Using jQuery To Get Size of Viewport

1. Response to the main question

The script $(window).height() does work well (showing the viewport's height and not the document with scrolling height), BUT it needs that you put correctly the doctype tag in your document, for example these doctypes:

For HTML 5:

<!DOCTYPE html>

For transitional HTML4:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Probably the default doctype assumed by some browsers is such, that $(window).height() takes the document's height and not the browser's height. With the doctype specification, it's satisfactorily solved, and I'm pretty sure you peps will avoid the "changing scroll-overflow to hidden and then back", which is, I'm sorry, a bit dirty trick, specially if you don't document it on the code for future programmer's usage.

2. An ADDITIONAL tip, note aside: Moreover, if you are doing a script, you can invent tests to help programmers in using your libraries, let me invent a couple:

~~$(document).ready(function() {~~

      if(typeof $=='undefined') {
        alert("PROGRAMMER'S Error: you haven't called JQuery library");
      } else if (typeof $.ui=='undefined') {
        alert("PROGRAMMER'S Error: you haven't installed the UI Jquery library");
      }
      if(document.doctype==null || screen.height < parseInt($(window).height()) ) {
        alert("ERROR, check your doctype, the calculated heights are not what you might expect");
      }

~~});~~

EDIT: about the part 2, "An ADDITIONAL tip, note aside": @Machiel, in yesterday's comment (2014-09-04), was UTTERLY right: the check of the $ can not be inside the ready event of Jquery, because we are, as he pointed out, assuming $ is already defined. THANKS FOR POINTING THAT OUT, and do please the rest of you readers correct this, if you used it in your scripts. My suggestion is: in your libraries put an "install_script()" function which initializes the library (put any reference to $ inside such init function, including the declaration of ready()) and AT THE BEGINNING of such "install_script()" function, check if the $ is defined, but make everything independent of JQuery, so your library can "diagnose itself" when JQuery is not yet defined. I prefer this method rather than forcing the automatic creation of a JQuery bringing it from a CDN. Those are tiny notes aside for helping out other programmers. I think that people who make libraries must be richer in the feedback to potential programmer's mistakes. For example, Google Apis need an aside manual to understand the error messages. That's absurd, to need external documentation for some tiny mistakes that don't need you to go and search a manual or a specification. The library must be SELF-DOCUMENTED. I write code even taking care of the mistakes I might commit even six months from now, and it still tries to be a clean and not-repetitive code, already-written-to-prevent-future-developer-mistakes.

Update built-in vim on Mac OS X

Like Eric, I used homebrew, but I used the default recipe. So:

brew install mercurial
brew install vim

And after restarting the terminal homebrew's vim should be the default. If not, you should update your $PATH so that /usr/local/bin is before /usr/bin. E.g. add the following to your .profile:

export PATH=/usr/local/bin:$PATH

How to shutdown my Jenkins safely?

If you would like to stop jenkins and all its services on the server using Linux console (e.g. Ubuntu), run:

service jenkins start/stop/restart

This is useful when you need to make an image/volume snapshot and you want all services to stop writing to the disk/volume.

Way to go from recursion to iteration

There is a general way of converting recursive traversal to iterator by using a lazy iterator which concatenates multiple iterator suppliers (lambda expression which returns an iterator). See my Converting Recursive Traversal to Iterator.

Sum of values in an array using jQuery

You can use reduce which works in all browser except IE8 and lower.

["20","40","80","400"].reduce(function(a, b) {
    return parseInt(a, 10) + parseInt(b, 10);
})

How do I split a string on a delimiter in Bash?

Here is a clean 3-liner:

in="foo@bar;bizz@buzz;fizz@buzz;buzz@woof"
IFS=';' list=($in)
for item in "${list[@]}"; do echo $item; done

where IFS delimit words based on the separator and () is used to create an array. Then [@] is used to return each item as a separate word.

If you've any code after that, you also need to restore $IFS, e.g. unset IFS.

destination path already exists and is not an empty directory

I got same issue while using cygwin to install nvm

In fact, the target directory where empty but the git binary used was the one from windows (and not git from cygwin git package).

After installing cygwin git package, the git clone from nvm install was ok!

Can I embed a .png image into an html page?

The 64base method works for large images as well, I use that method to embed all the images into my website, and it works every time. I've done with files up to 2Mb size, jpg and png.

Sql query to insert datetime in SQL Server

You will want to use the YYYYMMDD for unambiguous date determination in SQL Server.

insert into table1(approvaldate)values('20120618 10:34:09 AM');

If you are married to the dd-mm-yy hh:mm:ss xm format, you will need to use CONVERT with the specific style.

insert into table1 (approvaldate)
       values (convert(datetime,'18-06-12 10:34:09 PM',5));

5 here is the style for Italian dates. Well, not just Italians, but that's the culture it's attributed to in Books Online.

How can I disable ARC for a single file in a project?

The four Mandatory Step as explained in this video

    //1. Select desired files
    //2. Target/Build Phases/Compile Sources
    //3. Type -fno-objc-arc
    //4. Done

Error Code: 1406. Data too long for column - MySQL

I think that switching off the STRICT mode is not a good option because the app can start losing the data entered by users.

If you receive values for the TESTcol from an app you could add model validation, like in Rails

validates :TESTcol, length: { maximum: 45 }

If you manipulate with values in SQL script you could truncate the string with the SUBSTRING command

INSERT INTO TEST
VALUES
(
    1,
    SUBSTRING('Vikas Kumar Gupta Kratika Shukla Kritika Shukla', 0, 45)
);

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

This answer is almost exactly like selected answer but with two enhancements: it's a method and it closes out the FileOutputStream object:

    public static void downloadFileFromURL(String urlString, File destination) {    
        try {
            URL website = new URL(urlString);
            ReadableByteChannel rbc;
            rbc = Channels.newChannel(website.openStream());
            FileOutputStream fos = new FileOutputStream(destination);
            fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
            fos.close();
            rbc.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

How to get client's IP address using JavaScript?

Well, I am digressing from the question, but I had a similar need today and though I couldn't find the ID from the client using Javascript, I did the following.

On the server side: -

<div style="display:none;visibility:hidden" id="uip"><%= Request.UserHostAddress %></div>

Using Javascript

var ip = $get("uip").innerHTML;

I am using ASP.Net Ajax, but you can use getElementById instead of $get().

What's happening is, I've got a hidden div element on the page with the user's IP rendered from the server. Than in Javascript I just load that value.

This might be helpful to some people with a similar requirement like yours (like me while I hadn't figure this out).

Cheers!

Why is the minidlna database not being refreshed?

AzP already provided most of the information, but some of it is incorrect.

First of all, there is no such option inotify_interval. The only option that exists is notify_interval and has nothing to do with inotify.

So to clarify, notify_interval controls how frequently the (mini)dlna server announces itself in the network. The default value of 895 means it will announce itself about once every 15 minutes, meaning clients will need at most 15 minutes to find the server. I personally use 1-5 minutes depending on client volatility in the network.

In terms of getting minidlna to find files that have been added, there are two options:

The first is equivalent to removing the file files.db and consists in restarting minidlna while passing the -R argument, which forces a full rescan and builds the database from scratch. Since version 1.2.0 there's now also the -r argument which performs a rebuild action. This preserves any existing database and drops and adds old and new records, respectively.
The second is to rely on inotify events by setting inotify=yes and restarting minidlna. If inotify is set to =no, the only option to update the file database is the forced full rescan.

Additionally, in order to have inotify working, the file-system must support inotify events, which is not the case in most remote file-systems. If you have minidlna running over NFS it will not see any inotify events because these are generated on the server side and not on the client.

Finally, even if inotify is working and is supported by the file-system, the user under which minidlna is running must be able to read the file, otherwise it will not be able to retrieve necessary metadata. In this case, the logfile (usually /var/log/minidlna.log) should contain useful information.

How can I get a character in a string by index?

Do you mean like this

int index = 2;
string s = "hello";
Console.WriteLine(s[index]);

string also implements IEnumberable<char> so you can also enumerate it like this

foreach (char c in s)
    Console.WriteLine(c);

How to check certificate name and alias in keystore files?

KeyStore Explorer open source visual tool to manage keystores.

INSERT IF NOT EXISTS ELSE UPDATE?

You need to set a constraint on the table to trigger a "conflict" which you then resolve by doing a replace:

CREATE TABLE data   (id INTEGER PRIMARY KEY, event_id INTEGER, track_id INTEGER, value REAL);
CREATE UNIQUE INDEX data_idx ON data(event_id, track_id);

Then you can issue:

INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 2, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 5);

The "SELECT * FROM data" will give you:

2|2|2|3.0
3|1|2|5.0

Note that the data.id is "3" and not "1" because REPLACE does a DELETE and INSERT, not an UPDATE. This also means that you must ensure that you define all necessary columns or you will get unexpected NULL values.

How to show imageView full screen on imageView click?

use following property of ImageView for full size of image

 android:scaleType="fitXY"

ex :

      <ImageView
        android:id="@+id/tVHeader2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="fitXY"
        android:gravity="center"
        android:src="@drawable/done_sunheading" />

1)Switch on other activity when click on image.

2)pass url in intent

3)Take imageview on that Activity and set above property of imageview

4)Get the url from intent and set that image.

but using this your image may be starched if it will of small size.

How can I revert a single file to a previous version?

You can take a diff that undoes the changes you want and commit that.

E.g. If you want to undo the changes in the range from..to, do the following

git diff to..from > foo.diff  # get a reverse diff
patch < foo.diff
git commit -a -m "Undid changes from..to".

How can I remove the outline around hyperlinks images?

include this code in your style sheet

img {border : 0;}

a img {outline : none;}

Loading custom functions in PowerShell

You have to dot source them:

. .\build_funtions.ps1
. .\build_builddefs.ps1

Note the extra .

This heyscriptingguy article should be of help - How to Reuse Windows PowerShell Functions in Scripts

How to 'update' or 'overwrite' a python list

What about replace the item if you know the position:

aList[0]=2014

Or if you don't know the position loop in the list, find the item and then replace it

aList = [123, 'xyz', 'zara', 'abc']
    for i,item in enumerate(aList):
      if item==123:
        aList[i]=2014
        break
    
    print aList

Angularjs on page load call function

You should call this function from the controller.

angular.module('App', [])
  .controller('CinemaCtrl', ['$scope', function($scope) {
    myFunction();
  }]);

Even with normal javascript/html your function won't run on page load as all your are doing is defining the function, you never call it. This is really nothing to do with angular, but since you're using angular the above would be the "angular way" to invoke the function.

Obviously better still declare the function in the controller too.

Edit: Actually I see your "onload" - that won't get called as angular injects the HTML into the DOM. The html is never "loaded" (or the page is only loaded once).

pip cannot install anything

I used to use the easy_install pip==1.2.1 workaround but I randomly found that if you're having this bug, you probably installed a 32bit version of python on a 64bit machine.

In short : If you install a 64bit version of it by installing it from the source and then build your virtualenv upon it, you wont have that pip bug anymore.

Difference between spring @Controller and @RestController annotation

@Controller returns View. @RestController returns ResponseBody.

SQL JOIN and different types of JOINs

Definition:

JOINS are way to query the data that combined together from multiple tables simultaneously.

Types of JOINS:

Concern to RDBMS there are 5-types of joins:

Equi-Join: Combines common records from two tables based on equality condition. Technically, Join made by using equality-operator (=) to compare values of Primary Key of one table and Foreign Key values of another table, hence result set includes common(matched) records from both tables. For implementation see INNER-JOIN.
Natural-Join: It is enhanced version of Equi-Join, in which SELECT operation omits duplicate column. For implementation see INNER-JOIN
Non-Equi-Join: It is reverse of Equi-join where joining condition is uses other than equal operator(=) e.g, !=, <=, >=, >, < or BETWEEN etc. For implementation see INNER-JOIN.
Self-Join:: A customized behavior of join where a table combined with itself; This is typically needed for querying self-referencing tables (or Unary relationship entity). For implementation see INNER-JOINs.
Cartesian Product: It cross combines all records of both tables without any condition. Technically, it returns the result set of a query without WHERE-Clause.

As per SQL concern and advancement, there are 3-types of joins and all RDBMS joins can be achieved using these types of joins.

INNER-JOIN: It merges(or combines) matched rows from two tables. The matching is done based on common columns of tables and their comparing operation. If equality based condition then: EQUI-JOIN performed, otherwise Non-EQUI-Join.
OUTER-JOIN: It merges(or combines) matched rows from two tables and unmatched rows with NULL values. However, can customized selection of un-matched rows e.g, selecting unmatched row from first table or second table by sub-types: LEFT OUTER JOIN and RIGHT OUTER JOIN.

2.1. LEFT Outer JOIN (a.k.a, LEFT-JOIN): Returns matched rows from two tables and unmatched from the LEFT table(i.e, first table) only.

2.2. RIGHT Outer JOIN (a.k.a, RIGHT-JOIN): Returns matched rows from two tables and unmatched from the RIGHT table only.

2.3. FULL OUTER JOIN (a.k.a OUTER JOIN): Returns matched and unmatched from both tables.
CROSS-JOIN: This join does not merges/combines instead it performs Cartesian product.

enter image description here Note: Self-JOIN can be achieved by either INNER-JOIN, OUTER-JOIN and CROSS-JOIN based on requirement but the table must join with itself.

For more information:

Examples:

1.1: INNER-JOIN: Equi-join implementation

SELECT  *
FROM Table1 A 
 INNER JOIN Table2 B ON A.<Primary-Key> =B.<Foreign-Key>;

1.2: INNER-JOIN: Natural-JOIN implementation

Select A.*, B.Col1, B.Col2          --But no B.ForeignKeyColumn in Select
 FROM Table1 A
 INNER JOIN Table2 B On A.Pk = B.Fk;

1.3: INNER-JOIN with NON-Equi-join implementation

Select *
 FROM Table1 A INNER JOIN Table2 B On A.Pk <= B.Fk;

1.4: INNER-JOIN with SELF-JOIN

Select *
 FROM Table1 A1 INNER JOIN Table1 A2 On A1.Pk = A2.Fk;

2.1: OUTER JOIN (full outer join)

Select *
 FROM Table1 A FULL OUTER JOIN Table2 B On A.Pk = B.Fk;

2.2: LEFT JOIN

Select *
 FROM Table1 A LEFT OUTER JOIN Table2 B On A.Pk = B.Fk;

2.3: RIGHT JOIN

Select *
 FROM Table1 A RIGHT OUTER JOIN Table2 B On A.Pk = B.Fk;

3.1: CROSS JOIN

Select *
 FROM TableA CROSS JOIN TableB;

3.2: CROSS JOIN-Self JOIN

Select *
 FROM Table1 A1 CROSS JOIN Table1 A2;

//OR//

Select *
 FROM Table1 A1,Table1 A2;

Vue.js img src concatenate variable and text

just try

_x000D_

<img :src="require(`${imgPreUrl}img/logo.png`)">

_x000D_

Image encryption/decryption using AES256 symmetric block ciphers

Here is simple code snippet working for AES Encryption and Decryption.

import android.util.Base64;

import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;

public class AESEncryptionClass {

    private static String INIT_VECTOR_PARAM = "#####";
    private static String PASSWORD = "#####";
    private static String SALT_KEY = "#####";

    private static SecretKeySpec generateAESKey() throws NoSuchAlgorithmException, InvalidKeySpecException {

        // Prepare password and salt key.
        char[] password = new String(Base64.decode(PASSWORD, Base64.DEFAULT)).toCharArray();
        byte[] salt = new String(Base64.decode(SALT_KEY, Base64.DEFAULT)).getBytes(StandardCharsets.UTF_8);

        // Create object of  [Password Based Encryption Key Specification] with required iteration count and key length.
        KeySpec spec = new PBEKeySpec(password, salt, 64, 256);

        // Now create AES Key using required hashing algorithm.
        SecretKey key = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1").generateSecret(spec);

        // Get encoded bytes of secret key.
        byte[] bytesSecretKey = key.getEncoded();

        // Create specification for AES Key.
        SecretKeySpec secretKeySpec = new SecretKeySpec(bytesSecretKey, "AES");
        return secretKeySpec;
    }

    /**
     * Call this method to encrypt the readable plain text and get Base64 of encrypted bytes.
     */
    public static String encryptMessage(String message) throws BadPaddingException, IllegalBlockSizeException, NoSuchPaddingException, NoSuchAlgorithmException, UnsupportedEncodingException, InvalidKeySpecException, InvalidAlgorithmParameterException, InvalidKeyException {

        byte[] initVectorParamBytes = new String(Base64.decode(INIT_VECTOR_PARAM, Base64.DEFAULT)).getBytes(StandardCharsets.UTF_8);

        Cipher encryptionCipherBlock = Cipher.getInstance("AES/CBC/PKCS5Padding");
        encryptionCipherBlock.init(Cipher.ENCRYPT_MODE, generateAESKey(), new IvParameterSpec(initVectorParamBytes));

        byte[] messageBytes = message.getBytes();
        byte[] cipherTextBytes = encryptionCipherBlock.doFinal(messageBytes);
        String encryptedText = Base64.encodeToString(cipherTextBytes, Base64.DEFAULT);
        return encryptedText;
    }

    /**
     * Call this method to decrypt the Base64 of encrypted message and get readable plain text.
     */
    public static String decryptMessage(String base64Cipher) throws BadPaddingException, IllegalBlockSizeException, NoSuchPaddingException, NoSuchAlgorithmException, UnsupportedEncodingException, InvalidKeySpecException, InvalidAlgorithmParameterException, InvalidKeyException {

        byte[] initVectorParamBytes = new String(Base64.decode(INIT_VECTOR_PARAM, Base64.DEFAULT)).getBytes(StandardCharsets.UTF_8);

        Cipher decryptionCipherBlock = Cipher.getInstance("AES/CBC/PKCS5Padding");
        decryptionCipherBlock.init(Cipher.DECRYPT_MODE, generateAESKey(), new IvParameterSpec(initVectorParamBytes));

        byte[] cipherBytes = Base64.decode(base64Cipher, Base64.DEFAULT);
        byte[] messageBytes = decryptionCipherBlock.doFinal(cipherBytes);
        String plainText = new String(messageBytes);
        return plainText;
    }
}

Now, call encryptMessage() or decryptMessage() for desired AES Operation with required parameters.

Also, handle the exceptions during AES operations.

Hope it helped...

GetFiles with multiple extensions

I'm not sure if that is possible. The MSDN GetFiles reference says a search pattern, not a list of search patterns.

I might be inclined to fetch each list separately and "foreach" them into a final list.

.NET Core vs Mono

This is one of my favorite topics and the content here was just amazing. I was thinking if it would be worth while or effective to compare the methods available in Runtime vs. Mono. I hope I got my terms right, but I think you know what I mean. In order to have a somewhat better understanding of what each Runtime supports currently, would it make sense to compare the methods they provide? I realize implementations may vary, and I have not considered the Framework Class libraries or the slew of other libraries available in one environment vs. the other. I also realize someone might have already done this work even more efficiently. I would be most grateful if you would let me know so I can review it. I feel doing a diff between the outcome of such activity would be of value, and wanted to see how more experienced developers feel about it, and would they provide useful guidance. While back I was playing with reflection, and wrote some lines that traverse the .net directory, and list the assemblies.

Does java have a int.tryparse that doesn't throw an exception for bad data?

No. You have to make your own like this:

boolean tryParseInt(String value) {  
     try {  
         Integer.parseInt(value);  
         return true;  
      } catch (NumberFormatException e) {  
         return false;  
      }  
}

...and you can use it like this:

if (tryParseInt(input)) {  
   Integer.parseInt(input);  // We now know that it's safe to parse
}

EDIT (Based on the comment by @Erk)

Something like follows should be better

public int tryParse(String value, int defaultVal) {
    try {
        return Integer.parseInt(value);
    } catch (NumberFormatException e) {
        return defaultVal;
    }
}

When you overload this with a single string parameter method, it would be even better, which will enable using with the default value being optional.

public int tryParse(String value) {
    return tryParse(value, 0)
}

Java AES and using my own Key

import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.*;
import java.io.BufferedReader;
import java.io.FileReader;

public class AESFile 
{
private static String algorithm = "AES";
private static byte[] keyValue=new byte[] {'0','2','3','4','5','6','7','8','9','1','2','3','4','5','6','7'};// your key

    // Performs Encryption
    public static String encrypt(String plainText) throws Exception 
    {
            Key key = generateKey();
            Cipher chiper = Cipher.getInstance(algorithm);
            chiper.init(Cipher.ENCRYPT_MODE, key);
            byte[] encVal = chiper.doFinal(plainText.getBytes());
            String encryptedValue = new BASE64Encoder().encode(encVal);
            return encryptedValue;
    }

    // Performs decryption
    public static String decrypt(String encryptedText) throws Exception 
    {
            // generate key 
            Key key = generateKey();
            Cipher chiper = Cipher.getInstance(algorithm);
            chiper.init(Cipher.DECRYPT_MODE, key);
            byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedText);
            byte[] decValue = chiper.doFinal(decordedValue);
            String decryptedValue = new String(decValue);
            return decryptedValue;
    }

//generateKey() is used to generate a secret key for AES algorithm
    private static Key generateKey() throws Exception 
    {
            Key key = new SecretKeySpec(keyValue, algorithm);
            return key;
    }

    // performs encryption & decryption 
    public static void main(String[] args) throws Exception 
    {
        FileReader file = new FileReader("C://myprograms//plaintext.txt");
        BufferedReader reader = new BufferedReader(file);
        String text = "";
        String line = reader.readLine();
    while(line!= null)
        {
            text += line;
    line = reader.readLine();
        }
        reader.close();
    System.out.println(text);

            String plainText = text;
            String encryptedText = AESFile.encrypt(plainText);
            String decryptedText = AESFile.decrypt(encryptedText);

            System.out.println("Plain Text : " + plainText);
            System.out.println("Encrypted Text : " + encryptedText);
            System.out.println("Decrypted Text : " + decryptedText);
    }
}

What is Python used for?

Why should you learn Python Programming Language?

Python offers a stepping stone into the world of programming. Even though Python Programming Language has been around for 25 years, it is still rising in popularity. Some of the biggest advantage of Python are it's

Easy to Read & Easy to Learn
Very productive or small as well as big projects
Big libraries for many things

What is Python Programming Language used for?

As a general purpose programming language, Python can be used for multiple things. Python can be easily used for small, large, online and offline projects. The best options for utilizing Python are web development, simple scripting and data analysis. Below are a few examples of what Python will let you do:

Web Development:

You can use Python to create web applications on many levels of complexity. There are many excellent Python web frameworks including, Pyramid, Django and Flask, to name a few.

Data Analysis:

Python is the leading language of choice for many data scientists. Python has grown in popularity, within this field, due to its excellent libraries including; NumPy and Pandas and its superb libraries for data visualisation like Matplotlib and Seaborn.

Machine Learning:

What if you could predict customer satisfaction or analyse what factors will affect household pricing or to predict stocks over the next few days, based on previous years data? There are many wonderful libraries implementing machine learning algorithms such as Scikit-Learn, NLTK and TensorFlow.

Computer Vision:

You can do many interesting things such as Face detection, Color detection while using Opencv and Python.

Internet Of Things With Raspberry Pi:

Raspberry Pi is a very tiny and affordable computer which was developed for education and has gained enormous popularity among hobbyists with do-it-yourself hardware and automation. You can even build a robot and automate your entire home. Raspberry Pi can be used as the brain for your robot in order to perform various actions and/or react to the environment. The coding on a Raspberry Pi can be performed using Python. The Possibilities are endless!

Game Development:

Create a video game using module Pygame. Basically, you use Python to write the logic of the game. PyGame applications can run on Android devices.

Web Scraping:

If you need to grab data from a website but the site does not have an API to expose data, use Python to scraping data.

Writing Scripts:

If you're doing something manually and want to automate repetitive stuff, such as emails, it's not difficult to automate once you know the basics of this language.

Browser Automation:

Perform some neat things such as opening a browser and posting a Facebook status, you can do it with Selenium with Python.

GUI Development:

Build a GUI application (desktop app) using Python modules Tkinter, PyQt to support it.

Rapid Prototyping:

Python has libraries for just about everything. Use it to quickly built a (lower-performance, often less powerful) prototype. Python is also great for validating ideas or products for established companies and start-ups alike.

Python can be used in so many different projects. If you're a programmer looking for a new language, you want one that is growing in popularity. As a newcomer to programming, Python is the perfect choice for learning quickly and easily.

How to use ng-repeat without an html element

As of AngularJS 1.2 there's a directive called ng-repeat-start that does exactly what you ask for. See my answer in this question for a description of how to use it.

In a unix shell, how to get yesterday's date into a variable?

You can use GNU date command as shown below

Getting Date In the Past

To get yesterday and earlier day in the past use string day ago:

date --date='yesterday'

date --date='1 day ago'

date --date='10 day ago'

date --date='10 week ago'

date --date='10 month ago'

date --date='10 year ago'

Getting Date In the Future

To get tomorrow and day after tomorrow (tomorrow+N) use day word to get date in the future as follows:

date --date='tomorrow'

date --date='1 day'

date --date='10 day'

date --date='10 week'

date --date='10 month'

date --date='10 year'

Using G++ to compile multiple .cpp and .h files

I know this question has been asked years ago but still wanted to share how I usually compile multiple c++ files.

Let's say you have 5 cpp files, all you have to do is use the * instead of typing each cpp files name E.g g++ -c *.cpp -o myprogram.
This will generate "myprogram"
run the program ./myprogram

that's all!!

The reason I'm using * is that what if you have 30 cpp files would you type all of them? or just use the * sign and save time :)

p.s Use this method only if you don't care about makefile.

Generate a heatmap in MatPlotLib using a scatter data set

Seaborn now has the jointplot function which should work nicely here:

import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt

# Generate some test data
x = np.random.randn(8873)
y = np.random.randn(8873)

sns.jointplot(x=x, y=y, kind='hex')
plt.show()

ExecJS and could not find a JavaScript runtime

In your gem file Uncomment this line.

19 # gem 'therubyracer', platforms: :ruby

And run bundle install

You are ready to work. :)

Copy Image from Remote Server Over HTTP

You've got about these four possibilities:

Remote files. This needs allow_url_fopen to be enabled in php.ini, but it's the easiest method.
Alternatively you could use cURL if your PHP installation supports it. There's even an example.
And if you really want to do it manually use the HTTP module.
Don't even try to use sockets directly.

What is a regular expression which will match a valid domain name without a subdomain?

Not enough rep yet to comment. In response to paka's solution, I found I needed to adjust three items:

The dash and underscore were moved due to the dash being interpreted as a range (as in "0-9")
Added a full stop for domain names with many subdomains
Extended the potential length for the TLDs to 13

Before:

^(([a-zA-Z]{1})|([a-zA-Z]{1}[a-zA-Z]{1})|([a-zA-Z]{1}[0-9]{1})|([0-9]{1}[a-zA-Z]{1})|([a-zA-Z0-9][a-zA-Z0-9-_]{1,61}[a-zA-Z0-9]))\.([a-zA-Z]{2,6}|[a-zA-Z0-9-]{2,30}\.[a-zA-Z]{2,3})$

After:

^(([a-zA-Z]{1})|([a-zA-Z]{1}[a-zA-Z]{1})|([a-zA-Z]{1}[0-9]{1})|([0-9]{1}[a-zA-Z]{1})|([a-zA-Z0-9][-_\.a-zA-Z0-9]{1,61}[a-zA-Z0-9]))\.([a-zA-Z]{2,13}|[a-zA-Z0-9-]{2,30}\.[a-zA-Z]{2,3})$

top -c command in linux to filter processes listed based on processname

Most of the answers fail here, when process list exceeds 20 processes. That is top -p option limit. For those with older top that does not support filtering with o options, here is a scriptable example to get full screen/console outuput (summary information is missing from this output).

__keyword="YOUR_FILTER" ; ( FILL=""; for i in  $( seq 1 $(stty size|cut -f1 -d" ")); do FILL=$'\n'$FILL; done ;  while :; do HSIZE=$(( $(stty size|cut -f1 -d" ")  - 1 ));  (top -bcn1 | grep "$__keyword"; echo "$FILL" )|head -n$HSIZE; sleep 1;done )

Some explanations

__keyword = your grep filter keyword
HSIZE=console height
FILL=new lines to fill the screen if list is shorter than console height
top -bcn1 = batch, full commandline, repeat once

How do I restore a dump file from mysqldump?

Run the command to enter into the DB

 # mysql -u root -p

Enter the password for the user Then Create a New DB

mysql> create database MynewDB;
mysql> exit

And make exit.Afetr that.Run this Command

# mysql -u root -p  MynewDB < MynewDB.sql

Then enter into the db and type

mysql> show databases;
mysql> use MynewDB;
mysql> show tables;
mysql> exit

Thats it ........ Your dump will be restored from one DB to another DB

Or else there is an Alternate way for dump restore

# mysql -u root -p

Then enter into the db and type

mysql> create database MynewDB;
mysql> show databases;
mysql> use MynewDB;
mysql> source MynewDB.sql;
mysql> show tables;
mysql> exit

trim left characters in sql server?

select substring( field, 1, 5 ) from sometable

Make an existing Git branch track a remote branch?

To avoid remembering what you need to do each time you get the message:

Please specify which branch you want to merge with. See git-pull(1)
for details.
.....

You can use the following script which sets origin as upstream for the current branch you are in.

In my case I almost never set something else than origin as the default upstream. Also I almost always keep the same branch name for local and remote branch. So the following fits me:

#!/bin/bash
# scriptname: git-branch-set-originupstream
current_branch="$(git branch | grep -oP '(?<=^\* )(.*)$')"
upstream="origin/$current_branch"
git branch -u "$upstream"

CSS override rules and specificity

The important needs to be inside the ;

td.rule2 div {     background-color: #ffff00 !important; }

in fact i believe this should override it

td.rule2 { background-color: #ffff00 !important; }

How does strtok() split the string into tokens in C?

the strtok runtime function works like this

the first time you call strtok you provide a string that you want to tokenize

char s[] = "this is a string";

in the above string space seems to be a good delimiter between words so lets use that:

char* p = strtok(s, " ");

what happens now is that 's' is searched until the space character is found, the first token is returned ('this') and p points to that token (string)

in order to get next token and to continue with the same string NULL is passed as first argument since strtok maintains a static pointer to your previous passed string:

p = strtok(NULL," ");

p now points to 'is'

and so on until no more spaces can be found, then the last string is returned as the last token 'string'.

more conveniently you could write it like this instead to print out all tokens:

for (char *p = strtok(s," "); p != NULL; p = strtok(NULL, " "))
{
  puts(p);
}

EDIT:

If you want to store the returned values from strtok you need to copy the token to another buffer e.g. strdup(p); since the original string (pointed to by the static pointer inside strtok) is modified between iterations in order to return the token.

Get current URL/URI without some of $_GET variables

Yii 1

Yii::app()->request->url

For Yii2:

Yii::$app->request->url

How to set proper codeigniter base url?

If you leave it blank the framework will try to autodetect it since version 2.0.0.

But not in 3.0.0, see here: config.php

Execute write on doc: It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.

In case this is useful to anyone I had this same issue. I was bringing in a footer into a web page via jQuery. Inside that footer were some Google scripts for ads and retargeting. I had to move those scripts from the footer and place them directly in the page and that eliminated the notice.

Change bundle identifier in Xcode when submitting my first app in IOS

This solve my problem.

Just change the Bundle identifier from Build Setting.

 Navigate to Project >> Build Setting >> Product Bundle Identifier

How to replace all occurrences of a string in Javascript?

In November 2019 a new feature is added to the JavaScript string.prototype.replaceAll().

Currently it's only supported with babel.JS, but maybe in the future it can be implemented in all the browsers. For more information, read here.

Is null check needed before calling instanceof?

No, a null check is not needed before using instanceof.

The expression x instanceof SomeClass is false if x is null.

From the Java Language Specification, section 15.20.2, "Type comparison operator instanceof":

"At run time, the result of the instanceof operator is true if the value of the RelationalExpression is not null and the reference could be cast to the ReferenceType without raising a ClassCastException. Otherwise the result is false."

So if the operand is null, the result is false.

javax.servlet.ServletException cannot be resolved to a type in spring web app

I guess this may work, in Eclipse select your project ? then click on project menu bar on top ? goto to properties ? click on Targeted Runtimes ? now you must select a check box next to the server you are using to run current project ? click Apply ? then click OK button. That's it, give a try.

POST data to a URL in PHP

If you're looking to post data to a URL from PHP code itself (without using an html form) it can be done with curl. It will look like this:

$url = 'http://www.someurl.com';
$myvars = 'myvar1=' . $myvar1 . '&myvar2=' . $myvar2;

$ch = curl_init( $url );
curl_setopt( $ch, CURLOPT_POST, 1);
curl_setopt( $ch, CURLOPT_POSTFIELDS, $myvars);
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt( $ch, CURLOPT_HEADER, 0);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1);

$response = curl_exec( $ch );

This will send the post variables to the specified url, and what the page returns will be in $response.

How to use timer in C?

Yes, you need a loop. If you already have a main loop (most GUI event-driven stuff does) you can probably stick your timer into that. Use:

#include <time.h> 
time_t my_t, fire_t;

Then (for times over 1 second), initialize your timer by reading the current time:

my_t = time(NULL);

Add the number of seconds your timer should wait and store it in fire_t. A time_t is essentially a uint32_t, you may need to cast it.

Inside your loop do another

my_t = time(NULL);

if (my_t > fire_t) then consider the timer fired and do the stuff you want there. That will probably include resetting it by doing another fire_t = time(NULL) + seconds_to_wait for next time.

A time_t is a somewhat antiquated unix method of storing time as the number of seconds since midnight 1/1/1970 but it has many advantages. For times less than 1 second you need to use gettimeofday() (microseconds) or clock_gettime() (nanoseconds) and deal with a struct timeval or struct timespec which is a time_t and the microseconds or nanoseconds since that 1 second mark. Making a timer works the same way except when you add your time to wait you need to remember to manually do the carry (into the time_t) if the resulting microseconds or nanoseconds value goes over 1 second. Yes, it's messy. See man 2 time, man gettimeofday, man clock_gettime.

sleep(), usleep(), nanosleep() have a hidden benefit. You see it as pausing your program, but what they really do is release the CPU for that amount of time. Repeatedly polling by reading the time and comparing to the done time (are we there yet?) will burn a lot of CPU cycles which may slow down other programs running on the same machine (and use more electricity/battery). It's better to sleep() most of the time then start checking the time.

If you're trying to sleep and do work at the same time you need threads.

Error: the entity type requires a primary key

This worked for me:

using System.ComponentModel.DataAnnotations;

[Key]
public int ID { get; set; }

Spring: How to inject a value to static field?

Spring uses dependency injection to populate the specific value when it finds the @Value annotation. However, instead of handing the value to the instance variable, it's handed to the implicit setter instead. This setter then handles the population of our NAME_STATIC value.

    @RestController 
//or if you want to declare some specific use of the properties file then use
//@Configuration
//@PropertySource({"classpath:application-${youeEnvironment}.properties"})
public class PropertyController {

    @Value("${name}")//not necessary
    private String name;//not necessary

    private static String NAME_STATIC;

    @Value("${name}")
    public void setNameStatic(String name){
        PropertyController.NAME_STATIC = name;
    }
}

Jquery: Find Text and replace

Warning string.replace('string','new string') not replaced all character. You have to use regax replace.

For exp: I have a sting old string1, old string2, old string3 and want to replace old to new

Then i used.

    var test = 'old string1, old string2, old string3';

   //***** Wrong method **********
    test = test.replace('old', 'new'); // This  will replaced only first match not all
    Result: new string1, old string2, old string3

  //***** Right method **********
    test = test.replace(/([old])+/g, 'new'); // This  will replaced all match 
    Result: new string1, new string2, new string3

How to order results with findBy() in Doctrine

$cRepo = $em->getRepository('KaleLocationBundle:Country');

// Leave the first array blank
$countries = $cRepo->findBy(array(), array('name'=>'asc'));

How to load npm modules in AWS Lambda?

Hope this helps, with Serverless framework you can do something like this:

Add these things in your serverless.yml file:

plugins: - serverless-webpack custom: webpackIncludeModules: forceInclude: - <your package name> (for example: node-fetch) 2. Then create your Lambda function, deploy it by serverless deploy, the package that included in serverless.yml will be there for you.

For more information about serverless: https://serverless.com/framework/docs/providers/aws/guide/quick-start/

Way to get number of digits in an int?

Can I try? ;)

based on Dirk's solution

final int digits = number==0?1:(1 + (int)Math.floor(Math.log10(Math.abs(number))));

Is it possible to use JS to open an HTML select to show its option list?

This works on Google Chrome

dropDown = function (elementId) {
    var dropdown = document.getElementById(elementId);
    try {
        showDropdown(dropdown);
    } catch(e) {

    }
    return false;
};

showDropdown = function (element) {
    var event;
    event = document.createEvent('MouseEvents');
    event.initMouseEvent('mousedown', true, true, window);
    element.dispatchEvent(event);
};

Insert an item into sorted list in Python

Hint 1: You might want to study the Python code in the bisect module.

Hint 2: Slicing can be used for list insertion:

>>> s = ['a', 'b', 'd', 'e']
>>> s[2:2] = ['c']
>>> s
['a', 'b', 'c', 'd', 'e']

Get Substring between two characters using javascript

var s = 'MyLongString:StringIWant;';
/:([^;]+);/.exec(s)[1]; // StringIWant

MySQL show status - active or total connections?

As per doc http://dev.mysql.com/doc/refman/5.0/en/server-status-variables.html#statvar_Connections

Connections

The number of connection attempts (successful or not) to the MySQL server.

What is the most efficient/elegant way to parse a flat table into a tree?

If elements are in tree order, as shown in your example, you can use something like the following Python example:

delimiter = '.'
stack = []
for item in items:
  while stack and not item.startswith(stack[-1]+delimiter):
    print "</div>"
    stack.pop()
  print "<div>"
  print item
  stack.append(item)

What this does is maintain a stack representing the current position in the tree. For each element in the table, it pops stack elements (closing the matching divs) until it finds the parent of the current item. Then it outputs the start of that node and pushes it to the stack.

If you want to output the tree using indenting rather than nested elements, you can simply skip the print statements to print the divs, and print a number of spaces equal to some multiple of the size of the stack before each item. For example, in Python:

print "  " * len(stack)

You could also easily use this method to construct a set of nested lists or dictionaries.

Edit: I see from your clarification that the names were not intended to be node paths. That suggests an alternate approach:

idx = {}
idx[0] = []
for node in results:
  child_list = []
  idx[node.Id] = child_list
  idx[node.ParentId].append((node, child_list))

This constructs a tree of arrays of tuples(!). idx[0] represents the root(s) of the tree. Each element in an array is a 2-tuple consisting of the node itself and a list of all its children. Once constructed, you can hold on to idx[0] and discard idx, unless you want to access nodes by their ID.

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

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

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

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

after that, Run

aspnet_regiis.exe -i -enable

and Finally Reset IIS

iisreset

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

android.content.Context.getPackageName()' on a null object reference

My class is not extends to Activiti. I solved the problem this way.

class MyOnBindViewHolder : LogicViewAdapterModel.LogicAdapter {
          ...
 holder.title.setOnClickListener({v->
                v.context.startActivity(Intent(context,  HomeActivity::class.java))
            })
          ...
    }

How can I access an internal class from an external assembly?

I would like to argue one point - that you cannot augment the original assembly - using Mono.Cecil you can inject [InternalsVisibleTo(...)] to the 3pty assembly. Note there might be legal implications - you're messing with 3pty assembly and technical implications - if the assembly has strong name you either need to strip it or re-sign it with different key.

 Install-Package Mono.Cecil

And the code like:

static readonly string[] s_toInject = {
  // alternatively "MyAssembly, PublicKey=0024000004800000... etc."
  "MyAssembly"
};

static void Main(string[] args) {
  const string THIRD_PARTY_ASSEMBLY_PATH = @"c:\folder\ThirdPartyAssembly.dll";

   var parameters = new ReaderParameters();
   var asm = ModuleDefinition.ReadModule(INPUT_PATH, parameters);
   foreach (var toInject in s_toInject) {
     var ca = new CustomAttribute(
       asm.Import(typeof(InternalsVisibleToAttribute).GetConstructor(new[] {
                      typeof(string)})));
     ca.ConstructorArguments.Add(new CustomAttributeArgument(asm.TypeSystem.String, toInject));
     asm.Assembly.CustomAttributes.Add(ca);
   }
   asm.Write(@"c:\folder-modified\ThirdPartyAssembly.dll");
   // note if the assembly is strongly-signed you need to resign it like
   // asm.Write(@"c:\folder-modified\ThirdPartyAssembly.dll", new WriterParameters {
   //   StrongNameKeyPair = new StrongNameKeyPair(File.ReadAllBytes(@"c:\MyKey.snk"))
   // });
}

Calling jQuery method from onClick attribute in HTML

I know this was answered long ago, but if you don't mind creating the button dynamically, this works using only the jQuery framework:

_x000D_

$(document).ready(function() {_x000D_
  $button = $('<input id="1" type="button" value="ahaha" />');_x000D_
  $('body').append($button);_x000D_
  $button.click(function() {_x000D_
    console.log("Id clicked: " + this.id ); // or $(this) or $button_x000D_
  });_x000D_
});

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<p>And here is my HTML page:</p>_x000D_
_x000D_
<div class="Title">Welcome!</div>

_x000D_

Add a pipe separator after items in an unordered list unless that item is the last on a line

I came across a solution today that does not appear to be here already and which seems to work quite well so far. The accepted answer does not work as-is on IE10 but this one does. http://codepen.io/vithun/pen/yDsjf/ credit to the author of course!

_x000D_

.pipe-separated-list-container {_x000D_
  overflow-x: hidden;_x000D_
}_x000D_
.pipe-separated-list-container ul {_x000D_
  list-style-type: none;_x000D_
  position: relative;_x000D_
  left: -1px;_x000D_
  padding: 0;_x000D_
}_x000D_
.pipe-separated-list-container ul li {_x000D_
  display: inline-block;_x000D_
  line-height: 1;_x000D_
  padding: 0 1em;_x000D_
  margin-bottom: 1em;_x000D_
  border-left: 1px solid;_x000D_
}

_x000D_

<div class="pipe-separated-list-container">_x000D_
  <ul>_x000D_
    <li>One</li>_x000D_
    <li>Two</li>_x000D_
    <li>Three</li>_x000D_
    <li>Four</li>_x000D_
    <li>Five</li>_x000D_
    <li>Six</li>_x000D_
    <li>Seven</li>_x000D_
    <li>Eight</li>_x000D_
    <li>Nine</li>_x000D_
    <li>Ten</li>_x000D_
    <li>Eleven</li>_x000D_
    <li>Twelve</li>_x000D_
    <li>Thirteen</li>_x000D_
    <li>Fourteen</li>_x000D_
    <li>Fifteen</li>_x000D_
    <li>Sixteen</li>_x000D_
    <li>Seventeen</li>_x000D_
    <li>Eighteen</li>_x000D_
    <li>Nineteen</li>_x000D_
    <li>Twenty</li>_x000D_
    <li>Twenty One</li>_x000D_
    <li>Twenty Two</li>_x000D_
    <li>Twenty Three</li>_x000D_
    <li>Twenty Four</li>_x000D_
    <li>Twenty Five</li>_x000D_
    <li>Twenty Six</li>_x000D_
    <li>Twenty Seven</li>_x000D_
    <li>Twenty Eight</li>_x000D_
    <li>Twenty Nine</li>_x000D_
    <li>Thirty</li>_x000D_
  </ul>_x000D_
</div>

_x000D_

What are the First and Second Level caches in (N)Hibernate?

1.1) First-level cache

First-level cache always Associates with the Session object. Hibernate uses this cache by default. Here, it processes one transaction after another one, means wont process one transaction many times. Mainly it reduces the number of SQL queries it needs to generate within a given transaction. That is instead of updating after every modification done in the transaction, it updates the transaction only at the end of the transaction.

1.2) Second-level cache

Second-level cache always associates with the Session Factory object. While running the transactions, in between it loads the objects at the Session Factory level, so that those objects will be available to the entire application, not bound to single user. Since the objects are already loaded in the cache, whenever an object is returned by the query, at that time no need to go for a database transaction. In this way the second level cache works. Here we can use query level cache also.

Quoted from: http://javabeat.net/introduction-to-hibernate-caching/

Make just one slide different size in Powerpoint

True you can't have different sized slides. NOT true the size of you slide doesn't matter. It will size it to your resolution, but you can click on the magnifying icon(at least on PP 2013) and you can then scroll in all directions of your slide in original resolution.

How to insert Records in Database using C# language?

You should form the command with the contents of the textboxes:

sql = "insert into Main (Firt Name, Last Name) values(" + textbox2.Text + "," + textbox3.Text+ ")";

This, of course, provided that you manage to open the connection correctly.

It would be helpful to know what's happening with your current code. If you are getting some error displayed in that message box, it would be great to know what it's saying.

You should also validate the inputs before actually running the command (i.e. make sure they don't contain malicious code...).

Standardize data columns in R

This is 3 years old. Still, I feel I have to add the following:

The most common normalization is the z-transformation, where you subtract the mean and divide by the standard deviation of your variable. The result will have mean=0 and sd=1.

For that, you don't need any package.

zVar <- (myVar - mean(myVar)) / sd(myVar)

That's it.

How to redirect to previous page in Ruby On Rails?

Why does redirect_to(:back) not work for you, why is it a no go?

redirect_to(:back) works like a charm for me. It's just a short cut for redirect_to(request.env['HTTP_REFERER'])

http://apidock.com/rails/ActionController/Base/redirect_to (pre Rails 3) or http://apidock.com/rails/ActionController/Redirecting/redirect_to (Rails 3)

Please note that redirect_to(:back) is being deprecated in Rails 5. You can use

redirect_back(fallback_location: 'something') instead (see http://blog.bigbinary.com/2016/02/29/rails-5-improves-redirect_to_back-with-redirect-back.html)

AngularJS Uploading An Image With ng-upload

In my case above mentioned methods work fine with php but when i try to upload files with these methods in node.js then i have some problem. So instead of using $http({..,..,...}) use the normal jquery ajax.

For select file use this

<input type="file" name="file" onchange="angular.element(this).scope().uploadFile(this)"/>

And in controller

$scope.uploadFile = function(element) {   
var data = new FormData();
data.append('file', $(element)[0].files[0]);
jQuery.ajax({
      url: 'brand/upload',
      type:'post',
      data: data,
      contentType: false,
      processData: false,
      success: function(response) {
      console.log(response);
      },
      error: function(jqXHR, textStatus, errorMessage) {
      alert('Error uploading: ' + errorMessage);
      }
 });   
};

ORA-01461: can bind a LONG value only for insert into a LONG column-Occurs when querying

It can also happen with varchar2 columns. This is pretty reproducible with PreparedStatements through JDBC by simply

creating a table with a column of varchar2 (20 or any arbitrary length) and
inserting into the above table with a row containing more than 20 characters

So as above said it can be wrong with types, or column width exceeded.

Also note that as varchar2 allows 4k chars max, the real limit will be 2k for double byte chars

Hope this helps

Paste in insert mode?

You can also use the mouse middle button to paste in insert mode (Linux only).

Is it possible to make desktop GUI application in .NET Core?

You could develop a web application with .NET Core and MVC and encapsulate it in a Windows universal JavaScript app: Progressive Web Apps on Windows

It is still a web application, but it's a very lightweight way to transform a web application into a desktop app without learning a new framework or/and redevelop the UI, and it works great.

The inconvenience is unlike Electron or ReactXP for example, the result is a universal Windows application and not a cross platform desktop application.

MySQL - Selecting data from multiple tables all with same structure but different data

Any of the above answers are valid, or an alternative way is to expand the table name to include the database name as well - eg:

SELECT * from us_music, de_music where `us_music.genre` = 'punk' AND `de_music.genre` = 'punk'

How to select multiple files with <input type="file">?

Copy and paste this into your html:

<input type="file" id="files" name="files[]" multiple />
<output id="list"></output>

<script>
function handleFileSelect(evt) {
var files = evt.target.files; // FileList object

// files is a FileList of File objects. List some properties.
var output = [];
for (var i = 0, f; f = files[i]; i++) {
  output.push('<li><strong>', escape(f.name), '</strong> (', f.type || 'n/a', ') - ',
              f.size, ' bytes, last modified: ',
              f.lastModifiedDate ? f.lastModifiedDate.toLocaleDateString() : 'n/a',
              '</li>');
}
document.getElementById('list').innerHTML = '<ul>' + output.join('') + '</ul>';
}

This comes to you, through me, from this webpage: http://www.html5rocks.com/en/tutorials/file/dndfiles/

center MessageBox in parent form

From a comment on Joel Spolsky's blog:

A Messagebox is always centered on the screen. You can provide an owner, but that is just for Z-order, not centering. The only way is to use Win32 hooks and center it yourself. You can find code doing that online if you search for it.

Much easier is to just write your own message box class and add centering functionality. Then you can also add default captioning, Do not show again-checkbox and making them modeless.

"Win32 hooks" probably refers to using SetWindowsHookEx as shown in this example.

How to use icons and symbols from "Font Awesome" on Native Android Application

I'm a bit late to the party but I wrote a custom view that let's you do this, by default it's set to entypo, but you can modify it to use any iconfont: check it out here: github.com/MarsVard/IconView

// edit the library is old and not supported anymore... new one here https://github.com/MarsVard/IonIconView

"implements Runnable" vs "extends Thread" in Java

Separating the Thread class from the Runnable implementation also avoids potential synchronization problems between the thread and the run() method. A separate Runnable generally gives greater flexibility in the way that runnable code is referenced and executed.

What is <scope> under <dependency> in pom.xml for?

.pom dependency scope can contain:

compile - available at Compile-time and Run-time
provided - available at Compile-time. (this dependency should be provided by outer container like OS...)
runtime - available at Run-time
test - test compilation and run time
system - is similar to provided but exposes <systemPath>path/some.jar</systemPath> to point on .jar
import - is available from Maven v2.0.9 for <type>pom</type> and it should be replaced by effective dependency from this file <dependencyManagement/>

Count table rows

If you have a primary key or a unique key/index, the faster method possible (Tested with 4 millions row tables)

SHOW INDEXES FROM "database.tablename" WHERE Key_Name=\"PRIMARY\"

and then get cardinality field (it is close to instant)

Times where from 0.4s to 0.0001ms

How do I center text vertically and horizontally in Flutter?

I think a more flexible option would be to wrap the Text() with Align() like so:

Align(
  alignment: Alignment.center, // Align however you like (i.e .centerRight, centerLeft)
  child: Text("My Text"),
),

Using Center() seems to ignore TextAlign entirely on the Text widget. It will not align TextAlign.left or TextAlign.right if you try, it will remain in the center.

NULL values inside NOT IN clause

SQL uses three-valued logic for truth values. The IN query produces the expected result:

SELECT * FROM (VALUES (1), (2)) AS tbl(col) WHERE col IN (NULL, 1)
-- returns first row

But adding a NOT does not invert the results:

SELECT * FROM (VALUES (1), (2)) AS tbl(col) WHERE NOT col IN (NULL, 1)
-- returns zero rows

This is because the above query is equivalent of the following:

SELECT * FROM (VALUES (1), (2)) AS tbl(col) WHERE NOT (col = NULL OR col = 1)

Here is how the where clause is evaluated:

| col | col = NULL?¹?  | col = 1 | col = NULL OR col = 1 | NOT (col = NULL OR col = 1) |
|-----|----------------|---------|-----------------------|-----------------------------|
| 1   | UNKNOWN        | TRUE    | TRUE                  | FALSE                       |
| 2   | UNKNOWN        | FALSE   | UNKNOWN?²?            | UNKNOWN?³?                  |

Notice that:

The comparison involving NULL yields UNKNOWN
The OR expression where none of the operands are TRUE and at least one operand is UNKNOWN yields UNKNOWN (ref)
The NOT of UNKNOWN yields UNKNOWN (ref)

You can extend the above example to more than two values (e.g. NULL, 1 and 2) but the result will be same: if one of the values is NULL then no row will match.

What version of javac built my jar?

To expand on Jonathon Faust's and McDowell's answers: If you're on a *nix based system, you can use od (one of the earliest Unix programs¹ which should be available practically everywhere) to query the .class file on a binary level:

od -An -j7 -N1 -t dC SomeClassFile.class

This will output the familiar integer values, e.g. 50 for Java 5, 51 for Java 6 and so on.

¹ Quote from https://en.wikipedia.org/wiki/Od_(Unix)

CSS "color" vs. "font-color"

I would think that one reason could be that the color is applied to things other than font. For example:

div {
    border: 1px solid;
    color: red;
}

Yields both a red font color and a red border.

Alternatively, it could just be that the W3C's CSS standards are completely backwards and nonsensical as evidenced elsewhere.

How do I use a pipe to redirect the output of one command to the input of another?

Not sure if you are coding these programs, but this is a simple example of how you'd do it.

program1.c

#include <stdio.h>
int main (int argc, char * argv[] ) {
    printf("%s", argv[1]); 
    return 0;
}

rgx.cpp

#include <cstdio>
#include <regex>
#include <iostream>
using namespace std;
int main (int argc, char * argv[] ) {
    char input[200];
    fgets(input,200,stdin);
    string s(input)
    smatch m;
    string reg_exp(argv[1]);
    regex e(reg_exp);
    while (regex_search (s,m,e)) {
      for (auto x:m) cout << x << " ";
      cout << endl;
      s = m.suffix().str();
    }
    return 0;
}

Compile both then run program1.exe "this subject has a submarine as a subsequence" | rgx.exe "\b(sub)([^ ]*)"

The | operator simply redirects the output of program1's printf operation from the stdout stream to the stdin stream whereby it's sitting there waiting for rgx.exe to pick up.

In STL maps, is it better to use map::insert than []?

If the performance hit of the default constructor isn't an issue, the please, for the love of god, go with the more readable version.

How do I insert multiple checkbox values into a table?

You should specify

<input type="checkbox" name="Days[]" value="Daily">Daily<br>

as array.

Add [] to all names Days and work at php with this like an array.

After it, you can INSERT values at different columns at db, or use implode and save values into one column.

Didn't tested it, but you can try like this. Don't forget to replace mysql with mysqli.

<html>
<body>
<form method="post" action="chk123.php">
Flights on: <br/>
<input type="checkbox" name="Days[]" value="Daily">Daily<br>
<input type="checkbox" name="Days[]" value="Sunday">Sunday<br>
<input type="checkbox" name="Days[]" value="Monday">Monday<br>
<input type="checkbox" name="Days[]" value="Tuesday">Tuesday <br>
<input type="checkbox" name="Days[]" value="Wednesday">Wednesday<br>
<input type="checkbox" name="Days[]" value="Thursday">Thursday <br>
<input type="checkbox" name="Days[]" value="Friday">Friday<br>
<input type="checkbox" name="Days[]" value="Saturday">Saturday <br>
<input type="submit" name="submit" value="submit">
</form>
</body>
</html>

<?php

// Make a MySQL Connection
mysql_connect("localhost", "root", "") or die(mysql_error());
mysql_select_db("test") or die(mysql_error());

$checkBox = implode(',', $_POST['Days']);

if(isset($_POST['submit']))
{       
    $query="INSERT INTO example (orange) VALUES ('" . $checkBox . "')";     

    mysql_query($query) or die (mysql_error() );

    echo "Complete";

}

?>

Can I set variables to undefined or pass undefined as an argument?

I'm a bit confused about Javascript undefined & null.

null generally behaves similarly to other scripting languages' concepts of the out-of-band ‘null’, ‘nil’ or ‘None’ objects.

undefined, on the other hand, is a weird JavaScript quirk. It's a singleton object that represents out-of-band values, essentially a second similar-but-different null. It comes up:

When you call a function with fewer arguments than the arguments list in the function statement lists, the unpassed arguments are set to undefined. You can test for that with eg.:
```
function dosomething(arg1, arg2) {
    if (arg2===undefined)
    arg2= DEFAULT_VALUE_FOR_ARG2;
    ...
}
```
With this method you can't tell the difference between dosomething(1) and dosomething(1, undefined); arg2 will be the same value in both. If you need to tell the difference you can look at arguments.length, but doing optional arguments like that isn't generally very readable.
When a function has no return value;, it returns undefined. There's generally no need to use such a return result.
When you declare a variable by having a var a statement in a block, but haven't yet assigned a value to it, it is undefined. Again, you shouldn't really ever need to rely on that.
The spooky typeof operator returns 'undefined' when its operand is a simple variable that does not exist, instead of throwing an error as would normally happen if you tried to refer to it. (You can also give it a simple variable wrapped in parentheses, but not a full expression involving a non-existant variable.) Not much use for that, either.
This is the controversial one. When you access a property of an object which doesn't exist, you don't immediately get an error like in every other language. Instead you get an undefined object. (And then when you try to use that undefined object later on in the script it'll go wrong in a weird way that's much more difficult to track down than if JavaScript had just thrown an error straight away.)

This is often used to check for the existence of properties:
```
if (o.prop!==undefined) // or often as truthiness test, if (o.prop)
   ...do something...
```
However, because you can assign undefined like any other value:
```
o.prop= undefined;
```
that doesn't actually detect whether the property is there reliably. Better to use the in operator, which wasn't in the original Netscape version of JavaScript, but is available everywhere now:
```
if ('prop' in o)
    ...
```

In summary, undefined is a JavaScript-specific mess, which confuses everyone. Apart from optional function arguments, where JS has no other more elegant mechanism, undefined should be avoided. It should never have been part of the language; null would have worked just fine for (2) and (3), and (4) is a misfeature that only exists because in the beginning JavaScript had no exceptions.

what does if (!testvar) actually do? Does it test for undefined and null or just undefined?

Such a ‘truthiness’ test checks against false, undefined, null, 0, NaN and empty strings. But in this case, yes, it is really undefined it is concerned with. IMO, it should be more explicit about that and say if (testvar!==undefined).

once a variable is defined can I clear it back to undefined (therefore deleting the variable).

You can certainly assign undefined to it, but that won't delete the variable. Only the delete object.property operator really removes things.

delete is really meant for properties rather than variables as such. Browsers will let you get away with straight delete variable, but it's not a good idea and won't work in ECMAScript Fifth Edition's strict mode. If you want to free up a reference to something so it can be garbage-collected, it would be more usual to say variable= null.

can I pass undefined as a parameter?

Yes.

How to open CSV file in R when R says "no such file or directory"?

Kindly check whether the file name has an extension for example:
```
abc.csv
```
if so remove the .csv extension.
set wd to the folder containing the file (~)
data<-read.csv("abc.csv")

Your data has been read the data object

Using SQL LOADER in Oracle to import CSV file

Try this

load data infile 'datafile location' into table schema.tablename fields terminated by ',' optionally enclosed by '|' (field1,field2,field3....)

In command prompt:

sqlldr system@databasename/password control='control file location'

Uncaught SyntaxError: Unexpected token with JSON.parse

It seems you want to stringify the object. So do this:

JSON.stringify(products);

The reason for the error is that JSON.parse() expects a String value and products is an Array.

Note: I think it attempts json.parse('[object Array]') which complains it didn't expect token o after [.

getElementById returns null?

Also be careful how you execute the js on the page. For example if you do something like this:

(function(window, document, undefined){

  var foo = document.getElementById("foo");

  console.log(foo);

})(window, document, undefined);

This will return null because you'd be calling the document before it was loaded.

Better option..

(function(window, document, undefined){

// code that should be taken care of right away

window.onload = init;

  function init(){
    // the code to be called when the dom has loaded
    // #document has its nodes
  }

})(window, document, undefined);

What's onCreate(Bundle savedInstanceState)

As Dhruv Gairola answered, you can save the state of the application by using Bundle savedInstanceState. I am trying to give a very simple example that new learners like me can understand easily.

Suppose, you have a simple fragment with a TextView and a Button. Each time you clicked the button the text changes. Now, change the orientation of you device/emulator and notice that you lost the data (means the changed data after clicking you got) and fragment starts as the first time again. By using Bundle savedInstanceState we can get rid of this. If you take a look into the life cyle of the fragment.Fragment Lifecylce you will get that a method "onSaveInstanceState" is called when the fragment is about to destroyed.

So, we can save the state means the changed text value into that bundle like this

 int counter  = 0;
 @Override
 public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("value",counter);
 }

After you make the orientation the "onCreate" method will be called right? so we can just do this

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if(savedInstanceState == null){
        //it is the first time the fragment is being called
        counter = 0;
    }else{
        //not the first time so we will check SavedInstanceState bundle
        counter = savedInstanceState.getInt("value",0); //here zero is the default value
    }
}

Now, you won't lose your value after the orientation. The modified value always will be displayed.

Change Text Color of Selected Option in a Select Box

You could do it like this.

jsFiddle

var select = document.getElementById('mySelect');
select.onchange = function () {
    select.className = this.options[this.selectedIndex].className;
}

CSS

.redText {
    background-color:#F00;
}
.greenText {
    background-color:#0F0;
}
.blueText {
    background-color:#00F;
}

You could use option { background-color: #FFF; } if you want the list to be white.

HTML

<select id="mySelect" class="greenText">
    <option class="greenText" value="apple" >Apple</option>
    <option class="redText"   value="banana" >Banana</option>
    <option class="blueText" value="grape" >Grape</option>
</select>

Since this is a select it doesn't really make sense to use .yellowText as none selected if that's what you were getting at as something must be selected.

Bash syntax error: unexpected end of file

I had the problem when I wrote "if - fi" statement in one line:

if [ -f ~/.git-completion.bash ]; then . ~/.git-completion.bash fi

Write multiline solved my problem:

if [ -f ~/.git-completion.bash ]; then 
    . ~/.git-completion.bash
 fi

Swift 3 - Comparing Date objects

Another way to do it:

    switch date1.compare(date2) {
        case .orderedAscending:
            break

        case .orderedDescending:
            break;

        case .orderedSame:
            break
    }

Is it good practice to use the xor operator for boolean checks?

You can simply use != instead.

Backup a single table with its data from a database in sql server 2008

To get a copy in a file on the local file-system, this rickety utility from the Windows start button menu worked: "C:\Program Files (x86)\Microsoft SQL Server\110\DTS\Binn\DTSWizard.exe"

grid controls for ASP.NET MVC?

If it is read-only a good idea would be to create a table, then apply some really easy-but-powerful JQuery to that.

For simple alternative colour, try this simple JQuery.

If you need sorting, this JQuery plug-in simply rocks.

catch forEach last iteration

The 2018 ES6+ ANSWER IS:

    const arr = [1, 2, 3];

    arr.forEach((val, key, arr) => {
      if (Object.is(arr.length - 1, key)) {
        // execute last item logic
        console.log(`Last callback call at index ${key} with value ${val}` ); 
      }
    });

Eclipse Java error: This selection cannot be launched and there are no recent launches

click on the project that you want to run on the left side in package explorer and then click the Run button.

Is it possible to output a SELECT statement from a PL/SQL block?

From an anonymous block? I'd like to now more about the situation where you think that to be required, because with subquery factoring clauses and inline views it's pretty rare that you need to resort to PL/SQL for anything other than the most complex situations.

If you can use a named procedure then use pipelined functions. Here's an example pulled from the documentation:

CREATE PACKAGE pkg1 AS
  TYPE numset_t IS TABLE OF NUMBER;
  FUNCTION f1(x NUMBER) RETURN numset_t PIPELINED;
END pkg1;
/

CREATE PACKAGE BODY pkg1 AS
-- FUNCTION f1 returns a collection of elements (1,2,3,... x)
FUNCTION f1(x NUMBER) RETURN numset_t PIPELINED IS
  BEGIN
    FOR i IN 1..x LOOP
      PIPE ROW(i);
    END LOOP;
    RETURN;
  END;
END pkg1;
/

-- pipelined function is used in FROM clause of SELECT statement
SELECT * FROM TABLE(pkg1.f1(5));

How do I use tools:overrideLibrary in a build.gradle file?

use this code in manifest.xml

<uses-sdk
android:minSdkVersion="16"
android:maxSdkVersion="17"
tools:overrideLibrary="x"/>

SOAP or REST for Web Services?

REST is a fundamentally different paradigm from SOAP. A good read on REST can be found here: How I explained REST to my wife.

If you don't have time to read it, here's the short version: REST is a bit of a paradigm shift by focusing on "nouns", and restraining the number of "verbs" you can apply to those nouns. The only allowed verbs are "get", "put", "post" and "delete". This differs from SOAP where many different verbs can be applied to many different nouns (i.e. many different functions).

For REST, the four verbs map to the corresponding HTTP requests, while the nouns are identified by URLs. This makes state management much more transparent than in SOAP, where its often unclear what state is on the server and what is on the client.

In practice though most of this falls away, and REST usually just refers to simple HTTP requests that return results in JSON, while SOAP is a more complex API that communicates by passing XML around. Both have their advantages and disadvantages, but I've found that in my experience REST is usually the better choice because you rarely if ever need the full functionality you get from SOAP.

How can I make a JUnit test wait?

You could also use the CountDownLatch object like explained here.

How to remove all listeners in an element?

Here's a function that is also based on cloneNode, but with an option to clone only the parent node and move all the children (to preserve their event listeners):

function recreateNode(el, withChildren) {
  if (withChildren) {
    el.parentNode.replaceChild(el.cloneNode(true), el);
  }
  else {
    var newEl = el.cloneNode(false);
    while (el.hasChildNodes()) newEl.appendChild(el.firstChild);
    el.parentNode.replaceChild(newEl, el);
  }
}

Remove event listeners on one element:

recreateNode(document.getElementById("btn"));

Remove event listeners on an element and all of its children:

recreateNode(document.getElementById("list"), true);

If you need to keep the object itself and therefore can't use cloneNode, then you have to wrap the addEventListener function and track the listener list by yourself, like in this answer.

How to find specific lines in a table using Selenium?

if you want to access table cell

WebElement thirdCell = driver.findElement(By.Xpath("//table/tbody/tr[2]/td[1]"));

If you want to access nested table cell -

WebElement thirdCell = driver.findElement(By.Xpath("//table/tbody/tr[2]/td[2]"+//table/tbody/tr[1]/td[2]));

For more details visit this Tutorial

How to compare two List<String> to each other?

You could also use Except(produces the set difference of two sequences) to check whether there's a difference or not:

IEnumerable<string> inFirstOnly = a1.Except(a2);
IEnumerable<string> inSecondOnly = a2.Except(a1);
bool allInBoth = !inFirstOnly.Any() && !inSecondOnly.Any();

So this is an efficient way if the order and if the number of duplicates does not matter(as opposed to the accepted answer's SequenceEqual). Demo: Ideone

If you want to compare in a case insentive way, just add StringComparer.OrdinalIgnoreCase:

a1.Except(a2, StringComparer.OrdinalIgnoreCase)

Truncate all tables in a MySQL database in one command?

To truncate a table, one must drop the foreign key constraints mapped to the columns in this table from other tables (in fact on all tables in the specific DB/Schema).
So, all foreign key constraints must be dropped initially followed by table truncation.
Optionally, use the optimize table (in mysql, innodb engine esp) to reclaim the used data space/size to OS after data truncation.

Once data truncation is carried out, create the same foreign key constraints again on the same table. See below a script that would generate the script to carry out the above operations.

SELECT CONCAT('ALTER TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,' DROP FOREIGN KEY ',CONSTRAINT_NAME,';') FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
WHERE CONSTRAINT_TYPE='FOREIGN KEY' AND TABLE_SCHEMA='<TABLE SCHEMA>'
UNION
SELECT CONCAT('TRUNCATE TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,';') FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA='<TABLE SCHEMA>' AND TABLE_TYPE='BASE TABLE'
UNION
SELECT CONCAT('OPTIMIZE TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,';') FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA='<TABLE SCHEMA>' AND TABLE_TYPE='BASE TABLE'
UNION
SELECT CONCAT('ALTER TABLE ',TABLE_SCHEMA,'.',TABLE_NAME,' ADD CONSTRAINT ',CONSTRAINT_NAME,' FOREIGN KEY(',COLUMN_NAME,')',' REFERENCES ',REFERENCED_TABLE_NAME,'(',REFERENCED_COLUMN_NAME,');') FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE CONSTRAINT_NAME LIKE 'FK%' AND TABLE_SCHEMA='<TABLE SCHEMA>'
INTO OUTFILE "C:/DB Truncate.sql" LINES TERMINATED BY '\n';

Now, run the Db Truncate.sql script generated

Benefits. 1) Reclaim disk space 2) Not needed to drop and recreate the DB/Schema with the same structure

Drawbacks. 1) FK constraints should be names in the table with the name containing 'FK' in the constraint name.

adding a datatable in a dataset

I assume that you haven't set the TableName property of the DataTable, for example via constructor:

var tbl = new DataTable("dtImage");

If you don't provide a name, it will be automatically created with "Table1", the next table will get "Table2" and so on.

Then the solution would be to provide the TableName and then check with Contains(nameOfTable).

To clarify it: You'll get an ArgumentException if that DataTable already belongs to the DataSet (the same reference). You'll get a DuplicateNameException if there's already a DataTable in the DataSet with the same name(not case-sensitive).

http://msdn.microsoft.com/en-us/library/as4zy2kc.aspx

How do you configure an OpenFileDialog to select folders?

Better to use the FolderBrowserDialog for that.

using (FolderBrowserDialog dlg = new FolderBrowserDialog())
{
    dlg.Description = "Select a folder";
    if (dlg.ShowDialog() == DialogResult.OK)
    {
        MessageBox.Show("You selected: " + dlg.SelectedPath);
    }
}

async/await - when to return a Task vs void?

I got clear idea from this statements.

Async void methods have different error-handling semantics. When an exception is thrown out of an async Task or async Task method, that exception is captured and placed on the Task object. With async void methods, there is no Task object, so any exceptions thrown out of an async void method will be raised directly on the SynchronizationContext(SynchronizationContext represents a location "where" code might be executed. ) that was active when the async void method started

Exceptions from an Async Void Method Can’t Be Caught with Catch

private async void ThrowExceptionAsync()
{
  throw new InvalidOperationException();
}
public void AsyncVoidExceptions_CannotBeCaughtByCatch()
{
  try
  {
    ThrowExceptionAsync();
  }
  catch (Exception)
  {
    // The exception is never caught here!
    throw;
  }
}

These exceptions can be observed using AppDomain.UnhandledException or a similar catch-all event for GUI/ASP.NET applications, but using those events for regular exception handling is a recipe for unmaintainability(it crashes the application).

Async void methods have different composing semantics. Async methods returning Task or Task can be easily composed using await, Task.WhenAny, Task.WhenAll and so on. Async methods returning void don’t provide an easy way to notify the calling code that they’ve completed. It’s easy to start several async void methods, but it’s not easy to determine when they’ve finished. Async void methods will notify their SynchronizationContext when they start and finish, but a custom SynchronizationContext is a complex solution for regular application code.
Async Void method useful when using synchronous event handler because they raise their exceptions directly on the SynchronizationContext, which is similar to how synchronous event handlers behave

For more details check this link https://msdn.microsoft.com/en-us/magazine/jj991977.aspx

Passing references to pointers in C++

&s produces temporary pointer to string and you can't make reference to temporary object.

Security of REST authentication schemes

REST means working with the standards of the web, and the standard for "secure" transfer on the web is SSL. Anything else is going to be kind of funky and require extra deployment effort for clients, which will have to have encryption libraries available.

Once you commit to SSL, there's really nothing fancy required for authentication in principle. You can again go with web standards and use HTTP Basic auth (username and secret token sent along with each request) as it's much simpler than an elaborate signing protocol, and still effective in the context of a secure connection. You just need to be sure the password never goes over plain text; so if the password is ever received over a plain text connection, you might even disable the password and mail the developer. You should also ensure the credentials aren't logged anywhere upon receipt, just as you wouldn't log a regular password.

HTTP Digest is a safer approach as it prevents the secret token being passed along; instead, it's a hash the server can verify on the other end. Though it may be overkill for less sensitive applications if you've taken the precautions mentioned above. After all, the user's password is already transmitted in plain-text when they log in (unless you're doing some fancy JavaScript encryption in the browser), and likewise their cookies on each request.

Note that with APIs, it's better for the client to be passing tokens - randomly generated strings - instead of the password the developer logs into the website with. So the developer should be able to log into your site and generate new tokens that can be used for API verification.

The main reason to use a token is that it can be replaced if it's compromised, whereas if the password is compromised, the owner could log into the developer's account and do anything they want with it. A further advantage of tokens is you can issue multiple tokens to the same developers. Perhaps because they have multiple apps or because they want tokens with different access levels.

(Updated to cover implications of making the connection SSL-only.)

What is the point of "Initial Catalog" in a SQL Server connection string?

This is the initial database of the data source when you connect.

Edited for clarity:

If you have multiple databases in your SQL Server instance and you don't want to use the default database, you need some way to specify which one you are going to use.

Can we execute a java program without a main() method?

Now - no

Prior to Java 7:

Yes, sequence is as follows:

jvm loads class
executes static blocks
looks for main method and invokes it

So, if there's code in a static block, it will be executed. But there's no point in doing that.

How to test that:

public final class Test {
    static {
        System.out.println("FOO");
    }
}

Then if you try to run the class (either form command line with java Test or with an IDE), the result is:

FOO
java.lang.NoSuchMethodError: main

How to join two JavaScript Objects, without using JQUERY

This simple function recursively merges JSON objects, please notice that this function merges all JSON into first param (target), if you need new object modify this code.

var mergeJSON = function (target, add) {
    function isObject(obj) {
        if (typeof obj == "object") {
            for (var key in obj) {
                if (obj.hasOwnProperty(key)) {
                    return true; // search for first object prop
                }
            }
        }
        return false;
    }
    for (var key in add) {
        if (add.hasOwnProperty(key)) {
            if (target[key] && isObject(target[key]) && isObject(add[key])) {
                this.mergeJSON(target[key], add[key]);
            } else {
                target[key] = add[key];
            }
        }
    }
    return target;
};

BTW instead of isObject() function may be used condition like this:

JSON.stringify(add[key])[0] == "{"

but this is not good solution, because it's will take a lot of resources if we have large JSON objects.

How do I set the focus to the first input element in an HTML form independent from the id?

document.forms[0].elements[0].focus();

This can be refined using a loop to eg. not focus certain types of field, disabled fields and so on. Better may be to add a class="autofocus" to the field you actually do want focused, and loop over forms[i].elements[j] looking for that className.

Anyhow: it's not normally a good idea to do this on every page. When you focus an input the user loses the ability to eg. scroll the page from the keyboard. If unexpected, this can be annoying, so only auto-focus when you're pretty sure that using the form field is going to be what the user wants to do. ie. if you're Google.

Which command in VBA can count the number of characters in a string variable?

Len(word)

Although that's not what your question title asks =)

Detect when an image fails to load in Javascript

Here's a function I wrote for another answer: Javascript Image Url Verify. I don't know if it's exactly what you need, but it uses the various techniques that you would use which include handlers for onload, onerror, onabort and a general timeout.

Because image loading is asynchronous, you call this function with your image and then it calls your callback sometime later with the result.

What is the C# equivalent of NaN or IsNumeric?

Actually, Double.NaN is supported in all .NET versions 2.0 and greater.

Dump all tables in CSV format using 'mysqldump'

You also can do it using Data Export tool in dbForge Studio for MySQL.

It will allow you to select some or all tables and export them into CSV format.

Excel CSV. file with more than 1,048,576 rows of data

You can try to download and install TheGun Text Editor. Which can help you to open large csv file easily.

You can check detailed article here https://developingdaily.com/article/how-to/what-is-csv-file-and-how-to-open-a-large-csv-file/82

Can I embed a custom font in an iPhone application?

If you are using xcode 4.3, you have to add the font to the Build Phase under Copy Bundle Resources, according to https://stackoverflow.com/users/1292829/arne in the thread, Custom Fonts Xcode 4.3. This worked for me, here are the steps I took for custom fonts to work in my app:

Add the font to your project. I dragged and dropped the OTF (or TTF) files to a new group I created and accepted xcode's choice of copying the files over to the project folder.
Create the UIAppFonts array with your fonts listed as items within the array. Just the names, not the extension (e.g. "GothamBold", "GothamBold-Italic").
Click on the project name way at the top of the Project Navigator on the left side of the screen.
Click on the Build Phases tab that appears in the main area of xcode.
Expand the "Copy Bundle Resources" section and click on "+" to add the font.
Select the font file from the file navigator that pops open when you click on the "+".
Do this for every font you have to add to the project.

SQL Statement with multiple SETs and WHEREs

No, you need to handle every statement separately..

UPDATE table1
 Statement1;
 UPDATE table 1
 Statement2;

And so on

What evaluates to True/False in R?

If you think about it, comparing numbers to logical statements doesn't make much sense. However, since 0 is often associated with "Off" or "False" and 1 with "On" or "True", R has decided to allow 1 == TRUE and 0 == FALSE to both be true. Any other numeric-to-boolean comparison should yield false, unless it's something like 3 - 2 == TRUE.

Check Postgres access for a user

You could query the table_privileges table in the information schema:

SELECT table_catalog, table_schema, table_name, privilege_type
FROM   information_schema.table_privileges 
WHERE  grantee = 'MY_USER'

Can lambda functions be templated?

Here is one solution that involves wrapping the lamba in a structure:

template <typename T>                                                   
struct LamT                                                             
{                                                                       
   static void Go()                                                     
   {                                                                    
      auto lam = []()                                                   
      {                                                                 
         T var;                                                         
         std::cout << "lam, type = " << typeid(var).name() << std::endl;
      };                                                                

      lam();                                                            
   }                                                                    
};

To use do:

LamT<int>::Go();  
LamT<char>::Go(); 
#This prints 
lam, type = i
lam, type = c

The main issue with this (besides the extra typing) you cannot embed this structure definition inside another method or you get (gcc 4.9)

error: a template declaration cannot appear at block scope

I also tried doing this:

template <typename T> using LamdaT = decltype(                          
   [](void)                                                          
   {                                                                 
       std::cout << "LambT type = " << typeid(T).name() << std::endl;  
   });

With the hope that I could use it like this:

LamdaT<int>();      
LamdaT<char>();

But I get the compiler error:

error: lambda-expression in unevaluated context

So this doesn't work ... but even if it did compile it would be of limited use because we would still have to put the "using LamdaT" at file scope (because it is a template) which sort of defeats the purpose of lambdas.

How to load image to WPF in runtime?

Make sure that your sas.png is marked as Build Action: Content and Copy To Output Directory: Copy Always in its Visual Studio Properties...

I think the C# source code goes like this...

Image image = new Image();
image.Source = (new ImageSourceConverter()).ConvertFromString("pack://application:,,,/Bilder/sas.png") as ImageSource;

and XAML should be

<Image Height="200" HorizontalAlignment="Left" Margin="12,12,0,0" 
       Name="image1" Stretch="Fill" VerticalAlignment="Top" 
       Source="../Bilder/sas.png"
       Width="350" />

EDIT

Dynamically I think XAML would provide best way to load Images ...

<Image Source="{Binding Converter={StaticResource MyImageSourceConverter}}"
       x:Name="MyImage"/>

where image.DataContext is string path.

MyImage.DataContext = "pack://application:,,,/Bilder/sas.png";

public class MyImageSourceConverter : IValueConverter
{
    public object Convert(object value_, Type targetType_, 
    object parameter_, System.Globalization.CultureInfo culture_)
    {
        return (new ImageSourceConverter()).ConvertFromString (value.ToString());
    }

    public object ConvertBack(object value, Type targetType, 
    object parameter, CultureInfo culture)
    {
          throw new NotImplementedException();
    }
}

Now as you set a different data context, Image would be automatically loaded at runtime.

Find row where values for column is maximal in a pandas DataFrame

Both above answers would only return one index if there are multiple rows that take the maximum value. If you want all the rows, there does not seem to have a function. But it is not hard to do. Below is an example for Series; the same can be done for DataFrame:

In [1]: from pandas import Series, DataFrame

In [2]: s=Series([2,4,4,3],index=['a','b','c','d'])

In [3]: s.idxmax()
Out[3]: 'b'

In [4]: s[s==s.max()]
Out[4]: 
b    4
c    4
dtype: int64

How to show alert message in mvc 4 controller?

<a href="@Url.Action("DeleteBlog")" class="btn btn-sm btn-danger" onclick="return confirm ('Are you sure want to delete blog?');">

Show Youtube video source into HTML5 video tag?

This answer does not work anymore, but I'm looking for a solution.

As of . 2015 / 02 / 24 . there is a website (youtubeinmp4) that allows you to download youtube videos in .mp4 format, you can exploit this (with some JavaScript) to get away with embedding youtube videos in <video> tags. Here is a demo of this in action.

##Pros

Fairly easy to implement.
Quite fast server response actually (it doesn't take that much to retrieve the videos).
Abstraction (the accepted solution, even if it worked properly, would only be applicable if you knew beforehand which videos you were going to play, this works for any user inputted url).

##Cons

It obviously depends on the youtubeinmp4.com servers and their way of providing a downloading link (which can be passed as a <video> source), so this answer may not be valid in the future.
You can't choose the video quality.

###JavaScript (after load)

videos = document.querySelectorAll("video");
for (var i = 0, l = videos.length; i < l; i++) {
    var video = videos[i];
    var src = video.src || (function () {
        var sources = video.querySelectorAll("source");
        for (var j = 0, sl = sources.length; j < sl; j++) {
            var source = sources[j];
            var type = source.type;
            var isMp4 = type.indexOf("mp4") != -1;
            if (isMp4) return source.src;
        }
        return null;
    })();
    if (src) {
        var isYoutube = src && src.match(/(?:youtu|youtube)(?:\.com|\.be)\/([\w\W]+)/i);
        if (isYoutube) {
            var id = isYoutube[1].match(/watch\?v=|[\w\W]+/gi);
            id = (id.length > 1) ? id.splice(1) : id;
            id = id.toString();
            var mp4url = "http://www.youtubeinmp4.com/redirect.php?video=";
            video.src = mp4url + id;
        }
    }
}

###Usage (Full)

_x000D_

<video controls="true">
        <source src="www.youtube.com/watch?v=3bGNuRtlqAQ" type="video/mp4" />
    </video>

_x000D_

Standard video format.

###Usage (Mini)

_x000D_

<video src="youtu.be/MLeIBFYY6UY" controls="true"></video>

_x000D_

A little less common but quite smaller, using the shortened url youtu.be as the src attribute directly in the <video> tag.

How to implement reCaptcha for ASP.NET MVC?

There are a few great examples:

MVC reCaptcha - making reCaptcha more MVC'ish.
ReCaptcha Webhelper in ASP.NET MVC 3
ReCaptcha Control for ASP.NET MVC from Google Code.

This has also been covered before in this Stack Overflow question.

NuGet Google reCAPTCHA V2 for MVC 4 and 5

How to call javascript from a href?

another way is :

<a href="javascript:void(0);" onclick="alert('testing')">

Getting URL parameter in java and extract a specific text from that URL

I have something like this:

import org.apache.http.NameValuePair;
import org.apache.http.client.utils.URIBuilder;

private String getParamValue(String link, String paramName) throws URISyntaxException {
        List<NameValuePair> queryParams = new URIBuilder(link).getQueryParams();
        return queryParams.stream()
                .filter(param -> param.getName().equalsIgnoreCase(paramName))
                .map(NameValuePair::getValue)
                .findFirst()
                .orElse("");
    }

Running Selenium Webdriver with a proxy in Python

How about something like this

PROXY = "149.215.113.110:70"

webdriver.DesiredCapabilities.FIREFOX['proxy'] = {
    "httpProxy":PROXY,
    "ftpProxy":PROXY,
    "sslProxy":PROXY,
    "noProxy":None,
    "proxyType":"MANUAL",
    "class":"org.openqa.selenium.Proxy",
    "autodetect":False
}

# you have to use remote, otherwise you'll have to code it yourself in python to 
driver = webdriver.Remote("http://localhost:4444/wd/hub", webdriver.DesiredCapabilities.FIREFOX)

You can read more about it here.

Installation error: INSTALL_FAILED_OLDER_SDK

I found that making the recommended change in the manifest didn't solve my problem.

The fix was found in the GradleScripts folder, in the build.gradle file for the Module:app.

Inside this file (build.gradle) the following line was modified. minSdkVersion 22 I changed this '22' value to '19' for my particular phone and the build completed without error.

Determine function name from within that function (without using traceback)

import inspect

def whoami():
    return inspect.stack()[1][3]

def whosdaddy():
    return inspect.stack()[2][3]

def foo():
    print "hello, I'm %s, daddy is %s" % (whoami(), whosdaddy())
    bar()

def bar():
    print "hello, I'm %s, daddy is %s" % (whoami(), whosdaddy())

foo()
bar()

In IDE the code outputs

hello, I'm foo, daddy is

hello, I'm bar, daddy is foo

hello, I'm bar, daddy is

How to execute a file within the python interpreter?

Surprised I haven't seen this yet. You can execute a file and then leave the interpreter open after execution terminates using the -i option:

| foo.py |
----------
testvar = 10

def bar(bing):
  return bing*3

--------



$ python -i foo.py
>>> testvar 
10
>>> bar(6)
18

Install GD library and freetype on Linux

For CentOS: When installing php-gd you need to specify the version. I fixed it by running: sudo yum install php55-gd

Best way to resolve file path too long exception

The solution that worked for me was to edit the registry key to enable long path behaviour, setting the value to 1. This is a new opt-in feature for Windows 10

HKLM\SYSTEM\CurrentControlSet\Control\FileSystem LongPathsEnabled (Type: REG_DWORD)

I got this solution from a named section of the article that @james-hill posted.

https://docs.microsoft.com/windows/desktop/FileIO/naming-a-file#maximum-path-length-limitation

How can I generate Javadoc comments in Eclipse?

JAutoDoc:

an Eclipse Plugin for automatically adding Javadoc and file headers to your source code. It optionally generates initial comments from element name by using Velocity templates for Javadoc and file headers...

A simple jQuery form validation script

You can simply use the jQuery Validate plugin as follows.

jQuery:

$(document).ready(function () {

    $('#myform').validate({ // initialize the plugin
        rules: {
            field1: {
                required: true,
                email: true
            },
            field2: {
                required: true,
                minlength: 5
            }
        }
    });

});

HTML:

<form id="myform">
    <input type="text" name="field1" />
    <input type="text" name="field2" />
    <input type="submit" />
</form>

DEMO: http://jsfiddle.net/xs5vrrso/

Options: http://jqueryvalidation.org/validate

Methods: http://jqueryvalidation.org/category/plugin/

Standard Rules: http://jqueryvalidation.org/category/methods/

Optional Rules available with the additional-methods.js file:

maxWords
minWords
rangeWords
letterswithbasicpunc
alphanumeric
lettersonly
nowhitespace
ziprange
zipcodeUS
integer
vinUS
dateITA
dateNL
time
time12h
phoneUS
phoneUK
mobileUK
phonesUK
postcodeUK
strippedminlength
email2 (optional TLD)
url2 (optional TLD)
creditcardtypes
ipv4
ipv6
pattern
require_from_group
skip_or_fill_minimum
accept
extension

How to specify the private SSH-key to use when executing shell command on Git?

Something like this should work (suggested by orip):

ssh-agent bash -c 'ssh-add /somewhere/yourkey; git clone [email protected]:user/project.git'

if you prefer subshells, you could try the following (though it is more fragile):

ssh-agent $(ssh-add /somewhere/yourkey; git clone [email protected]:user/project.git)

Git will invoke SSH which will find its agent by environment variable; this will, in turn, have the key loaded.

Alternatively, setting HOME may also do the trick, provided you are willing to setup a directory that contains only a .ssh directory as HOME; this may either contain an identity.pub, or a config file setting IdentityFile.

How to remove td border with html?

Surround it with a div and give it a border and remove the border from the table

<div style="border: 1px solid black">
    <table border="0">
        <tr>
            <td>one</td>
            <td>two</td>
        </tr>
        <tr>
            <td>one</td>
            <td>two</td>
        </tr>
    </table>
</div>

You can check the working fiddle here

As per your updated question .... where you want to add or remove borders. You should remove borders from the html table first and then do the following

<td style="border-top: 1px solid black">

Assuming like you only want the top border. Similarly you have to do for others. Better way create four css class...

.topBorderOnly {
    border-top: 1px solid black;
}

.bottomBorderOnly {
    border-bottom: 1px solid black;
}

Then add the css to your code depending on the requirements.

<td class="topBorderOnly bottomBorderOnly">

This will add both top and bottom border, similarly do for the rest.

Rounding a double value to x number of decimal places in swift

This is a fully worked code

Swift 3.0/4.0/5.0 , Xcode 9.0 GM/9.2 and above

let doubleValue : Double = 123.32565254455
self.lblValue.text = String(format:"%.f", doubleValue)
print(self.lblValue.text)

output - 123

let doubleValue : Double = 123.32565254455
self.lblValue_1.text = String(format:"%.1f", doubleValue)
print(self.lblValue_1.text)

output - 123.3

let doubleValue : Double = 123.32565254455
self.lblValue_2.text = String(format:"%.2f", doubleValue)
print(self.lblValue_2.text)

output - 123.33

let doubleValue : Double = 123.32565254455
self.lblValue_3.text = String(format:"%.3f", doubleValue)
print(self.lblValue_3.text)

output - 123.326

Twitter Bootstrap 3.0 how do I "badge badge-important" now

Another possible way, in order to make the colors a bit more intense, is this one:

<span class="badge progress-bar-info">10</span>
<span class="badge progress-bar-success">20</span>
<span class="badge progress-bar-warning">30</span>
<span class="badge progress-bar-danger">40</span>

See Bootply

How to retrieve the current value of an oracle sequence without increment it?

My original reply was factually incorrect and I'm glad it was removed. The code below will work under the following conditions a) you know that nobody else modified the sequence b) the sequence was modified by your session. In my case, I encountered a similar issue where I was calling a procedure which modified a value and I'm confident the assumption is true.

SELECT mysequence.CURRVAL INTO v_myvariable FROM DUAL;

Sadly, if you didn't modify the sequence in your session, I believe others are correct in stating that the NEXTVAL is the only way to go.

Html.Raw() in ASP.NET MVC Razor view

The accepted answer is correct, but I prefer:

@{int count = 0;} 
@foreach (var item in Model.Resources) 
{ 
    @Html.Raw(count <= 3 ? "<div class=\"resource-row\">" : "")  
    // some code 
    @Html.Raw(count <= 3 ? "</div>" : "")  
    @(count++)
}

I hope this inspires someone, even though I'm late to the party.

How do I enumerate through a JObject?

For people like me, linq addicts, and based on svick's answer, here a linq approach:

using System.Linq;
//...
//make it linq iterable. 
var obj_linq = Response.Cast<KeyValuePair<string, JToken>>();

Now you can make linq expressions like:

JToken x = obj_linq
          .Where( d => d.Key == "my_key")
          .Select(v => v)
          .FirstOrDefault()
          .Value;
string y = ((JValue)x).Value;

Or just:

var y = obj_linq
       .Where(d => d.Key == "my_key")
       .Select(v => ((JValue)v.Value).Value)
       .FirstOrDefault();

Or this one to iterate over all data:

obj_linq.ToList().ForEach( x => { do stuff } );

How to Create a script via batch file that will uninstall a program if it was installed on windows 7 64-bit or 32-bit

wmic can call an uninstaller. I haven't tried this, but I think it might work.

wmic /node:computername /user:adminuser /password:password product where name="name of application" call uninstall

If you don't know exactly what the program calls itself, do

wmic product get name | sort

and look for it. You can also uninstall using SQL-ish wildcards.

wmic /node:computername /user:adminuser /password:password product where "name like '%j2se%'" call uninstall

... for example would perform a case-insensitive search for *j2se* and uninstall "J2SE Runtime Environment 5.0 Update 12". (Note that in the example above, %j2se% is not an environment variable, but simply the word "j2se" with a SQL-ish wildcard on each end. If your search string could conflict with an environment or script variable, use double percents to specify literal percent signs, like %%j2se%%.)

If wmic prompts for y/n confirmation before completing the uninstall, try this:

echo y | wmic /node:computername /user:adminuser /password:password product where name="whatever" call uninstall

... to pass a y to it before it even asks.

I haven't tested this, but it's worth a shot anyway. If it works on one computer, then you can just loop through a text file containing all the computer names within your organization using a for loop, or put it in a domain policy logon script.

How can I format the output of a bash command in neat columns

While awk's printf can be used, you may want to look into pr or (on BSDish systems) rs for formatting.

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

See this script for registering. It is simple and very easy to understand.

<?php
    define('DB_HOST', 'Your Host[Could be localhost or also a website]');
    define('DB_NAME', 'database name');
    define('DB_USERNAME', 'Username[In many cases root, but some sites offer a MySQL page where the username might be different]');
    define('DB_PASSWORD', 'whatever you keep[if username is root then 99% of the password is blank]');

    $link = mysql_connect(DB_HOST, DB_USERNAME, DB_PASSWORD);

    if (!$link) {
        die('Could not connect line 9');
    }

    $DB_SELECT = mysql_select_db(DB_NAME, $link);

    if (!$DB_SELECT) {
        die('Could not connect line 15');
    }

    $valueone = $_POST['name'];
    $valuetwo = $_POST['last_name'];
    $valuethree = $_POST['email'];
    $valuefour = $_POST['password'];
    $valuefive = $_POST['age'];

    $sqlone = "INSERT INTO user (name, last_name, email, password, age) VALUES ('$valueone','$valuetwo','$valuethree','$valuefour','$valuefive')";

    if (!mysql_query($sqlone)) {
        die('Could not connect name line 33');
    }

    mysql_close();
?>

Make sure you make all the database stuff using phpMyAdmin. It's a very easy tool to work with. You can find it here: phpMyAdmin

How can I combine flexbox and vertical scroll in a full-height app?

Thanks to https://stackoverflow.com/users/1652962/cimmanon that gave me the answer.

The solution is setting a height to the vertical scrollable element. For example:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    height: 0px;
}

The element will have height because flexbox recalculates it unless you want a min-height so you can use height: 100px; that it is exactly the same as: min-height: 100px;

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    height: 100px; /* == min-height: 100px*/
}

So the best solution if you want a min-height in the vertical scroll:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    min-height: 100px;
}

If you just want full vertical scroll in case there is no enough space to see the article:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    min-height: 0px;
}

The final code: http://jsfiddle.net/ch7n6/867/

String replace a Backslash

This will replace backslashes with forward slashes in the string:

source = source.replace('\\','/');

How can I check if a Perl array contains a particular value?

@files is an existing array

my @new_values =  grep(/^2[\d].[\d][A-za-z]?/,@files);

print join("\n", @new_values);

print "\n";

/^2[\d].[\d][A-za-z]?/ = vaues starting from 2 here you can put any regular expression

Go doing a GET request and building the Querystring

As a commenter mentioned you can get Values from net/url which has an Encode method. You could do something like this (req.URL.Query() returns the existing url.Values)

package main

import (
    "fmt"
    "log"
    "net/http"
    "os"
)

func main() {
    req, err := http.NewRequest("GET", "http://api.themoviedb.org/3/tv/popular", nil)
    if err != nil {
        log.Print(err)
        os.Exit(1)
    }

    q := req.URL.Query()
    q.Add("api_key", "key_from_environment_or_flag")
    q.Add("another_thing", "foo & bar")
    req.URL.RawQuery = q.Encode()

    fmt.Println(req.URL.String())
    // Output:
    // http://api.themoviedb.org/3/tv/popular?another_thing=foo+%26+bar&api_key=key_from_environment_or_flag
}

http://play.golang.org/p/L5XCrw9VIG

Difference between e.target and e.currentTarget

I like visual answers.

When you click #btn, two event handlers get called and they output what you see in the picture.

Demo here: https://jsfiddle.net/ujhe1key/

Switch case on type c#

The following code works more or less as one would expect a type-switch that only looks at the actual type (e.g. what is returned by GetType()).

public static void TestTypeSwitch()
{
    var ts = new TypeSwitch()
        .Case((int x) => Console.WriteLine("int"))
        .Case((bool x) => Console.WriteLine("bool"))
        .Case((string x) => Console.WriteLine("string"));

    ts.Switch(42);     
    ts.Switch(false);  
    ts.Switch("hello"); 
}

Here is the machinery required to make it work.

public class TypeSwitch
{
    Dictionary<Type, Action<object>> matches = new Dictionary<Type, Action<object>>();
    public TypeSwitch Case<T>(Action<T> action) { matches.Add(typeof(T), (x) => action((T)x)); return this; } 
    public void Switch(object x) { matches[x.GetType()](x); }
}

Post multipart request with Android SDK

More easy, light (32k), and many more performance:

Android Asynchronous Http Client library: http://loopj.com/android-async-http/

Implementation:

How to send a “multipart/form-data” POST in Android with Volley

How to log in to phpMyAdmin with WAMP, what is the username and password?

Try username = root and password is blank.

Create HTML table using Javascript

In the html file there are three input boxes with userid,username,department respectively.

These inputboxes are used to get the input from the user.

The user can add any number of inputs to the page.

When clicking the button the script will enable the debugger mode.

In javascript, to enable the debugger mode, we have to add the following tag in the javascript.

/************************************************************************\

    Tools->Internet Options-->Advanced-->uncheck
    Disable script debugging(Internet Explorer)
    Disable script debugging(Other)

    <html xmlns="http://www.w3.org/1999/xhtml" >

    <head runat="server">

    <title>Dynamic Table</title>

    <script language="javascript" type="text/javascript">

    // <!CDATA[

    function CmdAdd_onclick() {

    var newTable,startTag,endTag;



    //Creating a new table

    startTag="<TABLE id='mainTable'><TBODY><TR><TD style=\"WIDTH: 120px\">User ID</TD>
    <TD style=\"WIDTH: 120px\">User Name</TD><TD style=\"WIDTH: 120px\">Department</TD></TR>"

    endTag="</TBODY></TABLE>"

    newTable=startTag;

    var trContents;

    //Get the row contents

    trContents=document.body.getElementsByTagName('TR');

    if(trContents.length>1)

    {

    for(i=1;i<trContents.length;i++)

    {

    if(trContents(i).innerHTML)

    {

    // Add previous rows

    newTable+="<TR>";

    newTable+=trContents(i).innerHTML;

    newTable+="</TR>";

    } 

    }

    }

    //Add the Latest row

    newTable+="<TR><TD style=\"WIDTH: 120px\" >" +
        document.getElementById('userid').value +"</TD>";

    newTable+="<TD style=\"WIDTH: 120px\" >" +
        document.getElementById('username').value +"</TD>";

    newTable+="<TD style=\"WIDTH: 120px\" >" +
        document.getElementById('department').value +"</TD><TR>";

    newTable+=endTag;

    //Update the Previous Table With New Table.

    document.getElementById('tableDiv').innerHTML=newTable;

    }

    // ]]>

    </script>

    </head>

    <body>

    <form id="form1" runat="server">

    <div>

    <br />

    <label>UserID</label> 

    <input id="userid" type="text" /><br />

    <label>UserName</label> 

    <input id="username" type="text" /><br />

    <label>Department</label> 

    <input id="department" type="text" />

    <center>

    <input id="CmdAdd" type="button" value="Add" onclick="return CmdAdd_onclick()" />
    </center>



    </div>

    <div id="tableDiv" style="text-align:center" >

    <table id="mainTable">

    <tr style="width:120px " >

    <td >User ID</td>

    <td>User Name</td>

    <td>Department</td>

    </tr>

    </table>

    </div>

    </form>

    </body>

    </html>

Scroll RecyclerView to show selected item on top

I don't know why I didn't find the best answer but its really simple.

recyclerView.smoothScrollToPosition(position);

No errors

Creates Animations

Run a vbscript from another vbscript

In case you don't want to get mad with spaces in arguments and want to use variables try this:

objshell.run "cscript ""99 Writelog.vbs"" /r:" &  r & " /f:""" & wscript.scriptname & """ /c:""" & c & ""

where

r=123
c="Whatever comment you like"

Is it possible to start activity through adb shell?

You can also find the name of the current on screen activity using

adb shell dumpsys window windows | grep 'mCurrentFocus'

Can a PDF file's print dialog be opened with Javascript?

I use named action instead of javascript because javascript often is disabled, and if it isn't it gives a warning.

My web application creates a postscript file that then is converted with ghostscript to a pdf. I want it to print automatically because the user has already clicked on print inside my application. With the information about named actions from @DSimon above, I researched how to solve this. It all boils down to insert the string /Type /Action /S /Named /N /Print at the right place in the pdf.

I was thinking of writing a small utility, but it has to parse the pdf to find the root node, insert /OpenAction with a reference an object with the action, and recalculate the byte-offsets in xref.

But then I found out about pdfmark which is an extension to postscript to express, in postscript syntax, idioms that are converted to pdf by Adobes distiller or by ghostscript.

Since I'm already using ghostscript, all I have to do is append the following to the end of my postscript file:

%AUTOPRINT
[ /_objdef {PrintAction} /type /dict /OBJ pdfmark
[ {PrintAction} << /Type /Action /S /Named /N /Print >> /PUT pdfmark
[ {Catalog} << /OpenAction {PrintAction} >> /PUT pdfmark

and ghostscript will create the action, link it, and calculate the xref offsets. (In postscript % is a comment and PrintAction is my name for the object)

By looking at the PDF I see that it has created this:

1 0 obj
<</Type /Catalog /Pages 3 0 R
/OpenAction  9 0 R
/Metadata 10 0 R
>>
endobj

9 0 obj
<</S/Named
/Type/Action
/N/Print>>endobj

1 0 is object 1, revision 0, and 9 0 is object 9, revision 0. In the pdf-trailer is says that it is object 1 that is the root node. As you can see there is a reference from object 1, /OpenAction to run object 9 revision 0.

With ghostscript it's possible to convert a pdf to postscript (pdf2ps), append the text above, and convert it back to pdf with ps2pdf. It should be noted that meta-information about the pdf is lost in this conversion. I haven't searched more into this.

What is the difference between call and apply?

Another example with Call, Apply and Bind. The difference between Call and Apply is evident, but Bind works like this:

Bind returns an instance of a function that can be executed
First Parameter is 'this'
Second parameter is a Comma separated list of arguments (like Call)

}

function Person(name) {
    this.name = name; 
}
Person.prototype.getName = function(a,b) { 
     return this.name + " " + a + " " + b; 
}

var reader = new Person('John Smith');

reader.getName = function() {
   // Apply and Call executes the function and returns value

   // Also notice the different ways of extracting 'getName' prototype
   var baseName = Object.getPrototypeOf(this).getName.apply(this,["is a", "boy"]);
   console.log("Apply: " + baseName);

   var baseName = Object.getPrototypeOf(reader).getName.call(this, "is a", "boy"); 
   console.log("Call: " + baseName);

   // Bind returns function which can be invoked
   var baseName = Person.prototype.getName.bind(this, "is a", "boy"); 
   console.log("Bind: " + baseName());
}

reader.getName();
/* Output
Apply: John Smith is a boy
Call: John Smith is a boy
Bind: John Smith is a boy
*/

What is the Difference Between Mercurial and Git?

There is a great and exhaustive comparison tables and charts on git, Mercurial and Bazaar over at InfoQ's guide about DVCS.

Wildcard string comparison in Javascript

Instead Animals == "bird*" Animals = "bird*" should work.

HTML combo box with option to type an entry

in HTML, you do this backwards: You define a text input:

<input type="text" list="browsers" />

and attach a datalist to it. (note the list attribute of the input).

<datalist id="browsers">
  <option value="Internet Explorer">
  <option value="Firefox">
  <option value="Chrome">
  <option value="Opera">
  <option value="Safari">
</datalist>

css transition opacity fade background

It's not fading to "black transparent" or "white transparent". It's just showing whatever color is "behind" the image, which is not the image's background color - that color is completely hidden by the image.

If you want to fade to black(ish), you'll need a black container around the image. Something like:

.ctr {
    margin: 0; 
    padding: 0;
    background-color: black;
    display: inline-block;
}

and

<div class="ctr"><img ... /></div>

Accessing UI (Main) Thread safely in WPF

The best way to go about it would be to get a SynchronizationContext from the UI thread and use it. This class abstracts marshalling calls to other threads, and makes testing easier (in contrast to using WPF's Dispatcher directly). For example:

class MyViewModel
{
    private readonly SynchronizationContext _syncContext;

    public MyViewModel()
    {
        // we assume this ctor is called from the UI thread!
        _syncContext = SynchronizationContext.Current;
    }

    // ...

    private void watcher_Changed(object sender, FileSystemEventArgs e)
    {
         _syncContext.Post(o => DGAddRow(crp.Protocol, ft), null);
    }
}

Java and HTTPS url connection without downloading certificate

If you are using any Payment Gateway to hit any url just to send a message, then i used a webview by following it : How can load https url without use of ssl in android webview

and make a webview in your activity with visibility gone. What you need to do : just load that webview.. like this:

 webViewForSms.setWebViewClient(new SSLTolerentWebViewClient());
                webViewForSms.loadUrl(" https://bulksms.com/" +
                        "?username=test&password=test@123&messageType=text&mobile="+
                        mobileEditText.getText().toString()+"&senderId=ATZEHC&message=Your%20OTP%20for%20A2Z%20registration%20is%20124");

Easy.

You will get this: SSLTolerentWebViewClient from this link: How can load https url without use of ssl in android webview

What's the difference between setWebViewClient vs. setWebChromeClient?

From the source code:

// Instance of WebViewClient that is the client callback.
private volatile WebViewClient mWebViewClient;
// Instance of WebChromeClient for handling all chrome functions.
private volatile WebChromeClient mWebChromeClient;

// SOME OTHER SUTFFF.......

/**
 * Set the WebViewClient.
 * @param client An implementation of WebViewClient.
 */
public void setWebViewClient(WebViewClient client) {
    mWebViewClient = client;
}

/**
 * Set the WebChromeClient.
 * @param client An implementation of WebChromeClient.
 */
public void setWebChromeClient(WebChromeClient client) {
    mWebChromeClient = client;
}

Using WebChromeClient allows you to handle Javascript dialogs, favicons, titles, and the progress. Take a look of this example: Adding alert() support to a WebView

At first glance, there are too many differences WebViewClient & WebChromeClient. But, basically: if you are developing a WebView that won't require too many features but rendering HTML, you can just use a WebViewClient. On the other hand, if you want to (for instance) load the favicon of the page you are rendering, you should use a WebChromeClient object and override the onReceivedIcon(WebView view, Bitmap icon).

Most of the times, if you don't want to worry about those things... you can just do this:

webView= (WebView) findViewById(R.id.webview); 
webView.setWebChromeClient(new WebChromeClient()); 
webView.setWebViewClient(new WebViewClient()); 
webView.getSettings().setJavaScriptEnabled(true); 
webView.loadUrl(url);

And your WebView will (in theory) have all features implemented (as the android native browser).

Should I use the datetime or timestamp data type in MySQL?

In MySQL 5 and above, TIMESTAMP values are converted from the current time zone to UTC for storage, and converted back from UTC to the current time zone for retrieval. (This occurs only for the TIMESTAMP data type, and not for other types such as DATETIME.)

By default, the current time zone for each connection is the server's time. The time zone can be set on a per-connection basis, as described in MySQL Server Time Zone Support.

How to convert array to a string using methods other than JSON?

Another good alternative is http_build_query

$data = array('foo'=>'bar',
              'baz'=>'boom',
              'cow'=>'milk',
              'php'=>'hypertext processor');

echo http_build_query($data) . "\n";
echo http_build_query($data, '', '&amp;');

Will print

foo=bar&baz=boom&cow=milk&php=hypertext+processor
foo=bar&amp;baz=boom&amp;cow=milk&amp;php=hypertext+processor

More info here http://php.net/manual/en/function.http-build-query.php

Why doesn't height: 100% work to expand divs to the screen height?

Here's another solution for people who don't want to use html, body, .blah { height: 100% }.

_x000D_

.app {_x000D_
  position: fixed;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  overflow-y: auto;_x000D_
}_x000D_
_x000D_
.full-height {_x000D_
  height: 100%;_x000D_
}_x000D_
_x000D_
.test {_x000D_
  width: 10px;_x000D_
  background: red;_x000D_
}

_x000D_

<div class="app">_x000D_
  <div class="full-height test">_x000D_
  </div>_x000D_
  Scroll works too_x000D_
</div>

_x000D_

javascript toISOString() ignores timezone offset

Using moment.js, you can use keepOffset parameter of toISOString:

toISOString(keepOffset?: boolean): string;

moment().toISOString(true)

How to bind bootstrap popover on dynamic elements

Update

If your popover is going to have a selector that is consistent then you can make use of selector property of popover constructor.

var popOverSettings = {
    placement: 'bottom',
    container: 'body',
    html: true,
    selector: '[rel="popover"]', //Sepcify the selector here
    content: function () {
        return $('#popover-content').html();
    }
}

$('body').popover(popOverSettings);

Demo

Other ways:

(Standard Way) Bind the popover again to the new items being inserted. Save the popoversettings in an external variable.
Use Mutation Event/Mutation Observer to identify if a particular element has been inserted on to the ul or an element.

Source

var popOverSettings = { //Save the setting for later use as well
    placement: 'bottom',
    container: 'body',
    html: true,
    //content:" <div style='color:red'>This is your div content</div>"
    content: function () {
        return $('#popover-content').html();
    }

}

$('ul').on('DOMNodeInserted', function () { //listed for new items inserted onto ul
    $(event.target).popover(popOverSettings);
});

$("button[rel=popover]").popover(popOverSettings);
$('.pop-Add').click(function () {
    $('ul').append("<li class='project-name'>     <a>project name 2        <button class='pop-function' rel='popover'></button>     </a>   </li>");
});

But it is not recommended to use DOMNodeInserted Mutation Event for performance issues as well as support. This has been deprecated as well. So your best bet would be to save the setting and bind after you update with new element.

Demo

Another recommended way is to use MutationObserver instead of MutationEvent according to MDN, but again support in some browsers are unknown and performance a concern.

MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
// create an observer instance
var observer = new MutationObserver(function (mutations) {
    mutations.forEach(function (mutation) {
        $(mutation.addedNodes).popover(popOverSettings);
    });
});

// configuration of the observer:
var config = {
     attributes: true, 
     childList: true, 
     characterData: true
};

// pass in the target node, as well as the observer options
observer.observe($('ul')[0], config);

Demo

Java: Clear the console

You need to use JNI.

First of all use create a .dll using visual studio, that call system("cls"). After that use JNI to use this DDL.

I found this article that is nice:

http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=5170&lngWId=2

Git push requires username and password

Updating your Git configuration file directly (if you do not want to memorize fancy commands):

Open your .git/config file in your favorite text editor. It will be in the folder that you cloned or in the repository that you performed git init in. Go into that repository. .git is a hidden folder, and pressing Ctrl + H should show the hidden folder, (ls -a in terminal).

Below is a sample of the .git/config file. Copy and paste these lines and be sure to update those lines with your Git information.

[user]
        name = Tux
        email = [email protected]
        username = happy_feet

[remote "origin"]
        url = https://github.com/happy_feet/my_code.git
        fetch = +refs/heads/*:refs/remotes/origin/*

Change the URL part with the following format for SSH:

url = [email protected]:happy_feet/my_code.git

(The above formats do not change with various Git remote servers like GitHub or Bitbucket. It's the same if you are using Git for version control):

Note: The SSH way of connecting to a remote Git repository will require you to add your public SSH key to your Git remote server (like GitHub or Bitbucket. Search the settings page for SSH keys).

To know how to generate your SSH keys, refer to: Creating SSH keys

Python function overloading

The @overload decorator was added with type hints (PEP 484).

While this doesn't change the behaviour of Python, it does make it easier to understand what is going on, and for mypy to detect errors.

See: Type hints and PEP 484

How do I correctly clone a JavaScript object?

Per MDN:

If you want shallow copy, use Object.assign({}, a)
For "deep" copy, use JSON.parse(JSON.stringify(a))

There is no need for external libraries but you need to check browser compatibility first.

Xcode iOS 8 Keyboard types not supported

This error had come when your keyboard input type is Number Pad.I got same error than I change my Textfield keyboard input type to Default fix my issue.

How to add additional fields to form before submit?

Try this:

$('#form').submit(function(eventObj) {
    $(this).append('<input type="hidden" name="field_name" value="value" /> ');
    return true;
});

Set up a scheduled job?

Yes, the method above is so great. And I tried some of them. At last, I found a method like this:

    from threading import Timer

    def sync():

        do something...

        sync_timer = Timer(self.interval, sync, ())
        sync_timer.start()

Just like Recursive.

Ok, I hope this method can meet your requirement. :)

Concat all strings inside a List<string> using LINQ

Put String.Join into an extension method. Here is the version I use, which is less verbose than Jordaos version.

returns empty string "" when list is empty. Aggregate would throw exception instead.
probably better performance than Aggregate
is easier to read when combined with other LINQ methods than a pure String.Join()

Usage

var myStrings = new List<string>() { "a", "b", "c" };
var joinedStrings = myStrings.Join(",");  // "a,b,c"

Extensionmethods class

public static class ExtensionMethods
{
    public static string Join(this IEnumerable<string> texts, string separator)
    {
        return String.Join(separator, texts);
    }
}

Encrypt and Decrypt in Java

You may want to use the jasypt library (Java Simplified Encryption), which is quite easy to use. ( Also, it's recommended to check against the encrypted password rather than decrypting the encrypted password )

To use jasypt, if you're using maven, you can include jasypt into your pom.xml file as follows:

<dependency>
    <groupId>org.jasypt</groupId>
    <artifactId>jasypt</artifactId>
    <version>1.9.3</version>
    <scope>compile</scope>
</dependency>

And then to encrypt the password, you can use StrongPasswordEncryptor

public static String encryptPassword(String inputPassword) {
    StrongPasswordEncryptor encryptor = new StrongPasswordEncryptor();
    return encryptor.encryptPassword(inputPassword);
}

Note: the encrypted password is different every time you call encryptPassword but the checkPassword method can still check that the unencrypted password still matches each of the encrypted passwords.

And to check the unencrypted password against the encrypted password, you can use the checkPassword method:

public static boolean checkPassword(String inputPassword, String encryptedStoredPassword) {
    StrongPasswordEncryptor encryptor = new StrongPasswordEncryptor();
    return encryptor.checkPassword(inputPassword, encryptedStoredPassword);
}

The page below provides detailed information on the complexities involved in creating safe encrypted passwords.

http://www.jasypt.org/howtoencryptuserpasswords.html

How to stop Python closing immediately when executed in Microsoft Windows

In Python 3, add the following to the end of your code:

input('Press ENTER to exit')

This will cause the program to wait for user input, with pressing ENTER causing the program to finish.

You can double click on your script.py file in Windows conveniently this way.

Eclipse Indigo - Cannot install Android ADT Plugin

Ensure you have the option "Contact all update sites during install to find required software". This option is located in the lower left corner on the first screen after choosing Help/Add New Software. This is unchecked by default. This WILL FIX the issue if it was unchecked.

The plugin will install in 3.7 32bit and 64bit.

ExecutorService that interrupts tasks after a timeout

How about using the ExecutorService.shutDownNow() method as described in http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html? It seems to be the simplest solution.

Why doesn't Python have a sign function?

Only correct answer compliant with the Wikipedia definition

The definition on Wikipedia reads:

$sign definition$

Hence,

sign = lambda x: -1 if x < 0 else (1 if x > 0 else (0 if x == 0 else NaN))

Which for all intents and purposes may be simplified to:

sign = lambda x: -1 if x < 0 else (1 if x > 0 else 0)

This function definition executes fast and yields guaranteed correct results for 0, 0.0, -0.0, -4 and 5 (see comments to other incorrect answers).

Note that zero (0) is neither positive nor negative.

LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria

One thing that is missed in the responses....

If there are multiple results, FirstOrDefault without an order by can bring back different results based on which ever index strategy happened to be used by the server.

Personally I cannot stand seeing FirstOrDefault in code because to me it says the developer didn't care about the results. With an order by though it can be useful as a way of enforcing the latest/earliest. I've had to correct a lot of issues caused by careless developers using FirstOrDefault.

Programs & Examples On #Svn organization

Using jQuery To Get Size of Viewport

Update built-in vim on Mac OS X

How to shutdown my Jenkins safely?

Way to go from recursion to iteration

Sum of values in an array using jQuery

How do I split a string on a delimiter in Bash?

destination path already exists and is not an empty directory

Can I embed a .png image into an html page?

Sql query to insert datetime in SQL Server

How can I disable ARC for a single file in a project?

Error Code: 1406. Data too long for column - MySQL

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

How to get client's IP address using JavaScript?

Why is the minidlna database not being refreshed?

How can I get a character in a string by index?

How to check certificate name and alias in keystore files?

INSERT IF NOT EXISTS ELSE UPDATE?

How to show imageView full screen on imageView click?

How can I revert a single file to a previous version?

How can I remove the outline around hyperlinks images?

Loading custom functions in PowerShell

How to 'update' or 'overwrite' a python list

Angularjs on page load call function

pip cannot install anything

Difference between spring @Controller and @RestController annotation

SQL JOIN and different types of JOINs

Types of JOINS:

Examples:

Vue.js img src concatenate variable and text

Image encryption/decryption using AES256 symmetric block ciphers

GetFiles with multiple extensions

.NET Core vs Mono

Does java have a int.tryparse that doesn't throw an exception for bad data?

Java AES and using my own Key

What is Python used for?

Why should you learn Python Programming Language?

What is Python Programming Language used for?

How to use ng-repeat without an html element

In a unix shell, how to get yesterday's date into a variable?

Using G++ to compile multiple .cpp and .h files

Generate a heatmap in MatPlotLib using a scatter data set

ExecJS and could not find a JavaScript runtime

Copy Image from Remote Server Over HTTP

What is a regular expression which will match a valid domain name without a subdomain?

top -c command in linux to filter processes listed based on processname

How do I restore a dump file from mysqldump?

trim left characters in sql server?

Make an existing Git branch track a remote branch?

CSS override rules and specificity

How does strtok() split the string into tokens in C?

Get current URL/URI without some of $_GET variables

Yii 1

For Yii2:

How to set proper codeigniter base url?

Execute write on doc: It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.

Change bundle identifier in Xcode when submitting my first app in IOS

How to replace all occurrences of a string in Javascript?

Is null check needed before calling instanceof?

javax.servlet.ServletException cannot be resolved to a type in spring web app

POST data to a URL in PHP

How to use timer in C?

Error: the entity type requires a primary key

Spring: How to inject a value to static field?

Jquery: Find Text and replace

How to order results with findBy() in Doctrine

How to load npm modules in AWS Lambda?

Way to get number of digits in an int?

Is it possible to use JS to open an HTML select to show its option list?

Insert an item into sorted list in Python

Get Substring between two characters using javascript

MySQL show status - active or total connections?

What is the most efficient/elegant way to parse a flat table into a tree?

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

android.content.Context.getPackageName()' on a null object reference

How can I access an internal class from an external assembly?

Calling jQuery method from onClick attribute in HTML

Add a pipe separator after items in an unordered list unless that item is the last on a line

What are the First and Second Level caches in (N)Hibernate?

Make just one slide different size in Powerpoint