Convert XML to JSON (and back) using Javascript

You can also use txml. It can parse into a DOM made of simple objects and stringify. In the result, the content will be trimmed. So formating of the original with whitespaces will be lost. But this could be used very good to minify HTML.

const xml = require('txml');
const data = `
<tag>tag content</tag>
<tag2>another content</tag2>
<tag3>
  <insideTag>inside content</insideTag>
  <emptyTag />
</tag3>`;

const dom = xml(data); // the dom can be JSON.stringified

xml.stringify(dom); // this will return the dom into an xml-string

Disclaimer: I am the author of txml, the fastest xml parser in javascript.

How to make an Android Spinner with initial text "Select One"?

public AdapterView.OnItemSelectedListener instructorSpinnerListener = new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView << ? > adapterView, View view, int i, long l) {
        String selectedInstructorName = adapterView.getItemAtPosition(i).toString();
        if (selectedInstructorName.equals("[Select Instructor]")) {
            instructorSpinnerAdapter.clear();
            for (Offering offering: allOfferingsList)
                instructorSpinnerAdapter.add(offering);
        } else {
            instructorSpinnerAdapter.clear();
        }
    }

    @Override
    public void onNothingSelected(AdapterView<< ? > adapterView) {
        adapterView.setSelection(0);

        // Toast.makeText(getApplicationContext(), "Why?", Toast.LENGTH_SHORT).show();
    }
};

getElementsByClassName not working

There are several issues:

Class names (and IDs) are not allowed to start with a digit.
You have to pass a class to getElementsByClassName().
You have to iterate of the result set.

Example (untested):

<script type="text/javascript">
function hideTd(className){
    var elements = document.getElementsByClassName(className);
    for(var i = 0, length = elements.length; i < length; i++) {
       if( elements[i].textContent == ''){
          elements[i].style.display = 'none';
       } 
    }

  }
</script>
</head>
<body onload="hideTd('td');">
<table border="1">
  <tr>
    <td class="td">not empty</td>
  </tr>
  <tr>
    <td class="td"></td>
  </tr>
  <tr>
    <td class="td"></td>
  </tr>
</table>
</body>

Note that getElementsByClassName() is not available up to and including IE8.

Update:

Alternatively you can give the table an ID and use:

var elements = document.getElementById('tableID').getElementsByTagName('td');

to get all td elements.

To hide the parent row, use the parentNode property of the element:

elements[i].parentNode.style.display = "none";

How to remove listview all items

I just clean the arraylist , try values.clear();

values = new ArrayList<String>();
values.clear();

ArrayAdapter <String> adapter;
adapter = new ArrayAdapter<String>(this, R.layout.list,android.R.id.text1, values); 
lista.setAdapter(adapter);

Setting Django up to use MySQL

MySQL support is simple to add. In your DATABASES dictionary, you will have an entry like this:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql', 
        'NAME': 'DB_NAME',
        'USER': 'DB_USER',
        'PASSWORD': 'DB_PASSWORD',
        'HOST': 'localhost',   # Or an IP Address that your DB is hosted on
        'PORT': '3306',
    }
}

You also have the option of utilizing MySQL option files, as of Django 1.7. You can accomplish this by setting your DATABASES array like so:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'OPTIONS': {
            'read_default_file': '/path/to/my.cnf',
        },
    }
}

You also need to create the /path/to/my.cnf file with similar settings from above

[client]
database = DB_NAME
host = localhost
user = DB_USER
password = DB_PASSWORD
default-character-set = utf8

With this new method of connecting in Django 1.7, it is important to know the order connections are established:

1. OPTIONS.
2. NAME, USER, PASSWORD, HOST, PORT
3. MySQL option files.

In other words, if you set the name of the database in OPTIONS, this will take precedence over NAME, which would override anything in a MySQL option file.

If you are just testing your application on your local machine, you can use

python manage.py runserver

Adding the ip:port argument allows machines other than your own to access your development application. Once you are ready to deploy your application, I recommend taking a look at the chapter on Deploying Django on the djangobook

Mysql default character set is often not utf-8, therefore make sure to create your database using this sql:

CREATE DATABASE mydatabase CHARACTER SET utf8 COLLATE utf8_bin

If you are using Oracle's MySQL connector your ENGINE line should look like this:

'ENGINE': 'mysql.connector.django',

Note that you will first need to install mysql on your OS.

brew install mysql (MacOS)

Also, the mysql client package has changed for python 3 (MySQL-Client works only for python 2)

pip3 install mysqlclient

How to call an element in a numpy array?

Also, you could try to use ndarray.item(), for example, arr.item((0, 0))(rowid+colid to index) or arr.item(0)(flatten index), its doc https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.item.html

How can I exclude directories from grep -R?

A simpler way would be to filter your results using "grep -v".

grep -i needle -R * | grep -v node_modules

C read file line by line

A complete, fgets() solution:

#include <stdio.h>
#include <string.h>

#define MAX_LEN 256

int main(void)
{
    FILE* fp;
    fp = fopen("file.txt", "r");
    if (fp == NULL) {
      perror("Failed: ");
      return 1;
    }

    char buffer[MAX_LEN];
    // -1 to allow room for NULL terminator for really long string
    while (fgets(buffer, MAX_LEN - 1, fp))
    {
        // Remove trailing newline
        buffer[strcspn(buffer, "\n")] = 0;
        printf("%s\n", buffer);
    }

    fclose(fp);
    return 0;
}

Output:

First line of file
Second line of file
Third (and also last) line of file

Remember, if you want to read from Standard Input (rather than a file as in this case), then all you have to do is pass stdin as the third parameter of fgets() method, like this:

while(fgets(buffer, MAX_LEN - 1, stdin))

_Appendix

Removing trailing newline character from fgets() input

how to detect a file is opened or not in c

How to round a numpy array?

If you want the output to be

array([1.6e-01, 9.9e-01, 3.6e-04])

the problem is not really a missing feature of NumPy, but rather that this sort of rounding is not a standard thing to do. You can make your own rounding function which achieves this like so:

def my_round(value, N):
    exponent = np.ceil(np.log10(value))
    return 10**exponent*np.round(value*10**(-exponent), N)

For a general solution handling 0 and negative values as well, you can do something like this:

def my_round(value, N):
    value = np.asarray(value).copy()
    zero_mask = (value == 0)
    value[zero_mask] = 1.0
    sign_mask = (value < 0)
    value[sign_mask] *= -1
    exponent = np.ceil(np.log10(value))
    result = 10**exponent*np.round(value*10**(-exponent), N)
    result[sign_mask] *= -1
    result[zero_mask] = 0.0
    return result

CSS: Control space between bullet and <li>

ul
{
list-style-position:inside;
}

Definition and Usage

The list-style-position property specifies if the list-item markers should appear inside or outside the content flow.

Source: http://www.w3schools.com/cssref/pr_list-style-position.asp

PHP - Fatal error: Unsupported operand types

I had a similar error with the following code:-

foreach($myvar as $key => $value){
    $query = "SELECT stuff
            FROM table
            WHERE col1 = '$criteria1'
            AND col2 = '$criteria2'";

    $result = mysql_query($query) or die('Could not execute query - '.mysql_error(). __FILE__. __LINE__. $query);               
    $point_values = mysql_fetch_assoc($result);
    $top_five_actions[$key] += $point_values; //<--- Problem Line       
}

It turned out that my $point_values variable was occasionally returning false which caused the problem so I fixed it by wrapping it in mysql_num_rows check:-

if(mysql_num_rows($result) > 0) {
        $point_values = mysql_fetch_assoc($result);
        $top_five_actions[$key] += $point_values;
}

Not sure if this helps though?

Cheers

Pandas: Creating DataFrame from Series

I guess anther way, possibly faster, to achieve this is 1) Use dict comprehension to get desired dict (i.e., taking 2nd col of each array) 2) Then use pd.DataFrame to create an instance directly from the dict without loop over each col and concat.

Assuming your mat looks like this (you can ignore this since your mat is loaded from file):

In [135]: mat = {'a': np.random.randint(5, size=(4,2)),
   .....: 'b': np.random.randint(5, size=(4,2))}

In [136]: mat
Out[136]: 
{'a': array([[2, 0],
        [3, 4],
        [0, 1],
        [4, 2]]), 'b': array([[1, 0],
        [1, 1],
        [1, 0],
        [2, 1]])}

Then you can do:

In [137]: df = pd.DataFrame ({name:mat[name][:,1] for name in mat})

In [138]: df
Out[138]: 
   a  b
0  0  0
1  4  1
2  1  0
3  2  1

[4 rows x 2 columns]

How to restore the permissions of files and directories within git if they have been modified?

I use git from cygwin on Windows, the git apply solution doesn't work for me. Here is my solution, run chmod on every file to reset its permissions.

#!/bin/bash
IFS=$'\n'
for c in `git diff -p |sed -n '/diff --git/{N;s/diff --git//g;s/\n/ /g;s# a/.* b/##g;s/old mode //g;s/\(.*\) 100\(.*\)/chmod \2 \1/g;p}'`
do
        eval $c
done
unset IFS

'Class' does not contain a definition for 'Method'

Create class with namespace name might resovle your issue

namespace.Employee employee = new namespace.Employee(); 
employee.ExampleMethod();

What is the purpose and uniqueness SHTML?

It’s just HTML with Server Side Includes.

Partly cherry-picking a commit with Git

If you want to specify a list of files on the command line, and get the whole thing done in a single atomic command, try:

git apply --3way <(git show -- list-of-files)

--3way: If a patch does not apply cleanly, Git will create a merge conflict so you can run git mergetool. Omitting --3way will make Git give up on patches which don't apply cleanly.

How to force Chrome's script debugger to reload javascript?

If you're running a local server on Apache, you can get what look like caching problems. This happened to me when I had a Apache server running under Vagrant (in virtualbox).

Just add the following lines to your config file (/etc/httpd/conf/httpd.conf or equivalent):

#Disable image serving for network mounted drive
EnableSendfile off

Note that it's worth searching through the config file to see if EnableSendfile is set to on anywhere else.

C++ STL Vectors: Get iterator from index?

way mentioned by @dirkgently ( v.begin() + index ) nice and fast for vectors

but std::advance( v.begin(), index ) most generic way and for random access iterators works constant time too.

EDIT
differences in usage:

std::vector<>::iterator it = ( v.begin() + index );

std::vector<>::iterator it = v.begin();
std::advance( it, index );

added after @litb notes.

Why do we check up to the square root of a prime number to determine if it is prime?

Yes, as it was properly explained above, it's enough to iterate up to Math.floor of a number's square root to check its primality (because sqrt covers all possible cases of division; and Math.floor, because any integer above sqrt will already be beyond its range).

Here is a runnable JavaScript code snippet that represents a simple implementation of this approach – and its "runtime-friendliness" is good enough for handling pretty big numbers (I tried checking both prime and not prime numbers up to 10**12, i.e. 1 trillion, compared results with the online database of prime numbers and encountered no errors or lags even on my cheap phone):

_x000D_

function isPrime(num) {
  if (num % 2 === 0 || num < 3 || !Number.isInteger(num)) {
    return num === 2;
  } else {
    const sqrt = Math.floor(Math.sqrt(num));
    for (let i = 3; i <= sqrt; i += 2) {
      if (num % i === 0) {
        return false;
      }
    }
    return true;
  }
}

_x000D_

<label for="inp">Enter a number and click "Check!":</label><br>
<input type="number" id="inp"></input>
<button onclick="alert(isPrime(+document.getElementById('inp').value) ? 'Prime' : 'Not prime')" type="button">Check!</button>

_x000D_

How do I create a datetime in Python from milliseconds?

Converting millis to datetime (UTC):

import datetime
time_in_millis = 1596542285000
dt = datetime.datetime.fromtimestamp(time_in_millis / 1000.0, tz=datetime.timezone.utc)

Converting datetime to string following the RFC3339 standard (used by Open API specification):

from rfc3339 import rfc3339
converted_to_str = rfc3339(dt, utc=True, use_system_timezone=False)
# 2020-08-04T11:58:05Z

How to find first element of array matching a boolean condition in JavaScript?

As of ES 2015, Array.prototype.find() provides for this exact functionality.

For browsers that do not support this feature, the Mozilla Developer Network has provided a polyfill (pasted below):

if (!Array.prototype.find) {
  Array.prototype.find = function(predicate) {
    if (this === null) {
      throw new TypeError('Array.prototype.find called on null or undefined');
    }
    if (typeof predicate !== 'function') {
      throw new TypeError('predicate must be a function');
    }
    var list = Object(this);
    var length = list.length >>> 0;
    var thisArg = arguments[1];
    var value;

    for (var i = 0; i < length; i++) {
      value = list[i];
      if (predicate.call(thisArg, value, i, list)) {
        return value;
      }
    }
    return undefined;
  };
}

Delete files or folder recursively on Windows CMD

For hidden files I had to use the following:

DEL /S /Q /A:H Thumbs.db

What is the purpose of using -pedantic in GCC/G++ compiler?

<-ansi is an obsolete switch that requests the compiler to compile according to the 30-year-old obsolete revision of C standard, ISO/IEC 9899:1990, which is essentially a rebranding of the ANSI standard X3.159-1989 "Programming Language C. Why obsolete? Because after C90 was published by ISO, ISO has been in charge of the C standardization, and any technical corrigenda to C90 have been standardized by ISO. Thus it is more apt to use the -std=c90.

Without this switch, the recent GCC C compilers will conform to the C language standardized in ISO/IEC 9899:2011, or the newest 2018 revision.

Unfortunately there are some lazy compiler vendors that believe it is acceptable to stick to an older obsolete standard revision, for which the standardization document is not even available from standard bodies.

Using the switch helps ensuring that the code should compile in these obsolete compilers.

The -pedantic is an interesting one. In absence of -pedantic, even when a specific standard is requested, GCC will still allow some extensions that are not acceptable in the C standard. Consider for example the program

struct test {
    int zero_size_array[0];
};

The C11 draft n1570 paragraph 6.7.6.2p1 says:

In addition to optional type qualifiers and the keyword static, the [ and ] may delimit an expression or *. If they delimit an expression (which specifies the size of an array), the expression shall have an integer type. If the expression is a constant expression, it shall have a value greater than zero.[...]

The C standard requires that the array length be greater than zero; and this paragraph is in the constraints; the standard says the following 5.1.1.3p1:

A conforming implementation shall produce at least one diagnostic message (identified in an implementation-defined manner) if a preprocessing translation unit or translation unit contains a violation of any syntax rule or constraint, even if the behavior is also explicitly specified as undefined or implementation-defined. Diagnostic messages need not be produced in other circumstances.9)

However, if you compile the program with gcc -c -std=c90 pedantic_test.c, no warning is produced.

-pedantic causes the compiler to actually comply to the C standard; so now it will produce a diagnostic message, as is required by the standard:

gcc -c -pedantic -std=c90 pedantic_test.c
pedantic_test.c:2:9: warning: ISO C forbids zero-size array ‘zero_size_array’ [-Wpedantic]
     int zero_size_array[0];
         ^~~~~~~~~~~~~~~

Thus for maximal portability, specifying the standard revision is not enough, you must also use -pedantic (or -pedantic-errors) to ensure that GCC actually does comply to the letter of the standard.

The last part of the question was about using -ansi with C++. ANSI never standardized the C++ language - only adopting it from ISO, so this makes about as much sense as saying "English as standardized by France". However GCC still seems to accept it for C++, as stupid as it sounds.

ngFor with index as value in attribute

I would use this syntax to set the index value into an attribute of the HTML element:

Angular >= 2

You have to use let to declare the value rather than #.

<ul>
    <li *ngFor="let item of items; let i = index" [attr.data-index]="i">
        {{item}}
    </li>
</ul>

Angular = 1

<ul>
    <li *ngFor="#item of items; #i = index" [attr.data-index]="i">
        {{item}}
    </li>
</ul>

Here is the updated plunkr: http://plnkr.co/edit/LiCeyKGUapS5JKkRWnUJ?p=preview.

Best way to check if a Data Table has a null value in it

I will do like....

(!DBNull.Value.Equals(dataSet.Tables[6].Rows[0]["_id"]))

Why is this inline-block element pushed downward?

SQL Error: ORA-12899: value too large for column

In my case I'm using C# OracleCommand with OracleParameter, and I set all the the parameters Size property to max length of each column, then the error solved.

OracleParameter parm1 = new OracleParameter();
param1.OracleDbType = OracleDbType.Varchar2;
param1.Value = "test1";
param1.Size = 8;

OracleParameter parm2 = new OracleParameter();
param2.OracleDbType = OracleDbType.Varchar2;
param2.Value = "test1";
param2.Size = 12;

Linux find and grep command together

Or maybe even easier

grep -R put **/*bills*

The ** glob syntax means "any depth of directories". It will work in Zsh, and I think recent versions of Bash too.

Shortcut to create properties in Visual Studio?

ReSharper offers property generation in its extensive feature set. (It's not cheap though, unless you're working on an open-source project.)

How to remove specific elements in a numpy array

list comprehension could be an interesting approach as well.

a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])
index = np.array([2, 3, 6]) #index is changed to an array.  
out = [val for i, val in enumerate(a) if all(i != index)]
>>> [1, 2, 5, 6, 8, 9]

Maven: Failed to retrieve plugin descriptor error

I have to put

 <proxy>
  <id>optional</id>
  <active>true</active>
  <protocol>http</protocol>
  <host>Your proxy host</host>
  <port>proxy host ip</port>
  <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
</proxy>

Before

 <proxy>
  <id>optional</id>
  <active>true</active>
  <protocol>https</protocol>
  <host>Your proxy host</host>
  <port>proxy host ip</port>
  <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
</proxy>

Weird, but yes!, <protocol>http</protocol> has to come before <protocol>https</protocol>. It solved my problem. Hope it helps someone who faces connections issue even after enabling proxy settings in conf/settings.xml.

How to capture Curl output to a file?

For a single file you can use -O instead of -o filename to use the last segment of the URL path as the filename. Example:

curl http://example.com/folder/big-file.iso -O

will save the results to a new file named big-file.iso in the current folder. In this way it works similar to wget but allows you to specify other curl options that are not available when using wget.

Using Spring 3 autowire in a standalone Java application

Spring is moving away from XML files and uses annotations heavily. The following example is a simple standalone Spring application which uses annotation instead of XML files.

package com.zetcode.bean;

import org.springframework.stereotype.Component;

@Component
public class Message {

   private String message = "Hello there!";

   public void setMessage(String message){

      this.message  = message;
   }

   public String getMessage(){

      return message;
   }
}

This is a simple bean. It is decorated with the @Component annotation for auto-detection by Spring container.

package com.zetcode.main;

import com.zetcode.bean.Message;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;

@ComponentScan(basePackages = "com.zetcode")
public class Application {

    public static void main(String[] args) {

        ApplicationContext context
                = new AnnotationConfigApplicationContext(Application.class);

        Application p = context.getBean(Application.class);
        p.start();
    }

    @Autowired
    private Message message;
    private void start() {
        System.out.println("Message: " + message.getMessage());
    }
}

This is the main Application class. The @ComponentScan annotation searches for components. The @Autowired annotation injects the bean into the message variable. The AnnotationConfigApplicationContext is used to create the Spring application context.

My Standalone Spring tutorial shows how to create a standalone Spring application with both XML and annotations.

Set space between divs

Float them both the same way and add the margin of 40px. If you have 2 elements floating opposite ways you will have much less control and the containing element will determine how far apart they are.

#left{
    float: left;
    margin-right: 40px;
}
#right{
   float: left;
}

Use 'class' or 'typename' for template parameters?

According to Scott Myers, Effective C++ (3rd ed.) item 42 (which must, of course, be the ultimate answer) - the difference is "nothing".

Advice is to use "class" if it is expected T will always be a class, with "typename" if other types (int, char* whatever) may be expected. Consider it a usage hint.

PHP replacing special characters like à->a, è->e

Here is a way to have some flexibility in what should be discarded and what should be replaced. This is how I currently do it.

$string = 'À some string with junk I Ä ';

$replace = [
    '&lt;' => '', '&gt;' => '', '&#039;' => '', '&amp;' => '',
    '&quot;' => '', 'À' => 'A', 'Á' => 'A', 'Â' => 'A', 'Ã' => 'A', 'Ä' => 'Ae',
    '&Auml;' => 'A', 'Å' => 'A', 'A' => 'A', 'A' => 'A', 'A' => 'A', 'Æ' => 'Ae',
    'Ç' => 'C', 'C' => 'C', 'C' => 'C', 'C' => 'C', 'C' => 'C', 'D' => 'D', 'Ð' => 'D',
    'Ð' => 'D', 'È' => 'E', 'É' => 'E', 'Ê' => 'E', 'Ë' => 'E', 'E' => 'E',
    'E' => 'E', 'E' => 'E', 'E' => 'E', 'E' => 'E', 'G' => 'G', 'G' => 'G',
    'G' => 'G', 'G' => 'G', 'H' => 'H', 'H' => 'H', 'Ì' => 'I', 'Í' => 'I',
    'Î' => 'I', 'Ï' => 'I', 'I' => 'I', 'I' => 'I', 'I' => 'I', 'I' => 'I',
    'I' => 'I', '?' => 'IJ', 'J' => 'J', 'K' => 'K', 'L' => 'K', 'L' => 'K',
    'L' => 'K', 'L' => 'K', '?' => 'K', 'Ñ' => 'N', 'N' => 'N', 'N' => 'N',
    'N' => 'N', '?' => 'N', 'Ò' => 'O', 'Ó' => 'O', 'Ô' => 'O', 'Õ' => 'O',
    'Ö' => 'Oe', '&Ouml;' => 'Oe', 'Ø' => 'O', 'O' => 'O', 'O' => 'O', 'O' => 'O',
    'Œ' => 'OE', 'R' => 'R', 'R' => 'R', 'R' => 'R', 'S' => 'S', 'Š' => 'S',
    'S' => 'S', 'S' => 'S', '?' => 'S', 'T' => 'T', 'T' => 'T', 'T' => 'T',
    '?' => 'T', 'Ù' => 'U', 'Ú' => 'U', 'Û' => 'U', 'Ü' => 'Ue', 'U' => 'U',
    '&Uuml;' => 'Ue', 'U' => 'U', 'U' => 'U', 'U' => 'U', 'U' => 'U', 'U' => 'U',
    'W' => 'W', 'Ý' => 'Y', 'Y' => 'Y', 'Ÿ' => 'Y', 'Z' => 'Z', 'Ž' => 'Z',
    'Z' => 'Z', 'Þ' => 'T', 'à' => 'a', 'á' => 'a', 'â' => 'a', 'ã' => 'a',
    'ä' => 'ae', '&auml;' => 'ae', 'å' => 'a', 'a' => 'a', 'a' => 'a', 'a' => 'a',
    'æ' => 'ae', 'ç' => 'c', 'c' => 'c', 'c' => 'c', 'c' => 'c', 'c' => 'c',
    'd' => 'd', 'd' => 'd', 'ð' => 'd', 'è' => 'e', 'é' => 'e', 'ê' => 'e',
    'ë' => 'e', 'e' => 'e', 'e' => 'e', 'e' => 'e', 'e' => 'e', 'e' => 'e',
    'ƒ' => 'f', 'g' => 'g', 'g' => 'g', 'g' => 'g', 'g' => 'g', 'h' => 'h',
    'h' => 'h', 'ì' => 'i', 'í' => 'i', 'î' => 'i', 'ï' => 'i', 'i' => 'i',
    'i' => 'i', 'i' => 'i', 'i' => 'i', 'i' => 'i', '?' => 'ij', 'j' => 'j',
    'k' => 'k', '?' => 'k', 'l' => 'l', 'l' => 'l', 'l' => 'l', 'l' => 'l',
    '?' => 'l', 'ñ' => 'n', 'n' => 'n', 'n' => 'n', 'n' => 'n', '?' => 'n',
    '?' => 'n', 'ò' => 'o', 'ó' => 'o', 'ô' => 'o', 'õ' => 'o', 'ö' => 'oe',
    '&ouml;' => 'oe', 'ø' => 'o', 'o' => 'o', 'o' => 'o', 'o' => 'o', 'œ' => 'oe',
    'r' => 'r', 'r' => 'r', 'r' => 'r', 'š' => 's', 'ù' => 'u', 'ú' => 'u',
    'û' => 'u', 'ü' => 'ue', 'u' => 'u', '&uuml;' => 'ue', 'u' => 'u', 'u' => 'u',
    'u' => 'u', 'u' => 'u', 'u' => 'u', 'w' => 'w', 'ý' => 'y', 'ÿ' => 'y',
    'y' => 'y', 'ž' => 'z', 'z' => 'z', 'z' => 'z', 'þ' => 't', 'ß' => 'ss',
    '?' => 'ss', '??' => 'iy', '?' => 'A', '?' => 'B', '?' => 'V', '?' => 'G',
    '?' => 'D', '?' => 'E', '?' => 'YO', '?' => 'ZH', '?' => 'Z', '?' => 'I',
    '?' => 'Y', '?' => 'K', '?' => 'L', '?' => 'M', '?' => 'N', '?' => 'O',
    '?' => 'P', '?' => 'R', '?' => 'S', '?' => 'T', '?' => 'U', '?' => 'F',
    '?' => 'H', '?' => 'C', '?' => 'CH', '?' => 'SH', '?' => 'SCH', '?' => '',
    '?' => 'Y', '?' => '', '?' => 'E', '?' => 'YU', '?' => 'YA', '?' => 'a',
    '?' => 'b', '?' => 'v', '?' => 'g', '?' => 'd', '?' => 'e', '?' => 'yo',
    '?' => 'zh', '?' => 'z', '?' => 'i', '?' => 'y', '?' => 'k', '?' => 'l',
    '?' => 'm', '?' => 'n', '?' => 'o', '?' => 'p', '?' => 'r', '?' => 's',
    '?' => 't', '?' => 'u', '?' => 'f', '?' => 'h', '?' => 'c', '?' => 'ch',
    '?' => 'sh', '?' => 'sch', '?' => '', '?' => 'y', '?' => '', '?' => 'e',
    '?' => 'yu', '?' => 'ya'
];

echo str_replace(array_keys($replace), $replace, $string);

It says that TypeError: document.getElementById(...) is null

I got the same error. In my case I had multiple div with same id in a page. I renamed the another id of the div used and fixed the issue.

So confirm whether the element:

exists with id
doesn't have duplicate with id
confirm whether the script is called

How to center the text in a JLabel?

String text = "In early March, the city of Topeka, Kansas," + "<br>" +
              "temporarily changed its name to Google..." + "<br>" + "<br>" +
              "...in an attempt to capture a spot" + "<br>" +
              "in Google's new broadband/fiber-optics project." + "<br>" + "<br>" +"<br>" +
              "source: http://en.wikipedia.org/wiki/Google_server#Oil_Tanker_Data_Center";
JLabel label = new JLabel("<html><div style='text-align: center;'>" + text + "</div></html>");

Spring Boot application as a Service

I just got around to doing this myself, so the following is where I am so far in terms of a CentOS init.d service controller script. It's working quite nicely so far, but I'm no leet Bash hacker, so I'm sure there's room for improvement, so thoughts on improving it are welcome.

First of all, I have a short config script /data/svcmgmt/conf/my-spring-boot-api.sh for each service, which sets up environment variables.

#!/bin/bash
export JAVA_HOME=/opt/jdk1.8.0_05/jre
export APP_HOME=/data/apps/my-spring-boot-api
export APP_NAME=my-spring-boot-api
export APP_PORT=40001

I'm using CentOS, so to ensure that my services are started after a server restart, I have a service control script in /etc/init.d/my-spring-boot-api:

#!/bin/bash
# description: my-spring-boot-api start stop restart
# processname: my-spring-boot-api
# chkconfig: 234 20 80

. /data/svcmgmt/conf/my-spring-boot-api.sh

/data/svcmgmt/bin/spring-boot-service.sh $1

exit 0

As you can see, that calls the initial config script to set up environment variables and then calls a shared script which I use for restarting all of my Spring Boot services. That shared script is where the meat of it all can be found:

#!/bin/bash

echo "Service [$APP_NAME] - [$1]"

echo "    JAVA_HOME=$JAVA_HOME"
echo "    APP_HOME=$APP_HOME"
echo "    APP_NAME=$APP_NAME"
echo "    APP_PORT=$APP_PORT"

function start {
    if pkill -0 -f $APP_NAME.jar > /dev/null 2>&1
    then
        echo "Service [$APP_NAME] is already running. Ignoring startup request."
        exit 1
    fi
    echo "Starting application..."
    nohup $JAVA_HOME/bin/java -jar $APP_HOME/$APP_NAME.jar \
        --spring.config.location=file:$APP_HOME/config/   \
        < /dev/null > $APP_HOME/logs/app.log 2>&1 &
}

function stop {
    if ! pkill -0 -f $APP_NAME.jar > /dev/null 2>&1
    then
        echo "Service [$APP_NAME] is not running. Ignoring shutdown request."
        exit 1
    fi

    # First, we will try to trigger a controlled shutdown using 
    # spring-boot-actuator
    curl -X POST http://localhost:$APP_PORT/shutdown < /dev/null > /dev/null 2>&1

    # Wait until the server process has shut down
    attempts=0
    while pkill -0 -f $APP_NAME.jar > /dev/null 2>&1
    do
        attempts=$[$attempts + 1]
        if [ $attempts -gt 5 ]
        then
            # We have waited too long. Kill it.
            pkill -f $APP_NAME.jar > /dev/null 2>&1
        fi
        sleep 1s
    done
}

case $1 in
start)
    start
;;
stop)
    stop
;;
restart)
    stop
    start
;;
esac
exit 0

When stopping, it will attempt to use Spring Boot Actuator to perform a controlled shutdown. However, in case Actuator is not configured or fails to shut down within a reasonable time frame (I give it 5 seconds, which is a bit short really), the process will be killed.

Also, the script makes the assumption that the java process running the appllication will be the only one with "my-spring-boot-api.jar" in the text of the process details. This is a safe assumption in my environment and means that I don't need to keep track of PIDs.

php - get numeric index of associative array


  $a = array(
      'blue' => 'nice',
      'car' => 'fast',
      'number' => 'none'
  );  
var_dump(array_search('car', array_keys($a)));
var_dump(array_search('blue', array_keys($a)));
var_dump(array_search('number', array_keys($a)));

Using the Underscore module with Node.js

Or :

    var _ = require('underscore')._;

Where does PHP store the error log? (php5, apache, fastcgi, cpanel)

On a LAMP environment the php errors are default directed to this below file.

/var/log/httpd/error_log

All access logs come under:

/var/log/httpd/access_log

Why does overflow:hidden not work in a <td>?

Here is the same problem.

You need to set table-layout:fixed and a suitable width on the table element, as well as overflow:hidden and white-space: nowrap on the table cells.

Examples

Fixed width columns

The width of the table has to be the same (or smaller) than the fixed width cell(s).

With one fixed width column:

_x000D_

* {
  box-sizing: border-box;
}
table {
  table-layout: fixed;
  border-collapse: collapse;
  width: 100%;
  max-width: 100px;
}
td {
  background: #F00;
  padding: 20px;
  overflow: hidden;
  white-space: nowrap;
  width: 100px;
  border: solid 1px #000;
}

_x000D_

<table>
  <tbody>
    <tr>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
    </tr>
    <tr>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
    </tr>
  </tbody>
</table>

_x000D_

With multiple fixed width columns:

_x000D_

* {
  box-sizing: border-box;
}
table {
  table-layout: fixed;
  border-collapse: collapse;
  width: 100%;
  max-width: 200px;
}
td {
  background: #F00;
  padding: 20px;
  overflow: hidden;
  white-space: nowrap;
  width: 100px;
  border: solid 1px #000;
}

_x000D_

<table>
  <tbody>
    <tr>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
    </tr>
    <tr>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
    </tr>
  </tbody>
</table>

_x000D_

Fixed and fluid width columns

A width for the table must be set, but any extra width is simply taken by the fluid cell(s).

With multiple columns, fixed width and fluid width:

_x000D_

* {
  box-sizing: border-box;
}
table {
  table-layout: fixed;
  border-collapse: collapse;
  width: 100%;
}
td {
  background: #F00;
  padding: 20px;
  border: solid 1px #000;
}
tr td:first-child {
  overflow: hidden;
  white-space: nowrap;
  width: 100px;
}

_x000D_

<table>
  <tbody>
    <tr>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
    </tr>
    <tr>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
      <td>
        This_is_a_terrible_example_of_thinking_outside_the_box.
      </td>
    </tr>
  </tbody>
</table>

_x000D_

ASP.Net which user account running Web Service on IIS 7?

I had a ton of trouble with this and then found a great solution:

Create a file in a text editor called whoami.php with the below code as it's content, save the file and upload it to public_html (or whatever you root of your webserver directory is named). It should output a useful string that you can use to track down the user the webserver is running as, my output was "php is running as user: nt authority\iusr" which allowed me to track down the permissions I needed to modify to the user "IUSR".

<?php
  // outputs the username that owns the running php/httpd process
  // (on a system with the "whoami" executable in the path)
  echo 'php is running as user: ' . exec('whoami');
?>

vertical-align: middle doesn't work

You should set a fixed value to your span's line-height property:

.float, .twoline {
    line-height: 100px;
}

Find the index of a char in string?

Contanis occur if using the method of the present letter, and store the corresponding number using the IndexOf method, see example below.

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim myString As String = "abcdef"
    Dim numberString As String = String.Empty

    If myString.Contains("d") Then
        numberString = myString.IndexOf("d")
    End If
End Sub

Another sample with TextBox

  Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    Dim myString As String = "abcdef"
    Dim numberString As String = String.Empty

    If myString.Contains(me.TextBox1.Text) Then
        numberString = myString.IndexOf(Me.TextBox1.Text)
    End If
End Sub

Regards

How to use opencv in using Gradle?

You can do this very easily in Android Studio.

Follow the below steps to add Open CV in your project as library.

Create a libraries folder underneath your project main directory. For example, if your project is OpenCVExamples, you would create a OpenCVExamples/libraries folder.
Go to the location where you have SDK "\OpenCV-2.4.8-android-sdk\sdk" here you will find the java folder, rename it to opencv.
Now copy the complete opencv directory from the SDK into the libraries folder you just created.

Now create a build.gradle file in the opencv directory with the following contents

apply plugin: 'android-library'

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.9.+'
    }
}

android {
    compileSdkVersion 19
    buildToolsVersion "19.0.1"

    defaultConfig {
        minSdkVersion 8
        targetSdkVersion 19
        versionCode 2480
        versionName "2.4.8"
    }

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            res.srcDirs = ['res']
            aidl.srcDirs = ['src']
        }
    }
}

Edit your settings.gradle file in your application’s main directory and add this line:
```
include ':libraries:opencv'
```
Sync your project with Gradle and it should looks like this
Right click on your project then click on the Open Module Settings then Choose Modules from the left-hand list, click on your application’s module, click on the Dependencies tab, and click on the + button to add a new module dependency.
Choose Module dependency. It will open a dialog with a list of modules to choose from; select “:libraries:opencv”.
Create a jniLibs folder in the /app/src/main/ location and copy the all the folder with *.so files (armeabi, armeabi-v7a, mips, x86) in the jniLibs from the OpenCV SDK.
Click OK. Now everything done, go and enjoy with OpenCV.

Calculate business days

An enhancement to the function offered by James Pasta above, to include all Federal Holidays, and to correct 4th July (was calculated as 4th June above!), and to also include the holiday name as the array key...

/**
* National American Holidays
* @param string $year
* @return array
*/
public static function getNationalAmericanHolidays($year) {

//  January 1 - New Year's Day (Observed)
//  Third Monday in January - Birthday of Martin Luther King, Jr.
//  Third Monday in February - Washington’s Birthday / President's Day
//  Last Monday in May - Memorial Day
//  July 4 - Independence Day
//  First Monday in September - Labor Day
//  Second Monday in October - Columbus Day
//  November 11 - Veterans’ Day (Observed)
//  Fourth Thursday in November Thanksgiving Day
//  December 25 - Christmas Day
$bankHolidays = array(
    ['New Years Day'] => $year . "-01-01",
    ['Martin Luther King Jr Birthday'] => "". date("Y-m-d",strtotime("third Monday of January " . $year) ),
    ['Washingtons Birthday'] => "". date("Y-m-d",strtotime("third Monday of February " . $year) ),
    ['Memorial Day'] => "". date("Y-m-d",strtotime("last Monday of May " . $year) ),
    ['Independance Day'] => $year . "-07-04",
    ['Labor Day'] => "". date("Y-m-d",strtotime("first Monday of September " . $year) ),
    ['Columbus Day'] => "". date("Y-m-d",strtotime("second Monday of October " . $year) ),
    ['Veterans Day'] => $year . "-11-11",
    ['Thanksgiving Day'] => "". date("Y-m-d",strtotime("fourth Thursday of November " . $year) ),
    ['Christmas Day'] => $year . "-12-25"
);

return $bankHolidays;

}

How do I configure IIS for URL Rewriting an AngularJS application in HTML5 mode?

In my case I kept getting a 403.14 after I had setup the correct rewrite rules. It turns out that I had a directory that was the same name as one of my URL routes. Once I removed the IsDirectory rewrite rule my routes worked correctly. Is there a case where removing the directory negation may cause problems? I can't think of any in my case. The only case I can think of is if you can browse a directory with your app.

<rule name="fixhtml5mode" stopProcessing="true">
  <match url=".*"/>
  <conditions logicalGrouping="MatchAll">
    <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
  </conditions>
  <action type="Rewrite" url="/" />
</rule>

Error:Unable to locate adb within SDK in Android Studio

In my case I had no SDK selected for my project(not sure why). Simply went to Project Structure dialog (alt+ctrl+shift+s or button 1 on the screen) and then to project-> Project SDK's was selected <no SDK>. Just changed it to the latest

How to create Haar Cascade (.xml file) to use in OpenCV?

If you are interested to detect simple IR light blob through haar cascade, it will be very odd to do. Because simple IR blob does not have enough features to be trained through opencv like other objects (face, eyes,nose etc). Because IR is just a simple light having only one feature of brightness in my point of view. But if you want to learn how to train a classifier following link will help you alot.

http://note.sonots.com/SciSoftware/haartraining.html

And if you just want to detect IR blob, then you have two more possibilities, one is you go for DIP algorithms to detect bright region and the other one which I recommend you is you can use an IR cam which just pass the IR blob and you can detect easily the IR blob by using opencv blob functiuons. If you think an IR cam is expansive, you can make simple webcam to an IR cam by removing IR blocker (if any) and add visible light blocker i.e negative film, floppy material or any other. You can check the following link to convert simple webcam to IR cam.

http://www.metacafe.com/watch/385098/transform_your_webcam_into_an_infrared_cam/

.prop() vs .attr()

Update 1 November 2012

My original answer applies specifically to jQuery 1.6. My advice remains the same but jQuery 1.6.1 changed things slightly: in the face of the predicted pile of broken websites, the jQuery team reverted attr() to something close to (but not exactly the same as) its old behaviour for Boolean attributes. John Resig also blogged about it. I can see the difficulty they were in but still disagree with his recommendation to prefer attr().

Original answer

If you've only ever used jQuery and not the DOM directly, this could be a confusing change, although it is definitely an improvement conceptually. Not so good for the bazillions of sites using jQuery that will break as a result of this change though.

I'll summarize the main issues:

You usually want prop() rather than attr().
In the majority of cases, prop() does what attr() used to do. Replacing calls to attr() with prop() in your code will generally work.
Properties are generally simpler to deal with than attributes. An attribute value may only be a string whereas a property can be of any type. For example, the checked property is a Boolean, the style property is an object with individual properties for each style, the size property is a number.
Where both a property and an attribute with the same name exists, usually updating one will update the other, but this is not the case for certain attributes of inputs, such as value and checked: for these attributes, the property always represents the current state while the attribute (except in old versions of IE) corresponds to the default value/checkedness of the input (reflected in the defaultValue / defaultChecked property).
This change removes some of the layer of magic jQuery stuck in front of attributes and properties, meaning jQuery developers will have to learn a bit about the difference between properties and attributes. This is a good thing.

If you're a jQuery developer and are confused by this whole business about properties and attributes, you need to take a step back and learn a little about it, since jQuery is no longer trying so hard to shield you from this stuff. For the authoritative but somewhat dry word on the subject, there's the specs: DOM4, HTML DOM, DOM Level 2, DOM Level 3. Mozilla's DOM documentation is valid for most modern browsers and is easier to read than the specs, so you may find their DOM reference helpful. There's a section on element properties.

As an example of how properties are simpler to deal with than attributes, consider a checkbox that is initially checked. Here are two possible pieces of valid HTML to do this:

<input id="cb" type="checkbox" checked>
<input id="cb" type="checkbox" checked="checked">

So, how do you find out if the checkbox is checked with jQuery? Look on Stack Overflow and you'll commonly find the following suggestions:

if ( $("#cb").attr("checked") === true ) {...}
if ( $("#cb").attr("checked") == "checked" ) {...}
if ( $("#cb").is(":checked") ) {...}

This is actually the simplest thing in the world to do with the checked Boolean property, which has existed and worked flawlessly in every major scriptable browser since 1995:

if (document.getElementById("cb").checked) {...}

The property also makes checking or unchecking the checkbox trivial:

document.getElementById("cb").checked = false

In jQuery 1.6, this unambiguously becomes

$("#cb").prop("checked", false)

The idea of using the checked attribute for scripting a checkbox is unhelpful and unnecessary. The property is what you need.

It's not obvious what the correct way to check or uncheck the checkbox is using the checked attribute
The attribute value reflects the default rather than the current visible state (except in some older versions of IE, thus making things still harder). The attribute tells you nothing about the whether the checkbox on the page is checked. See http://jsfiddle.net/VktA6/49/.

Rails 4 - passing variable to partial

If you are using JavaScript to render then use escape_JavaScript("<%=render partial: partial_name, locals=>{@newval=>@oldval}%>");

Running command line silently with VbScript and getting output?

Dim path As String = GetFolderPath(SpecialFolder.ApplicationData)
 Dim filepath As String = path + "\" + "your.bat"
    ' Create the file if it does not exist. 
    If File.Exists(filepath) = False Then
        File.Create(filepath)
    Else
    End If
    Dim attributes As FileAttributes
    attributes = File.GetAttributes(filepath)
    If (attributes And FileAttributes.ReadOnly) = FileAttributes.ReadOnly Then
        ' Remove from Readonly the file.
        attributes = RemoveAttribute(attributes, FileAttributes.ReadOnly)
        File.SetAttributes(filepath, attributes)
        Console.WriteLine("The {0} file is no longer RO.", filepath)
    Else
    End If
    If (attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
        ' Show the file.
        attributes = RemoveAttribute(attributes, FileAttributes.Hidden)
        File.SetAttributes(filepath, attributes)
        Console.WriteLine("The {0} file is no longer Hidden.", filepath)
    Else
    End If
    Dim sr As New StreamReader(filepath)
    Dim input As String = sr.ReadToEnd()
    sr.Close()
    Dim output As String = "@echo off"
    Dim output1 As String = vbNewLine + "your 1st cmd code"
    Dim output2 As String = vbNewLine + "your 2nd cmd code "
    Dim output3 As String = vbNewLine + "exit"
    Dim sw As New StreamWriter(filepath)
    sw.Write(output)
    sw.Write(output1)
    sw.Write(output2)
    sw.Write(output3)
    sw.Close()
    If (attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
    Else
        ' Hide the file.
        File.SetAttributes(filepath, File.GetAttributes(filepath) Or FileAttributes.Hidden)
        Console.WriteLine("The {0} file is now hidden.", filepath)
    End If
    Dim procInfo As New ProcessStartInfo(path + "\" + "your.bat")
    procInfo.WindowStyle = ProcessWindowStyle.Minimized
    procInfo.WindowStyle = ProcessWindowStyle.Hidden
    procInfo.CreateNoWindow = True
    procInfo.FileName = path + "\" + "your.bat"
    procInfo.Verb = "runas"
    Process.Start(procInfo)

it saves your .bat file to "Appdata of current user" ,if it does not exist and remove the attributes and after that set the "hidden" attributes to file after writing your cmd code and run it silently and capture all output saves it to file so if u wanna save all output of cmd to file just add your like this

code > C:\Users\Lenovo\Desktop\output.txt

just replace word "code" with your .bat file code or command and after that the directory of output file I found one code recently after searching alot if u wanna run .bat file in vb or c# or simply just add this in the same manner in which i have written

Special characters like @ and & in cURL POST data

I did this

~]$ export A=g

~]$ export B=!

~]$ export C=nger


   curl http://<>USERNAME<>1:$A$B$C@<>URL<>/<>PATH<>/

How to add a border to a widget in Flutter?

Using BoxDecoration() is the best way to show border.

Container(
  decoration: BoxDecoration(
    border: Border.all(
    color: Color(0xff000000),
    width: 4,
  )),
  child: //Your child widget
),

You can also view full format here

What are the differences between "git commit" and "git push"?

Just want to add the following points:

Yon can not push until you commit as we use git push to push commits made on your local branch to a remote repository.

The git push command takes two arguments:

A remote name, for example, origin A branch name, for example, master

For example:

git push  <REMOTENAME> <BRANCHNAME> 
git push  origin       master

Plot size and resolution with R markdown, knitr, pandoc, beamer

Figure sizes are specified in inches and can be included as a global option of the document output format. For example:

---
title: "My Document"
output:
  html_document:
    fig_width: 6
    fig_height: 4
---

And the plot's size in the graphic device can be increased at the chunk level:

```{r, fig.width=14, fig.height=12}          #Expand the plot width to 14 inches

ggplot(aes(x=mycolumn1, y=mycolumn2)) +     #specify the x and y aesthetic
geom_line(size=2) +                         #makes the line thicker
theme_grey(base_size = 25)                  #increases the size of the font
```

You can also use the out.width and out.height arguments to directly define the size of the plot in the output file:

```{r, out.width="200px", out.height="200px"} #Expand the plot width to 200 pixels

ggplot(aes(x=mycolumn1, y=mycolumn2)) +     #specify the x and y aesthetic
geom_line(size=2) +                         #makes the line thicker
theme_grey(base_size = 25)                  #increases the size of the font
```

UnsatisfiedDependencyException: Error creating bean with name

If you describe a field as criteria in method definition ("findBy"), You must pass that parameter to the method, otherwise you will get "Unsatisfied dependency expressed through method parameter" exception.

public interface ClientRepository extends JpaRepository<Client, Integer> {
       Client findByClientId();                ////WRONG !!!!
       Client findByClientId(int clientId);    /// CORRECT 
}

*I assume that your Client entity has clientId attribute.

Python, Matplotlib, subplot: How to set the axis range?

If you have multiple subplots, i.e.

fig, ax = plt.subplots(4, 2)

You can use the same y limits for all of them. It gets limits of y ax from first plot.

plt.setp(ax, ylim=ax[0,0].get_ylim())

Find unused code

ReSharper does a great job of finding unused code.

In the VS IDE, you can right click on the definition and choose 'Find All References', although this only works at the solution level.

Returning a value even if no result

Do search with LEFT OUTER JOIN. I don't know if MySQL allows inline VALUES in join clauses but you can have predefined table for this purposes.

Understanding dict.copy() - shallow or deep?

In your second part, you should use new = original.copy()

.copy and = are different things.

How can I get the client's IP address in ASP.NET MVC?

A lot of the code here was very helpful, but I cleaned it up for my purposes and added some tests. Here's what I ended up with:

using System;
using System.Linq;
using System.Net;
using System.Web;

public class RequestHelpers
{
    public static string GetClientIpAddress(HttpRequestBase request)
    {
        try
        {
            var userHostAddress = request.UserHostAddress;

            // Attempt to parse.  If it fails, we catch below and return "0.0.0.0"
            // Could use TryParse instead, but I wanted to catch all exceptions
            IPAddress.Parse(userHostAddress);

            var xForwardedFor = request.ServerVariables["X_FORWARDED_FOR"];

            if (string.IsNullOrEmpty(xForwardedFor))
                return userHostAddress;

            // Get a list of public ip addresses in the X_FORWARDED_FOR variable
            var publicForwardingIps = xForwardedFor.Split(',').Where(ip => !IsPrivateIpAddress(ip)).ToList();

            // If we found any, return the last one, otherwise return the user host address
            return publicForwardingIps.Any() ? publicForwardingIps.Last() : userHostAddress;
        }
        catch (Exception)
        {
            // Always return all zeroes for any failure (my calling code expects it)
            return "0.0.0.0";
        }
    }

    private static bool IsPrivateIpAddress(string ipAddress)
    {
        // http://en.wikipedia.org/wiki/Private_network
        // Private IP Addresses are: 
        //  24-bit block: 10.0.0.0 through 10.255.255.255
        //  20-bit block: 172.16.0.0 through 172.31.255.255
        //  16-bit block: 192.168.0.0 through 192.168.255.255
        //  Link-local addresses: 169.254.0.0 through 169.254.255.255 (http://en.wikipedia.org/wiki/Link-local_address)

        var ip = IPAddress.Parse(ipAddress);
        var octets = ip.GetAddressBytes();

        var is24BitBlock = octets[0] == 10;
        if (is24BitBlock) return true; // Return to prevent further processing

        var is20BitBlock = octets[0] == 172 && octets[1] >= 16 && octets[1] <= 31;
        if (is20BitBlock) return true; // Return to prevent further processing

        var is16BitBlock = octets[0] == 192 && octets[1] == 168;
        if (is16BitBlock) return true; // Return to prevent further processing

        var isLinkLocalAddress = octets[0] == 169 && octets[1] == 254;
        return isLinkLocalAddress;
    }
}

And here are some NUnit tests against that code (I'm using Rhino Mocks to mock the HttpRequestBase, which is the M<HttpRequestBase> call below):

using System.Web;
using NUnit.Framework;
using Rhino.Mocks;
using Should;

[TestFixture]
public class HelpersTests : TestBase
{
    HttpRequestBase _httpRequest;

    private const string XForwardedFor = "X_FORWARDED_FOR";
    private const string MalformedIpAddress = "MALFORMED";
    private const string DefaultIpAddress = "0.0.0.0";
    private const string GoogleIpAddress = "74.125.224.224";
    private const string MicrosoftIpAddress = "65.55.58.201";
    private const string Private24Bit = "10.0.0.0";
    private const string Private20Bit = "172.16.0.0";
    private const string Private16Bit = "192.168.0.0";
    private const string PrivateLinkLocal = "169.254.0.0";

    [SetUp]
    public void Setup()
    {
        _httpRequest = M<HttpRequestBase>();
    }

    [TearDown]
    public void Teardown()
    {
        _httpRequest = null;
    }

    [Test]
    public void PublicIpAndNullXForwardedFor_Returns_CorrectIp()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(null);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(GoogleIpAddress);
    }

    [Test]
    public void PublicIpAndEmptyXForwardedFor_Returns_CorrectIp()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(string.Empty);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(GoogleIpAddress);
    }

    [Test]
    public void MalformedUserHostAddress_Returns_DefaultIpAddress()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(MalformedIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(null);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(DefaultIpAddress);
    }

    [Test]
    public void MalformedXForwardedFor_Returns_DefaultIpAddress()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(MalformedIpAddress);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(DefaultIpAddress);
    }

    [Test]
    public void SingleValidPublicXForwardedFor_Returns_XForwardedFor()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(MicrosoftIpAddress);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(MicrosoftIpAddress);
    }

    [Test]
    public void MultipleValidPublicXForwardedFor_Returns_LastXForwardedFor()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(GoogleIpAddress + "," + MicrosoftIpAddress);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(MicrosoftIpAddress);
    }

    [Test]
    public void SinglePrivateXForwardedFor_Returns_UserHostAddress()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(Private24Bit);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(GoogleIpAddress);
    }

    [Test]
    public void MultiplePrivateXForwardedFor_Returns_UserHostAddress()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        const string privateIpList = Private24Bit + "," + Private20Bit + "," + Private16Bit + "," + PrivateLinkLocal;
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(privateIpList);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(GoogleIpAddress);
    }

    [Test]
    public void MultiplePublicXForwardedForWithPrivateLast_Returns_LastPublic()
    {
        // Arrange
        _httpRequest.Stub(x => x.UserHostAddress).Return(GoogleIpAddress);
        const string privateIpList = Private24Bit + "," + Private20Bit + "," + MicrosoftIpAddress + "," + PrivateLinkLocal;
        _httpRequest.Stub(x => x.ServerVariables[XForwardedFor]).Return(privateIpList);

        // Act
        var ip = RequestHelpers.GetClientIpAddress(_httpRequest);

        // Assert
        ip.ShouldEqual(MicrosoftIpAddress);
    }
}

What are the use cases for selecting CHAR over VARCHAR in SQL?

Using CHAR (NCHAR) and VARCHAR (NVARCHAR) brings differences in the ways the database server stores the data. The first one introduces trailing blanks; I have encountered problem when using it with LIKE operator in SQL SERVER functions. So I have to make it safe by using VARCHAR (NVARCHAR) all the times.

For example, if we have a table TEST(ID INT, Status CHAR(1)), and you write a function to list all the records with some specific value like the following:

CREATE FUNCTION List(@Status AS CHAR(1) = '')
RETURNS TABLE
AS
RETURN
SELECT * FROM TEST
WHERE Status LIKE '%' + @Status '%'

In this function we expect that when we put the default parameter the function will return all the rows, but in fact it does not. Change the @Status data type to VARCHAR will fix the issue.

How to get parameters from the URL with JSP

www.somesite.com/Transaction_List.jsp?accountID=5

For this URL there is a method call request.getParameter in java , if you want a number here cast into int, similarly for string value cast into string. so for your requirement , just copy past below line in page,

int  accountId =(int)request.getParameter("accountID");

you can now call this value useing accountId in whole page.

here accountId is name of parameter you can also get more than one parameters using this, but this not work. It will only work with GET method if you hit POST request then their will be an error.

Hope this is helpful.

String delimiter in string.split method

Double quotes are interpreted as literals in regex; they are not special characters. You are trying to match a literal "||".

Just use Pattern.quote(delimiter):

As requested, here's a line of code (same as Sanjay's)

final String[] tokens = line.split(Pattern.quote(delimiter));

If that doesn't work, you're not passing in the correct delimiter.

Change form size at runtime in C#

As a complement to the answers given above; do not forget about Form MinimumSize Property, in case you require to create smaller Forms.

Example Bellow:

private void SetDefaultWindowSize()
{
   int sizeW, sizeH;
   sizeW = 180;
   sizeH = 100;

   var size = new Size(sizeW, sizeH);

   Size = size;
   MinimumSize = size;
}

private void SetNewSize()
{
   Size = new Size(Width, 10);
}

Are table names in MySQL case sensitive?

It depends upon lower_case_table_names system variable:

show variables where Variable_name='lower_case_table_names'

There are three possible values for this:

0 - lettercase specified in the CREATE TABLE or CREATE DATABASE statement. Name comparisons are case sensitive.
1 - Table names are stored in lowercase on disk and name comparisons are not case sensitive.
2 - lettercase specified in the CREATE TABLE or CREATE DATABASE statement, but MySQL converts them to lowercase on lookup. Name comparisons are not case sensitive.

Documentation

Get resultset from oracle stored procedure

In SQL Plus:

SQL> create procedure myproc (prc out sys_refcursor)
  2  is
  3  begin
  4     open prc for select * from emp;
  5  end;
  6  /

Procedure created.

SQL> var rc refcursor
SQL> execute myproc(:rc)

PL/SQL procedure successfully completed.

SQL> print rc

     EMPNO ENAME      JOB              MGR HIREDATE           SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ----------- ---------- ---------- ----------
      7839 KING       PRESIDENT            17-NOV-1981       4999                    10
      7698 BLAKE      MANAGER         7839 01-MAY-1981       2849                    30
      7782 CLARKE     MANAGER         7839 09-JUN-1981       2449                    10
      7566 JONES      MANAGER         7839 02-APR-1981       2974                    20
      7788 SCOTT      ANALYST         7566 09-DEC-1982       2999                    20
      7902 FORD       ANALYST         7566 03-DEC-1981       2999                    20
      7369 SMITHY     CLERK           7902 17-DEC-1980       9988         11         20
      7499 ALLEN      SALESMAN        7698 20-FEB-1981       1599       3009         30
      7521 WARDS      SALESMAN        7698 22-FEB-1981       1249        551         30
      7654 MARTIN     SALESMAN        7698 28-SEP-1981       1249       1400         30
      7844 TURNER     SALESMAN        7698 08-SEP-1981       1499          0         30
      7876 ADAMS      CLERK           7788 12-JAN-1983       1099                    20
      7900 JAMES      CLERK           7698 03-DEC-1981        949                    30
      7934 MILLER     CLERK           7782 23-JAN-1982       1299                    10
      6668 Umberto    CLERK           7566 11-JUN-2009      19999          0         10
      9567 ALLBRIGHT  ANALYST         7788 02-JUN-2009      76999         24         10

How to declare strings in C

Strings in C are represented as arrays of characters.

char *p = "String";

You are declaring a pointer that points to a string stored some where in your program (modifying this string is undefined behavior) according to the C programming language 2 ed.

char p2[] = "String";

You are declaring an array of char initialized with the string "String" leaving to the compiler the job to count the size of the array.

char p3[5] = "String";

You are declaring an array of size 5 and initializing it with "String". This is an error be cause "String" don't fit in 5 elements.

char p3[7] = "String"; is the correct declaration ('\0' is the terminating character in c strings).

http://c-faq.com/~scs/cclass/notes/sx8.html

How can I easily convert DataReader to List<T>?

The simplest Solution :

var dt=new DataTable();
dt.Load(myDataReader);
list<DataRow> dr=dt.AsEnumerable().ToList();

Detect if the device is iPhone X

There are several reasons to want to know what the device is.

You can check the device height (and width). This is useful for layout, but you usually don't want to do that if you want to know the exact device.
For layout purposes, you can also use UIView.safeAreaInsets.
If you want to display the device name, for example, to be included in a email for diagnostic purposes, after retrieving the device model using sysctl (), you can use the equivalent of this to figure the name:
```
$ curl http://appledevicenames.com/devices/iPhone10,6

iPhone X
```

Python: One Try Multiple Except

Yes, it is possible.

try:
   ...
except FirstException:
   handle_first_one()

except SecondException:
   handle_second_one()

except (ThirdException, FourthException, FifthException) as e:
   handle_either_of_3rd_4th_or_5th()

except Exception:
   handle_all_other_exceptions()

See: http://docs.python.org/tutorial/errors.html

The "as" keyword is used to assign the error to a variable so that the error can be investigated more thoroughly later on in the code. Also note that the parentheses for the triple exception case are needed in python 3. This page has more info: Catch multiple exceptions in one line (except block)

Replace first occurrence of string in Python

Use re.sub directly, this allows you to specify a count:

regex.sub('', url, 1)

(Note that the order of arguments is replacement, original not the opposite, as might be suspected.)

Adding image inside table cell in HTML

Sould look like:

<td colspan ='4'><img src="\Pics\H.gif" alt="" border='3' height='100' width='100' /></td>

<td> need to be closed with </td> <img /> is (in most case) an empty tag. The closing tag is replacede by /> instead... like for br's

<br/>

Your html structure is plain worng (sorry), but this will probably turn into a really bad cross-brwoser compatibility. Also, Encapsulate the value of your attributes with quotes and avoid using upercase in tags.

Activity, AppCompatActivity, FragmentActivity, and ActionBarActivity: When to Use Which?

Since the name is likely to change in future versions of Android (currently the latest is AppCompatActivity but it will probably change at some point), I believe a good thing to have is a class Activity that extends AppCompatActivity and then all your activities extend from that one. If tomorrow, they change the name to AppCompatActivity2 for instance you will have to change it just in one place.

Android camera android.hardware.Camera deprecated

Now we have to use android.hardware.camera2 as android.hardware.Camera is deprecated which will only work on API >23 FlashLight

   public class MainActivity extends AppCompatActivity {

     Button button;

     Boolean light=true;

     CameraDevice cameraDevice;

     private CameraManager cameraManager;

     private CameraCharacteristics cameraCharacteristics;

     String cameraId;

     @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button=(Button)findViewById(R.id.button);
        cameraManager = (CameraManager) 
        getSystemService(Context.CAMERA_SERVICE);
        try {
          cameraId = cameraManager.getCameraIdList()[0];
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(light){
                    try {

                        cameraManager.setTorchMode(cameraId,true);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }

                    light=false;}
                    else {

                    try {

                      cameraManager.setTorchMode(cameraId,false);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }


                    light=true;
                    }


            }
        });
    }
}

SQLiteDatabase.query method

db.query(
        TABLE_NAME,
        new String[] { TABLE_ROW_ID, TABLE_ROW_ONE, TABLE_ROW_TWO },
        TABLE_ROW_ID + "=" + rowID,
        null, null, null, null, null
);

TABLE_ROW_ID + "=" + rowID, here = is the where clause. To select all values you will have to give all column names:

or you can use a raw query like this 
db.rawQuery("SELECT * FROM permissions_table WHERE name = 'Comics' ", null);

and here is a good tutorial for database.

How different is Objective-C from C++?

Off the top of my head:

Styles - Obj-C is dynamic, C++ is typically static
Although they are both OOP, I'm certain the solutions would be different.
Different object model (C++ is restricted by its compile-time type system).

To me, the biggest difference is the model system. Obj-C lets you do messaging and introspection, but C++ has the ever-so-powerful templates.

Each have their strengths.

MS-DOS Batch file pause with enter key

The only valid answer would be the pause command.

Though this does not wait specifically for the 'ENTER' key, it waits for any key that is pressed.

And just in case you want it convenient for the user, pause is the best option.

How can I test if a letter in a string is uppercase or lowercase using JavaScript?

This is straightforward, readable solution using a simple regex.

// Get specific char in string
const char = string.charAt(index);

const isLowerCaseLetter = (/[a-z]/.test(char));
const isUpperCaseLetter = (/[A-Z]/.test(char));

Python Matplotlib figure title overlaps axes label when using twiny

I was having an issue with the x-label overlapping a subplot title; this worked for me:

import matplotlib.pyplot as plt
fig, ax = plt.subplots(2, 1)
ax[0].scatter(...)
ax[1].scatter(...)
plt.tight_layout()
.
.
.
plt.show()

before

after

reference:

https://matplotlib.org/users/tight_layout_guide.html

How to reference Microsoft.Office.Interop.Excel dll?

You can also try installing it in Visual Studio via Package Manager.

Run Install-Package Microsoft.Office.Interop.Excel in the Package Console. This will automatically add it as a project reference.

Use is like this:

Using Excel=Microsoft.Office.Interop.Excel;

How to add Certificate Authority file in CentOS 7

QUICK HELP 1: To add a certificate in the simple PEM or DER file formats to the list of CAs trusted on the system:

add it as a new file to directory /etc/pki/ca-trust/source/anchors/
run update-ca-trust extract

QUICK HELP 2: If your certificate is in the extended BEGIN TRUSTED file format (which may contain distrust/blacklist trust flags, or trust flags for usages other than TLS) then:

add it as a new file to directory /etc/pki/ca-trust/source/
run update-ca-trust extract

More detail infomation see man update-ca-trust

How to access Winform textbox control from another class?

I was also facing the same problem where I was not able to appendText to richTextBox of Form class. So I created a method called update, where I used to pass a message from Class1.

class: Form1.cs

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            _Form1 = this;
        }
        public static Form1 _Form1;

        public void update(string message)
        {
            textBox1.Text = message;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Class1 sample = new Class1();            
        }
    }

class: Class1.cs

public class Class1
    {        
        public Class1()
        {
            Form1._Form1.update("change text");
        }        
    }

jQuery: using a variable as a selector

You're thinking too complicated. It's actually just $('#'+openaddress).

How can I loop over entries in JSON?

Try this :

import urllib, urllib2, json
url = 'http://openligadb-json.heroku.com/api/teams_by_league_saison?league_saison=2012&league_shortcut=bl1'
request = urllib2.Request(url)
request.add_header('User-Agent','Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)')
request.add_header('Content-Type','application/json')
response = urllib2.urlopen(request)
json_object = json.load(response)
#print json_object['results']
if json_object['team'] == []:
    print 'No Data!'
else:
    for rows in json_object['team']:
        print 'Team ID:' + rows['team_id']
        print 'Team Name:' + rows['team_name']
        print 'Team URL:' + rows['team_icon_url']

3-dimensional array in numpy

You have a truncated array representation. Let's look at a full example:

>>> a = np.zeros((2, 3, 4))
>>> a
array([[[ 0.,  0.,  0.,  0.],
        [ 0.,  0.,  0.,  0.],
        [ 0.,  0.,  0.,  0.]],

       [[ 0.,  0.,  0.,  0.],
        [ 0.,  0.,  0.,  0.],
        [ 0.,  0.,  0.,  0.]]])

Arrays in NumPy are printed as the word array followed by structure, similar to embedded Python lists. Let's create a similar list:

>>> l = [[[ 0.,  0.,  0.,  0.],
          [ 0.,  0.,  0.,  0.],
          [ 0.,  0.,  0.,  0.]],

          [[ 0.,  0.,  0.,  0.],
          [ 0.,  0.,  0.,  0.],
          [ 0.,  0.,  0.,  0.]]]

>>> l
[[[0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0]], 
 [[0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0], [0.0, 0.0, 0.0, 0.0]]]

The first level of this compound list l has exactly 2 elements, just as the first dimension of the array a (# of rows). Each of these elements is itself a list with 3 elements, which is equal to the second dimension of a (# of columns). Finally, the most nested lists have 4 elements each, same as the third dimension of a (depth/# of colors).

So you've got exactly the same structure (in terms of dimensions) as in Matlab, just printed in another way.

Some caveats:

Matlab stores data column by column ("Fortran order"), while NumPy by default stores them row by row ("C order"). This doesn't affect indexing, but may affect performance. For example, in Matlab efficient loop will be over columns (e.g. for n = 1:10 a(:, n) end), while in NumPy it's preferable to iterate over rows (e.g. for n in range(10): a[n, :] -- note n in the first position, not the last).
If you work with colored images in OpenCV, remember that:

2.1. It stores images in BGR format and not RGB, like most Python libraries do.

2.2. Most functions work on image coordinates (x, y), which are opposite to matrix coordinates (i, j).

Implementing a slider (SeekBar) in Android

How to implement a SeekBar

Add the SeekBar to your layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_margin="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <SeekBar
        android:id="@+id/seekBar"
        android:max="100"
        android:progress="50"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

Notes

max is the highest value that the seek bar can go to. The default is 100. The minimum is 0. The xml min value is only available from API 26, but you can just programmatically convert the 0-100 range to whatever you need for earlier versions.
progress is the initial position of the slider dot (called a "thumb").
For a vertical SeekBar use android:rotation="270".

Listen for changes in code

public class MainActivity extends AppCompatActivity {

    TextView tvProgressLabel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // set a change listener on the SeekBar
        SeekBar seekBar = findViewById(R.id.seekBar);
        seekBar.setOnSeekBarChangeListener(seekBarChangeListener);

        int progress = seekBar.getProgress();
        tvProgressLabel = findViewById(R.id.textView);
        tvProgressLabel.setText("Progress: " + progress);
    }

    SeekBar.OnSeekBarChangeListener seekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            // updated continuously as the user slides the thumb
            tvProgressLabel.setText("Progress: " + progress);
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
            // called when the user first touches the SeekBar
        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            // called after the user finishes moving the SeekBar
        }
    };
}

Notes

If you don't need to do any updates while the user is moving the seekbar, then you can just update the UI in onStopTrackingTouch.

SQL query for extracting year from a date

just pass the columnName as parameter of YEAR

SELECT YEAR(ASOFDATE) from PSASOFDATE;

another is to use DATE_FORMAT

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

SQLFiddle Demo

UPDATE 1

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

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

SQLFiddle Demo

LAST RESORT if all the queries fail

use SUBSTRING

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

SQLFiddle Demo

Using a dictionary to select function to execute

Often classes are used to enclose methods and following is the extension for answers above with default method in case the method is not found.

class P:

     def p1(self):
         print('Start')

     def p2(self):
         print('Help')

     def ps(self):
         print('Settings')

     def d(self):
         print('Default function')

     myDict = {
         "start": p1,
         "help": p2,
         "settings": ps
     }

     def call_it(self):
         name = 'start'
         f = lambda self, x : self.myDict.get(x, lambda x : self.d())(self)
         f(self, name)


 p = P()
 p.call_it()

SELECT using 'CASE' in SQL

Change to:

SELECT 
  CASE 
    WHEN FRUIT = 'A' THEN 'APPLE' 
    WHEN FRUIT = 'B' THEN 'BANANA'     
  END
FROM FRUIT_TABLE;

Casting a number to a string in TypeScript

Just utilize toString or toLocaleString I'd say. So:

var page_number:number = 3;
window.location.hash = page_number.toLocaleString();

These throw an error if page_number is null or undefined. If you don't want that you can choose the fix appropriate for your situation:

// Fix 1:
window.location.hash = (page_number || 1).toLocaleString();

// Fix 2a:
window.location.hash = !page_number ? "1" page_number.toLocaleString();

// Fix 2b (allows page_number to be zero):
window.location.hash = (page_number !== 0 && !page_number) ? "1" page_number.toLocaleString();

How do I get the application exit code from a Windows command line?

Use the built-in ERRORLEVEL Variable:

echo %ERRORLEVEL%

But beware if an application has defined an environment variable named ERRORLEVEL!

In which case do you use the JPA @JoinTable annotation?

It's also cleaner to use @JoinTable when an Entity could be the child in several parent/child relationships with different types of parents. To follow up with Behrang's example, imagine a Task can be the child of Project, Person, Department, Study, and Process.

Should the task table have 5 nullable foreign key fields? I think not...

How can I get CMake to find my alternative Boost installation?

There is a generic method to give CMake directions about where to find libraries.

When looking for a library, CMake looks first in the following variables:

CMAKE_LIBRARY_PATH and LD_LIBRARY_PATH for libraries
CMAKE_INCLUDE_PATH and INCLUDE_PATH for includes

If you declare your Boost files in one of the environment variables, CMake will find it. Example:

export CMAKE_LIBRARY_PATH="/stuff/lib.boost.1.52/lib:$CMAKE_LIBRARY_PATH"
export CMAKE_INCLUDE_PATH="/stuff/lib.boost.1.52/include:$CMAKE_INCLUDE_PATH"

If it's too cumbersome, you can also use a nice installing tool I wrote that will do everything for you: C++ version manager

How to get the PID of a process by giving the process name in Mac OS X ?

You can install pidof with Homebrew:

brew install pidof
pidof <process_name>

Getting URL hash location, and using it in jQuery

I'm using this to address the security implications noted in @CMS's answer.

// example 1: www.example.com/index.html#foo

// load correct subpage from URL hash if it exists
$(window).on('load', function () {
    var hash = window.location.hash;
    if (hash) {
        hash = hash.replace('#',''); // strip the # at the beginning of the string
        hash = hash.replace(/([^a-z0-9]+)/gi, '-'); // strip all non-alphanumeric characters
        hash = '#' + hash; // hash now equals #foo with example 1

        // do stuff with hash
        $( 'ul' + hash + ':first' ).show();
        // etc...
    }
});

How do I generate a random int number?

Modified answer from here.

If you have access to an Intel Secure Key compatible CPU, you can generate real random numbers and strings using these libraries: https://github.com/JebteK/RdRand and https://www.rdrand.com/

Just download the latest version from here, include Jebtek.RdRand and add a using statement for it. Then, all you need to do is this:

// Check to see if this is a compatible CPU
bool isAvailable = RdRandom.GeneratorAvailable();

// Generate 10 random characters
string key       = RdRandom.GenerateKey(10);

 // Generate 64 random characters, useful for API keys 
string apiKey    = RdRandom.GenerateAPIKey();

// Generate an array of 10 random bytes
byte[] b         = RdRandom.GenerateBytes(10);

// Generate a random unsigned int
uint i           = RdRandom.GenerateUnsignedInt();

If you don't have a compatible CPU to execute the code on, just use the RESTful services at rdrand.com. With the RdRandom wrapper library included in your project, you would just need to do this (you get 1000 free calls when you signup):

string ret = Randomizer.GenerateKey(<length>, "<key>");
uint ret   = Randomizer.GenerateUInt("<key>");
byte[] ret = Randomizer.GenerateBytes(<length>, "<key>");

What is the best (idiomatic) way to check the type of a Python variable?

built-in types in Python have built in names:

>>> s = "hallo"
>>> type(s) is str
True
>>> s = {}
>>> type(s) is dict
True

btw note the is operator. However, type checking (if you want to call it that) is usually done by wrapping a type-specific test in a try-except clause, as it's not so much the type of the variable that's important, but whether you can do a certain something with it or not.

How to check if a file exists from a url

You can use the function file_get_contents();

if(file_get_contents('https://example.com/example.txt')) {
    //File exists
}

Function to close the window in Tkinter

class App():
    def __init__(self):
        self.root = Tkinter.Tk()
        button = Tkinter.Button(self.root, text = 'root quit', command=self.quit)
        button.pack()
        self.root.mainloop()

    def quit(self):
        self.root.destroy()

app = App()

How to specify jdk path in eclipse.ini on windows 8 when path contains space

if you are using mac, proceed with following steps:

Move to following directory:
```
/sts-bundle/STS.app/Contents/Eclipse
```

Add the java home explicitly in STS.ini file:

-vm
/Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home/bin
-vmargs

Make sure not to add all the statements in single line

How to sort a List<Object> alphabetically using Object name field

if(listAxu.size() > 0){
     Collections.sort(listAxu, new Comparator<Situacao>(){
        @Override
        public int compare(Situacao lhs, Situacao rhs) {            
            return lhs.getDescricao().compareTo(rhs.getDescricao());
        }
    });
 }

Uses of Action delegate in C#

We use a lot of Action delegate functionality in tests. When we need to build some default object and later need to modify it. I made little example. To build default person (John Doe) object we use BuildPerson() function. Later we add Jane Doe too, but we modify her birthdate and name and height.

public class Program
{
        public static void Main(string[] args)
        {
            var person1 = BuildPerson();

            Console.WriteLine(person1.Firstname);
            Console.WriteLine(person1.Lastname);
            Console.WriteLine(person1.BirthDate);
            Console.WriteLine(person1.Height);

            var person2 = BuildPerson(p =>
            {
                p.Firstname = "Jane";
                p.BirthDate = DateTime.Today;
                p.Height = 1.76;
            });

            Console.WriteLine(person2.Firstname);
            Console.WriteLine(person2.Lastname);
            Console.WriteLine(person2.BirthDate);
            Console.WriteLine(person2.Height);

            Console.Read();
        }

        public static Person BuildPerson(Action<Person> overrideAction = null)
        {
            var person = new Person()
            {
                Firstname = "John",
                Lastname = "Doe",
                BirthDate = new DateTime(2012, 2, 2)
            };

            if (overrideAction != null)
                overrideAction(person);

            return person;
        }
    }

    public class Person
    {
        public string Firstname { get; set; }
        public string Lastname { get; set; }
        public DateTime BirthDate { get; set; }
        public double Height { get; set; }
    }

Strip double quotes from a string in .NET

c#: "\"", thus s.Replace("\"", "")

vb/vbs/vb.net: "" thus s.Replace("""", "")

No 'Access-Control-Allow-Origin' header is present on the requested resource—when trying to get data from a REST API

Remove this:

credentials: 'include',

load Js file in HTML

I had the same problem, and found the answer. If you use node.js with express, you need to give it its own function in order for the js file to be reached. For example:

const script = path.join(__dirname, 'script.js');
const server = express().get('/', (req, res) => res.sendFile(script))

Finding duplicate values in MySQL

SELECT * 
FROM `dps` 
WHERE pid IN (SELECT pid FROM `dps` GROUP BY pid HAVING COUNT(pid)>1)

Regex allow a string to only contain numbers 0 - 9 and limit length to 45

You are almost there, all you need is start anchor (^) and end anchor ($):

^[0-9]{1,45}$

\d is short for the character class [0-9]. You can use that as:

^\d{1,45}$

The anchors force the pattern to match entire input, not just a part of it.

Your regex [0-9]{1,45} looks for 1 to 45 digits, so string like foo1 also get matched as it contains 1.

^[0-9]{1,45} looks for 1 to 45 digits but these digits must be at the beginning of the input. It matches 123 but also 123foo

[0-9]{1,45}$ looks for 1 to 45 digits but these digits must be at the end of the input. It matches 123 but also foo123

^[0-9]{1,45}$ looks for 1 to 45 digits but these digits must be both at the start and at the end of the input, effectively it should be entire input.

How do I configure modprobe to find my module?

I think the key is to copy the module to the standard paths.

Once that is done, modprobe only accepts the module name, so leave off the path and ".ko" extension.

File.separator vs FileSystem.getSeparator() vs System.getProperty("file.separator")?

System.getProperties() can be overridden by calls to System.setProperty(String key, String value) or with command line parameters -Dfile.separator=/

File.separator gets the separator for the default filesystem.

FileSystems.getDefault() gets you the default filesystem.

FileSystem.getSeparator() gets you the separator character for the filesystem. Note that as an instance method you can use this to pass different filesystems to your code other than the default, in cases where you need your code to operate on multiple filesystems in the one JVM.

How to read the post request parameters using JavaScript

One option is to set a cookie in PHP.

For example: a cookie named invalid with the value of $invalid expiring in 1 day:

setcookie('invalid', $invalid, time() + 60 * 60 * 24);

Then read it back out in JS (using the JS Cookie plugin):

var invalid = Cookies.get('invalid');

if(invalid !== undefined) {
    Cookies.remove('invalid');
}

You can now access the value from the invalid variable in JavaScript.

Jackson how to transform JsonNode to ArrayNode without casting?

In Java 8 you can do it like this:

import java.util.*;
import java.util.stream.*;

List<JsonNode> datasets = StreamSupport
    .stream(datasets.get("datasets").spliterator(), false)
    .collect(Collectors.toList())

How do I encrypt and decrypt a string in python?

Encrypt Data

First, we need to install the cryptography library:

pip3 install cryptography

From the cryptography library, we need to import Fernet and start generating a key - this key is required for symmetric encryption/decryption.
To generate a key, we call the generate_key() method.
- We only need to execute the above method once to generate a key.
You need to keep this key in a safe place. If you lose the key, you won't be able to decrypt the data that was encrypted with this key.
Once we have generated a key, we need to load the key with load_key()

Encrypt a Message

This is a three step process:

encode the message
initialize the Fernet class
pass the encoded message to encrypt() method

Below is a full working example of encrypting a message :

from cryptography.fernet import Fernet

def generate_key():
    """
    Generates a key and save it into a file
    """
    key = Fernet.generate_key()
    with open("secret.key", "wb") as key_file:
        key_file.write(key)

def load_key():
    """
    Load the previously generated key
    """
    return open("secret.key", "rb").read()

def encrypt_message(message):
    """
    Encrypts a message
    """
    key = load_key()
    encoded_message = message.encode()
    f = Fernet(key)
    encrypted_message = f.encrypt(encoded_message)

    print(encrypted_message)

if __name__ == "__main__":
    # generate_key() # execute only once 
    encrypt_message("Hello stackoverflow!")

output:

b'gAAAAABgLX7Zj-kn-We2BI_c9NQhEtfJEnHUVhVqtiqjkDi5dgJafj-_8QUDyeNS2zsJTdBWg6SntRJOjOM1U5mIxxsGny7IEGqpVVdHwheTnwzSBlgpb80='

Decrypt Data

To decrypt the message, we just call the decrypt() method from the Fernet library. Remember, we also need to load the key as well, because the key is needed to decrypt the message.

from cryptography.fernet import Fernet

def load_key():
    """
    Load the previously generated key
    """
    return open("secret.key", "rb").read()

def decrypt_message(encrypted_message):
    """
    Decrypts an encrypted message
    """
    key = load_key()
    f = Fernet(key)
    decrypted_message = f.decrypt(encrypted_message)

    print(decrypted_message.decode())

if __name__ == "__main__":
    decrypt_message(b'gAAAAABgLX7Zj-kn-We2BI_c9NQhEtfJEnHUVhVqtiqjkDi5dgJafj-_8QUDyeNS2zsJTdBWg6SntRJOjOM1U5mIxxsGny7IEGqpVVdHwheTnwzSBlgpb80=')

output:

Hello stackoverflow!

Your password is in the secret.key in a form similar to the password below:

B8wtXqwBA_zb2Iaz5pW8CIQIwGSYSFoBiLsVz-vTqzw=

Check if date is in the past Javascript

To make the answer more re-usable for things other than just the datepicker change function you can create a prototype to handle this for you.

// safety check to see if the prototype name is already defined
Function.prototype.method = function (name, func) {
    if (!this.prototype[name]) {
        this.prototype[name] = func;
        return this;
    }
};
Date.method('inPast', function () {
    return this < new Date($.now());// the $.now() requires jQuery
});

// including this prototype as using in example
Date.method('addDays', function (days) {
    var date = new Date(this);
    date.setDate(date.getDate() + (days));    
    return date;
});

If you dont like the safety check you can use the conventional way to define prototypes:

Date.prototype.inPast = function(){
    return this < new Date($.now());// the $.now() requires jQuery
}

Example Usage

var dt = new Date($.now());
var yesterday = dt.addDays(-1);
var tomorrow = dt.addDays(1);
console.log('Yesterday: ' + yesterday.inPast());
console.log('Tomorrow: ' + tomorrow.inPast());

`node-pre-gyp install --fallback-to-build` failed during MeanJS installation on OSX

i have tried upgrading node-gyp:

sudo npm install -g node-gyp

It worked for me.

I find the solution here, I hope it can help.

Should I put #! (shebang) in Python scripts, and what form should it take?

It's really just a matter of taste. Adding the shebang means people can invoke the script directly if they want (assuming it's marked as executable); omitting it just means python has to be invoked manually.

The end result of running the program isn't affected either way; it's just options of the means.

CSS get height of screen resolution

To get the screen resolution use should use Javascript instead of CSS: Use screen.height for height and screen.width for width.

Using Pairs or 2-tuples in Java

I will start from a general point of view about tuples in Java and finish with an implication for your concrete problem.

1) The way tuples are used in non-generic languages is avoided in Java because they are not type-safe (e.g. in Python: tuple = (4, 7.9, 'python')). If you still want to use something like a general purpose tuple (which is not recommended), you should use Object[] or List<Object> and cast the elements after a check with instanceof to assure type-safety.

Usually, tuples in a certain setting are always used the same way with containing the same structure. In Java, you have to define this structure explicitly in a class to provide well-defined, type-safe values and methods. This seems annoying and unnecessairy at first but prevents errors already at compile-time.

2) If you need a tuple containing the same (super-)classes Foo, use Foo[], List<Foo>, or List<? extends Foo> (or the lists's immutable counterparts). Since a tuple is not of a defined length, this solution is equivalent.

3) In your case, you seem to need a Pair (i.e. a tuple of well-defined length 2). This renders maerics's answer or one of the supplementary answers the most efficient since you can reuse the code in the future.

Mysql SELECT CASE WHEN something then return field

You are mixing the 2 different CASE syntaxes inappropriately.

Use this style (Searched)

  CASE  
  WHEN u.nnmu ='0' THEN mu.naziv_mesta
  WHEN u.nnmu ='1' THEN m.naziv_mesta
 ELSE 'GRESKA'
 END as mesto_utovara,

Or this style (Simple)

  CASE u.nnmu 
  WHEN '0' THEN mu.naziv_mesta
  WHEN '1' THEN m.naziv_mesta
 ELSE 'GRESKA'
 END as mesto_utovara,

Not This (Simple but with boolean search predicates)

  CASE u.nnmu 
  WHEN u.nnmu ='0' THEN mu.naziv_mesta
  WHEN u.nnmu ='1' THEN m.naziv_mesta
 ELSE 'GRESKA'
 END as mesto_utovara,

In MySQL this will end up testing whether u.nnmu is equal to the value of the boolean expression u.nnmu ='0' itself. Regardless of whether u.nnmu is 1 or 0 the result of the case expression itself will be 1

For example if nmu = '0' then (nnmu ='0') evaluates as true (1) and (nnmu ='1') evaluates as false (0). Substituting these into the case expression gives

 SELECT CASE  '0'
  WHEN 1 THEN '0'
  WHEN 0 THEN '1'
 ELSE 'GRESKA'
 END as mesto_utovara

if nmu = '1' then (nnmu ='0') evaluates as false (0) and (nnmu ='1') evaluates as true (1). Substituting these into the case expression gives

 SELECT CASE  '1'
  WHEN 0 THEN '0'
  WHEN 1 THEN '1'
 ELSE 'GRESKA'
 END as mesto_utovara

AngularJS- Login and Authentication in each route and controller

My solution breaks down in 3 parts: the state of the user is stored in a service, in the run method you watch when the route changes and you check if the user is allowed to access the requested page, in your main controller you watch if the state of the user change.

app.run(['$rootScope', '$location', 'Auth', function ($rootScope, $location, Auth) {
    $rootScope.$on('$routeChangeStart', function (event) {

        if (!Auth.isLoggedIn()) {
            console.log('DENY');
            event.preventDefault();
            $location.path('/login');
        }
        else {
            console.log('ALLOW');
            $location.path('/home');
        }
    });
}]);

You should create a service (I will name it Auth) which will handle the user object and have a method to know if the user is logged or not.

service:

 .factory('Auth', function(){
var user;

return{
    setUser : function(aUser){
        user = aUser;
    },
    isLoggedIn : function(){
        return(user)? user : false;
    }
  }
})

From your app.run, you should listen the $routeChangeStart event. When the route will change, it will check if the user is logged (the isLoggedIn method should handle it). It won't load the requested route if the user is not logged and it will redirect the user to the right page (in your case login).

The loginController should be used in your login page to handle login. It should just interract with the Auth service and set the user as logged or not.

loginController:

.controller('loginCtrl', [ '$scope', 'Auth', function ($scope, Auth) {
  //submit
  $scope.login = function () {
    // Ask to the server, do your job and THEN set the user

    Auth.setUser(user); //Update the state of the user in the app
  };
}])

From your main controller, you could listen if the user state change and react with a redirection.

.controller('mainCtrl', ['$scope', 'Auth', '$location', function ($scope, Auth, $location) {

  $scope.$watch(Auth.isLoggedIn, function (value, oldValue) {

    if(!value && oldValue) {
      console.log("Disconnect");
      $location.path('/login');
    }

    if(value) {
      console.log("Connect");
      //Do something when the user is connected
    }

  }, true);

Find all matches in workbook using Excel VBA

Using the Range.Find method, as pointed out above, along with a loop for each worksheet in the workbook, is the fastest way to do this. The following, for example, locates the string "Question?" in each worksheet and replaces it with the string "Answered!".

Sub FindAndExecute()

Dim Sh As Worksheet
Dim Loc As Range

For Each Sh In ThisWorkbook.Worksheets
    With Sh.UsedRange
        Set Loc = .Cells.Find(What:="Question?")
        If Not Loc Is Nothing Then
            Do Until Loc Is Nothing
                Loc.Value = "Answered!"
                Set Loc = .FindNext(Loc)
            Loop
        End If
    End With
    Set Loc = Nothing
Next

End Sub

Adding sheets to end of workbook in Excel (normal method not working?)

mainWB.Sheets.Add(After:=Sheets(Sheets.Count)).Name = new_sheet_name

should probably be

mainWB.Sheets.Add(After:=mainWB.Sheets(mainWB.Sheets.Count)).Name = new_sheet_name

Draw horizontal rule in React Native

Creating a reusable Line component worked for me:

import React from 'react';
import { View } from 'react-native';

export default function Line() {
    return (
        <View style={{
            height: 1,
            backgroundColor: 'rgba(255, 255, 255 ,0.3)',
            alignSelf: 'stretch'
        }} />
    )
}

Now, Import and use Line anywhere:

<Line />

How to access site running apache server over lan without internet connection

nothing to be done for running your wamp sites to another computer. 1. first turn off the firewall. 2. Set Put Online in wamp by clcking in wamp icon at near to clock.

Finally run your browser in another computer and type http:\ip address or computer name e.g. http:\192.168.1.100

Setting Margin Properties in code

Depends on the situation, you can also try using padding property here...

MyControl.Margin=new Padding(0,0,0,0);

Plot multiple lines (data series) each with unique color in R

If your data is in wide format matplot is made for this and often forgotten about:

 dat <- matrix(runif(40,1,20),ncol=4) # make data
 matplot(dat, type = c("b"),pch=1,col = 1:4) #plot
 legend("topleft", legend = 1:4, col=1:4, pch=1) # optional legend

There is also the added bonus for those unfamiliar with things like ggplot that most of the plotting paramters such as pch etc. are the same using matplot() as plot(). enter image description here

favicon.png vs favicon.ico - why should I use PNG instead of ICO?

An ico can be a png.

More precisely, you can store one or more png inside this minimal container format, instead of the usual bitmap+alpha that everyone strongly associates with ico.

Support is old, appearing in Windows Vista (2007) and is well supported by browsers, though not necessarily by icon editing software.

Any valid png (whole including header) can be prepended by a 6 byte ico header and 16 byte image directory.
GIMP has native support. Simply export as ico and tick "Compressed (PNG)".

How to disable "prevent this page from creating additional dialogs"?

You can't. It's a browser feature there to prevent sites from showing hundreds of alerts to prevent you from leaving.

You can, however, look into modal popups like jQuery UI Dialog. These are javascript alert boxes that show a custom dialog. They don't use the default alert() function and therefore, bypass the issue you're running into completely.

I've found that an apps that has a lot of message boxes and confirms has a much better user experience if you use custom dialogs instead of the default alerts and confirms.

Using multiple arguments for string formatting in Python (e.g., '%s ... %s')

On a tuple/mapping object for multiple argument `format`

The following is excerpt from the documentation:

Given format % values, % conversion specifications in format are replaced with zero or more elements of values. The effect is similar to the using sprintf() in the C language.

If format requires a single argument, values may be a single non-tuple object. Otherwise, values must be a tuple with exactly the number of items specified by the format string, or a single mapping object (for example, a dictionary).

References

docs.python.org/library/stdtypes - string formatting

On `str.format` instead of `%`

A newer alternative to % operator is to use str.format. Here's an excerpt from the documentation:

str.format(*args, **kwargs)

Perform a string formatting operation. The string on which this method is called can contain literal text or replacement fields delimited by braces {}. Each replacement field contains either the numeric index of a positional argument, or the name of a keyword argument. Returns a copy of the string where each replacement field is replaced with the string value of the corresponding argument.

This method is the new standard in Python 3.0, and should be preferred to % formatting.

References

docs.python.org/library/stdtypes - str.format - syntax

Examples

Here are some usage examples:

>>> '%s for %s' % ("tit", "tat")
tit for tat

>>> '{} and {}'.format("chicken", "waffles")
chicken and waffles

>>> '%(last)s, %(first)s %(last)s' % {'first': "James", 'last': "Bond"}
Bond, James Bond

>>> '{last}, {first} {last}'.format(first="James", last="Bond")
Bond, James Bond

Check if something is (not) in a list in Python

The bug is probably somewhere else in your code, because it should work fine:

>>> 3 not in [2, 3, 4]
False
>>> 3 not in [4, 5, 6]
True

Or with tuples:

>>> (2, 3) not in [(2, 3), (5, 6), (9, 1)]
False
>>> (2, 3) not in [(2, 7), (7, 3), "hi"]
True

jquery $(window).width() and $(window).height() return different values when viewport has not been resized

Note that if the problem is being caused by appearing scrollbars, putting

body {
  overflow: hidden;
}

in your CSS might be an easy fix (if you don't need the page to scroll).

How to change the data type of a column without dropping the column with query?

ALTER TABLE yourtable MODIFY COLUMN yourcolumn datatype

How do I create executable Java program?

Take a look at launch4j

Django - filtering on foreign key properties

student_user = User.objects.get(id=user_id)
available_subjects = Subject.objects.exclude(subject_grade__student__user=student_user) # My ans
enrolled_subjects = SubjectGrade.objects.filter(student__user=student_user)
context.update({'available_subjects': available_subjects, 'student_user': student_user, 
                'request':request, 'enrolled_subjects': enrolled_subjects})

In my application above, i assume that once a student is enrolled, a subject SubjectGrade instance will be created that contains the subject enrolled and the student himself/herself.

Subject and Student User model is a Foreign Key to the SubjectGrade Model.

In "available_subjects", i excluded all the subjects that are already enrolled by the current student_user by checking all subjectgrade instance that has "student" attribute as the current student_user

PS. Apologies in Advance if you can't still understand because of my explanation. This is the best explanation i Can Provide. Thank you so much

Xamarin 2.0 vs Appcelerator Titanium vs PhoneGap

I haven't worked much with Appcelerator Titanium, but I'll put my understanding of it at the end.

I can speak a bit more to the differences between PhoneGap and Xamarin, as I work with these two 5 (or more) days a week.

If you are already familiar with C# and JavaScript, then the question I guess is, does the business logic lie in an area more suited to JavaScript or C#?

PhoneGap

PhoneGap is designed to allow you to write your applications using JavaScript and HTML, and much of the functionality that they do provide is designed to mimic the current proposed specifications for the functionality that will eventually be available with HTML5. The big benefit of PhoneGap in my opinion is that since you are doing the UI with HTML, it can easily be ported between platforms. The downside is, because you are porting the same UI between platforms, it won't feel quite as at home in any of them. Meaning that, without further tweaking, you can't have an application that feels fully at home in iOS and Android, meaning that it has the iOS and Android styling. The majority of your logic can be written using JavaScript, which means it too can be ported between platforms. If the current PhoneGap API does most of what you want, then it's pretty easy to get up and running. If however, there are things you need from the device that are not in the API, then you get into the fun of Plugin Development, which will be in the native device's development language of choice (with one caveat, but I'll get to that), which means you would likely need to get up to speed quickly in Objective-C, Java, etc. The good thing about this model, is you can usually adapt many different native libraries to serve your purpose, and many libraries already have PhoneGap Plugins. Although you might not have much experience with these languages, there will at least be a plethora of examples to work from.

Xamarin

Xamarin.iOS and Xamarin.Android (also known as MonoTouch and MonoDroid), are designed to allow you to have one library of business logic, and use this within your application, and hook it into your UI. Because it's based on .NET 4.5, you get some awesome lambda notations, LINQ, and a whole bunch of other C# awesomeness, which can make writing your business logic less painful. The downside here is that Xamarin expects that you want to make your applications truly feel native on the device, which means that you will likely end up rewriting your UI for each platform, before hooking it together with the business logic. I have heard about MvvmCross, which is designed to make this easier for you, but I haven't really had an opportunity to look into it yet. If you are familiar with the MVVM system in C#, you may want to have a look at this. When it comes to native libraries, MonoTouch becomes interesting. MonoTouch requires a Binding library to tell your C# code how to link into the underlying Objective-C and Java code. Some of these libraries will already have bindings, but if yours doesn't, creating one can be, interesting. Xamarin has made a tool called Objective Sharpie to help with this process, and for the most part, it will get you 95% of the way there. The remaining 5% will probably take 80% of your time attempting to bind a library.

Update

As noted in the comments below, Xamarin has released Xamarin Forms which is a cross platform abstraction around the platform specific UI components. Definitely worth the look.

PhoneGap / Xamarin Hybrid

Now because I said I would get to it, the caveat mentioned in PhoneGap above, is a Hybrid approach, where you can use PhoneGap for part, and Xamarin for part. I have quite a bit of experience with this, and I would caution you against it. Highly. The problem with this, is it is such a no mans' land that if you ever run into issues, almost no one will have come close to what you're doing, and will question what you're trying to do greatly. It is doable, but it's definitely not fun.

Appcelerator Titanium

As I mentioned before, I haven't worked much with Appcelerator Titanium, So for the differences between them, I will suggest you look at Comparing Titanium and Phonegap or Comparison between Corona, Phonegap, Titanium as it has a very thorough description of the differences. Basically, it appears that though they both use JavaScript, how that JavaScript is interpreted is slightly different. With Titanium, you will be writing your JavaScript to the Titanium SDK, whereas with PhoneGap, you will write your application using the PhoneGap API. As PhoneGap is very HTML5 and JavaScript standards compliant, you can use pretty much any JavaScript libraries you want, such as JQuery. With PhoneGap your user interface will be composed of HTML and CSS. With Titanium, you will benefit from their Cross-platform XML which appears to generate Native components. This means it will definitely have a better native look and feel.

How to make a <div> always full screen?

What I found the best elegant way is like the following, the most trick here is make the div's position: fixed.

_x000D_

.mask {_x000D_
    background-color: rgba(0, 0, 0, 0.5);_x000D_
    position: fixed;_x000D_
    top: 0;_x000D_
    left: 0;_x000D_
    right: 0;_x000D_
    bottom: 0;_x000D_
    margin: 0;_x000D_
    box-sizing: border-box;_x000D_
    width: 100%;_x000D_
    height: 100%;_x000D_
    object-fit: contain;_x000D_
}

_x000D_

<html>_x000D_
  <head>_x000D_
  <title>Test</title>_x000D_
  </head>_x000D_
  <body>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <h1>Whatever it takes</h1>_x000D_
    <div class="mask"></div>_x000D_
    </body>_x000D_
  </html>

_x000D_

Lombok annotations do not compile under Intellij idea

IDEA 2016.1:

Install lombok plugin
Settings -> Compiler -> Annotation Processors -> Enable annotation processing: checked (default configuration)
Settings -> Compiler -> Annotation Processors -> Annotation Processors add "lombok.launch.AnnotationProcessorHider$AnnotationProcessor"

Also if you are using maven add to maven-compiler-plugin configuration -> annotationProcessors -> annotationProcessor: lombok.launch.AnnotationProcessorHider$AnnotationProcessor

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>${maven.plugin.compiler.version}</version>
  <configuration>
    <compilerVersion>${java.version}</compilerVersion>
    <source>${java.version}</source>
    <target>${java.version}</target>
    <annotationProcessors>
      <annotationProcessor>lombok.launch.AnnotationProcessorHider$AnnotationProcessor</annotationProcessor>
    </annotationProcessors>
  </configuration>
</plugin>

Accessing localhost of PC from USB connected Android mobile device

I've read numerous forums and tried play apps but not found a solution until now.

My scenario I believe is similar to yours, but I will clarify to help others. I have a locally hosted website and web services to be used by my android application. I need to have this working on the road for demonstration with only my laptop and no network connection.

Note: Using my iPhone as a wifi hotspot and connecting both my pc and my android device worked, but the iPhone 4S connection is slow and dropped out regularly.

My solution is as follows:

Unplug network cables on PC and turn off wifi.
Turn off wifi on android device
Connect android to pc via USB
Turn on "USB Tethering" in the android menu. (Under networks->more...->Tethering and portable hotspot")
Get the IP of your computer that has been assigned by the USB tether cable. (open command prompt and type "ipconfig" then look for the IP that the USB network adapter has assigned)
Open a browser on the PC using the IP address found instead of localhost to test. i.e. http://192.168.1.1/myWebSite
Open a browser on the android and test it works

How to handle windows file upload using Selenium WebDriver?

Use AutoIt Script To Handle File Upload In Selenium Webdriver. It's working fine for the above scenario.

Runtime.getRuntime().exec("E:\\AutoIT\\FileUpload.exe");

Please use below link for further assistance: http://www.guru99.com/use-autoit-selenium.html

How to get 2 digit year w/ Javascript?

another version:

var yy = (new Date().getFullYear()+'').slice(-2);

How does the "final" keyword in Java work? (I can still modify an object.)

When you make it static final it should be initialized in a static initialization block

    private static final List foo;

    static {
        foo = new ArrayList();
    }

    public Test()
    {
//      foo = new ArrayList();
        foo.add("foo"); // Modification-1
    }

ScrollIntoView() causing the whole page to move

var el = document.querySelector("yourElement");
window.scroll({top: el.offsetTop, behavior: 'smooth'});

Determine direct shared object dependencies of a Linux binary?

You can use readelf to explore the ELF headers. readelf -d will list the direct dependencies as NEEDED sections.

 $ readelf -d elfbin

Dynamic section at offset 0xe30 contains 22 entries:
  Tag        Type                         Name/Value
 0x0000000000000001 (NEEDED)             Shared library: [libssl.so.1.0.0]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
 0x000000000000000c (INIT)               0x400520
 0x000000000000000d (FINI)               0x400758
 ...

Parsing JSON Object in Java

I'm assuming you want to store the interestKeys in a list.

Using the org.json library:

JSONObject obj = new JSONObject("{interests : [{interestKey:Dogs}, {interestKey:Cats}]}");

List<String> list = new ArrayList<String>();
JSONArray array = obj.getJSONArray("interests");
for(int i = 0 ; i < array.length() ; i++){
    list.add(array.getJSONObject(i).getString("interestKey"));
}

Checking for directory and file write permissions in .NET

Directory.GetAccessControl(path) does what you are asking for.

public static bool HasWritePermissionOnDir(string path)
{
    var writeAllow = false;
    var writeDeny = false;
    var accessControlList = Directory.GetAccessControl(path);
    if (accessControlList == null)
        return false;
    var accessRules = accessControlList.GetAccessRules(true, true, 
                                typeof(System.Security.Principal.SecurityIdentifier));
    if (accessRules ==null)
        return false;

    foreach (FileSystemAccessRule rule in accessRules)
    {
        if ((FileSystemRights.Write & rule.FileSystemRights) != FileSystemRights.Write) 
            continue;

        if (rule.AccessControlType == AccessControlType.Allow)
            writeAllow = true;
        else if (rule.AccessControlType == AccessControlType.Deny)
            writeDeny = true;
    }

    return writeAllow && !writeDeny;
}

(FileSystemRights.Write & rights) == FileSystemRights.Write is using something called "Flags" btw which if you don't know what it is you should really read up on :)

Inline instantiation of a constant List

You'll need to use a static readonly list instead. And if you want the list to be immutable then you might want to consider using ReadOnlyCollection<T> rather than List<T>.

private static readonly ReadOnlyCollection<string> _metrics =
    new ReadOnlyCollection<string>(new[]
        {
            SourceFile.LOC,
            SourceFile.MCCABE,
            SourceFile.NOM,
            SourceFile.NOA,
            SourceFile.FANOUT,
            SourceFile.FANIN,
            SourceFile.NOPAR,
            SourceFile.NDC,
            SourceFile.CALLS
        });

public static ReadOnlyCollection<string> Metrics
{
    get { return _metrics; }
}

Disable developer mode extensions pop up in Chrome

As of May 2015 Chrome beta/dev/canary on Windows (see lines 75-78) always display this warning.

I've just patched chrome.dll (dev channel, 32-bit) using hiew32 demo version: run it, switch to hex view (Enter key), search for ExtensionDeveloperModeWarning (F7) then press F6 to find the referring code, go to nearby INC EAX line, which is followed by RETN, press F3 to edit, type 90 instead of 40, which will be rendered as NOP (no-op), save (F9).
Simplified method found by @Gsx, which also works for 64-bit Chrome dev:
1. run hiew32 demo (in admin mode) and open Chrome.dll
2. switch to hex view (Enter key)
3. search for ExtensionDeveloperModeWarning (F7)
4. press F3 to edit and replace the first letter "E" with any other character
5. save (F9).
patch.BAT script

Of course this will last only until the next update so whoever needs it frequently might write an auto-patcher or a launcher that patches the dll in memory.

Difference between DOM parentNode and parentElement

there is one more difference, but only in internet explorer. It occurs when you mix HTML and SVG. if the parent is the 'other' of those two, then .parentNode gives the parent, while .parentElement gives undefined.

What's the difference between ASCII and Unicode?

ASCII and Unicode are two character encodings. Basically, they are standards on how to represent difference characters in binary so that they can be written, stored, transmitted, and read in digital media. The main difference between the two is in the way they encode the character and the number of bits that they use for each. ASCII originally used seven bits to encode each character. This was later increased to eight with Extended ASCII to address the apparent inadequacy of the original. In contrast, Unicode uses a variable bit encoding program where you can choose between 32, 16, and 8-bit encodings. Using more bits lets you use more characters at the expense of larger files while fewer bits give you a limited choice but you save a lot of space. Using fewer bits (i.e. UTF-8 or ASCII) would probably be best if you are encoding a large document in English.

One of the main reasons why Unicode was the problem arose from the many non-standard extended ASCII programs. Unless you are using the prevalent page, which is used by Microsoft and most other software companies, then you are likely to encounter problems with your characters appearing as boxes. Unicode virtually eliminates this problem as all the character code points were standardized.

Another major advantage of Unicode is that at its maximum it can accommodate a huge number of characters. Because of this, Unicode currently contains most written languages and still has room for even more. This includes typical left-to-right scripts like English and even right-to-left scripts like Arabic. Chinese, Japanese, and the many other variants are also represented within Unicode. So Unicode won’t be replaced anytime soon.

In order to maintain compatibility with the older ASCII, which was already in widespread use at the time, Unicode was designed in such a way that the first eight bits matched that of the most popular ASCII page. So if you open an ASCII encoded file with Unicode, you still get the correct characters encoded in the file. This facilitated the adoption of Unicode as it lessened the impact of adopting a new encoding standard for those who were already using ASCII.

Summary:

1.ASCII uses an 8-bit encoding while Unicode uses a variable bit encoding.
2.Unicode is standardized while ASCII isn’t.
3.Unicode represents most written languages in the world while ASCII does not.
4.ASCII has its equivalent within Unicode.

Taken From: http://www.differencebetween.net/technology/software-technology/difference-between-unicode-and-ascii/#ixzz4zEjnxPhs

How do I split a string by a multi-character delimiter in C#?

string s = "This is a sentence.";
string[] res = s.Split(new string[]{ " is " }, StringSplitOptions.None);

for(int i=0; i<res.length; i++)
    Console.Write(res[i]);

EDIT: The "is" is padded on both sides with spaces in the array in order to preserve the fact that you only want the word "is" removed from the sentence and the word "this" to remain intact.

Getting request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource

Basically, to make a cross domain AJAX requests, the requested server should allow the cross origin sharing of resources (CORS). You can read more about that from here: http://www.html5rocks.com/en/tutorials/cors/

In your scenario, you are setting the headers in the client which in fact needs to be set into http://localhost:8080/app server side code.

If you are using PHP Apache server, then you will need to add following in your .htaccess file:

Header set Access-Control-Allow-Origin "*"

Does :before not work on img elements?

Due to the nature of <img> being a replaced element, document styling doesn’t affected it.

To reference it anyway, <picture> provides an ideal, native wrapper that can have pseudo-elements attached to it, like so:

_x000D_

img:after, picture:after{_x000D_
    content:"\1F63B";_x000D_
    font-size:larger;_x000D_
    margin:-1em;_x000D_
}

_x000D_

<img src="//placekitten.com/110/80">_x000D_
_x000D_
<picture>_x000D_
    <img src="//placekitten.com/110/80">_x000D_
</picture>

_x000D_

Javascript change date into format of (dd/mm/yyyy)

Some JavaScript engines can parse that format directly, which makes the task pretty easy:

_x000D_

function convertDate(inputFormat) {_x000D_
  function pad(s) { return (s < 10) ? '0' + s : s; }_x000D_
  var d = new Date(inputFormat)_x000D_
  return [pad(d.getDate()), pad(d.getMonth()+1), d.getFullYear()].join('/')_x000D_
}_x000D_
_x000D_
console.log(convertDate('Mon Nov 19 13:29:40 2012')) // => "19/11/2012"

_x000D_

Difference between ${} and $() in Bash

$() means: "first evaluate this, and then evaluate the rest of the line".

Ex :
```
echo $(pwd)/myFile.txt
```
will be interpreted as
```
echo /my/path/myFile.txt
```
On the other hand ${} expands a variable.

Ex:
```
MY_VAR=toto
echo ${MY_VAR}/myFile.txt
```
will be interpreted as
```
echo toto/myFile.txt
```
Why can't I use it as bash$ while ((i=0;i<10;i++)); do echo $i; done

I'm afraid the answer is just that the bash syntax for while just isn't the same as the syntax for for.

How do I install cURL on cygwin?

Nobody said how to install apt-cyg

in cygwin

lynx -source rawgit.com/transcode-open/apt-cyg/master/apt-cyg > apt-cyg
install apt-cyg /bin

now you can

apt-cyg install curl

For more, see the official github repository of apt-cyg.

Most efficient solution for reading CLOB to String, and String to CLOB in Java?

What's wrong with:

clob.getSubString(1, (int) clob.length());

For example Oracle oracle.sql.CLOB performs getSubString() on internal char[] which defined in oracle.jdbc.driver.T4CConnection and just System.arraycopy() and next wrap to String... You never get faster reading than System.arraycopy().

UPDATE Get driver ojdbc6.jar, decompile CLOB implementation, and study which case could be faster based on the internals knowledge.

Visual Studio popup: "the operation could not be completed"

I ran into this same problem but deleting the .suo file did not help. The only way I could get the project to load was by deleting the "Your_Project_FileName.csproj.user" file.

I ran into this problem again a few months later but this time deleting the "Your_Project_FileName.csproj.user" file didn't help like it did last time. I finally managed to track it down to an IIS Express issue. I removed the site from my applicationhost.config and let Visual Studio recreate it, this allowed the project to finally be loaded.

If Else If In a Sql Server Function

No one seems to have picked that if (yes=no)>na or (no=na)>yes or (na=yes)>no, you get NULL as the result. Don't believe this is what you are after.

Here's also a more condensed form of the function, which works even if any of yes, no or na_ans is NULL.

USE [***]
GO
/****** Object:  UserDefinedFunction [dbo].[fnActionSq]    Script Date: 02/17/2011 10:21:47 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION [dbo].[fnTally] (@SchoolId nvarchar(50))
RETURNS nvarchar(3)
AS 
BEGIN
return (select (
       select top 1 Result from
       (select 'Yes' Result, yes_ans union all
        select 'No', no_ans union all
        select 'N/A', na_ans) [ ]
        order by yes_ans desc, Result desc)
       from dbo.qrc_maintally
       where school_id = @SchoolId)
End

load json into variable

code bit should read:

var my_json;
$.getJSON(my_url, function(json) {
  my_json = json;
});

gdb: "No symbol table is loaded"

You have to add extra parameter -g, which generates source level debug information. It will look like:

gcc -g prog.c

After that you can use gdb in common way.

Laravel Eloquent where field is X or null

You could merge two queries together:

$merged = $query_one->merge($query_two);

HTML "overlay" which allows clicks to fall through to elements behind it

In case anyone else is running in to the same problem, the only solution I could find that satisfied me was to have the canvas cover everything and then to raise the Z-index of all clickable elements. You can't draw on them, but at least they are clickable...

How to get a context in a recycler view adapter

You can use pub_image context (holder.pub_image.getContext()) :

@Override
public void onBindViewHolder(ViewHolder ViewHolder, int position) {

    holder.txtHeader.setText(mDataset.get(position).getPost_text());

    Picasso.with(holder.pub_image.getContext()).load("http://i.imgur.com/DvpvklR.png").into(holder.pub_image);


}

.includes() not working in Internet Explorer

Or just put this in a Javascript file and have a good day :)

String.prototype.includes = function (str) {
  var returnValue = false;

  if (this.indexOf(str) !== -1) {
    returnValue = true;
  }

  return returnValue;
}

Synchronous Requests in Node.js

You should take a look at library called async

and try to use async.series call for your problem.

CentOS 64 bit bad ELF interpreter

In general, when you get an error like this, just do

yum provides ld-linux.so.2

then you'll see something like:

glibc-2.20-5.fc21.i686 : The GNU libc libraries
Repo        : fedora
Matched from:
Provides    : ld-linux.so.2

and then you just run the following like BRPocock wrote (in case you were wondering what the logic was...):

yum install glibc.i686

jquery: get elements by class name and add css to each of them

You can try this

 $('div.easy_editor').css({'border-width':'9px', 'border-style':'solid', 'border-color':'red'});

The $('div.easy_editor') refers to a collection of all divs that have the class easy editor already. There is no need to use each() unless there was some function that you wanted to run on each. The css() method actually applies to all the divs you find.

Redirect output of mongo query to a csv file

Mongo's in-built export is working fine, unless you want to any data manipulation like format date, covert data types etc.

Following command works as charm.

    mongoexport -h localhost -d databse -c collection --type=csv 
    --fields erpNum,orderId,time,status 
    -q '{"time":{"$gt":1438275600000}, "status":{"$ne" :"Cancelled"}}' 
    --out report.csv

How do Python functions handle the types of the parameters that you pass in?

Python is strongly typed because every object has a type, every object knows its type, it's impossible to accidentally or deliberately use an object of a type "as if" it was an object of a different type, and all elementary operations on the object are delegated to its type.

This has nothing to do with names. A name in Python doesn't "have a type": if and when a name's defined, the name refers to an object, and the object does have a type (but that doesn't in fact force a type on the name: a name is a name).

A name in Python can perfectly well refer to different objects at different times (as in most programming languages, though not all) -- and there is no constraint on the name such that, if it has once referred to an object of type X, it's then forevermore constrained to refer only to other objects of type X. Constraints on names are not part of the concept of "strong typing", though some enthusiasts of static typing (where names do get constrained, and in a static, AKA compile-time, fashion, too) do misuse the term this way.

Comparing user-inputted characters in C

For a start, your answer variable should be of type char, not char*.

As for the if statement:

if (answer == ('Y' || 'y'))

This is first evaluating 'Y' || 'y' which, in Boolean logic (and for ASCII) is true since both of them are "true" (non-zero). In other words, you'd only get the if statement to fire if you'd somehow entered CTRLA (again, for ASCII, and where a true values equates to 1)^*a.

You could use the more correct:

if ((answer == 'Y') || (answer == 'y'))

but you really should be using:

if (toupper(answer) == 'Y')

since that's the more portable way to achieve the same end.

^*a You may be wondering why I'm putting in all sorts of conditionals for my statements. While the vast majority of C implementations use ASCII and certain known values, it's not necessarily mandated by the ISO standards. I know for a fact that at least one compiler still uses EBCDIC so I don't like making unwarranted assumptions.

How do you copy a record in a SQL table but swap out the unique id of the new row?

Here is how I did it using ASP classic and couldn't quite get it to work with the answers above and I wanted to be able to copy a product in our system to a new product_id and needed it to be able to work even when we add in more columns to the table.

Cn.Execute("CREATE TEMPORARY TABLE temprow AS SELECT * FROM product WHERE product_id = '12345'")
Cn.Execute("UPDATE temprow SET product_id = '34567'")
Cn.Execute("INSERT INTO product SELECT * FROM temprow")
Cn.Execute("DELETE temprow")
Cn.Execute("DROP TABLE temprow")

How to get item's position in a list?

Use enumerate:

testlist = [1,2,3,5,3,1,2,1,6]
for position, item in enumerate(testlist):
    if item == 1:
        print position

How to use Scanner to accept only valid int as input

This should work:

import java.util.Scanner;

public class Test {
    public static void main(String... args) throws Throwable {
        Scanner kb = new Scanner(System.in);

        int num1;
        System.out.print("Enter number 1: ");
        while (true)
            try {
                num1 = Integer.parseInt(kb.nextLine());
                break;
            } catch (NumberFormatException nfe) {
                System.out.print("Try again: ");
            }

        int num2;
        do {
            System.out.print("Enter number 2: ");
            while (true)
                try {
                    num2 = Integer.parseInt(kb.nextLine());
                    break;
                } catch (NumberFormatException nfe) {
                    System.out.print("Try again: ");
                }
        } while (num2 < num1);

    }
}

How to custom switch button?

You can use Android Material Components.

build.gradle:

implementation 'com.google.android.material:material:1.0.0'

layout.xml:

<com.google.android.material.button.MaterialButtonToggleGroup
        android:id="@+id/toggleGroup"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:checkedButton="@id/btn_one_way"
        app:singleSelection="true">

    <Button
            style="@style/Widget.MaterialComponents.Button.OutlinedButton"
            android:id="@+id/btn_one_way"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="One way trip" />

    <Button
            style="@style/Widget.MaterialComponents.Button.OutlinedButton"
            android:id="@+id/btn_round"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="Round trip" />

</com.google.android.material.button.MaterialButtonToggleGroup>

Windows 10 SSH keys

If you have Windows 10 with the OpenSSH client you may be able to generate the key, but you will have trouble copying it to the target Linux box as the ssh-copy-id command is not part of the client toolset.

Having has this problem I wrote a small PowerShell function to address this, that you add to your profile.

function ssh-copy-id([string]$userAtMachine, [string]$port = 22) {   
    # Get the generated public key
    $key = "$ENV:USERPROFILE" + "/.ssh/id_rsa.pub"
    # Verify that it exists
    if (!(Test-Path "$key")) {
        # Alert user
        Write-Error "ERROR: '$key' does not exist!"            
    }
    else {  
        # Copy the public key across
        & cat "$key" | ssh $userAtMachine -p $port "umask 077; test -d .ssh || mkdir .ssh ; cat >> .ssh/authorized_keys || exit 1"      
    }
}

You can get the gist here

I have a brief write up about it here

How to define dimens.xml for every different screen size in android?

Use Scalable DP

Although making a different layout for different screen sizes is theoretically a good idea, it can get very difficult to accommodate for all screen dimensions, and pixel densities. Having over 20+ different dimens.xml files as suggested in the above answers, is not easy to manage at all.

How To Use:

To use sdp:

Include implementation 'com.intuit.sdp:sdp-android:1.0.5' in your build.gradle,

Replace any dp value such as 50dp with a @dimen/50_sdp like so:

<TextView
 android:layout_width="@dimen/_50sdp"
 android:layout_height="@dimen/_50sdp"
 android:text="Hello World!" />

How It Works:

sdp scales with the screen size because it is essentially a huge list of different dimens.xml for every possible dp value.

See It In Action:

Here it is on three devices with widely differing screen dimensions, and densities:

Note that the sdp size unit calculation includes some approximation due to some performance and usability constraints.

IE throws JavaScript Error: The value of the property 'googleMapsQuery' is null or undefined, not a Function object (works in other browsers)

I found the answer, and in spite of what I reported, it was NOT browser specific. The bug was in my function code, and would have occurred in any browser. It boils down to this. I had two lines in my code that were FireFox/FireBug specific. They used console.log. In IE, they threw an error, so I commented them out (or so I thought). I did a crappy job commenting them out, and broke the bracketing in my function.

Original Code (with console.log in it):

if (sxti.length <= 50) console.log('sxti=' + sxti);
if (sxph.length <= 50) console.log('sxph=' + sxph);

Broken Code (misplaced brackets inside comments):

if (sxti.length <= 50) { //console.log('sxti=' + sxti); }
if (sxph.length <= 50) { //console.log('sxph=' + sxph); }

Fixed Code (fixed brackets outside comments):

if (sxti.length <= 50) { }//console.log('sxti=' + sxti);
if (sxph.length <= 50) { }//console.log('sxph=' + sxph);

So, it was my own sloppy coding. The function really wasn't defined, because a syntax error kept it from being closed.

Oh well, live and learn. ;)

regex to match a single character that is anything but a space

The following should suffice:

[^ ]

If you want to expand that to anything but white-space (line breaks, tabs, spaces, hard spaces):

[^\s]

\S  # Note this is a CAPITAL 'S'!

Retrofit 2 - URL Query Parameter

If you specify @GET("foobar?a=5"), then any @Query("b") must be appended using &, producing something like foobar?a=5&b=7.

If you specify @GET("foobar"), then the first @Query must be appended using ?, producing something like foobar?b=7.

That's how Retrofit works.

When you specify @GET("foobar?"), Retrofit thinks you already gave some query parameter, and appends more query parameters using &.

Remove the ?, and you will get the desired result.

How to print a debug log?

A lesser known trick is that mod_php maps stderr to the Apache log. And, there is a stream for that, so file_put_contents('php://stderr', print_r($foo, TRUE)) will nicely dump the value of $foo into the Apache error log.

jQuery delete confirmation box

I used this:

<a href="url/to/delete.asp" onclick="return confirm(' you want to delete?');">Delete</a>

How to type a new line character in SQL Server Management Studio

In SSMS, you can't print new line with select, just using PRINT instead

DECLARE @text NVARCHAR(100)
SET @text = concat(N'This is line 1.', CHAR(10), N'This is line 2.')
PRINT @text

C# go to next item in list based on if statement in foreach

You should use:

continue;

How do you cache an image in Javascript

as @Pointy said you don't cache images with javascript, the browser does that. so this may be what you are asking for and may not be... but you can preload images using javascript. By putting all of the images you want to preload into an array and putting all of the images in that array into hidden img elements, you effectively preload (or cache) the images.

var images = [
'/path/to/image1.png',
'/path/to/image2.png'
];

$(images).each(function() {
var image = $('<img />').attr('src', this);
});

jquery change style of a div on click

you can use .css method of jquery..

reference css method

What is a monad?

A Monad is an Applicative (i.e. something that you can lift binary -- hence, "n-ary" -- functions to,⁽¹⁾ and inject pure values into⁽²⁾) Functor (i.e. something that you can map over,⁽³⁾ i.e. lift unary functions to⁽³⁾) with the added ability to flatten the nested datatype (with each of the three notions following its corresponding set of laws). In Haskell, this flattening operation is called join.

The general (generic, parametric) type of this "join" operation is:

join  ::  Monad m  =>  m (m a)  ->  m a

for any monad m (NB all ms in the type are the same!).

A specific m monad defines its specific version of join working for any value type a "carried" by the monadic values of type m a. Some specific types are:

join  ::  [[a]]           -> [a]         -- for lists, or nondeterministic values
join  ::  Maybe (Maybe a) -> Maybe a     -- for Maybe, or optional values
join  ::  IO    (IO    a) -> IO    a     -- for I/O-produced values

The join operation converts an m-computation producing an m-computation of a-type values into one combined m-computation of a-type values. This allows for combination of computation steps into one larger computation.

This computation steps-combining "bind" (>>=) operator simply uses fmap and join together, i.e.

(ma >>= k)  ==  join (fmap k ma)
{-
  ma        :: m a            -- `m`-computation which produces `a`-type values
  k         ::   a -> m b     --  create new `m`-computation from an `a`-type value
  fmap k ma :: m    ( m b )   -- `m`-computation of `m`-computation of `b`-type values
  (m >>= k) :: m        b     -- `m`-computation which produces `b`-type values
-}

Conversely, join can be defined via bind, join mma == join (fmap id mma) == mma >>= id where id ma = ma -- whichever is more convenient for a given type m.

For monads, both the do-notation and its equivalent bind-using code,

do { x <- mx ; y <- my ; return (f x y) }        --   x :: a   ,   mx :: m a
                                                 --   y :: b   ,   my :: m b
mx >>= (\x ->                                    -- nested
            my >>= (\y ->                        --  lambda
                         return (f x y) ))       --   functions

can be read as

first "do" mx, and when it's done, get its "result" as x and let me use it to "do" something else.

In a given do block, each of the values to the right of the binding arrow <- is of type m a for some type a and the same monad m throughout the do block.

return x is a neutral m-computation which just produces the pure value x it is given, such that binding any m-computation with return does not change that computation at all.

⁽¹⁾ with liftA2 :: Applicative m => (a -> b -> c) -> m a -> m b -> m c

⁽²⁾ with pure :: Applicative m => a -> m a

⁽³⁾ with fmap :: Functor m => (a -> b) -> m a -> m b

There's also the equivalent Monad methods,

liftM2 :: Monad m => (a -> b -> c) -> m a -> m b -> m c
return :: Monad m =>  a            -> m a
liftM  :: Monad m => (a -> b)      -> m a -> m b

Given a monad, the other definitions could be made as

pure   a       = return a
fmap   f ma    = do { a <- ma ;            return (f a)   }
liftA2 f ma mb = do { a <- ma ; b <- mb  ; return (f a b) }
(ma >>= k)     = do { a <- ma ; b <- k a ; return  b      }

Difference between Interceptor and Filter in Spring MVC

Filter: - A filter as the name suggests is a Java class executed by the servlet container for each incoming HTTP request and for each http response. This way, is possible to manage HTTP incoming requests before them reach the resource, such as a JSP page, a servlet or a simple static page; in the same way is possible to manage HTTP outbound response after resource execution.

Interceptor: - Spring Interceptors are similar to Servlet Filters but they acts in Spring Context so are many powerful to manage HTTP Request and Response but they can implement more sophisticated behavior because can access to all Spring context.

C# - How to get Program Files (x86) on Windows 64 bit

The function below will return the x86 Program Files directory in all of these three Windows configurations:

32 bit Windows
32 bit program running on 64 bit Windows
64 bit program running on 64 bit windows

static string ProgramFilesx86()
{
    if( 8 == IntPtr.Size 
        || (!String.IsNullOrEmpty(Environment.GetEnvironmentVariable("PROCESSOR_ARCHITEW6432"))))
    {
        return Environment.GetEnvironmentVariable("ProgramFiles(x86)");
    }

    return Environment.GetEnvironmentVariable("ProgramFiles");
}

PHP XML how to output nice format

This is a slight variation of the above theme but I'm putting here in case others hit this and cannot make sense of it ...as I did.

When using saveXML(), preserveWhiteSpace in the target DOMdocument does not apply to imported nodes (as at PHP 5.6).

Consider the following code:

$dom = new DOMDocument();                               //create a document
$dom->preserveWhiteSpace = false;                       //disable whitespace preservation
$dom->formatOutput = true;                              //pretty print output
$documentElement = $dom->createElement("Entry");        //create a node
$dom->appendChild ($documentElement);                   //append it 
$message = new DOMDocument();                           //create another document
$message->loadXML($messageXMLtext);                     //populate the new document from XML text
$node=$dom->importNode($message->documentElement,true); //import the new document content to a new node in the original document
$documentElement->appendChild($node);                   //append the new node to the document Element
$dom->saveXML($dom->documentElement);                   //print the original document

In this context, the $dom->saveXML(); statement will NOT pretty print the content imported from $message, but content originally in $dom will be pretty printed.

In order to achieve pretty printing for the entire $dom document, the line:

$message->preserveWhiteSpace = false;

must be included after the $message = new DOMDocument(); line - ie. the document/s from which the nodes are imported must also have preserveWhiteSpace = false.

Selenium and xpath: finding a div with a class/id and verifying text inside

To verify this:-

<div class="Caption">
  Model saved
</div>

Write this -

//div[contains(@class, 'Caption') and text()='Model saved']

And to verify this:-

<div id="alertLabel" class="gwt-HTML sfnStandardLeftMargin sfnStandardRightMargin sfnStandardTopMargin">
  Save to server successful
</div>

Write this -

//div[@id='alertLabel' and text()='Save to server successful']

How do you load custom UITableViewCells from Xib files?

Loading UITableViewCells from XIBs saves a lot of code, but usually results in horrible scrolling speed (actually, it's not the XIB but the excessive use of UIViews that cause this).

I suggest you take a look at this: Link reference

How to fill in form field, and submit, using javascript?

You can try something like this:

    <script type="text/javascript">
        function simulateLogin(userName)
        {
            var userNameField = document.getElementById("username");
            userNameField.value = userName;
            var goButton = document.getElementById("go");
            goButton.click();
        }

        simulateLogin("testUser");
</script>

Why is Dictionary preferred over Hashtable in C#?

Another important difference is that Hashtable is thread safe. Hashtable has built-in multiple reader/single writer (MR/SW) thread safety which means Hashtable allows ONE writer together with multiple readers without locking.

In the case of Dictionary there is no thread safety; if you need thread safety you must implement your own synchronization.

To elaborate further:

Hashtable provides some thread-safety through the Synchronized property, which returns a thread-safe wrapper around the collection. The wrapper works by locking the entire collection on every add or remove operation. Therefore, each thread that is attempting to access the collection must wait for its turn to take the one lock. This is not scalable and can cause significant performance degradation for large collections. Also, the design is not completely protected from race conditions.

The .NET Framework 2.0 collection classes like List<T>, Dictionary<TKey, TValue>, etc. do not provide any thread synchronization; user code must provide all synchronization when items are added or removed on multiple threads concurrently

If you need type safety as well thread safety, use concurrent collections classes in the .NET Framework. Further reading here.

An additional difference is that when we add the multiple entries in Dictionary, the order in which the entries are added is maintained. When we retrieve the items from Dictionary we will get the records in the same order we have inserted them. Whereas Hashtable doesn't preserve the insertion order.

How to create circular ProgressBar in android?

It's easy to create this yourself

In your layout include the following ProgressBar with a specific drawable (note you should get the width from dimensions instead). The max value is important here:

<ProgressBar
    android:id="@+id/progressBar"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:max="500"
    android:progress="0"
    android:progressDrawable="@drawable/circular" />

Now create the drawable in your resources with the following shape. Play with the radius (you can use innerRadius instead of innerRadiusRatio) and thickness values.

circular (Pre Lollipop OR API Level < 21)

   <shape
        android:innerRadiusRatio="2.3"
        android:shape="ring"
        android:thickness="3.8sp" >
        <solid android:color="@color/yourColor" />
   </shape>

circular ( >= Lollipop OR API Level >= 21)

    <shape
        android:useLevel="true"
        android:innerRadiusRatio="2.3"
        android:shape="ring"
        android:thickness="3.8sp" >
        <solid android:color="@color/yourColor" />
     </shape>

useLevel is "false" by default in API Level 21 (Lollipop) .

Start Animation

Next in your code use an ObjectAnimator to animate the progress field of the ProgessBar of your layout.

ProgressBar progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
ObjectAnimator animation = ObjectAnimator.ofInt(progressBar, "progress", 0, 500); // see this max value coming back here, we animate towards that value
animation.setDuration(5000); // in milliseconds
animation.setInterpolator(new DecelerateInterpolator());
animation.start();

Stop Animation

progressBar.clearAnimation();

P.S. unlike examples above, it give smooth animation.

How to install/start Postman native v4.10.3 on Ubuntu 16.04 LTS 64-bit?

don't forget to

chmod ~/.local/share/applications/postman.desktop +x

otherwise it won't show in the Unity Launcher

How do I POST urlencoded form data with $http without jQuery?

URL-encoding variables using only AngularJS services

With AngularJS 1.4 and up, two services can handle the process of url-encoding data for POST requests, eliminating the need to manipulate the data with transformRequest or using external dependencies like jQuery:

$httpParamSerializerJQLike - a serializer inspired by jQuery's .param() (recommended)
$httpParamSerializer - a serializer used by Angular itself for GET requests

Example usage

$http({
  url: 'some/api/endpoint',
  method: 'POST',
  data: $httpParamSerializerJQLike($scope.appForm.data), // Make sure to inject the service you choose to the controller
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded' // Note the appropriate header
  }
}).then(function(response) { /* do something here */ });

See a more verbose Plunker demo

How are `$httpParamSerializerJQLike` and `$httpParamSerializer` different

In general, it seems $httpParamSerializer uses less "traditional" url-encoding format than $httpParamSerializerJQLike when it comes to complex data structures.

For example (ignoring percent encoding of brackets):

• Encoding an array

{sites:['google', 'Facebook']} // Object with array property

sites[]=google&sites[]=facebook // Result with $httpParamSerializerJQLike

sites=google&sites=facebook // Result with $httpParamSerializer

• Encoding an object

{address: {city: 'LA', country: 'USA'}} // Object with object property

address[city]=LA&address[country]=USA // Result with $httpParamSerializerJQLike

address={"city": "LA", country: "USA"} // Result with $httpParamSerializer

How does Django's Meta class work?

Answers that claim Django model's Meta and metaclasses are "completely different" are misleading answers.

The construction of Django model class objects, that is to say the object that stands for the class definition itself (yes, classes are also objects), are indeed controlled by a metaclass called ModelBase, and you can see that code here.

And one of the things that ModelBase does is to create the _meta attribute on every Django model which contains validation machinery, field details, save logic and so forth. During this operation, the stuff that is specified in the model's inner Meta class is read and used within that process.

So, while yes, in a sense Meta and metaclasses are different 'things', within the mechanics of Django model construction they are intimately related; understanding how they work together will deepen your insight into both at once.

This might be a helpful source of information to better understand how Django models employ metaclasses.

https://code.djangoproject.com/wiki/DevModelCreation

And this might help too if you want to better understand how objects work in general.

https://docs.python.org/3/reference/datamodel.html

Default value in Go's method

No, there is no way to specify defaults. I believer this is done on purpose to enhance readability, at the cost of a little more time (and, hopefully, thought) on the writer's end.

I think the proper approach to having a "default" is to have a new function which supplies that default to the more generic function. Having this, your code becomes clearer on your intent. For example:

func SaySomething(say string) {
    // All the complicated bits involved in saying something
}

func SayHello() {
    SaySomething("Hello")
}

With very little effort, I made a function that does a common thing and reused the generic function. You can see this in many libraries, fmt.Println for example just adds a newline to what fmt.Print would otherwise do. When reading someone's code, however, it is clear what they intend to do by the function they call. With default values, I won't know what is supposed to be happening without also going to the function to reference what the default value actually is.

Programs & Examples On #Format conversion

Convert XML to JSON (and back) using Javascript

How to make an Android Spinner with initial text "Select One"?

getElementsByClassName not working

How to remove listview all items

Setting Django up to use MySQL

How to call an element in a numpy array?

How can I exclude directories from grep -R?

C read file line by line

How to round a numpy array?

CSS: Control space between bullet and <li>

PHP - Fatal error: Unsupported operand types

Pandas: Creating DataFrame from Series

How to restore the permissions of files and directories within git if they have been modified?

'Class' does not contain a definition for 'Method'

What is the purpose and uniqueness SHTML?

Partly cherry-picking a commit with Git

How to force Chrome's script debugger to reload javascript?

C++ STL Vectors: Get iterator from index?

Why do we check up to the square root of a prime number to determine if it is prime?

How do I create a datetime in Python from milliseconds?

How to find first element of array matching a boolean condition in JavaScript?

Delete files or folder recursively on Windows CMD

What is the purpose of using -pedantic in GCC/G++ compiler?

ngFor with index as value in attribute

Angular >= 2

Angular = 1

Best way to check if a Data Table has a null value in it

Why is this inline-block element pushed downward?

SQL Error: ORA-12899: value too large for column

Linux find and grep command together

Shortcut to create properties in Visual Studio?

How to remove specific elements in a numpy array

Maven: Failed to retrieve plugin descriptor error

How to capture Curl output to a file?

Using Spring 3 autowire in a standalone Java application

Set space between divs

Use 'class' or 'typename' for template parameters?

PHP replacing special characters like à->a, è->e

It says that TypeError: document.getElementById(...) is null

How to center the text in a JLabel?

Spring Boot application as a Service

php - get numeric index of associative array

Using the Underscore module with Node.js

Where does PHP store the error log? (php5, apache, fastcgi, cpanel)

Why does overflow:hidden not work in a <td>?

Examples

Fixed width columns

Fixed and fluid width columns

ASP.Net which user account running Web Service on IIS 7?

vertical-align: middle doesn't work

Find the index of a char in string?

How to use opencv in using Gradle?

Follow the below steps to add Open CV in your project as library.

Calculate business days

How do I configure IIS for URL Rewriting an AngularJS application in HTML5 mode?

Error:Unable to locate adb within SDK in Android Studio

How to create Haar Cascade (.xml file) to use in OpenCV?

.prop() vs .attr()

Rails 4 - passing variable to partial

Running command line silently with VbScript and getting output?

Special characters like @ and & in cURL POST data

How to add a border to a widget in Flutter?

What are the differences between "git commit" and "git push"?

Plot size and resolution with R markdown, knitr, pandoc, beamer

UnsatisfiedDependencyException: Error creating bean with name

Python, Matplotlib, subplot: How to set the axis range?

Find unused code

Returning a value even if no result

Understanding dict.copy() - shallow or deep?

How can I get the client's IP address in ASP.NET MVC?

What are the use cases for selecting CHAR over VARCHAR in SQL?

How to get parameters from the URL with JSP

String delimiter in string.split method

Change form size at runtime in C#

Are table names in MySQL case sensitive?

Get resultset from oracle stored procedure

How to declare strings in C

How can I easily convert DataReader to List<T>?

Detect if the device is iPhone X

On a tuple/mapping object for multiple argument `format`