SyntaxFix

Programs & Examples On #Catalina

Catalina is Tomcat's component that interacts with Java servlets

Tomcat won't stop or restart

Follow this :)

  1. Open : /etc/systemd/system/tomcat.service

Can you see JAVA_HOME ? : modify it like below

Environment="JAVA_HOME=/usr/lib/jvm/java-1.11.0-openjdk-amd64"

At 1.11.0 - insert your own Jdk version

  1. systemctl daemon-reload

  2. sudo systemctl start tomcat

Now, in eclipse -> Add Server -> .....

Got struck at tomcat installation directory ??

  1. Extract the tomcat tar file you already downloaded.
  2. Now go back to eclipse -> add server -> Browse -> Point to extracted file (done in step 1 above :)

Comment if you get struck in somewhere else too )

How to set CATALINA_HOME variable in windows 7?

There is no requirement of setting CATALINA-HOME.

Follow below instruction .

Right click on computer --> properties --> Advanced system setting --> Environment variables.

User variables section --> click on "New" --> variable name : CLASSPATH , variable value : D:\java\lib*.;D:\tomcat8\lib\servlet-api.jar.; --> Click "Ok"

New --> variable name : PATH , variable value : D:\java\bin; --> Click "Ok"

System variables section:-

Click on "New" --> variable name : PATH , variable value : D:\java\jre --> Click "Ok"

I've installed java and tomcat in D drive henceforth the locations above are under my respective paths.

Give location paths where java and tomcat are installed in your PC. Thank You

Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JDBC_DBO]]

Just clean your server (in my case I was using Tomcat):

mvn clean
mvn install

Pandas index column title or name

Setting the index name can also be accomplished at creation:

pd.DataFrame(data={'age': [10,20,30], 'height': [100, 170, 175]}, index=pd.Series(['a', 'b', 'c'], name='Tag'))

How to match, but not capture, part of a regex?

A variation of the expression by @Gumbo that makes use of \K for resetting match positions to prevent the inclusion of number blocks in the match. Usable in PCRE regex flavours.

123-\K(?:(?:apple|banana)(?=-456)|456\K)

Matches:

Match 1  apple
Match 2  banana
Match 3

Regular expression \p{L} and \p{N}

\p{L} matches a single code point in the category "letter".
\p{N} matches any kind of numeric character in any script.

Source: regular-expressions.info

If you're going to work with regular expressions a lot, I'd suggest bookmarking that site, it's very useful.

How to configure encoding in Maven?

Try this:

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-resources-plugin</artifactId>
        <version>2.7</version>
        <configuration>
          ...
          <encoding>UTF-8</encoding>
          ...
        </configuration>
      </plugin>
    </plugins>
    ...
  </build>
  ...
</project>

Command line to remove an environment variable from the OS level configuration

I agree with CupawnTae.

SET is not useful for changes to the master environment.

FYI: System variables are in HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment (a good deal longer than user vars).

The full command for a system var named FOOBAR therefore is:

REG delete "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /F /V FOOBAR

(Note the quotes required to handle the space.)

It is too bad the setx command doesn't support a delete syntax. :(

PS: Use responsibly - If you kill your path variable, don't blame me!

Angular 2 Hover event

yes there is on-mouseover in angular2 instead of ng-Mouseover like in angular 1.x so you have to write this :-

<div on-mouseover='over()' style="height:100px; width:100px; background:#e2e2e2">hello mouseover</div>

over(){
    console.log("Mouseover called");
  }

As @Gunter Suggested in comment there is alternate of on-mouseover we can use this too. Some people prefer the on- prefix alternative, known as the canonical form.

Update

HTML Code -

<div (mouseover)='over()' (mouseout)='out()' style="height:100px; width:100px; background:#e2e2e2">hello mouseover</div>

Controller/.TS Code -

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

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  name = 'Angular';

  over(){
    console.log("Mouseover called");
  }

  out(){
    console.log("Mouseout called");
  }
}

Working Example

Some other Mouse events can be used in Angular -

(mouseenter)="myMethod()"
(mousedown)="myMethod()"
(mouseup)="myMethod()"

AngularJS : Factory and Service?

Service vs Factory

enter image description here enter image description here

The difference between factory and service is just like the difference between a function and an object

Factory Provider

  • Gives us the function's return value ie. You just create an object, add properties to it, then return that same object.When you pass this service into your controller, those properties on the object will now be available in that controller through your factory. (Hypothetical Scenario)

  • Singleton and will only be created once

  • Reusable components

  • Factory are a great way for communicating between controllers like sharing data.

  • Can use other dependencies

  • Usually used when the service instance requires complex creation logic

  • Cannot be injected in .config() function.

  • Used for non configurable services

  • If you're using an object, you could use the factory provider.

  • Syntax: module.factory('factoryName', function);

Service Provider

  • Gives us the instance of a function (object)- You just instantiated with the ‘new’ keyword and you’ll add properties to ‘this’ and the service will return ‘this’.When you pass the service into your controller, those properties on ‘this’ will now be available on that controller through your service. (Hypothetical Scenario)

  • Singleton and will only be created once

  • Reusable components

  • Services are used for communication between controllers to share data

  • You can add properties and functions to a service object by using the this keyword

  • Dependencies are injected as constructor arguments

  • Used for simple creation logic

  • Cannot be injected in .config() function.

  • If you're using a class you could use the service provider

  • Syntax: module.service(‘serviceName’, function);

Sample Demo

In below example I have define MyService and MyFactory. Note how in .service I have created the service methods using this.methodname. In .factory I have created a factory object and assigned the methods to it.

AngularJS .service

module.service('MyService', function() {

    this.method1 = function() {
            //..method1 logic
        }

    this.method2 = function() {
            //..method2 logic
        }
});

AngularJS .factory

module.factory('MyFactory', function() {

    var factory = {}; 

    factory.method1 = function() {
            //..method1 logic
        }

    factory.method2 = function() {
            //..method2 logic
        }

    return factory;
});

Also Take a look at this beautiful stuffs

Confused about service vs factory

AngularJS Factory, Service and Provider

Angular.js: service vs provider vs factory?

ActiveMQ connection refused

I had also similar problem. In my case brokerUrl was not configured properly. So that's way I received following Error:

Cause: Error While attempting to add new Connection to the pool: nested exception is javax.jms.JMSException: Could not connect to broker URL : tcp://localhost:61616. Reason: java.net.ConnectException: Connection refused

& I resolved it following way.

   ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory();

  connectionFactory.setBrokerURL("tcp://hostname:61616");
  connectionFactory.setUserName("admin");
  connectionFactory.setPassword("admin");

How to add \newpage in Rmarkdown in a smart way?

In the initialization chunk I define a function

pagebreak <- function() {
  if(knitr::is_latex_output())
    return("\\newpage")
  else
    return('<div style="page-break-before: always;" />')
}

In the markdown part where I want to insert a page break, I type 

`r pagebreak()`

How do I call a SQL Server stored procedure from PowerShell?

This answer was pulled from http://www.databasejournal.com/features/mssql/article.php/3683181

This same example can be used for any adhoc queries. Let us execute the stored procedure “sp_helpdb” as shown below.

$SqlConnection = New-Object System.Data.SqlClient.SqlConnection
$SqlConnection.ConnectionString = "Server=HOME\SQLEXPRESS;Database=master;Integrated Security=True"
$SqlCmd = New-Object System.Data.SqlClient.SqlCommand
$SqlCmd.CommandText = "sp_helpdb"
$SqlCmd.Connection = $SqlConnection
$SqlAdapter = New-Object System.Data.SqlClient.SqlDataAdapter
$SqlAdapter.SelectCommand = $SqlCmd
$DataSet = New-Object System.Data.DataSet
$SqlAdapter.Fill($DataSet)
$SqlConnection.Close()
$DataSet.Tables[0]

How to detect simple geometric shapes using OpenCV

If you have only these regular shapes, there is a simple procedure as follows :

  1. Find Contours in the image ( image should be binary as given in your question)
  2. Approximate each contour using approxPolyDP function.
  3. First, check number of elements in the approximated contours of all the shapes. It is to recognize the shape. For eg, square will have 4, pentagon will have 5. Circles will have more, i don't know, so we find it. ( I got 16 for circle and 9 for half-circle.)
  4. Now assign the color, run the code for your test image, check its number, fill it with corresponding colors.

Below is my example in Python:

import numpy as np
import cv2

img = cv2.imread('shapes.png')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

ret,thresh = cv2.threshold(gray,127,255,1)

contours,h = cv2.findContours(thresh,1,2)

for cnt in contours:
    approx = cv2.approxPolyDP(cnt,0.01*cv2.arcLength(cnt,True),True)
    print len(approx)
    if len(approx)==5:
        print "pentagon"
        cv2.drawContours(img,[cnt],0,255,-1)
    elif len(approx)==3:
        print "triangle"
        cv2.drawContours(img,[cnt],0,(0,255,0),-1)
    elif len(approx)==4:
        print "square"
        cv2.drawContours(img,[cnt],0,(0,0,255),-1)
    elif len(approx) == 9:
        print "half-circle"
        cv2.drawContours(img,[cnt],0,(255,255,0),-1)
    elif len(approx) > 15:
        print "circle"
        cv2.drawContours(img,[cnt],0,(0,255,255),-1)

cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Below is the output:

enter image description here

Remember, it works only for regular shapes.

Alternatively to find circles, you can use houghcircles. You can find a tutorial here.

Regarding iOS, OpenCV devs are developing some iOS samples this summer, So visit their site : www.code.opencv.org and contact them.

You can find slides of their tutorial here : http://code.opencv.org/svn/gsoc2012/ios/trunk/doc/CVPR2012_OpenCV4IOS_Tutorial.pdf

Executing a shell script from a PHP script

Without really knowing the complexity of the setup, I like the sudo route. First, you must configure sudo to permit your webserver to sudo run the given command as root. Then, you need to have the script that the webserver shell_exec's(testscript) run the command with sudo.

For A Debian box with Apache and sudo:

  1. Configure sudo:

    • As root, run the following to edit a new/dedicated configuration file for sudo:

      visudo -f /etc/sudoers.d/Webserver

      (or whatever you want to call your file in /etc/sudoers.d/)

    • Add the following to the file:

      www-data ALL = (root) NOPASSWD: <executable_file_path>

      where <executable_file_path> is the command that you need to be able to run as root with the full path in its name(say /bin/chown for the chown executable). If the executable will be run with the same arguments every time, you can add its arguments right after the executable file's name to further restrict its use.

      For example, say we always want to copy the same file in the /root/ directory, we would write the following:

      www-data ALL = (root) NOPASSWD: /bin/cp /root/test1 /root/test2

  2. Modify the script(testscript):

    Edit your script such that sudo appears before the command that requires root privileges(say sudo /bin/chown ... or sudo /bin/cp /root/test1 /root/test2). Make sure that the arguments specified in the sudo configuration file exactly match the arguments used with the executable in this file. So, for our example above, we would have the following in the script:

    sudo /bin/cp /root/test1 /root/test2

If you are still getting permission denied, the script file and it's parent directories' permissions may not allow the webserver to execute the script itself. Thus, you need to move the script to a more appropriate directory and/or change the script and parent directory's permissions to allow execution by www-data(user or group), which is beyond the scope of this tutorial.

Keep in mind:

When configuring sudo, the objective is to permit the command in it's most restricted form. For example, instead of permitting the general use of the cp command, you only allow the cp command if the arguments are, say, /root/test1 /root/test2. This means that cp's arguments(and cp's functionality cannot be altered).

Embed Google Map code in HTML with marker

Learning Google's JavaScript library is a good option. If you don't feel like getting into coding you might find Maps Engine Lite useful.

It is a tool recently published by Google where you can create your personal maps (create markers, draw geometries and adapt the colors and styles).

Here is an useful tutorial I found: Quick Tip: Embedding New Google Maps

PDO get the last ID inserted

You can get the id of the last transaction by running lastInsertId() method on the connection object($conn).

Like this $lid = $conn->lastInsertId();

Please check out the docs https://www.php.net/manual/en/language.oop5.basic.php

How do I detect a page refresh using jquery?

 
$('body').bind('beforeunload',function(){
   //do something
});

But this wont save any info for later, unless you were planning on saving that in a cookie somewhere (or local storage) and the unload event does not always fire in all browsers.

Example: http://jsfiddle.net/maniator/qpK7Y/

Code: 

$(window).bind('beforeunload',function(){

     //save info somewhere

    return 'are you sure you want to leave?';

});

Maximum request length exceeded.

It bothered me for days too. I modified the Web.config file but it didn't work. It turned out that there are two Web.config file in my project, and I should modified the one in the ROOT directory, not the others. Hope this would be helpful.

SQL: How to to SUM two values from different tables

For your current structure, you could also try the following:

select cash.Country, cash.Value, cheque.Value, cash.Value + cheque.Value as [Total]
from Cash
join Cheque
on cash.Country = cheque.Country

I think I prefer a union between the two tables, and a group by on the country name as mentioned above.

But I would also recommend normalising your tables. Ideally you'd have a country table, with Id and Name, and a payments table with: CountryId (FK to countries), Total, Type (cash/cheque)

How can I ask the Selenium-WebDriver to wait for few seconds in Java?

Sometimes implicit wait fails, saying that an element exists but it really doesn't.

The solution is to avoid using driver.findElement and to replace it with a custom method that uses an Explicit Wait implicitly. For example:

import org.openqa.selenium.NoSuchElementException;


public WebElement element(By locator){
    Integer timeoutLimitSeconds = 20;
    WebDriverWait wait = new WebDriverWait(driver, timeoutLimitSeconds);
    try {
        wait.until(ExpectedConditions.presenceOfElementLocated(locator));
    }
    catch(TimeoutException e){
        throw new NoSuchElementException(locator.toString());
    }
    WebElement element = driver.findElement(locator);
    return element;
}

There are additional reasons to avoid implicit wait other than sporadic, occasional failures (see this link).

You can use this "element" method in the same way as driver.findElement. For Example:

    driver.get("http://yoursite.html");
    element(By.cssSelector("h1.logo")).click();

If you really want to just wait a few seconds for troubleshooting or some other rare occasion, you can create a pause method similar to what selenium IDE offers:

    public void pause(Integer milliseconds){
    try {
        TimeUnit.MILLISECONDS.sleep(milliseconds);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

CSS - display: none; not working

Check following html I removed display:block from style

<div id="tfl" style="width: 187px; height: 260px; font-family: Verdana, Arial, Helvetica, sans-serif !important; background: url(http://www.tfl.gov.uk/tfl/gettingaround/journeyplanner/banners/images/widget-panel.gif) #fff no-repeat; font-size: 11px; border: 1px solid #103994; border-radius: 4px; box-shadow: 2px 2px 3px 1px #ccc;">
        <div style="display: block; padding: 30px 0 15px 0;">
            <h2 style="color: rgb(36, 66, 102); text-align: center; display: block; font-size: 15px; font-family: arial; border: 0; margin-bottom: 1em; margin-top: 0; font-weight: bold !important; background: 0; padding: 0">Journey Planner</h2>
            <form action="http://journeyplanner.tfl.gov.uk/user/XSLT_TRIP_REQUEST2" id="jpForm" method="post" target="tfl" style="margin: 5px 0 0 0 !important; padding: 0 !important;">
                <input type="hidden" name="language" value="en" />
                <!-- in language = english -->
                <input type="hidden" name="execInst" value="" /><input type="hidden" name="sessionID" value="0" />
                <!-- to start a new session on JP the sessionID has to be 0 -->
                <input type="hidden" name="ptOptionsActive" value="-1" />
                <!-- all pt options are active -->
                <input type="hidden" name="place_origin" value="London" />
                <!-- London is a hidden parameter for the origin location -->
                <input type="hidden" name="place_destination" value="London" /><div style="padding-right: 15px; padding-left: 15px">
                    <input type="text" name="name_origin" style="width: 155px !important; padding: 1px" value="From" /><select style="width: 155px !important; margin: 0 !important;" name="type_origin"><option value="stop">Station or stop</option>
                        <option value="locator">Postcode</option>
                        <option value="address">Address</option>
                        <option value="poi">Place of interest</option>
                    </select>
                </div>
                <div style="margin-top: 10px; margin-bottom: 4px; padding-right: 15px; padding-left: 15px; padding-bottom: 15px; background: url(http://www.tfl.gov.uk/tfl/gettingaround/journeyplanner/banners/images/panel-separator.gif) no-repeat bottom;">
                    <input type="text" name="name_destination" style="width: 100% !important; padding: 1px" value="232 Kingsbury Road (NW9)" /><select style="width: 155px !important; margin-top: 0 !important;" name="type_destination"><option value="stop">Station or stop</option>
                        <option value="locator">Postcode</option>
                        <option value="address" selected="selected">Address</option>
                        <option value="poi">Place of interest</option>
                    </select>
                </div>
                <div style="background: url(http://www.tfl.gov.uk/tfl/gettingaround/journeyplanner/banners/images/panel-separator.gif) no-repeat bottom; padding-bottom: 2px; padding-top: 2px; overflow: hidden; margin-bottom: 8px">
                    <div style="clear: both; background: url(http://www.tfl.gov.uk/tfl-global/images/options-icons.gif) no-repeat 9.5em 0; height: 30px; padding-right: 15px; padding-left: 15px"><a style="text-decoration: none; color: #113B92; font-size: 11px; white-space: nowrap; display: inline-block; padding: 4px 0 5px 0; width: 155px" target="tfl" href="http://journeyplanner.tfl.gov.uk/user/XSLT_TRIP_REQUEST2?language=en&amp;ptOptionsActive=1" onclick="javascript:document.getElementById('jpForm').ptOptionsActive.value='1';document.getElementById('jpForm').execInst.value='readOnly';document.getElementById('jpForm').submit(); return false">More options</a></div>
                </div>
                <div style="text-align: center;">
                    <input type="submit" title="Leave now" value="Leave now" style="border-style: none; background-color: #157DB9; display: inline-block; padding: 4px 11px; color: #fff; text-decoration: none; border-radius: 3px; border-radius: 3px; border-radius: 3px; box-shadow: 0 1px 3px rgba(0,0,0,0.25); box-shadow: 0 1px 3px rgba(0,0,0,0.25); box-shadow: 0 1px 3px rgba(0,0,0,0.25); text-shadow: 0 -1px 1px rgba(0,0,0,0.25); border-bottom: 1px solid rgba(0,0,0,0.25); position: relative; cursor: pointer; font: bold  13px/1 Arial,Helvetica,sans-serif; text-shadow: 1px 1px 1px rgba(0, 0, 0, 0.4); line-height: 1;" />
                </div>
            </form>
        </div>
    </div

Quick easy way to migrate SQLite3 to MySQL?

Probably the quick easiest way is using the sqlite .dump command, in this case create a dump of the sample database.

sqlite3 sample.db .dump > dump.sql

You can then (in theory) import this into the mysql database, in this case the test database on the database server 127.0.0.1, using user root.

mysql -p -u root -h 127.0.0.1 test < dump.sql

I say in theory as there are a few differences between grammars.

In sqlite transactions begin

BEGIN TRANSACTION;
...
COMMIT;

MySQL uses just 

BEGIN;
...
COMMIT;

There are other similar problems (varchars and double quotes spring back to mind) but nothing find and replace couldn't fix.

Perhaps you should ask why you are migrating, if performance/ database size is the issue perhaps look at reoginising the schema, if the system is moving to a more powerful product this might be the ideal time to plan for the future of your data.

Mark error in form using Bootstrap

Generally showing the error near where the error occurs is best. i.e. if someone has an error with entering their email, you highlight the email input box.

This article has a couple good examples. http://uxdesign.smashingmagazine.com/2011/05/27/getting-started-with-defensive-web-design/

Also twitter bootstrap has some nice styling that helps with that (scroll down to the Validation states section) http://twitter.github.com/bootstrap/base-css.html#forms

Highlighting each input box is a bit more complicated, so the easy way would be to just put an bootstrap alert at the top with details of what the user did wrong. http://twitter.github.com/bootstrap/components.html#alerts

How to check if bootstrap modal is open, so I can use jquery validate?

You can also directly use jQuery.

$('#myModal').is(':visible');

Show/hide image with JavaScript

This is working code:

<html>
  <body bgcolor=cyan>
    <img src ="backgr1.JPG" id="my" width="310" height="392" style="position: absolute; top:92px; left:375px; visibility:hidden"/>
    <script type="text/javascript">
      function tend() {
        document.getElementById('my').style.visibility='visible';
      }
      function tn() {
        document.getElementById('my').style.visibility='hidden';
      }
    </script>
    <input type="button" onclick="tend()" value="back">
    <input type="button" onclick="tn()" value="close">
  </body>
</html>

PHP CSV string to array

You can convert CSV string to Array with this function.

    function csv2array(
        $csv_string,
        $delimiter = ",",
        $skip_empty_lines = true,
        $trim_fields = true,
        $FirstLineTitle = false
    ) {
        $arr = array_map(
            function ( $line ) use ( &$result, &$FirstLine, $delimiter, $trim_fields, $FirstLineTitle ) {
                if ($FirstLineTitle && !$FirstLine) {
                    $FirstLine = explode( $delimiter, $result[0] );
                }
                $lineResult = array_map(
                    function ( $field ) {
                        return str_replace( '!!Q!!', '"', utf8_decode( urldecode( $field ) ) );
                    },
                    $trim_fields ? array_map( 'trim', explode( $delimiter, $line ) ) : explode( $delimiter, $line )
                );
                return $FirstLineTitle ? array_combine( $FirstLine, $lineResult ) : $lineResult;
            },
            ($result = preg_split(
                $skip_empty_lines ? ( $trim_fields ? '/( *\R)+/s' : '/\R+/s' ) : '/\R/s',
                preg_replace_callback(
                    '/"(.*?)"/s',
                    function ( $field ) {
                        return urlencode( utf8_encode( $field[1] ) );
                    },
                    $enc = preg_replace( '/(?<!")""/', '!!Q!!', $csv_string )
                )
            ))
        );
        return $FirstLineTitle ? array_splice($arr, 1) : $arr;
    }

How to get a random value from dictionary?

This works in Python 2 and Python 3:

A random key:

random.choice(list(d.keys()))

A random value

random.choice(list(d.values()))

A random key and value

random.choice(list(d.items()))

What is the difference between hg forget and hg remove?

If you use "hg remove b" against a file with "A" status, which means it has been added but not commited, Mercurial will respond: 

  not removing b: file has been marked for add (use forget to undo)

This response is a very clear explication of the difference between remove and forget.

My understanding is that "hg forget" is for undoing an added but not committed file so that it is not tracked by version control; while "hg remove" is for taking out a committed file from version control.

This thread has a example for using hg remove against files of 7 different types of status.

Check if a string is a palindrome

The various provided answers are wrong for numerous reasons, primarily from misunderstanding what a palindrome is. The majority only properly identify a subset of palindromes.

From Merriam-Webster

A word, verse, or sentence (such as "Able was I ere I saw Elba")

And from Wordnik

A word, phrase, verse, or sentence that reads the same backward or forward. For example: A man, a plan, a canal, Panama!

Consider non-trivial palindromes such as "Malayalam" (it's a proper language, so naming rules apply, and it should be capitalized), or palindromic sentences such as "Was it a car or a cat I saw?" or "No 'X' in Nixon".

These are recognized palindromes in any literature.

I'm lifting the thorough solution from a library providing this kind of stuff that I'm the primary author of, so the solution works for both String and ReadOnlySpan<Char> because that's a requirement I've imposed on the library. The solution for purely String will be easy to determine from this, however.

public static Boolean IsPalindrome(this String @string) =>
    !(@string is null) && @string.AsSpan().IsPalindrome();

public static Boolean IsPalindrome(this ReadOnlySpan<Char> span) {
    // First we need to build the string without any punctuation or whitespace or any other
    // unrelated-to-reading characters.
    StringBuilder builder = new StringBuilder(span.Length);
    foreach (Char s in span) {
        if (!(s.IsControl()
            || s.IsPunctuation()
            || s.IsSeparator()
            || s.IsWhiteSpace()) {
            _ = builder.Append(s);
        }
    }
    String prepped = builder.ToString();
    String reversed = prepped.Reverse().Join();
    // Now actually check it's a palindrome
    return String.Equals(prepped, reversed, StringComparison.CurrentCultureIgnoreCase);
}

You're going to want variants of this that accept a CultureInfo parameter as well, when you're testing a specific language rather than your own language, by instead calling .ToUpper(cultureInfo) on prepped.

And here's proof from the projects unit tests that it works.

unit test results

The remote server returned an error: (403) Forbidden

Setting:

request.Referer = @"http://www.somesite.com/";

and adding cookies than worked for me

How to Deserialize XML document

My solution:

  1. Use Edit > Past Special > Paste XML As Classes to get the class in your code
  2. Try something like this: create a list of that class (List<class1>), then use the XmlSerializer to serialize that list to a xml file.
  3. Now you just replace the body of that file with your data and try to deserialize it.

Code: 

StreamReader sr = new StreamReader(@"C:\Users\duongngh\Desktop\Newfolder\abc.txt");
XmlSerializer xml = new XmlSerializer(typeof(Class1[]));
var a = xml.Deserialize(sr);
sr.Close();

NOTE: you must pay attention to the root name, don't change it. Mine is "ArrayOfClass1"

How do I change Eclipse to use spaces instead of tabs?
  • Click Window » Preferences
  • Expand Java » Code Style
  • Click Formatter
  • click new
  • Select the profile name
  • Click ok
  • Click the Edit button
  • Click the Indentation tab
  • Under General Settings, set Tab policy to: Spaces only
  • Click OK.

How do I create executable Java program?

On the command line, navigate to the root directory of the Java files you wish to make executable.

Use this command:

jar -cvf [name of jar file] [name of directory with Java files]

This will create a directory called META-INF in the jar archive. In this META-INF there is a file called MANIFEST.MF, open this file in a text editor and add the following line:

Main-Class: [fully qualified name of your main class]

then use this command:

java -jar [name of jar file]

and your program will run :)

How to hide a div after some time period?

In older versions of jquery you'll have to do it the "javascript way" using settimeout 

setTimeout( function(){$('div').hide();} , 4000);

or

setTimeout( "$('div').hide();", 4000);

Recently with jquery 1.4 this solution has been added:

$("div").delay(4000).hide();

Of course replace "div" by the correct element using a valid jquery selector and call the function when the document is ready.

File Upload using AngularJS

in simple words

in Html - add below code only

     <form name="upload" class="form" data-ng-submit="addFile()">
  <input type="file" name="file" multiple 
 onchange="angular.element(this).scope().uploadedFile(this)" />
 <button type="submit">Upload </button>
</form>

in the controller - This function is called when you click "upload file button". it will upload the file. you can console it.

$scope.uploadedFile = function(element) {
$scope.$apply(function($scope) {
  $scope.files = element.files;         
});
}

add more in controllers - below code add into the function . This function is called when you click on button which is used "hitting the api (POST)". it will send file(which uploaded) and form-data to the backend . 

var url = httpURL + "/reporttojson"
        var files=$scope.files;

         for ( var i = 0; i < files.length; i++)
         {
            var fd = new FormData();
             angular.forEach(files,function(file){
             fd.append('file',file);
             });
             var data ={
              msg : message,
              sub : sub,
              sendMail: sendMail,
              selectUsersAcknowledge:false
             };

             fd.append("data", JSON.stringify(data));
              $http.post(url, fd, {
               withCredentials : false,
               headers : {
                'Content-Type' : undefined
               },
             transformRequest : angular.identity
             }).success(function(data)
             {
                  toastr.success("Notification sent successfully","",{timeOut: 2000});
                  $scope.removereport()
                   $timeout(function() {
                    location.reload();
                }, 1000);

             }).error(function(data)
             {
              toastr.success("Error in Sending Notification","",{timeOut: 2000});
              $scope.removereport()
             });
        }

in this case .. i added below code as form data

var data ={
          msg : message,
          sub : sub,
          sendMail: sendMail,
          selectUsersAcknowledge:false
         };

What is a vertical tab?

In the medical industry, VT is used as the start of frame character in the MLLP/LLP/HLLP protocols that are used to frame HL-7 data, which has been a standard for medical exchange since the late 80s and is still in wide use.

How do I convert an interval into a number of hours with postgres?

 
select floor((date_part('epoch', order_time - '2016-09-05 00:00:00') / 3600)), count(*)
from od_a_week
group by floor((date_part('epoch', order_time - '2016-09-05 00:00:00') / 3600));

The ::int conversion follows the principle of rounding. If you want a different result such as rounding down, you can use the corresponding math function such as floor.

minimize app to system tray

This is the method I use in my applications, it's fairly simple and self explanatory but I'm happy to give more details in answer to your comments.

    public Form1()
    {
        InitializeComponent();

        // When window state changed, trigger state update.
        this.Resize += SetMinimizeState;

        // When tray icon clicked, trigger window state change.       
        systemTrayIcon.Click += ToggleMinimizeState;
    }      

    // Toggle state between Normal and Minimized.
    private void ToggleMinimizeState(object sender, EventArgs e)
    {    
        bool isMinimized = this.WindowState == FormWindowState.Minimized;
        this.WindowState = (isMinimized) ? FormWindowState.Normal : FormWindowState.Minimized;
    }

    // Show/Hide window and tray icon to match window state.
    private void SetMinimizeState(object sender, EventArgs e)
    {    
        bool isMinimized = this.WindowState == FormWindowState.Minimized;

        this.ShowInTaskbar = !isMinimized;           
        systemTrayIcon.Visible = isMinimized;
        if (isMinimized) systemTrayIcon.ShowBalloonTip(500, "Application", "Application minimized to tray.", ToolTipIcon.Info);
    }

Why am I getting tree conflicts in Subversion?

Until today, for since at least 3 months ago, I regularly encountered hundreds of tree conflicts when attempting to merge a branch back into the trunk (using TortoiseSVN 1.11). Whether rebased or not, BTW. I've been using TortoiseSVN since its v1, back in 2004, and I used to reintegrate branches all the time. Something must have happened recently I suppose?

So today I ran this simple experiment, and I found what was creating these crazy conflicts:

  1. I forked off the trunk @393;
  2. I modified tens of files randomly, as well as creating new ones;
  3. I committed. Now @395 (a colleague forked off at 394 to perform his own stuff).
  4. Then I tried to reintegrate the branch back into the trunk, test only; following TortoiseSVN's recommendation in the wizard: "to merge all revisions (reintegrate), leave that box empty". To achieve this, I right-clicked onto the trunk folder, and chose "TortoiseSVN > Merge, from /path/to/branch", and I left the rev range empty, as advised on the dialog.

Discussion: (see attachment)

all revisions... of what? Little did I know that the client must have been referring to "all revisions of the target! (trunk)", as, in the process of reintegrating that branch, I saw the mention "Merging revisions 1-HEAD"! OMG. Poor Devil, you're falling to your death here. That branch was born @393, can't you read its birth certificate, for God's sake? this is why so many conflicts occurred: SVN-cli is going on a foolish spree from revision 1

Resolution:

  1. Contrarily to what's advised by the wiz, do specify a range, that covers ALL revisions of...the branch's life! therefore, 394-HEAD;
  2. now run that merge test again, and get a cigar. (see second attachment).

Moral: I can't comprehend why they still haven't fixed that bug, because it is one, I'm sorry. I should take the time to report this with them.

TLS 1.2 not working in cURL

TLS 1.1 and TLS 1.2 are supported since OpenSSL 1.0.1

Forcing TLS 1.1 and 1.2 are only supported since curl 7.34.0

You should consider an upgrade.

Detect Windows version in .net

System.Environment.OSVersion has the information you need for distinguishing most Windows OS major releases, but not all. It consists of three components which map to the following Windows versions:

+------------------------------------------------------------------------------+
|                    |   PlatformID    |   Major version   |   Minor version   |
+------------------------------------------------------------------------------+
| Windows 95         |  Win32Windows   |         4         |          0        |
| Windows 98         |  Win32Windows   |         4         |         10        |
| Windows Me         |  Win32Windows   |         4         |         90        |
| Windows NT 4.0     |  Win32NT        |         4         |          0        |
| Windows 2000       |  Win32NT        |         5         |          0        |
| Windows XP         |  Win32NT        |         5         |          1        |
| Windows 2003       |  Win32NT        |         5         |          2        |
| Windows Vista      |  Win32NT        |         6         |          0        |
| Windows 2008       |  Win32NT        |         6         |          0        |
| Windows 7          |  Win32NT        |         6         |          1        |
| Windows 2008 R2    |  Win32NT        |         6         |          1        |
| Windows 8          |  Win32NT        |         6         |          2        |
| Windows 8.1        |  Win32NT        |         6         |          3        |
+------------------------------------------------------------------------------+
| Windows 10         |  Win32NT        |        10         |          0        |
+------------------------------------------------------------------------------+

For a library that allows you to get a more complete view of the exact release of Windows that the current execution environment is running in, check out this library.

Important note: if your executable assembly manifest doesn't explicitly state that your exe assembly is compatible with Windows 8.1 and Windows 10.0, System.Environment.OSVersion will return Windows 8 version, which is 6.2, instead of 6.3 and 10.0! Source: here.

How to ignore deprecation warnings in Python

I found the cleanest way to do this (especially on windows) is by adding the following to C:\Python26\Lib\site-packages\sitecustomize.py:

import warnings
warnings.filterwarnings("ignore", category=DeprecationWarning)

Note that I had to create this file. Of course, change the path to python if yours is different.

How to add native library to "java.library.path" with Eclipse launch (instead of overriding it)

SWT puts the necessary native DLLs into a JAR. Search for "org.eclipse.swt.win32.win32.x86_3.4.1.v3449c.jar" for an example.

The DLLs must be in the root of the JAR, the JAR must be signed and the DLL must appear with checksum in the META-INF/MANIFEST.MF for the VM to pick them up.

Datanode process not running in Hadoop

Try this

  1. stop-all.sh
  2. vi hdfs-site.xml
  3. change the value given for property dfs.data.dir
  4. format namenode
  5. start-all.sh

Match line break with regular expression

You could search for:

<li><a href="#">[^\n]+

And replace with:

$0</a>

Where $0 is the whole match. The exact semantics will depend on the language are you using though.

WARNING: You should avoid parsing HTML with regex. Here's why.

How to stretch in width a WPF user control to its window?

Is the Canvas crucial in your window? If not, try removing it and keep the Grid as the main panel. Canvas has no size unless specified, while a Grid normally takes up all available space. Inside the Canvas, the Grid will have no available space.

What is the difference between Digest and Basic Authentication?

Let us see the difference between the two HTTP authentication using Wireshark (Tool to analyse packets sent or received) .

1. Http Basic Authentication

Basic

As soon as the client types in the correct username:password,as requested by the Web-server, the Web-Server checks in the Database if the credentials are correct and gives the access to the resource .

Here is how the packets are sent and received :

enter image description here In the first packet the Client fill the credentials using the POST method at the resource - lab/webapp/basicauth .In return the server replies back with http response code 200 ok ,i.e, the username:password were correct .

Detail of HTTP packet

Now , In the Authorization header it shows that it is Basic Authorization followed by some random string .This String is the encoded (Base64) version of the credentials admin:aadd (including colon ) .

2 . Http Digest Authentication(rfc 2069)

So far we have seen that the Basic Authentication sends username:password in plaintext over the network .But the Digest Auth sends a HASH of the Password using Hash algorithm.

Here are packets showing the requests made by the client and response from the server .

Digest

As soon as the client types the credentials requested by the server , the Password is converted to a response using an algorithm and then is sent to the server , If the server Database has same response as given by the client the server gives the access to the resource , otherwise a 401 error .

Detailed digest auth packet In the above Authorization , the response string is calculated using the values of Username,Realm,Password,http-method,URI and Nonce as shown in the image :

Response algorithm (colons are included)

Hence , we can see that the Digest Authentication is more Secure as it involve Hashing (MD5 encryption) , So the packet sniffer tools cannot sniff the Password although in Basic Auth the exact Password was shown on Wireshark.

Force flex item to span full row width

When you want a flex item to occupy an entire row, set it to width: 100% or flex-basis: 100%, and enable wrap on the container.

The item now consumes all available space. Siblings are forced on to other rows.

_x000D_
_x000D_ 
.parent {
  display: flex;
  flex-wrap: wrap;
}

#range, #text {
  flex: 1;
}

.error {
  flex: 0 0 100%; /* flex-grow, flex-shrink, flex-basis */
  border: 1px dashed black;
}
_x000D_ 
<div class="parent">
  <input type="range" id="range">
  <input type="text" id="text">
  <label class="error">Error message (takes full width)</label>
</div>
_x000D_
_x000D_
_x000D_

More info: The initial value of the flex-wrap property is nowrap, which means that all items will line up in a row. MDN

Truncate Decimal number not Round Off

Try this 

double d = 2.22912312515;
int demention = 3;
double truncate = Math.Truncate(d) + Math.Truncate((d - Math.Truncate(d)) * Math.Pow(10.0, demention)) / Math.Pow(10.0, demention);

Is it possible to insert multiple rows at a time in an SQLite database?

According to this page it is not supported:

  • 2007-12-03 : Multi-row INSERT a.k.a. compound INSERT not supported. 
  INSERT INTO table (col1, col2) VALUES 
      ('row1col1', 'row1col2'), ('row2col1', 'row2col2'), ...

Actually, according to the SQL92 standard, a VALUES expression should be able to stand on itself. For example, the following should return a one-column table with three rows: VALUES 'john', 'mary', 'paul';

As of version 3.7.11 SQLite does support multi-row-insert. Richard Hipp comments:

"The new multi-valued insert is merely syntactic suger (sic) for the compound insert. There is no performance advantage one way or the other."

How do you merge two Git repositories?

To merge a A within B:

1) In the project A

git fast-export --all --date-order > /tmp/ProjectAExport

2) In the project B

git checkout -b projectA
git fast-import --force < /tmp/ProjectAExport

In this branch do all operations you need to do and commit them.

C) Then back to the master and a classical merge between the two branches:

git checkout master
git merge projectA

MySQL Select all columns from one table and some from another table

I need more information really but it will be along the lines of..

SELECT table1.*, table2.col1, table2.col3 FROM table1 JOIN table2 USING(id)

nodejs - first argument must be a string or Buffer - when using response.write with http.request

Well, obviously you are trying to send something which is not a string or buffer. :) It works with console, because console accepts anything. Simple example:

var obj = { test : "test" };
console.log( obj ); // works
res.write( obj ); // fails

One way to convert anything to string is to do that:

res.write( "" + obj );

whenever you are trying to send something. The other way is to call .toString() method:

res.write( obj.toString( ) );

Note that it still might not be what you are looking for. You should always pass strings/buffers to .write without such tricks.

As a side note: I assume that request is a asynchronous operation. If that's the case, then res.end(); will be called before any writing, i.e. any writing will fail anyway ( because the connection will be closed at that point ). Move that line into the handler:

request({
    uri: 'http://www.google.com',
    method: 'GET',
    maxRedirects:3
}, function(error, response, body) {
    if (!error) {
        res.write(response.statusCode);
    } else {
        //response.end(error);
        res.write(error);
    }
    res.end( );
});

Incrementing in C++ - When to use x++ or ++x?

You explained the difference correctly. It just depends on if you want x to increment before every run through a loop, or after that. It depends on your program logic, what is appropriate.

An important difference when dealing with STL-Iterators (which also implement these operators) is, that it++ creates a copy of the object the iterator points to, then increments, and then returns the copy. ++it on the other hand does the increment first and then returns a reference to the object the iterator now points to. This is mostly just relevant when every bit of performance counts or when you implement your own STL-iterator.

Edit: fixed the mixup of prefix and suffix notation

The 'packages' element is not declared

You can also find a copy of the nuspec.xsd here as it seems to no longer be available:

https://gist.github.com/sharwell/6131243

What is the best way to find the users home directory in Java?

Others have answered the question before me but a useful program to print out all available properties is: 

for (Map.Entry<?,?> e : System.getProperties().entrySet()) {
    System.out.println(String.format("%s = %s", e.getKey(), e.getValue())); 
}

Pandas: sum DataFrame rows for given columns

Following syntax helped me when I have columns in sequence 

awards_frame.values[:,1:4].sum(axis =1)

How to embed image or picture in jupyter notebook, either from a local machine or from a web resource?

Insert the image directly in the Jupyter notebook.

Note: You should have a local copy of the image on your computer

You can insert the image in the Jupyter notebook itself. This way you don't need to keep the image separately in the folder.

Steps:

  1. Convert the cell to markdown by:

    • pressing M on the selected cell
      OR
    • From menu bar, Cell > Cell Type > Markdown.
      (Note: It's important to convert the cell to Markdown, otherwise the "Insert Image" option in Step 2 will not be active)

  2. Now go to menu bar and select Edit -> Insert Image.

  3. Select image from your disk and upload.

  4. Press Ctrl+Enter or Shift+Enter.

This will make the image as part of the notebook and you don't need to upload in the directory or Github. I feel this looks more clean and not prone to broken URL issue.

Android Studio emulator does not come with Play Store for API 23

Wanted to comment on the last answer, but without login it’s only possible to make an answer:

To get rid of the "read only error" just stop the device immediately after it’s ready. My script looks as follows:

#!/bin/bash 
~/bin/AndroidSdk/tools/emulator @Nexus_6P_API_23 -no-boot-anim &
adb wait-for-device
adb shell stop
adb remount
adb push GmsCore.apk /system/priv-app
adb push GoogleServicesFramework.apk /system/priv-app
adb push GoogleLoginService.apk /system/priv-app
adb push Phonesky.apk /system/priv-app
adb shell start

Use of "this" keyword in formal parameters for static methods in C#

Scott Gu's quoted blog post explains it nicely.

For me, the answer to the question is in the following statement in that post:

Note how the static method above has a "this" keyword before the first parameter argument of type string. This tells the compiler that this particular Extension Method should be added to objects of type "string". Within the IsValidEmailAddress() method implementation I can then access all of the public properties/methods/events of the actual string instance that the method is being called on, and return true/false depending on whether it is a valid email or not.

Get dates from a week number in T-SQL

This works for me:

select 
    convert(varchar(50), dateadd(dd, - datepart(dw, DATECOL) + 1, DATECOL), 101),
    convert(varchar(50), dateadd(dd, - datepart(dw, DATECOL) + 7, DATECOL), 101)

Subtract two dates in SQL and get days of the result

How about 

Select I.Fee
From Item I
WHERE  (days(GETDATE()) - days(I.DateCreated) < 365)

How do you determine what technology a website is built on?

You can use domaintools.com to lookup the server information for a website and narrow down to whether it's open source / Microsoft:

http://whois.domaintools.com/stackoverflow.com

And after that it's a matter of looking in the footer for tip-offs such as "Powered by WordPress" or "vBulletin" etc.

Parse an HTML string with JS

EDIT: The solution below is only for HTML "fragments" since html,head and body are removed. I guess the solution for this question is DOMParser's parseFromString() method.

For HTML fragments, the solutions listed here works for most HTML, however for certain cases it won't work.

For example try parsing <td>Test</td>. This one won't work on the div.innerHTML solution nor DOMParser.prototype.parseFromString nor range.createContextualFragment solution. The td tag goes missing and only the text remains.

Only jQuery handles that case well.

So the future solution (MS Edge 13+) is to use template tag:

function parseHTML(html) {
    var t = document.createElement('template');
    t.innerHTML = html;
    return t.content.cloneNode(true);
}

var documentFragment = parseHTML('<td>Test</td>');

For older browsers I have extracted jQuery's parseHTML() method into an independent gist - https://gist.github.com/Munawwar/6e6362dbdf77c7865a99

How to correctly implement custom iterators and const_iterators?

There are plenty of good answers but I created a template header I use that is quite concise and easy to use.

To add an iterator to your class it is only necessary to write a small class to represent the state of the iterator with 7 small functions, of which 2 are optional:

#include <iostream>
#include <vector>
#include "iterator_tpl.h"

struct myClass {
  std::vector<float> vec;

  // Add some sane typedefs for STL compliance:
  STL_TYPEDEFS(float);

  struct it_state {
    int pos;
    inline void begin(const myClass* ref) { pos = 0; }
    inline void next(const myClass* ref) { ++pos; }
    inline void end(const myClass* ref) { pos = ref->vec.size(); }
    inline float& get(myClass* ref) { return ref->vec[pos]; }
    inline bool cmp(const it_state& s) const { return pos != s.pos; }

    // Optional to allow operator--() and reverse iterators:
    inline void prev(const myClass* ref) { --pos; }
    // Optional to allow `const_iterator`:
    inline const float& get(const myClass* ref) const { return ref->vec[pos]; }
  };
  // Declare typedef ... iterator;, begin() and end() functions:
  SETUP_ITERATORS(myClass, float&, it_state);
  // Declare typedef ... reverse_iterator;, rbegin() and rend() functions:
  SETUP_REVERSE_ITERATORS(myClass, float&, it_state);
};

Then you can use it as you would expect from an STL iterator:

int main() {
  myClass c1;
  c1.vec.push_back(1.0);
  c1.vec.push_back(2.0);
  c1.vec.push_back(3.0);

  std::cout << "iterator:" << std::endl;
  for (float& val : c1) {
    std::cout << val << " "; // 1.0 2.0 3.0
  }

  std::cout << "reverse iterator:" << std::endl;
  for (auto it = c1.rbegin(); it != c1.rend(); ++it) {
    std::cout << *it << " "; // 3.0 2.0 1.0
  }
}

I hope it helps.

What is the best way to convert seconds into (Hour:Minutes:Seconds:Milliseconds) time?

For .Net <= 4.0 Use the TimeSpan class.

TimeSpan t = TimeSpan.FromSeconds( secs );

string answer = string.Format("{0:D2}h:{1:D2}m:{2:D2}s:{3:D3}ms", 
                t.Hours, 
                t.Minutes, 
                t.Seconds, 
                t.Milliseconds);

(As noted by Inder Kumar Rathore) For .NET > 4.0 you can use

TimeSpan time = TimeSpan.FromSeconds(seconds);

//here backslash is must to tell that colon is
//not the part of format, it just a character that we want in output
string str = time .ToString(@"hh\:mm\:ss\:fff");

(From Nick Molyneux) Ensure that seconds is less than TimeSpan.MaxValue.TotalSeconds to avoid an exception.

Creating multiple log files of different content with log4j

Perhaps something like this?

<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
 <!-- general application log -->
 <appender name="MainLogFile" class="org.apache.log4j.FileAppender">
  <param name="File" value="server.log" />
  <param name="Threshold" value="INFO" />
  <layout class="org.apache.log4j.PatternLayout">
   <param name="ConversionPattern" value="%-5p %t [%-40.40c] %x - %m%n"/>
  </layout>
 </appender> 
 <!-- additional fooSystem logging -->
 <appender name="FooLogFile" class="org.apache.log4j.FileAppender">
  <param name="File" value="foo.log" />
  <layout class="org.apache.log4j.PatternLayout">
   <param name="ConversionPattern" value="%-5p %t [%-40.40c] %x - %m%n"/>
  </layout>
 </appender>
 <!-- foo logging -->
 <logger name="com.example.foo">
  <level value="DEBUG"/>
  <appender-ref ref="FooLogFile"/>
 </logger>
 <!-- default logging -->
 <root>
  <level value="INFO"/>
  <appender-ref ref="MainLogFile"/>
 </root>
</log4j:configuration>

Thus, all info messages are written to server.log; by contrast, foo.log contains only com.example.foo messages, including debug-level messages.

How to properly use the "choices" field option in Django

$ pip install django-better-choices

For those who are interested, I have created django-better-choices library, that provides a nice interface to work with Django choices for Python 3.7+. It supports custom parameters, lots of useful features and is very IDE friendly.

You can define your choices as a class:

from django_better_choices import Choices


class PAGE_STATUS(Choices):
    CREATED = 'Created'
    PENDING = Choices.Value('Pending', help_text='This set status to pending')
    ON_HOLD = Choices.Value('On Hold', value='custom_on_hold')

    VALID = Choices.Subset('CREATED', 'ON_HOLD')

    class INTERNAL_STATUS(Choices):
        REVIEW = 'On Review'

    @classmethod
    def get_help_text(cls):
        return tuple(
            value.help_text
            for value in cls.values()
            if hasattr(value, 'help_text')
        )

Then do the following operations and much much more:

print( PAGE_STATUS.CREATED )                # 'created'
print( PAGE_STATUS.ON_HOLD )                # 'custom_on_hold'
print( PAGE_STATUS.PENDING.display )        # 'Pending'
print( PAGE_STATUS.PENDING.help_text )      # 'This set status to pending'

'custom_on_hold' in PAGE_STATUS.VALID       # True
PAGE_STATUS.CREATED in PAGE_STATUS.VALID    # True

PAGE_STATUS.extract('CREATED', 'ON_HOLD')   # ~= PAGE_STATUS.VALID

for value, display in PAGE_STATUS:
    print( value, display )

PAGE_STATUS.get_help_text()
PAGE_STATUS.VALID.get_help_text()

And of course, it is fully supported by Django and Django Migrations:

class Page(models.Model):
    status = models.CharField(choices=PAGE_STATUS, default=PAGE_STATUS.CREATED)

Full documentation here: https://pypi.org/project/django-better-choices/

How can I make space between two buttons in same div?

You can use spacing for Bootstrap and no need for any additional CSS. Just add the classes to your buttons. This is for version 4.

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

From jQuery Docs:

const height = $(window).height();
const scrollTop = $(window).scrollTop();

http://api.jquery.com/scrollTop/
http://api.jquery.com/height/

Map.Entry: How to use it?

Hash-Map stores the (key,value) pair as the Map.Entry Type.As you know that Hash-Map uses Linked Hash-Map(In case Collision occurs). Therefore each Node in the Bucket of Hash-Map is of Type Map.Entry. So whenever you iterate through the Hash-Map you will get Nodes of Type Map.Entry.

Now in your example when you are iterating through the Hash-Map, you will get Map.Entry Type(Which is Interface), To get the Key and Value from this Map.Entry Node Object, interface provided methods like getValue(), getKey() etc. So as per the code, In your Object you are adding all operators JButtons viz (+,-,/,*,=).

Android, landscape only orientation?

Add this android:screenOrientation="landscape" to your <activity> tag in the manifest for the specific activity that you want to be in landscape.

Edit:

To toggle the orientation from the Activity code, call setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE) other parameters can be found in the Android docs for ActivityInfo.

PHP "php://input" vs $_POST

The reason is that php://input returns all the raw data after the HTTP-headers of the request, regardless of the content type.

The PHP superglobal $_POST, only is supposed to wrap data that is either

  • application/x-www-form-urlencoded (standard content type for simple form-posts) or
  • multipart/form-data (mostly used for file uploads)

This is because these are the only content types that must be supported by user agents. So the server and PHP traditionally don't expect to receive any other content type (which doesn't mean they couldn't).

So, if you simply POST a good old HTML form, the request looks something like this:

POST /page.php HTTP/1.1

key1=value1&key2=value2&key3=value3

But if you are working with Ajax a lot, this probaby also includes exchanging more complex data with types (string, int, bool) and structures (arrays, objects), so in most cases JSON is the best choice. But a request with a JSON-payload would look something like this:

POST /page.php HTTP/1.1

{"key1":"value1","key2":"value2","key3":"value3"}

The content would now be application/json (or at least none of the above mentioned), so PHP's $_POST-wrapper doesn't know how to handle that (yet).

The data is still there, you just can't access it through the wrapper. So you need to fetch it yourself in raw format with file_get_contents('php://input') (as long as it's not multipart/form-data-encoded).

This is also how you would access XML-data or any other non-standard content type.

How to create an AVD for Android 4.0

I had a similar problem but using IntelliJ IDEA rather than Eclipse. I already had the ARM EABI installed, but I still got the error.

For IntelliJ IDEA, it appears you also have to create an AVB first before running the emulator, so to do this you must just go into Android SDK Manager and create a new AVB. This should solve your problem... Please make sure you have followed the above answer to include the ARM before following these steps.

How to check if all inputs are not empty with jQuery

You can do it.here is code

<!DOCTYPE html>
<html lang="en">
 <head>
 <meta charset="UTF-8">
 <title></title>
 <script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<style>
select,textarea,input[type="text"],input[type="password"],input[type="datetime"],input[type="datetime-local"],input[type="date"],input[type="month"],input[type="time"],input[type="week"],input[type="number"],input[type="email"],input[type="url"],input[type="search"],input[type="tel"],input[type="color"],.uneditable-input{display:inline-block;height:20px;padding:4px;margin-bottom:9px;font-size:13px;line-height:18px;color:#555555;}
textarea{height:auto;}
select,textarea,input[type="text"],input[type="password"],input[type="datetime"],input[type="datetime-local"],input[type="date"],input[type="month"],input[type="time"],input[type="week"],input[type="number"],input[type="email"],input[type="url"],input[type="search"],input[type="tel"],input[type="color"],.uneditable-input{background-color:#ffffff;border:1px solid #cccccc;-webkit-border-radius:3px;-moz-border-radius:3px;border-radius:3px;-webkit-box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.075);-moz-box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.075);box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.075);-webkit-transition:border linear 0.2s,box-shadow linear 0.2s;-moz-transition:border linear 0.2s,box-shadow linear 0.2s;-ms-transition:border linear 0.2s,box-shadow linear 0.2s;-o-transition:border linear 0.2s,box-shadow linear 0.2s;transition:border linear 0.2s,box-shadow linear 0.2s;}textarea:focus,input[type="text"]:focus,input[type="password"]:focus,input[type="datetime"]:focus,input[type="datetime-local"]:focus,input[type="date"]:focus,input[type="month"]:focus,input[type="time"]:focus,input[type="week"]:focus,input[type="number"]:focus,input[type="email"]:focus,input[type="url"]:focus,input[type="search"]:focus,input[type="tel"]:focus,input[type="color"]:focus,.uneditable-input:focus{border-color:rgba(82, 168, 236, 0.8);outline:0;outline:thin dotted \9;-webkit-box-shadow:inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(82,168,236,.6);-moz-box-shadow:inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(82,168,236,.6);box-shadow:inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(82,168,236,.6);height: 20px;}
select,input[type="radio"],input[type="checkbox"]{margin:3px 0;*margin-top:0;line-height:normal;cursor:pointer;}
select,input[type="submit"],input[type="reset"],input[type="button"],input[type="radio"],input[type="checkbox"]{width:auto;}
.uneditable-textarea{width:auto;height:auto;}
#country{height: 30px;}
.highlight
{
    border: 1px solid red !important;
}
</style>
<script>
function test()
{
var isFormValid = true;

$(".bs-example input").each(function(){
    if ($.trim($(this).val()).length == 0){
        $(this).addClass("highlight");
        isFormValid = false;
        $(this).focus();
    }
    else{
        $(this).removeClass("highlight");
    }
});

if (!isFormValid) { 
    alert("Please fill in all the required fields (indicated by *)");
}

  return isFormValid;
 }  
 </script>
</head>
 <body>
 <div class="bs-example">
<form onsubmit="return test()">
    <div class="form-group">
        <label for="inputEmail">Email</label>
        <input type="text" class="form-control" id="inputEmail" placeholder="Email">
    </div>
    <div class="form-group">
        <label for="inputPassword">Password</label>
        <input type="password" class="form-control" id="inputPassword" placeholder="Password">
    </div>
    <button type="submit" class="btn btn-primary">Login</button>
   </form>
  </div>
 </body>
 </html>

Powershell Active Directory - Limiting my get-aduser search to a specific OU [and sub OUs]

If I understand you correctly, you need to use -SearchBase:

Get-ADUser -SearchBase "OU=Accounts,OU=RootOU,DC=ChildDomain,DC=RootDomain,DC=com" -Filter *

Note that Get-ADUser defaults to using

 -SearchScope Subtree

so you don't need to specify it. It's this that gives you all sub-OUs (and sub-sub-OUs, etc.).

pypi UserWarning: Unknown distribution option: 'install_requires'

python setup.py uses distutils which doesn't support install_requires. setuptools does, also distribute (its successor), and pip (which uses either) do. But you actually have to use them. I.e. call setuptools through the easy_install command or pip install.

Another way is to import setup from setuptools in your setup.py, but this not standard and makes everybody wanting to use your package have to have setuptools installed.

How do you connect localhost in the Android emulator?

Thanks, @lampShaded for your answer.

In your API/URL directly use http://10.0.2.2:[your port]/ and under emulator setting add the proxy address as 10.0.2.2 with the port number. For more, you can visit: https://developer.android.com/studio/run/emulator-networking.html

enter image description here

How to get a variable name as a string in PHP?

I have this:

  debug_echo(array('$query'=>$query, '$nrUsers'=>$nrUsers, '$hdr'=>$hdr));

I would prefer this:

  debug_echo($query, $nrUsers, $hdr);

The existing function displays a yellow box with a red outline and shows each variable by name and value. The array solution works but is a little convoluted to type when it is needed.

That's my use case and yes, it does have to do with debugging. I agree with those who question its use otherwise.

SQL query for extracting year from a date

just pass the columnName as parameter of YEAR

SELECT YEAR(ASOFDATE) from PSASOFDATE;

another is to use DATE_FORMAT

SELECT DATE_FORMAT(ASOFDATE, '%Y') from PSASOFDATE;

UPDATE 1

I bet the value is varchar with the format MM/dd/YYYY, it that's the case,

SELECT YEAR(STR_TO_DATE('11/15/2012', '%m/%d/%Y'));

LAST RESORT if all the queries fail

use SUBSTRING

SELECT SUBSTRING('11/15/2012', 7, 4)

Returning pointer from a function

It is not allocating memory at assignment of value 12 to integer pointer. Therefore it crashes, because it's not finding any memory.

You can try this:

#include<stdio.h>
#include<stdlib.h>
int *fun();

int main()
{
    int *ptr;
    ptr=fun();
    printf("\n\t\t%d\n",*ptr);
}

int *fun()
{
    int ptr;
    ptr=12;
    return(&ptr);
}

Apache Spark: The number of cores vs. the number of executors

Spark Dynamic allocation gives flexibility and allocates resources dynamically. In this number of min and max executors can be given. Also the number of executors that has to be launched at the starting of the application can also be given.

Read below on the same:

http://spark.apache.org/docs/latest/configuration.html#dynamic-allocation

Composer: The requested PHP extension ext-intl * is missing from your system

I encountered this using it in Mac, resolved it by using --ignore-platform-reqs option.

composer install --ignore-platform-reqs

Function to calculate distance between two coordinates

Great-circle distance - From chord length

Here's an elegant solution applying the strategy design pattern; I hope it's readable enough.

TwoPointsDistanceCalculatorStrategy.js:

module.exports = () =>

class TwoPointsDistanceCalculatorStrategy {

    constructor() {}

    calculateDistance({ point1Coordinates, point2Coordinates }) {}
};

GreatCircleTwoPointsDistanceCalculatorStrategy.js:

module.exports = ({ TwoPointsDistanceCalculatorStrategy }) =>

class GreatCircleTwoPointsDistanceCalculatorStrategy extends TwoPointsDistanceCalculatorStrategy {

    constructor() {
        super();
    }

    /**
     * Following the algorithm documented here: 
     * https://en.wikipedia.org/wiki/Great-circle_distance#Computational_formulas
     * 
     * @param {object} inputs
     * @param {array} inputs.point1Coordinates
     * @param {array} inputs.point2Coordinates
     * 
     * @returns {decimal} distance in kelometers
     */
    calculateDistance({ point1Coordinates, point2Coordinates }) {

        const convertDegreesToRadians = require('../convert-degrees-to-radians');
        const EARTH_RADIUS = 6371;   // in kelometers

        const [lat1 = 0, lon1 = 0] = point1Coordinates;
        const [lat2 = 0, lon2 = 0] = point2Coordinates;

        const radianLat1 = convertDegreesToRadians({ degrees: lat1 });
        const radianLon1 = convertDegreesToRadians({ degrees: lon1 });
        const radianLat2 = convertDegreesToRadians({ degrees: lat2 });
        const radianLon2 = convertDegreesToRadians({ degrees: lon2 });

        const centralAngle = _computeCentralAngle({ 
            lat1: radianLat1, lon1: radianLon1, 
            lat2: radianLat2, lon2: radianLon2, 
        });

        const distance = EARTH_RADIUS * centralAngle;

        return distance;
    }
};


/**
 * 
 * @param {object} inputs
 * @param {decimal} inputs.lat1
 * @param {decimal} inputs.lon1
 * @param {decimal} inputs.lat2
 * @param {decimal} inputs.lon2
 * 
 * @returns {decimal} centralAngle
 */
function _computeCentralAngle({ lat1, lon1, lat2, lon2 }) {

    const chordLength = _computeChordLength({ lat1, lon1, lat2, lon2 });
    const centralAngle = 2 * Math.asin(chordLength / 2);

    return centralAngle;
}


/**
 * 
 * @param {object} inputs
 * @param {decimal} inputs.lat1
 * @param {decimal} inputs.lon1
 * @param {decimal} inputs.lat2
 * @param {decimal} inputs.lon2
 * 
 * @returns {decimal} chordLength
 */
function _computeChordLength({ lat1, lon1, lat2, lon2 }) {

    const { sin, cos, pow, sqrt } = Math;

    const ?X = cos(lat2) * cos(lon2) - cos(lat1) * cos(lon1);
    const ?Y = cos(lat2) * sin(lon2) - cos(lat1) * sin(lon1);
    const ?Z = sin(lat2) - sin(lat1);

    const ?XSquare = pow(?X, 2);
    const ?YSquare = pow(?Y, 2);
    const ?ZSquare = pow(?Z, 2);

    const chordLength = sqrt(?XSquare + ?YSquare + ?ZSquare);

    return chordLength;
}

convert-degrees-to-radians.js:

module.exports = function convertDegreesToRadians({ degrees }) {

    return degrees * Math.PI / 180;
};

This's following the Great-circle distance - From chord length, documented here.

Left join only selected columns in R with the merge() function

Nothing elegant but this could be another satisfactory answer.

merge(x = DF1, y = DF2, by = "Client", all.x=TRUE)[,c("Client","LO","CON")]

This will be useful especially when you don't need the keys that were used to join the tables in your results.

Is there any difference between a GUID and a UUID?

GUID is Microsoft's implementation of the UUID standard.

Per Wikipedia:

The term GUID usually refers to Microsoft's implementation of the Universally Unique Identifier (UUID) standard.

An updated quote from that same Wikipedia article:

RFC 4122 itself states that UUIDs "are also known as GUIDs". All this suggests that "GUID", while originally referring to a variant of UUID used by Microsoft, has become simply an alternative name for UUID…

moving changed files to another branch for check-in

A soft git reset will put committed changes back into your index. Next, checkout the branch you had intended to commit on. Then git commit with a new commit message.

  1. git reset --soft <commit>

  2. git checkout <branch>

  3. git commit -m "Commit message goes here"

From git docs:

git reset [<mode>] [<commit>] This form resets the current branch head to and possibly updates the index (resetting it to the tree of ) and the working tree depending on . If is omitted, defaults to --mixed. The must be one of the following:

--soft Does not touch the index file or the working tree at all (but resets the head to , just like all modes do). This leaves all your changed files "Changes to be committed", as git status would put it.

MySQL show status - active or total connections?

In order to check the maximum allowed connections, you can run the following query:

SHOW VARIABLES LIKE "max_connections";

To check the number of active connections, you can run the following query:

SHOW VARIABLES LIKE "max_used_connections";

Hope it helps.

Twitter Bootstrap inline input with dropdown

Daniel Farrell's Bootstrap Combobox does the job perfectly. Here's an example from his GitHub repository.

_x000D_
_x000D_ 
$(document).ready(function(){_x000D_
  $('.combobox').combobox();_x000D_
  _x000D_
  // bonus: add a placeholder_x000D_
  $('.combobox').attr('placeholder', 'For example, start typing "Pennsylvania"');_x000D_
});
_x000D_ 
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css">_x000D_
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-combobox/1.1.8/css/bootstrap-combobox.min.css">_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-combobox/1.1.8/js/bootstrap-combobox.min.js"></script>_x000D_
_x000D_
<select class="combobox form-control">_x000D_
  <option></option>_x000D_
  <option value="PA">Pennsylvania</option>_x000D_
  <option value="CT">Connecticut</option>_x000D_
  <option value="NY">New York</option>_x000D_
  <option value="MD">Maryland</option>_x000D_
  <option value="VA">Virginia</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

As an added bonus, I've included a placeholder in script since applying it to the markup does not hold.

How to center a subview of UIView

enter image description here

Set this autoresizing mask to your inner view.

how to convert a string to an array in php

With explode function of php

$array=explode(" ",$str);

This is a quick example for you http://codepad.org/Pbg4n76i

Semaphore vs. Monitors - what's the difference?

Following explanation actually explains how wait() and signal() of monitor differ from P and V of semaphore.

The wait() and signal() operations on condition variables in a monitor are similar to P and V operations on counting semaphores.

A wait statement can block a process's execution, while a signal statement can cause another process to be unblocked. However, there are some differences between them. When a process executes a P operation, it does not necessarily block that process because the counting semaphore may be greater than zero. In contrast, when a wait statement is executed, it always blocks the process. When a task executes a V operation on a semaphore, it either unblocks a task waiting on that semaphore or increments the semaphore counter if there is no task to unlock. On the other hand, if a process executes a signal statement when there is no other process to unblock, there is no effect on the condition variable. Another difference between semaphores and monitors is that users awaken by a V operation can resume execution without delay. Contrarily, users awaken by a signal operation are restarted only when the monitor is unlocked. In addition, a monitor solution is more structured than the one with semaphores because the data and procedures are encapsulated in a single module and that the mutual exclusion is provided automatically by the implementation.

Link: here for further reading. Hope it helps.

mysql said: Cannot connect: invalid settings. xampp

If you are facing this issue after changing password in phpmyadmin, paste the old password (passwd before change) in xampp\phpMyAdmin\config.inc.php :

$cfg['Servers'][$i]['password'] = '**old password here**';

Hope, it would work :)

How do I remove repeated elements from ArrayList?

The @jonathan-stafford solution is OK. But this don't preserve the list order.

If you want preserve the list order you have to use this:

public static <T> void removeDuplicate(List <T> list) {
Set <T> set = new HashSet <T>();
List <T> newList = new ArrayList <T>();
for (Iterator <T>iter = list.iterator();    iter.hasNext(); ) {
   Object element = iter.next();
   if (set.add((T) element))
      newList.add((T) element);
   }
   list.clear();
   list.addAll(newList);
}

It's only to complete the answer. Very good!

Assignment inside lambda expression in Python

If instead of flag = True we can do an import instead, then I think this meets the criteria:

>>> from itertools import count
>>> a = ['hello', '', 'world', '', '', '', 'bob']
>>> filter(lambda L, j=count(): L or not next(j), a)
['hello', '', 'world', 'bob']

Or maybe the filter is better written as:

>>> filter(lambda L, blank_count=count(1): L or next(blank_count) == 1, a)

Or, just for a simple boolean, without any imports:

filter(lambda L, use_blank=iter([True]): L or next(use_blank, False), a)

How to count the number of rows in excel with data?

 
  n = ThisWorkbook.Worksheets(1).Range("A:A").Cells.SpecialCells(xlCellTypeConstants).Count

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

Would I just override the drawRect method?

Yes:

- (void)drawRect:(CGRect)rect
{
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGContextAddEllipseInRect(ctx, rect);
    CGContextSetFillColor(ctx, CGColorGetComponents([[UIColor blueColor] CGColor]));
    CGContextFillPath(ctx);
}

Also, would it be okay to change the frame of that view within the class itself?

Ideally not, but you could.

Or do I need to change the frame from a different class?

I'd let the parent control that.

Press TAB and then ENTER key in Selenium WebDriver

 
WebElement webElement = driver.findElement(By.xpath(""));

//Enter the xpath or ID.

     webElement.sendKeys("");

//Input the string to pass.

     webElement.sendKeys(Keys.TAB);

//This will enter the string which you want to pass and will press "Tab" button .

Jquery Smooth Scroll To DIV - Using ID value from Link

Ids are meant to be unique, and never use an id that starts with a number, use data-attributes instead to set the target like so :

<div id="searchbycharacter">
    <a class="searchbychar" href="#" data-target="numeric">0-9 |</a> 
    <a class="searchbychar" href="#" data-target="A"> A |</a> 
    <a class="searchbychar" href="#" data-target="B"> B |</a> 
    <a class="searchbychar" href="#" data-target="C"> C |</a> 
    ... Untill Z
</div>

As for the jquery :

$(document).on('click','.searchbychar', function(event) {
    event.preventDefault();
    var target = "#" + this.getAttribute('data-target');
    $('html, body').animate({
        scrollTop: $(target).offset().top
    }, 2000);
});

How can I convert a string to a float in mysql?

It turns out I was just missing DECIMAL on the CAST() description:

DECIMAL[(M[,D])]

Converts a value to DECIMAL data type. The optional arguments M and D specify the precision (M specifies the total number of digits) and the scale (D specifies the number of digits after the decimal point) of the decimal value. The default precision is two digits after the decimal point.

Thus, the following query worked:

UPDATE table SET
latitude = CAST(old_latitude AS DECIMAL(10,6)),
longitude = CAST(old_longitude AS DECIMAL(10,6));

Setting default checkbox value in Objective-C?

Documentation on UISwitch says:

[mySwitch setOn:NO];

In Interface Builder, select your switch and in the Attributes inspector you'll find State which can be set to on or off.

Simple way to understand Encapsulation and Abstraction

Abstraction is hiding the information or providing only necessary details to the client.

e.g Car Brakes- You just know that pressing the pedals will stop the vehicle but you don't need to know how it works internally.

Advantage of Abstraction Tomorrow if brake implementation changes from drum brake to disk brake, as a client, you don't need to change(i.e your code will not change)

Encapsulation is binding the data and behaviors together in a single unit. Also it is a language mechanism for restricting access to some components(this can be achieved by access modifiers like private,protected etc.)

For e.g. Class has attributes(i.e data) and behaviors (i.e methods that operate on that data)

Number of days in particular month of particular year?

This worked fine for me.

This is a Sample Output

import java.util.*;

public class DaysInMonth { 

    public static void main(String args []) { 

        Scanner input = new Scanner(System.in); 
        System.out.print("Enter a year:"); 

        int year = input.nextInt(); //Moved here to get input after the question is asked 

        System.out.print("Enter a month:"); 
        int month = input.nextInt(); //Moved here to get input after the question is asked 

        int days = 0; //changed so that it just initializes the variable to zero
        boolean isLeapYear = (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0); 

        switch (month) { 
            case 1: 
                days = 31; 
                break; 
            case 2: 
                if (isLeapYear) 
                    days = 29; 
                else 
                    days = 28; 
                break; 
            case 3: 
                days = 31; 
                break; 
            case 4: 
                days = 30; 
                break; 
            case 5: 
                days = 31; 
                break; 
            case 6: 
                days = 30; 
                break; 
            case 7: 
                days = 31; 
                break; 
            case 8: 
                days = 31; 
                break; 
            case 9: 
                days = 30; 
                break; 
            case 10: 
                days = 31; 
                break; 
            case 11: 
                days = 30; 
                break; 
            case 12: 
                days = 31; 
                break; 
            default: 
                String response = "Have a Look at what you've done and try again";
                System.out.println(response); 
                System.exit(0); 
        } 

        String response = "There are " + days + " Days in Month " + month + " of Year " + year + ".\n"; 
        System.out.println(response); // new line to show the result to the screen. 
    } 
} //[email protected]

Removing multiple files from a Git repo that have already been deleted from disk

As mentioned

git add -u

stages the removed files for deletion, BUT ALSO modified files for update.

To unstage the modified files you can do

git reset HEAD <path>

if you like to keep your commits organized and clean.
NOTE: This could also unstage the deleted files, so careful with those wildcards.

Show "loading" animation on button click

If you are using ajax then (making it as simple as possible)

  1. Add your loading gif image to html and make it hidden (using style in html itself now, you can add it to separate CSS):

    <img src="path\to\loading\gif" id="img" style="display:none"/ >

  2. Show the image when button is clicked and hide it again on success function

    $('#buttonID').click(function(){
  $('#img').show(); //<----here
  $.ajax({
    ....
   success:function(result){
       $('#img').hide();  //<--- hide again
   }
}

Make sure you hide the image on ajax error callbacks too to make sure the gif hides even if the ajax fails.

When to use static keyword before global variables?

static renders variable local to the file which is generally a good thing, see for example this Wikipedia entry.

Setting environment variables on OS X

Here is a very simple way to do what you want. In my case, it was getting Gradle to work (for Android Studio).

  • Open up Terminal.

  • Run the following command:

    sudo nano /etc/paths or sudo vim /etc/paths

  • Enter your password, when prompted.

  • Go to the bottom of the file, and enter the path you wish to add.
  • Hit Control + X to quit.
  • Enter 'Y' to save the modified buffer.

  • Open a new terminal window then type:

    echo $PATH

You should see the new path appended to the end of the PATH.

I got these details from this post:

Add to the PATH on Mac OS X 10.8 Mountain Lion and up

org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'customerService' is defined

By reading your exception , It's sure that you forgot to autowire customerService

You should autowire your customerservice .

make following changes in your controller class

@Controller
public class CustomerController{

    @Autowired
    private Customerservice customerservice;
......other code......

}

Again your service implementation class

write 

@Service
public class CustomerServiceImpl implements CustomerService {
    @Autowired
    private CustomerDAO customerDAO;
......other code......

.....add transactional methods
}

If you are using hibernate make necessary changes in your applicationcontext xml file(configuration of session factory is needed).

you should autowire sessionFactory set method in your DAO mplementation

please find samle application context :

<?xml  version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:jee="http://www.springframework.org/schema/jee"
    xmlns:lang="http://www.springframework.org/schema/lang"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd
        http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:annotation-config />
    <context:component-scan base-package="com.sparkle" />
    <!-- Configures the @Controller programming model -->
    <mvc:annotation-driven />

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
            p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" p:order="0" />

    <bean id="messageSource"
        class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <property name="basename" value="classpath:messages" />
        <property name="defaultEncoding" value="UTF-8" />
    </bean>
    <!-- <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
        p:location="/WEB-INF/jdbc.properties" /> -->

     <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">         
        <list>
            <value>/WEB-INF/jdbc.properties</value>          

        </list>    
    </property>     
    </bean>




    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource"
        p:driverClassName="${jdbc.driverClassName}"
        p:url="${jdbc.databaseurl}" p:username="${jdbc.username}"
        p:password="${jdbc.password}" />


    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation">
            <value>classpath:hibernate.cfg.xml</value>
        </property>
        <property name="configurationClass">
            <value>org.hibernate.cfg.AnnotationConfiguration</value>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${jdbc.dialect}</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>

    <tx:annotation-driven />


   <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"
          p:sessionFactory-ref="sessionFactory"/>


</beans>

note that i am using jdbc.properties file for jdbc url and driver specification

Initialize class fields in constructor or at declaration?

My rules:

  1. Don't initialize with the default values in declaration (null, false, 0, 0.0…).
  2. Prefer initialization in declaration if you don't have a constructor parameter that changes the value of the field.
  3. If the value of the field changes because of a constructor parameter put the initialization in the constructors.
  4. Be consistent in your practice (the most important rule).

WebAPI Multiple Put/Post parameters

If you don't want to go ModelBinding way, you can use DTOs to do this for you. For example, create a POST action in DataLayer which accepts a complex type and send data from the BusinessLayer. You can do it in case of UI->API call.

Here are sample DTO. Assign a Teacher to a Student and Assign multiple papers/subject to the Student.

public class StudentCurriculumDTO
 {
     public StudentTeacherMapping StudentTeacherMapping { get; set; }
     public List<Paper> Paper { get; set; }
 }    
public class StudentTeacherMapping
 {
     public Guid StudentID { get; set; }
     public Guid TeacherId { get; set; }
 }

public class Paper
 {
     public Guid PaperID { get; set; }
     public string Status { get; set; }
 }

Then the action in the DataLayer can be created as:

[HttpPost]
[ActionName("MyActionName")]
public async Task<IHttpActionResult> InternalName(StudentCurriculumDTO studentData)
  {
     //Do whatever.... insert the data if nothing else!
  }

To call it from the BusinessLayer: 

using (HttpResponseMessage response = await client.PostAsJsonAsync("myendpoint_MyActionName", dataof_StudentCurriculumDTO)
  {
     //Do whatever.... get response if nothing else!
  }

Now this will still work if I wan to send data of multiple Student at once. Modify the MyAction like below. No need to write [FromBody], WebAPI2 takes the complex type [FromBody] by default. 

public async Task<IHttpActionResult> InternalName(List<StudentCurriculumDTO> studentData)

and then while calling it, pass a List<StudentCurriculumDTO> of data. 

using (HttpResponseMessage response = await client.PostAsJsonAsync("myendpoint_MyActionName", List<dataof_StudentCurriculumDTO>)

Git/GitHub can't push to master

This error occurs when you clone a repo using a call like:

git clone git://github.com/....git

This essentially sets you up as a pull-only user, who can't push up changes.

I fixed this by opening my repo's .git/config file and changing the line:

[remote "origin"]
    url = git://github.com/myusername/myrepo.git

to:

[remote "origin"]
    url = ssh+git://[email protected]/myusername/myrepo.git

This ssh+git protocol with the git user is the authentication mechanism preferred by Github.

The other answers mentioned here technically work, but they all seem to bypass ssh, requiring you to manually enter a password, which you probably don't want.

How to use OpenFileDialog to select a folder?

As a note for future users who would like to avoid using FolderBrowserDialog, Microsoft once released an API called the WindowsAPICodePack that had a helpful dialog called CommonOpenFileDialog, that could be set into a IsFolderPicker mode. The API is available from Microsoft as a NuGet package.

This is all I needed to install and use the CommonOpenFileDialog. (NuGet handled the dependencies)

Install-Package Microsoft.WindowsAPICodePack-Shell

For the include line:

using Microsoft.WindowsAPICodePack.Dialogs;

Usage:

CommonOpenFileDialog dialog = new CommonOpenFileDialog();
dialog.InitialDirectory = "C:\\Users";
dialog.IsFolderPicker = true;
if (dialog.ShowDialog() == CommonFileDialogResult.Ok)
{
    MessageBox.Show("You selected: " + dialog.FileName);
}

Printing Mongo query output to a file while in the mongo shell

Combining several conditions:

  • write mongo query in JS file and send it from terminal
  • switch/define a database programmatically
  • output all found records
  • cut initial output lines
  • save the output into JSON file

myScriptFile.js

// Switch current database to "mydatabase"
db = db.getSiblingDB('mydatabase');

// The mark for cutting initial output off
print("CUT_TO_HERE");

// Main output
// "toArray()" method allows to get all records
printjson( db.getCollection('jobs').find().toArray() );

Sending the query from terminal

-z key of sed allows treat output as a single multi-line string

$> mongo localhost --quiet myScriptFile.js | sed -z 's/^.*CUT_TO_HERE\n//' > output.json

How do I show/hide a UIBarButtonItem?

 
@IBDesignable class AttributedBarButtonItem: UIBarButtonItem {

    var isHidden: Bool = false {

        didSet {

            isEnabled = !isHidden
            tintColor = isHidden ? UIColor.clear : UIColor.black
        }
    }
}

And now simply change isHidden property.

How to use z-index in svg elements?

Move to front by transform:TranslateZ

Warning: Only works in FireFox

_x000D_
_x000D_ 
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 160 160" style="width:160px; height:160px;">
    <g style="transform-style: preserve-3d;">
        <g id="one" style="transform-style: preserve-3d;">
            <circle fill="green" cx="100" cy="105" r="20" style="transform:TranslateZ(1px);"></circle>
        </g>
        <g id="two" style="transform-style: preserve-3d;">
            <circle fill="orange" cx="100" cy="95" r="20"></circle>
        </g>
    </g>
</svg>
_x000D_
_x000D_
_x000D_

How many concurrent AJAX (XmlHttpRequest) requests are allowed in popular browsers?

The network results at Browserscope will give you both Connections per Hostname and Max Connections for popular browsers. The data is gathered by running tests on users "in the wild," so it will stay up to date.

A top-like utility for monitoring CUDA activity on a GPU

I created a batch file with the following code in a windows machine to monitor every second. It works for me.

:loop
cls
"C:\Program Files\NVIDIA Corporation\NVSMI\nvidia-smi"
timeout /T 1
goto loop

nvidia-smi exe is usually located in "C:\Program Files\NVIDIA Corporation" if you want to run the command only once.

enable cors in .htaccess

Should't the .htaccess use add instead of set?

Header add Access-Control-Allow-Origin "*"
Header add Access-Control-Allow-Methods: "GET,POST,OPTIONS,DELETE,PUT"

How to use the addr2line command in Linux?

That's exactly how you use it. There is a possibility that the address you have does not correspond to something directly in your source code though.

For example:

$ cat t.c
#include <stdio.h>
int main()
{
    printf("hello\n");
    return 0;
}
$ gcc -g t.c
$ addr2line -e a.out 0x400534
/tmp/t.c:3
$ addr2line -e a.out 0x400550
??:0

0x400534 is the address of main in my case. 0x400408 is also a valid function address in a.out, but it's a piece of code generated/imported by GCC, that has no debug info. (In this case, __libc_csu_init. You can see the layout of your executable with readelf -a your_exe.)

Other times when addr2line will fail is if you're including a library that has no debug information.

Python:Efficient way to check if dictionary is empty or not

Just check the dictionary:

d = {'hello':'world'}
if d:
  print 'not empty'
else:
  print 'empty'

d = {}
if d:
  print 'not empty'
else:
  print 'empty'

Install .ipa to iPad with or without iTunes

If you built the IPA using PhoneGap Build online you can download and install the IPA directly on your Ipad/Iphone by opening build.phonegap.com in Safari on the device, logging in and then clicking the iOS tab (the download ipa button). You will then be asked to install the app you built.

Direct link to this after logging in is: https://build.phonegap.com/apps/YOUR-BUILD-NUMBER/download/ios

Forward request headers from nginx proxy server

If you want to pass the variable to your proxy backend, you have to set it with the proxy module.

location / {
    proxy_pass                      http://example.com;
    proxy_set_header                Host example.com;
    proxy_set_header                HTTP_Country-Code $geoip_country_code;
    proxy_pass_request_headers      on;
}

And now it's passed to the proxy backend.

c++ "Incomplete type not allowed" error accessing class reference information (Circular dependency with forward declaration)

Here is what I had and what caused my "incomplete type error":

#include "X.h" // another already declared class
class Big {...} // full declaration of class A

class Small : Big {
    Small() {}
    Small(X); // line 6
}
//.... all other stuff

What I did in the file "Big.cpp", where I declared the A2's constructor with X as a parameter is..

Big.cpp

Small::Big(X my_x) { // line 9 <--- LOOK at this !
}

I wrote "Small::Big" instead of "Small::Small", what a dumb mistake.. I received the error "incomplete type is now allowed" for the class X all the time (in lines 6 and 9), which made a total confusion..

Anyways, that is where a mistake can happen, and the main reason is that I was tired when I wrote it and I needed 2 hours of exploring and rewriting the code to reveal it.

css transform, jagged edges in chrome

If you are using transition instead of transform, -webkit-backface-visibility: hidden; does not work. A jagged edge appears during animation for a transparent png file.

To solve it I used: outline: 1px solid transparent;

fork and exec in bash

Use the ampersand just like you would from the shell.

#!/usr/bin/bash
function_to_fork() {
   ...
}

function_to_fork &
# ... execution continues in parent process ...

How can I get the first two digits of a number?

Comparing the O(n) time solution with the "constant time" O(1) solution provided in other answers goes to show that if the O(n) algorithm is fast enough, n may have to get very large before it is slower than a slow O(1).

The strings version is approx. 60% faster than the "maths" version for numbers of 20 or fewer digits. They become closer only when then number of digits approaches 200 digits

# the "maths" version
import math

def first_n_digits1(num, n):
    return num // 10 ** (int(math.log(num, 10)) - n + 1)

%timeit first_n_digits1(34523452452, 2)
1.21 µs ± 75 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits1(34523452452, 8)
1.24 µs ± 47.5 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 22 digits
%timeit first_n_digits1(3423234239472523452452, 2)
1.33 µs ± 59.4 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits1(3423234239472523452452, 15)
1.23 µs ± 61.2 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 196 digits
%timeit first_n_digits1(3423234239472523409283475908723908723409872390871243908172340987123409871234012089172340987734507612340981344509873123401234670350981234098123140987314509812734091823509871345109871234098172340987125988123452452, 39)
1.86 µs ± 21.8 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)

# The "string" verions
def first_n_digits2(num, n):
    return int(str(num)[:n])

%timeit first_n_digits2(34523452452, 2)
744 ns ± 28.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits2(34523452452, 8)
768 ns ± 42.7 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 22 digits
%timeit first_n_digits2(3423234239472523452452, 2)
767 ns ± 33.6 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits2(3423234239472523452452, 15)
830 ns ± 55.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 196 digits
%timeit first_n_digits2(3423234239472523409283475908723908723409872390871243908098712340987123401208917234098773450761234098134450987312340123467035098123409812314098734091823509871345109871234098172340987125988123452452, 39)
1.87 µs ± 140 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)

How to break lines in PowerShell?

Just in case someone else comes across this, to clarify the answer `n is grave accent n, not single tick n

c++ string array initialization

Prior to C++11, you cannot initialise an array using type[]. However the latest c++11 provides(unifies) the initialisation, so you can do it in this way:

string* pStr = new string[3] { "hi", "there"};

See http://www2.research.att.com/~bs/C++0xFAQ.html#uniform-init

Does it matter what extension is used for SQLite database files?

Emacs expects one of db, sqlite, sqlite2 or sqlite3 in the default configuration for sql-sqlite mode.

How do I access call log for android?

in My project i am getting error int htc device.now this code is universal. I think this is help for you. 

    public class CustomContentObserver extends ContentObserver {        
    public CustomContentObserver(Handler handler) {
        super(handler);
        System.out.println("Content obser");
    }     

    public void onChange(boolean selfChange) {
         super.onChange(selfChange);
         String lastCallnumber;

         currentDate = sdfcur.format(calender.getTime());
         System.out.println("Content obser onChange()");
         Log.d("PhoneService", "custom StringsContentObserver.onChange( " + selfChange + ")");
        //if(!callFlag){                   
         String[] projection = new String[]{CallLog.Calls.NUMBER,
                    CallLog.Calls.TYPE,
                    CallLog.Calls.DURATION,
                    CallLog.Calls.CACHED_NAME,
                    CallLog.Calls._ID};

            Cursor c;   
            c=mContext.getContentResolver().query(CallLog.Calls.CONTENT_URI, projection, null, null, CallLog.Calls._ID + " DESC");
            if(c.getCount()!=0){
                c.moveToFirst();
                 lastCallnumber = c.getString(0);
                 String type=c.getString(1);
                 String duration=c.getString(2);
                 String name=c.getString(3);
                 String id=c.getString(4);
                 System.out.println("CALLLLing:"+lastCallnumber+"Type:"+type);

                 Database db=new Database(mContext);
                 Cursor cur =db.getFirstRecord(lastCallnumber);
                 final String endCall=lastCallnumber;
                 //checking incoming/outgoing call
                 if(type.equals("3")){
                    //missed call
                    }else if(type.equals("1")){
                    //incoming call

                 }else if(type.equals("2")){
                    //outgoing call
                 }                  

            }
            c.close();
    }

}

How to output (to a log) a multi-level array in a format that is human-readable?

This will help you

echo '<pre>';

$output = print_r($array,1);

echo '</pre>';

EDIT

using echo '<pre>'; is useless, but var_export($var); will do the thing which you are expecting.

How to find index position of an element in a list when contains returns true

Here is an example:

List<String> names;
names.add("toto");
names.add("Lala");
names.add("papa");
int index = names.indexOf("papa"); // index = 2

The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path

Add a runtime first and select project properties. Then check the server name from the 'Runtimes' tab as shown in the image.

Select runtime from Project Facets as shown the in image

How to list active / open connections in Oracle?

 
select status, count(1) as connectionCount from V$SESSION group by status;

How to get controls in WPF to fill available space?

Use the HorizontalAlignment and VerticalAlignment layout properties. They control how an element uses the space it has inside its parent when more room is available than it required by the element.

The width of a StackPanel, for example, will be as wide as the widest element it contains. So, all narrower elements have a bit of excess space. The alignment properties control what the child element does with the extra space.

The default value for both properties is Stretch, so the child element is stretched to fill all available space. Additional options include Left, Center and Right for HorizontalAlignment and Top, Center and Bottom for VerticalAlignment.

How to use a keypress event in AngularJS?

Another simple alternative: 

<input ng-model="edItem" type="text" 
    ng-keypress="($event.which === 13)?foo(edItem):0"/>

And the ng-ui alternative:

<input ng-model="edItem" type="text" ui-keypress="{'enter':'foo(edItem)'}"/>

How to convert an array of strings to an array of floats in numpy?

If you have (or create) a single string, you can use np.fromstring:

import numpy as np
x = ["1.1", "2.2", "3.2"]
x = ','.join(x)
x = np.fromstring( x, dtype=np.float, sep=',' )

Note, x = ','.join(x) transforms the x array to string '1.1, 2.2, 3.2'. If you read a line from a txt file, each line will be already a string.

Converting String to Int with Swift

An Int in Swift contains an initializer that accepts a String. It returns an optional Int? as the conversion can fail if the string contains not a number.

By using an if let statement you can validate whether the conversion succeeded.

So your code become something like this: 

@IBOutlet var txtBox1 : UITextField
@IBOutlet var txtBox2 : UITextField
@IBOutlet var txtBox3 : UITextField
@IBOutlet var lblAnswer : UILabel

@IBAction func btn1(sender : AnyObject) {

    let answer1 = "The acceleration is"
    var answer2 = txtBox1
    var answer3 = txtBox2
    var answer4 = txtBox3

    if let intAnswer = Int(txtBox1.text) {
      // Correctly converted
    }
}

Double border with different color

you can add infinite borders using box-shadow using css3 suppose you want to apply multiple borders on one div then code is like:

div {
    border-radius: 4px;
    /* #1 */
    border: 5px solid hsl(0, 0%, 40%);
    
    /* #2 */
    padding: 5px;
    background: hsl(0, 0%, 20%);
    
    /* #3 */
    outline: 5px solid hsl(0, 0%, 60%);
    
    /* #4 AND INFINITY!!! (CSS3 only) */
    box-shadow:
        0 0 0 10px red,
        0 0 0 15px orange,
        0 0 0 20px yellow,
        0 0 0 25px green,
        0 0 0 30px blue;
}

Get the current user, within an ApiController action, without passing the userID as a parameter

In .Net Core use User.Identity.Name to get the Name claim of the user.

Change the mouse cursor on mouse over to anchor-like style

Assuming your div has an id="myDiv", add the following to your CSS. The cursor: pointer specifies that the cursor should be the same hand icon that is use for anchors (hyperlinks):

CSS to Add

#myDiv
{
    cursor: pointer;
}

You can simply add the cursor style to your div's HTML like this:

<div style="cursor: pointer">

</div>

EDIT:

If you are determined to use jQuery for this, then add the following line to your $(document).ready() or body onload: (replace myClass with whatever class all of your divs share)

$('.myClass').css('cursor', 'pointer');

Reference - What does this regex mean?

The Stack Overflow Regular Expressions FAQ

See also a lot of general hints and useful links at the tag details page.

Online tutorials

Quantifiers

Character Classes

Escape Sequences

Anchors

(Also see "Flavor-Specific Information ? Java ? The functions in Matcher")

Groups

Lookarounds

Modifiers

flag modifier flavors
c current position
e expression
g global most
i case-insensitive most
m multiline
m (non)multiline
o once
S study
s single line unsupported: (workaround) |
U ungreedy
u unicode most
x whitespace-extended most
y sticky ?

Other:

Common Tasks

Advanced Regex-Fu

Flavor-Specific Information

(Except for those marked with *, this section contains non-Stack Overflow links.)

General information

(Links marked with * are non-Stack Overflow links.)

Examples of regex that can cause regex engine to fail

Tools: Testers and Explainers

(This section contains non-Stack Overflow links.)

notifyDataSetChanged example

I know this is a late response but I was facing a similar issue and I managed to solve it by using notifyDataSetChanged() in the right place.

So my situation was as follows.

I had to update a listview in an action bar tab (fragment) with contents returned from a completely different activity. Initially however, the listview would not reflect any changes. However, when I clicked another tab and then returned to the desired tab,the listview would be updated with the correct content from the other activity. So to solve this I used notifyDataSetChanged() of the action bar adapter in the code of the activity which had to return the data.

This is the code snippet which I used in the activity. 

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    switch (item.getItemId()) 
    {
        case R.id.action_new_forward:

            FragmentTab2.mListAdapter.notifyDataSetChanged();//this updates the adapter in my action bar tab
            Intent ina = new Intent(getApplicationContext(), MainActivity.class);
            ina.putExtra("stra", values1);
            startActivity(ina);// This is the code to start the parent activity of my action bar tab(fragment).
    }
}

This activity would return some data to FragmentTab2 and it would directly update my listview in FragmentTab2.

Hope someone finds this useful!

Check string length in PHP

The xpath() function does not return a string. It returns an array with XML elements (of type SimpleXMLElement), which may be casted to a string.

if (count($message)) {
   if (strlen((string)$message[0]) < 141) {
      echo "There Are No Contests.";
   }
   else if(strlen((string)$message[0]) > 142) {
      echo "There is One Active Contest.";
   }
}

How to include() all PHP files from a directory?

 
foreach (glob("classes/*.php") as $filename)
{
    include $filename;
}

MD5 is 128 bits but why is it 32 characters?

Those are hexidecimal digits, not characters. One digit = 4 bits.

Create Excel file in Java

Flat files do not allow providing meta information.

I would suggest writing out a HTML table containing the information you need, and let Excel read it instead. You can then use <b> tags to do what you ask for.

JavaScript Form Submit - Confirm or Cancel Submission Dialog Box

OK, just change your code to something like this:

<script>
function submit() {
   return confirm('Do you really want to submit the form?');
}
</script>

<form onsubmit="return submit(this);">
   <input type="image" src="xxx" border="0" name="submit" onclick="show_alert();"
      alt="PayPal - The safer, easier way to pay online!" value="Submit">
</form>

Also this is the code in run, just I make it easier to see how it works, just run the code below to see the result:

_x000D_
_x000D_ 
function submitForm() {_x000D_
  return confirm('Do you really want to submit the form?');_x000D_
}
_x000D_ 
<form onsubmit="return submitForm(this);">_x000D_
  <input type="text" border="0" name="submit" />_x000D_
  <button value="submit">submit</button>_x000D_
</form>
_x000D_
_x000D_
_x000D_

MVC4 HTTP Error 403.14 - Forbidden

Before applying

runAllManagedModulesForAllRequests="true"/>

consider the link below that suggests a less drastic alternative. In the post the author offers the following alteration to the local web.config:

  <system.webServer>
    <modules>
    <remove name="UrlRoutingModule-4.0" />
    <add name="UrlRoutingModule-4.0" type="System.Web.Routing.UrlRoutingModule" preCondition="" />
    </modules>

http://www.britishdeveloper.co.uk/2010/06/dont-use-modules-runallmanagedmodulesfo.html

How can I put a database under git (version control)?

You can't do it without atomicity, and you can't get atomicity without either using pg_dump or a snapshotting filesystem.

My postgres instance is on zfs, which I snapshot occasionally. It's approximately instant and consistent.

How to find Google's IP address?

nslookup google.com is the easiest way. Works on Linux and Windows.

If your issue is that your DNS server is not returning a response for google.com, use a different DNS server, such as a public one. For instance, you could do:

nslookup
>server 8.8.8.8
>google.com

For a more thorough solution to getting around annoying Internet filters, look into using Tor.

SQL permissions for roles

Unless the role was made dbo, db_owner or db_datawriter, it won't have permission to edit any data. If you want to grant full edit permissions to a single table, do this:

GRANT ALL ON table1 TO doctor

Users in that role will have no permissions whatsoever to other tables (not even read).

How many times does each value appear in a column?

I second Dave's idea. I'm not always fond of pivot tables, but in this case they are pretty straightforward to use.

Here are my results:

Enter image description here

It was so simple to create it that I have even recorded a macro in case you need to do this with VBA:

Sub Macro2()
'
' Macro2 Macro
'

'
    Range("Table1[[#All],[DATA]]").Select
    ActiveWorkbook.PivotCaches.Create(SourceType:=xlDatabase, SourceData:= _
        "Table1", Version:=xlPivotTableVersion14).CreatePivotTable TableDestination _
        :="Sheet3!R3C7", TableName:="PivotTable4", DefaultVersion:= _
        xlPivotTableVersion14
    Sheets("Sheet3").Select
    Cells(3, 7).Select
    With ActiveSheet.PivotTables("PivotTable4").PivotFields("DATA")
        .Orientation = xlRowField
        .Position = 1
    End With
    ActiveSheet.PivotTables("PivotTable4").AddDataField ActiveSheet.PivotTables( _
        "PivotTable4").PivotFields("DATA"), "Count of DATA", xlCount
End Sub

removing new line character from incoming stream using sed

To remove newlines, use tr:

tr -d '\n'

If you want to replace each newline with a single space:

tr '\n' ' '

The error ba: Event not found is coming from csh, and is due to csh trying to match !ba in your history list. You can escape the ! and write the command:

sed ':a;N;$\!ba;s/\n/ /g'  # Suitable for csh only!!

but sed is the wrong tool for this, and you would be better off using a shell that handles quoted strings more reasonably. That is, stop using csh and start using bash.

Write to custom log file from a Bash script

If you see the man page of logger: 

$ man logger

LOGGER(1) BSD General Commands Manual LOGGER(1)

NAME logger — a shell command interface to the syslog(3) system log module

SYNOPSIS logger [-isd] [-f file] [-p pri] [-t tag] [-u socket] [message ...]

DESCRIPTION Logger makes entries in the system log. It provides a shell command interface to the syslog(3) system log module.

It Clearly says that it will log to system log. If you want to log to file, you can use ">>" to redirect to log file.

How to pass arguments and redirect stdin from a file to program run in gdb?

Wouldn't it be nice to just type debug in front of any command to be able to debug it with gdb on shell level?

Below it this function. It even works with following:

"$program" "$@" < <(in) 1> >(out) 2> >(two) 3> >(three)

This is a call where you cannot control anything, everything is variable, can contain spaces, linefeeds and shell metacharacters. In this example, in, out, two, and three are arbitrary other commands which consume or produce data which must not be harmed.

Following bash function invokes gdb nearly cleanly in such an environment [Gist]:

debug()
{
  1000<&0 1001>&1 1002>&2 \
  0</dev/tty 1>/dev/tty 2>&0 \
  /usr/bin/gdb -q -nx -nw \
  -ex 'set exec-wrapper /bin/bash -c "exec 0<&1000 1>&1001 2>&1002 \"\$@\"" exec' \
  -ex r \
  --args "$@";
}

Example on how to apply this: Just type debug in front:

Before:

p=($'\n' $'I\'am\'evil' "  yay  ")
"b u g" "${p[@]}" < <(in) 1> >(out) 2> >(two) 3> >(three)

After:

p=($'\n' $'I\'am\'evil' "  yay  ")
debug "b u g" "${p[@]}" < <(in) 1> >(out) 2> >(two) 3> >(three)

That's it. Now it's an absolute no-brainer to debug with gdb. Except for a few details or more:

  • gdb does not quit automatically and hence keeps the IO redirection open until you exit gdb. But I call this a feature.

  • You cannot easily pass argv0 to the program like with exec -a arg0 command args. Following should do this trick: After exec-wrapper change "exec to "exec -a \"\${DEBUG_ARG0:-\$1}\".

  • There are FDs above 1000 open, which are normally closed. If this is a problem, change 0<&1000 1>&1001 2>&1002 to read 0<&1000 1>&1001 2>&1002 1000<&- 1001>&- 1002>&-

  • You cannot run two debuggers in parallel. There also might be issues, if some other command consumes /dev/tty (or STDIN). To fix that, replace /dev/tty with "${DEBUGTTY:-/dev/tty}". In some other TTY type tty; sleep inf and then use the printed TTY (i. E. /dev/pts/60) for debugging, as in DEBUGTTY=/dev/pts/60 debug command arg... That's the Power of Shell, get used to it!

Function explained:

  • 1000<&0 1001>&1 1002>&2 moves away the first 3 FDs
    • This assumes, that FDs 1000, 1001 and 1002 are free
  • 0</dev/tty 1>/dev/tty 2>&0 restores the first 3 FDs to point to your current TTY. So you can control gdb.
  • /usr/bin/gdb -q -nx -nw runs gdb invokes gdb on shell
  • -ex 'set exec-wrapper /bin/bash -c "exec 0<&1000 1>&1001 2>&1002 \"\$@\"" creates a startup wrapper, which restores the first 3 FDs which were saved to 1000 and above
  • -ex r starts the program using the exec-wrapper
  • --args "$@" passes the arguments as given

Wasn't that easy?

iPhone get SSID without private library

Here's the cleaned up ARC version, based on @elsurudo's code:

- (id)fetchSSIDInfo {
     NSArray *ifs = (__bridge_transfer NSArray *)CNCopySupportedInterfaces();
     NSLog(@"Supported interfaces: %@", ifs);
     NSDictionary *info;
     for (NSString *ifnam in ifs) {
         info = (__bridge_transfer NSDictionary *)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
         NSLog(@"%@ => %@", ifnam, info);
         if (info && [info count]) { break; }
     }
     return info;
}

CreateProcess: No such file or directory

I had a very long path, and there's a file in there somewhere (not gcc.exe) but another file, that gcc.exe is accessing from the path..

So when I cleared the path, it worked

C:\MinGW>cd bin


C:\MinGW\bin>where gcc.exe
C:\MinGW\bin\gcc.exe
C:\Perl64\site\bin\gcc.exe

^^ So running gcc from there will definitely run the ming gcc.exe

C:\MinGW\bin>type file6.c
#include<stdio.h>
void main()
{
int num1,num2;
scanf("%2d %4d",&num1,&num2);
printf("a=%d b=%d",num1,num2);
scanf("%d",&num1);
//flushall();
printf("c=%d",num1);
}

Compiling it I got this error

C:\MinGW\bin>gcc file6.c
gcc: error: CreateProcess: No such file or directory

My PATH was huge

C:\MinGW\bin>path
PATH=C:\Windows\system32;C:\Windows;C:\Windows\system32\wbem;C:\P......

C:\MinGW\bin>path | grep -io "ming"

It didn't have ming there.

C:\MinGW\bin>echo MING | grep -io "ming" MING

(and yeah that grep works..the path didn't have ming there)

Clearing my path completely, led it to work!

C:\MinGW\bin>set PATH=

C:\MinGW\bin>gcc file6.c

C:\MinGW\bin>

So, it's not clear yet precisely what it was in the PATH that led to the clash. What directory, what file.

Update-

The above seems to be correct to me but to add, it's also not a simple case of something earlier in the path clashing.. because normally the current directory takes precedence. And it does here in so far as gcc --version shows it's running the ming one and not one of the ones in a conflicting directory. So there's something funny going on that, if the conflicting directory is in the path) , one has to either do .\gcc or add . to the start of the path or add c:\MinGW\bin before any conflicting directories in the path. this is the case even when you're in C:\MinGW\bin and that's strange. And when it gives an error, it is still running Ming's gcc but (For some reason) looking at the conflicting directory too, as I see from process monitor. There may be more of an answer here http://wiki.codeblocks.org/index.php?title=Installing_MinGW_with_Vista in the link mentioned in the very upvoted answer here

That's Ming32 bit..

Looking at Ming 64bit, probably has te same issue, but I see, interestingly, it comes with a bat file that (sensibly) actually puts the bin directory at the tart of the path. And it looks like that is a standard way of running Ming gcc properly.

The code::blocks IDE (sensibly) also puts the bin directory at the start of the path. If you run a C program that shows environment variables then you see that.

Add line break within tooltips

Give \n between the text. It work on all browsers.

Example 
img.tooltip= " Your Text : \n"
img.tooltip += " Your text \n";

This will work for me and it's used in code behind.

Hope this will work for you

A good Sorted List for Java

Depending on how you're using the list, it may be worth it to use a TreeSet and then use the toArray() method at the end. I had a case where I needed a sorted list, and I found that the TreeSet + toArray() was much faster than adding to an array and merge sorting at the end.

Split string, convert ToList<int>() in one line

You can use this: 

List<Int32> sNumberslst = sNumbers.Split(',').ConvertIntoIntList();

How do you do relative time in Rails?

Something like this would work.

def relative_time(start_time)
  diff_seconds = Time.now - start_time
  case diff_seconds
    when 0 .. 59
      puts "#{diff_seconds} seconds ago"
    when 60 .. (3600-1)
      puts "#{diff_seconds/60} minutes ago"
    when 3600 .. (3600*24-1)
      puts "#{diff_seconds/3600} hours ago"
    when (3600*24) .. (3600*24*30) 
      puts "#{diff_seconds/(3600*24)} days ago"
    else
      puts start_time.strftime("%m/%d/%Y")
  end
end

Regular Expression for any number greater than 0?

I think the best solution is to add the + sign between the two brackets of regex expression:

^[1-9]+[0-9]*$

Explanation of BASE terminology

It could just be because ACID is one set of properties that substances show( in Chemistry) and BASE is a complement set of them.So it could be just to show the contrast between the two that the acronym was made up and then 'Basically Available Soft State Eventual Consistency' was decided as it's full-form.

C# Copy a file to another location with a different name

 
System.IO.File.Copy(oldPathAndName, newPathAndName);

What is Vim recording and how can it be disabled?

Typing q starts macro recording, and the recording stops when the user hits q again.

As Joey Adams mentioned, to disable recording, add the following line to .vimrc in your home directory:

map q <Nop>

Break or return from Java 8 stream forEach?

Update with Java 9+ with takeWhile:

MutableBoolean ongoing = MutableBoolean.of(true);
someobjects.stream()...takeWhile(t -> ongoing.value()).forEach(t -> {
    // doing something.
    if (...) { // want to break;
        ongoing.setFalse();
    }
});

jQuery Scroll To bottom of the page

For jQuery 3, Please change

$(window).load(function() { $("html, body").animate({ scrollTop: $(document).height() }, 1000); })

to:

$(window).on("load", function (e) { $("html, body").animate({ scrollTop: $(document).height() }, 1000); })

Wait till a Function with animations is finished until running another Function

This answer uses promises, a JavaScript feature of the ECMAScript 6 standard. If your target platform does not support promises, polyfill it with PromiseJs.

You can get the Deferred object jQuery creates for the animation using .promise() on the animation call. Wrapping these Deferreds into ES6 Promises results in much cleaner code than using timers.

You can also use Deferreds directly, but this is generally discouraged because they do not follow the Promises/A+ specification.

The resulting code would look like this:

var p1 = Promise.resolve($('#Content').animate({ opacity: 0.5 }, { duration: 500, queue: false }).promise());
var p2 = Promise.resolve($('#Content').animate({ marginLeft: "-100px" }, { duration: 2000, queue: false }).promise());
Promise.all([p1, p2]).then(function () {
    return $('#Content').animate({ width: 0 }, { duration: 500, queue: false }).promise();
});

Note that the function in Promise.all() returns the promise. This is where magic happens. If in a then call a promise is returned, the next then call will wait for that promise to be resolved before executing.

jQuery uses an animation queue for each element. So animations on the same element are executed synchronously. In this case you wouldn't have to use promises at all!

I have disabled the jQuery animation queue to demonstrate how it would work with promises.

Promise.all() takes an array of promises and creates a new Promise that finishes after all promises in the array finished.

Promise.race() also takes an array of promises, but finishes as soon as the first Promise finished.

Editing hosts file to redirect url?

Apply this trick.

First you need IP address of url you want to redirect to. Lets say you want to redirect to stackoverflow.com To find it, use the ping command in a Command Prompt. Type in:

ping stackoverflow.com

into the command prompt window and you’ll see stackoverflow's numerical IP address. Now use that IP into your host file

104.16.36.249 google.com

yay now google is serving stackoverflow :)

Why is System.Web.Mvc not listed in Add References?

I have had the same problem and here is the funny reason: My guess is that you expect System.Web.Mvc to be located under System.Web in the list. But the list is not alphabetical.

First sort the list and then look near the System.Web.

JavaScript variable number of arguments to function

Use the arguments object when inside the function to have access to all arguments passed in.

How do I add multiple "NOT LIKE '%?%' in the WHERE clause of sqlite3?

You missed the second statement: 1) NOT LIKE A, AND 2) NOT LIKE B

SELECT word FROM table WHERE word NOT LIKE '%a%' AND word NOT LIKE '%b%'

How to tell if a <script> tag failed to load

The reason it doesn't work in Safari is because you're using attribute syntax. This will work fine though:

script_tag.addEventListener('error', function(){/*...*/}, true);

...except in IE.

If you want to check the script executed successfully, just set a variable using that script and check for it being set in the outer code.

Image library for Python 3

The "friendly PIL fork" Pillow works on Python 2 and 3. Check out the Github project for support matrix and so on.

Enter key press in C#

Try this code,might work (Assuming windows form):

private void CheckEnter(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
    if (e.KeyChar == (char)13)
    {
        // Enter key pressed
    }
}

Register the event like this :

this.textBox1.KeyPress += new 
System.Windows.Forms.KeyPressEventHandler(CheckEnter);

Android: Clear Activity Stack

Here is a simple helper method for starting a new activity as the new top activity which works from API level 4 up until the current version 17:

static void startNewMainActivity(Activity currentActivity, Class<? extends Activity> newTopActivityClass) {
    Intent intent = new Intent(currentActivity, newTopActivityClass);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
        intent.addFlags(0x8000); // equal to Intent.FLAG_ACTIVITY_CLEAR_TASK which is only available from API level 11
    currentActivity.startActivity(intent);
}

call it like this from your current activity:

startNewMainActivity(this, MainActivity.class);

Total width of element (including padding and border) in jQuery

Anyone else stumbling upon this answer should note that jQuery now (>=1.3) has outerHeight/outerWidth functions to retrieve the width including padding/borders, e.g.

$(elem).outerWidth(); // Returns the width + padding + borders

To include the margin as well, simply pass true:

$(elem).outerWidth( true ); // Returns the width + padding + borders + margins

How to easily get network path to the file you are working on?

I realise this is a slightly old question, but it was driving me crazy too - and today I've found the solution that I believe the questioner was looking for (i.e. a direct mapping of Excel 2003's Web-->Address to the Excel 2010 Ribbon).

To customise the Ribbon, right-click on it and choose 'Customise the Ribbon'. You can make a new tab/group, or add this to an existing one. Choose to look in "All commands" and then the one you are after is simply called "Address". This puts a box with the full network path in it (that can be selected to copy) into the ribbon, just like Excel 2003.

How can I make a JPA OneToOne relation lazy

If the child entity is used readonly, then it's possible to simply lie and set optional=false. Then ensure that every use of that mapped entity is preloaded via queries.

public class App {
  ...
  @OneToOne(mappedBy = "app", fetch = FetchType.LAZY, optional = false)
  private Attributes additional;

and

String sql = " ... FROM App a LEFT JOIN FETCH a.additional aa ...";

... maybe even persisting would work...

Can I set the height of a div based on a percentage-based width?

I made a CSS approach to this that is sized by the viewport width, but maxes out at 100% of the viewport height. It doesn't require box-sizing:border-box. If a pseudo element cannot be used, the pseudo-code's CSS can be applied to a child. Demo

.container {
  position: relative;
  max-width:100vh;
  max-height:100%;
  margin:0 auto;
  overflow: hidden;
}
.container:before {
  content: "";
  display: block;
  margin-top: 100%;
}
.child {
  position: absolute;
  top: 0;
  left: 0;
}

Support table for viewport units

I wrote about this approach and others in a CSS-Tricks article on scaling responsive animations that you should check out.

How to start mongodb shell?

You need to find the bin folder and then open a command prompt on that folder Then just type mongo.exe and press enter to start the shell

Or you can supply the full path to mongo.exe from any folder to start the shell:

c:\MongoDB\bin\mongo.exe

Then if you have multiple databases, you can do enter command >use <database_name> to use that db

Let me know if it helps or have issues

How to concatenate properties from multiple JavaScript objects

Simplest: spread operators

var obj1 = {a: 1}
var obj2 = {b: 2}
var concat = { ...obj1, ...obj2 } // { a: 1, b: 2 }

python numpy ValueError: operands could not be broadcast together with shapes

You are looking for np.matmul(X, y). In Python 3.5+ you can use X @ y.

How do I get formatted JSON in .NET using C#?

netcoreapp3.1

var js = JsonSerializer.Serialize(obj, new JsonSerializerOptions {
             WriteIndented = true
         });

canvas.toDataURL() SecurityError

By using fabric js we can solve this security error issue in IE.

    function getBase64FromImageUrl(URL) {
        var canvas  = new fabric.Canvas('c');
        var img = new Image();
        img.onload = function() {
            var canvas1 = document.createElement("canvas");
            canvas1.width = this.width;
            canvas1.height = this.height;
            var ctx = canvas.getContext('2d');
            ctx.drawImage(this, 0, 0);
            var dataURL = canvas.toDataURL({format: "png"});
        };
        img.src = URL;
    }

How to test that no exception is thrown?

Use assertNull(...)

@Test
public void foo() {
    try {
        //execute code that you expect not to throw Exceptions.
    } catch (Exception e){
        assertNull(e);
    }
}

how to add script inside a php code?

To avoid escaping lot of characters:

   echo <<<MYSCRIPT

    ... script here...

    MYSCRIPT;

or just turn off php parsing for a while:

?>
...your script here
<?php

Efficient method to generate UUID String in JAVA (UUID.randomUUID().toString() without the dashes)

A simple solution is

UUID.randomUUID().toString().replace("-", "")

(Like the existing solutions, only that it avoids the String#replaceAll call. Regular expression replacement is not required here, so String#replace feels more natural, though technically it still is implemented with regular expressions. Given that the generation of the UUID is more costly than the replacement, there should not be a significant difference in runtime.)

Using the UUID class is probably fast enough for most scenarios, though I would expect that some specialized hand-written variant, which does not need the postprocessing, to be faster. Anyway, the bottleneck of the overall computation will normally be the random number generator. In case of the UUID class, it uses SecureRandom.

Which random number generator to use is also a trade-off that depends on the application. If it is security-sensitive, SecureRandom is, in general, the recommendation. Otherwise, ThreadLocalRandom is an alternative (faster than SecureRandom or the old Random, but not cryptographically secure).

Storing integer values as constants in Enum manner in java

You could store that const value in the enum like so. But why even use the const? Are you persisting the enum's?

public class SO3990319 {
   public static enum PAGE {
      SIGN_CREATE(1);
      private final int constValue;

      private PAGE(int constValue) {
         this.constValue = constValue;
      }

      public int constValue() {
         return constValue;
      }
   }

   public static void main(String[] args) {
      System.out.println("Name:    " + PAGE.SIGN_CREATE.name());
      System.out.println("Ordinal: " + PAGE.SIGN_CREATE.ordinal());
      System.out.println("Const:   " + PAGE.SIGN_CREATE.constValue());

      System.out.println("Enum: " + PAGE.valueOf("SIGN_CREATE"));
   }
}

Edit:

It depends on what you're using the int's for whether to use EnumMap or instance field.

How to read integer value from the standard input in Java

check this one:

import java.io.*;
public class UserInputInteger
{
        public static void main(String args[])throws IOException
        {
        InputStreamReader read = new InputStreamReader(System.in);
        BufferedReader in = new BufferedReader(read);
        int number;
                System.out.println("Enter the number");
                number = Integer.parseInt(in.readLine());
    }
}

Git Ignores and Maven targets

add following lines in gitignore, from all undesirable files

/target/
*/target/**
**/META-INF/
!.mvn/wrapper/maven-wrapper.jar

### STS ###
.apt_generated
.classpath
.factorypath
.project
.settings
.springBeans
.sts4-cache

### IntelliJ IDEA ###
.idea
*.iws
*.iml
*.ipr

### NetBeans ###
/nbproject/private/
/build/
/nbbuild/
/dist/
/nbdist/
/.nb-gradle/

I keep getting this error for my simple python program: "TypeError: 'float' object cannot be interpreted as an integer"

As shown below, range only supports integers:

>>> range(15.0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: range() integer end argument expected, got float.
>>> range(15)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
>>>

However, c/10 is a float because / always returns a float.

Before you put it in range, you need to make c/10 an integer. This can be done by putting it in int:

range(int(c/10))

or by using //, which returns an integer:

range(c//10)

Python using enumerate inside list comprehension

If you're using long lists, it appears the list comprehension's faster, not to mention more readable.

~$ python -mtimeit -s"mylist = ['a','b','c','d']" "list(enumerate(mylist))"
1000000 loops, best of 3: 1.61 usec per loop
~$ python -mtimeit -s"mylist = ['a','b','c','d']" "[(i, j) for i, j in enumerate(mylist)]"
1000000 loops, best of 3: 0.978 usec per loop
~$ python -mtimeit -s"mylist = ['a','b','c','d']" "[t for t in enumerate(mylist)]"
1000000 loops, best of 3: 0.767 usec per loop

Add/remove class with jquery based on vertical scroll?

In a similar case, I wanted to avoid always calling addClass or removeClass due to performance issues. I've split the scroll handler function into two individual functions, used according to the current state. I also added a debounce functionality according to this article: https://developers.google.com/web/fundamentals/performance/rendering/debounce-your-input-handlers

        var $header = jQuery( ".clearHeader" );         
        var appScroll = appScrollForward;
        var appScrollPosition = 0;
        var scheduledAnimationFrame = false;

        function appScrollReverse() {
            scheduledAnimationFrame = false;
            if ( appScrollPosition > 500 )
                return;
            $header.removeClass( "darkHeader" );
            appScroll = appScrollForward;
        }

        function appScrollForward() {
            scheduledAnimationFrame = false;
            if ( appScrollPosition < 500 )
                return;
            $header.addClass( "darkHeader" );
            appScroll = appScrollReverse;
        }

        function appScrollHandler() {
            appScrollPosition = window.pageYOffset;
            if ( scheduledAnimationFrame )
                return;
            scheduledAnimationFrame = true;
            requestAnimationFrame( appScroll );
        }

        jQuery( window ).scroll( appScrollHandler );

Maybe someone finds this helpful.

Unable to convert MySQL date/time value to System.DateTime

if "allow zero datetime=true" is not working then use the following sollutions:-

Add this to your connection string: "allow zero datetime=no" - that made the type cast work perfectly.

How to get the error message from the error code returned by GetLastError()?

Updated (11/2017) to take into consideration some comments.

Easy example:

wchar_t buf[256];
FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
               NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), 
               buf, (sizeof(buf) / sizeof(wchar_t)), NULL);

How does Java import work?

In dynamic languages, when the interpreter imports, it simply reads a file and evaluates it.

In C, external libraries are located by the linker at compile time to build the final object if the library is statically compiled, while for dynamic libraries a smaller version of the linker is called at runtime which remaps addresses and so makes code in the library available to the executable.

In Java, import is simply used by the compiler to let you name your classes by their unqualified name, let's say String instead of java.lang.String. You don't really need to import java.lang.* because the compiler does it by default. However this mechanism is just to save you some typing. Types in Java are fully qualified class names, so a String is really a java.lang.String object when the code is run. Packages are intended to prevent name clashes and allow two classes to have the same simple name, instead of relying on the old C convention of prefixing types like this. java_lang_String. This is called namespacing.

BTW, in Java there's the static import construct, which allows to further save typing if you use lots of constants from a certain class. In a compilation unit (a .java file) which declares

import static java.lang.Math.*;

you can use the constant PI in your code, instead of referencing it through Math.PI, and the method cos() instead of Math.cos(). So for example you can write

double r = cos(PI * theta);

Once you understand that classes are always referenced by their fully qualified name in the final bytecode, you must understand how the class code is actually loaded. This happens the first time an object of that class is created, or the first time a static member of the class is accessed. At this time, the ClassLoader tries to locate the class and instantiate it. If it can't find the class a NoClassDefFoundError is thrown (or a a ClassNotFoundException if the class is searched programmatically). To locate the class, the ClassLoader usually checks the paths listed in the $CLASSPATH environment variable.

To solve your problem, it seems you need an applet element like this

<applet
  codebase = "http://san.redenetimoveis.com"
  archive="test.jar, core.jar"
  code="com.colorfulwolf.webcamapplet.WebcamApplet"      
  width="550" height="550" >

BTW, you don't need to import the archives in the standard JRE.

Node.js - Maximum call stack size exceeded

You can use loop for.

var items = {1, 2, 3}
for(var i = 0; i < items.length; i++) {
  if(i == items.length - 1) {
    res.ok(i);
  }
}

What is Hive: Return Code 2 from org.apache.hadoop.hive.ql.exec.MapRedTask

I was also facing same error when I was inserting the data into HIVE external table which was pointing to Elastic search cluster.

I replaced the older JAR elasticsearch-hadoop-2.0.0.RC1.jar to elasticsearch-hadoop-5.6.0.jar, and everything worked fine.

My Suggestion is please use the specific JAR as per the elastic search version. Don't use older JARs if you are using newer version of elastic search.

Thanks to this post Hive- Elasticsearch Write Operation #409