Programs & Examples On #Slimbox

Slimbox is a lightweight "light-box overlay" script similar to Lightbox.

how to use a like with a join in sql?

When writing queries with our server LIKE or INSTR (or CHARINDEX in T-SQL) takes too long, so we use LEFT like in the following structure:

select *
from little
left join big
on left( big.key, len(little.key) ) = little.key

I understand that might only work with varying endings to the query, unlike other suggestions with '%' + b + '%', but is enough and much faster if you only need b+'%'.

Another way to optimize it for speed (but not memory) is to create a column in "little" that is "len(little.key)" as "lenkey" and user that instead in the query above.

How to prevent form resubmission when page is refreshed (F5 / CTRL+R)

This method works for me well, and I think this is the simplest one to do this job.

The general idea is to redirect the user to some other pages after the form submission, which would stop the form resubmission on page refresh. Still, if you need to hold the user on the same page after the form is submitted, you can do it in multiple ways, but here I am describing the javascript method.

Javascript Method

This method is quite easy and blocks the pop up asking for form resubmission on refresh once the form is submitted. Just place this line of javascript code at the footer of your file and see the magic.

_x000D_
_x000D_
<script>_x000D_
if ( window.history.replaceState ) {_x000D_
  window.history.replaceState( null, null, window.location.href );_x000D_
}_x000D_
</script>
_x000D_
_x000D_
_x000D_

How can I remove the extension of a filename in a shell script?

You should be using the command substitution syntax $(command) when you want to execute a command in script/command.

So your line would be

name=$(echo "$filename" | cut -f 1 -d '.')

Code explanation:

  1. echo get the value of the variable $filename and send it to standard output
  2. We then grab the output and pipe it to the cut command
  3. The cut will use the . as delimiter (also known as separator) for cutting the string into segments and by -f we select which segment we want to have in output
  4. Then the $() command substitution will get the output and return its value
  5. The returned value will be assigned to the variable named name

Note that this gives the portion of the variable up to the first period .:

$ filename=hello.world
$ echo "$filename" | cut -f 1 -d '.'
hello
$ filename=hello.hello.hello
$ echo "$filename" | cut -f 1 -d '.'
hello
$ filename=hello
$ echo "$filename" | cut -f 1 -d '.'
hello

How to Display blob (.pdf) in an AngularJS app

Most recent answer (for Angular 8+):

this.http.post("your-url",params,{responseType:'arraybuffer' as 'json'}).subscribe(
  (res) => {
    this.showpdf(res);
  }
)};

public Content:SafeResourceUrl;
showpdf(response:ArrayBuffer) {
  var file = new Blob([response], {type: 'application/pdf'});
  var fileURL = URL.createObjectURL(file);
  this.Content = this.sanitizer.bypassSecurityTrustResourceUrl(fileURL);
}

  HTML :

  <embed [src]="Content" style="width:200px;height:200px;" type="application/pdf" />

Make Vim show ALL white spaces as a character

As others have said, you could use

:set list

which will, in combination with

:set listchars=...

display invisible characters.
Now, there isn't an explicit option which you can use to show whitespace, but in listchars, you could set a character to show for everything BUT whitespace. For example, mine looks like this

:set listchars=eol:$,tab:>-,trail:~,extends:>,precedes:<

so, now, after you use

:set list

everything that isn't explicitly shown as something else, is then, really, a plain old whitespace.

As usual, to understand how listchars works, use the help. It provides great information about what chars can be displayed (like trailing space, for instance) and how to do it:

:help listchars

It might be helpful to add a toggle to it so you can see the changes mid editing easily (source: VIM :set list! as a toggle in .vimrc):

noremap <F5> :set list!<CR>
inoremap <F5> <C-o>:set list!<CR>
cnoremap <F5> <C-c>:set list!<CR>

Passing $_POST values with cURL

<?php
    function executeCurl($arrOptions) {

        $mixCH = curl_init();

        foreach ($arrOptions as $strCurlOpt => $mixCurlOptValue) {
            curl_setopt($mixCH, $strCurlOpt, $mixCurlOptValue);
        }

        $mixResponse = curl_exec($mixCH);
        curl_close($mixCH);
        return $mixResponse;
    }

    // If any HTTP authentication is needed.
    $username = 'http-auth-username';
    $password = 'http-auth-password';

    $requestType = 'POST'; // This can be PUT or POST

    // This is a sample array. You can use $arrPostData = $_POST
    $arrPostData = array(
        'key1'  => 'value-1-for-k1y-1',
        'key2'  => 'value-2-for-key-2',
        'key3'  => array(
                'key31'   => 'value-for-key-3-1',
                'key32'   => array(
                    'key321' => 'value-for-key321'
                )
        ),
        'key4'  => array(
            'key'   => 'value'
        )
    );

    // You can set your post data
    $postData = http_build_query($arrPostData); // Raw PHP array

    $postData = json_encode($arrPostData); // Only USE this when request JSON data.

    $mixResponse = executeCurl(array(
        CURLOPT_URL => 'http://whatever-your-request-url.com/xyz/yii',
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HTTPGET => true,
        CURLOPT_VERBOSE => true,
        CURLOPT_AUTOREFERER => true,
        CURLOPT_CUSTOMREQUEST => $requestType,
        CURLOPT_POSTFIELDS  => $postData,
        CURLOPT_HTTPHEADER  => array(
            "X-HTTP-Method-Override: " . $requestType,
            'Content-Type: application/json', // Only USE this when requesting JSON data
        ),

        // If HTTP authentication is required, use the below lines.
        CURLOPT_HTTPAUTH => CURLAUTH_BASIC,
        CURLOPT_USERPWD  => $username. ':' . $password
    ));

    // $mixResponse contains your server response.

python convert list to dictionary

Not sure whether it would help you or not but it works to me:

l = ["a", "b", "c", "d", "e"]
outRes = dict((l[i], l[i+1]) if i+1 < len(l) else (l[i], '') for i in xrange(len(l)))

Dropping a connected user from an Oracle 10g database schema

just use SQL :

disconnect; 

conn tiger/scott as sysdba;

How do I set a JLabel's background color?

For the Background, make sure you have imported java.awt.Color into your package.

In your main method, i.e. public static void main(String[] args), call the already imported method:

JLabel name_of_your_label=new JLabel("the title of your label");
name_of_your_label.setBackground(Color.the_color_you_wish);
name_of_your_label.setOpaque(true);

NB: Setting opaque will affect its visibility. Remember the case sensitivity in Java.

How do I create a dictionary with keys from a list and values defaulting to (say) zero?

d = dict([(x,0) for x in a])

**edit Tim's solution is better because it uses generators see the comment to his answer.

Split a String into an array in Swift?

Most of these answers assume the input contains a space - not whitespace, and a single space at that. If you can safely make that assumption, then the accepted answer (from bennett) is quite elegant and also the method I'll be going with when I can.

When we can't make that assumption, a more robust solution needs to cover the following siutations that most answers here don't consider:

  • tabs/newlines/spaces (whitespace), including recurring characters
  • leading/trailing whitespace
  • Apple/Linux (\n) and Windows (\r\n) newline characters

To cover these cases this solution uses regex to convert all whitespace (including recurring and Windows newline characters) to a single space, trims, then splits by a single space:

Swift 3:

let searchInput = "  First \r\n \n \t\t\tMiddle    Last "
let searchTerms = searchInput 
    .replacingOccurrences(
        of: "\\s+",
        with: " ",
        options: .regularExpression
    )
    .trimmingCharacters(in: .whitespaces)
    .components(separatedBy: " ")

// searchTerms == ["First", "Middle", "Last"]

How do I fix the npm UNMET PEER DEPENDENCY warning?

The given answer wont always work. If it does not fix your issue. Make sure that you are also using the correct symbol in your package.json. This is very important to fix that headache. For example:

warning " > @angular/[email protected]" has incorrect peer dependency "typescript@>=2.4.2 <2.7".
warning " > [email protected]" has incorrect peer dependency "typescript@>=2.4.2 <2.6".

So my typescript needs to be between 2.4.2 and 2.6 right?

So I changed my typescript library from using "typescript": "^2.7" to using "typescript": "^2.5". Seems correct?

Wrong.

The ^ means that you are okay with npm using "typescript": "2.5" or "2.6" or "2.7" etc...

If you want to learn what the ^ and ~ it mean see: What's the difference between tilde(~) and caret(^) in package.json?

Also you have to make sure that the package exists. Maybe there is no "typescript": "2.5.9" look up the package numbers. To be really safe just remove the ~ or the ^ if you dont want to read what they mean.

How to fix the Eclipse executable launcher was unable to locate its companion shared library for windows 7?

The reason to that might be the 2 lines in eclipse.ini

--launcher.library
C:\Users\UserName\.p2\pool\plugins\org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.400.v20160518-1444

for my case the reason was admin privilages so I had to move the folder from the path specified in ini to my eclipse plugins and change path in ini to :

plugins\org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.400.v20160518-1444

Set and Get Methods in java?

Above answers all assume that the object in question is an object with behaviour. An advanced strategy in OOP is to separate data objects (that do zip, only have fields) and behaviour objects.

With data objects, it is perfectly fine to omit getters and instead have public fields. They usually don't have setters, since they most commonly are immutable - their fields are set via the constructors, and never again. Have a look at Bob Martin's Clean Code or Pryce and Freeman's Growing OO Software... for details.

Deprecation warning in Moment.js - Not in a recognized ISO format

I have similar issue faced and solve with following solution: my date format is: 'Fri Dec 11 2020 05:00:00 GMT+0500 (Pakistan Standard Time)'

let currentDate = moment(new Date('Fri Dec 11 2020 05:00:00 GMT+0500 (Pakistan Standard Time)').format('DD-MM-YYYY'); // 'Fri Dec 11 2020 05:00:00 GMT+0500 (Pakistan Standard Time)'

let output=(moment(currentDate).isSameOrAfter('07-12-2020'));

What is the better API to Reading Excel sheets in java - JXL or Apache POI

I have used POI.

If you use that, keep on eye those cell formatters: create one and use it several times instead of creating each time for cell, it isa huge memory consumption difference or large data.

Giving my function access to outside variable

Global $myArr;
$myArr = array();

function someFuntion(){
    global $myArr;

    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
}

Be forewarned, generally people stick away from globals as it has some downsides.

You could try this

function someFuntion($myArr){
    $myVal = //some processing here to determine value of $myVal
    $myArr[] = $myVal;
    return $myArr;
}
$myArr = someFunction($myArr);

That would make it so you aren't relying on Globals.

Bootstrap close responsive menu "on click"

I'm assuming you have a line like this defining the nav area, based on Bootstrap examples and all

<div class="nav-collapse collapse" >

Simply add the properties as such, like on the MENU button

<div class="nav-collapse collapse" data-toggle="collapse"  data-target=".nav-collapse">

I've added to <body> as well, worked. Can't say I've profiled it or anything, but seems a treat to me...until you click on a random spot of the UI to open the menu, so not so good that.

DK

Why don’t my SVG images scale using the CSS "width" property?

SVGs are different than bitmap images such as PNG etc. If an SVG has a viewBox - as yours appear to - then it will be scaled to fit it's defined viewport. It won't directly scale like a PNG would.

So increasing the width of the img won't make the icons any taller if the height is restricted. You'll just end up with the img horizontally centred in a wider box.

I believe your problem is that your SVGs have a fixed height defined in them. Open up the SVG files and make sure they either:

  1. have no width and height defined, or
  2. have width and height both set to "100%".

That should solve your problem. If it doesn't, post one of your SVGs into your question so we can see how it is defined.

How do I replace text in a selection?

On a Mac you can can select the text that you are after then press: cmd + ctrl + G

This will select every instance of your selected text within the same document. If you now start typing to replace your original highlighted text, you will replace all of the other occurrences at the same time.

C function that counts lines in file

You have a ; at the end of the if. Change:

  if (fp == NULL);
  return 0;

to

  if (fp == NULL) 
    return 0;

rails simple_form - hidden field - create?

Shortest Yet !!!

=f.hidden_field :title, :value => "some value"

Shorter, DRYer and perhaps more obvious.

Of course with ruby 1.9 and the new hash format we can go 3 characters shorter with...

=f.hidden_field :title, value: "some value"

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

If someone is here who is using MySQL and felt that the code was working the previous day and now it doesn't, then I guess you must open MySQL CLI or MySQL Workbench and just make the connection to the database once. Once it gets connected, then the database also gets connected to the Java Application. I used to get the Hibernate Dialect error stating something wrong with com.mysql.jdbc.Driver. I think MySQL in some computers has a startup problem. This solved for me.

How to use Python requests to fake a browser visit a.k.a and generate User Agent?

Answer

You need to create a header with a proper formatted User agent String, it server to communicate client-server.

You can check your own user agent Here.

Example

Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0
Mozilla/5.0 (Macintosh; Intel Mac OS X x.y; rv:42.0) Gecko/20100101 Firefox/42.0

Third party Package user_agent 0.1.9

I found this module very simple to use, in one line of code it randomly generates a User agent string.

from user_agent import generate_user_agent, generate_navigator
from pprint import pprint

print(generate_user_agent())
# 'Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.3; Win64; x64)'

print(generate_user_agent(os=('mac', 'linux')))
# 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:36.0) Gecko/20100101 Firefox/36.0'

pprint(generate_navigator())

# {'app_code_name': 'Mozilla',
#  'app_name': 'Netscape',
#  'appversion': '5.0',
#  'name': 'firefox',
#  'os': 'linux',
#  'oscpu': 'Linux i686 on x86_64',
#  'platform': 'Linux i686 on x86_64',
#  'user_agent': 'Mozilla/5.0 (X11; Ubuntu; Linux i686 on x86_64; rv:41.0) Gecko/20100101 Firefox/41.0',
#  'version': '41.0'}

pprint(generate_navigator_js())

# {'appCodeName': 'Mozilla',
#  'appName': 'Netscape',
#  'appVersion': '38.0',
#  'platform': 'MacIntel',
#  'userAgent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:38.0) Gecko/20100101 Firefox/38.0'}

What is the difference between String.slice and String.substring?

The difference between substring and slice - is how they work with negative and overlooking lines abroad arguments:

substring (start, end)

Negative arguments are interpreted as zero. Too large values ??are truncated to the length of the string:   alert ( "testme" .substring (-2)); // "testme", -2 becomes 0

Furthermore, if start > end, the arguments are interchanged, i.e. plot line returns between the start and end:

alert ( "testme" .substring (4, -1)); // "test"
// -1 Becomes 0 -> got substring (4, 0)
// 4> 0, so that the arguments are swapped -> substring (0, 4) = "test"

slice

Negative values ??are measured from the end of the line:

alert ( "testme" .slice (-2)); // "me", from the end position 2
alert ( "testme" .slice (1, -1)); // "estm", from the first position to the one at the end.

It is much more convenient than the strange logic substring.

A negative value of the first parameter to substr supported in all browsers except IE8-.

If the choice of one of these three methods, for use in most situations - it will be slice: negative arguments and it maintains and operates most obvious.

JQuery get all elements by class name

With the code in the question, you're only dealing interacting with the first of the four entries returned by that selector.

Code below as a fiddle: https://jsfiddle.net/c4nhpqgb/

I want to be overly clear that you have four items that matched that selector, so you need to deal with each explicitly. Using eq() is a little more explicit making this point than the answers using map, though map or each is what you'd probably use "in real life" (jquery docs for eq here).

<html>
    <head>
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" ></script>
    </head>

    <body>
        <div class="mbox">Block One</div>
        <div class="mbox">Block Two</div>
        <div class="mbox">Block Three</div>
        <div class="mbox">Block Four</div>

        <div id="outige"></div>
        <script>
            // using the $ prefix to use the "jQuery wrapped var" convention
            var i, $mvar = $('.mbox');

            // convenience method to display unprocessed html on the same page
            function logit( string )
            {
                var text = document.createTextNode( string );
                $('#outige').append(text);
                $('#outige').append("<br>");
            }

            logit($mvar.length);

            for (i=0; i<$mvar.length; i++)    {
                logit($mvar.eq(i).html());
            }
        </script>
    </body>

</html>

Output from logit calls (after the initial four div's display):

4
Block One
Block Two
Block Three
Block Four

Grouping switch statement cases together?

Your example is as concise as it gets with the switch construct.

Is Python faster and lighter than C++?

The problem here is that you have two different languages that solve two different problems... its like comparing C++ with assembler.

Python is for rapid application development and for when performance is a minimal concern.

C++ is not for rapid application development and inherits a legacy of speed from C - for low level programming.

Shorter syntax for casting from a List<X> to a List<Y>?

This is not quite the answer to this question, but it may be useful for some: as @SWeko said, thanks to covariance and contravariance, List<X> can not be cast in List<Y>, but List<X> can be cast into IEnumerable<Y>, and even with implicit cast.

Example:

List<Y> ListOfY = new List<Y>();
List<X> ListOfX = (List<X>)ListOfY; // Compile error

but

List<Y> ListOfY = new List<Y>();
IEnumerable<X> EnumerableOfX = ListOfY;  // No issue

The big advantage is that it does not create a new list in memory.

How to build an APK file in Eclipse?

Right click on the project in Eclipse -> Android tools -> Export without signed key. Connect your device. Mount it by sdk/tools.

What is jQuery Unobtrusive Validation?

jQuery Validation Unobtrusive Native is a collection of ASP.Net MVC HTML helper extensions. These make use of jQuery Validation's native support for validation driven by HTML 5 data attributes. Microsoft shipped jquery.validate.unobtrusive.js back with MVC 3. It provided a way to apply data model validations to the client side using a combination of jQuery Validation and HTML 5 data attributes (that's the "unobtrusive" part).

Setting the height of a DIV dynamically

Try this simple, specific function:

function resizeElementHeight(element) {
  var height = 0;
  var body = window.document.body;
  if (window.innerHeight) {
      height = window.innerHeight;
  } else if (body.parentElement.clientHeight) {
      height = body.parentElement.clientHeight;
  } else if (body && body.clientHeight) {
      height = body.clientHeight;
  }
  element.style.height = ((height - element.offsetTop) + "px");
}

It does not depend on the current distance from the top of the body being specified (in case your 300px changes).


EDIT: By the way, you would want to call this on that div every time the user changed the browser's size, so you would need to wire up the event handler for that, of course.

Configuring RollingFileAppender in log4j

I'm suspicious of the ActiveFileName property. According to the log4j javadoc, there isn't such a property on the TimeBasedRollingPolicy class. (No setActiveFileName or getActiveFileName methods.)

I don't know what specifying an unknown property would do, but it is possible that it will cause the containing object to be abandoned, and that could lead to the warnings that you saw.

Try leaving it out and seeing what happens.

What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?

ArrayIndexOutOfBoundsException whenever this exception is coming it mean you are trying to use an index of array which is out of its bounds or in lay man terms you are requesting more than than you have initialised.

To prevent this always make sure that you are not requesting a index which is not present in array i.e. if array length is 10 then your index must range between 0 to 9

Android custom Row Item for ListView

create resource layout file list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:orientation="vertical"
          android:layout_width="match_parent"
          android:layout_height="wrap_content">
<TextView
        android:id="@+id/header_text"
        android:layout_height="0dp"
        android:layout_width="fill_parent"
        android:layout_weight="1"
        android:text="Header"
        />
<TextView
        android:id="@+id/item_text"
        android:layout_height="0dp"
        android:layout_width="fill_parent"
        android:layout_weight="1"
        android:text="dynamic text"
        />
</LinearLayout>

and initialise adaptor like this

adapter = new ArrayAdapter<String>(this, R.layout.list_item,R.id.item_text,data_array);

CSS3 :unchecked pseudo-class

There is no :unchecked pseudo class however if you use the :checked pseudo class and the sibling selector you can differentiate between both states. I believe all of the latest browsers support the :checked pseudo class, you can find more info from this resource: http://www.whatstyle.net/articles/18/pretty_form_controls_with_css

Your going to get better browser support with jquery... you can use a click function to detect when the click happens and if its checked or not, then you can add a class or remove a class as necessary...

How can I style an Android Switch?

You can define the drawables that are used for the background, and the switcher part like this:

<Switch
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:thumb="@drawable/switch_thumb"
    android:track="@drawable/switch_bg" />

Now you need to create a selector that defines the different states for the switcher drawable. Here the copies from the Android sources:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_enabled="false" android:drawable="@drawable/switch_thumb_disabled_holo_light" />
    <item android:state_pressed="true"  android:drawable="@drawable/switch_thumb_pressed_holo_light" />
    <item android:state_checked="true"  android:drawable="@drawable/switch_thumb_activated_holo_light" />
    <item                               android:drawable="@drawable/switch_thumb_holo_light" />
</selector>

This defines the thumb drawable, the image that is moved over the background. There are four ninepatch images used for the slider:

The deactivated version (xhdpi version that Android is using)The deactivated version
The pressed slider: The pressed slider
The activated slider (on state):The activated slider
The default version (off state): enter image description here

There are also three different states for the background that are defined in the following selector:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_enabled="false" android:drawable="@drawable/switch_bg_disabled_holo_dark" />
    <item android:state_focused="true"  android:drawable="@drawable/switch_bg_focused_holo_dark" />
    <item                               android:drawable="@drawable/switch_bg_holo_dark" />
</selector>

The deactivated version: The deactivated version
The focused version: The focused version
And the default version:the default version

To have a styled switch just create this two selectors, set them to your Switch View and then change the seven images to your desired style.

How to multiply a BigDecimal by an integer in Java

You have a lot of type-mismatches in your code such as trying to put an int value where BigDecimal is required. The corrected version of your code:

public class Payment
{
    BigDecimal itemCost  = BigDecimal.ZERO;
    BigDecimal totalCost = BigDecimal.ZERO;

    public BigDecimal calculateCost(int itemQuantity, BigDecimal itemPrice)
    {
        itemCost  = itemPrice.multiply(new BigDecimal(itemQuantity));
        totalCost = totalCost.add(itemCost);
        return totalCost;
    }
}

SELECT only rows that contain only alphanumeric characters in MySQL

Your statement matches any string that contains a letter or digit anywhere, even if it contains other non-alphanumeric characters. Try this:

SELECT * FROM table WHERE column REGEXP '^[A-Za-z0-9]+$';

^ and $ require the entire string to match rather than just any portion of it, and + looks for 1 or more alphanumberic characters.

You could also use a named character class if you prefer:

SELECT * FROM table WHERE column REGEXP '^[[:alnum:]]+$';

How do I get the output of a shell command executed using into a variable from Jenkinsfile (groovy)?

quick answer is this:

sh "ls -l > commandResult"
result = readFile('commandResult').trim()

I think there exist a feature request to be able to get the result of sh step, but as far as I know, currently there is no other option.

EDIT: JENKINS-26133

EDIT2: Not quite sure since what version, but sh/bat steps now can return the std output, simply:

def output = sh returnStdout: true, script: 'ls -l'

How to Validate a DateTime in C#?

A problem with using DateTime.TryParse is that it doesn't support the very common data-entry use case of dates entered without separators, e.g. 011508.

Here's an example of how to support this. (This is from a framework I'm building, so its signature is a little weird, but the core logic should be usable):

    private static readonly Regex ShortDate = new Regex(@"^\d{6}$");
    private static readonly Regex LongDate = new Regex(@"^\d{8}$");

    public object Parse(object value, out string message)
    {
        msg = null;
        string s = value.ToString().Trim();
        if (s.Trim() == "")
        {
            return null;
        }
        else
        {
            if (ShortDate.Match(s).Success)
            {
                s = s.Substring(0, 2) + "/" + s.Substring(2, 2) + "/" + s.Substring(4, 2);
            }
            if (LongDate.Match(s).Success)
            {
                s = s.Substring(0, 2) + "/" + s.Substring(2, 2) + "/" + s.Substring(4, 4);
            }
            DateTime d = DateTime.MinValue;
            if (DateTime.TryParse(s, out d))
            {
                return d;
            }
            else
            {
                message = String.Format("\"{0}\" is not a valid date.", s);
                return null;
            }
        }

    }

Java collections convert a string to a list of characters

List<String> result = Arrays.asList("abc".split(""));

How to change the color of header bar and address bar in newest Chrome version on Lollipop?

You actually need 3 meta tags to support Android, iPhone and Windows Phone

<!-- Chrome, Firefox OS and Opera -->
<meta name="theme-color" content="#4285f4">
<!-- Windows Phone -->
<meta name="msapplication-navbutton-color" content="#4285f4">
<!-- iOS Safari -->
<meta name="apple-mobile-web-app-status-bar-style" content="#4285f4">

PHP php_network_getaddresses: getaddrinfo failed: No such host is known

A weird thing I found was that the environment variable SYSTEMROOT must be set otherwise getaddrinfo() will fail on Windows 10.

Checking whether the pip is installed?

Use command line and not python.
TLDR; On Windows, do:
python -m pip --version
OR
py -m pip --version

Details:

On Windows, ~> (open windows terminal)
Start (or Windows Key) > type "cmd" Press Enter
You should see a screen that looks like this enter image description here
To check to see if pip is installed.

python -m pip --version

if pip is installed, go ahead and use it. for example:

Z:\>python -m pip install selenium

if not installed, install pip, and you may need to
add its path to the environment variables.
(basic - windows)
add path to environment variables (basic+advanced)

if python is NOT installed you will get a result similar to the one below

enter image description here

Install python. add its path to environment variables.

UPDATE: for newer versions of python replace "python" with py - see @gimmegimme's comment and link https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/

Fail during installation of Pillow (Python module) in Linux

There is a bug reported for Pillow here, which indicates that libjpeg and zlib are now required as of Pillow 3.0.0.

The installation instructions for Pillow on Linux give advice of how to install these packages. Note that not all of the following packages may be missing on your machine (comments suggest that only libjpeg8-dev is actually missing).

pip / PyPi (Pillow>3.4.2)

The latest releases of Pillow are available on PyPi as wheels — the new standard packaging mechanism for Python. These prebuilt packages include all neccessary binary dependencies to allow Pillow to run and should be used if you want to install Pillow using PyPi

To use wheels, you need to have a version of pip>=1.4. If you are using an earlier version (pip --version) upgrade pip using the following:

pip install --upgrade pip 

Once pip is upgraded, pip install will use platform-specific wheel files by default if they are available. Use the following command to upgrade Pillow to the latest version available on PyPi:

pip install --upgrade pillow

Ubuntu 12.04 LTS or Raspian Wheezy 7.0

sudo apt-get install libtiff4-dev libjpeg8-dev zlib1g-dev libfreetype6-dev liblcms2-dev libwebp-dev tcl8.5-dev tk8.5-dev python-tk

Ubuntu 14.04

sudo apt-get install libtiff5-dev libjpeg8-dev zlib1g-dev libfreetype6-dev liblcms2-dev libwebp-dev tcl8.6-dev tk8.6-dev python-tk

Ubuntu 18.04

sudo apt install libjpeg8-dev zlib1g-dev

Fedora 20

The Fedora 20 equivalent of libjpeg8-dev is libjpeg-devel.

sudo yum install libtiff-devel libjpeg-devel libzip-devel freetype-devel lcms2-devel libwebp-devel tcl-devel tk-devel

Mac OS X (via Homebrew)

On Mac OS X with Homebrew this can be fixed using:

brew install libjpeg zlib

You may also need to force-link zlib using the following:

brew link zlib --force

Update April 2019: In Mojave the above will not work and you need to run the following as taken from this bug report on Pillow

sudo installer -pkg /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg -target /

Update July 2016: There is no longer a formula for zlib available in the main repository (Homebrew will prompt you to install lzlib which is a different library and will not solve this problem).

There is a formula available in the dupes repository. You can either tap this repository, and install as normal:

brew tap homebrew/dupes
brew install zlib

Or you can install zlib via xcode instead, as follows:

xcode-select --install

Thanks to phoenix, Panos Angelopoulou, nelsonvarela, benjaminz and Kal in the comments

After these are installed the pip installation of Pillow should work normally.

How to use bootstrap datepicker

Just add this below JS file

<script type="text/javascript">
    $(document).ready(function () {
        $('your input's id or class with # or .').datepicker({
            format: "dd/mm/yyyy"
        });
    });
</script>

How can I change image tintColor in iOS and WatchKit

With iOS 13 and above, you can simply use

let image = UIImage(named: "Heart")?.withRenderingMode(.alwaysTemplate)
if #available(iOS 13.0, *) {
   imageView.image = image?.withTintColor(UIColor.white)
}

Printing all properties in a Javascript Object

What about this:

var txt="";
var nyc = {
    fullName: "New York City",
    mayor: "Michael Bloomberg",
    population: 8000000,
    boroughs: 5
};

for (var x in nyc){
    txt += nyc[x];
}

How to get the HTML's input element of "file" type to only accept pdf files?

The previous posters made a little mistake. The accept attribute is only a display filter. It will not validate your entry before submitting.

This attribute forces the file dialog to display the required mime type only. But the user can override that filter. He can choose . and see all the files in the current directory. By doing so, he can select any file with any extension, and submit the form.

So, to answer to the original poster, NO. You cannot restrict the input file to one particular extension by using HTML.

But you can use javascript to test the filename that has been chosen, just before submitting. Just insert an onclick attribute on your submit button and call the code that will test the input file value. If the extension is forbidden, you'll have to return false to invalidate the form. You may even use a jQuery custom validator and so on, to validate the form.

Finally, you'll have to test the extension on the server side too. Same problem about the maximum allowed file size.

C++ "Access violation reading location" Error

You haven't posted the findvertex method, but Access Reading Violation with an offset like 0x00000048 means that the Vertex* f; in your getCost function is receiving null, and when trying to access the member adj in the null Vertex pointer (that is, in f), it is offsetting to adj (in this case, 72 bytes ( 0x48 bytes in decimal )), it's reading near the 0 or null memory address.

Doing a read like this violates Operating-System protected memory, and more importantly means whatever you're pointing at isn't a valid pointer. Make sure findvertex isn't returning null, or do a comparisong for null on f before using it to keep yourself sane (or use an assert):

assert( f != null ); // A good sanity check

EDIT:

If you have a map for doing something like a find, you can just use the map's find method to make sure the vertex exists:

Vertex* Graph::findvertex(string s)
{
    vmap::iterator itr = map1.find( s );
    if ( itr == map1.end() )
    {
        return NULL;
    }
    return itr->second;
}

Just make sure you're still careful to handle the error case where it does return NULL. Otherwise, you'll keep getting this access violation.

How to find the last day of the month from date?

You could create a date for the first of the next month, and then use strtotime("-1 day", $firstOfNextMonth)

Difference between return 1, return 0, return -1 and exit?

To indicate execution status.

status 0 means the program succeeded.

status different from 0 means the program exited due to error or anomaly.

return n; from your main entry function will terminate your process and report to the parent process (the one that executed your process) the result of your process. 0 means SUCCESS. Other codes usually indicates a failure and its meaning.

What is a typedef enum in Objective-C?

An enum declares a set of ordered values - the typedef just adds a handy name to this. The 1st element is 0 etc.

typedef enum {
Monday=1,
...
} WORKDAYS;

WORKDAYS today = Monday;

The above is just an enumeration of shapeType tags.

Nginx location "not equal to" regex

According to nginx documentation

there is no syntax for NOT matching a regular expression. Instead, match the target regular expression and assign an empty block, then use location / to match anything else

So you could define something like

location ~ (dir1|file2\.php) { 
    # empty
}

location / {
    rewrite ^/(.*) http://example.com/$1 permanent; 
}

Inheriting constructors

Constructors are not inherited. They are called implicitly or explicitly by the child constructor.

The compiler creates a default constructor (one with no arguments) and a default copy constructor (one with an argument which is a reference to the same type). But if you want a constructor that will accept an int, you have to define it explicitly.

class A
{
public: 
    explicit A(int x) {}
};

class B: public A
{
public:
    explicit B(int x) : A(x) { }
};

UPDATE: In C++11, constructors can be inherited. See Suma's answer for details.

React-Native: Module AppRegistry is not a registered callable module

I got this error in Expo because I had exported the wrong component name, e.g.

const Wonk = props => (
  <Text>Hi!</Text>
)

export default Stack;

count number of lines in terminal output

"abcd4yyyy" | grep 4 -c gives the count as 1

Convert DataTable to List<T>

The following does it in a single line:

dataTable.Rows.OfType<DataRow>()
    .Select(dr => dr.Field<MyType>(columnName)).ToList();

[Edit: Add a reference to System.Data.DataSetExtensions to your project if this does not compile]

Reading file from Workspace in Jenkins with Groovy script

Based on your comments, you would be better off with Text-finder plugin.

It allows to search file(s), as well as console, for a regular expression and then set the build either unstable or failed if found.

As for the Groovy, you can use the following to access ${WORKSPACE} environment variable:
def workspace = manager.build.getEnvVars()["WORKSPACE"]

PHP preg replace only allow numbers

Try this:

return preg_replace("/[^0-9]/", "",$c);

How to convert a color integer to a hex String in Android?

Integer value of ARGB color to hexadecimal string:

String hex = Integer.toHexString(color); // example for green color FF00FF00

Hexadecimal string to integer value of ARGB color:

int color = (Integer.parseInt( hex.substring( 0,2 ), 16) << 24) + Integer.parseInt( hex.substring( 2 ), 16);

How can I make a JPA OneToOne relation lazy

In native Hibernate XML mappings, you can accomplish this by declaring a one-to-one mapping with the constrained attribute set to true. I am not sure what the Hibernate/JPA annotation equivalent of that is, and a quick search of the doc provided no answer, but hopefully that gives you a lead to go on.

How do I get some variable from another class in Java?

Your example is perfect: the field is private and it has a getter. This is the normal way to access a field. If you need a direct access to an object field, use reflection. Using reflection to get a field's value is a hack and should be used in extreme cases such as using a library whose code you cannot change.

Eclipse: Error ".. overlaps the location of another project.." when trying to create new project

simply "CUT" project folder and move it out of workspace directory and do the following

file=>import=>(select new directory)=> mark (copy to my workspace) checkbox 

and you done !

What determines the monitor my app runs on?

Do not hold me to this but I am pretty sure it depends on the application it self. I know many always open on the main monitor, some will reopen to the same monitor they were previously run in, and some you can set. I know for example I have shortcuts to open command windows to particular directories, and each has an option in their properties to the location to open the window in. While Outlook just remembers and opens in the last screen it was open in. Then other apps open in what ever window the current focus is in.

So I am not sure there is a way to tell every program where to open. Hope that helps some.

Remove characters from a String in Java

String id = id.substring(0,id.length()-4)

Session 'app': Error Installing APK

In my case with Android 8.0(Oreo), no one of this solutions worked! If you have more than 1 user, then you should go to Settings->Applications->All Applications->Find the application and uninstall for all users! After this steps, it worked!

Simplest way to restart service on a remote computer

DESCRIPTION: SC is a command line program used for communicating with the NT Service Controller and services. USAGE: sc [command] [service name] ...

    The option <server> has the form "\\ServerName"
    Further help on commands can be obtained by typing: "sc [command]"
    Commands:
      query-----------Queries the status for a service, or
                      enumerates the status for types of services.
      queryex---------Queries the extended status for a service, or
                      enumerates the status for types of services.
      start-----------Starts a service.
      pause-----------Sends a PAUSE control request to a service.
      interrogate-----Sends an INTERROGATE control request to a service.
      continue--------Sends a CONTINUE control request to a service.
      stop------------Sends a STOP request to a service.
      config----------Changes the configuration of a service (persistant).
      description-----Changes the description of a service.
      failure---------Changes the actions taken by a service upon failure.
      qc--------------Queries the configuration information for a service.
      qdescription----Queries the description for a service.
      qfailure--------Queries the actions taken by a service upon failure.
      delete----------Deletes a service (from the registry).
      create----------Creates a service. (adds it to the registry).
      control---------Sends a control to a service.
      sdshow----------Displays a service's security descriptor.
      sdset-----------Sets a service's security descriptor.
      GetDisplayName--Gets the DisplayName for a service.
      GetKeyName------Gets the ServiceKeyName for a service.
      EnumDepend------Enumerates Service Dependencies.

    The following commands don't require a service name:
    sc <server> <command> <option>
      boot------------(ok | bad) Indicates whether the last boot should
                      be saved as the last-known-good boot configuration
      Lock------------Locks the Service Database
      QueryLock-------Queries the LockStatus for the SCManager Database

EXAMPLE: sc start MyService

A potentially dangerous Request.Path value was detected from the client (*)

If you're using .NET 4.0 you should be able to allow these urls via the web.config

<system.web>
    <httpRuntime 
            requestPathInvalidCharacters="&lt;,&gt;,%,&amp;,:,\,?" />
</system.web>

Note, I've just removed the asterisk (*), the original default string is:

<httpRuntime 
          requestPathInvalidCharacters="&lt;,&gt;,*,%,&amp;,:,\,?" />

See this question for more details.

Matplotlib-Animation "No MovieWriters Available"

Had the same problem....managed to get it to work after a little while.

Thing to do is follow instructions on installing FFmpeg - which is (at least on windows) a bundle of executables you need to set a path to in your environment variables

http://www.wikihow.com/Install-FFmpeg-on-Windows

Download from ffmpeg.org

Hope this helps someone - even after a while after the question - good luck

How do I correctly detect orientation change using Phonegap on iOS?

I'm pretty new to iOS and Phonegap as well, but I was able to do this by adding in an eventListener. I did the same thing (using the example you reference), and couldn't get it to work. But this seemed to do the trick:

// Event listener to determine change (horizontal/portrait)
window.addEventListener("orientationchange", updateOrientation); 

function updateOrientation(e) {
switch (e.orientation)
{   
    case 0:
        // Do your thing
        break;

    case -90:
        // Do your thing
        break;

    case 90:
        // Do your thing
        break;

    default:
        break;
    }
}

You may have some luck searching the PhoneGap Google Group for the term "orientation".

One example I read about as an example on how to detect orientation was Pie Guy: (game, js file). It's similar to the code you've posted, but like you... I couldn't get it to work.

One caveat: the eventListener worked for me, but I'm not sure if this is an overly intensive approach. So far it's been the only way that's worked for me, but I don't know if there are better, more streamlined ways.


UPDATE fixed the code above, it works now

How can I show a hidden div when a select option is selected?

Try handling the change event of the select and using this.value to determine whether it's 'Yes' or not.

jsFiddle

JS

document.getElementById('test').addEventListener('change', function () {
    var style = this.value == 1 ? 'block' : 'none';
    document.getElementById('hidden_div').style.display = style;
});

HTML

<select id="test" name="form_select">
   <option value="0">No</option>
   <option value ="1">Yes</option>
</select>

<div id="hidden_div" style="display: none;">Hello hidden content</div>

"Char cannot be dereferenced" error

I guess ch is a declared as char. Since char is a primitive data type and not and object, you can't call any methof from it. You should use Character.isLetter(ch).

How to call execl() in C with the proper arguments?

If you need just to execute your VLC playback process and only give control back to your application process when it is done and nothing more complex, then i suppose you can use just:

system("The same thing you type into console");

There is already an open DataReader associated with this Command which must be closed first

Well for me it was my own bug. I was trying to run an INSERT using SqlCommand.executeReader() when I should have been using SqlCommand.ExecuteNonQuery(). It was opened and never closed, causing the error. Watch out for this oversight.

SQL Column definition : default value and not null redundant?

I would say not.

If the column does accept null values, then there's nothing to stop you inserting a null value into the field. As far as I'm aware, the default value only applies on creation of a new row.

With not null set, then you can't insert a null value into the field as it'll throw an error.

Think of it as a fail safe mechanism to prevent nulls.

How to cd into a directory with space in the name?

To change to a directory with spaces on the name you just have to type like this:

cd My\ Documents

Hit enter and you will be good

Eclipse: "'Periodic workspace save.' has encountered a pro?blem."

I fixed mine by closing eclipse and deleting the whole .metadata folder inside my workspace folder.

Common CSS Media Queries Break Points

Rather than try to target @media rules at specific devices, it is arguably more practical to base them on your particular layout instead. That is, gradually narrow your desktop browser window and observe the natural breakpoints for your content. It's different for every site. As long as the design flows well at each browser width, it should work pretty reliably on any screen size (and there are lots and lots of them out there.)

What is an MDF file?

Just to make this absolutely clear for all:

A .MDF file is “typically” a SQL Server data file however it is important to note that it does NOT have to be.

This is because .MDF is nothing more than a recommended/preferred notation but the extension itself does not actually dictate the file type.

To illustrate this, if someone wanted to create their primary data file with an extension of .gbn they could go ahead and do so without issue.

To qualify the preferred naming conventions:

  • .mdf - Primary database data file.
  • .ndf - Other database data files i.e. non Primary.
  • .ldf - Log data file.

Language Books/Tutorials for popular languages

Ruby

Simple PHP Pagination script

Some of the tutorials I found that are easy to understand are:

It makes way more sense to break up your list into page-sized chunks, and only query your database one chunk at a time. This drastically reduces server processing time and page load time, as well as gives your user smaller pieces of info to digest, so he doesn't choke on whatever crap you're trying to feed him. The act of doing this is called pagination.

A basic pagination routine seems long and scary at first, but once you close your eyes, take a deep breath, and look at each piece of the script individually, you will find it's actually pretty easy stuff

The script:

// find out how many rows are in the table 
$sql = "SELECT COUNT(*) FROM numbers";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);
$r = mysql_fetch_row($result);
$numrows = $r[0];

// number of rows to show per page
$rowsperpage = 10;
// find out total pages
$totalpages = ceil($numrows / $rowsperpage);

// get the current page or set a default
if (isset($_GET['currentpage']) && is_numeric($_GET['currentpage'])) {
   // cast var as int
   $currentpage = (int) $_GET['currentpage'];
} else {
   // default page num
   $currentpage = 1;
} // end if

// if current page is greater than total pages...
if ($currentpage > $totalpages) {
   // set current page to last page
   $currentpage = $totalpages;
} // end if
// if current page is less than first page...
if ($currentpage < 1) {
   // set current page to first page
   $currentpage = 1;
} // end if

// the offset of the list, based on current page 
$offset = ($currentpage - 1) * $rowsperpage;

// get the info from the db 
$sql = "SELECT id, number FROM numbers LIMIT $offset, $rowsperpage";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);

// while there are rows to be fetched...
while ($list = mysql_fetch_assoc($result)) {
   // echo data
   echo $list['id'] . " : " . $list['number'] . "<br />";
} // end while

/******  build the pagination links ******/
// range of num links to show
$range = 3;

// if not on page 1, don't show back links
if ($currentpage > 1) {
   // show << link to go back to page 1
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=1'><<</a> ";
   // get previous page num
   $prevpage = $currentpage - 1;
   // show < link to go back to 1 page
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$prevpage'><</a> ";
} // end if 

// loop to show links to range of pages around current page
for ($x = ($currentpage - $range); $x < (($currentpage + $range) + 1); $x++) {
   // if it's a valid page number...
   if (($x > 0) && ($x <= $totalpages)) {
      // if we're on current page...
      if ($x == $currentpage) {
         // 'highlight' it but don't make a link
         echo " [<b>$x</b>] ";
      // if not current page...
      } else {
         // make it a link
         echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$x'>$x</a> ";
      } // end else
   } // end if 
} // end for

// if not on last page, show forward and last page links        
if ($currentpage != $totalpages) {
   // get next page
   $nextpage = $currentpage + 1;
    // echo forward link for next page 
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$nextpage'>></a> ";
   // echo forward link for lastpage
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$totalpages'>>></a> ";
} // end if
/****** end build pagination links ******/
?>

This tutorial is intended for developers who wish to give their users the ability to step through a large number of database rows in manageable chunks instead of the whole lot in one go.

CSS no text wrap

Additionally to overflow:hidden, use

white-space:nowrap;

MySQL "Group By" and "Order By"

A simple solution is to wrap the query into a subselect with the ORDER statement first and applying the GROUP BY later:

SELECT * FROM ( 
    SELECT `timestamp`, `fromEmail`, `subject`
    FROM `incomingEmails` 
    ORDER BY `timestamp` DESC
) AS tmp_table GROUP BY LOWER(`fromEmail`)

This is similar to using the join but looks much nicer.

Using non-aggregate columns in a SELECT with a GROUP BY clause is non-standard. MySQL will generally return the values of the first row it finds and discard the rest. Any ORDER BY clauses will only apply to the returned column value, not to the discarded ones.

IMPORTANT UPDATE Selecting non-aggregate columns used to work in practice but should not be relied upon. Per the MySQL documentation "this is useful primarily when all values in each nonaggregated column not named in the GROUP BY are the same for each group. The server is free to choose any value from each group, so unless they are the same, the values chosen are indeterminate."

As of 5.7.5 ONLY_FULL_GROUP_BY is enabled by default so non-aggregate columns cause query errors (ER_WRONG_FIELD_WITH_GROUP)

As @mikep points out below the solution is to use ANY_VALUE() from 5.7 and above

See http://www.cafewebmaster.com/mysql-order-sort-group https://dev.mysql.com/doc/refman/5.6/en/group-by-handling.html https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_any-value

Oracle's default date format is YYYY-MM-DD, WHY?

If you are using this query to generate an input file for your Data Warehouse, then you need to format the data appropriately. Essentially in that case you are converting the date (which does have a time component) to a string. You need to explicitly format your string or change your nls_date_format to set the default. In your query you could simply do:

select to_char(some_date, 'yyyy-mm-dd hh24:mi:ss') my_date
  from some_table;

In python, what is the difference between random.uniform() and random.random()?

The difference is in the arguments. It's very common to generate a random number from a uniform distribution in the range [0.0, 1.0), so random.random() just does this. Use random.uniform(a, b) to specify a different range.

Relative imports - ModuleNotFoundError: No module named x

For me, simply adding the current directory worked.

Using the following structure:

+-- myproject
    +-- a.py
    +-- b.py

a.py:

from b import some_object
# returns ModuleNotFound error

from myproject.b import some_object
# works

PostgreSQL: Modify OWNER on all tables simultaneously in PostgreSQL

This: http://archives.postgresql.org/pgsql-bugs/2007-10/msg00234.php is also a nice and fast solution, and works for multiple schemas in one database:

Tables

SELECT 'ALTER TABLE '|| schemaname || '."' || tablename ||'" OWNER TO my_new_owner;'
FROM pg_tables WHERE NOT schemaname IN ('pg_catalog', 'information_schema')
ORDER BY schemaname, tablename;

Sequences

SELECT 'ALTER SEQUENCE '|| sequence_schema || '."' || sequence_name ||'" OWNER TO my_new_owner;'
FROM information_schema.sequences WHERE NOT sequence_schema IN ('pg_catalog', 'information_schema')
ORDER BY sequence_schema, sequence_name;

Views

SELECT 'ALTER VIEW '|| table_schema || '."' || table_name ||'" OWNER TO my_new_owner;'
FROM information_schema.views WHERE NOT table_schema IN ('pg_catalog', 'information_schema')
ORDER BY table_schema, table_name;

Materialized Views

Based on this answer

SELECT 'ALTER TABLE '|| oid::regclass::text ||' OWNER TO my_new_owner;'
FROM pg_class WHERE relkind = 'm'
ORDER BY oid;

This generates all the required ALTER TABLE / ALTER SEQUENCE / ALTER VIEW statements, copy these and paste them back into plsql to run them.

Check your work in psql by doing:

\dt *.*
\ds *.*
\dv *.*

How to search images from private 1.0 registry in docker?

Modifying the answer from @mre to get the list just from one command (valid at least for Docker Registry v2).

docker exec -it <your_registry_container_id> ls -a /var/lib/registry/docker/registry/v2/repositories/

Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed

It may be that the Windows Credential Manager is holding onto credentials for the network share.

Credential Manager - Windows Credentials

Load up Credential Manager (the easiest way is perhaps just to Search for that in the Start Menu), see if there are any Windows Credentials for your network share, and try deleting/updating them.

What are "named tuples" in Python?

Another way (a new way) to use named tuple is using NamedTuple from typing package: Type hints in namedtuple

Let's use the example of the top answer in this post to see how to use it.

(1) Before using the named tuple, the code is like this:

pt1 = (1.0, 5.0)
pt2 = (2.5, 1.5)

from math import sqrt

line_length = sqrt((pt1[0] - pt2[0])**2 + (pt1[1] - pt2[1])**2)
print(line_length)

(2) Now we use the named tuple

from typing import NamedTuple

inherit the NamedTuple class and define the variable name in the new class. test is the name of the class.

class test(NamedTuple):
    x: float
    y: float

create instances from the class and assign values to them

pt1 = test(1.0, 5.0)   # x is 1.0, and y is 5.0. The order matters
pt2 = test(2.5, 1.5)

use the variables from the instances to calculate

line_length = sqrt((pt1.x - pt2.x)**2 + (pt1.y - pt2.y)**2)
print(line_length)

How can I view array structure in JavaScript with alert()?

If what you want is to show with an alert() the content of an array of objects, i recomend you to define in the object the method toString() so with a simple alert(MyArray); the full content of the array will be shown in the alert.

Here is an example:

//-------------------------------------------------------------------
// Defininf the Point object
function Point(CoordenadaX, CoordenadaY) {
    // Sets the point coordinates depending on the parameters defined
    switch (arguments.length) {
        case 0:
            this.x = null;
            this.y = null;
            break;
        case 1:
            this.x = CoordenadaX;
            this.y = null;
            break;
        case 2:
            this.x = CoordenadaX;
            this.y = CoordenadaY;
            break;
    }
    // This adds the toString Method to the point object so the 
    // point can be printed using alert();
    this.toString = function() {
        return " (" + this.x + "," + this.y + ") ";
    };
 }

Then if you have an array of points:

var MyArray = [];
MyArray.push ( new Point(5,6) );
MyArray.push ( new Point(7,9) );

You can print simply calling:

alert(MyArray);

Hope this helps!

Copy all the lines to clipboard

If your fingers default to CTRL-A CTRL-C, then try the mappings from $VIMRUNTIME/mswin.vim.

" CTRL-C and CTRL-Insert are Copy
vnoremap <C-C> "+y

" CTRL-A is Select all
noremap <C-A> gggH<C-O>G
inoremap <C-A> <C-O>gg<C-O>gH<C-O>G
cnoremap <C-A> <C-C>gggH<C-O>G
onoremap <C-A> <C-C>gggH<C-O>G
snoremap <C-A> <C-C>gggH<C-O>G
xnoremap <C-A> <C-C>ggVG

I have them mapped to <Leader><C-a> and <Leader><C-c>.

How to append in a json file in Python?

You need to update the output of json.load with a_dict and then dump the result. And you cannot append to the file but you need to overwrite it.

Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack

Resolution

To work around this problem, use one of the following methods:

Symptoms

If you use the Response.End, Response.Redirect, or Server.Transfer method, a ThreadAbortException exception occurs. You can use a try-catch statement to catch this exception.

Cause

The Response.End method ends the page execution and shifts the execution to the Application_EndRequest event in the application's event pipeline. The line of code that follows Response.End is not executed.

This problem occurs in the Response.Redirect and Server.Transfer methods because both methods call Response.End internally.

Status

This behavior is by design.

Properties

Article ID: 312629 - Last Review: August 30, 2012 - Revision: 4.0

Applies to

  • Microsoft ASP.NET 4.5
  • Microsoft ASP.NET 4
  • Microsoft ASP.NET 3.5
  • Microsoft ASP.NET 2.0
  • Microsoft ASP.NET 1.1
  • Microsoft ASP.NET 1.0

Keywords: kbexcepthandling kbprb KB312629

Source: PRB: ThreadAbortException Occurs If You Use Response.End, Response.Redirect, or Server.Transfer

How can I get column names from a table in Oracle?

select column_name,* from information_schema.columns
 where table_name = 'YourTableName'
order by ordinal_position

When to use std::size_t?

A good rule of thumb is for anything that you need to compare in the loop condition against something that is naturally a std::size_t itself.

std::size_t is the type of any sizeof expression and as is guaranteed to be able to express the maximum size of any object (including any array) in C++. By extension it is also guaranteed to be big enough for any array index so it is a natural type for a loop by index over an array.

If you are just counting up to a number then it may be more natural to use either the type of the variable that holds that number or an int or unsigned int (if large enough) as these should be a natural size for the machine.

Python convert set to string and vice versa

Try like this,

>>> s = set([1,2,3])
>>> s = list(s)
>>> s
[1, 2, 3]

>>> str = ', '.join(str(e) for e in s)
>>> str = 'set(%s)' % str
>>> str
'set(1, 2, 3)'

How to choose the id generation strategy when using JPA and Hibernate


A while ago i wrote a detailed article about Hibernate key generators: http://blog.eyallupu.com/2011/01/hibernatejpa-identity-generators.html

Choosing the correct generator is a complicated task but it is important to try and get it right as soon as possible - a late migration might be a nightmare.

A little off topic but a good chance to raise a point usually overlooked which is sharing keys between applications (via API). Personally I always prefer surrogate keys and if I need to communicate my objects with other systems I don't expose my key (even though it is a surrogate one) – I use an additional ‘external key’. As a consultant I have seen more than once 'great' system integrations using object keys (the 'it is there let's just use it' approach) just to find a year or two later that one side has issues with the key range or something of the kind requiring a deep migration on the system exposing its internal keys. Exposing your key means exposing a fundamental aspect of your code to external constrains shouldn’t really be exposed to.

C#: How would I get the current time into a string?

You can use format strings as well.

string time = DateTime.Now.ToString("hh:mm:ss"); // includes leading zeros
string date = DateTime.Now.ToString("dd/MM/yy"); // includes leading zeros

or some shortcuts if the format works for you

string time = DateTime.Now.ToShortTimeString();
string date = DateTime.Now.ToShortDateString();

Either should work.

Session 'app' error while installing APK

Look at screenshot

Here is gradle console updates:

5:01 PM Gradle build finished in 1s 252ms

5:13 PM Executing tasks: [:app:assembleDebug]

5:13 PM Gradle build finished with 15 error(s) in 1s 125ms

5:15 PM Executing tasks: [:app:assembleDebug]

5:15 PM Gradle build finished with 13 error(s) in 1s 608ms

5:16 PM Executing tasks: [:app:assembleDebug]

Difference between .on('click') vs .click()

.click events only work when element gets rendered and are only attached to elements loaded when the DOM is ready.

.on events are dynamically attached to DOM elements, which is helpful when you want to attach an event to DOM elements that are rendered on ajax request or something else (after the DOM is ready).

Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing

you could use binary search to find intervals of missing (or contiguous) numbers. The run time should be around (num intervals) * log(avg interval length) * N. Useful if there aren't many intervals.

SQL Server: How to use UNION with two queries that BOTH have a WHERE clause?

Notice that each SELECT statement within the UNION must have the same number of columns. The columns must also have similar data types. Also, the columns in each SELECT statement must be in the same order. you are selecting

t1.ID, t2.ReceivedDate from Table t1

union

t2.ID from Table t2

which is incorrect.

so you have to write

t1.ID, t1.ReceivedDate from Table t1 union t2.ID, t2.ReceivedDate from Table t1

you can use sub query here

 SELECT tbl1.ID, tbl1.ReceivedDate FROM
      (select top 2 t1.ID, t1.ReceivedDate
      from tbl1 t1
      where t1.ItemType = 'TYPE_1'
      order by ReceivedDate desc
      ) tbl1 
 union
    SELECT tbl2.ID, tbl2.ReceivedDate FROM
     (select top 2 t2.ID, t2.ReceivedDate
      from tbl2 t2
      where t2.ItemType = 'TYPE_2'
      order by t2.ReceivedDate desc
     ) tbl2 

so it will return only distinct values by default from both table.

Android Studio-No Module

Try first in Android Studio:

File -> Sync Project with Gradle Files

What's the difference between SHA and AES encryption?

SHA doesn't require anything but an input to be applied, while AES requires at least 3 things - what you're encrypting/decrypting, an encryption key, and the initialization vector.

Centering the image in Bootstrap

.img-responsive {
     margin: 0 auto;
 }

you can write like above code in your document so no need to add one another class in image tag.

Best way to get value from Collection by index

use for each loop...

ArrayList<Character> al = new ArrayList<>();    
String input="hello";

for (int i = 0; i < input.length(); i++){
    al.add(input.charAt(i));
}

for (Character ch : al) {               
    System.Out.println(ch);             
}

How do you create a REST client for Java?

You can also check Restlet which has full client-side capabilities, more REST oriented that lower-level libraries such as HttpURLConnection or Apache HTTP Client (which we can leverage as connectors).

Best regards, Jerome Louvel

What characters can be used for up/down triangle (arrow without stem) for display in HTML?

A lot of people here are suggesting to use the triangles, but sometimes you need a chevron.

We had a case where our button shows a chevron, and wanted the user's manual to refer to the button in a way which will be recognized by a non-technical user too. So we needed a chevron sign.

We used ? in the end. It is known as PRESENTATION FORM FOR VERTICAL RIGHT ANGLE BRACKET and its code is U+FE40.

What does request.getParameter return?

Both if (one.length() > 0) {} and if (!"".equals(one)) {} will check against an empty foo parameter, and an empty parameter is what you'd get if the the form is submitted with no value in the foo text field.

If there's any chance you can use the Expression Language to handle the parameter, you could access it with empty param.foo in an expression.

<c:if test='${not empty param.foo}'>
    This page code gets rendered.
</c:if>

Reset the database (purge all), then seed a database

As of Rails 5, the rake commandline tool has been aliased as rails so now

rails db:reset instead of rake db:reset

will work just as well

Difference between chr(13) and chr(10)

Chr(10) is the Line Feed character and Chr(13) is the Carriage Return character.

You probably won't notice a difference if you use only one or the other, but you might find yourself in a situation where the output doesn't show properly with only one or the other. So it's safer to include both.


Historically, Line Feed would move down a line but not return to column 1:

This  
    is  
        a  
            test.

Similarly Carriage Return would return to column 1 but not move down a line:

This  
is  
a  
test.

Paste this into a text editor and then choose to "show all characters", and you'll see both characters present at the end of each line. Better safe than sorry.

Java - Check Not Null/Empty else assign default value

In Java 9, if you have an object which has another object as property and that nested objects has a method yielding a string, then you can use this construct to return an empty string if the embeded object is null :

String label = Optional.ofNullable(org.getDiffusion()).map(Diffusion::getLabel).orElse("")

In this example :

  • org is an instance of an object of type Organism
  • Organism has a Diffusion property (another object)
  • Diffusion has a String label property (and getLabel() getter).

With this example, if org.getDiffusion() is not null, then it returns the getLabel property of its Diffusion object (this returns a String). Otherwise, it returns an empty string.

How to PUT a json object with an array using curl

Your command line should have a -d/--data inserted before the string you want to send in the PUT, and you want to set the Content-Type and not Accept.

curl -H 'Content-Type: application/json' -X PUT -d '[JSON]' \
     http://example.com/service

Using the exact JSON data from the question, the full command line would become:

curl -H 'Content-Type: application/json' -X PUT \
    -d '{"tags":["tag1","tag2"],
         "question":"Which band?",
         "answers":[{"id":"a0","answer":"Answer1"},
                    {"id":"a1","answer":"answer2"}]}' \
    http://example.com/service

Note: JSON data wrapped only for readability, not valid for curl request.

Convert HTML + CSS to PDF

This question is pretty old already, but haven't seen anyone mentioning CutyCapt so I will :)

CutyCapt

CutyCapt is a small cross-platform command-line utility to capture WebKit's rendering of a web page into a variety of vector and bitmap formats, including SVG, PDF, PS, PNG, JPEG, TIFF, GIF, and BMP

python: after installing anaconda, how to import pandas

If you are facing same problem as mine. Here is the solution which works for me.

  1. Uninstall every python and anaconda.
  2. Download anaconda from here "http://continuum.io/downloads" and only install it (no other python is needed).
  3. Open spyder and import.
  4. If you get any error, type in command prompt

    pip install module_name

I hope it will work for you too

how to implement a long click listener on a listview

    listView.setOnLongClickListener(new View.OnLongClickListener() {
    @Override
    public boolean onLongClick(View view) {
        return false;
    }
});

Definitely does the trick.

Using Mockito to stub and execute methods for testing

SHORT ANSWER

How to do in your case:

int argument = 5; // example with int but could be another type
Mockito.when(mockMyAgent.otherMethod(Mockito.anyInt()).thenReturn(requiredReturnArg(argument));

LONG ANSWER

Actually what you want to do is possible, at least in Java 8. Maybe you didn't get this answer by other people because I am using Java 8 that allows that and this question is before release of Java 8 (that allows to pass functions, not only values to other functions).

Let's simulate a call to a DataBase query. This query returns all the rows of HotelTable that have FreeRoms = X and StarNumber = Y. What I expect during testing, is that this query will give back a List of different hotel: every returned hotel has the same value X and Y, while the other values and I will decide them according to my needs. The following example is simple but of course you can make it more complex.

So I create a function that will give back different results but all of them have FreeRoms = X and StarNumber = Y.

static List<Hotel> simulateQueryOnHotels(int availableRoomNumber, int starNumber) {
    ArrayList<Hotel> HotelArrayList = new ArrayList<>();
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Rome, 1, 1));
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Krakow, 7, 15));
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Madrid, 1, 1));
    HotelArrayList.add(new Hotel(availableRoomNumber, starNumber, Athens, 4, 1));

    return HotelArrayList;
}

Maybe Spy is better (please try), but I did this on a mocked class. Here how I do (notice the anyInt() values):

//somewhere at the beginning of your file with tests...
@Mock
private DatabaseManager mockedDatabaseManager;

//in the same file, somewhere in a test...
int availableRoomNumber = 3;
int starNumber = 4;
// in this way, the mocked queryOnHotels will return a different result according to the passed parameters
when(mockedDatabaseManager.queryOnHotels(anyInt(), anyInt())).thenReturn(simulateQueryOnHotels(availableRoomNumber, starNumber));

How to find Max Date in List<Object>?

A small improvement from the accepted answer is to do the null check and also get full object.

public class DateComparator {

public static void main(String[] args) throws ParseException {
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

    List<Employee> employees = new ArrayList<>();
    employees.add(new Employee(1, "name1", addDays(new Date(), 1)));
    employees.add(new Employee(2, "name2", addDays(new Date(), 3)));
    employees.add(new Employee(3, "name3", addDays(new Date(), 6)));
    employees.add(new Employee(4, "name4", null));
    employees.add(new Employee(5, "name5", addDays(new Date(), 4)));
    employees.add(new Employee(6, "name6", addDays(new Date(), 5)));
    System.out.println(employees);
    Date maxDate = employees.stream().filter(emp -> emp.getJoiningDate() != null).map(Employee::getJoiningDate).max(Date::compareTo).get();
    System.out.println(format.format(maxDate));
    //Comparator<Employee> comparator = (p1, p2) -> p1.getJoiningDate().compareTo(p2.getJoiningDate());
    Comparator<Employee> comparator = Comparator.comparing(Employee::getJoiningDate);
    Employee maxDatedEmploye = employees.stream().filter(emp -> emp.getJoiningDate() != null).max(comparator).get();
    System.out.println(" maxDatedEmploye : " + maxDatedEmploye);

    Employee minDatedEmployee = employees.stream().filter(emp -> emp.getJoiningDate() != null).min(comparator).get();
    System.out.println(" minDatedEmployee : " + minDatedEmployee);

}

public static Date addDays(Date date, int days) {
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    cal.add(Calendar.DATE, days); // minus number would decrement the days
    return cal.getTime();
}
}

You would get below results :

 [Employee [empId=1, empName=name1, joiningDate=Wed Mar 21 13:33:09 EDT 2018],
Employee [empId=2, empName=name2, joiningDate=Fri Mar 23 13:33:09 EDT 2018],
Employee [empId=3, empName=name3, joiningDate=Mon Mar 26 13:33:09 EDT 2018],
Employee [empId=4, empName=name4, joiningDate=null],
Employee [empId=5, empName=name5, joiningDate=Sat Mar 24 13:33:09 EDT 2018],
Employee [empId=6, empName=name6, joiningDate=Sun Mar 25 13:33:09 EDT 2018]
]
2018-03-26
 maxDatedEmploye : Employee [empId=3, empName=name3, joiningDate=Mon Mar 26 13:33:09 EDT 2018]

 minDatedEmployee : Employee [empId=1, empName=name1, joiningDate=Wed Mar 21 13:33:09 EDT 2018]

Update : What if list itself is empty ?

        Date maxDate = employees.stream().filter(emp -> emp.getJoiningDate() != null).map(Employee::getJoiningDate).max(Date::compareTo).orElse(new Date());
    System.out.println(format.format(maxDate));
    Comparator<Employee> comparator = Comparator.comparing(Employee::getJoiningDate);
    Employee maxDatedEmploye = employees.stream().filter(emp -> emp.getJoiningDate() != null).max(comparator).orElse(null);
    System.out.println(" maxDatedEmploye : " + maxDatedEmploye);

How to mount a host directory in a Docker container

you can use -v option from cli, this facility is not available via Dockerfile

docker run -t -i -v <host_dir>:<container_dir> ubuntu /bin/bash

where host_dir is the directory from host which you want to mount. you don't need to worry about directory of container if it doesn't exist docker will create it.

If you do any changes in host_dir from host machine (under root privilege) it will be visible to container and vice versa.

How to prevent "The play() request was interrupted by a call to pause()" error?

I've just published an article about this exact issue at https://developers.google.com/web/updates/2017/06/play-request-was-interrupted that tells you exactly what is happening and how to fix it.

How can I parse String to Int in an Angular expression?

You can create a Pipe and use it wherever you want in your system.

import { Pipe, PipeTransform } from '@angular/core';
 @Pipe({
     // tslint:disable-next-line:pipe-naming
     name: 'toNumber',
     pure: false }) export class ToNumberPipe implements PipeTransform { 
     public transform(items: any): any {
         if (!items) {
             return 0;
         }
         return parseInt(items, 10);
     } }

In the HTML

{{ attr.text | toNumber }}

Remember to declare this Pipe to be accessfull in your modules file.

How to change sa password in SQL Server 2008 express?

This may help you to reset your sa password for SQL 2008 and 2012

EXEC sp_password NULL, 'yourpassword', 'sa'

Accessing a local website from another computer inside the local network in IIS 7

Find the local IP address of computer A and find the port that your website is running on. Then from computer B open a web browser and go to IP:port. Example: 192.168.1.5:80 if computer A's IP is 192.168.1.5 and your website is running on port 80

Cast Object to Generic Type for returning

I stumble upon this question and it grabbed my interest. The accepted answer is completely correct, but I thought I do provide my findings at JVM byte code level to explain why the OP encounter the ClassCastException.

I have the code which is pretty much the same as OP's code:

public static <T> T convertInstanceOfObject(Object o) {
    try {
       return (T) o;
    } catch (ClassCastException e) {
        return null;
    }
}

public static void main(String[] args) {
    String k = convertInstanceOfObject(345435.34);
    System.out.println(k);
}

and the corresponding byte code is:

public static <T> T convertInstanceOfObject(java.lang.Object);
    Code:
       0: aload_0
       1: areturn
       2: astore_1
       3: aconst_null
       4: areturn
    Exception table:
       from    to  target type
           0     1     2   Class java/lang/ClassCastException

  public static void main(java.lang.String[]);
    Code:
       0: ldc2_w        #3                  // double 345435.34d
       3: invokestatic  #5                  // Method java/lang/Double.valueOf:(D)Ljava/lang/Double;
       6: invokestatic  #6                  // Method convertInstanceOfObject:(Ljava/lang/Object;)Ljava/lang/Object;
       9: checkcast     #7                  // class java/lang/String
      12: astore_1
      13: getstatic     #8                  // Field java/lang/System.out:Ljava/io/PrintStream;
      16: aload_1
      17: invokevirtual #9                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      20: return

Notice that checkcast byte code instruction happens in the main method not the convertInstanceOfObject and convertInstanceOfObject method does not have any instruction that can throw ClassCastException. Because the main method does not catch the ClassCastException hence when you execute the main method you will get a ClassCastException and not the expectation of printing null.

Now I modify the code to the accepted answer:

public static <T> T convertInstanceOfObject(Object o, Class<T> clazz) {
        try {
            return clazz.cast(o);
        } catch (ClassCastException e) {
            return null;
        }
    }
    public static void main(String[] args) {
        String k = convertInstanceOfObject(345435.34, String.class);
        System.out.println(k);
    }

The corresponding byte code is:

public static <T> T convertInstanceOfObject(java.lang.Object, java.lang.Class<T>);
    Code:
       0: aload_1
       1: aload_0
       2: invokevirtual #2                  // Method java/lang/Class.cast:(Ljava/lang/Object;)Ljava/lang/Object;
       5: areturn
       6: astore_2
       7: aconst_null
       8: areturn
    Exception table:
       from    to  target type
           0     5     6   Class java/lang/ClassCastException

  public static void main(java.lang.String[]);
    Code:
       0: ldc2_w        #4                  // double 345435.34d
       3: invokestatic  #6                  // Method java/lang/Double.valueOf:(D)Ljava/lang/Double;
       6: ldc           #7                  // class java/lang/String
       8: invokestatic  #8                  // Method convertInstanceOfObject:(Ljava/lang/Object;Ljava/lang/Class;)Ljava/lang/Object;
      11: checkcast     #7                  // class java/lang/String
      14: astore_1
      15: getstatic     #9                  // Field java/lang/System.out:Ljava/io/PrintStream;
      18: aload_1
      19: invokevirtual #10                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      22: return

Notice that there is an invokevirtual instruction in the convertInstanceOfObject method that calls Class.cast() method which throws ClassCastException which will be catch by the catch(ClassCastException e) bock and return null; hence, "null" is printed to console without any exception.

How to run TestNG from command line

If none of the above answers work, you can run the test in IDE, get the class path and use it in your command. Ex: If you are using Intellij IDEA, you can find it at the top of the console(screenshot below). Intellij Console

Clicking on the highlighted part expands and displays the complete class path.

you need to remove the references to jars inside the folder: JetBrains\IntelliJ IDEA Community Edition 2019.1.3

java -cp "path_copied" org.testng.TestNG testng.xml

DataTables fixed headers misaligned with columns in wide tables

I just figured out a way to fix the alignment issue. Changing the width of div containing the static header will fix its alignment. The optimal width I found is 98%. Please refer to the code.

The auto generated div:

<div class="dataTables_scrollHead" style="overflow: hidden; position: relative; border: 0px none; width: 100%;">

Width here is 100%, change it to 98% on initializing and reloading the data table.

jQuery('#dashboard').dataTable({
    "sEcho": "1",

    "aaSorting": [[aasortvalue, 'desc']],
    "bServerSide": true,
    "sAjaxSource": "NF.do?method=loadData&Table=dashboardReport",
    "bProcessing": true,
    "sPaginationType": "full_numbers",
    "sDom": "lrtip", // Add 'f' to add back in filtering
    "bJQueryUI": false,
    "sScrollX": "100%",
    "sScrollY": "450px",
    "iDisplayLength": '<%=recordCount%>',
    "bScrollCollapse": true,
    "bScrollAutoCss": true,
    "fnInitComplete": function () {
        jQuery('.dataTables_scrollHead').css('width', '98%'); //changing the width
    },
    "fnDrawCallback": function () {
        jQuery('.dataTables_scrollHead').css('width', '98%');//changing the width
    }
});

how to split the ng-repeat data with three columns using bootstrap

My approach was a mixture of things.

My objective was to have a grid adapting to the screen size. I wanted 3 columns for lg, 2 columns for sm and md, and 1 column for xs.

First, I created the following scope function, using angular $window service:

$scope.findColNumberPerRow = function() {
    var nCols;
    var width = $window.innerWidth;

    if (width < 768) {
        // xs
        nCols = 1;
    }
    else if(width >= 768 && width < 1200) {
         // sm and md
         nCols = 2
    } else if (width >= 1200) {
        // lg
        nCols = 3;
    }
    return nCols;
};

Then, I used the class proposed by @Cumulo Nimbus:

.new-row {
    clear: left;
}

In the div containing the ng-repeat, I added the resizable directive, as explained in this page, so that every time window is resized, angular $window service is updated with the new values.

Ultimately, in the repeated div I have:

ng-repeat="user in users" ng-class="{'new-row': ($index % findColNumberPerRow() === 0) }"

Please, let me know any flaws in this approach.

Hope it can be helpful.

Single vs Double quotes (' vs ")

I know LOTS of people wouldn't agree, but this is what I do and I really enjoy such a coding style: I actually don't use any quote in HTML unless it is absolutely necessary.

Example:

<form method=post action=#>
<fieldset>
<legend>Register here: </legend>
  <label for=account>Account: </label>
  <input id=account type=text name=account required><br>
  <label for=password>Password: </label>
  <input id=password type=password name=password required><br>
...

Double quotes are used only when there are spaces in the attribute values or whatever:

<form class="val1 val2 val3" method=post action=#>
  ...
</form>

Generating a PNG with matplotlib when DISPLAY is undefined

When signing into the server to execute the code use this instead:

ssh -X username@servername

the -X will get rid of the no display name and no $DISPLAY environment variable error

:)

How to determine the version of the C++ standard used by the compiler?

__cplusplus

In C++0x the macro __cplusplus will be set to a value that differs from (is greater than) the current 199711L.

C++0x FAQ by BS

Rounded Corners Image in Flutter

Use this Way in this circle image is also working + you have preloader also for network image:

new ClipRRect(
     borderRadius: new BorderRadius.circular(30.0),
     child: FadeInImage.assetNetwork(
          placeholder:'asset/loader.gif',
          image: 'Your Image Path',
      ),
    )

How do I put two increment statements in a C++ 'for' loop?

Try this

for(int i = 0; i != 5; ++i, ++j)
    do_something(i,j);

Sending HTTP POST Request In Java

Call HttpURLConnection.setRequestMethod("POST") and HttpURLConnection.setDoOutput(true); Actually only the latter is needed as POST then becomes the default method.

Get value from JToken that may not exist (best practices)

This is pretty much what the generic method Value() is for. You get exactly the behavior you want if you combine it with nullable value types and the ?? operator:

width = jToken.Value<double?>("width") ?? 100;

How can I format a decimal to always show 2 decimal places?

I suppose you're probably using the Decimal() objects from the decimal module? (If you need exactly two digits of precision beyond the decimal point with arbitrarily large numbers, you definitely should be, and that's what your question's title suggests...)

If so, the Decimal FAQ section of the docs has a question/answer pair which may be useful for you:

Q. In a fixed-point application with two decimal places, some inputs have many places and need to be rounded. Others are not supposed to have excess digits and need to be validated. What methods should be used?

A. The quantize() method rounds to a fixed number of decimal places. If the Inexact trap is set, it is also useful for validation:

>>> TWOPLACES = Decimal(10) ** -2       # same as Decimal('0.01')
>>> # Round to two places
>>> Decimal('3.214').quantize(TWOPLACES)
Decimal('3.21')
>>> # Validate that a number does not exceed two places
>>> Decimal('3.21').quantize(TWOPLACES, context=Context(traps=[Inexact]))
Decimal('3.21')
>>> Decimal('3.214').quantize(TWOPLACES, context=Context(traps=[Inexact]))
Traceback (most recent call last):
   ...
Inexact: None

The next question reads

Q. Once I have valid two place inputs, how do I maintain that invariant throughout an application?

If you need the answer to that (along with lots of other useful information), see the aforementioned section of the docs. Also, if you keep your Decimals with two digits of precision beyond the decimal point (meaning as much precision as is necessary to keep all digits to the left of the decimal point and two to the right of it and no more...), then converting them to strings with str will work fine:

str(Decimal('10'))
# -> '10'
str(Decimal('10.00'))
# -> '10.00'
str(Decimal('10.000'))
# -> '10.000'

Importing CSV with line breaks in Excel 2007

Short Answer

Remove the newline/linefeed characters (\n with Notepad++). Excel will still recognise the carriage return character (\r) to separate records.

Long Answer

As mentioned newline characters are supported inside CSV fields but Excel doesn't always handle them gracefully. I faced a similar issue with a third party CSV that possibly had encoding issues but didn't improve with encoding changes.

What worked for me was removing all newline characters (\n). This has the effect of collapsing fields to a single record assuming that your records are separated by the combination of a carriage return and a newline (CR/LF). Excel will then properly import the file and recognise new records by the carriage return.

Obviously a cleaner solution is to first replace the real newlines (\r\n) with a temporary character combination, replacing the newlines (\n) with your seperating character of choice (e.g. comma in a semicolon file) and then replacing the temporary characters with proper newlines again.

Hide keyboard in react-native

Here is my solution for Keyboard dismissing and scrolling to tapped TextInput (I am using ScrollView with keyboardDismissMode prop):

import React from 'react';
import {
  Platform,
  KeyboardAvoidingView,
  ScrollView
} from 'react-native';

const DismissKeyboard = ({ children }) => {
  const isAndroid = Platform.OS === 'android';
  const behavior = isAndroid ? false : 'padding';

  return (
    <KeyboardAvoidingView
      enabled
      behavior={ behavior }
      style={{ flex: 1}}
    >
      <ScrollView
        keyboardShouldPersistTaps={'always'}
        keyboardDismissMode={'on-drag'}
      >
        { children }
      </ScrollView>
    </KeyboardAvoidingView>
  );
};

export default DismissKeyboard;

usage:

render(){
   return(
     <DismissKeyboard>
       <TextInput
        style={{height: 40, borderColor: 'gray', borderWidth: 1}}
        onChangeText={(text) => this.setState({text})}
        value={this.state.text}
      />
     </DismissKeyboard>
   );
}

Pattern matching using a wildcard

You can also use package data.table and it's Like function, details given below How to select R data.table rows based on substring match (a la SQL like)

Create a string with n characters

For good performance, combine answers from aznilamir and from FrustratedWithFormsDesigner

private static final String BLANKS = "                       ";
private static String getBlankLine( int length )
{
    if( length <= BLANKS.length() )
    {
        return BLANKS.substring( 0, length );
    }
    else
    {
        char[] array = new char[ length ];
        Arrays.fill( array, ' ' );
        return new String( array );
    }
}

Adjust size of BLANKS depending on your requirements. My specific BLANKS string is about 200 characters length.

How do I script a "yes" response for installing programs?

You might not have the ability to install Expect on the target server. This is often the case when one writes, say, a Jenkins job.

If so, I would consider something like the answer to the following on askubuntu.com:

https://askubuntu.com/questions/338857/automatically-enter-input-in-command-line

printf 'y\nyes\nno\nmaybe\n' | ./script_that_needs_user_input

Note that in some rare cases the command does not require the user to press enter after the character. in that case leave the newlines out:

printf 'yyy' | ./script_that_needs_user_input

For sake of completeness you can also use a here document:

./script_that_needs_user_input << EOF
y
y
y
EOF

Or if your shell supports it a here string:

./script <<< "y
y
y
"

Or you can create a file with one input per line:

./script < inputfile

Again, all credit for this answer goes to the author of the answer on askubuntu.com, lesmana.

How to work with string fields in a C struct?

I think this solution uses less code and is easy to understand even for newbie.

For string field in struct, you can use pointer and reassigning the string to that pointer will be straightforward and simpler.

Define definition of struct:

typedef struct {
  int number;
  char *name;
  char *address;
  char *birthdate;
  char gender;
} Patient;

Initialize variable with type of that struct:

Patient patient;
patient.number = 12345;
patient.address = "123/123 some road Rd.";
patient.birthdate = "2020/12/12";
patient.gender = "M";

It is that simple. Hope this answer helps many developers.

Eliminate space before \begin{itemize}

Try \vspace{-5mm} before the itemize.

Load More Posts Ajax Button in WordPress

If I'm not using any category then how can I use this code? Actually, I want to use this code for custom post type.

SSL Error When installing rubygems, Unable to pull data from 'https://rubygems.org/

Latest findings...

https://gist.github.com/luislavena/f064211759ee0f806c88

Most importantly...download https://raw.githubusercontent.com/rubygems/rubygems/master/lib/rubygems/ssl_certs/rubygems.org/AddTrustExternalCARoot-2048.pem

Figure out where to stick it

C:\>gem which rubygems
C:/Ruby21/lib/ruby/2.1.0/rubygems.rb

Then just copy the .pem file in ../2.1.0/rubygems/ssl_certs/ and go on about your business.

Way to run Excel macros from command line or batch file?

Instead of directly comparing the strings (VB won't find them equal since GetEnvironmentVariable returns a string of length 255) write this:

Private Sub Workbook_Open()     
    If InStr(1, GetEnvironmentVariable("InBatch"), "TRUE", vbTextCompare) Then
        Debug.Print "Batch"  
        Call Macro
    Else    
        Debug.Print "Normal"     
    End If 

End Sub 

concatenate two strings

You need to use the string concatenation operator +

String both = name + "-" + dest;

Regex to match only letters

You can try this regular expression : [^\W\d_] or [a-zA-Z].

Why do I need to do `--set-upstream` all the time?

You can also do git push -u origin $(current_branch)

What is the size of a boolean variable in Java?

The actual information represented by a boolean value in Java is one bit: 1 for true, 0 for false. However, the actual size of a boolean variable in memory is not precisely defined by the Java specification. See Primitive Data Types in Java.

The boolean data type has only two possible values: true and false. Use this data type for simple flags that track true/false conditions. This data type represents one bit of information, but its "size" isn't something that's precisely defined.

how to execute a scp command with the user name and password in one line

Thanks for your feed back got it to work I used the sshpass tool.

sshpass -p 'password' scp [email protected]:sys_config /var/www/dev/

How do I remove lines between ListViews on Android?

If this android:divider="@null" doesn't work, maybe changing your ListViews for Recycler Views? 

CSS3 Box Shadow on Top, Left, and Right Only

The following code did it for me to make a shadow inset of the right side:

-moz-box-shadow: inset -10px 0px 10px -10px #000;
-webkit-box-shadow: inset -10px 0px 10px -10px #000;
box-shadow: inset -10px 0px 10px -10px #000;

Hope it will help!!!!

Format date and time in a Windows batch script

:: =============================================================
:: Batch file to display Date and Time seprated by undescore.
:: =============================================================
:: Read the system date.
:: =============================================================
@SET MyDate=%DATE%
@SET MyDate=%MyDate:/=:%
@SET MyDate=%MyDate:-=:%
@SET MyDate=%MyDate: =:%
@SET MyDate=%MyDate:\=:%
@SET MyDate=%MyDate::=_%
:: =============================================================
:: Read the system time.
:: =============================================================
@SET MyTime=%TIME%
@SET MyTime=%MyTime: =0%
@SET MyTime=%MyTime:.=:%
@SET MyTime=%MyTime::=_%
:: =============================================================
:: Build the DateTime string.
:: =============================================================
@SET DateTime=%MyDate%_%MyTime%
:: =============================================================
:: Display the Date and Time as it is now.
:: =============================================================
@ECHO MyDate="%MyDate%" MyTime="%MyTime%" DateTime="%DateTime%"
:: =============================================================
:: Wait before close.
:: =============================================================
@PAUSE
:: =============================================================

How and when to use SLEEP() correctly in MySQL?

SELECT ...
SELECT SLEEP(5);
SELECT ...

But what are you using this for? Are you trying to circumvent/reinvent mutexes or transactions?

How do I measure request and response times at once using cURL?

Another way is configuring ~/.curlrc like this

-w "\n\n==== cURL measurements stats ====\ntotal: %{time_total} seconds \nsize: %{size_download} bytes \ndnslookup: %{time_namelookup} seconds \nconnect: %{time_connect} seconds \nappconnect: %{time_appconnect} seconds \nredirect: %{time_redirect} seconds \npretransfer: %{time_pretransfer} seconds \nstarttransfer: %{time_starttransfer} seconds \ndownloadspeed: %{speed_download} byte/sec \nuploadspeed: %{speed_upload} byte/sec \n\n"

So the output of curl is

?? curl -I https://google.com
HTTP/2 301
location: https://www.google.com/
content-type: text/html; charset=UTF-8
date: Mon, 04 Mar 2019 08:02:43 GMT
expires: Wed, 03 Apr 2019 08:02:43 GMT
cache-control: public, max-age=2592000
server: gws
content-length: 220
x-xss-protection: 1; mode=block
x-frame-options: SAMEORIGIN
alt-svc: quic=":443"; ma=2592000; v="44,43,39"



==== cURL measurements stats ====
total: 0.211117 seconds
size: 0 bytes
dnslookup: 0.067179 seconds
connect: 0.098817 seconds
appconnect: 0.176232 seconds
redirect: 0.000000 seconds
pretransfer: 0.176438 seconds
starttransfer: 0.209634 seconds
downloadspeed: 0.000 byte/sec
uploadspeed: 0.000 byte/sec

How does bitshifting work in Java?

Firstly, you can not shift a byte in java, you can only shift an int or a long. So the byte will undergo promotion first, e.g.

00101011 -> 00000000000000000000000000101011

or

11010100 -> 11111111111111111111111111010100

Now, x >> N means (if you view it as a string of binary digits):

  • The rightmost N bits are discarded
  • The leftmost bit is replicated as many times as necessary to pad the result to the original size (32 or 64 bits), e.g.

00000000000000000000000000101011 >> 2 -> 00000000000000000000000000001010

11111111111111111111111111010100 >> 2 -> 11111111111111111111111111110101

Percentage Height HTML 5/CSS

I am trying to set a div to a certain percentage height in CSS

Percentage of what?

To set a percentage height, its parent element(*) must have an explicit height. This is fairly self-evident, in that if you leave height as auto, the block will take the height of its content... but if the content itself has a height expressed in terms of percentage of the parent you've made yourself a little Catch 22. The browser gives up and just uses the content height.

So the parent of the div must have an explicit height property. Whilst that height can also be a percentage if you want, that just moves the problem up to the next level.

If you want to make the div height a percentage of the viewport height, every ancestor of the div, including <html> and <body>, have to have height: 100%, so there is a chain of explicit percentage heights down to the div.

(*: or, if the div is positioned, the ‘containing block’, which is the nearest ancestor to also be positioned.)

Alternatively, all modern browsers and IE>=9 support new CSS units relative to viewport height (vh) and viewport width (vw):

div {
    height:100vh; 
}

See here for more info.

Git commit date

You can use the git show command.

To get the last commit date from git repository in a long(Unix epoch timestamp):

  • Command: git show -s --format=%ct
  • Result: 1605103148

Note: You can visit the git-show documentation to get a more detailed description of the options.

Pretty git branch graphs

For more detailed textual output, please try:

git log --graph --date-order -C -M --pretty=format:"<%h> %ad [%an] %Cgreen%d%Creset %s" --all --date=short

You can write alias in $HOME/.gitconfig

[alias]
    graph = log --graph --date-order -C -M --pretty=format:\"<%h> %ad [%an] %Cgreen%d%Creset %s\" --all --date=short

Chrome violation : [Violation] Handler took 83ms of runtime

It seems you have found your solution, but still it will be helpful to others, on this page on point based on Chrome 59.

4.Note the red triangle in the top-right of the Animation Frame Fired event. Whenever you see a red triangle, it's a warning that there may be an issue related to this event.

If you hover on these triangle you can see those are the violation handler errors and as per point 4. yes there is some issue related to that event.

RESTful Authentication

I think restful authentication involves the passing of an authentication token as a parameter in the request. Examples are the use of apikeys by api's. I don't believe the use of cookies or http auth qualifies.

What's the difference between struct and class in .NET?

Well, for starters, a struct is passed by value rather than by reference. Structs are good for relatively simple data structures, while classes have a lot more flexibility from an architectural point of view via polymorphism and inheritance.

Others can probably give you more detail than I, but I use structs when the structure that I am going for is simple.

Create a button with rounded border

FlatButton(
          onPressed: null,
          child: Text('Button', style: TextStyle(
              color: Colors.blue
            )
          ),
          textColor: MyColor.white,
          shape: RoundedRectangleBorder(side: BorderSide(
            color: Colors.blue,
            width: 1,
            style: BorderStyle.solid
          ), borderRadius: BorderRadius.circular(50)),
        )

Problems with jQuery getJSON using local files in Chrome

@Mike On Mac, type this in Terminal:

open -b com.google.chrome --args --disable-web-security

How to set div width using ng-style

The syntax of ng-style is not quite that. It accepts a dictionary of keys (attribute names) and values (the value they should take, an empty string unsets them) rather than only a string. I think what you want is this:

<div ng-style="{ 'width' : width, 'background' : bgColor }"></div>

And then in your controller:

$scope.width = '900px';
$scope.bgColor = 'red';

This preserves the separation of template and the controller: the controller holds the semantic values while the template maps them to the correct attribute name.

How can I capitalize the first letter of each word in a string using JavaScript?

I think this way should be faster; cause it doesn't split string and join it again; just using regex.

var str = text.replace(/(^\w{1})|(\s{1}\w{1})/g, match => match.toUpperCase());

Explanation:

  1. (^\w{1}): match first char of string
  2. |: or
  3. (\s{1}\w{1}): match one char that came after one space
  4. g: match all
  5. match => match.toUpperCase(): replace with can take function, so; replace match with upper case match

Relative imports for the billionth time

Another dirty but working workaround. Assumes you are on top level of your package.

import sys
from os.path import dirname, basename

if __package__ is None:
    sys.path.append('..')
    __package__ = basename(dirname(sys.argv[0]))

from . import your_module

The advantage vs another answer here is that you don't need to change imports which are autogenerated by IDE.

Read and write to binary files in C?

This is an example to read and write binary jjpg or wmv video file. FILE *fout; FILE *fin;

Int ch;
char *s;
fin=fopen("D:\\pic.jpg","rb");
if(fin==NULL)
     {  printf("\n Unable to open the file ");
         exit(1);
      }

 fout=fopen("D:\\ newpic.jpg","wb");
 ch=fgetc(fin);
       while (ch!=EOF)
             { 
                  s=(char *)ch;
                  printf("%c",s);
                 ch=fgetc (fin):
                 fputc(s,fout);
                 s++;
              }

        printf("data read and copied");
        fclose(fin);
        fclose(fout);

Unresolved Import Issues with PyDev and Eclipse

Here is what worked for me (sugested by soulBit):

1) Restart using restart from the file menu
2) Once it started again, manually close and open it.

This is the simplest solution ever and it completely removes the annoying thing.

how to show calendar on text box click in html

jQuery Mobile has a datepicker too. Source

Just include the following files,

  <script src="jQuery.ui.datepicker.js"></script>
  <script src="jquery.ui.datepicker.mobile.js"></script>

Opening XML page shows "This XML file does not appear to have any style information associated with it."

This XML file does not appear to have any style information associated with it. The document tree is shown below.

You will get this error in the client side when the client (the webbrowser) for some reason interprets the HTTP response content as text/xml instead of text/html and the parsed XML tree doesn't have any XML-stylesheet. In other words, the webbrowser incorrectly parsed the retrieved HTTP response content as XML instead of as HTML due to the wrong or missing HTTP response content type.

In case of JSF/Facelets files which have the default extension of .xhtml, that can in turn happen if the HTTP request hasn't invoked the FacesServlet and thus it wasn't able to parse the Facelets file and generate the desired HTML output based on the XHTML source code. Firefox is then merely guessing the HTTP response content type based on the .xhtml file extension which is in your Firefox configuration apparently by default interpreted as text/xml.

You need to make sure that the HTTP request URL, as you see in browser's address bar, matches the <url-pattern> of the FacesServlet as registered in webapp's web.xml, so that it will be invoked and be able to generate the desired HTML output based on the XHTML source code. If it's for example *.jsf, then you need to open the page by /some.jsf instead of /some.xhtml. Alternatively, you can also just change the <url-pattern> to *.xhtml. This way you never need to fiddle with virtual URLs.

See also:


Note thus that you don't actually need a XML stylesheet. This all was just misinterpretation by the webbrowser while trying to do its best to make something presentable out of the retrieved HTTP response content. It should actually have retrieved the properly generated HTML output, Firefox surely knows precisely how to deal with HTML content.

What is "loose coupling?" Please provide examples

Tightly coupled code relies on a concrete implementation. If I need a list of strings in my code and I declare it like this (in Java)

ArrayList<String> myList = new ArrayList<String>();

then I'm dependent on the ArrayList implementation.

If I want to change that to loosely coupled code, I make my reference an interface (or other abstract) type.

List<String> myList = new ArrayList<String>();

This prevents me from calling any method on myList that's specific to the ArrayList implementation. I'm limited to only those methods defined in the List interface. If I decide later that I really need a LinkedList, I only need to change my code in one place, where I created the new List, and not in 100 places where I made calls to ArrayList methods.

Of course, you can instantiate an ArrayList using the first declaration and restrain yourself from not using any methods that aren't part of the List interface, but using the second declaration makes the compiler keep you honest.

Android Studio - No JVM Installation found

Control Panel -> System -> Advanced system settings -> Environment Variables

I changed JAVA_HOME to JAVA and again changed JAVA to JAVA_HOME.

and Its working fine.

Why is "1000000000000000 in range(1000000000000001)" so fast in Python 3?

Use the source, Luke!

In CPython, range(...).__contains__ (a method wrapper) will eventually delegate to a simple calculation which checks if the value can possibly be in the range. The reason for the speed here is we're using mathematical reasoning about the bounds, rather than a direct iteration of the range object. To explain the logic used:

  1. Check that the number is between start and stop, and
  2. Check that the stride value doesn't "step over" our number.

For example, 994 is in range(4, 1000, 2) because:

  1. 4 <= 994 < 1000, and
  2. (994 - 4) % 2 == 0.

The full C code is included below, which is a bit more verbose because of memory management and reference counting details, but the basic idea is there:

static int
range_contains_long(rangeobject *r, PyObject *ob)
{
    int cmp1, cmp2, cmp3;
    PyObject *tmp1 = NULL;
    PyObject *tmp2 = NULL;
    PyObject *zero = NULL;
    int result = -1;

    zero = PyLong_FromLong(0);
    if (zero == NULL) /* MemoryError in int(0) */
        goto end;

    /* Check if the value can possibly be in the range. */

    cmp1 = PyObject_RichCompareBool(r->step, zero, Py_GT);
    if (cmp1 == -1)
        goto end;
    if (cmp1 == 1) { /* positive steps: start <= ob < stop */
        cmp2 = PyObject_RichCompareBool(r->start, ob, Py_LE);
        cmp3 = PyObject_RichCompareBool(ob, r->stop, Py_LT);
    }
    else { /* negative steps: stop < ob <= start */
        cmp2 = PyObject_RichCompareBool(ob, r->start, Py_LE);
        cmp3 = PyObject_RichCompareBool(r->stop, ob, Py_LT);
    }

    if (cmp2 == -1 || cmp3 == -1) /* TypeError */
        goto end;
    if (cmp2 == 0 || cmp3 == 0) { /* ob outside of range */
        result = 0;
        goto end;
    }

    /* Check that the stride does not invalidate ob's membership. */
    tmp1 = PyNumber_Subtract(ob, r->start);
    if (tmp1 == NULL)
        goto end;
    tmp2 = PyNumber_Remainder(tmp1, r->step);
    if (tmp2 == NULL)
        goto end;
    /* result = ((int(ob) - start) % step) == 0 */
    result = PyObject_RichCompareBool(tmp2, zero, Py_EQ);
  end:
    Py_XDECREF(tmp1);
    Py_XDECREF(tmp2);
    Py_XDECREF(zero);
    return result;
}

static int
range_contains(rangeobject *r, PyObject *ob)
{
    if (PyLong_CheckExact(ob) || PyBool_Check(ob))
        return range_contains_long(r, ob);

    return (int)_PySequence_IterSearch((PyObject*)r, ob,
                                       PY_ITERSEARCH_CONTAINS);
}

The "meat" of the idea is mentioned in the line:

/* result = ((int(ob) - start) % step) == 0 */ 

As a final note - look at the range_contains function at the bottom of the code snippet. If the exact type check fails then we don't use the clever algorithm described, instead falling back to a dumb iteration search of the range using _PySequence_IterSearch! You can check this behaviour in the interpreter (I'm using v3.5.0 here):

>>> x, r = 1000000000000000, range(1000000000000001)
>>> class MyInt(int):
...     pass
... 
>>> x_ = MyInt(x)
>>> x in r  # calculates immediately :) 
True
>>> x_ in r  # iterates for ages.. :( 
^\Quit (core dumped)

lvalue required as left operand of assignment error when using C++

When you have an assignment operator in a statement, the LHS of the operator must be something the language calls an lvalue. If the LHS of the operator does not evaluate to an lvalue, the value from the RHS cannot be assigned to the LHS.

You cannot use:

10 = 20;

since 10 does not evaluate to an lvalue.

You can use:

int i;
i = 20;

since i does evaluate to an lvalue.

You cannot use:

int i;
i + 1 = 20;

since i + 1 does not evaluate to an lvalue.

In your case, p + 1 does not evaluate to an lavalue. Hence, you cannot use

p + 1 = p;

href="tel:" and mobile numbers

I know the OP is asking about international country codes but for North America, you could use the following:

_x000D_
_x000D_
<a href="tel:+1-847-555-5555">1-847-555-5555</a>

<a href="tel:+18475555555">Click Here To Call Support 1-847-555-5555</a>
_x000D_
_x000D_
_x000D_

This might help you.

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

Add "android-support-v7-appcompat.jar" to Android Private Libraries

How to Parse a JSON Object In Android

JSONArray jsonArray = new JSONArray(yourJsonString);

for (int i = 0; i < jsonArray.length(); i++) {
     JSONObject obj1 = jsonArray.getJSONObject(i);
     JSONArray results = patient.getJSONArray("results");
     String indexForPhone =  patientProfile.getJSONObject(0).getString("indexForPhone"));
}

Change to JSONArray, then convert to JSONObject.

Warning: Use the 'defaultValue' or 'value' props on <select> instead of setting 'selected' on <option>

With Hooks and useState

Use defaultValue to select the default value.

    const statusOptions = [
        { value: 1, label: 'Publish' },
        { value: 0, label: 'Unpublish' }
    ];
    const [statusValue, setStatusValue] = useState('');
    const handleStatusChange = e => {
        setStatusValue(e.value);
    }

return(
<>
<Select options={statusOptions} 
    defaultValue={[{ value: published, label: published == 1 ? 'Publish' : 'Unpublish' }]} 
    onChange={handleStatusChange} 
    value={statusOptions.find(obj => obj.value === statusValue)} required />
</>
)

Why does my favicon not show up?

Try this:

<link href="img/favicon.ico" rel="shortcut icon" type="image/x-icon" />

Read a HTML file into a string variable in memory

Use File.ReadAllText passing file location as an argument.

However, if your real goal is to parse html then I would recommend using Html Agility Pack.

Android Fatal signal 11 (SIGSEGV) at 0x636f7d89 (code=1). How can it be tracked down?

I also got this error many times and I solved it. This error will be faced in case of memory management in native side.

Your application is accessing memory outside of its address space. This is most likely an invalid pointer access. SIGSEGV = segmentation fault in native code. Since it is not occurring in Java code you won't see a stack trace with details. However, you may still see some stack trace information in the logcat if you look around a bit after the application process crashes. It will not tell you the line number within the file, but will tell you which object files and addresses were in use in the call chain. From there you can often figure out which area of the code is problematic. You can also setup a gdb native connection to the target process and catch it in the debugger.

How to add hours to current time in python

Import datetime and timedelta:

>>> from datetime import datetime, timedelta
>>> str(datetime.now() + timedelta(hours=9))[11:19]
'01:41:44'

But the better way is:

>>> (datetime.now() + timedelta(hours=9)).strftime('%H:%M:%S')
'01:42:05'

You can refer strptime and strftime behavior to better understand how python processes dates and time field

Adding Buttons To Google Sheets and Set value to Cells on clicking

You can insert an image that looks like a button. Then attach a script to the image.

  • INSERT menu
  • Image

Insert Image

You can insert any image. The image can be edited in the spreadsheet

Edit Image

Image of a Button

Image of Button

Assign a function name to an image:

Assign Function

Invoke-WebRequest, POST with parameters

This just works:

$body = @{
 "UserSessionId"="12345678"
 "OptionalEmail"="[email protected]"
} | ConvertTo-Json

$header = @{
 "Accept"="application/json"
 "connectapitoken"="97fe6ab5b1a640909551e36a071ce9ed"
 "Content-Type"="application/json"
} 

Invoke-RestMethod -Uri "http://MyServer/WSVistaWebClient/RESTService.svc/member/search" -Method 'Post' -Body $body -Headers $header | ConvertTo-HTML

Refresh certain row of UITableView based on Int in Swift

SWIFT 4.2

    func reloadYourRows(name: <anyname>) {
    let row = <your array name>.index(of: <name passing in>)
    let reloadPath = IndexPath(row: row!, section: 0)
    tableView.reloadRows(at: [reloadPath], with: .middle)
    }

Changing default encoding of Python?

If you get this error when you try to pipe/redirect output of your script

UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-5: ordinal not in range(128)

Just export PYTHONIOENCODING in console and then run your code.

export PYTHONIOENCODING=utf8

Why SpringMVC Request method 'GET' not supported?

I also had the same issue. I changed it to the following and it worked.

Java :

@RequestMapping(value = "/test", method = RequestMethod.GET)

HTML code:

  <form action="<%=request.getContextPath() %>/test" method="GET">
    <input type="submit" value="submit"> 
    </form>

By default if you do not specify http method in a form it uses GET. To use POST method you need specifically state it.

Hope this helps.

How to change the map center in Leaflet.js

Use map.panTo(); does not do anything if the point is in the current view. Use map.setView() instead.

I had a polyline and I had to center map to a new point in polyline at every second. Check the code : GOOD: https://jsfiddle.net/nstudor/xcmdwfjk/

mymap.setView(point, 11, { animation: true });        

BAD: https://jsfiddle.net/nstudor/Lgahv905/

mymap.panTo(point);
mymap.setZoom(11);