ) {
    event.preventDefault(); }
}, false);

Unfortunately there are still some issues with ScrollFix (e.g. when using form fields), but the issues list on ScrollFix is a good place to look for alternatives. Some alternative approaches are discussed in this issue.

Other alternatives, also mentioned in the blog post, are Scrollability and iScroll

django - get() returned more than one topic

Don't :-

xyz = Blogs.objects.get(user_id=id)

Use:-

xyz = Blogs.objects.all().filter(user_id=id)

Implement paging (skip / take) functionality with this query

The fix is to modify your EDMX file, using the XML editor, and change the value of ProviderManifestToken from 2012 to 2008. I found that on line 7 in my EDMX file. After saving that change, the paging SQL will be generated using the “old”, SQL Server 2008 compatible syntax.

My apologies for posting an answer on this very old thread. Posting it for the people like me, I solved this issue today.

How to remove gem from Ruby on Rails application?

You are using some sort of revision control, right? Then it should be quite simple to restore to the commit before you added the gem, or revert the one where you added it if you have several revisions after that you wish to keep.

Get request URL in JSP which is forwarded by Servlet

Also you could use

${pageContext.request.requestURI}

Using NSPredicate to filter an NSArray based on NSDictionary keys

With Swift 3, when you want to filter an array of dictionaries with a predicate based on dictionary keys and values, you may choose one of the following patterns.

#1. Using `NSPredicate` `init(format:arguments:)` initializer

If you come from Objective-C, init(format:arguments:) offers a key-value coding style to evaluate your predicate.

Usage:

import Foundation

let array = [["key1": "value1", "key2": "value2"], ["key1": "value3"], ["key3": "value4"]]

let predicate = NSPredicate(format: "key1 == %@", "value1")
//let predicate = NSPredicate(format: "self['key1'] == %@", "value1") // also works
let filteredArray = array.filter(predicate.evaluate)

print(filteredArray) // prints: [["key2": "value2", "key1": "value1"]]

#2. Using `NSPredicate` `init(block:)` initializer

As an alternative if you prefer strongly typed APIs over stringly typed APIs, you can use init(block:) initializer.

Usage:

import Foundation

let array = [["key1": "value1", "key2": "value2"], ["key1": "value3"], ["key3": "value4"]]

let dictPredicate = NSPredicate(block: { (obj, _) in
    guard let dict = obj as? [String: String], let value = dict["key1"] else { return false }
    return value == "value1"
})

let filteredArray = array.filter(dictPredicate.evaluate)
print(filteredArray) // prints: [["key2": "value2", "key1": "value1"]]

How to get unique device hardware id in Android?

Update: 19 -11-2019

The below answer is no more relevant to present day.

So for any one looking for answers you should look at the documentation linked below

https://developer.android.com/training/articles/user-data-ids

Old Answer - Not relevant now. You check this blog in the link below

http://android-developers.blogspot.in/2011/03/identifying-app-installations.html

ANDROID_ID

import android.provider.Settings.Secure;

private String android_id = Secure.getString(getContext().getContentResolver(),
                                                    Secure.ANDROID_ID);

The above is from the link @ Is there a unique Android device ID?

More specifically, Settings.Secure.ANDROID_ID. This is a 64-bit quantity that is generated and stored when the device first boots. It is reset when the device is wiped.

ANDROID_ID seems a good choice for a unique device identifier. There are downsides: First, it is not 100% reliable on releases of Android prior to 2.2 (“Froyo”). Also, there has been at least one widely-observed bug in a popular handset from a major manufacturer, where every instance has the same ANDROID_ID.

The below solution is not a good one coz the value survives device wipes (“Factory resets”) and thus you could end up making a nasty mistake when one of your customers wipes their device and passes it on to another person.

You get the imei number of the device using the below

  TelephonyManager telephonyManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
  telephonyManager.getDeviceId();

http://developer.android.com/reference/android/telephony/TelephonyManager.html#getDeviceId%28%29

Add this is manifest

<uses-permission android:name="android.permission.READ_PHONE_STATE"/>

scrollTop animation without jquery

HTML:

<button onclick="scrollToTop(1000);"></button>

1# JavaScript (linear):

function scrollToTop (duration) {
    // cancel if already on top
    if (document.scrollingElement.scrollTop === 0) return;

    const totalScrollDistance = document.scrollingElement.scrollTop;
    let scrollY = totalScrollDistance, oldTimestamp = null;

    function step (newTimestamp) {
        if (oldTimestamp !== null) {
            // if duration is 0 scrollY will be -Infinity
            scrollY -= totalScrollDistance * (newTimestamp - oldTimestamp) / duration;
            if (scrollY <= 0) return document.scrollingElement.scrollTop = 0;
            document.scrollingElement.scrollTop = scrollY;
        }
        oldTimestamp = newTimestamp;
        window.requestAnimationFrame(step);
    }
    window.requestAnimationFrame(step);
}

2# JavaScript (ease in and out):

function scrollToTop (duration) {
    // cancel if already on top
    if (document.scrollingElement.scrollTop === 0) return;

    const cosParameter = document.scrollingElement.scrollTop / 2;
    let scrollCount = 0, oldTimestamp = null;

    function step (newTimestamp) {
        if (oldTimestamp !== null) {
            // if duration is 0 scrollCount will be Infinity
            scrollCount += Math.PI * (newTimestamp - oldTimestamp) / duration;
            if (scrollCount >= Math.PI) return document.scrollingElement.scrollTop = 0;
            document.scrollingElement.scrollTop = cosParameter + cosParameter * Math.cos(scrollCount);
        }
        oldTimestamp = newTimestamp;
        window.requestAnimationFrame(step);
    }
    window.requestAnimationFrame(step);
}
/* 
  Explanation:
  - pi is the length/end point of the cosinus intervall (see below)
  - newTimestamp indicates the current time when callbacks queued by requestAnimationFrame begin to fire.
    (for more information see https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame)
  - newTimestamp - oldTimestamp equals the delta time

    a * cos (bx + c) + d                        | c translates along the x axis = 0
  = a * cos (bx) + d                            | d translates along the y axis = 1 -> only positive y values
  = a * cos (bx) + 1                            | a stretches along the y axis = cosParameter = window.scrollY / 2
  = cosParameter + cosParameter * (cos bx)  | b stretches along the x axis = scrollCount = Math.PI / (scrollDuration / (newTimestamp - oldTimestamp))
  = cosParameter + cosParameter * (cos scrollCount * x)
*/

Note:

Duration in milliseconds (1000ms = 1s)
Second script uses the cos function. Example curve:

enter image description here

3# Simple scrolling library on Github

Angular no provider for NameService

Shockingly, the syntax has changed yet again in the latest version of Angular :-) From the Angular 6 docs:

Beginning with Angular 6.0, the preferred way to create a singleton services is to specify on the service that it should be provided in the application root. This is done by setting providedIn to root on the service's @Injectable decorator:

src/app/user.service.0.ts

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root',
})
export class UserService {
}

SQL Update to the SUM of its joined values

How about this:

UPDATE p
SET p.extrasPrice = t.sumPrice
FROM BookingPitches AS p
INNER JOIN
    (
        SELECT PitchID, SUM(Price) sumPrice
        FROM BookingPitchExtras
        WHERE [required] = 1
        GROUP BY PitchID 
    ) t
    ON t.PitchID = p.ID
WHERE p.bookingID = 1

Is it possible to specify a different ssh port when using rsync?

when you need to send files through a specific SSH port:

rsync -azP -e "ssh -p PORT_NUMBER" source destination

example

rsync -azP -e "ssh -p 2121" /path/to/files/source user@remoteip:/path/to/files/destination

How to merge 2 List<T> and removing duplicate values from it in C#

why not simply eg

var newList = list1.Union(list2)/*.Distinct()*//*.ToList()*/;

oh ... according to the documentation you can leave out the .Distinct()

This method excludes duplicates from the return set

Changing color of Twitter bootstrap Nav-Pills

Bootstrap 4.x Solution

.nav-pills .nav-link.active {
    background-color: #ff0000 !important;
}

How do I run Visual Studio as an administrator by default?

Right click on icon --> Properties --> Advanced --> Check checkbox run as Administrator and everytime it will open under Admin Mode (Same for Windows 8)

Find number of decimal places in decimal value regardless of culture

As a decimal extension method that takes into account:

Different cultures
Whole numbers
Negative numbers
Trailing set zeros on the decimal place (e.g. 1.2300M will return 2 not 4)

public static class DecimalExtensions
{
    public static int GetNumberDecimalPlaces(this decimal source)
    {
        var parts = source.ToString(CultureInfo.InvariantCulture).Split('.');

        if (parts.Length < 2)
            return 0;

        return parts[1].TrimEnd('0').Length;
    }
}

Reading a JSP variable from JavaScript

The cleanest way, as far as I know:

add your JSP variable to an HTML element's data-* attribute
then read this value via Javascript when required

My opinion regarding the current solutions on this SO page: reading "directly" JSP values using java scriplet inside actual javascript code is probably the most disgusting thing you could do. Makes me wanna puke. haha. Seriously, try to not do it.

The HTML part without JSP:

<body data-customvalueone="1st Interpreted Jsp Value" data-customvaluetwo="another Interpreted Jsp Value">
    Here is your regular page main content
</body>

The HTML part when using JSP:

<body data-customvalueone="${beanName.attrName}" data-customvaluetwo="${beanName.scndAttrName}">
    Here is your regular page main content
</body>

The javascript part (using jQuery for simplicity):

<script type="text/JavaScript" src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.js"></script>
<script type="text/javascript">
    jQuery(function(){
        var valuePassedFromJSP = $("body").attr("data-customvalueone");
        var anotherValuePassedFromJSP = $("body").attr("data-customvaluetwo");

        alert(valuePassedFromJSP + " and " + anotherValuePassedFromJSP + " are the values passed from your JSP page");
});
</script>

And here is the jsFiddle to see this in action http://jsfiddle.net/6wEYw/2/

Resources:

HTML 5 data-* attribute: https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes
Include javascript into html file Include JavaScript file in HTML won't work as <script .... />
CSS selectors (also usable when selecting via jQuery) https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Getting_started/Selectors
Get an HTML element attribute via jQuery http://api.jquery.com/attr/

What is the best way to prevent session hijacking?

There are many ways to create protection against session hijack, however all of them are either reducing user satisfaction or are not secure.

IP and/or X-FORWARDED-FOR checks. These work, and are pretty secure... but imagine the pain of users. They come to an office with WiFi, they get new IP address and lose the session. Got to log-in again.
User Agent checks. Same as above, new version of browser is out, and you lose a session. Additionally, these are really easy to "hack". It's trivial for hackers to send fake UA strings.
localStorage token. On log-on generate a token, store it in browser storage and store it to encrypted cookie (encrypted on server-side). This has no side-effects for user (localStorage persists through browser upgrades). It's not as secure - as it's just security through obscurity. Additionally you could add some logic (encryption/decryption) to JS to further obscure it.
Cookie reissuing. This is probably the right way to do it. The trick is to only allow one client to use a cookie at a time. So, active user will have cookie re-issued every hour or less. Old cookie is invalidated if new one is issued. Hacks are still possible, but much harder to do - either hacker or valid user will get access rejected.

How can I stop Chrome from going into debug mode?

If you were unfamiliar with the tools, it was likely that at some point while in the debugger you toggled a setting that was causing the debugger to stop the application.

I suggest you "Disable all break points":

Source:

https://javascript.info/debugging-chrome

why is plotting with Matplotlib so slow?

First off, (though this won't change the performance at all) consider cleaning up your code, similar to this:

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

x = np.arange(0, 2*np.pi, 0.01)
y = np.sin(x)

fig, axes = plt.subplots(nrows=6)
styles = ['r-', 'g-', 'y-', 'm-', 'k-', 'c-']
lines = [ax.plot(x, y, style)[0] for ax, style in zip(axes, styles)]

fig.show()

tstart = time.time()
for i in xrange(1, 20):
    for j, line in enumerate(lines, start=1):
        line.set_ydata(np.sin(j*x + i/10.0))
    fig.canvas.draw()

print 'FPS:' , 20/(time.time()-tstart)

With the above example, I get around 10fps.

Just a quick note, depending on your exact use case, matplotlib may not be a great choice. It's oriented towards publication-quality figures, not real-time display.

However, there are a lot of things you can do to speed this example up.

There are two main reasons why this is as slow as it is.

1) Calling fig.canvas.draw() redraws everything. It's your bottleneck. In your case, you don't need to re-draw things like the axes boundaries, tick labels, etc.

2) In your case, there are a lot of subplots with a lot of tick labels. These take a long time to draw.

Both these can be fixed by using blitting.

To do blitting efficiently, you'll have to use backend-specific code. In practice, if you're really worried about smooth animations, you're usually embedding matplotlib plots in some sort of gui toolkit, anyway, so this isn't much of an issue.

However, without knowing a bit more about what you're doing, I can't help you there.

Nonetheless, there is a gui-neutral way of doing it that is still reasonably fast.

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

x = np.arange(0, 2*np.pi, 0.1)
y = np.sin(x)

fig, axes = plt.subplots(nrows=6)

fig.show()

# We need to draw the canvas before we start animating...
fig.canvas.draw()

styles = ['r-', 'g-', 'y-', 'm-', 'k-', 'c-']
def plot(ax, style):
    return ax.plot(x, y, style, animated=True)[0]
lines = [plot(ax, style) for ax, style in zip(axes, styles)]

# Let's capture the background of the figure
backgrounds = [fig.canvas.copy_from_bbox(ax.bbox) for ax in axes]

tstart = time.time()
for i in xrange(1, 2000):
    items = enumerate(zip(lines, axes, backgrounds), start=1)
    for j, (line, ax, background) in items:
        fig.canvas.restore_region(background)
        line.set_ydata(np.sin(j*x + i/10.0))
        ax.draw_artist(line)
        fig.canvas.blit(ax.bbox)

print 'FPS:' , 2000/(time.time()-tstart)

This gives me ~200fps.

To make this a bit more convenient, there's an animations module in recent versions of matplotlib.

As an example:

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

x = np.arange(0, 2*np.pi, 0.1)
y = np.sin(x)

fig, axes = plt.subplots(nrows=6)

styles = ['r-', 'g-', 'y-', 'm-', 'k-', 'c-']
def plot(ax, style):
    return ax.plot(x, y, style, animated=True)[0]
lines = [plot(ax, style) for ax, style in zip(axes, styles)]

def animate(i):
    for j, line in enumerate(lines, start=1):
        line.set_ydata(np.sin(j*x + i/10.0))
    return lines

# We'd normally specify a reasonable "interval" here...
ani = animation.FuncAnimation(fig, animate, xrange(1, 200), 
                              interval=0, blit=True)
plt.show()

Bash loop ping successful

You don't need to use echo or grep. You could do this:

ping -oc 100000 8.8.8.8 > /dev/null && say "up" || say "down"

How to open an existing project in Eclipse?

I also have just faced with this problem that how to open existing file. And none of answers was helpful. That's why I tried by myself.

Direction: File -> Open file -> Workspace (with you had chosen first in creating your project) -> Package (which you already created your project in) -> src (source file) -> Created package ->

And now your searching project's nodepad format. I hope it would be helpful. If any mistake here, sorry beforehand.

What does the CSS rule "clear: both" do?

I won't be explaining how the floats work here (in detail), as this question generally focuses on Why use clear: both; OR what does clear: both; exactly do...

I'll keep this answer simple, and to the point, and will explain to you graphically why clear: both; is required or what it does...

Generally designers float the elements, left or to the right, which creates an empty space on the other side which allows other elements to take up the remaining space.

Why do they float elements?

Elements are floated when the designer needs 2 block level elements side by side. For example say we want to design a basic website which has a layout like below...

enter image description here

Live Example of the demo image.

Code For Demo

_x000D_

/*  CSS:  */_x000D_
_x000D_
* { /* Not related to floats / clear both, used it for demo purpose only */_x000D_
    box-sizing: border-box;_x000D_
    -moz-box-sizing: border-box;_x000D_
    -webkit-box-sizing: border-box;_x000D_
}_x000D_
_x000D_
header, footer {_x000D_
    border: 5px solid #000;_x000D_
    height: 100px;_x000D_
}_x000D_
_x000D_
aside {_x000D_
    float: left;_x000D_
    width: 30%;_x000D_
    border: 5px solid #000;_x000D_
    height: 300px;_x000D_
}_x000D_
_x000D_
section {_x000D_
    float: left;_x000D_
    width: 70%;_x000D_
    border: 5px solid #000;_x000D_
    height: 300px;_x000D_
}_x000D_
_x000D_
.clear {_x000D_
    clear: both;_x000D_
}

_x000D_

<!-- HTML -->_x000D_
<header>_x000D_
    Header_x000D_
</header>_x000D_
<aside>_x000D_
    Aside (Floated Left)_x000D_
</aside>_x000D_
<section>_x000D_
    Content (Floated Left, Can Be Floated To Right As Well)_x000D_
</section>_x000D_
<!-- Clearing Floating Elements-->_x000D_
<div class="clear"></div>_x000D_
<footer>_x000D_
    Footer_x000D_
</footer>

_x000D_

Note: You might have to add header, footer, aside, section (and other HTML5 elements) as display: block; in your stylesheet for explicitly mentioning that the elements are block level elements.

Explanation:

I have a basic layout, 1 header, 1 side bar, 1 content area and 1 footer.

No floats for header, next comes the aside tag which I'll be using for my website sidebar, so I'll be floating the element to left.

Note: By default, block level element takes up document 100% width, but when floated left or right, it will resize according to the content it holds.

So as you note, the left floated div leaves the space to its right unused, which will allow the div after it to shift in the remaining space.

Ok, so this is how block level elements behave when floated left or right, so now why is clear: both; required and why?

So if you note in the layout demo - in case you forgot, here it is..

I am using a class called .clear and it holds a property called clear with a value of both. So lets see why it needs both.

I've floated aside and section elements to the left, so assume a scenario, where we have a pool, where header is solid land, aside and section are floating in the pool and footer is solid land again, something like this..

Floated View

So the blue water has no idea what the area of the floated elements are, they can be bigger than the pool or smaller, so here comes a common issue which troubles 90% of CSS beginners: why the background of a container element is not stretched when it holds floated elements. It's because the container element is a POOL here and the POOL has no idea how many objects are floating, or what the length or breadth of the floated elements are, so it simply won't stretch.

(Refer ^[Clearfix] section of this answer for neat way to do this. I am using an empty div example intentionally for explanation purpose)

I've provided 3 examples above, 1st is the normal document flow where red background will just render as expected since the container doesn't hold any floated objects.

In the second example, when the object is floated to left, the container element (POOL) won't know the dimensions of the floated elements and hence it won't stretch to the floated elements height.

enter image description here

After using clear: both;, the container element will be stretched to its floated element dimensions.

enter image description here

Another reason the clear: both; is used is to prevent the element to shift up in the remaining space.

Say you want 2 elements side by side and another element below them... So you will float 2 elements to left and you want the other below them.

1st Example

enter image description here

2nd Example

enter image description here

Last but not the least, the footer tag will be rendered after floated elements as I've used the clear class before declaring my footer tags, which ensures that all the floated elements (left/right) are cleared up to that point.

Clearfix

Coming to clearfix which is related to floats. As already specified by @Elky, the way we are clearing these floats is not a clean way to do it as we are using an empty div element which is not a div element is meant for. Hence here comes the clearfix.

Think of it as a virtual element which will create an empty element for you before your parent element ends. This will self clear your wrapper element holding floated elements. This element won't exist in your DOM literally but will do the job.

To self clear any wrapper element having floated elements, we can use

.wrapper_having_floated_elements:after {  /* Imaginary class name */
  content: "";
  clear: both;
  display: table;
}

Note the :after pseudo element used by me for that class. That will create a virtual element for the wrapper element just before it closes itself. If we look in the dom you can see how it shows up in the Document tree.

So if you see, it is rendered after the floated child div where we clear the floats which is nothing but equivalent to have an empty div element with clear: both; property which we are using for this too. Now why display: table; and content is out of this answers scope but you can learn more about pseudo element here.

Note that this will also work in IE8 as IE8 supports :after pseudo.

Original Answer:

Most of the developers float their content left or right on their pages, probably divs holding logo, sidebar, content etc., these divs are floated left or right, leaving the rest of the space unused and hence if you place other containers, it will float too in the remaining space, so in order to prevent that clear: both; is used, it clears all the elements floated left or right.

Demonstration:

------------------ ----------------------------------
div1(Floated Left) Other div takes up the space here
------------------ ----------------------------------

Now what if you want to make the other div render below div1, so you'll use clear: both; so it will ensure you clear all floats, left or right

------------------
div1(Floated Left)
------------------
<div style="clear: both;"><!--This <div> acts as a separator--></div>
----------------------------------
Other div renders here now
----------------------------------

What is best tool to compare two SQL Server databases (schema and data)?

We are using an inhouse developed solution that is basicly a procedure with arguments of what you want included in the comparision (SP's, Full SP code, table structure, defaults, indices, triggers.. etc)

Depending on your needs and budget, it might be a good way to go for you as well.

It is quite easily developed as well, then we just redirect output of procedure to textfiles and do text comparisions between the files.

One good thing about it is that its possible to save the output in source control.

How to get the employees with their managers

You could have just changed your query to:

SELECT ename, empno, (SELECT ename FROM EMP WHERE empno = e.mgr)AS MANAGER, mgr 
from emp e 
order by empno;

This would tell the engine that for the inner emp table, empno should be matched with mgr column from the outer table. enter image description here

How to pass arguments from command line to gradle

There's a great example here:

https://kb.novaordis.com/index.php/Gradle_Pass_Configuration_on_Command_Line

Which details that you can pass parameters and then provide a default in an ext variable like so:

gradle -Dmy_app.color=blue

and then reference in Gradle as:

ext {
   color = System.getProperty("my_app.color", "red");
}

And then anywhere in your build script you can reference it as course anywhere you can reference it as project.ext.color

More tips here: https://kb.novaordis.com/index.php/Gradle_Variables_and_Properties

PHP Unset Session Variable

If you completely want to clear the session you can use this:

session_unset();
session_destroy();

Actually both are not neccessary but it does not hurt.

If you want to clear only a specific part I think you need this:

unset($_SESSION['Products']);
//or
$_SESSION['Products'] = "";

depending on what you need.

Declaration of Methods should be Compatible with Parent Methods in PHP

This message means that there are certain possible method calls which may fail at run-time. Suppose you have

class A { public function foo($a = 1) {;}}
class B extends A { public function foo($a) {;}}
function bar(A $a) {$a->foo();}

The compiler only checks the call $a->foo() against the requirements of A::foo() which requires no parameters. $a may however be an object of class B which requires a parameter and so the call would fail at runtime.

This however can never fail and does not trigger the error

class A { public function foo($a) {;}}
class B extends A { public function foo($a = 1) {;}}
function bar(A $a) {$a->foo();}

So no method may have more required parameters than its parent method.

The same message is also generated when type hints do not match, but in this case PHP is even more restrictive. This gives an error:

class A { public function foo(StdClass $a) {;}}
class B extends A { public function foo($a) {;}}

as does this:

class A { public function foo($a) {;}}
class B extends A { public function foo(StdClass $a) {;}}

That seems more restrictive than it needs to be and I assume is due to internals.

Visibility differences cause a different error, but for the same basic reason. No method can be less visible than its parent method.

Write a file on iOS

Your code is working at my end, i have just tested it. Where are you checking your changes? Use Documents directory path. To get path -

NSLog(@"%@",documentsDirectory);

and copy path from console and then open finder and press Cmd+shift+g and paste path here and then open your file

How do I solve this "Cannot read property 'appendChild' of null" error?

For all those facing a similar issue, I came across this same issue when i was trying to run a particular code snippet, shown below.

<html>
    <head>
        <script>
                var div, container = document.getElementById("container")
                for(var i=0;i<5;i++){
                    div = document.createElement("div");
                    div.onclick = function() { 
                        alert("This is a box #"+i);
                    };
                    container.appendChild(div);
                }
            </script>

    </head>
    <body>
        <div id="container"></div>
    </body>
 </html>

https://codepen.io/pcwanderer/pen/MMEREr

Looking at the error in the console for the above code.

Since the document.getElementById is returning a null and as null does not have a attribute named appendChild, therefore a error is thrown. To solve the issue see the code below.

<html>
    <head>
        <style>
        #container{
            height: 200px;
            width: 700px;
            background-color: red;
            margin: 10px;
        }


        div{
            height: 100px;
            width: 100px;
            background-color: purple;
            margin: 20px;
            display: inline-block;
        }
        </style>
    </head>
    <body>
        <div id="container"></div>
        <script>
                var div, container = document.getElementById("container")
                for(let i=0;i<5;i++){
                    div = document.createElement("div");
                    div.onclick = function() { 
                        alert("This is a box #"+i);
                    };
                    container.appendChild(div);
                }
            </script>
    </body>
</html>

https://codepen.io/pcwanderer/pen/pXWBQL

I hope this helps. :)

Find the version of an installed npm package

npm list package-name gives the currently installed version

How To fix white screen on app Start up?

Try the following code:

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowIsTranslucent">true</item>
</style>

This code works for me and will work on all Android devices.

Redis command to get all available keys?

SCAN doesn't require the client to load all the keys into memory like KEYS does. SCAN gives you an iterator you can use. I had a 1B records in my redis and I could never get enough memory to return all the keys at once.

Here is a python snippet to get all keys from the store matching a pattern and delete them:

import redis
r = redis.StrictRedis(host='localhost', port=6379, db=0)
for key in r.scan_iter("key_pattern*"):
    print key

Adding items in a Listbox with multiple columns

select propety

Row Source Type => Value List

Code :

ListbName.ColumnCount=2

ListbName.AddItem "value column1;value column2"

Failed to authenticate on SMTP server error using gmail

If you still get this error when sending email: "Failed to authenticate on SMTP server with username "[email protected]" using 3 possible authenticators"

You may try one of these methods:

Go to https://accounts.google.com/UnlockCaptcha, click continue and unlock your account for access through other media/sites.

Use double quote for your password: like - "Abc@%$67eSDu"

Google access token expiration time

Have a look at: https://developers.google.com/accounts/docs/OAuth2UserAgent#handlingtheresponse

It says:

Other parameters included in the response include expires_in and token_type. These parameters describe the lifetime of the token in seconds...

Elegant ways to support equivalence ("equality") in Python classes

The 'is' test will test for identity using the builtin 'id()' function which essentially returns the memory address of the object and therefore isn't overloadable.

However in the case of testing the equality of a class you probably want to be a little bit more strict about your tests and only compare the data attributes in your class:

import types

class ComparesNicely(object):

    def __eq__(self, other):
        for key, value in self.__dict__.iteritems():
            if (isinstance(value, types.FunctionType) or 
                    key.startswith("__")):
                continue

            if key not in other.__dict__:
                return False

            if other.__dict__[key] != value:
                return False

         return True

This code will only compare non function data members of your class as well as skipping anything private which is generally what you want. In the case of Plain Old Python Objects I have a base class which implements __init__, __str__, __repr__ and __eq__ so my POPO objects don't carry the burden of all that extra (and in most cases identical) logic.

Unicode, UTF, ASCII, ANSI format differences

Going down your list:

"Unicode" isn't an encoding, although unfortunately, a lot of documentation imprecisely uses it to refer to whichever Unicode encoding that particular system uses by default. On Windows and Java, this often means UTF-16; in many other places, it means UTF-8. Properly, Unicode refers to the abstract character set itself, not to any particular encoding.
UTF-16: 2 bytes per "code unit". This is the native format of strings in .NET, and generally in Windows and Java. Values outside the Basic Multilingual Plane (BMP) are encoded as surrogate pairs. These used to be relatively rarely used, but now many consumer applications will need to be aware of non-BMP characters in order to support emojis.
UTF-8: Variable length encoding, 1-4 bytes per code point. ASCII values are encoded as ASCII using 1 byte.
UTF-7: Usually used for mail encoding. Chances are if you think you need it and you're not doing mail, you're wrong. (That's just my experience of people posting in newsgroups etc - outside mail, it's really not widely used at all.)
UTF-32: Fixed width encoding using 4 bytes per code point. This isn't very efficient, but makes life easier outside the BMP. I have a .NET Utf32String class as part of my MiscUtil library, should you ever want it. (It's not been very thoroughly tested, mind you.)
ASCII: Single byte encoding only using the bottom 7 bits. (Unicode code points 0-127.) No accents etc.
ANSI: There's no one fixed ANSI encoding - there are lots of them. Usually when people say "ANSI" they mean "the default locale/codepage for my system" which is obtained via Encoding.Default, and is often Windows-1252 but can be other locales.

There's more on my Unicode page and tips for debugging Unicode problems.

The other big resource of code is unicode.org which contains more information than you'll ever be able to work your way through - possibly the most useful bit is the code charts.

Cannot resolve symbol 'AppCompatActivity'

This is the lifesaver code I found somewhere(sorry don't remember the origin). Add it to build.gradle (Module:app). You can replace the version to the relevant.

configurations.all {

    resolutionStrategy.eachDependency { DependencyResolveDetails details -
        def requested = details.requested

 if (requested.group == 'com.android.support') {

            if (!requested.name.startsWith("multidex")) {
                details.useVersion '27.1.1'
            }
        } else if (requested.group == "com.google.android.gms") {
            details.useVersion '15.0.0'
        } else if (requested.group == "com.google.firebase") {
            details.useVersion '15.0.0'
        }
    }
}

How do I serialize an object and save it to a file in Android?

I've tried this 2 options (read/write), with plain objects, array of objects (150 objects), Map:

Option1:

FileOutputStream fos = context.openFileOutput(fileName, Context.MODE_PRIVATE);
ObjectOutputStream os = new ObjectOutputStream(fos);
os.writeObject(this);
os.close();

Option2:

SharedPreferences mPrefs=app.getSharedPreferences(app.getApplicationInfo().name, Context.MODE_PRIVATE);
SharedPreferences.Editor ed=mPrefs.edit();
Gson gson = new Gson(); 
ed.putString("myObjectKey", gson.toJson(objectToSave));
ed.commit();

Option 2 is twice quicker than option 1

The option 2 inconvenience is that you have to make specific code for read:

Gson gson = new Gson();
JsonParser parser=new JsonParser();
//object arr example
JsonArray arr=parser.parse(mPrefs.getString("myArrKey", null)).getAsJsonArray();
events=new Event[arr.size()];
int i=0;
for (JsonElement jsonElement : arr)
    events[i++]=gson.fromJson(jsonElement, Event.class);
//Object example
pagination=gson.fromJson(parser.parse(jsonPagination).getAsJsonObject(), Pagination.class);

How to assign Php variable value to Javascript variable?

Put quotes around the <?php echo $cname; ?> to make sure Javascript accepts it as a string, also consider escaping.

Why .NET String is immutable?

You never have to defensively copy immutable data. Despite the fact that you need to copy it to mutate it, often the ability to freely alias and never have to worry about unintended consequences of this aliasing can lead to better performance because of the lack of defensive copying.

How to change ViewPager's page?

slide to right

viewPager.arrowScroll(View.FOCUS_RIGHT);

slide to left

viewPager.arrowScroll(View.FOCUS_LEFT);

How to prune local tracking branches that do not exist on remote anymore

Based on the answers above I'm using this shorter one liner:

git remote prune origin | awk 'BEGIN{FS="origin/"};/pruned/{print $2}' | xargs -r git branch -d

Also, if you already pruned and have local dangling branches, then this will clean them up:

git branch -vv | awk '/^ .*gone/{print $1}' | xargs -r git branch -d

Uses of content-disposition in an HTTP response header

Refer to RFC 6266 (Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)) http://tools.ietf.org/html/rfc6266

How to change UINavigationBar background color from the AppDelegate

The colour code is the issue here. Instead of using 195/255, use 0.7647 or 195.f/255.f The problem is converting the float is not working properly. Try using exact float value.

Checking Date format from a string in C#

you can use DateTime.ParseExact with the format string

DateTime dt = DateTime.ParseExact(inputString, formatString, System.Globalization.CultureInfo.InvariantCulture);

Above will throw an exception if the given string not in given format.

use DateTime.TryParseExact if you don't need exception in case of format incorrect but you can check the return value of that method to identify whether parsing value success or not.

check Custom Date and Time Format Strings

Default password of mysql in ubuntu server 16.04

You can simply reset the root password by running the server with --skip-grant-tables and logging in without a password by running the following as root or with sudo:

service mysql stop
mysqld_safe --skip-grant-tables &
mysql -u root

mysql> use mysql;
mysql> update user set authentication_string=PASSWORD("YOUR-NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit

# service mysql stop
# service mysql start
$ mysql -u root -p

CakePHP 3.0 installation: intl extension missing from system

I'm using Mac OS High Sierra and none of these worked for me. But after searching a lot I found one that worked!

This may seem trivial, but in fact about 2 months ago some clever guys made changes in brew repository, so doing just: brew install php71-intl will show you error with message that such recipe doesn’t exists.

Fortunately, there is. There is temporary fix in another brew repo, so all you have to do is:

brew tap kyslik/homebrew-php
brew install kyslik/php/php71-intl

SOURCE: http://blastar.biz/2018/04/14/how-to-enable-php-intl-extension-for-php-7-1-using-xampp-on-macos-high-sierra/

How to comment/uncomment in HTML code

My view templates are generally .php files. This is what I would be using for now.

<?php // Some comment here ?>

The solution is quite similar to what @Robert suggested, works for me. Is not very clean I guess.

Git diff between current branch and master but not including unmerged master commits

git diff `git merge-base master branch`..branch

Merge base is the point where branch diverged from master.

Git diff supports a special syntax for this:

git diff master...branch

You must not swap the sides because then you would get the other branch. You want to know what changed in branch since it diverged from master, not the other way round.

Loosely related:

Note that .. and ... syntax does not have the same semantics as in other Git tools. It differs from the meaning specified in man gitrevisions.

Quoting man git-diff:

git diff [--options] <commit> <commit> [--] [<path>…]

This is to view the changes between two arbitrary <commit>.

git diff [--options] <commit>..<commit> [--] [<path>…]

This is synonymous to the previous form. If <commit> on one side is omitted, it will have the same effect as using HEAD instead.

git diff [--options] <commit>...<commit> [--] [<path>…]

This form is to view the changes on the branch containing and up to the second <commit>, starting at a common ancestor of both <commit>. "git diff A...B" is equivalent to "git diff $(git-merge-base A B) B". You can omit any one of <commit>, which has the same effect as using HEAD instead.

Just in case you are doing something exotic, it should be noted that all of the <commit> in the above description, except in the last two forms that use ".." notations, can be any <tree>.

For a more complete list of ways to spell <commit>, see "SPECIFYING REVISIONS" section in gitrevisions[7]. However, "diff" is about comparing two endpoints, not ranges, and the range notations ("<commit>..<commit>" and "<commit>...<commit>") do not mean a range as defined in the "SPECIFYING RANGES" section in gitrevisions[7].

Sending E-mail using C#

The .NET framework has some built-in classes which allows you to send e-mail via your app.

You should take a look in the System.Net.Mail namespace, where you'll find the MailMessage and SmtpClient classes. You can set the BodyFormat of the MailMessage class to MailFormat.Html.

It could also be helpfull if you make use of the AlternateViews property of the MailMessage class, so that you can provide a plain-text version of your mail, so that it can be read by clients that do not support HTML.

http://msdn.microsoft.com/en-us/library/system.net.mail.mailmessage.alternateviews.aspx

How to export a MySQL database to JSON?

THis is somthing that should be done in the application layer.

For example, in php it is a s simple as

Edit Added the db connection stuff. No external anything needed.

$sql = "select ...";
$db = new PDO ( "mysql:$dbname", $user, $password) ;
$stmt = $db->prepare($sql);
$stmt->execute();
$result = $stmt->fetchAll();

file_put_contents("output.txt", json_encode($result));

Java: Best way to iterate through a Collection (here ArrayList)

All of them have there own uses:

If you have an iterable and need to traverse unconditionally to all of them:

for (iterable_type iterable_element : collection)
If you have an iterable but need to conditionally traverse:

for (Iterator iterator = collection.iterator(); iterator.hasNext();)
If data-structure does not implement iterable:

for (int i = 0; i < collection.length; i++)

How to get current instance name from T-SQL

How about this:

EXECUTE xp_regread @rootkey='HKEY_LOCAL_MACHINE',
                   @key='SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQl',
                   @value_name='MSSQLSERVER'

This will get the instance name as well. null means default instance:

SELECT SERVERPROPERTY ('InstanceName')

http://technet.microsoft.com/en-us/library/ms174396.aspx

Add an object to an Array of a custom class

The array declaration should be:

Car[] garage = new Car[100];

You can also just assign directly:

garage[1] = new Car("Blue");

Effectively use async/await with ASP.NET Web API

You are not leveraging async / await effectively because the request thread will be blocked while executing the synchronous method ReturnAllCountries()

The thread that is assigned to handle a request will be idly waiting while ReturnAllCountries() does it's work.

If you can implement ReturnAllCountries() to be asynchronous, then you would see scalability benefits. This is because the thread could be released back to the .NET thread pool to handle another request, while ReturnAllCountries() is executing. This would allow your service to have higher throughput, by utilizing threads more efficiently.

Check if page gets reloaded or refreshed in JavaScript

First step is to check sessionStorage for some pre-defined value and if it exists alert user:

if (sessionStorage.getItem("is_reloaded")) alert('Reloaded!');

Second step is to set sessionStorage to some value (for example true):

sessionStorage.setItem("is_reloaded", true);

Session values kept until page is closed so it will work only if page reloaded in a new tab with the site. You can also keep reload count the same way.

How to drop columns by name in a data frame

I can´t answer your question in the comments due to low reputation score.

The next code will give you an error because the paste function return a character string

for(i in 1:length(var.out)) {
   paste("data$", var.out[i], sep="") <- NULL
}

Here is a possible solution:

for(i in 1:length(var.out)) {

  text_to_source <- paste0 ("data$", var.out[i], "<- NULL") # Write a line of your
                                                  # code like a character string
  eval (parse (text=text_to_source)) # Source a text that contains a code
}

or just do:

for(i in 1:length(var.out)) {
  data[var.out[i]] <- NULL
}

HQL ERROR: Path expected for join

select u from UserGroup ug inner join ug.user u 
where ug.group_id = :groupId 
order by u.lastname

As a named query:

@NamedQuery(
  name = "User.findByGroupId",
  query =
    "SELECT u FROM UserGroup ug " +
    "INNER JOIN ug.user u WHERE ug.group_id = :groupId ORDER BY u.lastname"
)

Use paths in the HQL statement, from one entity to the other. See the Hibernate documentation on HQL and joins for details.

What does @@variable mean in Ruby?

@ - Instance variable of a class
@@ - Class variable, also called as static variable in some cases

A class variable is a variable that is shared amongst all instances of a class. This means that only one variable value exists for all objects instantiated from this class. If one object instance changes the value of the variable, that new value will essentially change for all other object instances.

Another way of thinking of thinking of class variables is as global variables within the context of a single class. Class variables are declared by prefixing the variable name with two @ characters (@@). Class variables must be initialized at creation time

How to clone a Date object?

_x000D_

var orig = new Date();
var copy = new Date(+orig);

console.log(orig, copy);

_x000D_

How to read a file in reverse order?

a simple function to create a second file reversed (linux only):

import os
def tac(file1, file2):
     print(os.system('tac %s > %s' % (file1,file2)))

how to use

tac('ordered.csv', 'reversed.csv')
f = open('reversed.csv')

Animate background image change with jQuery

$('.clickable').hover(function(){
      $('.selector').stop(true,true).fadeTo( 400 , 0.0, function() {
        $('.selector').css('background-image',"url('assets/img/pic2.jpg')");
        });
    $('.selector').fadeTo( 400 , 1);
},
function(){
      $('.selector').stop(false,true).fadeTo( 400 , 0.0, function() {
        $('.selector').css('background-image',"url('assets/img/pic.jpg')");
        });
    $('.selector').fadeTo( 400 , 1);
}

);

What equivalents are there to TortoiseSVN, on Mac OSX?

Have a look at this archived question: TortoiseSVN for Mac? at superuser. (Original question was removed, so only archive remains.)

Have a look at this page for more likely up to date alternatives to TortoiseSVN for Mac: Alternative to: TortoiseSVN

How to create a sleep/delay in nodejs that is Blocking?

It's pretty trivial to implement with native addon, so someone did that: https://github.com/ErikDubbelboer/node-sleep.git

Is the NOLOCK (Sql Server hint) bad practice?

As a professional Developer I'd say it depends. But I definitely follow GATS and OMG Ponies advice. Know What You are doing, know when it helps and when it hurts and

read hints and other poor ideas

what might make You understand the sql server deeper. I generally follow the rule that SQL Hints are EVIL, but unfortunately I use them every now and then when I get fed up with forcing SQL server do things... But these are rare cases.

luke

Android Studio cannot resolve R in imported project?

None of these answers helped me!

My problem was not a problem! The program could compile completely and run on the device but the IDE has given me an annoying syntax error. It has underlined the lines of codes that included "R.".

The way that I could solve this issue:

I just added these three classes in "myapp/gen/com.example.app/" folder:

BuildConfig

package com.example.app;
public final class BuildConfig {
    public final static boolean DEBUG = true;
}

Manifest

package com.example.app;
public final class Manifest {
}

package com.example.app;
public final class R {
}

How to avoid Number Format Exception in java?

As always, the Jakarta Commons have at least part of the answer :

NumberUtils.isNumber()

This can be used to check most whether a given String is a number. You still have to choose what to do in case your String isnt a number ...

Verifying a specific parameter with Moq

If the verification logic is non-trivial, it will be messy to write a large lambda method (as your example shows). You could put all the test statements in a separate method, but I don't like to do this because it disrupts the flow of reading the test code.

Another option is to use a callback on the Setup call to store the value that was passed into the mocked method, and then write standard Assert methods to validate it. For example:

// Arrange
MyObject saveObject;
mock.Setup(c => c.Method(It.IsAny<int>(), It.IsAny<MyObject>()))
        .Callback<int, MyObject>((i, obj) => saveObject = obj)
        .Returns("xyzzy");

// Act
// ...

// Assert
// Verify Method was called once only
mock.Verify(c => c.Method(It.IsAny<int>(), It.IsAny<MyObject>()), Times.Once());
// Assert about saveObject
Assert.That(saveObject.TheProperty, Is.EqualTo(2));

good postgresql client for windows?

I heartily recommended dbVis. The client runs on Mac, Windows and Linux and supports a variety of database servers, including PostgreSQL.

MySQL Sum() multiple columns

You could change the database structure such that all subject rows become a column variable (like spreadsheet). This makes such analysis much easier

Select multiple elements from a list

mylist[c(5,7,9)] should do it.

You want the sublists returned as sublists of the result list; you don't use [[]] (or rather, the function is [[) for that -- as Dason mentions in comments, [[ grabs the element.

oracle SQL how to remove time from date

We can use TRUNC function in Oracle DB. Here is an example.

SELECT TRUNC(TO_DATE('01 Jan 2018 08:00:00','DD-MON-YYYY HH24:MI:SS')) FROM DUAL

Output: 1/1/2018

change image opacity using javascript

I'm not sure if you can do this in every browser but you can set the css property of the specified img.
Try to work with jQuery which allows you to make css changes much faster and efficiently.
in jQuery you will have the options of using .animate(),.fadeTo(),.fadeIn(),.hide("slow"),.show("slow") for example.
I mean this CSS snippet should do the work for you:

img
{
opacity:0.4;
filter:alpha(opacity=40); /* For IE8 and earlier */
}

Also check out this website where everything further is explained:
http://www.w3schools.com/css/css_image_transparency.asp

Getting MAC Address

The pure python solution for this problem under Linux to get the MAC for a specific local interface, originally posted as a comment by vishnubob and improved by on Ben Mackey in this activestate recipe

#!/usr/bin/python

import fcntl, socket, struct

def getHwAddr(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    info = fcntl.ioctl(s.fileno(), 0x8927,  struct.pack('256s', ifname[:15]))
    return ':'.join(['%02x' % ord(char) for char in info[18:24]])

print getHwAddr('eth0')

This is the Python 3 compatible code:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import fcntl
import socket
import struct


def getHwAddr(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    info = fcntl.ioctl(s.fileno(), 0x8927,  struct.pack('256s', bytes(ifname, 'utf-8')[:15]))
    return ':'.join('%02x' % b for b in info[18:24])


def main():
    print(getHwAddr('enp0s8'))


if __name__ == "__main__":
    main()

Form content type for a json HTTP POST?

It looks like people answered the first part of your question (use application/json).

For the second part: It is perfectly legal to send query parameters in a HTTP POST Request.

Example:

POST /members?id=1234 HTTP/1.1
Host: www.example.com
Content-Type: application/json

{"email":"[email protected]"}

Query parameters are commonly used in a POST request to refer to an existing resource. The above example would update the email address of an existing member with the id of 1234.

What is the difference between '@' and '=' in directive scope in AngularJS?

Why do I have to use "{{title}}" with '@' and "title" with '='?

When you use {{title}} , only the parent scope value will be passed to directive view and evaluated. This is limited to one way, meaning that change will not be reflected in parent scope. You can use '=' when you want to reflect the changes done in child directive to parent scope also. This is two way.

Can I also access the parent scope directly, without decorating my element with an attribute?

When directive has scope attribute in it ( scope : {} ), then you no longer will be able to access parent scope directly. But still it is possible to access it via scope.$parent etc. If you remove scope from directive, it can be accessed directly.

The documentation says "Often it's desirable to pass data from the isolated scope via an expression and to the parent scope", but that seems to work fine with bidirectional binding too. Why would the expression route be better?

It depends based on context. If you want to call an expression or function with data, you use & and if you want share data , you can use biderectional way using '='

You can find the differences between multiple ways of passing data to directive at below link:

AngularJS – Isolated Scopes – @ vs = vs &

http://www.codeforeach.com/angularjs/angularjs-isolated-scopes-vs-vs

Simulate user input in bash script

Here is a snippet I wrote; to ask for users' password and set it in /etc/passwd. You can manipulate it a little probably to get what you need:

echo -n " Please enter the password for the given user: "
read userPass
useradd $userAcct && echo -e "$userPass\n$userPass\n" | passwd $userAcct > /dev/null 2>&1 && echo " User account has been created." || echo " ERR -- User account creation failed!"

Remove an entire column from a data.frame in R

There are several options for removing one or more columns with dplyr::select() and some helper functions. The helper functions can be useful because some do not require naming all the specific columns to be dropped. Note that to drop columns using select() you need to use a leading - to negate the column names.

Using the dplyr::starwars sample data for some variety in column names:

library(dplyr)

starwars %>% 
  select(-height) %>%                  # a specific column name
  select(-one_of('mass', 'films')) %>% # any columns named in one_of()
  select(-(name:hair_color)) %>%       # the range of columns from 'name' to 'hair_color'
  select(-contains('color')) %>%       # any column name that contains 'color'
  select(-starts_with('bi')) %>%       # any column name that starts with 'bi'
  select(-ends_with('er')) %>%         # any column name that ends with 'er'
  select(-matches('^v.+s$')) %>%       # any column name matching the regex pattern
  select_if(~!is.list(.)) %>%          # not by column name but by data type
  head(2)

# A tibble: 2 x 2
homeworld species
  <chr>     <chr>  
1 Tatooine  Human  
2 Tatooine  Droid

You can also drop by column number:

starwars %>% 
  select(-2, -(4:10)) # column 2 and columns 4 through 10

Using SSH keys inside docker container

Docker containers should be seen as 'services' of their own. To separate concerns you should separate functionalities:

1) Data should be in a data container: use a linked volume to clone the repo into. That data container can then be linked to the service needing it.

2) Use a container to run the git cloning task, (i.e it's only job is cloning) linking the data container to it when you run it.

3) Same for the ssh-key: put it is a volume (as suggested above) and link it to the git clone service when you need it

That way, both the cloning task and the key are ephemeral and only active when needed.

Now if your app itself is a git interface, you might want to consider github or bitbucket REST APIs directly to do your work: that's what they were designed for.

rails + MySQL on OSX: Library not loaded: libmysqlclient.18.dylib

For MySql 5.6 installed from DMG on Mavericks

sudo ln -s /usr/local/mysql-5.6.14-osx10.7-x86_64/lib/libmysqlclient.18.dylib /usr/lib/libmysqlclient.18.dylib

Visual Studio - How to change a project's folder name and solution name without breaking the solution

I found that these instructions were not enough. I also had to search through the code files for models, controllers, and views as well as the AppStart files to change the namespace.

Since I was copying my project not just renaming it, I also had to go into the applicationhost.config for IIS express and recreate the bindings using different port numbers and change the physical directory as well.

Good tutorial for using HTML5 History API (Pushstate?)

Here is a great screen-cast on the topic by Ryan Bates of railscasts. At the end he simply disables the ajax functionality if the history.pushState method is not available:

http://railscasts.com/episodes/246-ajax-history-state

PHP Parse error: syntax error, unexpected '?' in helpers.php 233

If you came across this error while using the command line its because you must be using php 7 to execute whatever it is you are trying to execute. What happened is that the code is trying to use an operator thats only available in php7+ and is causing a syntax error.

If you already have php 7+ on your computer try pointing the command line to the higher version of php you want to use.

export PATH=/usr/local/[php-7-folder]/bin/:$PATH

Here is the exact location that worked based off of my setup for reference:

export PATH=/usr/local/php5-7.1.4-20170506-100436/bin/:$PATH

The operator thats actually caused the break is the "null coalesce operator" you can read more about it here:

php7 New Operators

Error when trying to access XAMPP from a network

In your xampppath\apache\conf\extra open file httpd-xampp.conf and find the below tag:

# Close XAMPP sites here
<LocationMatch "^/(?i:(?:xampp|licenses|phpmyadmin|webalizer|server-status|server-info))">
    Order deny,allow
    Deny from all
    Allow from ::1 127.0.0.0/8 
    ErrorDocument 403 /error/HTTP_XAMPP_FORBIDDEN.html.var
</LocationMatch>

and add

"Allow from all"

after Allow from ::1 127.0.0.0/8 {line}

Restart xampp, and you are done.

In later versions of Xampp

...you can simply remove this part

#
# New XAMPP security concept
#
<LocationMatch "^/(?i:(?:xampp|security|licenses|phpmyadmin|webalizer|server-status|server-info))">
        Require local
    ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var
</LocationMatch>

from the same file and it should work over the local network.

Open Bootstrap Modal from code-behind

Maybe this answer is so late, but it's useful.
to do it,we have 3 steps:
1- Create a modal structure in HTML.
2- Create a button to call a function in java script, to open modal and set display:none in CSS .
3- Call this button by function in code behind .
you can see these steps in below snippet :

HTML modal:

<div class="modal fade" id="myModal">
                <div class="modal-dialog">
                    <div class="modal-content">
                        <div class="modal-header">
                            <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                                <span aria-hidden="true">&times;</span></button>
                            <h4 class="modal-title">
                                Registration done Successfully</h4>
                        </div>
                        <div class="modal-body">
                            <asp:Label ID="lblMessage" runat="server" />
                        </div>
                        <div class="modal-footer">
                            <button type="button" class="btn btn-default" data-dismiss="modal">
                                Close</button>
                            <button type="button" class="btn btn-primary">
                                Save changes</button>
                        </div>
                    </div>
                    <!-- /.modal-content -->
                </div>
                <!-- /.modal-dialog -->
            </div>
            <!-- /.modal -->

Hidden Button:

<button type="button" style="display: none;" id="btnShowPopup" class="btn btn-primary btn-lg"
                data-toggle="modal" data-target="#myModal">
                Launch demo modal
            </button>

Script Code:

<script type="text/javascript">
        function ShowPopup() {
            $("#btnShowPopup").click();
        }
    </script>

code behind:

protected void Page_Load(object sender, EventArgs e)
{
    ClientScript.RegisterStartupScript(this.GetType(), "alert", "ShowPopup();", true);
    this.lblMessage.Text = "Your Registration is done successfully. Our team will contact you shotly";
}

this solution is one of any solutions that I used it .

How to check Django version

There is an undocumented utils versions module in Django:

https://github.com/django/django/blob/master/django/utils/version.py

With that, you can get the normal version as a string or a detailed version tuple:

>>> from django.utils import version
>>> version.get_version()
... 1.9
>>> version.get_complete_version()
... (1, 9, 0, 'final', 0)

How to parse JSON using Node.js?

you can require .json files.

var parsedJSON = require('./file-name');

For example if you have a config.json file in the same directory as your source code file you would use:

var config = require('./config.json');

or (file extension can be omitted):

var config = require('./config');

note that require is synchronous and only reads the file once, following calls return the result from cache

Also note You should only use this for local files under your absolute control, as it potentially executes any code within the file.

Know relationships between all the tables of database in SQL Server

Just another way to retrieve the same data using INFORMATION_SCHEMA

The information schema views included in SQL Server comply with the ISO standard definition for the INFORMATION_SCHEMA.

sqlauthority way

SELECT
K_Table = FK.TABLE_NAME,
FK_Column = CU.COLUMN_NAME,
PK_Table = PK.TABLE_NAME,
PK_Column = PT.COLUMN_NAME,
Constraint_Name = C.CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
INNER JOIN (
SELECT i1.TABLE_NAME, i2.COLUMN_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2 ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
) PT ON PT.TABLE_NAME = PK.TABLE_NAME
---- optional:
ORDER BY
1,2,3,4
WHERE PK.TABLE_NAME='something'WHERE FK.TABLE_NAME='something'
WHERE PK.TABLE_NAME IN ('one_thing', 'another')
WHERE FK.TABLE_NAME IN ('one_thing', 'another')

Force re-download of release dependency using Maven

If you know the group id of X, you can use this command to redownload all of X and it's dependencies

mvn clean dependency:purge-local-repository -DresolutionFuzziness=org.id.of.x

It does the same thing as the other answers that propose using dependency:purge-local-repository, but it only deletes and redownloads everything related to X.

How can I check if a user is logged-in in php?

You may do a session and place it:

// Start session
session_start();

// Check do the person logged in
if($_SESSION['username']==NULL){
    // Haven't log in
    echo "You haven't log in";
}else{
    // Logged in
    echo "Successfully logged in!";
}

Note: you must make a form which contain $_SESSION['username'] = $login_input_username;

How to install pywin32 module in windows 7

I disagree with the accepted answer being "the easiest", particularly if you want to use virtualenv.

You can use the Unofficial Windows Binaries instead. Download the appropriate wheel from there, and install it with pip:

pip install pywin32-219-cp27-none-win32.whl

(Make sure you pick the one for the right version and bitness of Python).

You might be able to get the URL and install it via pip without downloading it first, but they're made it a bit harder to just grab the URL. Probably better to download it and host it somewhere yourself.

Finding rows that don't contain numeric data in Oracle

I've found this useful:

 select translate('your string','_0123456789','_') from dual

If the result is NULL, it's numeric (ignoring floating point numbers.)

However, I'm a bit baffled why the underscore is needed. Without it the following also returns null:

 select translate('s123','0123456789', '') from dual

There is also one of my favorite tricks - not perfect if the string contains stuff like "*" or "#":

 SELECT 'is a number' FROM dual WHERE UPPER('123') = LOWER('123')

How to Decrease Image Brightness in CSS

You can use css filters, below and example for web-kit. please look at this example: http://jsfiddle.net/m9sjdbx6/4/

    img { -webkit-filter: brightness(0.2);}

How to align texts inside of an input?

Use the text-align property in your CSS:

input { 
    text-align: right; 
}

This will take effect in all the inputs of the page.
Otherwise, if you want to align the text of just one input, set the style inline:

<input type="text" style="text-align:right;"/>

How to draw a custom UIView that is just a circle - iPhone app

Swift 3 - custom class, easy to reuse. It uses backgroundColor set in UI builder

import UIKit

@IBDesignable
class CircleBackgroundView: UIView {

    override func layoutSubviews() {
        super.layoutSubviews()
        layer.cornerRadius = bounds.size.width / 2
        layer.masksToBounds = true
    }

}

Sorting multiple keys with Unix sort

I just want to add some tips, when you using sort , be careful about your locale that effects the order of the key comparison. I usually explicitly use LC_ALL=C to make locale what I want.

Get number of digits with JavaScript

you can use the Math.abs function to turn negative numbers to positive and keep positives as it is. then you can convert the number to string and provide length. look at this function:

const digitCount = num => Math.abs(num).toString().length;

i found this method the easiest and it works pretty good.

hash keys / values as array

Don't know if it helps, but the "foreach" goes through all the keys: for (var key in obj1) {...}

Can I call methods in constructor in Java?

Better design would be

public static YourObject getMyObject(File configFile){
    //process and create an object configure it and return it
}

Factory design pattern

How do I create a right click context menu in Java Swing?

There's a section on Bringing Up a Popup Menu in the How to Use Menus article of The Java Tutorials which explains how to use the JPopupMenu class.

The example code in the tutorial shows how to add MouseListeners to the components which should display a pop-up menu, and displays the menu accordingly.

(The method you describe is fairly similar to the way the tutorial presents the way to show a pop-up menu on a component.)

Select subset of columns in data.table R

This seems an improvement:

> cols<-!(colnames(dt) %in% c("V1","V2","V3","V5"))
> new_dt<-subset(dt,,cols)
> cor(new_dt)
            V4          V6          V7          V8         V9         V10
V4   1.0000000  0.14141578 -0.44466832  0.23697216 -0.1020074  0.48171747
V6   0.1414158  1.00000000 -0.21356218 -0.08510977 -0.1884202 -0.22242274
V7  -0.4446683 -0.21356218  1.00000000 -0.02050846  0.3209454 -0.15021528
V8   0.2369722 -0.08510977 -0.02050846  1.00000000  0.4627034 -0.07020571
V9  -0.1020074 -0.18842023  0.32094540  0.46270335  1.0000000 -0.19224973
V10  0.4817175 -0.22242274 -0.15021528 -0.07020571 -0.1922497  1.00000000

This one is not quite as easy to grasp but might have use for situations there there were a need to specify columns by a numeric vector:

subset(dt, , !grepl(paste0("V", c(1:3,5),collapse="|"),colnames(dt) ))

How do I access ViewBag from JS

You can achieve the solution, by doing this:

JavaScript:

var myValue = document.getElementById("@(ViewBag.CC)").value;

or if you want to use jQuery, then:

jQuery

var myValue = $('#' + '@(ViewBag.CC)').val();

What is the purpose of meshgrid in Python / NumPy?

Suppose you have a function:

def sinus2d(x, y):
    return np.sin(x) + np.sin(y)

and you want, for example, to see what it looks like in the range 0 to 2*pi. How would you do it? There np.meshgrid comes in:

xx, yy = np.meshgrid(np.linspace(0,2*np.pi,100), np.linspace(0,2*np.pi,100))
z = sinus2d(xx, yy) # Create the image on this grid

and such a plot would look like:

import matplotlib.pyplot as plt
plt.imshow(z, origin='lower', interpolation='none')
plt.show()

So np.meshgrid is just a convenience. In principle the same could be done by:

z2 = sinus2d(np.linspace(0,2*np.pi,100)[:,None], np.linspace(0,2*np.pi,100)[None,:])

but there you need to be aware of your dimensions (suppose you have more than two ...) and the right broadcasting. np.meshgrid does all of this for you.

Also meshgrid allows you to delete coordinates together with the data if you, for example, want to do an interpolation but exclude certain values:

condition = z>0.6
z_new = z[condition] # This will make your array 1D

so how would you do the interpolation now? You can give x and y to an interpolation function like scipy.interpolate.interp2d so you need a way to know which coordinates were deleted:

x_new = xx[condition]
y_new = yy[condition]

and then you can still interpolate with the "right" coordinates (try it without the meshgrid and you will have a lot of extra code):

from scipy.interpolate import interp2d
interpolated = interp2d(x_new, y_new, z_new)

and the original meshgrid allows you to get the interpolation on the original grid again:

interpolated_grid = interpolated(xx[0], yy[:, 0]).reshape(xx.shape)

These are just some examples where I used the meshgrid there might be a lot more.

Copy and paste content from one file to another file in vi

Here's one way to do it;

Start Vim and open file1 which is the file you're working on.
:e file2 which will bring up file2, the file you want to copy lines from.
locate the lines you want to copy. If it's three lines, you hit 3yy
:b1 this will switch to buffer 1, where file1 is
figure out where you want to insert the lines you yanked, and hit p

You could have both files viewable too. Split the screen with e.g. Ctrl + w s.

As for cutting, d cuts and places the cut stuff in the yank buffer. dd will "cut" a line.

batch/bat to copy folder and content at once

I suspect that the xcopy command is the magic bullet you're looking for.

It can copy files, directories, and even entire drives while preserving the original directory hierarchy. There are also a handful of additional options available, compared to the basic copy command.

Check out the documentation here.

If your batch file only needs to run on Windows Vista or later, you can use robocopy instead, which is an even more powerful tool than xcopy, and is now built into the operating system. It's documentation is available here.

PHP code to remove everything but numbers

You would need to enclose the pattern in a delimiter - typically a slash (/) is used. Try this:

echo preg_replace("/[^0-9]/","",'604-619-5135');

Number format in excel: Showing % value without multiplying with 100

_ [$%-4009] * #,##0_ ;_ [$%-4009] * -#,##0_ ;_ [$%-4009] * "-"??_ ;_ @_

JQuery refresh select box

Getting the IP Address of a Remote Socket Endpoint

http://msdn.microsoft.com/en-us/library/system.net.sockets.socket.remoteendpoint.aspx

You can then call the IPEndPoint..::.Address method to retrieve the remote IPAddress, and the IPEndPoint..::.Port method to retrieve the remote port number.

JavaScript Nested function

It is called closure.

Basically, the function defined within other function is accessible only within this function. But may be passed as a result and then this result may be called.

It is a very powerful feature. You can see more explanation here:

javascript_closures_for_dummies.html mirror on Archive.org

How to get absolute value from double - c-language

Use fabs() (in math.h) to get absolute-value for double:

double d1 = fabs(-3.8951);

Convert string to number field

Within Crystal, you can do it by creating a formula that uses the ToNumber function. It might be a good idea to code for the possibility that the field might include non-numeric data - like so:

If NumericText ({field}) then ToNumber ({field}) else 0

Alternatively, you might find it easier to convert the field's datatype within the query used in the report.

AngularJS sorting rows by table header

Here is a fiddle that can help you to do this with AngularJS
http://jsfiddle.net/patxy/D2FsZ/

<th ng:repeat="(i,th) in head" ng:class="selectedCls(i)" ng:click="changeSorting(i)">
     {{th}}
</th>

Then something like this for your data:

<tr ng:repeat="row in body.$orderBy(sort.column, sort.descending)">
    <td>{{row.a}}</td>
    <td>{{row.b}}</td>
    <td>{{row.c}}</td>
</tr>

With such functions in your AngularJS controller:

scope.sort = {
    column: 'b',
    descending: false
};

scope.selectedCls = function(column) {
    return column == scope.sort.column && 'sort-' + scope.sort.descending;
};

scope.changeSorting = function(column) {
    var sort = scope.sort;
    if (sort.column == column) {
        sort.descending = !sort.descending;
    } else {
        sort.column = column;
        sort.descending = false;
    }
};

How to fire a change event on a HTMLSelectElement if the new value is the same as the old?

I'd do it like this:

<select onchange="jsFunction()">
  <option value="" disabled selected style="display:none;">Label</option>
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
</select>

If you want you could have the same label as the first option, which in this case is 1. Even better: put a label in there for the choices in the box.

Programs & Examples On #Application name

Bootstrap 4 responsive tables won't take up 100% width

/etc/apt/sources.list" E212: Can't open file for writing

onclick="javascript:history.go(-1)" not working in Chrome

SQL RANK() over PARTITION on joined tables

How do I resolve the "java.net.BindException: Address already in use: JVM_Bind" error?

Twitter Bootstrap 3 Sticky Footer

Can not connect to local PostgreSQL

When I run `npm install`, it returns with `ERR! code EINTEGRITY` (npm 5.3.0)

Where is PHP.ini in Mac OS X Lion? Thought it was in /usr/local/php5/lib

How to compare dates in c#

Convert object string to JSON

Html.Partial vs Html.RenderPartial & Html.Action vs Html.RenderAction

How can I pass a class member function as a callback?

Understanding timedelta

How to delete the contents of a folder?

What is the JSF resource library for and how should it be used?

Real world examples

Easier identifying

Your own webapp

Library versioning

See also:

How to capture a JFrame's close button click event?

Postgres integer arrays as parameters?

How do I check if an HTML element is empty using jQuery?

Could not load type from assembly error

Redirect to an external URL from controller action in Spring MVC

How do I include inline JavaScript in Haml?

How to focus on a form input text field on page load using jQuery?

find index of an int in a list

How to process a file in PowerShell line-by-line as a stream

"fatal: Not a git repository (or any of the parent directories)" from git status

How to hide the border for specified rows of a table?

how to install python distutils

How to iterate through table in Lua?

How to add rows dynamically into table layout

Correct way of looping through C++ arrays

Refused to execute script, strict MIME type checking is enabled?

Set markers for individual points on a line in Matplotlib

Retrieve a single file from a repository

Angularjs error Unknown provider

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

did you register the component correctly? For recursive components, make sure to provide the "name" option

Decode HTML entities in Python string?

PostgreSQL unnest() with element number

Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

How to get the number of threads in a Java process

Possible to perform cross-database queries with PostgreSQL?

How do I insert an image in an activity with android studio?

Declare Variable for a Query String

Using EXEC

Using sp_executesql

How do I scroll the UIScrollView when the keyboard appears?

java.lang.ClassNotFoundException: Didn't find class on path: dexpathlist

HTML Form Redirect After Submit

Connect to docker container as user other than root

"Undefined reference to" template class constructor

Understanding the problem

Answer 1: Explicitly instantiate the template, and its member definitions

Answer 2: Copy the code into the relevant header file

Summary

Multiple SQL joins

JavaScript global event mechanism

what is the difference between GROUP BY and ORDER BY in sql

How do I display a wordpress page content?

error : expected unqualified-id before return in c++

Convert datetime object to a String of date only in Python

Get top 1 row of each group

Distinct by property of class with LINQ

Efficient SQL test query or validation query that will work across all (or most) databases

Using python's mock patch.object to change the return value of a method called within another method

Setting selected values for ng-options bound select elements

Best way to convert an ArrayList to a string

Android change SDK version in Eclipse? Unable to resolve target android-x

"SyntaxError: Unexpected token < in JSON at position 0"

Regular expression to find two strings anywhere in input

How to write palindrome in JavaScript

What's the default password of mariadb on fedora?

Text size and different android screen sizes

Change SQLite database mode to read-write

#1. Using `NSPredicate` `init(format:arguments:)` initializer

#2. Using `NSPredicate` `init(block:)` initializer