Programs & Examples On #Twitter button

Easy way to test a URL for 404 in PHP?

If your running php5 you can use:

$url = 'http://www.example.com';
print_r(get_headers($url, 1));

Alternatively with php4 a user has contributed the following:

/**
This is a modified version of code from "stuart at sixletterwords dot com", at 14-Sep-2005 04:52. This version tries to emulate get_headers() function at PHP4. I think it works fairly well, and is simple. It is not the best emulation available, but it works.

Features:
- supports (and requires) full URLs.
- supports changing of default port in URL.
- stops downloading from socket as soon as end-of-headers is detected.

Limitations:
- only gets the root URL (see line with "GET / HTTP/1.1").
- don't support HTTPS (nor the default HTTPS port).
*/

if(!function_exists('get_headers'))
{
    function get_headers($url,$format=0)
    {
        $url=parse_url($url);
        $end = "\r\n\r\n";
        $fp = fsockopen($url['host'], (empty($url['port'])?80:$url['port']), $errno, $errstr, 30);
        if ($fp)
        {
            $out  = "GET / HTTP/1.1\r\n";
            $out .= "Host: ".$url['host']."\r\n";
            $out .= "Connection: Close\r\n\r\n";
            $var  = '';
            fwrite($fp, $out);
            while (!feof($fp))
            {
                $var.=fgets($fp, 1280);
                if(strpos($var,$end))
                    break;
            }
            fclose($fp);

            $var=preg_replace("/\r\n\r\n.*\$/",'',$var);
            $var=explode("\r\n",$var);
            if($format)
            {
                foreach($var as $i)
                {
                    if(preg_match('/^([a-zA-Z -]+): +(.*)$/',$i,$parts))
                        $v[$parts[1]]=$parts[2];
                }
                return $v;
            }
            else
                return $var;
        }
    }
}

Both would have a result similar to:

Array
(
    [0] => HTTP/1.1 200 OK
    [Date] => Sat, 29 May 2004 12:28:14 GMT
    [Server] => Apache/1.3.27 (Unix)  (Red-Hat/Linux)
    [Last-Modified] => Wed, 08 Jan 2003 23:11:55 GMT
    [ETag] => "3f80f-1b6-3e1cb03b"
    [Accept-Ranges] => bytes
    [Content-Length] => 438
    [Connection] => close
    [Content-Type] => text/html
)

Therefore you could just check to see that the header response was OK eg:

$headers = get_headers($url, 1);
if ($headers[0] == 'HTTP/1.1 200 OK') {
//valid 
}

if ($headers[0] == 'HTTP/1.1 301 Moved Permanently') {
//moved or redirect page
}

W3C Codes and Definitions

Replace Default Null Values Returned From Left Outer Join

That's as easy as

IsNull(FieldName, 0)

Or more completely:

SELECT iar.Description, 
  ISNULL(iai.Quantity,0) as Quantity, 
  ISNULL(iai.Quantity * rpl.RegularPrice,0) as 'Retail', 
  iar.Compliance 
FROM InventoryAdjustmentReason iar
LEFT OUTER JOIN InventoryAdjustmentItem iai  on (iar.Id = iai.InventoryAdjustmentReasonId)
LEFT OUTER JOIN Item i on (i.Id = iai.ItemId)
LEFT OUTER JOIN ReportPriceLookup rpl on (rpl.SkuNumber = i.SkuNo)
WHERE iar.StoreUse = 'yes'

Clearing <input type='file' /> using jQuery

Jquery is supposed to take care of the cross-browser/older browser issues for you.

This works on modern browsers that I tested: Chromium v25, Firefox v20, Opera v12.14

Using jquery 1.9.1

HTML

<input id="fileopen" type="file" value="" />
<button id="clear">Clear</button>

Jquery

$("#clear").click(function () {
    $("#fileopen").val("");
});

On jsfiddle

The following javascript solution also worked for me on the browsers mention above.

document.getElementById("clear").addEventListener("click", function () {
    document.getElementById("fileopen").value = "";
}, false);

On jsfiddle

I have no way to test with IE, but theoretically this should work. If IE is different enough that the Javascript version does not work because MS have done it in a different way, the jquery method should in my opinion deal with it for you, else it would be worth pointing it out to the jquery team along with the method that IE requires. (I see people saying "this won't work on IE", but no vanilla javascript to show how it does work on IE (supposedly a "security feature"?), perhaps report it as a bug to MS too (if they would count it as such), so that it gets fixed in any newer release)

Like mentioned in another answer, a post on the jquery forum

 if ($.browser.msie) {
      $('#file').replaceWith($('#file').clone());
 } else {
      $('#file').val('');
 }

But jquery have now removed support for browser testing, jquery.browser.

This javascript solution also worked for me, it is the vanilla equivalent of the jquery.replaceWith method.

document.getElementById("clear").addEventListener("click", function () {
    var fileopen = document.getElementById("fileopen"),
        clone = fileopen.cloneNode(true);

    fileopen.parentNode.replaceChild(clone, fileopen);
}, false);

On jsfiddle

The important thing to note is that the cloneNode method does not preserve associated event handlers.

See this example.

document.getElementById("fileopen").addEventListener("change", function () {
    alert("change");
}, false);

document.getElementById("clear").addEventListener("click", function () {
    var fileopen = document.getElementById("fileopen"),
        clone = fileopen.cloneNode(true);

    fileopen.parentNode.replaceChild(clone, fileopen);
}, false);

On jsfiddle

But jquery.clone offers this [*1]

$("#fileopen").change(function () {
    alert("change");
});

$("#clear").click(function () {
    var fileopen = $("#fileopen"),
        clone = fileopen.clone(true);

    fileopen.replaceWith(clone);
});

On jsfiddle

[*1] jquery is able to do this if the events were added by jquery's methods as it keeps a copy in jquery.data, it does not work otherwise, so it's a bit of a cheat/work-around and means things are not compatible between different methods or libraries.

document.getElementById("fileopen").addEventListener("change", function () {
    alert("change");
}, false);

$("#clear").click(function () {
    var fileopen = $("#fileopen"),
        clone = fileopen.clone(true);

    fileopen.replaceWith(clone);
});

On jsfiddle

You can not get the attached event handler direct from the element itself.

Here is the general principle in vanilla javascript, this is how jquery an all other libraries do it (roughly).

(function () {
    var listeners = [];

    function getListeners(node) {
        var length = listeners.length,
            i = 0,
            result = [],
            listener;

        while (i < length) {
            listener = listeners[i];
            if (listener.node === node) {
                result.push(listener);
            }

            i += 1;
        }

        return result;
    }

    function addEventListener(node, type, handler) {
        listeners.push({
            "node": node,
                "type": type,
                "handler": handler
        });

        node.addEventListener(type, handler, false);
    }

    function cloneNode(node, deep, withEvents) {
        var clone = node.cloneNode(deep),
            attached,
            length,
            evt,
            i = 0;

        if (withEvents) {
            attached = getListeners(node);
            if (attached) {
                length = attached.length;
                while (i < length) {
                    evt = attached[i];
                    addEventListener(clone, evt.type, evt.handler);

                    i += 1;
                }
            }
        }

        return clone;
    }

    addEventListener(document.getElementById("fileopen"), "change", function () {
        alert("change");
    });

    addEventListener(document.getElementById("clear"), "click", function () {
        var fileopen = document.getElementById("fileopen"),
            clone = cloneNode(fileopen, true, true);

        fileopen.parentNode.replaceChild(clone, fileopen);
    });
}());

On jsfiddle

Of course jquery and other libraries have all the other support methods required for maintaining such a list, this is just a demonstration.

Oracle SQL - DATE greater than statement

you have to use the To_Date() function to convert the string to date ! http://www.techonthenet.com/oracle/functions/to_date.php

How to create our own Listener interface in android?

I have created a Generic AsyncTask Listener which get result from AsycTask seperate class and give it to CallingActivity using Interface Callback.

new GenericAsyncTask(context,new AsyncTaskCompleteListener()
        {
             public void onTaskComplete(String response) 
             {
                 // do your work. 
             }
        }).execute();

Interface

interface AsyncTaskCompleteListener<T> {
   public void onTaskComplete(T result);
}

GenericAsyncTask

class GenericAsyncTask extends AsyncTask<String, Void, String> 
{
    private AsyncTaskCompleteListener<String> callback;

    public A(Context context, AsyncTaskCompleteListener<String> cb) {
        this.context = context;
        this.callback = cb;
    }

    protected void onPostExecute(String result) {
       finalResult = result;
       callback.onTaskComplete(result);
   }  
}

Have a look at this , this question for more details.

GIT clone repo across local file system in windows

the answer with the host name didn't work for me but this did :

git clone file:////home/git/repositories/MyProject.git/

Where is svn.exe in my machine?

During the installation of TortoiseSVN, check the Command Line Client Tools. This will create the file svn.exe inside the folder C:\Program Files\TortoiseSVN\bin.

Pylint "unresolved import" error in Visual Studio Code

Alternative way: use the command interface!

Cmd/Ctrl + Shift + P ? Python: Select Interpreter ? choose the one with the packages you look for:

Enter image description here

Replace X-axis with own values

Not sure if it's what you mean, but you can do this:

plot(1:10, xaxt = "n", xlab='Some Letters')
axis(1, at=1:10, labels=letters[1:10])

which then gives you the graph:

enter image description here

What certificates are trusted in truststore?

Is there any equivalent for the truststore? How can I view the trusted certificates?

Yes there is.The exact same command since keystore and truststore differ only in what they store i.e. private key or signed public key (certificate)

No other difference

Resetting a form in Angular 2 after submit

For Angular 2 Final, we now have a new API that cleanly resets the form:

@Component({...})
class App {

    form: FormGroup;
     ...
    reset() {
       this.form.reset();
   }
}

This API not only resets the form values, but also sets the form field states back to ng-pristine and ng-untouched.

Invoke a second script with arguments from a script

We can use splatting for this:

& $command @args

where @args (automatic variable $args) is splatted into array of parameters.

Under PS, 5.1

Insert PHP code In WordPress Page and Post

WordPress does not execute PHP in post/page content by default unless it has a shortcode.

The quickest and easiest way to do this is to use a plugin that allows you to run PHP embedded in post content.

There are two other "quick and easy" ways to accomplish it without a plugin:

  • Make it a shortcode (put it in functions.php and have it echo the country name) which is very easy - see here: Shortcode API at WP Codex

  • Put it in a template file - make a custom template for that page based on your default page template and add the PHP into the template file rather than the post content: Custom Page Templates

How can we generate getters and setters in Visual Studio?

You can also use "propfull" and hit TAB twice.

The variable and property with get and set will be generated.

Check that a variable is a number in UNIX shell

Taking the value from Command line and showing THE INPUT IS DECIMAL/NON-DECIMAL and NUMBER or not:

NUMBER=$1

            IsDecimal=`echo "$NUMBER" | grep "\."`

if [ -n "$IsDecimal" ]
then
            echo "$NUMBER is Decimal"
            var1=`echo "$NUMBER" | cut -d"." -f1`
            var2=`echo "$NUMBER" | cut -d"." -f2`

            Digit1=`echo "$var1" | egrep '^-[0-9]+$'`
            Digit2=`echo "$var1" | egrep '^[0-9]+$'`
            Digit3=`echo "$var2" | egrep '^[0-9]+$'`


            if [ -n "$Digit1" ] && [ -n "$Digit3" ]
            then
                echo "$NUMBER is a number"
            elif [ -n "$Digit2" ] && [ -n "$Digit3" ]
            then
                echo "$NUMBER is a number"

            else
                echo "$NUMBER is not a number"
            fi
else
            echo "$NUMBER is not Decimal"

            Digit1=`echo "$NUMBER" | egrep '^-[0-9]+$'`
            Digit2=`echo "$NUMBER" | egrep '^[0-9]+$'`

            if [ -n "$Digit1" ] || [ -n "$Digit2" ]; then
                echo "$NUMBER is a number"
            else
                echo "$NUMBER is not a number"
            fi
fi

How to use *ngIf else?

For Angular 9/8

Source Link with Examples

    export class AppComponent {
      isDone = true;
    }

1) *ngIf

    <div *ngIf="isDone">
      It's Done!
    </div>

    <!-- Negation operator-->
    <div *ngIf="!isDone">
      It's Not Done!
    </div>

2) *ngIf and Else

    <ng-container *ngIf="isDone; else elseNotDone">
      It's Done!
    </ng-container>

    <ng-template #elseNotDone>
      It's Not Done!
    </ng-template>

3) *ngIf, Then and Else

    <ng-container *ngIf="isDone;  then iAmDone; else iAmNotDone">
    </ng-container>

    <ng-template #iAmDone>
      It's Done!
    </ng-template>

    <ng-template #iAmNotDone>
      It's Not Done!
    </ng-template>

unique combinations of values in selected columns in pandas data frame and count

Slightly related, I was looking for the unique combinations and I came up with this method:

def unique_columns(df,columns):

    result = pd.Series(index = df.index)

    groups = meta_data_csv.groupby(by = columns)
    for name,group in groups:
       is_unique = len(group) == 1
       result.loc[group.index] = is_unique

    assert not result.isnull().any()

    return result

And if you only want to assert that all combinations are unique:

df1.set_index(['A','B']).index.is_unique

C++ convert string to hexadecimal and vice versa

Using lookup tables and the like works, but is just overkill, here are some very simple ways of taking a string to hex and hex back to a string:

#include <stdexcept>
#include <sstream>
#include <iomanip>
#include <string>
#include <cstdint>

std::string string_to_hex(const std::string& in) {
    std::stringstream ss;

    ss << std::hex << std::setfill('0');
    for (size_t i = 0; in.length() > i; ++i) {
        ss << std::setw(2) << static_cast<unsigned int>(static_cast<unsigned char>(in[i]));
    }

    return ss.str(); 
}

std::string hex_to_string(const std::string& in) {
    std::string output;

    if ((in.length() % 2) != 0) {
        throw std::runtime_error("String is not valid length ...");
    }

    size_t cnt = in.length() / 2;

    for (size_t i = 0; cnt > i; ++i) {
        uint32_t s = 0;
        std::stringstream ss;
        ss << std::hex << in.substr(i * 2, 2);
        ss >> s;

        output.push_back(static_cast<unsigned char>(s));
    }

    return output;
}

Add line break within tooltips

So if you are using bootstrap4 then this will work.

<style>
   .tooltip-inner {
    white-space: pre-wrap;
   }

</style>

<script> 
    $(function () {
      $('[data-toggle="tooltip"]').tooltip()
    })
</script>

<a data-toggle="tooltip" data-placement="auto" title=" first line &#010; next line" href= ""> Hover me </a>

If you are using in Django project then we can also display dynamic data in tooltips like:

<a class="black-text pb-2 pt-1" data-toggle="tooltip" data-placement="auto"  title="{{ post.location }} &#010; {{ post.updated_on }}" href= "{% url 'blog:get_user_profile' post.author.id %}">{{ post.author }}</a>

Catch multiple exceptions at once?

This is a classic problem every C# developer faces eventually.

Let me break your question into 2 questions. The first,

Can I catch multiple exceptions at once?

In short, no.

Which leads to the next question,

How do I avoid writing duplicate code given that I can't catch multiple exception types in the same catch() block?

Given your specific sample, where the fall-back value is cheap to construct, I like to follow these steps:

  1. Initialize WebId to the fall-back value.
  2. Construct a new Guid in a temporary variable.
  3. Set WebId to the fully constructed temporary variable. Make this the final statement of the try{} block.

So the code looks like:

try
{
    WebId = Guid.Empty;
    Guid newGuid = new Guid(queryString["web"]);
    // More initialization code goes here like 
    // newGuid.x = y;
    WebId = newGuid;
}
catch (FormatException) {}
catch (OverflowException) {}

If any exception is thrown, then WebId is never set to the half-constructed value, and remains Guid.Empty.

If constructing the fall-back value is expensive, and resetting a value is much cheaper, then I would move the reset code into its own function:

try
{
    WebId = new Guid(queryString["web"]);
    // More initialization code goes here.
}
catch (FormatException) {
    Reset(WebId);
}
catch (OverflowException) {
    Reset(WebId);
}

How do I return multiple values from a function in C?

I don't know what your string is, but I'm going to assume that it manages its own memory.

You have two solutions:

1: Return a struct which contains all the types you need.

struct Tuple {
    int a;
    string b;
};

struct Tuple getPair() {
    Tuple r = { 1, getString() };
    return r;
}

void foo() {
    struct Tuple t = getPair();
}

2: Use pointers to pass out values.

void getPair(int* a, string* b) {
    // Check that these are not pointing to NULL
    assert(a);
    assert(b);
    *a = 1;
    *b = getString();
}

void foo() {
    int a, b;
    getPair(&a, &b);
}

Which one you choose to use depends largely on personal preference as to whatever semantics you like more.

How to use JavaScript source maps (.map files)?

The map file maps the unminified file to the minified file. If you make changes in the unminified file, the changes will be automatically reflected to the minified version of the file.

How do I define global variables in CoffeeScript?

You can pass -b option when you compile code via coffee-script under node.js. The compiled code will be the same as on coffeescript.org.

What 'additional configuration' is necessary to reference a .NET 2.0 mixed mode assembly in a .NET 4.0 project?

I Use

<startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0"/>
    <supportedRuntime version="v2.0.50727"/>
</startup>

It's works but just before de </configuration> tag otherwise the startup tag doesn't work properly

How to change the current URL in javascript?

Your example wasn't working because you are trying to add 1 to a string that looks like this: "1.html". That will just get you this "1.html1" which is not what you want. You have to isolate the numeric part of the string and then convert it to an actual number before you can do math on it. After getting it to an actual number, you can then increase its value and then combine it back with the rest of the string.

You can use a custom replace function like this to isolate the various pieces of the original URL and replace the number with an incremented number:

function nextImage() {
    return(window.location.href.replace(/(\d+)(\.html)$/, function(str, p1, p2) {
        return((Number(p1) + 1) + p2);
    }));
}

You can then call it like this:

window.location.href = nextImage();

Demo here: http://jsfiddle.net/jfriend00/3VPEq/

This will work for any URL that ends in some series of digits followed by .html and if you needed a slightly different URL form, you could just tweak the regular expression.

Pass a PHP string to a JavaScript variable (and escape newlines)

The paranoid version: Escaping every single character.

function javascript_escape($str) {
  $new_str = '';

  $str_len = strlen($str);
  for($i = 0; $i < $str_len; $i++) {
    $new_str .= '\\x' . sprintf('%02x', ord(substr($str, $i, 1)));
  }

  return $new_str;
}

EDIT: The reason why json_encode() may not be appropriate is that sometimes, you need to prevent " to be generated, e.g.

<div onclick="alert(???)" />

How to configure Glassfish Server in Eclipse manually

This questions seems a little bit outdated but here is my solution.

I assume that you have already downloaded GlassFish on your hard drive and unzipped the files on a directory.

A - Eclipse MarketPlace / Installing GlassFish Tools

The first thing as it is said on previous answers, you have to downloaded GlassFish Tools from eclipse marketplace;

Help -> EclipseMarket Place

enter image description here

And install GlassFish on the screen below;

enter image description here

B - Adding GlassFish Server

Open Server View, if it is not visible on the bottom of the eclipse, then;

Window -> Show View -> Servers

enter image description here

As the server view is visible, simply click "No servers are available. Click this link to create a new server..." as shown below;

enter image description here

C - Adding GlassFish Server

On the New Server window, select GlassFish as shown below. On my experience, there is only one GlassFish option that I can select, instead of several GlassFish options with versions as you can see down below;

enter image description here

D - Configuring GlassFish & Java Locations

Enter the exact GlassFish location and also Java location as you can see below;

enter image description here

E - Last Step

On the last step of this configuration, just leave everything as it is. For simplicity, I don't define an admin password;

enter image description here

Now everything is all set, hope that this helps!

Simple way to repeat a string

I created a recursive method that do the same thing you want.. feel free to use this...

public String repeat(String str, int count) {
    return count > 0 ?  repeat(str, count -1) + str: "";
}

i have the same answer on Can I multiply strings in java to repeat sequences?

Using IF ELSE statement based on Count to execute different Insert statements

Simply use the following:

IF((SELECT count(*) FROM table)=0)
BEGIN

....

END

Getting Error - ORA-01858: a non-numeric character was found where a numeric was expected

I added TO_DATE and it resolved issue.

Before modification - due to below condition i got this error

record_update_dt>='05-May-2017'

After modification - after adding to_date, issue got resolved.

record_update_dt>=to_date('05-May-2017','DD-Mon-YYYY')

Launching Spring application Address already in use

This error basically happens when the specific port is not free. So there are two solutions, you can free that port by killing or closing the service which is using it or you can run your application (tomcat) on a different port.

Solution 1: Free the port

On a Linux machine you can find the process-id of port's consumer and then kill it. Use the following command (it is assume that the default port is 8080)

netstat -pnltu | grep -i "8080"

The output of the above-mentioned command would be something like:

tcp6   0  0 :::8080    :::*      LISTEN      20674/java 

Then you can easily kill the process with its processid:

kill 20674

On a windows machine to find a processid use netstat -ano -p tcp |find "8080". To kill the process use taskkill /F /PID 1234 (instead of 1234 enter the founded processid).

Solution 2: Change the default port

In the development process developers use the port 8080 that you can change it easily. You need to specify your desired port number in the application.properties file of your project (/src/main/resources/application.properties) by using the following specification:

server.port=8081

You can also set an alternative port number while executing the .jar file

- java -jar spring-boot-application.jar --server.port=8081

Please notice that sometimes (not necessarily) you have to change other ports too like:

management.port=
tomcat.jvmroute=
tomcat.ajp.port=
tomcat.ajp.redirectPort=
etc...

Flutter- wrapping text

Try Wrap widget to wrap text as text grows:

Example:

Wrap(
  direction: Axis.vertical, //Vertical || Horizontal
  children: <Widget>[
    Text(
      'Your Text',
      style: TextStyle(fontSize: 30),
    ),
    Text(
      'Your Text',
      style: TextStyle(fontSize: 30),
    ),
  ],
),

How to edit hosts file via CMD?

echo 0.0.0.0 websitename.com >> %WINDIR%\System32\Drivers\Etc\Hosts

the >> appends the output of echo to the file.

Note that there are two reasons this might not work like you want it to. You may be aware of these, but I mention them just in case.

First, it won't affect a web browser, for example, that already has the current, "real" IP address resolved. So, it won't always take effect right away.

Second, it requires you to add an entry for every host name on a domain; just adding websitename.com will not block www.websitename.com, for example.

load scripts asynchronously

I loaded the scripts asynchronously (html 5 has that feature) when all the scripts where done loading I redirected the page to index2.html where index2.html uses the same libraries. Because browsers have a cache once the page redirects to index2.html, index2.html loads in less than a second because it has all it needs to load the page. In my index.html page I also load the images that I plan on using so that the browser place those images on the cache. so my index.html looks like:

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
    <title>Project Management</title>

    <!-- the purpose of this page is to load all the scripts on the browsers cache so that pages can load fast from now on -->

    <script type="text/javascript">

        function stylesheet(url) {
            var s = document.createElement('link');
            s.type = 'text/css';
            s.async = true;
            s.src = url;
            var x = document.getElementsByTagName('head')[0];
            x.appendChild(s);
        }

        function script(url) {
            var s = document.createElement('script');
            s.type = 'text/javascript';
            s.async = true;
            s.src = url;
            var x = document.getElementsByTagName('head')[0];
            x.appendChild(s);
        }

        //load scritps to the catche of browser
        (function () {            
                stylesheet('css/custom-theme/jquery-ui-1.8.16.custom.css');
                stylesheet('css/main.css');
                stylesheet('css/marquee.css');
                stylesheet('css/mainTable.css');

                script('js/jquery-ui-1.8.16.custom.min.js');
                script('js/jquery-1.6.2.min.js');
                script('js/myFunctions.js');
                script('js/farinspace/jquery.imgpreload.min.js');
                script('js/marquee.js');            
        })();

    </script>

    <script type="text/javascript">
       // once the page is loaded go to index2.html
        window.onload = function () {
            document.location = "index2.html";
        }
    </script>

</head>
<body>

<div id="cover" style="position:fixed; left:0px; top:0px; width:100%; height:100%; background-color:Black; z-index:100;">Loading</div>

<img src="images/home/background.png" />
<img src="images/home/3.png"/>
<img src="images/home/6.jpg"/>
<img src="images/home/4.png"/>
<img src="images/home/5.png"/>
<img src="images/home/8.jpg"/>
<img src="images/home/9.jpg"/>
<img src="images/logo.png"/>
<img src="images/logo.png"/>
<img src="images/theme/contentBorder.png"/>

</body>
</html>

another nice thing about this is that I may place a loader in the page and when the page is done loading the loader will go away and in a matte of milliseconds the new page will be running.

SQL Server Operating system error 5: "5(Access is denied.)"

For some reason, setting all the correct permissions did not help in my case. I had a file db.bak that I was not able to restore due to the 5(Access is denied.) error. The file was placed in the same folder as several other backup files and all the permissions were identical to other files. I was able to restore all the other files except this db.bak file. I even tried to change the SQL Server service log on user — still the same result. I've tried copying the file with no effect.

Then I attempted to just create an identical file by executing

type db.bak > db2.bak

instead of copying the file. And voila it worked! db2.bak restored successfully.

I suspect that some other problems with reading the backup file may be erroniously reported as 5(Access is denied.) by MS SQL.

How to build minified and uncompressed bundle with webpack?

webpack.config.js:

const webpack = require("webpack");

module.exports = {
  entry: {
    "bundle": "./entry.js",
    "bundle.min": "./entry.js",
  },
  devtool: "source-map",
  output: {
    path: "./dist",
    filename: "[name].js"
  },
  plugins: [
    new webpack.optimize.UglifyJsPlugin({
      include: /\.min\.js$/,
      minimize: true
    })
  ]
};

Since Webpack 4, webpack.optimize.UglifyJsPlugin has been deprecated and its use results in error:

webpack.optimize.UglifyJsPlugin has been removed, please use config.optimization.minimize instead

As the manual explains, the plugin can be replaced with minimize option. Custom configuration can be provided to the plugin by specifying UglifyJsPlugin instance:

const webpack = require("webpack");
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = {
  // ...
  optimization: {
    minimize: true,
    minimizer: [new UglifyJsPlugin({
      include: /\.min\.js$/
    })]
  }
};

This does the job for a simple setup. A more effective solution is to use Gulp together with Webpack and do the same thing in one pass.

Convert time fields to strings in Excel

This kind of this is always a pain in Excel, you have to convert the values using a function because once Excel converts the cells to Time they are stored internally as numbers. Here is the best way I know how to do it:

I'll assume that your times are in column A starting at row 1. In cell B1 enter this formula: =TEXT(A1,"hh:mm:ss AM/PM") , drag the formula down column B to the end of your data in column A. Select the values from column B, copy, go to column C and select "Paste Special", then select "Values". Select the cells you just copied into column C and format the cells as "Text".

What's the difference between django OneToOneField and ForeignKey?

ForeignKey allows you receive subclasses is it definition of another class but OneToOneFields cannot do this and it is not attachable to multiple variables

Selecting option by text content with jQuery

I know this question is too old, but still, I think this approach would be cleaner:

cat = $.URLDecode(cat);
$('#cbCategory option:contains("' + cat + '")').prop('selected', true);

In this case you wont need to go over the entire options with each(). Although by that time prop() didn't exist so for older versions of jQuery use attr().


UPDATE

You have to be certain when using contains because you can find multiple options, in case of the string inside cat matches a substring of a different option than the one you intend to match.

Then you should use:

cat = $.URLDecode(cat);
$('#cbCategory option')
    .filter(function(index) { return $(this).text() === cat; })
    .prop('selected', true);

Move an item inside a list?

A slightly shorter solution, that only moves the item to the end, not anywhere is this:

l += [l.pop(0)]

For example:

>>> l = [1,2,3,4,5]
>>> l += [l.pop(0)]
>>> l
[2, 3, 4, 5, 1]

Remove Top Line of Text File with PowerShell

I just learned from a website:

Get-ChildItem *.txt | ForEach-Object { (get-Content $_) | Where-Object {(1) -notcontains $_.ReadCount } | Set-Content -path $_ }

Or you can use the aliases to make it short, like:

gci *.txt | % { (gc $_) | ? { (1) -notcontains $_.ReadCount } | sc -path $_ }

How to remove multiple deleted files in Git repository

Yes, git rm <filename> will stage the deleted state of a file, where <filename> could be a glob pattern:

$ git rm modules/welcome/language/*/kaimonokago_lang.php
rm modules/welcome/language/english/kaimonokago_lang.php
rm modules/welcome/language/french/kaimonokago_lang.php
rm modules/welcome/language/german/kaimonokago_lang.php
rm modules/welcome/language/norwegian/kaimonokago_lang.php

$ git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#       deleted:    modules/welcome/language/english/kaimonokago_lang.php
#       ...

Then, you can commit.

git commit -a will do this in one go, if you want.

You can also use git add -u to stage all the changes, including all the deleted files, then commit.

How to send a compressed archive that contains executables so that Google's attachment filter won't reject it

Try this:

tar -czf my.tar.gz dir/

But are you sure you are not compressing some .exe file or something? Maybe the problem is not with te compression, but with the files you are compressing?

convert string to specific datetime format?

"2011-05-19 10:30:14".to_time

How to lose margin/padding in UITextView?

For SwiftUI

If you are making your own TextView using UIViewRepresentable and want to control the padding, in your makeUIView function, simply do:

uiTextView.textContainerInset = UIEdgeInsets(top: 10, left: 18, bottom: 0, right: 18)

or whatever you want.

Using JQuery to open a popup window and print

Got it! I found an idea here

http://www.mail-archive.com/[email protected]/msg18410.html

In this example, they loaded a blank popup window into an object, cloned the contents of the element to be displayed, and appended it to the body of the object. Since I already knew what the contents of view-details (or any page I load in the lightbox), I just had to clone that content instead and load it into an object. Then, I just needed to print that object. The final outcome looks like this:

$('.printBtn').bind('click',function() {
    var thePopup = window.open( '', "Customer Listing", "menubar=0,location=0,height=700,width=700" );
    $('#popup-content').clone().appendTo( thePopup.document.body );
    thePopup.print();
});

I had one small drawback in that the style sheet I was using in view-details.php was using a relative link. I had to change it to an absolute link. The reason being that the window didn't have a URL associated with it, so it had no relative position to draw on.

Works in Firefox. I need to test it in some other major browsers too.

I don't know how well this solution works when you're dealing with images, videos, or other process intensive solutions. Although, it works pretty well in my case, since I'm just loading tables and text values.

Thanks for the input! You gave me some ideas of how to get around this.

Undefined reference to pthread_create in Linux

If you are using cmake, you can use:

add_compile_options(-pthread)

Or

SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")

Import XXX cannot be resolved for Java SE standard classes

If by chance you have deleted JRE SYSTEM LIBRARY, then go to your JRE installation and add jars from there.

Eg:- C:\Program Files (x86)\Java\jre7\lib ---add jars from here

C:\Program Files (x86)\Java\jre7\lib\ext ---add jars from here

image size (drawable-hdpi/ldpi/mdpi/xhdpi)

I have a full explanation already posted here

Basically, General guidelines for designing images are:

ldpi is 0.75x dimensions of mdpi
hdpi is 1.5x dimensions of mdpi
xhdpi is 2x dimensinons of mdpi

Usually, I design mdpi images for a 320x480 screen and then multiply the dimensions as per the above rules to get images for other resolutions.

Please refer to the full explanation for a more detailed answer.

How to read a single char from the console in Java (as the user types it)?

I have written a Java class RawConsoleInput that uses JNA to call operating system functions of Windows and Unix/Linux.

  • On Windows it uses _kbhit() and _getwch() from msvcrt.dll.
  • On Unix it uses tcsetattr() to switch the console to non-canonical mode, System.in.available() to check whether data is available and System.in.read() to read bytes from the console. A CharsetDecoder is used to convert bytes to characters.

It supports non-blocking input and mixing raw mode and normal line mode input.

mysqldump data only

Would suggest using the following snippet. Works fine even with huge tables (otherwise you'd open dump in editor and strip unneeded stuff, right? ;)

mysqldump --no-create-info --skip-triggers --extended-insert --lock-tables --quick DB TABLE > dump.sql

At least mysql 5.x required, but who runs old stuff nowadays.. :)

How can I convert this one line of ActionScript to C#?

There is collection of Func<...> classes - Func that is probably what you are looking for:

 void MyMethod(Func<int> param1 = null) 

This defines method that have parameter param1 with default value null (similar to AS), and a function that returns int. Unlike AS in C# you need to specify type of the function's arguments.

So if you AS usage was

MyMethod(function(intArg, stringArg) { return true; }) 

Than in C# it would require param1 to be of type Func<int, siring, bool> and usage like

MyMethod( (intArg, stringArg) => { return true;} ); 

How to encode the plus (+) symbol in a URL

Is you want a plus (+) symbol in the body you have to encode it as 2B.

For example: Try this

PHP $_POST not working?

Instead of using $_POST, use $_REQUEST:

HTML:

<form action="" method="post">
  <input type="text" name="firstname">
  <input type="submit" name="submit" value="Submit">
</form>

PHP:

if(isset($_REQUEST['submit'])){
  $test = $_REQUEST['firstname'];
  echo $test;
}

error_reporting(E_ALL) does not produce error

In your php.ini file check for display_errors. If it is off, then make it on as below:

display_errors = On

It should display warnings/notices/errors .

Please read this

http://www.php.net/manual/en/errorfunc.configuration.php#ini.error-reporting

Using an image caption in Markdown Jekyll

The correct HTML to use for images with captions, is <figure> with <figcaption>.

There's no Markdown equivalent for this, so if you're only adding the occasional caption, I'd encourage you to just add that html into your Markdown document:

Lorem ipsum dolor sit amet, consectetur adipiscing elit...

<figure>
  <img src="{{site.url}}/assets/image.jpg" alt="my alt text"/>
  <figcaption>This is my caption text.</figcaption>
</figure>

Vestibulum eu vulputate magna...

The Markdown spec encourages you to embed HTML in cases like this, so it will display just fine. It's also a lot simpler than messing with plugins.

If you're trying to use other Markdown-y features (like tables, asterisks, etc) to produce captions, then you're just hacking around how Markdown was intended to be used.

Update only specific fields in a models.Model

Usually, the correct way of updating certain fields in one or more model instances is to use the update() method on the respective queryset. Then you do something like this:

affected_surveys = Survey.objects.filter(
    # restrict your queryset by whatever fits you
    # ...
    ).update(active=True)

This way, you don't need to call save() on your model anymore because it gets saved automatically. Also, the update() method returns the number of survey instances that were affected by your update.

AVD Manager - Cannot Create Android Virtual Device

Another thing that tripped me up: the "Name" field must be a single word and must not have spaces!

What does \0 stand for?

In C \0 is a character literal constant store into an int data type that represent the character with value of 0.

Since Objective-C is a strict superset of C this constant is retained.

Where to find extensions installed folder for Google Chrome on Mac?

The default locations of Chrome's profile directory are defined at http://www.chromium.org/user-experience/user-data-directory. For Chrome on Mac, it's

~/Library/Application\ Support/Google/Chrome/Default

The actual location can be different, by setting the --user-data-dir=path/to/directory flag.
If only one user is registered in Chrome, look in the Default/Extensions subdirectory. Otherwise, look in the <profile user name>/Extensions directory.

If that didn't help, you can always do a custom search.

  1. Go to chrome://extensions/, and find out the ID of an extension (32 lowercase letters) (if not done already, activate "Developer mode" first).

  2. Open the terminal, cd to the directory which is most likely a parent of your Chrome profile (if unsure, try ~ then /).

  3. Run find . -type d -iname "<EXTENSION ID HERE>", for example:

    find . -type d -iname jifpbeccnghkjeaalbbjmodiffmgedin
    

    Result:

    ./Library/Application Support/Google/Chrome/Default/Extensions/jifpbeccnghkjeaalbbjmodiffmgedin

Media Queries - In between two widths

_x000D_
_x000D_
.class {_x000D_
    display: none;_x000D_
}_x000D_
@media (min-width:400px) and (max-width:900px) {_x000D_
    .class {_x000D_
        display: block; /* just an example display property */_x000D_
    }_x000D_
}
_x000D_
_x000D_
_x000D_

Return char[]/string from a function

Notice you're not dynamically allocating the variable, which pretty much means the data inside str, in your function, will be lost by the end of the function.

You should have:

char * createStr() {

    char char1= 'm';
    char char2= 'y';

    char *str = malloc(3);
    str[0] = char1;
    str[1] = char2;
    str[2] = '\0';

    return str;

}

Then, when you call the function, the type of the variable that will receive the data must match that of the function return. So, you should have:

char *returned_str = createStr();

It worths mentioning that the returned value must be freed to prevent memory leaks.

char *returned_str = createStr();

//doSomething
...

free(returned_str);

How to select a single field for all documents in a MongoDB collection?

db.<collection>.find({}, {field1: <value>, field2: <value> ...})

In your example, you can do something like:

db.students.find({}, {"roll":true, "_id":false})

Projection

The projection parameter determines which fields are returned in the matching documents. The projection parameter takes a document of the following form:

{ field1: <value>, field2: <value> ... }
The <value> can be any of the following:
  1. 1 or true to include the field in the return documents.

  2. 0 or false to exclude the field.

NOTE

For the _id field, you do not have to explicitly specify _id: 1 to return the _id field. The find() method always returns the _id field unless you specify _id: 0 to suppress the field.

READ MORE

SSH Private Key Permissions using Git GUI or ssh-keygen are too open

You changed the permissions on the whole directory, which I agree with Splash is a bad idea. If you can remember what the original permissions for the directory are, I would try to set them back to that and then do the following

cd ~/.ssh
chmod 700 id_rsa

inside the .ssh folder. That will set the id_rsa file to rwx (read, write, execute) for the owner (you) only, and zero access for everyone else.

If you can't remember what the original settings are, add a new user and create a set of SSH keys for that user, thus creating a new .ssh folder which will have default permissions. You can use that new .ssh folder as the reference for permissions to reset your .ssh folder and files to.

If that doesn't work, I would try doing an uninstall of msysgit, deleting ALL .ssh folders on the computer (just for safe measure), then reinstalling msysgit with your desired settings and try starting over completely (though I think you told me you tried this already).

Edited: Also just found this link via Google -- Fixing "WARNING: UNPROTECTED PRIVATE KEY FILE!" on Linux While it's targeted at linux, it might help since we're talking liunx permissions and such.

Is it more efficient to copy a vector by reserving and copying, or by creating and swapping?

This is another valid way to make a copy of a vector, just use its constructor:

std::vector<int> newvector(oldvector);

This is even simpler than using std::copy to walk the entire vector from start to finish to std::back_insert them into the new vector.

That being said, your .swap() one is not a copy, instead it swaps the two vectors. You would modify the original to not contain anything anymore! Which is not a copy.

Removing the first 3 characters from a string

Use the substring method of the String class :

String removeCurrency=amount.getText().toString().substring(3);

How do I get the value of text input field using JavaScript?

//creates a listener for when you press a key
window.onkeyup = keyup;

//creates a global Javascript variable
var inputTextValue;

function keyup(e) {
  //setting your input text to the global Javascript Variable for every key press
  inputTextValue = e.target.value;

  //listens for you to press the ENTER key, at which point your web address will change to the one you have input in the search box
  if (e.keyCode == 13) {
    window.location = "http://www.myurl.com/search/" + inputTextValue;
  }
}

See this functioning in codepen.

What are NDF Files?

From Files and Filegroups Architecture

Secondary data files

Secondary data files make up all the data files, other than the primary data file. Some databases may not have any secondary data files, while others have several secondary data files. The recommended file name extension for secondary data files is .ndf.

Also from file extension NDF - Microsoft SQL Server secondary data file

See Understanding Files and Filegroups

Secondary data files are optional, are user-defined, and store user data. Secondary files can be used to spread data across multiple disks by putting each file on a different disk drive. Additionally, if a database exceeds the maximum size for a single Windows file, you can use secondary data files so the database can continue to grow.

The recommended file name extension for secondary data files is .ndf.

/

For example, three files, Data1.ndf, Data2.ndf, and Data3.ndf, can be created on three disk drives, respectively, and assigned to the filegroup fgroup1. A table can then be created specifically on the filegroup fgroup1. Queries for data from the table will be spread across the three disks; this will improve performance. The same performance improvement can be accomplished by using a single file created on a RAID (redundant array of independent disks) stripe set. However, files and filegroups let you easily add new files to new disks.

What static analysis tools are available for C#?

Aside from the excellent list by madgnome, I would add a duplicate code detector that is based off the command line (but is free):

http://sourceforge.net/projects/duplo/

How to do a Postgresql subquery in select clause with join in from clause like SQL Server?

I am just answering here with the formatted version of the final sql I needed based on Bob Jarvis answer as posted in my comment above:

select n1.name, n1.author_id, cast(count_1 as numeric)/total_count
  from (select id, name, author_id, count(1) as count_1
          from names
          group by id, name, author_id) n1
inner join (select author_id, count(1) as total_count
              from names
              group by author_id) n2
  on (n2.author_id = n1.author_id)

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

No.

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

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

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

Hence:

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

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

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

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

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

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

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

Get all column names of a DataTable into string array using (LINQ/Predicate)

List<String> lsColumns = new List<string>();

if(dt.Rows.Count>0)
{
    var count = dt.Rows[0].Table.Columns.Count;

    for (int i = 0; i < count;i++ )
    {
        lsColumns.Add(Convert.ToString(dt.Rows[0][i]));
    }
}

How to get a resource id with a known resource name?

I have found this class very helpful to handle with resources. It has some defined methods to deal with dimens, colors, drawables and strings, like this one:

public static String getString(Context context, String stringId) {
    int sid = getStringId(context, stringId);
    if (sid > 0) {
        return context.getResources().getString(sid);
    } else {
        return "";
    }
}

What are the date formats available in SimpleDateFormat class?

java.time

UPDATE

The other Questions are outmoded. The terrible legacy classes such as SimpleDateFormat were supplanted years ago by the modern java.time classes.

Custom

For defining your own custom formatting patterns, the codes in DateTimeFormatter are similar to but not exactly the same as the codes in SimpleDateFormat. Be sure to study the documentation. And search Stack Overflow for many examples.

DateTimeFormatter f = 
    DateTimeFormatter.ofPattern( 
        "dd MMM uuuu" , 
        Locale.ITALY 
    ) 
;

Standard ISO 8601

The ISO 8601 standard defines formats for many types of date-time values. These formats are designed for data-exchange, being easily parsed by machine as well as easily read by humans across cultures.

The java.time classes use ISO 8601 formats by default when generating/parsing strings. Simply call the toString & parse methods. No need to specify a formatting pattern.

Instant.now().toString()

2018-11-05T18:19:33.017554Z

For a value in UTC, the Z on the end means UTC, and is pronounced “Zulu”.

Localize

Rather than specify a formatting pattern, you can let java.time automatically localize for you. Use the DateTimeFormatter.ofLocalized… methods.

Get current moment with the wall-clock time used by the people of a particular region (a time zone).

ZoneId z = ZoneId.of( "Africa/Tunis" );
ZonedDateTime zdt = ZonedDateTime.now( z );

Generate text in standard ISO 8601 format wisely extended to append the name of the time zone in square brackets.

zdt.toString(): 2018-11-05T19:20:23.765293+01:00[Africa/Tunis]

Generate auto-localized text.

Locale locale = Locale.CANADA_FRENCH;
DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.FULL ).withLocale( locale );

String output = zdt.format( f );

output: lundi 5 novembre 2018 à 19:20:23 heure normale d’Europe centrale

Generally a better practice to auto-localize rather than fret with hard-coded formatting patterns.


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.

Where to obtain the java.time classes?

What is the purpose of shuffling and sorting phase in the reducer in Map Reduce Programming?

I thought of just adding some points missing in above answers. This diagram taken from here clearly states the what's really going on.

enter image description here

If I state again the real purpose of

  • Split: Improves the parallel processing by distributing the processing load across different nodes (Mappers), which would save the overall processing time.

  • Combine: Shrinks the output of each Mapper. It would save the time spending for moving the data from one node to another.

  • Sort (Shuffle & Sort): Makes it easy for the run-time to schedule (spawn/start) new reducers, where while going through the sorted item list, whenever the current key is different from the previous, it can spawn a new reducer.

How to convert CSV file to multiline JSON?

I took @SingleNegationElimination's response and simplified it into a three-liner that can be used in a pipeline:

import csv
import json
import sys

for row in csv.DictReader(sys.stdin):
    json.dump(row, sys.stdout)
    sys.stdout.write('\n')

How to change the name of a Django app?

In many cases, I believe @allcaps's answer works well.

However, sometimes it is necessary to actually rename an app, e.g. to improve code readability or prevent confusion.

Most of the other answers involve either manual database manipulation or tinkering with existing migrations, which I do not like very much.

As an alternative, I like to create a new app with the desired name, copy everything over, make sure it works, then remove the original app:

  1. Start a new app with the desired name, and copy all code from the original app into that. Make sure you fix the namespaced stuff, in the newly copied code, to match the new app name.

  2. makemigrations and migrate

  3. Create a data migration that copies the relevant data from the original app's tables into the new app's tables, and migrate again.

At this point, everything still works, because the original app and its data are still in place.

  1. Now you can refactor all the dependent code, so it only makes use of the new app. See other answers for examples of what to look out for.

  2. Once you are certain that everything works, you can remove the original app.

This has the advantage that every step uses the normal Django migration mechanism, without manual database manipulation, and we can track everything in source control. In addition, we keep the original app and its data in place until we are sure everything works.

How to declare a global variable in a .js file

As mentioned above, there are issues with using the top-most scope in your script file. Here is another issue: The script file might be run from a context that is not the global context in some run-time environment.

It has been proposed to assign the global to window directly. But that is also run-time dependent and does not work in Node etc. It goes to show that portable global variable management needs some careful consideration and extra effort. Maybe they will fix it in future ECMS versions!

For now, I would recommend something like this to support proper global management for all run-time environments:

/**
 * Exports the given object into the global context.
 */
var exportGlobal = function(name, object) {
    if (typeof(global) !== "undefined")  {
        // Node.js
        global[name] = object;
    }
    else if (typeof(window) !== "undefined") {
        // JS with GUI (usually browser)
        window[name] = object;
    }
    else {
        throw new Error("Unkown run-time environment. Currently only browsers and Node.js are supported.");
    }
};


// export exportGlobal itself
exportGlobal("exportGlobal", exportGlobal);

// create a new global namespace
exportGlobal("someothernamespace", {});

It's a bit more typing, but it makes your global variable management future-proof.

Disclaimer: Part of this idea came to me when looking at previous versions of stacktrace.js.

I reckon, one can also use Webpack or other tools to get more reliable and less hackish detection of the run-time environment.

Composer require runs out of memory. PHP Fatal error: Allowed memory size of 1610612736 bytes exhausted

Make sure to not require a package before making sure the vendor folder exists.

Check if you have done composer install before. You may be just cloned the repository to your machine. So, you have to install the old packages before requiring a new one. Or you may want to include this option --profile to your composer command to see the timing and memory usage information.

What does MVW stand for?

MVW stands for Model-View-Whatever.

For completeness, here are all the acronyms mentioned:

MVC - Model-View-Controller

MVP - Model-View-Presenter

MVVM - Model-View-ViewModel

MVW / MV* / MVx - Model-View-Whatever

And some more:

HMVC - Hierarchical Model-View-Controller

MMV - Multiuse Model View

MVA - Model-View-Adapter

MVI - Model-View-Intent

angular 2 sort and filter

You must create your own Pipe for array sorting, here is one example how can you do that.

<li *ngFor="#item of array | arraySort:'-date'">{{item.name}} {{item.date | date:'medium' }}</li>

https://plnkr.co/edit/DU6pxr?p=preview

Razor If/Else conditional operator syntax

You need to put the entire ternary expression in parenthesis. Unfortunately that means you can't use "@:", but you could do something like this:

@(deletedView ? "Deleted" : "Created by")

Razor currently supports a subset of C# expressions without using @() and unfortunately, ternary operators are not part of that set.

What is the difference between encode/decode?

The simple answer is that they are the exact opposite of each other.

The computer uses the very basic unit of byte to store and process information; it is meaningless for human eyes.

For example,'\xe4\xb8\xad\xe6\x96\x87' is the representation of two Chinese characters, but the computer only knows (meaning print or store) it is Chinese Characters when they are given a dictionary to look for that Chinese word, in this case, it is a "utf-8" dictionary, and it would fail to correctly show the intended Chinese word if you look into a different or wrong dictionary (using a different decoding method).

In the above case, the process for a computer to look for Chinese word is decode().

And the process of computer writing the Chinese into computer memory is encode().

So the encoded information is the raw bytes, and the decoded information is the raw bytes and the name of the dictionary to reference (but not the dictionary itself).

Export to csv in jQuery

Here are two WORKAROUNDS to the problem of triggering downloads from the client only. In later browsers you should look at "blob"


1. Drag and drop the table

Did you know you can simply DRAG your table into excel?

Here is how to select the table to either cut and past or drag

Select a complete table with Javascript (to be copied to clipboard)


2. create a popup page from your div

Although it will not produce a save dialog, if the resulting popup is saved with extension .csv, it will be treated correctly by Excel.

The string could be
w.document.write("row1.1\trow1.2\trow1.3\nrow2.1\trow2.2\trow2.3");
e.g. tab-delimited with a linefeed for the lines.

There are plugins that will create the string for you - such as http://plugins.jquery.com/project/table2csv

var w = window.open('','csvWindow'); // popup, may be blocked though
// the following line does not actually do anything interesting with the 
// parameter given in current browsers, but really should have. 
// Maybe in some browser it will. It does not hurt anyway to give the mime type
w.document.open("text/csv");
w.document.write(csvstring); // the csv string from for example a jquery plugin
w.document.close();

DISCLAIMER: These are workarounds, and does not fully answer the question which currently has the answer for most browser: not possible on the client only

How to use LINQ Distinct() with multiple fields

Use the Key keyword in your select will work, like below.

product.Select(m => new {Key m.CategoryId, Key m.CategoryName}).Distinct();

I realize this is bringing up an old thread but figured it might help some people. I generally code in VB.NET when working with .NET so Key may translate differently into C#.

What is the largest Safe UDP Packet Size on the Internet

The maximum safe UDP payload is 508 bytes. This is a packet size of 576 (the "minimum maximum reassembly buffer size"), minus the maximum 60-byte IP header and the 8-byte UDP header.

Any UDP payload this size or smaller is guaranteed to be deliverable over IP (though not guaranteed to be delivered). Anything larger is allowed to be outright dropped by any router for any reason. Except on an IPv6-only route, where the maximum payload is 1,212 bytes. As others have mentioned, additional protocol headers could be added in some circumstances. A more conservative value of around 300-400 bytes may be preferred instead.

The maximum possible UDP payload is 67 KB, split into 45 IP packets, adding an additional 900 bytes of overhead (IPv4, MTU 1500, minimal 20-byte IP headers).

Any UDP packet may be fragmented. But this isn't too important, because losing a fragment has the same effect as losing an unfragmented packet: the entire packet is dropped. With UDP, this is going to happen either way.

IP packets include a fragment offset field, which indicates the byte offset of the UDP fragment in relation to its UDP packet. This field is 13-bit, allowing 8,192 values, which are in 8-byte units. So the range of such offsets an IP packet can refer to is 0...65,528 bytes. Being an offset, we add 1,480 for the last UDP fragment to get 67,008. Minus the UDP header in the first fragment gives us a nice, round 67 KB.

Sources: RFC 791, RFC 1122, RFC 2460

how to align text vertically center in android

just use like this to make anything to center

 android:layout_gravity="center"
 android:gravity="center"

updated :

android:layout_gravity="center|right"
android:gravity="center|right"

Updated : Just remove MarginBottom from your textview.. Do like this.. for your textView

<LinearLayout
        android:id="@+id/linearLayout5"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"  >

        <TextView
            android:id="@+id/textView2"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center" 
            android:gravity="center|right"
            android:text="hello" 
            android:textSize="20dp" />
    </LinearLayout>

What is the difference between the remap, noremap, nnoremap and vnoremap mapping commands in Vim?

I think the Vim documentation should've explained the meaning behind the naming of these commands. Just telling you what they do doesn't help you remember the names.

map is the "root" of all recursive mapping commands. The root form applies to "normal", "visual+select", and "operator-pending" modes. (I'm using the term "root" as in linguistics.)

noremap is the "root" of all non-recursive mapping commands. The root form applies to the same modes as map. (Think of the nore prefix to mean "non-recursive".)

(Note that there are also the ! modes like map! that apply to insert & command-line.)

See below for what "recursive" means in this context.

Prepending a mode letter like n modify the modes the mapping works in. It can choose a subset of the list of applicable modes (e.g. only "visual"), or choose other modes that map wouldn't apply to (e.g. "insert").

Use help map-modes will show you a few tables that explain how to control which modes the mapping applies to.

Mode letters:

  • n: normal only
  • v: visual and select
  • o: operator-pending
  • x: visual only
  • s: select only
  • i: insert
  • c: command-line
  • l: insert, command-line, regexp-search (and others. Collectively called "Lang-Arg" pseudo-mode)

"Recursive" means that the mapping is expanded to a result, then the result is expanded to another result, and so on.

The expansion stops when one of these is true:

  1. the result is no longer mapped to anything else.
  2. a non-recursive mapping has been applied (i.e. the "noremap" [or one of its ilk] is the final expansion).

At that point, Vim's default "meaning" of the final result is applied/executed.

"Non-recursive" means the mapping is only expanded once, and that result is applied/executed.

Example:

 nmap K H
 nnoremap H G
 nnoremap G gg

The above causes K to expand to H, then H to expand to G and stop. It stops because of the nnoremap, which expands and stops immediately. The meaning of G will be executed (i.e. "jump to last line"). At most one non-recursive mapping will ever be applied in an expansion chain (it would be the last expansion to happen).

The mapping of G to gg only applies if you press G, but not if you press K. This mapping doesn't affect pressing K regardless of whether G was mapped recursively or not, since it's line 2 that causes the expansion of K to stop, so line 3 wouldn't be used.

Call An Asynchronous Javascript Function Synchronously

One thing people might not consider: If you control the async function (which other pieces of code depend on), AND the codepath it would take is not necessarily asynchronous, you can make it synchronous (without breaking those other pieces of code) by creating an optional parameter.

Currently:

async function myFunc(args_etcetc) {
    // you wrote this
    return 'stuff';
}

(async function main() {
    var result = await myFunc('argsetcetc');
    console.log('async result:' result);
})()

Consider:

function myFunc(args_etcetc, opts={}) {
    /*
        param opts :: {sync:Boolean} -- whether to return a Promise or not
    */
    var {sync=false} = opts;
    if (sync===true)
        return 'stuff';
    else
        return new Promise((RETURN,REJECT)=> {
            RETURN('stuff');
        });
}


// async code still works just like before:
(async function main() {
    var result = await myFunc('argsetcetc');
    console.log('async result:', result);
})();
// prints: 'stuff'

// new sync code works, if you specify sync mode:
(function main() {
    var result = myFunc('argsetcetc', {sync:true});
    console.log('sync result:', result);
})();
// prints: 'stuff'

Of course this doesn't work if the async function relies on inherently async operations (network requests, etc.), in which case the endeavor is futile (without effectively waiting idle-spinning for no reason).

Also this is fairly ugly to return either a value or a Promise depending on the options passed in.

("Why would I have written an async function if it didn't use async constructs?" one might ask? Perhaps some modalities/parameters of the function require asynchronicity and others don't, and due to code duplication you wanted a monolithic block rather than separate modular chunks of code in different functions... For example perhaps the argument is either localDatabase (which doesn't require await) or remoteDatabase (which does). Then you could runtime error if you try to do {sync:true} on the remote database. Perhaps this scenario is indicative of another problem, but there you go.)

jQuery Call to WebService returns "No Transport" error

None of the proposed answers completely worked for me. My use case is slightly different (doing an ajax get to an S3 .json file in IE9). Setting jQuery.support.cors = true; got rid of the No Transport error but I was still getting Permission denied errors.

What did work for me was to use the jQuery-ajaxTransport-XDomainRequest to force IE9 to use XDomainRequest. Using this did not require setting jQuery.support.cors = true;

.crx file install in chrome

File format
This tool parses .CRX version 2 format documented by Google. In general, .CRX file format consist of few parts:

Magic header
Version of file format
Public Key information and a package signature Zipped contents of the extension source code Magic header is a signature of the file telling that this file is Chrome Extension. Using this header the operating system can determine the actual type of the file (MIME type is application/x-chrome-extension), and how should it be treaten (is it executable? is it a text file?). Then the window system can show beautiful icon to the user.

In .CRX files the magic header has a constant value Cr24 or 0x43723234.

The version is provided by vendor. The version bytes are 0x02000000.

The next part of the file contains the length of the public key information and the length of a digital signature.

All .CRX packages distributed via Chrome WebStore should have public key information and digital signature in order to make possible for browser to check that the package has been transmitted without modifications and that no additions or replacements were made.

After all of the header stuff, typically ending up on 307'th byte, comes the code of extension, stored as zip-archive. So the remainder of the .crx file is the well-known .zip archive.

.crx file opened in the hex editor called HexFiend (on Mac) The header part of a .crx file selected on the picture above. Obviously, you can extract the remaining .zip archive "by hand" using any simple hex editor. In this example, we use handy HexFiend editor on Mac.

The CRX Extractor loads a file provided, checks a magic header, version and trims the file, so only .zip archive remains. Then it returns obtained .zip archive to user.

ref:
https://crxextractor.com/about.html

https://github.com/vladignatyev/crx-extractor

ALTER table - adding AUTOINCREMENT in MySQL

ALTER TABLE tblcatalog
    CHANGE COLUMN id id INT(11) NOT NULL AUTO_INCREMENT FIRST;

Windows shell command to get the full path to the current directory?

@echo off
for /f "usebackq tokens=*" %%x in (`chdir`) do set var=%%x
echo The currenct directory is: %var%

But, of course, gmaran23's answer is the much easier one.

Binding arrow keys in JS/jQuery

You can use jQuery bind:

$(window).bind('keydown', function(e){
    if (e.keyCode == 37) {
        console.log('left');
    } else if (e.keyCode == 38) {
        console.log('up');
    } else if (e.keyCode == 39) {
        console.log('right');
    } else if (e.keyCode == 40) {
        console.log('down');
    }
});

Ignore Typescript Errors "property does not exist on value of type"

I know the question is already closed but I've found it searching for same TypeScriptException, maybe some one else hit this question searching for this problem.

The problem lays in missing TypeScript typing:

var coordinates = outerElement[0].getBBox();

Throws The property 'getBBox' does not exist on value of type 'HTMLElement'.


The easiest way is to explicitly type variable as `any`
var outerHtmlElement: any = outerElement[0];
var coordinates = outerHtmlElement.getBBox();

Edit, late 2016

Since TypeScript 1.6, the prefered casting operator is as, so those lines can be squashed into:

let coordinates = (outerElement[0] as any).getBBox();


Other solutions

Of course if you'd like to do it right, which is an overkill sometimes, you can:

  1. Create own interface which simply extends HTMLElement
  2. Introduce own typing which extends HTMLElement

Checkbox Check Event Listener

If you have a checkbox in your html something like:

<input id="conducted" type = "checkbox" name="party" value="0">

and you want to add an EventListener to this checkbox using javascript, in your associated js file, you can do as follows:

checkbox = document.getElementById('conducted');

checkbox.addEventListener('change', e => {

    if(e.target.checked){
        //do something
    }

});

Why is there no multiple inheritance in Java, but implementing multiple interfaces is allowed?

Because interfaces specify only what the class is doing, not how it is doing it.

The problem with multiple inheritance is that two classes may define different ways of doing the same thing, and the subclass can't choose which one to pick.

What's wrong with foreign keys?

I echo the answer by Dmitriy - very well put.

For those who are worried about the performance overhead FK's often bring, there's a way (in Oracle) you can get the query optimiser advantage of the FK constraint without the cost overhead of constraint validation during insert, delete or update. That is to create the FK constraint with the attributes RELY DISABLE NOVALIDATE. This means the query optimiser ASSUMES that the constraint has been enforced when building queries, without the database actually enforcing the constraint. You have to be very careful here to take the responsibility when you populate a table with an FK constraint like this to make absolutely sure you don't have data in your FK column(s) that violate the constraint, as if you do so you could get unreliable results from queries that involve the table this FK constraint is on.

I usually use this strategy on some tables in my data mart schema, but not in my integrated staging schema. I make sure the tables I am copying data from already have the same constraint enforced, or the ETL routine enforces the constraint.

Drop unused factor levels in a subsetted data frame

Unfortunately factor() doesn't seem to work when using rxDataStep of RevoScaleR. I do it in two steps: 1) Convert to character and store in temporary external data frame (.xdf). 2) Convert back to factor and store in definitive external data frame. This eliminates any unused factor levels, without loading all the data into memory.

# Step 1) Converts to character, in temporary xdf file:
rxDataStep(inData = "input.xdf", outFile = "temp.xdf", transforms = list(VAR_X = as.character(VAR_X)), overwrite = T)
# Step 2) Converts back to factor:
rxDataStep(inData = "temp.xdf", outFile = "output.xdf", transforms = list(VAR_X = as.factor(VAR_X)), overwrite = T)

How to execute VBA Access module?

You're not running a module -- you're running subroutines/functions that happen to be stored in modules.

If you put the code in a standalone module and don't specify scope in the definitions of your subroutines/functions, they will be public by default, and callable from anywhere within your application. This means that you can call them with RunCode in a macro, from the class modules of forms/reports, from standalone class modules, or for the functions, from SQL (with some caveats).

Given that you were trying to implement in VBA something that you felt was too complicated for SQL, SQL is the likely context in which you want to execute the code. So, you should just be able to call your function within the SQL statement:

  SELECT MyTable.PersonID, MyTable.FirstName, MyTable.LastName, FormatAddress([Address], [City], [State], [Zip], [Country]) As Address
  FROM MyTable;

That SQL calls a public function called FormatAddress() that takes as arguments the components of an address and formats them appropriately. It's a trivial example as you likely would not need a VBA function for that purpose, but the point is that this is how you call functions from within a SQL statement.

Subroutines (i.e., code that returns no value) are not callable from within SQL statements.

How to count the number of columns in a table using SQL?

select count(*) 
from user_tab_columns
where table_name='MYTABLE' --use upper case

Instead of uppercase you can use lower function. Ex: select count(*) from user_tab_columns where lower(table_name)='table_name';

How to set a cell to NaN in a pandas dataframe

As of pandas 1.0.0, you no longer need to use numpy to create null values in your dataframe. Instead you can just use pandas.NA (which is of type pandas._libs.missing.NAType), so it will be treated as null within the dataframe but will not be null outside dataframe context.

Add common prefix to all cells in Excel

Select the cell you want,

Go To Format Cells (or CTRL+1),

Select the "custom" Tab, enter your required format like : "X"#

use a space if needed.

for example, I needed to insert the word "Hours" beside my numbers and used this format : # "hours"

SQL Server query - Selecting COUNT(*) with DISTINCT

You have to create a derived table for the distinct columns and then query the count from that table:

SELECT COUNT(*) 
FROM (SELECT DISTINCT column1,column2
      FROM  tablename  
      WHERE condition ) as dt

Here dt is a derived table.

Rounded table corners CSS only

For a bordered and scrollable table, use this (replace variables, $ starting texts)

If you use thead, tfoot or th, just replace tr:first-child and tr-last-child and td with them.

#table-wrap {
  border: $border solid $color-border;
  border-radius: $border-radius;
}
table {
  border-collapse: collapse;
  border-spacing: 0;
}
table td { border: $border solid $color-border; }
table td:first-child { border-left: none; }
table td:last-child { border-right: none; }
table tr:first-child td { border-top: none; }
table tr:last-child td { border-bottom: none; }
table tr:first-child td:first-child { border-top-left-radius: $border-radius; }
table tr:first-child td:last-child { border-top-right-radius: $border-radius; }
table tr:last-child td:first-child { border-bottom-left-radius: $border-radius; }
table tr:last-child td:last-child { border-bottom-right-radius: $border-radius; }

HTML:

<div id=table-wrap>
  <table>
    <tr>
       <td>1</td>
       <td>2</td>
    </tr>
    <tr>
       <td>3</td>
       <td>4</td>
    </tr>
  </table>
</div>

Is string in array?

Is the array sorted? If so you could do a binary search. Here is the .NET implementation as well. If the array is sorted then a binary search will improve performance over any iterative solution.

Scroll to the top of the page using JavaScript?

Simply use this script for scroll to top direct.

<script>
$(document).ready(function(){
    $("button").click(function(){
        ($('body').scrollTop(0));
    });
});
</script>

How to import data from one sheet to another

Saw this thread while looking for something else and I know it is super old, but I wanted to add my 2 cents.

NEVER USE VLOOKUP. It's one of the worst performing formulas in excel. Use index match instead. It even works without sorting data, unless you have a -1 or 1 in the end of the match formula (explained more below)

Here is a link with the appropriate formulas.

The Sheet 2 formula would be this: =IF(A2="","",INDEX(Sheet1!B:B,MATCH($A2,Sheet1!$A:$A,0)))

  • IF(A2="","", means if A2 is blank, return a blank value
  • INDEX(Sheet1!B:B, is saying INDEX B:B where B:B is the data you want to return. IE the name column.
  • Match(A2, is saying to Match A2 which is the ID you want to return the Name for.
  • Sheet1!A:A, is saying you want to match A2 to the ID column in the previous sheet
  • ,0)) is specifying you want an exact value. 0 means return an exact match to A2, -1 means return smallest value greater than or equal to A2, 1 means return the largest value that is less than or equal to A2. Keep in mind -1 and 1 have to be sorted.

More information on the Index/Match formula

Other fun facts: $ means absolute in a formula. So if you specify $B$1 when filling a formula down or over keeps that same value. If you over $B1, the B remains the same across the formula, but if you fill down, the 1 increases with the row count. Likewise, if you used B$1, filling to the right will increment the B, but keep the reference of row 1.

I also included the use of indirect in the second section. What indirect does is allow you to use the text of another cell in a formula. Since I created a named range sheet1!A:A = ID, sheet1!B:B = Name, and sheet1!C:C=Price, I can use the column name to have the exact same formula, but it uses the column heading to change the search criteria.

Good luck! Hope this helps.

How to create a HTML Cancel button that redirects to a URL

<input class="button" type="button" onclick="window.location.replace('your_url')" value="Cancel" />

Python 3: UnboundLocalError: local variable referenced before assignment

Why not simply return your calculated value and let the caller modify the global variable. It's not a good idea to manipulate a global variable within a function, as below:

Var1 = 1
Var2 = 0

def function(): 
    if Var2 == 0 and Var1 > 0:
        print("Result One")
    elif Var2 == 1 and Var1 > 0:
        print("Result Two")
    elif Var1 < 1:
        print("Result Three")
    return Var1 - 1

Var1 = function()

or even make local copies of the global variables and work with them and return the results which the caller can then assign appropriately

def function():
v1, v2 = Var1, Var2
# calculate using the local variables v1 & v2
return v1 - 1

Var1 = function()

jQuery get the rendered height of an element?

Have you set the height in the css specifically? If you haven't you need to use offsetHeight; rather than height

var h = document.getElementById('someDiv').style.offsetHeight;

Press enter in textbox to and execute button command

    private void textbox1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Enter)
        {
            //cod for run
        }
    }

    private void buttonSearch_Click(object sender, EventArgs e)
    {
        textbox1_KeyDown(sender, new KeyEventArgs(Keys.Enter));
    }

How to get full REST request body using Jersey?

Since you're transferring data in xml, you could also (un)marshal directly from/to pojos.

There's an example (and more info) in the jersey user guide, which I copy here:

POJO with JAXB annotations:

@XmlRootElement
public class Planet {
    public int id;
    public String name;
    public double radius;
}

Resource:

@Path("planet")
public class Resource {

    @GET
    @Produces(MediaType.APPLICATION_XML)
    public Planet getPlanet() {
        Planet p = new Planet();
        p.id = 1;
        p.name = "Earth";
        p.radius = 1.0;

        return p;
    }

    @POST
    @Consumes(MediaType.APPLICATION_XML)
    public void setPlanet(Planet p) {
        System.out.println("setPlanet " + p.name);
    }

}      

The xml that gets produced/consumed:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<planet>
    <id>1</id>
    <name>Earth</name>
    <radius>1.0</radius>
</planet>

Can a relative sitemap url be used in a robots.txt?

Google crawlers are not smart enough, they can't crawl relative URLs, that's why it's always recommended to use absolute URL's for better crawlability and indexability.

Therefore, you can not use this variation

> sitemap: /sitemap.xml

Recommended syntax is

Sitemap: https://www.yourdomain.com/sitemap.xml

Note:

  • Don't forgot to capitalise the first letter in "sitemap"
  • Don't forgot to put space after "Sitemap:"

Split string into string array of single characters

string input = "this is a test";
string[] afterSplit = input.Split();

foreach (var word in afterSplit)
    Console.WriteLine(word);

Result:

this
is
a
test

Moving Average Pandas

The rolling mean returns a Series you only have to add it as a new column of your DataFrame (MA) as described below.

For information, the rolling_mean function has been deprecated in pandas newer versions. I have used the new method in my example, see below a quote from the pandas documentation.

Warning Prior to version 0.18.0, pd.rolling_*, pd.expanding_*, and pd.ewm* were module level functions and are now deprecated. These are replaced by using the Rolling, Expanding and EWM. objects and a corresponding method call.

df['MA'] = df.rolling(window=5).mean()

print(df)
#             Value    MA
# Date                   
# 1989-01-02   6.11   NaN
# 1989-01-03   6.08   NaN
# 1989-01-04   6.11   NaN
# 1989-01-05   6.15   NaN
# 1989-01-09   6.25  6.14
# 1989-01-10   6.24  6.17
# 1989-01-11   6.26  6.20
# 1989-01-12   6.23  6.23
# 1989-01-13   6.28  6.25
# 1989-01-16   6.31  6.27

Granting DBA privileges to user in Oracle

You need only to write:

GRANT DBA TO NewDBA;

Because this already makes the user a DB Administrator

How to redirect Valgrind's output to a file?

You can also set the options --log-fd if you just want to read your logs with a less. For example :

valgrind --log-fd=1 ls | less

Using Page_Load and Page_PreRender in ASP.Net

Well a big requirement to implement PreRender as opposed to Load is the need to work with the controls on the page. On Page_Load, the controls are not rendered, and therefore cannot be referenced.

Dynamically add item to jQuery Select2 control that uses AJAX

This is a lot easier to do starting in select2 v4. You can create a new Option, and append it to the select element directly. See my codepen or the example below:

_x000D_
_x000D_
$(document).ready(function() {_x000D_
    $("#state").select2({_x000D_
      tags: true_x000D_
    });_x000D_
      _x000D_
    $("#btn-add-state").on("click", function(){_x000D_
      var newStateVal = $("#new-state").val();_x000D_
      // Set the value, creating a new option if necessary_x000D_
      if ($("#state").find("option[value=" + newStateVal + "]").length) {_x000D_
        $("#state").val(newStateVal).trigger("change");_x000D_
      } else { _x000D_
        // Create the DOM option that is pre-selected by default_x000D_
        var newState = new Option(newStateVal, newStateVal, true, true);_x000D_
        // Append it to the select_x000D_
        $("#state").append(newState).trigger('change');_x000D_
      } _x000D_
    });  _x000D_
});
_x000D_
<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.1/css/select2.min.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.6/js/bootstrap.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.1/js/select2.min.js"></script>_x000D_
_x000D_
_x000D_
<select id="state" class="js-example-basic-single" type="text" style="width:90%">_x000D_
  <option value="AL">Alabama</option>_x000D_
  <option value="WY">Wyoming</option>_x000D_
</select>_x000D_
<br>_x000D_
<br>_x000D_
<input id="new-state" type="text" />_x000D_
<button type="button" id="btn-add-state">Set state value</button>
_x000D_
_x000D_
_x000D_

Hint: try entering existing values into the text box, like "AL" or "WY". Then try adding some new values.

What’s the best RESTful method to return total number of items in an object?

I have been doing some extensive research into this and other REST paging related questions lately and thought it constructive to add some of my findings here. I'm expanding the question a bit to include thoughts on paging as well as the count as they are intimitely related.

Headers

The paging metadata is included in the response in the form of response headers. The big benefit of this approach is that the response payload itself is just the actual data requestor was asking for. Making processing the response easier for clients that are not interested in the paging information.

There are a bunch of (standard and custom) headers used in the wild to return paging related information, including the total count.

X-Total-Count

X-Total-Count: 234

This is used in some APIs I found in the wild. There are also NPM packages for adding support for this header to e.g. Loopback. Some articles recommend setting this header as well.

It is often used in combination with the Link header, which is a pretty good solution for paging, but lacks the total count information.

Link

Link: </TheBook/chapter2>;
      rel="previous"; title*=UTF-8'de'letztes%20Kapitel,
      </TheBook/chapter4>;
      rel="next"; title*=UTF-8'de'n%c3%a4chstes%20Kapitel

I feel, from reading a lot on this subject, that the general consensus is to use the Link header to provide paging links to clients using rel=next, rel=previous etc. The problem with this is that it lacks the information of how many total records there are, which is why many APIs combine this with the X-Total-Count header.

Alternatively, some APIs and e.g. the JsonApi standard, use the Link format, but add the information in a response envelope instead of to a header. This simplifies access to the metadata (and creates a place to add the total count information) at the expense of increasing complexity of accessing the actual data itself (by adding an envelope).

Content-Range

Content-Range: items 0-49/234

Promoted by a blog article named Range header, I choose you (for pagination)!. The author makes a strong case for using the Range and Content-Range headers for pagination. When we carefully read the RFC on these headers, we find that extending their meaning beyond ranges of bytes was actually anticipated by the RFC and is explicitly permitted. When used in the context of items instead of bytes, the Range header actually gives us a way to both request a certain range of items and indicate what range of the total result the response items relate to. This header also gives a great way to show the total count. And it is a true standard that mostly maps one-to-one to paging. It is also used in the wild.

Envelope

Many APIs, including the one from our favorite Q&A website use an envelope, a wrapper around the data that is used to add meta information about the data. Also, OData and JsonApi standards both use a response envelope.

The big downside to this (imho) is that processing the response data becomes more complex as the actual data has to be found somewhere in the envelope. Also there are many different formats for that envelope and you have to use the right one. It is telling that the response envelopes from OData and JsonApi are wildly different, with OData mixing in metadata at multiple points in the response.

Separate endpoint

I think this has been covered enough in the other answers. I did not investigate this much because I agree with the comments that this is confusing as you now have multiple types of endpoints. I think it's nicest if every endpoint represents a (collection of) resource(s).

Further thoughts

We don't only have to communicate the paging meta information related to the response, but also allow the client to request specific pages/ranges. It is interesting to also look at this aspect to end up with a coherent solution. Here too we can use headers (the Range header seems very suitable), or other mechanisms such as query parameters. Some people advocate treating pages of results as separate resources, which may make sense in some use cases (e.g. /books/231/pages/52. I ended up selecting a wild range of frequently used request parameters such as pagesize, page[size] and limit etc in addition to supporting the Range header (and as request parameter as well).

Android Min SDK Version vs. Target SDK Version

android:minSdkVersion

An integer designating the minimum API Level required for the application to run. The Android system will prevent the user from installing the application if the system's API Level is lower than the value specified in this attribute. You should always declare this attribute.

android:targetSdkVersion

An integer designating the API Level that the application is targetting.

With this attribute set, the application says that it is able to run on older versions (down to minSdkVersion), but was explicitly tested to work with the version specified here. Specifying this target version allows the platform to disable compatibility settings that are not required for the target version (which may otherwise be turned on in order to maintain forward-compatibility) or enable newer features that are not available to older applications. This does not mean that you can program different features for different versions of the platform—it simply informs the platform that you have tested against the target version and the platform should not perform any extra work to maintain forward-compatibility with the target version.

For more information refer this URL:

http://developer.android.com/guide/topics/manifest/uses-sdk-element.html

Ball to Ball Collision - Detection and Handling

You have two easy ways to do this. Jay has covered the accurate way of checking from the center of the ball.

The easier way is to use a rectangle bounding box, set the size of your box to be 80% the size of the ball, and you'll simulate collision pretty well.

Add a method to your ball class:

public Rectangle getBoundingRect()
{
   int ballHeight = (int)Ball.Height * 0.80f;
   int ballWidth = (int)Ball.Width * 0.80f;
   int x = Ball.X - ballWidth / 2;
   int y = Ball.Y - ballHeight / 2;

   return new Rectangle(x,y,ballHeight,ballWidth);
}

Then, in your loop:

// Checks every ball against every other ball. 
// For best results, split it into quadrants like Ryan suggested. 
// I didn't do that for simplicity here.
for (int i = 0; i < balls.count; i++)
{
    Rectangle r1 = balls[i].getBoundingRect();

    for (int k = 0; k < balls.count; k++)
    {

        if (balls[i] != balls[k])
        {
            Rectangle r2 = balls[k].getBoundingRect();

            if (r1.Intersects(r2))
            {
                 // balls[i] collided with balls[k]
            }
        }
    }
}

How to save and load cookies using Python + Selenium WebDriver

Remember, you can only add a cookie for the current domain.

If you want to add a cookie for your Google account, do

browser.get('http://google.com')
for cookie in cookies:
    browser.add_cookie(cookie)

What is the difference between synchronous and asynchronous programming (in node.js)

Sync Programming

Programming languages like C, C#, Java are sync programming, what so ever you write will be execute in order of your writing.

-GET DATA FROM SQL.
//Suppose fetching data take 500 msec

-PERFORM SOME OTHER FUNCTION.
//Performing some function other will take 100 msec, but execution of other 
//task start only when fetching of sql data done (i.e some other function 
//can execute only after first in process job finishes).

-TOTAL TIME OF EXECUTION IS ALWAYS GREATER THAN (500 + 100 + processing time) 
msec

Async

NodeJs comes up with async feature, it's non-blocking in nature, suppose in any I/O task which is taking time (fetching, writing, reading), nodejs won't kept idle and wait for the task to be finish, it'll start executing next tasks in the queue, and whenever that time taking task completed it will notify using callback. Following example will help:

//Nodejs uses callback pattern to describe functions.
//Please read callback pattern to understand this example

//Suppose following function (I/O involved) took 500 msec
function timeConsumingFunction(params, callback){
  //GET DATA FROM SQL
  getDataFromSql(params, function(error, results){
    if(error){
      callback(error);
    }
    else{
      callback(null, results);
    }
  })
}

//Suppose following function is non-blocking and took 100 msec
function someOtherTask(){
  //some other task
  console.log('Some Task 1');
  console.log('Some Task 2');
}

console.log('Execution Start');

//Start With this function
timeConsumingFunction(params, function(error, results){
    if(error){
      console.log('Error')
    }
    else{
      console.log('Successfull'); 
    }
  })

//As (suppose) timeConsumingFunction took 500 msec, 
//As NodeJs is non-blocking, rather than remain idle for 500 msec, it will start 
//execute following function immediately
someOtherTask();

In Short, Output is as:

Execution Start
//Roughly after 105 msec (5 msec it'll take in processing)
Some Task 1
Some Task 2
//Roughly After 510 msec
Error/Successful //depends on success and failure of DB function execution

Difference is clear where sync will definitely take more than 600 (500 + 100 + processing time) msec, async saves time.

How do I handle too long index names in a Ruby on Rails ActiveRecord migration?

You can also do

t.index([:branch_id, :party_id], unique: true, name: 'by_branch_party')

as in the Ruby on Rails API.

How to display text in pygame?

This is slighly more OS independent way:

# do this init somewhere
import pygame
pygame.init()
screen = pygame.display.set_mode((640, 480))
font = pygame.font.Font(pygame.font.get_default_font(), 36)

# now print the text
text_surface = font.render('Hello world', antialias=True, color=(0, 0, 0))
screen.blit(text_surface, dest=(0,0))

Click a button programmatically

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Button2_Click(Sender, e)
End Sub

This Code call button click event programmatically

Checking version of angular-cli that's installed?

Execute:

ng v

or

ng --version

tell you the current angular cli version number

enter image description here

regular expression for finding 'href' value of a <a> link

I'd recommend using an HTML parser over a regex, but still here's a regex that will create a capturing group over the value of the href attribute of each links. It will match whether double or single quotes are used.

<a\s+(?:[^>]*?\s+)?href=(["'])(.*?)\1

You can view a full explanation of this regex at here.

Snippet playground:

_x000D_
_x000D_
const linkRx = /<a\s+(?:[^>]*?\s+)?href=(["'])(.*?)\1/;_x000D_
const textToMatchInput = document.querySelector('[name=textToMatch]');_x000D_
_x000D_
document.querySelector('button').addEventListener('click', () => {_x000D_
  console.log(textToMatchInput.value.match(linkRx));_x000D_
});
_x000D_
<label>_x000D_
  Text to match:_x000D_
  <input type="text" name="textToMatch" value='<a href="google.com"'>_x000D_
  _x000D_
  <button>Match</button>_x000D_
 </label>
_x000D_
_x000D_
_x000D_

What are Aggregates and PODs and how/why are they special?

POD in C++11 was basically split into two different axes here: triviality and layout. Triviality is about the relationship between an object's conceptual value and the bits of data within its storage. Layout is about... well, the layout of an object's subobjects. Only class types have layout, while all types have triviality relationships.

So here is what the triviality axis is about:

  1. Non-trivially copyable: The value of objects of such types may be more than just the binary data that are stored directly within the object.

    For example, unique_ptr<T> stores a T*; that is the totality of the binary data within the object. But that's not the totality of the value of a unique_ptr<T>. A unique_ptr<T> stores either a nullptr or a pointer to an object whose lifetime is managed by the unique_ptr<T> instance. That management is part of the value of a unique_ptr<T>. And that value is not part of the binary data of the object; it is created by the various member functions of that object.

    For example, to assign nullptr to a unique_ptr<T> is to do more than just change the bits stored in the object. Such an assignment must destroy any object managed by the unique_ptr. To manipulate the internal storage of a unique_ptr without going through its member functions would damage this mechanism, to change its internal T* without destroying the object it currently manages, would violate the conceptual value that the object possesses.

  2. Trivially copyable: The value of such objects are exactly and only the contents of their binary storage. This is what makes it reasonable to allow copying that binary storage to be equivalent to copying the object itself.

    The specific rules that define trivial copyability (trivial destructor, trivial/deleted copy/move constructors/assignment) are what is required for a type to be binary-value-only. An object's destructor can participate in defining the "value" of an object, as in the case with unique_ptr. If that destructor is trivial, then it doesn't participate in defining the object's value.

    Specialized copy/move operations also can participate in an object's value. unique_ptr's move constructor modifies the source of the move operation by null-ing it out. This is what ensures that the value of a unique_ptr is unique. Trivial copy/move operations mean that such object value shenanigans are not being played, so the object's value can only be the binary data it stores.

  3. Trivial: This object is considered to have a functional value for any bits that it stores. Trivially copyable defines the meaning of the data store of an object as being just that data. But such types can still control how data gets there (to some extent). Such a type can have default member initializers and/or a default constructor that ensures that a particular member always has a particular value. And thus, the conceptual value of the object can be restricted to a subset of the binary data that it could store.

    Performing default initialization on a type that has a trivial default constructor will leave that object with completely uninitialized values. As such, a type with a trivial default constructor is logically valid with any binary data in its data storage.

The layout axis is really quite simple. Compilers are given a lot of leeway in deciding how the subobjects of a class are stored within the class's storage. However, there are some cases where this leeway is not necessary, and having more rigid ordering guarantees is useful.

Such types are standard layout types. And the C++ standard doesn't even really do much with saying what that layout is specifically. It basically says three things about standard layout types:

  1. The first subobject is at the same address as the object itself.

  2. You can use offsetof to get a byte offset from the outer object to one of its member subobjects.

  3. unions get to play some games with accessing subobjects through an inactive member of a union if the active member is (at least partially) using the same layout as the inactive one being accessed.

Compilers generally permit standard layout objects to map to struct types with the same members in C. But there is no statement of that in the C++ standard; that's just what compilers feel like doing.

POD is basically a useless term at this point. It is just the intersection of trivial copyability (the value is only its binary data) and standard layout (the order of its subobjects is more well-defined). One can infer from such things that the type is C-like and could map to similar C objects. But the standard has no statements to that effect.


can you please elaborate following rules:

I'll try:

a) standard-layout classes must have all non-static data members with the same access control

That's simple: all non-static data members must all be public, private, or protected. You can't have some public and some private.

The reasoning for them goes to the reasoning for having a distinction between "standard layout" and "not standard layout" at all. Namely, to give the compiler the freedom to choose how to put things into memory. It's not just about vtable pointers.

Back when they standardized C++ in 98, they had to basically predict how people would implement it. While they had quite a bit of implementation experience with various flavors of C++, they weren't certain about things. So they decided to be cautious: give the compilers as much freedom as possible.

That's why the definition of POD in C++98 is so strict. It gave C++ compilers great latitude on member layout for most classes. Basically, POD types were intended to be special cases, something you specifically wrote for a reason.

When C++11 was being worked on, they had a lot more experience with compilers. And they realized that... C++ compiler writers are really lazy. They had all this freedom, but they didn't do anything with it.

The rules of standard layout are more or less codifying common practice: most compilers didn't really have to change much if anything at all to implement them (outside of maybe some stuff for the corresponding type traits).

Now, when it came to public/private, things are different. The freedom to reorder which members are public vs. private actually can matter to the compiler, particularly in debugging builds. And since the point of standard layout is that there is compatibility with other languages, you can't have the layout be different in debug vs. release.

Then there's the fact that it doesn't really hurt the user. If you're making an encapsulated class, odds are good that all of your data members will be private anyway. You generally don't expose public data members on fully encapsulated types. So this would only be a problem for those few users who do want to do that, who want that division.

So it's no big loss.

b) only one class in the whole inheritance tree can have non-static data members,

The reason for this one comes back to why they standardized standard layout again: common practice.

There's no common practice when it comes to having two members of an inheritance tree that actually store things. Some put the base class before the derived, others do it the other way. Which way do you order the members if they come from two base classes? And so on. Compilers diverge greatly on these questions.

Also, thanks to the zero/one/infinity rule, once you say you can have two classes with members, you can say as many as you want. This requires adding a lot of layout rules for how to handle this. You have to say how multiple inheritance works, which classes put their data before other classes, etc. That's a lot of rules, for very little material gain.

You can't make everything that doesn't have virtual functions and a default constructor standard layout.

and the first non-static data member cannot be of a base class type (this could break aliasing rules).

I can't really speak to this one. I'm not educated enough in C++'s aliasing rules to really understand it. But it has something to do with the fact that the base member will share the same address as the base class itself. That is:

struct Base {};
struct Derived : Base { Base b; };

Derived d;
static_cast<Base*>(&d) == &d.b;

And that's probably against C++'s aliasing rules. In some way.

However, consider this: how useful could having the ability to do this ever actually be? Since only one class can have non-static data members, then Derived must be that class (since it has a Base as a member). So Base must be empty (of data). And if Base is empty, as well as a base class... why have a data member of it at all?

Since Base is empty, it has no state. So any non-static member functions will do what they do based on their parameters, not their this pointer.

So again: no big loss.

How do I get column names to print in this C# program?

You need to loop over loadDT.Columns, like this:

foreach (DataColumn column in loadDT.Columns)
{
    Console.Write("Item: ");
    Console.Write(column.ColumnName);
    Console.Write(" ");
    Console.WriteLine(row[column]);
}

error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' -- Missing /var/run/mysqld/mysqld.sock

My solution;

Ubuntu 18.04 (WSL)

/etc/mysql/my.cnf

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

/etc/mysql/mysql.conf.d/mysqld.cnf

[mysqld]
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306

I changed the port. It's worked for me. You can write another port. Example 3355

C++ Pass A String

You should be able to call print("yo!") since there is a constructor for std::string which takes a const char*. These single argument constructors define implicit conversions from their aguments to their class type (unless the constructor is declared explicit which is not the case for std::string). Have you actually tried to compile this code?

void print(std::string input)
{
    cout << input << endl;
} 
int main()
{
    print("yo");
}

It compiles fine for me in GCC. However, if you declared print like this void print(std::string& input) then it would fail to compile since you can't bind a non-const reference to a temporary (the string would be a temporary constructed from "yo")

ImportError in importing from sklearn: cannot import name check_build

I had the same issue on Windows. Solved it by installing Numpy+MKL from http://www.lfd.uci.edu/~gohlke/pythonlibs/#numpy (there it's recommended to install numpy+mkl before other packages that depend on it) as suggested by this answer.

Using Colormaps to set color of line in matplotlib

U may do as I have written from my deleted account (ban for new posts :( there was). Its rather simple and nice looking.

Im using 3-rd one of these 3 ones usually, also I wasny checking 1 and 2 version.

from matplotlib.pyplot import cm
import numpy as np

#variable n should be number of curves to plot (I skipped this earlier thinking that it is obvious when looking at picture - sorry my bad mistake xD): n=len(array_of_curves_to_plot)
#version 1:

color=cm.rainbow(np.linspace(0,1,n))
for i,c in zip(range(n),color):
   ax1.plot(x, y,c=c)

#or version 2: - faster and better:

color=iter(cm.rainbow(np.linspace(0,1,n)))
c=next(color)
plt.plot(x,y,c=c)

#or version 3:

color=iter(cm.rainbow(np.linspace(0,1,n)))
for i in range(n):
   c=next(color)
   ax1.plot(x, y,c=c)

example of 3:

Ship RAO of Roll vs Ikeda damping in function of Roll amplitude A44

urllib2.HTTPError: HTTP Error 403: Forbidden

By adding a few more headers I was able to get the data:

import urllib2,cookielib

site= "http://www.nseindia.com/live_market/dynaContent/live_watch/get_quote/getHistoricalData.jsp?symbol=JPASSOCIAT&fromDate=1-JAN-2012&toDate=1-AUG-2012&datePeriod=unselected&hiddDwnld=true"
hdr = {'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.64 Safari/537.11',
       'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
       'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.3',
       'Accept-Encoding': 'none',
       'Accept-Language': 'en-US,en;q=0.8',
       'Connection': 'keep-alive'}

req = urllib2.Request(site, headers=hdr)

try:
    page = urllib2.urlopen(req)
except urllib2.HTTPError, e:
    print e.fp.read()

content = page.read()
print content

Actually, it works with just this one additional header:

'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',

Disable Pinch Zoom on Mobile Web

EDIT: Because this keeps getting commented on, we all know that we shouldn't do this. The question was how do I do it, not should I do it.

Add this into your for mobile devices. Then do your widths in percentages and you'll be fine:

<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />

Add this in for devices that can't use viewport too:

<meta name="HandheldFriendly" content="true" />

What is the difference between res.end() and res.send()?

In addition to the excellent answers, I would like to emphasize here when to use res.end() and when to use res.send() this was why I originally landed here and I didn't found a solution.

The answer is really simple

res.end() is used to quickly end the response without sending any data.

An example for this would be starting a process on a server

app.get(/start-service, (req, res) => {
   // Some logic here
   exec('./application'); // dummy code
   res.end();
});

If you would like to send data in your response then you should use res.send() instead

app.get(/start-service, (req, res) => {
   res.send('{"age":22}');
});

Here you can read more

Jinja2 template not rendering if-elif-else statement properly

You are testing if the values of the variables error and Already are present in RepoOutput[RepoName.index(repo)]. If these variables don't exist then an undefined object is used.

Both of your if and elif tests therefore are false; there is no undefined object in the value of RepoOutput[RepoName.index(repo)].

I think you wanted to test if certain strings are in the value instead:

{% if "error" in RepoOutput[RepoName.index(repo)] %}
    <td id="error"> {{ RepoOutput[RepoName.index(repo)] }} </td>
{% elif "Already" in RepoOutput[RepoName.index(repo) %}
    <td id="good"> {{ RepoOutput[RepoName.index(repo)] }} </td>
{% else %}
    <td id="error"> {{ RepoOutput[RepoName.index(repo)] }} </td>
{% endif %}
</tr>

Other corrections I made:

  • Used {% elif ... %} instead of {$ elif ... %}.
  • moved the </tr> tag out of the if conditional structure, it needs to be there always.
  • put quotes around the id attribute

Note that most likely you want to use a class attribute instead here, not an id, the latter must have a value that must be unique across your HTML document.

Personally, I'd set the class value here and reduce the duplication a little:

{% if "Already" in RepoOutput[RepoName.index(repo)] %}
    {% set row_class = "good" %}
{% else %}
    {% set row_class = "error" %}
{% endif %}
<td class="{{ row_class }}"> {{ RepoOutput[RepoName.index(repo)] }} </td>

Android Studio - Auto complete and other features not working

If nothing works (like happened with me ) go to your user profile in windows at %userprofile% . You will find folders there (hidden) named with the version of the android studio you are using and prefixed with a dot.

like .AndroidStudio3.1. Just delete that .

How to set ChartJS Y axis title?

For x and y axes:

     options : {
      scales: {
        yAxes: [{
          scaleLabel: {
            display: true,
            labelString: 'probability'
          }
        }],
        xAxes: [{
          scaleLabel: {
            display: true,
            labelString: 'hola'
          }
        }],
      }
    }

Start HTML5 video at a particular position when loading?

WITHOUT USING JAVASCRIPT

Just add #t=[(start_time), (end_time)] to the end of your media URL. The only setback (if you want to see it that way) is you'll need to know how long your video is to indicate the end time. Example:

<video>
    <source src="splash.mp4#t=10,20" type="video/mp4">
</video>

Notes: Not supported in IE

Insert text with single quotes in PostgreSQL

String literals

Escaping single quotes ' by doubling them up -> '' is the standard way and works of course:

'user's log'     -- incorrect syntax (unbalanced quote)
'user''s log'

In old versions or if you still run with standard_conforming_strings = off or, generally, if you prepend your string with E to declare Posix escape string syntax, you can also escape with the backslash \:

E'user\'s log'

Backslash itself is escaped with another backslash. But that's generally not preferable.
If you have to deal with many single quotes or multiple layers of escaping, you can avoid quoting hell in PostgreSQL with dollar-quoted strings:

'escape '' with '''''
$$escape ' with ''$$

To further avoid confusion among dollar-quotes, add a unique token to each pair:

$token$escape ' with ''$token$

Which can be nested any number of levels:

$token2$Inner string: $token1$escape ' with ''$token1$ is nested$token2$

Pay attention if the $ character should have special meaning in your client software. You may have to escape it in addition. This is not the case with standard PostgreSQL clients like psql or pgAdmin.

That is all very useful for writing plpgsql functions or ad-hoc SQL commands. It cannot alleviate the need to use prepared statements or some other method to safeguard against SQL injection in your application when user input is possible, though. @Craig's answer has more on that. More details:

Values inside Postgres

When dealing with values inside the database, there are a couple of useful functions to quote strings properly:

  • quote_literal() or quote_nullable() - the latter outputs the string NULL for null input. (There is also quote_ident() to double-quote strings where needed to get valid SQL identifiers.)
  • format() with the format specifier %L is equivalent to quote_nullable().
    Like: format('%L', string_var)
  • concat() or concat_ws() are typically no good for this purpose as those do not escape nested single quotes and backslashes.

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

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

select into in mysql

Use the CREATE TABLE SELECT syntax.

http://dev.mysql.com/doc/refman/5.0/en/create-table-select.html

CREATE TABLE new_tbl SELECT * FROM orig_tbl;

How to Check if value exists in a MySQL database

For Exact Match

"SELECT * FROM yourTable WHERE city = 'c7'"

For Pattern / Wildcard Search

"SELECT * FROM yourTable WHERE city LIKE '%c7%'"

Of course you can change '%c7%' to '%c7' or 'c7%' depending on how you want to search it. For exact match, use first query example.

PHP

$result = mysql_query("SELECT * FROM yourTable WHERE city = 'c7'");
$matchFound = mysql_num_rows($result) > 0 ? 'yes' : 'no';
echo $matchFound;

You can also use if condition there.

How to get WordPress post featured image URL

You will try this

<?php $url = wp_get_attachment_url(get_post_thumbnail_id($post->ID), 'full'); ?> // Here you can manage your image size like medium, thumbnail, or custom size
    <img src="<?php echo $url ?>" 
/>

Share data between AngularJS controllers

There are multiple ways to do this.

  1. Events - already explained well.

  2. ui router - explained above.

  3. Service - with update method displayed above
  4. BAD - Watching for changes.
  5. Another parent child approach rather than emit and brodcast -

*

<superhero flight speed strength> Superman is here! </superhero>
<superhero speed> Flash is here! </superhero>

*

app.directive('superhero', function(){
    return {
        restrict: 'E',
        scope:{}, // IMPORTANT - to make the scope isolated else we will pollute it in case of a multiple components.
        controller: function($scope){
            $scope.abilities = [];
            this.addStrength = function(){
                $scope.abilities.push("strength");
            }
            this.addSpeed = function(){
                $scope.abilities.push("speed");
            }
            this.addFlight = function(){
                $scope.abilities.push("flight");
            }
        },
        link: function(scope, element, attrs){
            element.addClass('button');
            element.on('mouseenter', function(){
               console.log(scope.abilities);
            })
        }
    }
});
app.directive('strength', function(){
    return{
        require:'superhero',
        link: function(scope, element, attrs, superHeroCtrl){
            superHeroCtrl.addStrength();
        }
    }
});
app.directive('speed', function(){
    return{
        require:'superhero',
        link: function(scope, element, attrs, superHeroCtrl){
            superHeroCtrl.addSpeed();
        }
    }
});
app.directive('flight', function(){
    return{
        require:'superhero',
        link: function(scope, element, attrs, superHeroCtrl){
            superHeroCtrl.addFlight();
        }
    }
});

How do I determine height and scrolling position of window in jQuery?

$(window).height()

$(window).width()

There is also a plugin to jquery to determine element location and offsets

http://plugins.jquery.com/project/dimensions

scrolling offset = offsetHeight property of an element

Force download a pdf link using javascript/ajax/jquery

With JavaScript it is very difficult if not impossible(?). I would suggest using some sort of code-behind language such as PHP, C#, or Java. If you were to use PHP, you could, in the page your button posts to, do something like this:

<?php
header('Content-type: application/pdf');
header('Content-disposition: attachment; filename=filename.pdf');
readfile("http://manuals.info.apple.com/en/iphone_user_guide.pdf");
?>

This also seems to work for JS (from http://www.phpbuilder.com/board/showthread.php?t=10149735):

<body>
<script>
function downloadme(x){
myTempWindow = window.open(x,'','left=10000,screenX=10000');
myTempWindow.document.execCommand('SaveAs','null','download.pdf');
myTempWindow.close();
}
</script>

<a href=javascript:downloadme('http://manuals.info.apple.com/en/iphone_user_guide.pdf');>Download this pdf</a>
</body>

ImportError: No module named google.protobuf

On Mac OS - Installing tensorflow 1.3 - it will automatically remove other protobuf installs and install protobuf 3.4. However, this does not work and neither does installing or downgrading to any other protobuf version.

However I found a solution. Not sure why this works - but on Mac OS this solved it.

pip install google

Java function for arrays like PHP's join()?

There is simple shorthand technique I use most of the times..

String op = new String;
for (int i : is) 
{
    op += candidatesArr[i-1]+",";
}
op = op.substring(0, op.length()-1);

C Program to find day of week given date

This one works: I took January 2006 as a reference. (It is a Sunday)

int isLeapYear(int year) {

     if(((year%4==0)&&(year%100!=0))||((year%400==0))) 
        return 1;
     else 
        return 0;

 }

int isDateValid(int dd,int mm,int yyyy) {

    int isValid=-1; 
    if(mm<0||mm>12) {
        isValid=-1;
    }
    else {

    if((mm==1)||(mm==3)||(mm==5)||(mm==7)||(mm==8)||(mm==10)||(mm==12)) {
           if((dd>0)&&(dd<=31))
             isValid=1;
    }  else if((mm==4)||(mm==6)||(mm==9)||(mm==11)) {
         if((dd>0)&&(dd<=30))
             isValid=1;
    }  else {
             if(isLeapYear(yyyy)){
                 if((dd>0)&&dd<30)
                     isValid=1;
             } else {
                   if((dd>0)&&dd<29)
                     isValid=1;
             }
        }  



    }
               return isValid;



 }


int calculateDayOfWeek(int dd,int mm,int yyyy)  {

                if(isDateValid(dd,mm,yyyy)==-1) {
                    return -1;
                }

                 int days=0;
                  int i; 

                   for(i=yyyy-1;i>=2006;i--) {
                         days+=(365+isLeapYear(i));

                     }
                     printf("days after years is %d\n",days);

                   for(i=mm-1;i>0;i--) {

                       if((i==1)||(i==3)||(i==5)||(i==7)||(i==8)||(i==10)) {

                           days+=31;
                       }
                       else if((i==4)||(i==6)||(i==9)||(i==11)) {
                           days+=30;
                       } else {

                           days+= (28+isLeapYear(i));

                       }


                   }
                       printf("days after months is %d\n",days);

                   days+=dd;

                   printf("days after days is %d\n",days);

                   return ((days-1)%7);                


              }

Python/Django: log to console under runserver, log to file under Apache

You can configure logging in your settings.py file.

One example:

if DEBUG:
    # will output to your console
    logging.basicConfig(
        level = logging.DEBUG,
        format = '%(asctime)s %(levelname)s %(message)s',
    )
else:
    # will output to logging file
    logging.basicConfig(
        level = logging.DEBUG,
        format = '%(asctime)s %(levelname)s %(message)s',
        filename = '/my_log_file.log',
        filemode = 'a'
    )

However that's dependent upon setting DEBUG, and maybe you don't want to have to worry about how it's set up. See this answer on How can I tell whether my Django application is running on development server or not? for a better way of writing that conditional. Edit: the example above is from a Django 1.1 project, logging configuration in Django has changed somewhat since that version.

Background color not showing in print preview

Your CSS must be like this:

@media print {
   body {
      -webkit-print-color-adjust: exact;
   }
}

.vendorListHeading th {
   background-color: #1a4567 !important;
   color: white !important;   
}

Calculating the difference between two Java date instances

There is an easy way to do this in java

//create an utility method

public long getDaysBetweenDates(Date d1, Date d2){
return TimeUnit.MILLISECONDS.toDays(d1.getTime() - d2.getTime());
}

This method will return the number of days between the 2 dates. Either you can use the default java date format or can easily convert from any date format.

How do I get the object if it exists, or None if it does not exist?

It's one of those annoying functions that you might not want to re-implement:

from annoying.functions import get_object_or_None
#...
user = get_object_or_None(Content, name="baby")

Change the bullet color of list

You have to use image

.listStyle {
    list-style: none;
    background: url(bullet.jpg) no-repeat left center;
    padding-left: 40px;
}

How can I split a JavaScript string by white space or comma?

you can use regex in order to catch any length of white space, and this would be like:

var text = "hoi how     are          you";
var arr = text.split(/\s+/);

console.log(arr) // will result : ["hoi", "how", "are", "you"]

console.log(arr[2]) // will result : "are" 

Make iframe automatically adjust height according to the contents without using scrollbar?

The suggestion by hjpotter92 does not work in safari! I have made a small adjustment to the script so it now works in Safari as well.

Only change made is resetting height to 0 on every load in order to enable some browsers to decrease height.

Add this to <head> tag:

<script type="text/javascript">
  function resizeIframe(obj){
     obj.style.height = 0;
     obj.style.height = obj.contentWindow.document.body.scrollHeight + 'px';
  }
</script>

And add the following onload attribute to your iframe, like so

<iframe onload='resizeIframe(this)'></iframe>

WPF Label Foreground Color

I checked your XAML, it works fine - e.g. both labels have a gray foreground.
My guess is that you have some style which is affecting the way it looks...

Try moving your XAML to a brand-new window and see for yourself... Then, check if you have any themes or styles (in the Window.Resources for instance) which might be affecting the labels...

Printing object properties in Powershell

To print out object's properties and values in Powershell. Below examples work well for me.

$pool = Get-Item "IIS:\AppPools.NET v4.5"

$pool | Get-Member

   TypeName: Microsoft.IIs.PowerShell.Framework.ConfigurationElement#system.applicationHost/applicationPools#add

Name                        MemberType            Definition
----                        ----------            ----------
Recycle                     CodeMethod            void Recycle()
Start                       CodeMethod            void Start()
Stop                        CodeMethod            void Stop()
applicationPoolSid          CodeProperty          Microsoft.IIs.PowerShell.Framework.CodeProperty
state                       CodeProperty          Microsoft.IIs.PowerShell.Framework.CodeProperty
ClearLocalData              Method                void ClearLocalData()
Copy                        Method                void Copy(Microsoft.IIs.PowerShell.Framework.ConfigurationElement ...
Delete                      Method                void Delete()
...

$pool | Select-Object -Property * # You can omit -Property

name                        : .NET v4.5
queueLength                 : 1000
autoStart                   : True
enable32BitAppOnWin64       : False
managedRuntimeVersion       : v4.0
managedRuntimeLoader        : webengine4.dll
enableConfigurationOverride : True
managedPipelineMode         : Integrated
CLRConfigFile               :
passAnonymousToken          : True
startMode                   : OnDemand
state                       : Started
applicationPoolSid          : S-1-5-82-271721585-897601226-2024613209-625570482-296978595
processModel                : Microsoft.IIs.PowerShell.Framework.ConfigurationElement
...

Call angularjs function using jquery/javascript

Your plunker is firing off

angular.element(document.getElementById('MyController')).scope().myfunction('test');

Before anything is rendered.

You can verify that by wrapping it in a timeout

setTimeout(function() {
   angular.element(document.getElementById('MyController')).scope().myfunction('test');    
}, 1000);

You also need to acutally add an ID to your div.

<div ng-app='MyModule' ng-controller="MyController" id="MyController">

Pass props to parent component in React.js

Edit: see the end examples for ES6 updated examples.

This answer simply handle the case of direct parent-child relationship. When parent and child have potentially a lot of intermediaries, check this answer.

Other solutions are missing the point

While they still work fine, other answers are missing something very important.

Is there not a simple way to pass a child's props to its parent using events, in React.js?

The parent already has that child prop!: if the child has a prop, then it is because its parent provided that prop to the child! Why do you want the child to pass back the prop to the parent, while the parent obviously already has that prop?

Better implementation

Child: it really does not have to be more complicated than that.

var Child = React.createClass({
  render: function () {
    return <button onClick={this.props.onClick}>{this.props.text}</button>;
  },
});

Parent with single child: using the value it passes to the child

var Parent = React.createClass({
  getInitialState: function() {
     return {childText: "Click me! (parent prop)"};
  },
  render: function () {
    return (
      <Child onClick={this.handleChildClick} text={this.state.childText}/>
    );
  },
  handleChildClick: function(event) {
     // You can access the prop you pass to the children 
     // because you already have it! 
     // Here you have it in state but it could also be
     //  in props, coming from another parent.
     alert("The Child button text is: " + this.state.childText);
     // You can also access the target of the click here 
     // if you want to do some magic stuff
     alert("The Child HTML is: " + event.target.outerHTML);
  }
});

JsFiddle

Parent with list of children: you still have everything you need on the parent and don't need to make the child more complicated.

var Parent = React.createClass({
  getInitialState: function() {
     return {childrenData: [
         {childText: "Click me 1!", childNumber: 1},
         {childText: "Click me 2!", childNumber: 2}
     ]};
  },
  render: function () {
    var children = this.state.childrenData.map(function(childData,childIndex) {
        return <Child onClick={this.handleChildClick.bind(null,childData)} text={childData.childText}/>;
    }.bind(this));
    return <div>{children}</div>;
  },

  handleChildClick: function(childData,event) {
     alert("The Child button data is: " + childData.childText + " - " + childData.childNumber);
     alert("The Child HTML is: " + event.target.outerHTML);
  }
});

JsFiddle

It is also possible to use this.handleChildClick.bind(null,childIndex) and then use this.state.childrenData[childIndex]

Note we are binding with a null context because otherwise React issues a warning related to its autobinding system. Using null means you don't want to change the function context. See also.

About encapsulation and coupling in other answers

This is for me a bad idea in term of coupling and encapsulation:

var Parent = React.createClass({
  handleClick: function(childComponent) {
     // using childComponent.props
     // using childComponent.refs.button
     // or anything else using childComponent
  },
  render: function() {
    <Child onClick={this.handleClick} />
  }
});

Using props: As I explained above, you already have the props in the parent so it's useless to pass the whole child component to access props.

Using refs: You already have the click target in the event, and in most case this is enough. Additionnally, you could have used a ref directly on the child:

<Child ref="theChild" .../>

And access the DOM node in the parent with

React.findDOMNode(this.refs.theChild)

For more advanced cases where you want to access multiple refs of the child in the parent, the child could pass all the dom nodes directly in the callback.

The component has an interface (props) and the parent should not assume anything about the inner working of the child, including its inner DOM structure or which DOM nodes it declares refs for. A parent using a ref of a child means that you tightly couple the 2 components.

To illustrate the issue, I'll take this quote about the Shadow DOM, that is used inside browsers to render things like sliders, scrollbars, video players...:

They created a boundary between what you, the Web developer can reach and what’s considered implementation details, thus inaccessible to you. The browser however, can traipse across this boundary at will. With this boundary in place, they were able to build all HTML elements using the same good-old Web technologies, out of the divs and spans just like you would.

The problem is that if you let the child implementation details leak into the parent, you make it very hard to refactor the child without affecting the parent. This means as a library author (or as a browser editor with Shadow DOM) this is very dangerous because you let the client access too much, making it very hard to upgrade code without breaking retrocompatibility.

If Chrome had implemented its scrollbar letting the client access the inner dom nodes of that scrollbar, this means that the client may have the possibility to simply break that scrollbar, and that apps would break more easily when Chrome perform its auto-update after refactoring the scrollbar... Instead, they only give access to some safe things like customizing some parts of the scrollbar with CSS.

About using anything else

Passing the whole component in the callback is dangerous and may lead novice developers to do very weird things like calling childComponent.setState(...) or childComponent.forceUpdate(), or assigning it new variables, inside the parent, making the whole app much harder to reason about.


Edit: ES6 examples

As many people now use ES6, here are the same examples for ES6 syntax

The child can be very simple:

const Child = ({
  onClick, 
  text
}) => (
  <button onClick={onClick}>
    {text}
  </button>
)

The parent can be either a class (and it can eventually manage the state itself, but I'm passing it as props here:

class Parent1 extends React.Component {
  handleChildClick(childData,event) {
     alert("The Child button data is: " + childData.childText + " - " + childData.childNumber);
     alert("The Child HTML is: " + event.target.outerHTML);
  }
  render() {
    return (
      <div>
        {this.props.childrenData.map(child => (
          <Child
            key={child.childNumber}
            text={child.childText} 
            onClick={e => this.handleChildClick(child,e)}
          />
        ))}
      </div>
    );
  }
}

But it can also be simplified if it does not need to manage state:

const Parent2 = ({childrenData}) => (
  <div>
     {childrenData.map(child => (
       <Child
         key={child.childNumber}
         text={child.childText} 
         onClick={e => {
            alert("The Child button data is: " + child.childText + " - " + child.childNumber);
                    alert("The Child HTML is: " + e.target.outerHTML);
         }}
       />
     ))}
  </div>
)

JsFiddle


PERF WARNING (apply to ES5/ES6): if you are using PureComponent or shouldComponentUpdate, the above implementations will not be optimized by default because using onClick={e => doSomething()}, or binding directly during the render phase, because it will create a new function everytime the parent renders. If this is a perf bottleneck in your app, you can pass the data to the children, and reinject it inside "stable" callback (set on the parent class, and binded to this in class constructor) so that PureComponent optimization can kick in, or you can implement your own shouldComponentUpdate and ignore the callback in the props comparison check.

You can also use Recompose library, which provide higher order components to achieve fine-tuned optimisations:

// A component that is expensive to render
const ExpensiveComponent = ({ propA, propB }) => {...}

// Optimized version of same component, using shallow comparison of props
// Same effect as React's PureRenderMixin
const OptimizedComponent = pure(ExpensiveComponent)

// Even more optimized: only updates if specific prop keys have changed
const HyperOptimizedComponent = onlyUpdateForKeys(['propA', 'propB'])(ExpensiveComponent)

In this case you could optimize the Child component by using:

const OptimizedChild = onlyUpdateForKeys(['text'])(Child)

How to gzip all files in all sub-directories into one compressed file in bash

@amitchhajer 's post works for GNU tar. If someone finds this post and needs it to work on a NON GNU system, they can do this:

tar cvf - folderToCompress | gzip > compressFileName

To expand the archive:

zcat compressFileName | tar xvf -

problem with php mail 'From' header

It turns out the original poster's server (blueHost) has a FAQ concerning this very question.

Article 206.


This is because our servers require you (or your script) to use a properly formatted, valid From: field in the email's header. If the From: field is not formatted correctly, empty or the email address does not exist in the cPanel, the From: address will be changed to username@box###.bluehost.com.

You must change the script you are using to correctly use a valid From: header.

Examples of headers that should work would be:

From: [email protected]
From: "user" <[email protected]>

Examples of headers that will NOT work:

From: "[email protected]"
From: user @ domain.com
From: [email protected] <[email protected]>

Our servers will not accept the name for the email address and the email address to be the same. It will not accept a double declaration of the email address.

For scripts such as Joomla and Wordpress, you will need to follow their documentation for formatting the from fields properly. Wordpress will require the Mail From plugin.

Note: The email address you use must be a valid created account in the cPanel.

Difference between Activity Context and Application Context

The reason I think is that ProgressDialog is attached to the activity that props up the ProgressDialog as the dialog cannot remain after the activity gets destroyed so it needs to be passed this(ActivityContext) that also gets destroyed with the activity whereas the ApplicationContext remains even after the activity gets destroyed.

Get Unix timestamp with C++

Windows uses a different epoch and time units: see Convert Windows Filetime to second in Unix/Linux

What std::time() returns on Windows is (as yet) unknown to me (;-))

AngularJS: No "Access-Control-Allow-Origin" header is present on the requested resource

CORS is Cross Origin Resource Sharing, you get this error if you are trying to access from one domain to another domain.

Try using JSONP. In your case, JSONP should work fine because it only uses the GET method.

Try something like this:

var url = "https://api.getevents.co/event?&lat=41.904196&lng=12.465974";
$http({
    method: 'JSONP',
    url: url
}).
success(function(status) {
    //your code when success
}).
error(function(status) {
    //your code when fails
});

Can Flask have optional URL parameters?

I know this post is really old but I worked on a package that does this called flask_optional_routes. The code is located at: https://github.com/sudouser2010/flask_optional_routes.

from flask import Flask

from flask_optional_routes import OptionalRoutes


app = Flask(__name__)
optional = OptionalRoutes(app)

@optional.routes('/<user_id>/<user_name>?/')
def foobar(user_id, user_name=None):
    return 'it worked!'

if __name__ == "__main__":
    app.run(host='0.0.0.0', port=5000)

How to encode URL to avoid special characters in Java?

URL construction is tricky because different parts of the URL have different rules for what characters are allowed: for example, the plus sign is reserved in the query component of a URL because it represents a space, but in the path component of the URL, a plus sign has no special meaning and spaces are encoded as "%20".

RFC 2396 explains (in section 2.4.2) that a complete URL is always in its encoded form: you take the strings for the individual components (scheme, authority, path, etc.), encode each according to its own rules, and then combine them into the complete URL string. Trying to build a complete unencoded URL string and then encode it separately leads to subtle bugs, like spaces in the path being incorrectly changed to plus signs (which an RFC-compliant server will interpret as real plus signs, not encoded spaces).

In Java, the correct way to build a URL is with the URI class. Use one of the multi-argument constructors that takes the URL components as separate strings, and it'll escape each component correctly according to that component's rules. The toASCIIString() method gives you a properly-escaped and encoded string that you can send to a server. To decode a URL, construct a URI object using the single-string constructor and then use the accessor methods (such as getPath()) to retrieve the decoded components.

Don't use the URLEncoder class! Despite the name, that class actually does HTML form encoding, not URL encoding. It's not correct to concatenate unencoded strings to make an "unencoded" URL and then pass it through a URLEncoder. Doing so will result in problems (particularly the aforementioned one regarding spaces and plus signs in the path).

Sorting using Comparator- Descending order (User defined classes)

The java.util.Collections class has a sort method that takes a list and a custom Comparator. You can define your own Comparator to sort your Person object however you like.

Embed youtube videos that play in fullscreen automatically

This was pretty well answered over here: How to make a YouTube embedded video a full page width one?

If you add '?rel=0&autoplay=1' to the end of the url in the embed code (like this)

<iframe id="video" src="//www.youtube.com/embed/5iiPC-VGFLU?rel=0&autoplay=1" frameborder="0" allowfullscreen></iframe>

of the video it should play on load. Here's a demo over at jsfiddle.

forward declaration of a struct in C?

A struct (without a typedef) often needs to (or should) be with the keyword struct when used.

struct A;                      // forward declaration
void function( struct A *a );  // using the 'incomplete' type only as pointer

If you typedef your struct you can leave out the struct keyword.

typedef struct A A;          // forward declaration *and* typedef
void function( A *a );

Note that it is legal to reuse the struct name

Try changing the forward declaration to this in your code:

typedef struct context context;

It might be more readable to do add a suffix to indicate struct name and type name:

typedef struct context_s context_t;

Check if object value exists within a Javascript array of objects and if not add a new object to array

This is what I did in addition to @sagar-gavhane's answer

const newUser = {_id: 4, name: 'Adam'}
const users = [{_id: 1, name: 'Fred'}, {_id: 2, name: 'Ted'}, {_id: 3, name:'Bill'}]

const userExists = users.some(user => user.name === newUser.name);
if(userExists) {
    return new Error({error:'User exists'})
}
users.push(newUser)

How to increase scrollback buffer size in tmux?

This builds on ntc2 and Chris Johnsen's answer. I am using this whenever I want to create a new session with a custom history-limit. I wanted a way to create sessions with limited scrollback without permanently changing my history-limit for future sessions.

tmux set-option -g history-limit 100 \; new-session -s mysessionname \; set-option -g history-limit 2000

This works whether or not there are existing sessions. After setting history-limit for the new session it resets it back to the default which for me is 2000.

I created an executable bash script that makes this a little more useful. The 1st parameter passed to the script sets the history-limit for the new session and the 2nd parameter sets its session name:

#!/bin/bash
tmux set-option -g history-limit "${1}" \; new-session -s "${2}" \; set-option -g history-limit 2000

Phone validation regex

The following regex matches a '+' followed by n digits


    var mobileNumber = "+18005551212";
    var regex = new RegExp("^\\+[0-9]*$");
    var OK = regex.test(mobileNumber);

    if (OK) {
      console.log("is a phone number");
    } else {
      console.log("is NOT a phone number");  
    }

Make a div fill up the remaining width

Up-to-date solution (October 2014) : ready for fluid layouts


Introduction:

This solution is even simpler than the one provided by Leigh. It is actually based on it.

Here you can notice that the middle element (in our case, with "content__middle" class) does not have any dimensional property specified - no width, nor padding, nor margin related property at all - but only an overflow: auto; (see note 1).

The great advantage is that now you can specify a max-width and a min-width to your left & right elements. Which is fantastic for fluid layouts.. hence responsive layout :-)

note 1: versus Leigh's answer where you need to add the margin-left & margin-right properties to the "content__middle" class.


Code with non-fluid layout:

Here the left & right elements (with classes "content__left" and "content__right") have a fixed width (in pixels): hence called non-fluid layout.

Live Demo on http://jsbin.com/qukocefudusu/1/edit?html,css,output

<style>
    /*
     * [1] & [3] "floats" makes the 2 divs align themselves respectively right & left
     * [2] "overflow: auto;" makes this div take the remaining width
     */
    .content {
        width: 100%;
    }
    .content__left {
        width: 100px;
        float: left; /* [1] */
        background-color: #fcc;
    }
    .content__middle {
        background-color: #cfc;
        overflow: auto; /* [2] */
    }
    .content__right {
        width: 100px;
        float: right; /* [3] */
        background-color: #ccf;
    }
</style>

<div class="content">
    <div class="content__left">
        left div<br/>left div<br/>left div<br/>left div<br/>left div<br/>left div<br/>
    </div>
    <div class="content__right">
        right div<br/>right div<br/>right div<br/>right div<br/>
    </div>
    <div class="content__middle">
        middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br />bit taller
    </div>
</div>

Code with fluid layout:

Here the left & right elements (with classes "content__left" and "content__right") have a variable width (in percentages) but also a minimum and maximum width: hence called fluid layout.

Live Demo in a fluid layout with the max-width properties http://jsbin.com/runahoremuwu/1/edit?html,css,output

<style>
    /*
     * [1] & [3] "floats" makes the 2 divs align themselves respectively right & left
     * [2] "overflow: auto;" makes this div take the remaining width
     */
    .content { 
        width: 100%; 
    }
    .content__left { 
        width: 20%; 
        max-width: 170px;  
        min-width: 40px;  
        float: left; /* [1] */
        background-color: #fcc; 
     }
    .content__middle { 
        background-color: #cfc; 
        overflow: auto; /* [2] */
    }
    .content__right { 
        width: 20%; 
        max-width: 250px; 
        min-width: 80px; 
        float: right; /* [3] */
        background-color: #ccf; 
    }
</style>

<div class="content">
    <div class="content__left">
        max-width of 170px & min-width of 40px<br />left div<br/>left div<br/>left div<br/>left div<br/>left div<br/>left div<br/>
    </div>
    <div class="content__right">
        max-width of 250px & min-width of 80px<br />right div<br/>right div<br/>right div<br/>right div<br/>
    </div>
    <div class="content__middle">
        middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br/>middle div<br />bit taller
    </div>
</div>

Browser Support

Tested on BrowserStack.com on the following web browsers:

  • IE7 to IE11
  • Ff 20, Ff 28
  • Safari 4.0 (windows XP), Safari 5.1 (windows XP)
  • Chrome 20, Chrome 25, Chrome 30, Chrome 33,
  • Opera 20

C compiler for Windows?

Be careful to use a C compiler, not C++ if you're actually doing C. While most programs in C will work using a C++ compiler there are enough differences that there can be problems. I would agree with the people who suggest using gcc via cygwin.

EDIT:
http://en.wikipedia.org/wiki/Compatibility_of_C_and_C%2B%2B shows some of the major differences

What is the 'realtime' process priority setting for?

Real-time is the highest priority class available to a process. Therefore, it is different from 'High' in that it's one step greater, and 'Above Normal' in that it's two steps greater.

Similarly, real-time is also a thread priority level.

The process priority class raises or lowers all effective thread priorities in the process and is therefore considered the 'base priority'.

So, a process has a:

  1. Base process priority class.
  2. Individual thread priorities, offsets of the base priority class.

Since real-time is supposed to be reserved for applications that absolutely must pre-empt other running processes, there is a special security privilege to protect against haphazard use of it. This is defined by the security policy.

In NT6+ (Vista+), use of the Vista Multimedia Class Scheduler is the proper way to achieve real-time operations in what is not a real-time OS. It works, for the most part, though is not perfect since the OS isn't designed for real-time operations.

Microsoft considers this priority very dangerous, rightly so. No application should use it except in very specialized circumstances, and even then try to limit its use to temporary needs.

How to Retrieve value from JTextField in Java Swing?

* First we declare JTextField like this

 JTextField  testField = new JTextField(10);

* We can get textfield value in String like this on any button click event.

button.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent ae){
      String getValue = testField.getText()

   }
})

Using BeautifulSoup to search HTML for string

In addition to the accepted answer. You can use a lambda instead of regex:

from bs4 import BeautifulSoup

html = """<p>test python</p>"""

soup = BeautifulSoup(html, "html.parser")

print(soup(text="python"))
print(soup(text=lambda t: "python" in t))

Output:

[]
['test python']

Best timestamp format for CSV/Excel?

I believe if you used the double data type, the re-calculation in Excel would work just fine.

How to change color of Toolbar back button in Android?

To style the Toolbar on Android 21+ it's a bit different.

<style name="DarkTheme.v21" parent="DarkTheme.v19">
        <!-- toolbar background color -->
        <item name="android:navigationBarColor">@color/color_primary_blue_dark</item>
        <!-- toolbar back button color -->
        <item name="toolbarNavigationButtonStyle">@style/Toolbar.Button.Navigation.Tinted</item>
    </style>

    <style name="Toolbar.Button.Navigation.Tinted" parent="Widget.AppCompat.Toolbar.Button.Navigation">
        <item name="tint">@color/color_white</item>
    </style>

Java read file and store text in an array

while(inFile1.hasNext()){

    token1 = inFile1.nextLine();

    // put each value into an array with String#split();
    String[] numStrings = line.split(", ");

    // parse number string into doubles 
    double[] nums = new double[numString.length];

    for (int i = 0; i < nums.length; i++){
        nums[i] = Double.parseDouble(numStrings[i]);
    }

}

There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'xxx'

In my case there was a conflict in the namespaces , I have:

using System.Web.Mvc;

and

using System.Collections.Generic;

I explicitly want to use the Mvc one so I declared it as :

new System.Web.Mvc.SelectList(...)

Check if a specific value exists at a specific key in any subarray of a multidimensional array

Nothing will be faster than a simple loop. You can mix-and-match some array functions to do it, but they'll just be implemented as a loop too.

function whatever($array, $key, $val) {
    foreach ($array as $item)
        if (isset($item[$key]) && $item[$key] == $val)
            return true;
    return false;
}

Automatic Preferred Max Layout Width is not available on iOS versions prior to 8.0

I had this issue and was able to fix it by adding constraints to determine the max with for a label.

When dropping a multiline label in there is not constraint set to enforce the width inside the parent view. This is where the new PreferredMaxWidth comes into play. On iOS 7 and earlier you have to define the max width yourself. I simply added a 10px constraint to the left and right hand side of the label.

You can also add a <= width constraint which also fixes the issue.

So this is not actually a bug, you simply have to define the max width yourself. The explicit option mention in other answer will also work as you are setting this width value however you will have to modify this value if you want the max width to change based on the parent width (as you have explicitly set the width).

My above solution ensures the width is always maintained no matter how big the parent view is.

Refresh Page C# ASP.NET

Call Page_load function:

Page_Load(sender, e);

How do I catch an Ajax query post error?

Since jQuery 1.5 you can use the deferred objects mechanism:

$.post('some.php', {name: 'John'})
    .done(function(msg){  })
    .fail(function(xhr, status, error) {
        // error handling
    });

Another way is using .ajax:

$.ajax({
  type: "POST",
  url: "some.php",
  data: "name=John&location=Boston",
  success: function(msg){
        alert( "Data Saved: " + msg );
  },
  error: function(XMLHttpRequest, textStatus, errorThrown) {
     alert("some error");
  }
});

Adjust icon size of Floating action button (fab)

Try to use app:maxImageSize="56dp" instead of the above answers after you update your support library to v28.0.0

How to install latest version of Node using Brew

if the node is not installed then

brew install node

If you have an older version of node install then remove it and install freshly that's the only suitable way.

Make sure to add the path in the environment file.

How to set shape's opacity?

Use this one, I've written this to my app,

<?xml version="1.0" encoding="utf-8"?>
<!--  res/drawable/rounded_edittext.xml -->
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" android:padding="10dp">
    <solid android:color="#882C383E"/>
    <corners
        android:bottomRightRadius="5dp"
        android:bottomLeftRadius="5dp"
        android:topLeftRadius="5dp"
        android:topRightRadius="5dp"/>
</shape>

Simulating group_concat MySQL function in Microsoft SQL Server 2005?

I may be a bit late to the party but this method works for me and is easier than the COALESCE method.

SELECT STUFF(
             (SELECT ',' + Column_Name 
              FROM Table_Name
              FOR XML PATH (''))
             , 1, 1, '')

When to choose mouseover() and hover() function?

You can try it out http://api.jquery.com/mouseover/ on the jQuery doc page. It's a nice little, interactive demo that makes it very clear and you can actually see for yourself.

In short, you'll notice that a mouse over event occurs on an element when you are over it - coming from either its child OR parent element, but a mouse enter event only occurs when the mouse moves from the parent element to the element.