Programs & Examples On #Mysqlpp

MySQL++ is a C++ wrapper for MySQL’s C API.

Java: Unresolved compilation problem

(rewritten 2015-07-28)

The default behavior of Eclipse when compiling code with errors in it, is to generate byte code throwing the exception you see, allowing the program to be run. This is possible as Eclipse uses its own built-in compiler, instead of javac from the JDK which Apache Maven uses, and which fails the compilation completely for errors. If you use Eclipse on a Maven project which you are also working with using the command line mvn command, this may happen.

The cure is to fix the errors and recompile, before running again.

The setting is marked with a red box in this screendump:

Eclipse Preferences under OS X

angularjs: allows only numbers to be typed into a text box

<input type="phone" numbers-only >

You can use this way if you want only numbers :)

here is the the demo click

How to get the employees with their managers

TRY THIS

SELECT E.ename,E.empno,ISNULL(E.ename,'NO MANAGER') AS MANAGER FROM emp e
INNER JOIN emp M
ON  M.empno=E.empno

Instaed of subquery use self join

Change values on matplotlib imshow() graph axis

I had a similar problem and google was sending me to this post. My solution was a bit different and less compact, but hopefully this can be useful to someone.

Showing your image with matplotlib.pyplot.imshow is generally a fast way to display 2D data. However this by default labels the axes with the pixel count. If the 2D data you are plotting corresponds to some uniform grid defined by arrays x and y, then you can use matplotlib.pyplot.xticks and matplotlib.pyplot.yticks to label the x and y axes using the values in those arrays. These will associate some labels, corresponding to the actual grid data, to the pixel counts on the axes. And doing this is much faster than using something like pcolor for example.

Here is an attempt at this with your data:

import matplotlib.pyplot as plt

# ... define 2D array hist as you did

plt.imshow(hist, cmap='Reds')
x = np.arange(80,122,2) # the grid to which your data corresponds
nx = x.shape[0]
no_labels = 7 # how many labels to see on axis x
step_x = int(nx / (no_labels - 1)) # step between consecutive labels
x_positions = np.arange(0,nx,step_x) # pixel count at label position
x_labels = x[::step_x] # labels you want to see
plt.xticks(x_positions, x_labels)
# in principle you can do the same for y, but it is not necessary in your case

How to split a string and assign it to variables

Two steps, for example,

package main

import (
    "fmt"
    "strings"
)

func main() {
    s := strings.Split("127.0.0.1:5432", ":")
    ip, port := s[0], s[1]
    fmt.Println(ip, port)
}

Output:

127.0.0.1 5432

One step, for example,

package main

import (
    "fmt"
    "net"
)

func main() {
    host, port, err := net.SplitHostPort("127.0.0.1:5432")
    fmt.Println(host, port, err)
}

Output:

127.0.0.1 5432 <nil>

Using two CSS classes on one element

Another option is to use Descendant selectors

HTML:

<div class="social">
<p class="first">burrito</p>
<p class="last">chimichanga</p>
</div>

Reference first one in CSS: .social .first { color: blue; }

Reference last one in CSS: .social .last { color: green; }

Jsfiddle: https://jsfiddle.net/covbtpaq/153/

Add element to a list In Scala

Use import scala.collection.mutable.MutableList or similar if you really need mutation.

import scala.collection.mutable.MutableList
val x = MutableList(1, 2, 3, 4, 5)
x += 6 // MutableList(1, 2, 3, 4, 5, 6)
x ++= MutableList(7, 8, 9) // MutableList(1, 2, 3, 4, 5, 6, 7, 8, 9)

how to read a long multiline string line by line in python

by splitting with newlines.

for line in wallop_of_a_string_with_many_lines.split('\n'):
  #do_something..

if you iterate over a string, you are iterating char by char in that string, not by line.

>>>string = 'abc'
>>>for line in string:
    print line

a
b
c

How to reset postgres' primary key sequence when it falls out of sync?

If you see this error when you are loading custom SQL data for initialization, another way to avoid this is:

Instead of writing:

INSERT INTO book (id, name, price) VALUES (1 , 'Alchemist' , 10),

Remove the id (primary key) from initial data

INSERT INTO book (name, price) VALUES ('Alchemist' , 10),

This keeps the Postgres sequence in sync !

Benefits of inline functions in C++?

Inline functions are faster because you don't need to push and pop things on/off the stack like parameters and the return address; however, it does make your binary slightly larger.

Does it make a significant difference? Not noticeably enough on modern hardware for most. But it can make a difference, which is enough for some people.

Marking something inline does not give you a guarantee that it will be inline. It's just a suggestion to the compiler. Sometimes it's not possible such as when you have a virtual function, or when there is recursion involved. And sometimes the compiler just chooses not to use it.

I could see a situation like this making a detectable difference:

inline int aplusb_pow2(int a, int b) {
  return (a + b)*(a + b) ;
}

for(int a = 0; a < 900000; ++a)
    for(int b = 0; b < 900000; ++b)
        aplusb_pow2(a, b);

Capture characters from standard input without waiting for enter to be pressed

That's not possible in a portable manner in pure C++, because it depends too much on the terminal used that may be connected with stdin (they are usually line buffered). You can, however use a library for that:

  1. conio available with Windows compilers. Use the _getch() function to give you a character without waiting for the Enter key. I'm not a frequent Windows developer, but I've seen my classmates just include <conio.h> and use it. See conio.h at Wikipedia. It lists getch(), which is declared deprecated in Visual C++.

  2. curses available for Linux. Compatible curses implementations are available for Windows too. It has also a getch() function. (try man getch to view its manpage). See Curses at Wikipedia.

I would recommend you to use curses if you aim for cross platform compatibility. That said, I'm sure there are functions that you can use to switch off line buffering (I believe that's called "raw mode", as opposed to "cooked mode" - look into man stty). Curses would handle that for you in a portable manner, if I'm not mistaken.

How does "make" app know default target to build if no target is specified?

GNU Make also allows you to specify the default make target using a special variable called .DEFAULT_GOAL. You can even unset this variable in the middle of the Makefile, causing the next target in the file to become the default target.

Ref: The Gnu Make manual - Special Variables

How to remove .html from URL?

To remove the .html extension from your urls, you can use the following code in root/htaccess :

RewriteEngine on


RewriteCond %{THE_REQUEST} /([^.]+)\.html [NC]
RewriteRule ^ /%1 [NC,L,R]

RewriteCond %{REQUEST_FILENAME}.html -f
RewriteRule ^ %{REQUEST_URI}.html [NC,L]

NOTE: If you want to remove any other extension, for example to remove the .php extension, just replace the html everywhere with php in the code above.

Is there an ignore command for git like there is for svn?

There is no special git ignore command.

Edit a .gitignore file located in the appropriate place within the working copy. You should then add this .gitignore and commit it. Everyone who clones that repo will than have those files ignored.

Note that only file names starting with / will be relative to the directory .gitignore resides in. Everything else will match files in whatever subdirectory.

You can also edit .git/info/exclude to ignore specific files just in that one working copy. The .git/info/exclude file will not be committed, and will thus only apply locally in this one working copy.

You can also set up a global file with patterns to ignore with git config --global core.excludesfile. This will locally apply to all git working copies on the same user's account.

Run git help gitignore and read the text for the details.

Credit card expiration dates - Inclusive or exclusive?

How do time zones factor in this analysis. Does a card expire in New York before California? Does it depend on the billing or shipping addresses?

Exception : AAPT2 error: check logs for details

You have a problem with a png file maybe, look here :

1 more Caused by: com.android.tools.aapt2.Aapt2Exception: AAPT2 error: check logs for details at com.android.builder.png.AaptProcess$NotifierProcessOutput.handleOutput(AaptProcess.java:454)

It can be corrupted image or jpeg image with png extension

Find specific string in a text file with VBS script

Try to change like this ..

firstStr = "<?xml version" 'my file always starts like this

Do until objInputFile.AtEndOfStream  

    strToAdd = "<tr><td><a href=" & chr(34) & "../../Logs/DD/Beginning_of_DD_TC" & CStr(index) & ".html" & chr(34) & ">Beginning_of_DD_TC" & CStr(index) & "</a></td></tr>"  

   substrToFind = "<tr><td><a href=" & chr(34) & "../Test case " & trim(cstr((index)))

   tmpStr = objInputFile.ReadLine

   If InStr(tmpStr, substrToFind) <= 0 Then
       If Instr(tmpStr, firstStr) > 0 Then
          text = tmpStr 'to avoid the first empty line
       Else
          text = text & vbCrLf & tmpStr
       End If
   Else
      text = text & vbCrLf & strToAdd & vbCrLf & tmpStr

   End If
   index = index + 1
Loop

how to use getSharedPreferences in android

//Set Preference
SharedPreferences myPrefs = getSharedPreferences("myPrefs", MODE_WORLD_READABLE);
SharedPreferences.Editor prefsEditor;  
prefsEditor = myPrefs.edit();  
//strVersionName->Any value to be stored  
prefsEditor.putString("STOREDVALUE", strVersionName);  
prefsEditor.commit();

//Get Preferenece  
SharedPreferences myPrefs;    
myPrefs = getSharedPreferences("myPrefs", MODE_WORLD_READABLE);  
String StoredValue=myPrefs.getString("STOREDVALUE", "");

Try this..

Use Awk to extract substring

You just want to set the field separator as . using the -F option and print the first field:

$ echo aaa0.bbb.ccc | awk -F'.' '{print $1}'
aaa0

Same thing but using cut:

$ echo aaa0.bbb.ccc | cut -d'.' -f1
aaa0

Or with sed:

$ echo aaa0.bbb.ccc | sed 's/[.].*//'
aaa0

Even grep:

$ echo aaa0.bbb.ccc | grep -o '^[^.]*'
aaa0

Get the data received in a Flask request

For URL query parameters, use request.args.

search = request.args.get("search")
page = request.args.get("page")

For posted form input, use request.form.

email = request.form.get('email')
password = request.form.get('password')

For JSON posted with content type application/json, use request.get_json().

data = request.get_json()

Environment variables for java installation

In Windows inorder to set

Step 1 : Right Click on MyComputer and click on properties .

Step 2 : Click on Advanced tab

alt text

Step 3: Click on Environment Variables

alt text

Step 4: Create a new class path for JAVA_HOME

alt text

Step 5: Enter the Variable name as JAVA_HOME and the value to your jdk bin path ie c:\Programfiles\Java\jdk-1.6\bin and

NOTE Make sure u start with .; in the Value so that it doesn't corrupt the other environment variables which is already set.

alt text

Step 6 : Follow the Above step and edit the Path in System Variables add the following ;c:\Programfiles\Java\jdk-1.6\bin in the value column.

Step 7 :Your are done setting up your environment variables for your Java , In order to test it go to command prompt and type

 java   

who will get a list of help doc

In order make sure whether compiler is setup Type in cmd

  javac

who will get a list related to javac

Hope this Helps !

Powershell: A positional parameter cannot be found that accepts argument "xxx"

In my case there was a corrupted character in one of the named params ("-StorageAccountName" for cmdlet "Get-AzureStorageKey") which showed as perfectly normal in my editor (SublimeText) but Windows Powershell couldn't parse it.

To get to the bottom of it, I moved the offending lines from the error message into another .ps1 file, ran that, and the error now showed a botched character at the beginning of my "-StorageAccountName" parameter.

Deleting the character (again which looks normal in the actual editor) and re-typing it fixes this issue.

How to "git show" a merge commit with combined diff output even when every changed file agrees with one of the parents?

in your case you just need to

git diff HEAD^ HEAD^2

or just hash for you commit:

git diff 0e1329e55^ 0e1329e55^2

Change directory in Node.js command prompt

.help will show you all the options. Do .exit in this case

illegal character in path

You seem to have the quote marks (") embedded in your string at the start and the end. These are not needed and are illegal characters in a path. How are you initializing the string with the path?

This can be seen from the debugger visualizer, as the string starts with "\" and ends with \"", it shows that the quotes are part of the string, when they shouldn't be.

You can do two thing - a regular escaped string (using \) or a verbatim string literal (that starts with a @):

  string str = "C:\\Program Files (x86)\\test software\\myapp\\demo.exe";

Or:

  string verbatim = @"C:\Program Files (x86)\test software\myapp\demo.exe";

Position Relative vs Absolute?

Another thing to note is that if you want a absolute element to be confined to a parent element then you need to set the parent element's position to relative. That will keep the child element contained within the parent element and it won't be "relative" to the entire window.

I wrote a blog post that gives a simple example that creates the following affect:

enter image description here

That has a green div that is absolutely positioned to the bottom of the parent yellow div.

1 http://blog.troygrosfield.com/2013/02/11/working-with-css-positions-creating-a-simple-progress-bar/

Changing MongoDB data store directory

I found a special case that causes symlinks to appear to fail:

I did a standard enterprise install of mongodb but changed the /var/lib/mongodb to a symlink as I wanted to use an XFS filesystem for my database folder and a third filesystem for the log folder.

$sudo systemctl start mongod (fails with a message no permission to write to mongodb.log).. but it succceded if I started with the same configuration file:

.. as the owner of the external drives (ziggy) I was able to start $mongod --config /etc/mongodb.conf --fork

I eventually discovered that .. the symlinks pointed to a different filesystem and the mongodb (user) did not have permission to browse the folder that the symlink referred. Both the symlinks and the folders the symlinks referred had expansive rights to the mongod user so it made no sense?

/var/log/mongodb was changed (from the std ent install) to a symlink AND I had checked before:

$ ll /var/log/mongodb lrwxrwxrwx 1 mongodb mongodb 38 Oct 28 21:58 /var/log/mongodb -> /media/ziggy/XFS_DB/mongodb/log/

$ ll -d /media/ziggy/Ext4DataBase/mongodb/log drwxrwxrwx 2 mongodb mongodb 4096 Nov 1 12:05 /media/ashley/XFS_DB/mongodb/log/

.. But so it seemed to make no sense.. of course user mongodb had rwx access to the link, the folder and to the file mongodb.log .. but it couldnt find it via the symlink because the BASE folder of the media couldnt be searched by mongodb.

SO.. I EVENTUALLY DID THIS: $ ll /media/ziggy/ . . drwx------ 5 ziggy ziggy 4096 Oct 28 21:49 XFS_DB/

and found the offending missing x permissions..

$chmod a+x /media/ziggy/XFS_DB solved the problem

Seems stupid in hindsight but no searches turned up anything useful.

Mongoose: Get full list of users

If you'd like to send the data to a view pass the following in.

    server.get('/usersList', function(req, res) {
        User.find({}, function(err, users) {
           res.render('/usersList', {users: users});
        });
    });

Inside your view you can loop through the data using the variable users

How do I determine the current operating system with Node.js

You are looking for the OS native module for Node.js:

v4: https://nodejs.org/dist/latest-v4.x/docs/api/os.html#os_os_platform

or v5 : https://nodejs.org/dist/latest-v5.x/docs/api/os.html#os_os_platform

os.platform()

Returns the operating system platform. Possible values are 'darwin', 'freebsd', 'linux', 'sunos' or 'win32'. Returns the value of process.platform.

How to read the last row with SQL Server

SELECT * from Employees where [Employee ID] = ALL (SELECT MAX([Employee ID]) from Employees)

how to get list of port which are in use on the server

Open up a command prompt then type...

netstat -a

How to align iframe always in the center

Try this:

#wrapper {
    text-align: center;
}

#wrapper iframe {
    display: inline-block;
}

How can I get a list of all classes within current module in Python?

I was able to get all I needed from the dir built in plus getattr.

# Works on pretty much everything, but be mindful that 
# you get lists of strings back

print dir(myproject)
print dir(myproject.mymodule)
print dir(myproject.mymodule.myfile)
print dir(myproject.mymodule.myfile.myclass)

# But, the string names can be resolved with getattr, (as seen below)

Though, it does come out looking like a hairball:

def list_supported_platforms():
    """
        List supported platforms (to match sys.platform)

        @Retirms:
            list str: platform names
    """
    return list(itertools.chain(
        *list(
            # Get the class's constant
            getattr(
                # Get the module's first class, which we wrote
                getattr(
                    # Get the module
                    getattr(platforms, item),
                    dir(
                        getattr(platforms, item)
                    )[0]
                ),
                'SYS_PLATFORMS'
            )
            # For each include in platforms/__init__.py 
            for item in dir(platforms)
            # Ignore magic, ourselves (index.py) and a base class.
            if not item.startswith('__') and item not in ['index', 'base']
        )
    ))

this.getClass().getClassLoader().getResource("...") and NullPointerException

When eclipse runs the test case it will look for the file in target/classes not src/test/resources. When the resource is saved eclipse should copy it from src/test/resources to target/classes if it has changed but if for some reason this has not happened then you will get this error. Check that the file exists in target/classes to see if this is the problem.

How to kill a nodejs process in Linux?

sudo netstat -lpn |grep :'3000'

3000 is port i was looking for, After first command you will have Process ID for that port

kill -9 1192

in my case 1192 was process Id of process running on 3000 PORT use -9 for Force kill the process

How to execute a shell script in PHP?

If you are having a small script that you need to run (I simply needed to copy a file), I found it much easier to call the commands on the PHP script by calling

exec("sudo cp /tmp/testfile1 /var/www/html/testfile2");

and enabling such transaction by editing (or rather adding) a permitting line to the sudoers by first calling sudo visudo and adding the following line to the very end of it

www-data ALL=(ALL) NOPASSWD:/bin/cp /tmp/testfile1 /var/www/html/testfile2

All I wanted to do was to copy a file and I have been having problems with doing so because of the root password problem, and as you mentioned I did NOT want to expose the system to have no password for all root transactions.

How to Truncate a string in PHP to the word closest to a certain number of characters?

This will return the first 200 characters of words:

preg_replace('/\s+?(\S+)?$/', '', substr($string, 0, 201));

Timer for Python game

import time

now = time.time()
future = now + 10
while time.time() < future:
    # do stuff
    pass

Alternatively, if you've already got your loop:

while True:
    if time.time() > future:
        break
    # do other stuff

This method works well with pygame, since it pretty much requires you to have a big main loop.

Cannot read property 'getContext' of null, using canvas

Write code in this manner ...

<canvas id="canvas" width="640" height="480"></canvas>
<script>
var Grid = function(width, height) {
    ...
    this.draw = function() {
    var canvas = document.getElementById("canvas");
    if(canvas.getContext) {
        var context = canvas.getContext("2d");
        for(var i = 0; i < width; i++) {
            for(var j = 0; j < height; j++) {
                if(isLive(i, j)) {
                    context.fillStyle = "lightblue";
                }
                else {
                    context.fillStyle = "yellowgreen";
                }
                context.fillRect(i*15, j*15, 14, 14);
                }
            }
        }
    }
 }

First write canvas tag and then write script tag. And write script tag in body.

Altering column size in SQL Server

alter table Employee alter column salary numeric(22,5)

Shell script to capture Process ID and kill it if exist

#!/bin/sh

#Find the Process ID for syncapp running instance

PID=`ps -ef | grep syncapp 'awk {print $2}'`

if [[ -z "$PID" ]] then
--->    Kill -9 PID
fi

Not sure if this helps, but 'kill' is not spelled correctly. It's capitalized.

Try 'kill' instead.

Understanding the main method of python

The Python approach to "main" is almost unique to the language(*).

The semantics are a bit subtle. The __name__ identifier is bound to the name of any module as it's being imported. However, when a file is being executed then __name__ is set to "__main__" (the literal string: __main__).

This is almost always used to separate the portion of code which should be executed from the portions of code which define functionality. So Python code often contains a line like:

#!/usr/bin/env python
from __future__ import print_function
import this, that, other, stuff
class SomeObject(object):
    pass

def some_function(*args,**kwargs):
    pass

if __name__ == '__main__':
    print("This only executes when %s is executed rather than imported" % __file__)

Using this convention one can have a file define classes and functions for use in other programs, and also include code to evaluate only when the file is called as a standalone script.

It's important to understand that all of the code above the if __name__ line is being executed, evaluated, in both cases. It's evaluated by the interpreter when the file is imported or when it's executed. If you put a print statement before the if __name__ line then it will print output every time any other code attempts to import that as a module. (Of course, this would be anti-social. Don't do that).

I, personally, like these semantics. It encourages programmers to separate functionality (definitions) from function (execution) and encourages re-use.

Ideally almost every Python module can do something useful if called from the command line. In many cases this is used for managing unit tests. If a particular file defines functionality which is only useful in the context of other components of a system then one can still use __name__ == "__main__" to isolate a block of code which calls a suite of unit tests that apply to this module.

(If you're not going to have any such functionality nor unit tests than it's best to ensure that the file mode is NOT executable).

Summary: if __name__ == '__main__': has two primary use cases:

  • Allow a module to provide functionality for import into other code while also providing useful semantics as a standalone script (a command line wrapper around the functionality)
  • Allow a module to define a suite of unit tests which are stored with (in the same file as) the code to be tested and which can be executed independently of the rest of the codebase.

It's fairly common to def main(*args) and have if __name__ == '__main__': simply call main(*sys.argv[1:]) if you want to define main in a manner that's similar to some other programming languages. If your .py file is primarily intended to be used as a module in other code then you might def test_module() and calling test_module() in your if __name__ == '__main__:' suite.

  • (Ruby also implements a similar feature if __file__ == $0).

"Invalid form control" only in Google Chrome

I had the error:

An invalid form control with name='telefono' is not focusable.

This was happening because I was not using the required field correctly, which enabled and disabled when clicking on a checkbok. The solution was to remove the required attribute whenever the checkbok was not marked and mark it as required when the checkbox was marked.

var telefono = document.getElementById("telefono");  
telefono.removeAttribute("required");

What's the foolproof way to tell which version(s) of .NET are installed on a production Windows Server?

The official way to detect .NET 3.0 is described here

http://msdn.microsoft.com/en-us/library/aa480198.aspx

Flawed, because it requires the caller to have registry access permissions.

MSDN also mentions a technique for detecting .NET 3.5 by checking the User Agent string:

http://msdn.microsoft.com/en-us/library/bb909885.aspx

I think Microsoft should have done a better job than this.

Laravel orderBy on a relationship

Try this solution.

$mainModelData = mainModel::where('column', $value)
    ->join('relationModal', 'main_table_name.relation_table_column', '=', 'relation_table.id')
    ->orderBy('relation_table.title', 'ASC')
    ->with(['relationModal' => function ($q) {
        $q->where('column', 'value');
    }])->get();

Example:

$user = User::where('city', 'kullu')
    ->join('salaries', 'users.id', '=', 'salaries.user_id')
    ->orderBy('salaries.amount', 'ASC')
    ->with(['salaries' => function ($q) {
        $q->where('amount', '>', '500000');
    }])->get();

You can change the column name in join() as per your database structure.

Abstract variables in Java?

Change the code to:

public abstract class clsAbstractTable {
  protected String TAG;
  public abstract void init();
}

public class clsContactGroups extends clsAbstractTable {
  public String doSomething() {
    return TAG + "<something else>";
  }
}

That way, all of the classes who inherit this class will have this variable. You can do 200 subclasses and still each one of them will have this variable.

Side note: do not use CAPS as variable name; common wisdom is that all caps identifiers refer to constants, i.e. non-changeable pieces of data.

Set Radiobuttonlist Selected from Codebehind

We can change the item by value, here is the trick:

radio1.ClearSelection();
radio1.Items.FindByValue("1").Selected = true;// 1 is the value of option2

Javascript Array Alert

If you want to see the array as an array, you can say

alert(JSON.stringify(aCustomers));

instead of all those document.writes.

http://jsfiddle.net/5b2eb/

However, if you want to display them cleanly, one per line, in your popup, do this:

alert(aCustomers.join("\n"));

http://jsfiddle.net/5b2eb/1/

Invalid date in safari

This will not work alert(new Date('2010-11-29')); safari have some weird/strict way of processing date format alert(new Date(String('2010-11-29'))); try like this.

(Or)

Using Moment js will solve the issue though, After ios 14 the safari gets even weird

Try this alert(moment(String("2015-12-31 00:00:00")));

Moment JS

Converting strings to floats in a DataFrame

You can try df.column_name = df.column_name.astype(float). As for the NaN values, you need to specify how they should be converted, but you can use the .fillna method to do it.

Example:

In [12]: df
Out[12]: 
     a    b
0  0.1  0.2
1  NaN  0.3
2  0.4  0.5

In [13]: df.a.values
Out[13]: array(['0.1', nan, '0.4'], dtype=object)

In [14]: df.a = df.a.astype(float).fillna(0.0)

In [15]: df
Out[15]: 
     a    b
0  0.1  0.2
1  0.0  0.3
2  0.4  0.5

In [16]: df.a.values
Out[16]: array([ 0.1,  0. ,  0.4])

I keep getting "Uncaught SyntaxError: Unexpected token o"

Another hints for Unexpected token errors. There are two major differences between javascript objects and json:

  1. json data must be always quoted with double quotes.
  2. keys must be quoted

Correct JSON

 {
    "english": "bag",
    "kana": "kaban",
    "kanji": "K"
}

Error JSON 1

 {
    'english': 'bag',
    'kana': 'kaban',
    'kanji': 'K'
 }

Error JSON 2

 {
    english: "bag",
    kana: "kaban",
    kanji: "K"
}

Remark

This is not a direct answer for that question. But it's an answer for Unexpected token errors. So it may be help others who stumple upon that question.

When to use static keyword before global variables?

Yes, use static

Always use static in .c files unless you need to reference the object from a different .c module.

Never use static in .h files, because you will create a different object every time it is included.

Calculate difference between 2 date / times in Oracle SQL

select (floor(((DATE2-DATE1)*24*60*60)/3600)|| ' : ' ||floor((((DATE2-DATE1)*24*60*60) -floor(((DATE2-DATE1)*24*60*60)/3600)*3600)/60)|| '  ' ) as time_difference from TABLE1 

Setting "checked" for a checkbox with jQuery

You can check a checkbox checked condition using JavaScript in different ways. You can see below.

  1. First method - $('.myCheckbox').prop('checked', true);

  2. Second method - $('.myCheckbox').attr('checked', true);

  3. Third method (for check condition if checkbox is checked or not) - $('.myCheckbox').is(':checked')

Android: Cancel Async Task

I had a similar problem - essentially I was getting a NPE in an async task after the user had destroyed the activity. After researching the problem on Stack Overflow, I adopted the following solution:

volatile boolean running;

public void onActivityCreated (Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    running=true;
    ...
    }


public void onDestroy() {
    super.onDestroy();

    running=false;
    ...
}

Then, I check "if running" periodically in my async code. I have stress tested this and I am now unable to "break" my activity. This works perfectly and has the advantage of being simpler than some of the solutions I have seen on SO.

Java: convert List<String> to a String

With java 1.8 stream can be used ,

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
List<String> list = Arrays.asList("Bill","Bob","Steve").
String str = list.stream().collect(Collectors.joining(" and "));

IE8 issue with Twitter Bootstrap 3

Use this solution

<!--[if lt IE 9]>
<script src="js/css3-mediaqueries.js"></script>
<link rel="stylesheet" type="text/css" href="css/bootstrap-ie7.css" />
<![endif]-->

This string <script src="js/css3-mediaqueries.js"></script> enable mediaqueries. This string <link rel="stylesheet" type="text/css" href="css/bootstrap-ie7.css" /> enable bootstrap fonts.

Tested on Bootstrap 3.3.5

Link to download mediaqieries.js. Link to download bootstrap-ie7.css

Simple mediaplayer play mp3 from file path?

I use this class for Audio play. If your audio location is raw folder.

Call method for play:

new AudioPlayer().play(mContext, getResources().getIdentifier(alphabetItemList.get(mPosition)
                        .getDetail().get(0).getAudio(),"raw", getPackageName()));

AudioPlayer.java class:

public class AudioPlayer {

    private MediaPlayer mMediaPlayer;

    public void stop() {
        if (mMediaPlayer != null) {
            mMediaPlayer.release();
            mMediaPlayer = null;
        }
    }
    // mothod for raw folder (R.raw.fileName)
    public void play(Context context, int rid){
        stop();

        mMediaPlayer = MediaPlayer.create(context, rid);
        mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mediaPlayer) {
                stop();
            }
        });

        mMediaPlayer.start();
    }

    // mothod for other folder 
    public void play(Context context, String name) {
        stop();

        //mMediaPlayer = MediaPlayer.create(c, rid);
        mMediaPlayer = MediaPlayer.create(context, Uri.parse("android.resource://"+ context.getPackageName()+"/your_file/"+name+".mp3"));
        mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mediaPlayer) {
                stop();
            }
        });

        mMediaPlayer.start();
    }

}

Calculate percentage Javascript

It seems working :

HTML :

 <input type='text' id="pointspossible"/>
<input type='text' id="pointsgiven" />
<input type='text' id="pointsperc" disabled/>

JavaScript :

    $(function(){

    $('#pointspossible').on('input', function() {
      calculate();
    });
    $('#pointsgiven').on('input', function() {
     calculate();
    });
    function calculate(){
        var pPos = parseInt($('#pointspossible').val()); 
        var pEarned = parseInt($('#pointsgiven').val());
        var perc="";
        if(isNaN(pPos) || isNaN(pEarned)){
            perc=" ";
           }else{
           perc = ((pEarned/pPos) * 100).toFixed(3);
           }

        $('#pointsperc').val(perc);
    }

});

Demo : http://jsfiddle.net/vikashvverma/1khs8sj7/1/

Mocking a function to raise an Exception to test an except block

Your mock is raising the exception just fine, but the error.resp.status value is missing. Rather than use return_value, just tell Mock that status is an attribute:

barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')

Additional keyword arguments to Mock() are set as attributes on the resulting object.

I put your foo and bar definitions in a my_tests module, added in the HttpError class so I could use it too, and your test then can be ran to success:

>>> from my_tests import foo, HttpError
>>> import mock
>>> with mock.patch('my_tests.bar') as barMock:
...     barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')
...     result = my_test.foo()
... 
404 - 
>>> result is None
True

You can even see the print '404 - %s' % error.message line run, but I think you wanted to use error.content there instead; that's the attribute HttpError() sets from the second argument, at any rate.

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

Update 2015-06

Based on antoinepairet's comment/example:

Using uib-collapse attribute provides animations: http://plnkr.co/edit/omyoOxYnCdWJP8ANmTc6?p=preview

<nav class="navbar navbar-default" role="navigation">
    <div class="navbar-header">

        <!-- note the ng-init and ng-click here: -->
        <button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
        </button>
        <a class="navbar-brand" href="#">Brand</a>
    </div>

    <div class="collapse navbar-collapse" uib-collapse="navCollapsed">
        <ul class="nav navbar-nav">
        ...
        </ul>
    </div>
</nav>

Ancient..

I see that the question is framed around BS2, but I thought I'd pitch in with a solution for Bootstrap 3 using ng-class solution based on suggestions in ui.bootstrap issue 394:

The only variation from the official bootstrap example is the addition of ng- attributes noted by comments, below:

<nav class="navbar navbar-default" role="navigation">
  <div class="navbar-header">

    <!-- note the ng-init and ng-click here: -->
    <button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
    <a class="navbar-brand" href="#">Brand</a>
  </div>

  <!-- note the ng-class here -->
  <div class="collapse navbar-collapse" ng-class="{'in':!navCollapsed}">

    <ul class="nav navbar-nav">
    ...

Here is an updated working example: http://plnkr.co/edit/OlCCnbGlYWeO7Nxwfj5G?p=preview (hat tip Lars)

This seems to works for me in simple use cases, but you'll note in the example that the second dropdown is cut off… good luck!

C: convert double to float, preserving decimal point precision

Floating point numbers are represented in scientific notation as a number of only seven significant digits multiplied by a larger number that represents the place of the decimal place. More information about it on Wikipedia:

http://en.wikipedia.org/wiki/Floating_point

Java String to Date object of the format "yyyy-mm-dd HH:mm:ss"

its work for me SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); sdf.format(new Date));

How to find specified name and its value in JSON-string from Java?

I agree that Google's Gson is clear and easy to use. But you should create a result class for getting an instance from JSON string. If you can't clarify the result class, use json-simple:

// import static org.hamcrest.CoreMatchers.is;
// import static org.junit.Assert.assertThat;
// import org.json.simple.JSONObject;
// import org.json.simple.JSONValue;
// import org.junit.Test;

@Test
public void json2Object() {
    // given
    String jsonString = "{\"name\" : \"John\",\"age\" : \"20\","
            + "\"address\" : \"some address\","
            + "\"someobject\" : {\"field\" : \"value\"}}";

    // when
    JSONObject object = (JSONObject) JSONValue.parse(jsonString);

    // then
    @SuppressWarnings("unchecked")
    Set<String> keySet = object.keySet();
    for (String key : keySet) {
        Object value = object.get(key);
        System.out.printf("%s=%s (%s)\n", key, value, value.getClass()
                .getSimpleName());
    }

    assertThat(object.get("age").toString(), is("20"));
}

Pros and cons of Gson and json-simple is pretty much like pros and cons of user-defined Java Object and Map. The object you define is clear for all fields (name and type), but less flexible than Map.

How can I write to the console in PHP?

Use:

function console_log($data) {
    $bt = debug_backtrace();
    $caller = array_shift($bt);

    if (is_array($data))
        $dataPart = implode(',', $data);
    else
        $dataPart = $data;

    $toSplit = $caller['file'])) . ':' .
               $caller['line'] . ' => ' . $dataPart

    error_log(end(split('/', $toSplit));
}

How do I cast a JSON Object to a TypeScript class?

I ran into a similar need. I wanted something that will give me easy transformation from/to JSON that is coming from a REST api call to/from specific class definition. The solutions that I've found were insufficient or meant to rewrite my classes' code and adding annotations or similars.

I wanted something like GSON is used in Java to serialize/deserialize classes to/from JSON objects.

Combined with a later need, that the converter will function in JS as well, I ended writing my own package.

It has though, a little bit of overhead. But when started it is very convenient in adding and editing.

You initialize the module with :

  1. conversion schema - allowing to map between fields and determine how the conversion will be done
  2. Classes map array
  3. Conversion functions map - for special conversions.

Then in your code, you use the initialized module like :

const convertedNewClassesArray : MyClass[] = this.converter.convert<MyClass>(jsonObjArray, 'MyClass');

const convertedNewClass : MyClass = this.converter.convertOneObject<MyClass>(jsonObj, 'MyClass');

or , to JSON :

const jsonObject = this.converter.convertToJson(myClassInstance);

Use this link to the npm package and also a detailed explanation to how to work with the module: json-class-converter

Also wrapped it for
Angular use in : angular-json-class-converter

How to specify jackson to only use fields - preferably globally

If you use Spring Boot, you can configure Jackson globally as follows:

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

@Configuration
public class JacksonObjectMapperConfiguration implements Jackson2ObjectMapperBuilderCustomizer {

    @Override
    public void customize(Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder) {
        jacksonObjectMapperBuilder.visibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE);
        jacksonObjectMapperBuilder.visibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
        jacksonObjectMapperBuilder.visibility(PropertyAccessor.CREATOR, JsonAutoDetect.Visibility.ANY);
    }

}

How to append new data onto a new line

I had the same issue. And I was able to solve it by using a formatter.

file_name = "abc.txt"
new_string = "I am a new string."
opened_file = open(file_name, 'a')
opened_file.write("%r\n" %new_string)
opened_file.close()

I hope this helps.

Display an image into windows forms

Here (http://www.dotnetperls.com/picturebox) there 3 ways to do this:

  • Like you are doing.
  • Using ImageLocation property of the PictureBox like:

    private void Form1_Load(object sender, EventArgs e)
    {
        PictureBox pb1 = new PictureBox();            
        pb1.ImageLocation = "../SamuderaJayaMotor.png";
        pb1.SizeMode = PictureBoxSizeMode.AutoSize;
    }
    
  • Using an image from the web like:

    private void Form1_Load(object sender, EventArgs e)
    {
        PictureBox pb1 = new PictureBox();            
        pb1.ImageLocation = "http://www.dotnetperls.com/favicon.ico";
        pb1.SizeMode = PictureBoxSizeMode.AutoSize;
    }
    

And please, be sure that "../SamuderaJayaMotor.png" is the correct path of the image that you are using.

VBA - If a cell in column A is not blank the column B equals

If you really want a vba solution you can loop through a range like this:

Sub Check()
    Dim dat As Variant
    Dim rng As Range
    Dim i As Long

    Set rng = Range("A1:A100")
    dat = rng
    For i = LBound(dat, 1) To UBound(dat, 1)
        If dat(i, 1) <> "" Then
            rng(i, 2).Value = "My Text"
        End If
    Next
End Sub

*EDIT*

Instead of using varients you can just loop through the range like this:

Sub Check()
    Dim rng As Range
    Dim i As Long

    'Set the range in column A you want to loop through
    Set rng = Range("A1:A100")
    For Each cell In rng
        'test if cell is empty
        If cell.Value <> "" Then
            'write to adjacent cell
            cell.Offset(0, 1).Value = "My Text"
        End If
    Next
End Sub

Loop through the rows of a particular DataTable

Dim row As DataRow
For Each row In dtDataTable.Rows
    Dim strDetail As String
    strDetail = row("Detail")
    Console.WriteLine("Processing Detail {0}", strDetail)
Next row

How can I create a simple message box in Python?

The PyMsgBox module does exactly this. It has message box functions that follow the naming conventions of JavaScript: alert(), confirm(), prompt() and password() (which is prompt() but uses * when you type). These function calls block until the user clicks an OK/Cancel button. It's a cross-platform, pure Python module with no dependencies outside of tkinter.

Install with: pip install PyMsgBox

Sample usage:

import pymsgbox
pymsgbox.alert('This is an alert!', 'Title')
response = pymsgbox.prompt('What is your name?')

Full documentation at http://pymsgbox.readthedocs.org/en/latest/

QtCreator: No valid kits found

No valid Kits found The problem occurs because qt-creator don't know the versions of your qt, your compiler or your debugger. First off, let's solve the Qt versions. It may normally solve the others too ;).

You try to create a new project, run select a kit and then there is no kit available in the list.

Follow the steps:

  1. Execute in your terminal the command: sudo apt-get install qt5-default to install qt version 5.
  2. Verify the version of your Qt and the location of your qmake file. Do this by executing in your terminal the command qmake --version. You may have a result similar to this line. QMake version 3.1 Using Qt version 5.9.5 in /usr/lib/x86_64-linux-gnu. What's important here is the location /usr/lib/x86_64-linux-gnu.
  3. Open your Qt-creator.
  4. Go to "Tools>Options" or "Outils>Options"
  5. Select the Qt Versions combobox and select and click "Add" or "Ajouter"
  6. Then find the qmake file in the location of step 2. Here /usr/lib/x86_64-linux-gnu/qt5/bin/ here you have the qmake file for qt5. Open it, click Apply.
  7. Go to "Kits" combobox. Select Desktop(by default) or Desktop(par défaut). Then scroll down to the button to select Qt version: and list down to select the version you just add. 8.Then apply all. Check your compiler and debugger and it's ok. You're done.

Yes I ...

Hope it's help ;)

Reading and writing value from a textfile by using vbscript code

To Write

Set objFileToWrite = CreateObject("Scripting.FileSystemObject").OpenTextFile("C:\listfile.txt",2,true)
objFileToWrite.WriteLine(data)
objFileToWrite.Close
Set objFileToWrite = Nothing

OpenTextFile parameters:

<filename>, IOMode (1=Read,2=write,8=Append), Create (true,false), Format (-2=System Default,-1=Unicode,0=ASCII)

To Read the entire file

Set objFileToRead = CreateObject("Scripting.FileSystemObject").OpenTextFile("C:\listfile.txt",1)
strFileText = objFileToRead.ReadAll()
objFileToRead.Close
Set objFileToRead = Nothing

To Read line by line

Set objFileToRead = CreateObject("Scripting.FileSystemObject").OpenTextFile("C:\listfile.txt",1)
Dim strLine
do while not objFileToRead.AtEndOfStream
     strLine = objFileToRead.ReadLine()
     'Do something with the line
loop
objFileToRead.Close
Set objFileToRead = Nothing

How do you update Xcode on OSX to the latest version?

If you want the latest Beta, it will not be in the AppStore. Instead you have to login to https://developer.apple.com and download from there.

In Node.js, how do I turn a string to a json?

use the JSON function >

JSON.parse(theString)

Switch statement fallthrough in C#?

(Copy/paste of an answer I provided elsewhere)

Falling through switch-cases can be achieved by having no code in a case (see case 0), or using the special goto case (see case 1) or goto default (see case 2) forms:

switch (/*...*/) {
    case 0: // shares the exact same code as case 1
    case 1:
        // do something
        goto case 2;
    case 2:
        // do something else
        goto default;
    default:
        // do something entirely different
        break;
}

CMake link to external library

arrowdodger's answer is correct and preferred on many occasions. I would simply like to add an alternative to his answer:

You could add an "imported" library target, instead of a link-directory. Something like:

# Your-external "mylib", add GLOBAL if the imported library is located in directories above the current.
add_library( mylib SHARED IMPORTED )
# You can define two import-locations: one for debug and one for release.
set_target_properties( mylib PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/res/mylib.so )

And then link as if this library was built by your project:

TARGET_LINK_LIBRARIES(GLBall mylib)

Such an approach would give you a little more flexibility: Take a look at the add_library( ) command and the many target-properties related to imported libraries.

I do not know if this will solve your problem with "updated versions of libs".

Determine if Android app is being used for the first time

You can use the SharedPreferences to identify if it is the "First time" the app is launched. Just use a Boolean variable ("my_first_time") and change its value to false when your task for "first time" is over.

This is my code to catch the first time you open the app:

final String PREFS_NAME = "MyPrefsFile";

SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);

if (settings.getBoolean("my_first_time", true)) {
    //the app is being launched for first time, do something        
    Log.d("Comments", "First time");

             // first time task

    // record the fact that the app has been started at least once
    settings.edit().putBoolean("my_first_time", false).commit(); 
}

Conditionally displaying JSF components

In addition to previous post you can have

<h:form rendered="#{!bean.boolvalue}" />
<h:form rendered="#{bean.textvalue == 'value'}" />

Jsf 2.0

SQL Server: Maximum character length of object names

Yes, it is 128, except for temp tables, whose names can only be up to 116 character long. It is perfectly explained here.

And the verification can be easily made with the following script contained in the blog post before:

DECLARE @i NVARCHAR(800)
SELECT @i = REPLICATE('A', 116)
SELECT @i = 'CREATE TABLE #'+@i+'(i int)'
PRINT @i
EXEC(@i)

How to "crop" a rectangular image into a square with CSS?

Use CSS: overflow:

.thumb {
   width:230px;
   height:230px;
   overflow:hidden
}

jQuery - select the associated label element of a input field

There are two ways to specify label for element:

  1. Setting label's "for" attribute to element's id
  2. Placing element inside label

So, the proper way to find element's label is

   var $element = $( ... )

   var $label = $("label[for='"+$element.attr('id')+"']")
   if ($label.length == 0) {
     $label = $element.closest('label')
   }

   if ($label.length == 0) {
     // label wasn't found
   } else {
     // label was found
   }

Conveniently map between enum and int / String

given:

public enum BonusType { MONTHLY(0), YEARLY(1), ONE_OFF(2) }

BonusType bonus = YEARLY;

System.out.println(bonus.Ordinal() + ":" + bonus)

Output: 1:YEARLY

Phone Number Validation MVC

Or you can use JQuery - just add your input field to the class "phone" and put this in your script section:

$(".phone").keyup(function () {
        $(this).val($(this).val().replace(/^(\d{3})(\d{3})(\d)+$/, "($1)$2-$3"));

There is no error message but you can see that the phone number is not correctly formatted until you have entered all ten digits.

jQuery multiselect drop down menu

Are you looking to do something like this http://jsfiddle.net/robert/xhHkG/

$('#transactionType').attr({
    'multiple': true,
    'size' : 10
});

Put that in a $(function() {...}) or some other onload

Edit

Reread your question, you're not really looking for a multiple select... but a dropdown box that allows you to select multiple. Yeah, probably best to use a plugin for that or write it from the ground up, it's not a "quick answer" type deal though.

Get the device width in javascript

Lumia phones give wrong screen.width (at least on emulator). So maybe Math.min(window.innerWidth || Infinity, screen.width) will work on all devices?

Or something crazier:

for (var i = 100; !window.matchMedia('(max-device-width: ' + i + 'px)').matches; i++) {}
var deviceWidth = i;

What does 'git blame' do?

The git blame command is used to know who/which commit is responsible for the latest changes made to a file. The author/commit of each line can also been seen.

git blame filename (commits responsible for changes for all lines in code)

git blame filename -L 0,10 (commits responsible for changes from line "0" to line "10")

There are many other options for blame, but generally these could help.

Generate Row Serial Numbers in SQL Query

SELECT ROW_NUMBER()  OVER (ORDER BY  ColumnName1) As SrNo, ColumnName1,  ColumnName2 FROM  TableName

How does HTTP_USER_AGENT work?

The user agent string is a text that the browsers themselves send to the webserver to identify themselves, so that websites can send different content based on the browser or based on browser compatibility.

Mozilla is a browser rendering engine (the one at the core of Firefox) and the fact that Chrome and IE contain the string Mozilla/4 or /5 identifies them as being compatible with that rendering engine.

Difference between == and ===

>>> is unsigned-shift; it'll insert 0. >> is signed, and will extend the sign bit.

JLS 15.19 Shift Operators

The shift operators include left shift <<, signed right shift >>, and unsigned right shift >>>.

The value of n>>s is n right-shifted s bit positions with sign-extension.

The value of n>>>s is n right-shifted s bit positions with zero-extension.

    System.out.println(Integer.toBinaryString(-1));
    // prints "11111111111111111111111111111111"
    System.out.println(Integer.toBinaryString(-1 >> 16));
    // prints "11111111111111111111111111111111"
    System.out.println(Integer.toBinaryString(-1 >>> 16));
    // prints "1111111111111111"

To make things more clear adding positive counterpart

System.out.println(Integer.toBinaryString(121));
// prints "1111001"
System.out.println(Integer.toBinaryString(121 >> 1));
// prints "111100"
System.out.println(Integer.toBinaryString(121 >>> 1));
// prints "111100"

Since it is positive both signed and unsigned shifts will add 0 to left most bit.

Related questions

Compiler error "archive for required library could not be read" - Spring Tool Suite

I face with the same issue. I deleted the local repository and relaunched the ID. It worked fine .

make: Nothing to be done for `all'

That is not an error; the make command in unix works based on the timestamps. I.e let's say if you have made certain changes to factorial.cpp and compile using make then make shows the information that only the cc -o factorial.cpp command is executed. Next time if you execute the same command i.e make without making any changes to any file with .cpp extension the compiler says that the output file is up to date. The compiler gives this information until we make certain changes to any file.cpp.

The advantage of the makefile is that it reduces the recompiling time by compiling the only files that are modified and by using the object (.o) files of the unmodified files directly.

Is there a developers api for craigslist.org

Craiglist is pretty stingy with their data , they even go out of their way to block scraping. If you use ruby here is a gem I wrote to help scrape craiglist data you can search through multiple cities , calculate average price ect...

How to compare binary files to check if they are the same?

Use cmp command. This will either exit cleanly if they are binary equal, or it will print out where the first difference occurs and exit.

How to autosize a textarea using Prototype?

Like the answer of @memical.

However I found some improvements. You can use the jQuery height() function. But be aware of padding-top and padding-bottom pixels. Otherwise your textarea will grow too fast.

$(document).ready(function() {
  $textarea = $("#my-textarea");

  // There is some diff between scrollheight and height:
  //    padding-top and padding-bottom
  var diff = $textarea.prop("scrollHeight") - $textarea.height();
  $textarea.live("keyup", function() {
    var height = $textarea.prop("scrollHeight") - diff;
    $textarea.height(height);
  });
});

Parse date without timezone javascript

You can use this code

var stringDate = "2005-07-08T00:00:00+0000";
var dTimezone = new Date();
var offset = dTimezone.getTimezoneOffset() / 60;
var date = new Date(Date.parse(stringDate));
date.setHours(date.getHours() + offset);

How can I install Visual Studio Code extensions offline?

If you are looking for a scripted solution:

  1. Get binary download URL: you can use an API, but be warned that there is no documentation for it. This API can return an URL to download .vsix files (see example below)
  2. Download the binary
  3. Carefully unzip the binary into ~/.vscode/extensions/: you need to modify unzipped directory name, remove one file and move/rename another one.

For API start by looking at following example, and for hints how to modify request head to https://github.com/Microsoft/vscode/blob/master/src/vs/platform/extensionManagement/common/extensionGalleryService.ts.

POST https://marketplace.visualstudio.com/_apis/public/gallery/extensionquery?api-version=5.1-preview HTTP/1.1
content-type: application/json

{
    "filters": [
        {
        "criteria": [
            {
                "filterType": 8,
                "value": "Microsoft.VisualStudio.Code",
            },
            {
                "filterType": 7,
                "value": "ms-python.python",
            }
        ],
        "pageNumber": 1,
        "pageSize": 10,
        "sortBy": 0,
        "sortOrder": 0,
        }
    ],
    "assetTypes": ["Microsoft.VisualStudio.Services.VSIXPackage"],
    "flags": 514,
}

Explanations to the above example:

  • "filterType": 8 - FilterType.Target more FilterTypes
  • "filterType": 7 - FilterType.ExtensionName more FilterTypes
  • "flags": 514 - 0x2 | 0x200 - Flags.IncludeFiles | Flags.IncludeLatestVersionOnly - more Flags
    • to get flag decimal value you can run python -c "print(0x2|0x200)"
  • "assetTypes": ["Microsoft.VisualStudio.Services.VSIXPackage"] - to get only link to .vsix file more AssetTypes

Show Current Location and Nearby Places and Route between two places using Google Maps API in Android

You can use google map Obtaining User Location here!

After obtaining your location(longitude and latitude), you can use google place api

This code can help you get your location easily but not the best way.

locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String bestProvider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(bestProvider);  

How to define an optional field in protobuf 3

To expand on @cybersnoopy 's suggestion here

if you had a .proto file with a message like so:

message Request {
    oneof option {
        int64 option_value = 1;
    }
}

You can make use of the case options provided (java generated code):

So we can now write some code as follows:

Request.OptionCase optionCase = request.getOptionCase();
OptionCase optionNotSet = OPTION_NOT_SET;

if (optionNotSet.equals(optionCase)){
    // value not set
} else {
    // value set
}

JavaScript ES6 promise for loop

As you already hinted in your question, your code creates all promises synchronously. Instead they should only be created at the time the preceding one resolves.

Secondly, each promise that is created with new Promise needs to be resolved with a call to resolve (or reject). This should be done when the timer expires. That will trigger any then callback you would have on that promise. And such a then callback (or await) is a necessity in order to implement the chain.

With those ingredients, there are several ways to perform this asynchronous chaining:

  1. With a for loop that starts with an immediately resolving promise

  2. With Array#reduce that starts with an immediately resolving promise

  3. With a function that passes itself as resolution callback

  4. With ECMAScript2017's async / await syntax

  5. With ECMAScript2020's for await...of syntax

See a snippet and comments for each of these options below.

1. With for

You can use a for loop, but you must make sure it doesn't execute new Promise synchronously. Instead you create an initial immediately resolving promise, and then chain new promises as the previous ones resolve:

_x000D_
_x000D_
for (let i = 0, p = Promise.resolve(); i < 10; i++) {
    p = p.then(_ => new Promise(resolve =>
        setTimeout(function () {
            console.log(i);
            resolve();
        }, Math.random() * 1000)
    ));
}
_x000D_
_x000D_
_x000D_

2. With reduce

This is just a more functional approach to the previous strategy. You create an array with the same length as the chain you want to execute, and start out with an immediately resolving promise:

_x000D_
_x000D_
[...Array(10)].reduce( (p, _, i) => 
    p.then(_ => new Promise(resolve =>
        setTimeout(function () {
            console.log(i);
            resolve();
        }, Math.random() * 1000)
    ))
, Promise.resolve() );
_x000D_
_x000D_
_x000D_

This is probably more useful when you actually have an array with data to be used in the promises.

3. With a function passing itself as resolution-callback

Here we create a function and call it immediately. It creates the first promise synchronously. When it resolves, the function is called again:

_x000D_
_x000D_
(function loop(i) {
    if (i < 10) new Promise((resolve, reject) => {
        setTimeout( () => {
            console.log(i);
            resolve();
        }, Math.random() * 1000);
    }).then(loop.bind(null, i+1));
})(0);
_x000D_
_x000D_
_x000D_

This creates a function named loop, and at the very end of the code you can see it gets called immediately with argument 0. This is the counter, and the i argument. The function will create a new promise if that counter is still below 10, otherwise the chaining stops.

The call to resolve() will trigger the then callback which will call the function again. loop.bind(null, i+1) is just a different way of saying _ => loop(i+1).

4. With async/await

Modern JS engines support this syntax:

_x000D_
_x000D_
(async function loop() {
    for (let i = 0; i < 10; i++) {
        await new Promise(resolve => setTimeout(resolve, Math.random() * 1000));
        console.log(i);
    }
})();
_x000D_
_x000D_
_x000D_

It may look strange, as it seems like the new Promise() calls are executed synchronously, but in reality the async function returns when it executes the first await. Every time an awaited promise resolves, the function's running context is restored, and proceeds after the await, until it encounters the next one, and so it continues until the loop finishes.

As it may be a common thing to return a promise based on a timeout, you could create a separate function for generating such a promise. This is called promisifying a function, in this case setTimeout. It may improve the readability of the code:

_x000D_
_x000D_
const delay = ms => new Promise(resolve => setTimeout(resolve, ms));

(async function loop() {
    for (let i = 0; i < 10; i++) {
        await delay(Math.random() * 1000);
        console.log(i);
    }
})();
_x000D_
_x000D_
_x000D_

5. With for await...of

With EcmaScript 2020, the for await...of found its way to modern JavaScript engines. Although it does not really reduce code in this case, it allows to isolate the definition of the random interval chain from the actual iteration of it:

_x000D_
_x000D_
const delay = ms => new Promise(resolve => setTimeout(resolve, ms));
async function * randomDelays(count ,max) {
    for (let i = 0; i < count; i++) yield delay(Math.random() * max).then(() => i);
}

(async function loop() {
    for await (let i of randomDelays(10, 1000)) console.log(i);
})();
_x000D_
_x000D_
_x000D_

How can I get double quotes into a string literal?

Thankfully, with C++11 there is also the more pleasing approach of using raw string literals.

printf("She said \"time flies like an arrow, but fruit flies like a banana\".");

Becomes:

printf(R"(She said "time flies like an arrow, but fruit flies like a banana".)");

With respect to the addition of brackets after the opening quote, and before the closing quote, note that they can be almost any combination of up to 16 characters, helping avoid the situation where the combination is present in the string itself. Specifically:

any member of the basic source character set except: space, the left parenthesis (, the right parenthesis ), the backslash , and the control characters representing horizontal tab, vertical tab, form feed, and newline" (N3936 §2.14.5 [lex.string] grammar) and "at most 16 characters" (§2.14.5/2)

How much clearer it makes this short strings might be debatable, but when used on longer formatted strings like HTML or JSON, it's unquestionably far clearer.

What does "make oldconfig" do exactly in the Linux kernel makefile?

It's torture. Instead of including a generic conf file, they make you hit return 9000 times to generate one.

Sorting a List<int>

Sort a list of integers descending

class Program
    {       
        private class SortIntDescending : IComparer<int>
        {
            int IComparer<int>.Compare(int a, int b) //implement Compare
            {              
                if (a > b)
                    return -1; //normally greater than = 1
                if (a < b)
                    return 1; // normally smaller than = -1
                else
                    return 0; // equal
            }
        }

        static List<int> intlist = new List<int>(); // make a list

        static void Main(string[] args)
        {
            intlist.Add(5); //fill the list with 5 ints
            intlist.Add(3);
            intlist.Add(5);
            intlist.Add(15);
            intlist.Add(7);

            Console.WriteLine("Unsorted list :");
            Printlist(intlist);

            Console.WriteLine();
            // intlist.Sort(); uses the default Comparer, which is ascending
            intlist.Sort(new SortIntDescending()); //sort descending

            Console.WriteLine("Sorted descending list :");
            Printlist(intlist);

            Console.ReadKey(); //wait for keydown
        }

        static void Printlist(List<int> L)
        {
            foreach (int i in L) //print on the console
            {
                Console.WriteLine(i);
            }
        }
    }

How do I set hostname in docker-compose?

Based on docker documentation: https://docs.docker.com/compose/compose-file/#/command

I simply put hostname: <string> in my docker-compose file.

E.g.:

[...]

lb01:
  hostname: at-lb01
  image: at-client-base:v1

[...]

and container lb01 picks up at-lb01 as hostname.

Cannot start MongoDB as a service

If you look in the service details, you can see that the command to start the service is something like:

"C:\Program Files\MongoDB\bin\mongod" --config  C:\Program Files\MongoDB\mongod.cfg  --service 

The MongoDB team forgot to add the " around the --config option. So just edit the registry to correct it and it will work.

How can I convert tabs to spaces in every file of a directory?

Download and run the following script to recursively convert hard tabs to soft tabs in plain text files.

Execute the script from inside the folder which contains the plain text files.

#!/bin/bash

find . -type f -and -not -path './.git/*' -exec grep -Iq . {} \; -and -print | while read -r file; do {
    echo "Converting... "$file"";
    data=$(expand --initial -t 4 "$file");
    rm "$file";
    echo "$data" > "$file";
}; done;

Search for all files in project containing the text 'querystring' in Eclipse

Yes, you can do this quite easily. Click on your project in the project explorer or Navigator, go to the Search menu at the top, click File..., input your search string, and make sure that 'Selected Resources' or 'Enclosing Projects' is selected, then hit search. The alternative way to open the window is with Ctrl-H. This may depend on your keyboard accelerator configuration.

More details: http://www.ehow.com/how_4742705_file-eclipse.html and http://www.avajava.com/tutorials/lessons/how-do-i-do-a-find-and-replace-in-multiple-files-in-eclipse.html

alt text
(source: avajava.com)

One liner for If string is not null or empty else

You can write your own Extension method for type String :-

 public static string NonBlankValueOf(this string source)
 {
    return (string.IsNullOrEmpty(source)) ? "0" : source;
 }

Now you can use it like with any string type

FooTextBox.Text = strFoo.NonBlankValueOf();

Using iFrames In ASP.NET

You can think of an iframe as an embedded browser window that you can put on an HTML page to show another URL inside it. This URL can be totally distinct from your web site/app.

You can put an iframe in any HTML page, so you could put one inside a contentplaceholder in a webform that has a Masterpage and it will appear with whatever URL you load into it (via Javascript, or C# if you turn your iframe into a server-side control (runat='server') on the final HTML page that your webform produces when requested.

And you can load a URL into your iframe that is a .aspx page.

But - iframes have nothing to do with the ASP.net mechanism. They are HTML elements that can be made to run server-side, but they are essentially 'dumb' and unmanaged/unconnected to the ASP.Net mechanisms - don't confuse a Contentplaceholder with an iframe.

Incidentally, the use of iframes is still contentious - do you really need to use one? Can you afford the negative trade-offs associated with them e.g. lack of navigation history ...?

How can I enable or disable the GPS programmatically on Android?

You just need to remove the LocationListener from LocationManager

manager.removeUpdates(listener);

How can I submit a form using JavaScript?

If your form does not have any id, but it has a class name like theForm, you can use the below statement to submit it:

document.getElementsByClassName("theForm")[0].submit();

How to convert a datetime to string in T-SQL

This has been answered by a lot of people, but I feel like the simplest solution has been left out.

SQL SERVER (I believe its 2012+) has implicit string equivalents for DATETIME2 as shown here

Look at the section on "Supported string literal formats for datetime2"

To answer the OPs question explicitly:

DECLARE @myVar NCHAR(32)
DECLARE @myDt DATETIME2
SELECT @myVar = @GETDATE()
SELECT @myDt = @myVar
PRINT(@myVar)
PRINT(@myDt)

output:

Jan 23 2019 12:24PM             
2019-01-23 12:24:00.0000000

Note: The first variable (myVar) is actually holding the value '2019-01-23 12:24:00.0000000' as well. It just gets formatted to Jan 23 2019 12:24PM due to default formatting set for SQL SERVER that gets called on when you use PRINT. Don't get tripped up here by that, the actual string in (myVer) = '2019-01-23 12:24:00.0000000'

Excel Formula: Count cells where value is date

A bit long winded but it works for me: try this::

=SUM(IF(OR(ISBLANK(AU2), NOT(ISERR(YEAR(AU2)))),0,1)
 +IF(OR(ISBLANK(AV2), NOT(ISERR(YEAR(AV2)))),0,1))

first part of if will allow cell to be blank or if there is something in the cell it tries to convert to a year, if there is an error or there is something other than a date result = 1, do the same for each cell and sum the result

Media Player called in state 0, error (-38,0)

You get this message in the logs, because you do something that is not allowed in the current state of your MediaPlayer instance.

Therefore you should always register an error handler to catch those things (as @tidbeck suggested).

At first, I advice you to take a look at the documentation for the MediaPlayer class and get an understanding of what that with states means. See: http://developer.android.com/reference/android/media/MediaPlayer.html#StateDiagram

Your mistake here could well be one of the common ones, the others wrote here, but in general, I would take a look at the documentation of what methods are valid to call in what state: http://developer.android.com/reference/android/media/MediaPlayer.html#Valid_and_Invalid_States

In my example it was the method mediaPlayer.CurrentPosition, that I called while the media player was in a state, where it was not allowed to call this property.

WCF on IIS8; *.svc handler mapping doesn't work

More specifically:

  1. Run Server Manager (on task bar and start menu)
  2. Choose the server to administer (probably local server)
  3. Scroll down to "Roles and Features" section.
  4. Choose "Add Role or Feature" from Tasks drop down
  5. On "Add Role or Feature Wizard" dialog, click down to "Features" in list of pages on the left.
  6. Expand ".Net 3.5" or ".Net 4.5", depending on what you have installed. (you can go back up to "roles" screen to add if you don't have.
  7. Under "WCF Services", check the box for "HTTP-Activation". You can also add non-http types if you know you need them (tcp, named pipes, etc).
  8. Click "Install" Button.

Can I extend a class using more than 1 class in PHP?

Use traits as base classes. Then use them in a parent class. Extend it .

trait business{
  function sell(){

  }

  function buy(){

  }

  function collectMoney(){
  }

}

trait human{

   function think(){

   }

   function speak(){

   }

}

class BusinessPerson{
  use business;
  use human;
  // If you have more traits bring more
}


class BusinessWoman extends BusinessPerson{

   function getPregnant(){

   }

}


$bw = new BusinessWoman();
$bw ->speak();
$bw->getPregnant();

See now business woman logically inherited business and human both;

How do you share constants in NodeJS modules?

You can explicitly export it to the global scope with global.FOO = 5. Then you simply need to require the file, and not even save your return value.

But really, you shouldn't do that. Keeping things properly encapsulated is a good thing. You have the right idea already, so keep doing what you're doing.

Push origin master error on new repository

I mistankly put a space after the - so instead of -m I had - m Just something to look for.

What is the difference between <section> and <div>?

<section> marks up a section, <div> marks up a generic block with no associated semantics.

How can I find all the subsets of a set, with exactly n elements?

Another solution using recursion:

def subsets(nums: List[int]) -> List[List[int]]:
    n = len(nums)
    output = [[]]
    
    for num in nums:
        output += [curr + [num] for curr in output]
    
    return output

Starting from empty subset in output list. At each step we take a new integer into consideration and generates new subsets from the existing ones.

What is the purpose of XSD files?

XSD files are used to validate that XML files conform to a certain format.

In that respect they are similar to DTDs that existed before them.

The main difference between XSD and DTD is that XSD is written in XML and is considered easier to read and understand.

How to write a function that takes a positive integer N and returns a list of the first N natural numbers

Here are a few ways to create a list with N of continuous natural numbers starting from 1.

1 range:

def numbers(n): 
    return range(1, n+1);

2 List Comprehensions:

def numbers(n):
    return [i for i in range(1, n+1)]

You may want to look into the method xrange and the concepts of generators, those are fun in python. Good luck with your Learning!

open program minimized via command prompt

You could try using the third-party tool called NirCmd. It is a genuine, free command line utility. If or when you have it, use this code in a batch file:

title Open Word
nircmd win hide title "Open Word"
start "C:\Program" "Files" "(x86)\Microsoft" "Office\Office12\WINWORD.exe
nircmd wait 20
nircmd win min foreground
exit

This program, in order, changes its title, hides itself according to its title, starts Word, waits 20 milliseconds as a buffer for Word to settle, minimizes Word by assuming it is now the top window, and then exits itself. This program should work as intended as long as their are no key presses or clicks in that ~50 millisecond time window, which shouldn't be hard.

As for installing nircmd on your computer, use this link, and click "Download NirCmd" at the bottom of the page. Save the .zip folder to a normal directory (like "My Documents"), extract it, and copy "nircmd.exe" to %systemroot%\system32, and there you go. Now you have nircmd included with your command line utilities.

Resizing a button

Another alternative is that you are allowed to have multiple classes in a tag. Consider:

 <div class="button big">This is a big button</div>
 <div class="button small">This is a small button</div>

And the CSS:

 .button {
     /* all your common button styles */
 }

 .big {
     height: 60px;
     width: 100px;
 }
 .small {
     height: 40px;
     width: 70px;
 }

and so on.

Best way to test if a row exists in a MySQL table

I'd go with COUNT(1). It is faster than COUNT(*) because COUNT(*) tests to see if at least one column in that row is != NULL. You don't need that, especially because you already have a condition in place (the WHERE clause). COUNT(1) instead tests the validity of 1, which is always valid and takes a lot less time to test.

Load CSV file with Spark

Are you sure that all the lines have at least 2 columns? Can you try something like, just to check?:

sc.textFile("file.csv") \
    .map(lambda line: line.split(",")) \
    .filter(lambda line: len(line)>1) \
    .map(lambda line: (line[0],line[1])) \
    .collect()

Alternatively, you could print the culprit (if any):

sc.textFile("file.csv") \
    .map(lambda line: line.split(",")) \
    .filter(lambda line: len(line)<=1) \
    .collect()

SQL GROUP BY CASE statement with aggregate function

My guess is that you don't really want to GROUP BY some_product.

The answer to: "Is there a way to GROUP BY a column alias such as some_product in this case, or do I need to put this in a subquery and group on that?" is: You can not GROUP BY a column alias.

The SELECT clause, where column aliases are assigned, is not processed until after the GROUP BY clause. An inline view or common table expression (CTE) could be used to make the results available for grouping.

Inline view:

select ...
from (select ... , CASE WHEN col1 > col2 THEN SUM(col3*col4) ELSE 0 END AS some_product
   from ...
   group by col1, col2 ... ) T
group by some_product ...

CTE:

with T as (select ... , CASE WHEN col1 > col2 THEN SUM(col3*col4) ELSE 0 END AS some_product
   from ...
   group by col1, col2 ... )
select ...
from T
group by some_product ... 

Android: Clear Activity Stack

When you call startActivity on the last activity you could always use

Intent.FLAG_ACTIVITY_CLEAR_TOP

as a flag on that intent.

Read more about the flag here.

CSS float right not working correctly

you need to wrap your text inside div and float it left while wrapper div should have height, and I've also added line height for vertical alignment

<div style="border-bottom-width: 1px; border-bottom-style: solid; border-bottom-color: gray;height:30px;">
   <div style="float:left;line-height:30px;">Contact Details</div>

    <button type="button" class="edit_button" style="float: right;">My Button</button>

</div>

also js fiddle here =) http://jsfiddle.net/xQgSm/

Storing files in SQL Server

You might read up on FILESTREAM. Here is some info from the docs that should help you decide:

If the following conditions are true, you should consider using FILESTREAM:

  • Objects that are being stored are, on average, larger than 1 MB.
  • Fast read access is important.
  • You are developing applications that use a middle tier for application logic.

For smaller objects, storing varbinary(max) BLOBs in the database often provides better streaming performance.

CSS Printing: Avoiding cut-in-half DIVs between pages?

page-break-inside: avoid; does not seem to always work. It seems to take into account the height and positioning of container elements.

For example, inline-block elements that are taller than the page will get clipped.

I was able to restore working page-break-inside: avoid; functionality by identifying a container element with display: inline-block and adding:

@media print {
    .container { display: block; } /* this is key */

    div, p, ..etc { page-break-inside: avoid; }
}

Hope this helps folks who complain that "page-break-inside does not work".

What are alternatives to ExtJS?

Nothing compares to in terms of community size and presence on StackOverflow. Despite previous controversy, Ext JS now has a GPLv3 open source license. Its learning curve is long, but it can be quite rewarding once learned. Ext JS lacks a Material Design theme, and the team has repeatedly refused to release the source code on GitHub. For mobile, one must use the separate Sencha Touch library.

Have in mind also that,

large JavaScript libraries, such as YUI, have been receiving less attention from the community. Many developers today look at large JavaScript libraries as walled gardens they don’t want to be locked into.

-- Announcement of YUI development being ceased

That said, below are a number of Ext JS alternatives currently available.

Leading client widget libraries

  1. Blueprint is a React-based UI toolkit developed by big data analytics company Palantir in TypeScript, and "optimized for building complex data-dense interfaces for desktop applications". Actively developed on GitHub as of May 2019, with comprehensive documentation. Components range from simple (chips, toast, icons) to complex (tree, data table, tag input with autocomplete, date range picker. No accordion or resizer.

    Blueprint targets modern browsers (Chrome, Firefox, Safari, IE 11, and Microsoft Edge) and is licensed under a modified Apache license.

    Sandbox / demoGitHubDocs

  2. Webix - an advanced, easy to learn, mobile-friendly, responsive and rich free&open source JavaScript UI components library. Webix spun off from DHTMLX Touch (a project with 8 years of development behind it - see below) and went on to become a standalone UI components framework. The GPL3 edition allows commercial use and lets non-GPL applications using Webix keep their license, e.g. MIT, via a license exemption for FLOSS. Webix has 55 UI widgets, including trees, grids, treegrids and charts. Funding comes from a commercial edition with some advanced widgets (Pivot, Scheduler, Kanban, org chart etc.). Webix has an extensive list of free and commercial widgets, and integrates with most popular frameworks (React, Vue, Meteor, etc) and UI components.

    Webix

    Skins look modern, and include a Material Design theme. The Touch theme also looks quite Material Design-ish. See also the Skin Builder.

    Minimal GitHub presence, but includes the library code, and the documentation (which still needs major improvements). Webix suffers from a having a small team and a lack of marketing. However, they have been responsive to user feedback, both on GitHub and on their forum.

    The library was lean (128Kb gzip+minified for all 55 widgets as of ~2015), faster than ExtJS, dojo and others, and the design is pleasant-looking. The current version of Webix (v6, as of Nov 2018) got heavier (400 - 676kB minified but NOT gzipped).

    The demos on Webix.com look and function great. The developer, XB Software, uses Webix in solutions they build for paying customers, so there's likely a good, funded future ahead of it.

    Webix aims for backwards compatibility down to IE8, and as a result carries some technical debt.

    WikipediaGitHubPlayground/sandboxAdmin dashboard demoDemosWidget samples

  3. react-md - MIT-licensed Material Design UI components library for React. Responsive, accessible. Implements components from simple (buttons, cards) to complex (sortable tables, autocomplete, tags input, calendars). One lead author, ~1900 GitHub stars.

  4. - jQuery-based UI toolkit with 40+ basic open-source widgets, plus commercial professional widgets (grids, trees, charts etc.). Responsive&mobile support. Works with Bootstrap and AngularJS. Modern, with Material Design themes. The documentation is available on GitHub, which has enabled numerous contributions from users (4500+ commits, 500+ PRs as of Jan 2015).

    enter image description here

    Well-supported commercially, claiming millions of developers, and part of a large family of developer tools. Telerik has received many accolades, is a multi-national company (Bulgaria, US), was acquired by Progress Software, and is a thought leader.

    A Kendo UI Professional developer license costs $700 and posting access to most forums is conditioned upon having a license or being in the trial period.

    [Wikipedia] • GitHub/TelerikDemosPlaygroundTools

  5. OpenUI5 - jQuery-based UI framework with 180 widgets, Apache 2.0-licensed and fully-open sourced and funded by German software giant SAP SE.

    OpenUI5

    The community is much larger than that of Webix, SAP is hiring developers to grow OpenUI5, and they presented OpenUI5 at OSCON 2014.

    The desktop themes are rather lackluster, but the Fiori design for web and mobile looks clean and neat.

    WikipediaGitHubMobile-first controls demosDesktop controls demosSO

  6. DHTMLX - JavaScript library for building rich Web and Mobile apps. Looks most like ExtJS - check the demos. Has been developed since 2005 but still looks modern. All components except TreeGrid are available under GPLv2 but advanced features for many components are only available in the commercial PRO edition - see for example the tree. Claims to be used by many Fortune 500 companies.

    DHTMLX

    Minimal presence on GitHub (the main library code is missing) and StackOverflow but active forum. The documentation is not available on GitHub, which makes it difficult to improve by the community.

  7. Polymer, a Web Components polyfill, plus Polymer Paper, Google's implementation of the Material design. Aimed at web and mobile apps. Doesn't have advanced widgets like trees or even grids but the controls it provides are mobile-first and responsive. Used by many big players, e.g. IBM or USA Today.

    Polymer Paper Elements

  8. Ant Design claims it is "a design language for background applications", influenced by "nature" and helping designers "create low-entropy atmosphere for developer team". That's probably a poor translation from Chinese for "UI components for enterprise web applications". It's a React UI library written in TypeScript, with many components, from simple (buttons, cards) to advanced (autocomplete, calendar, tag input, table).

    The project was born in China, is popular with Chinese companies, and parts of the documentation are available only in Chinese. Quite popular on GitHub, yet it makes the mistake of splitting the community into Chinese and English chat rooms. The design looks Material-ish, but fonts are small and the information looks lost in a see of whitespace.

  9. PrimeUI - collection of 45+ rich widgets based on jQuery UI. Apache 2.0 license. Small GitHub community. 35 premium themes available.

  10. qooxdoo - "a universal JavaScript framework with a coherent set of individual components", developed and funded by German hosting provider 1&1 (see the contributors, one of the world's largest hosting companies. GPL/EPL (a business-friendly license).

    Mobile themes look modern but desktop themes look old (gradients).

    Qooxdoo

    WikipediaGitHubWeb/Mobile/Desktop demosWidgets Demo browserWidget browserSOPlaygroundCommunity

  11. jQuery UI - easy to pick up; looks a bit dated; lacks advanced widgets. Of course, you can combine it with independent widgets for particular needs, e.g. trees or other UI components, but the same can be said for any other framework.

  12. + Angular UI. While Angular is backed by Google, it's being radically revamped in the upcoming 2.0 version, and "users will need to get to grips with a new kind of architecture. It's also been confirmed that there will be no migration path from Angular 1.X to 2.0". Moreover, the consensus seems to be that Angular 2 won't really be ready for use until a year or two from now. Angular UI has relatively few widgets (no trees, for example).

  13. DojoToolkit and their powerful Dijit set of widgets. Completely open-sourced and actively developed on GitHub, but development is now (Nov 2018) focused on the new dojo.io framework, which has very few basic widgets. BSD/AFL license. Development started in 2004 and the Dojo Foundation is being sponsored by IBM, Google, and others - see Wikipedia. 7500 questions here on SO.

    Dojo Dijit

    Themes look desktop-oriented and dated - see the theme tester in dijit. The official theme previewer is broken and only shows "Claro". A Bootstrap theme exists, which looks a lot like Bootstrap, but doesn't use Bootstrap classes. In Jan 2015, I started a thread on building a Material Design theme for Dojo, which got quite popular within the first hours. However, there are questions regarding building that theme for the current Dojo 1.10 vs. the next Dojo 2.0. The response to that thread shows an active and wide community, covering many time zones.

    Unfortunately, Dojo has fallen out of popularity and fewer companies appear to use it, despite having (had?) a strong foothold in the enterprise world. In 2009-2012, its learning curve was steep and the documentation needed improvements; while the documentation has substantially improved, it's unclear how easy it is to pick up Dojo nowadays.

    With a Material Design theme, Dojo (2.0?) might be the killer UI components framework.

    WikipediaGitHubThemesDemosDesktop widgetsSO

  14. Enyo - front-end library aimed at mobile and TV apps (e.g. large touch-friendly controls). Developed by LG Electronix and Apache-licensed on GitHub.

  15. The radical Cappuccino - Objective-J (a superset of JavaScript) instead of HTML+CSS+DOM

  16. Mochaui, MooTools UI Library User Interface Library. <300 GitHub stars.

  17. CrossUI - cross-browser JS framework to develop and package the exactly same code and UI into Web Apps, Native Desktop Apps (Windows, OS X, Linux) and Mobile Apps (iOS, Android, Windows Phone, BlackBerry). Open sourced LGPL3. Featured RAD tool (form builder etc.). The UI looks desktop-, not web-oriented. Actively developed, small community. No presence on GitHub.

  18. ZinoUI - simple widgets. The DataTable, for instance, doesn't even support sorting.

  19. Wijmo - good-looking commercial widgets, with old (jQuery UI) widgets open-sourced on GitHub (their development stopped in 2013). Developed by ComponentOne, a division of GrapeCity. See Wijmo Complete vs. Open.

  20. CxJS - commercial JS framework based on React, Babel and webpack offering form elements, form validation, advanced grid control, navigational elements, tooltips, overlays, charts, routing, layout support, themes, culture dependent formatting and more.

CxJS

Widgets - Demo Apps - Examples - GitHub

Full-stack frameworks

  1. SproutCore - developed by Apple for web applications with native performance, handling large data sets on the client. Powers iCloud.com. Not intended for widgets.

  2. Wakanda: aimed at business/enterprise web apps - see What is Wakanda?. Architecture:

  3. Servoy - "a cross platform frontend development and deployment environment for SQL databases". Boasts a "full WYSIWIG (What You See Is What You Get) UI designer for HTML5 with built-in data-binding to back-end services", responsive design, support for HTML6 Web Components, Websockets and mobile platforms. Written in Java and generates JavaScript code using various JavaBeans.

  4. SmartClient/SmartGWT - mobile and cross-browser HTML5 UI components combined with a Java server. Aimed at building powerful business apps - see demos.

  5. Vaadin - full-stack Java/GWT + JavaScript/HTML3 web app framework

  6. Backbase - portal software

  7. Shiny - front-end library on top R, with visualization, layout and control widgets

  8. ZKOSS: Java+jQuery+Bootstrap framework for building enterprise web and mobile apps.

CSS libraries + minimal widgets

These libraries don't implement complex widgets such as tables with sorting/filtering, autocompletes, or trees.

  1. Bootstrap

  2. Foundation for Apps - responsive front-end framework on top of AngularJS; more of a grid/layout/navigation library

  3. UI Kit - similar to Bootstrap, with fewer widgets, but with official off-canvas.

Libraries using HTML Canvas

Using the canvas elements allows for complete control over the UI, and great cross-browser compatibility, but comes at the cost of missing native browser functionality, e.g. page search via Ctrl/Cmd+F.

  1. Zebra - demos

No longer developed as of Dec 2014

  1. Yahoo! User Interface - YUI, launched in 2005, but no longer maintained by the core contributors - see the announcement, which highlights reasons why large UI widget libraries are perceived as walled gardens that developers don't want to be locked into.
  2. echo3, GitHub. Supports writing either server-side Java applications that don't require developer knowledge of HTML, HTTP, or JavaScript, or client-side JavaScript-based applications do not require a server, but can communicate with one via AJAX. Last update: July 2013.
  3. ampleSDK
  4. Simpler widgets livepipe.net
  5. JxLib
  6. rialto
  7. Simple UI kit
  8. Prototype-ui

Other lists

Adding a guideline to the editor in Visual Studio

Visual Studio 2017 / 2019

For anyone looking for an answer for a newer version of Visual Studio, install the Editor Guidelines plugin, then right-click in the editor and select this:

Add guidelines in Visual Studio 2017

MVC 4 Razor File Upload

Clarifying it. Model:

public class ContactUsModel
{
    public string FirstName { get; set; }             
    public string LastName { get; set; }              
    public string Email { get; set; }                 
    public string Phone { get; set; }                 
    public HttpPostedFileBase attachment { get; set; }

Post Action

public virtual ActionResult ContactUs(ContactUsModel Model)
{
 if (Model.attachment.HasFile())
 {
   //save the file

   //Send it as an attachment 
    Attachment messageAttachment = new Attachment(Model.attachment.InputStream,       Model.attachment.FileName);
  }
}

Finally the Extension method for checking the hasFile

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace AtlanticCMS.Web.Common
{
     public static class ExtensionMethods 
     {
         public static bool HasFile(this HttpPostedFileBase file)
         {
             return file != null && file.ContentLength > 0;
         }        
     }
 }

How do I get the "id" after INSERT into MySQL database with Python?

Python DBAPI spec also define 'lastrowid' attribute for cursor object, so...

id = cursor.lastrowid

...should work too, and it's per-connection based obviously.

Get hours difference between two dates in Moment Js

Following code block shows how to calculate the difference in number of days between two dates using MomentJS.

var now = moment(new Date()); //todays date
var end = moment("2015-12-1"); // another date
var duration = moment.duration(now.diff(end));
var days = duration.asDays();
console.log(days)

How to get a URL parameter in Express?

You can do something like req.param('tagId')

How to change DatePicker dialog color for Android 5.0

try this, work for me

Put the two options, colorAccent and android:colorAccent

<style name="AppTheme" parent="@style/Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
   ....
    <item name="android:dialogTheme">@style/AppTheme.DialogTheme</item>
    <item name="android:datePickerDialogTheme">@style/Dialog.Theme</item>
</style>

<style name="AppTheme.DialogTheme" parent="Theme.AppCompat.Light.Dialog">

<!-- Put the two options, colorAccent and android:colorAccent. -->
    <item name="colorAccent">@color/colorPrimary</item>
    <item name="android:colorPrimary">@color/colorPrimary</item>
    <item name="android:colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="android:colorAccent">@color/colorPrimary</item>
 </style>

How to use PrintWriter and File classes in Java?

import java.io.File;
import java.io.PrintWriter;

public class Testing 
{
    public static void main(String[] args) 
    {

        File file = new File("C:/Users/Me/Desktop/directory/file.txt");

        PrintWriter printWriter = null;

        try
        {
            printWriter = new PrintWriter(file);
            printWriter.println("hello");
        }
        catch (FileNotFoundException e)
        {
            e.printStackTrace();
        }
        finally
        {
            if ( printWriter != null ) 
            {
                printWriter.close();
            }
        }
    }
}

How to create loading dialogs in Android?

Today things have changed a little.

Now we avoid use ProgressDialog to show spinning progress:

enter image description here

If you want to put in your app a spinning progress you should use an Activity indicators:

http://developer.android.com/design/building-blocks/progress.html#activity

Chrome Dev Tools - Modify javascript and reload

Yes, just open the "Source" Tab in the dev-tools and navigate to the script you want to change . Make your adjustments directly in the dev tools window and then hit ctrl+s to save the script - know the new js will be used until you refresh the whole page.

Android video streaming example

Your problem is most likely with the video file, not the code. Your video is most likely not "safe for streaming". See where to place videos to stream android for more.

How to convert a string of bytes into an int?

In python 3 you can easily convert a byte string into a list of integers (0..255) by

>>> list(b'y\xcc\xa6\xbb')
[121, 204, 166, 187]

What is href="#" and why is it used?

Unordered lists are often created with the intent of using them as a menu, but an li list item is text. Because the list li item is text, the mouse pointer will not be an arrow, but an "I cursor". Users are accustomed to seeing a pointing finger for a mouse pointer when something is clickable. Using an anchor tag a inside of the li tag causes the mouse pointer to change to a pointing finger. The pointing finger is a lot better for using the list as a menu.

<ul id="menu">
   <li><a href="#">Menu Item 1</a></li>
   <li><a href="#">Menu Item 2</a></li>
   <li><a href="#">Menu Item 3</a></li>
   <li><a href="#">Menu Item 4</a></li>
</ul>

If the list is being used for a menu, and doesn't need a link, then a URL doesn't need to be designated. But the problem is that if you leave out the href attribute, text in the <a> tag is seen as text, and therefore the mouse pointer is back to an I-cursor. The I-cursor might make the user think that the menu item is not clickable. Therefore, you still need an href, but you don't need a link to anywhere.

You could use lots of div or p tags for a menu list, but the mouse pointer would be an I-cursor for them also.

You could use lots of buttons stacked on top of each other for a menu list, but the list seems to be preferable. And that's probably why the href="#" that points to nowhere is used in anchor tags inside of list tags.

You can set the pointer style in CSS, so that is another option. The href="#" to nowhere might just be the lazy way to set some styling.

The operation cannot be completed because the DbContext has been disposed error

You need to remember that IQueryable queries are not actually executed against the data store until you enumerate them.

using (var dataContext = new dataContext())
{

This line of code doesn't actually do anything other than build the SQL statement

    users = dataContext.Users.Where(x => x.AccountID == accountId && x.IsAdmin == false);

.Any() is an operation that enumerates the IQueryable, so the SQL is sent to the data source (through dataContext), and then the .Any() operations is executed against it

    if(users.Any() == false)
    {
        return null;
    }
}

Your "problem" line is reusing the sql built above, and then doing an additional operation (.Select()), which just adds to the query. If you left it here, no exception, except your problem line

return users.Select(x => x.ToInfo()).ToList(); // this line is the problem

calls .ToList(), which enumerates the IQueryable, which causes the SQL to be sent to the datasource through the dataContext that was used in the original LINQ query. Since this dataContext has been disposed, it is no longer valid, and .ToList() throws an exception.

That is the "why it doesn't work". The fix is to move this line of code inside the scope of your dataContext.

How to use it properly is another question with a few arguably correct answers that depend on your application (Forms vs. ASP.net vs. MVC, etc.). The pattern that this implements is the Unit of Work pattern. There is almost no cost to creating a new context object, so the general rule is to create one, do your work, and then dispose of it. In web apps, some people will create a Context per request.

Changing cell color using apache poi

I believe it is because cell.getCellStyle initially returns the default cell style which you then change.

Create styles like this and apply them to cells:

cellStyle = (XSSFCellStyle) cell.getSheet().getWorkbook().createCellStyle();

Although as the previous poster noted try and create styles and reuse them.

There is also some utility class in the XSSF library that will avoid the code I have provided and automatically try and reuse styles. Can't remember the class 0ff hand.

How can I process each letter of text using Javascript?

One possible solution in pure javascript:

for (var x = 0; x < str.length; x++)
{
    var c = str.charAt(x);
    alert(c);
}

Creating a class object in c++

First of all, both cases calls a constructor. If you write

Example *example = new Example();

then you are creating an object, call the constructor and retrieve a pointer to it.

If you write

Example example;

The only difference is that you are getting the object and not a pointer to it. The constructor called in this case is the same as above, the default (no argument) constructor.

As for the singleton question, you must simple invoke your static method by writing:

Example *e = Singleton::getExample();

Sending "User-agent" using Requests library in Python

The user-agent should be specified as a field in the header.

Here is a list of HTTP header fields, and you'd probably be interested in request-specific fields, which includes User-Agent.

If you're using requests v2.13 and newer

The simplest way to do what you want is to create a dictionary and specify your headers directly, like so:

import requests

url = 'SOME URL'

headers = {
    'User-Agent': 'My User Agent 1.0',
    'From': '[email protected]'  # This is another valid field
}

response = requests.get(url, headers=headers)

If you're using requests v2.12.x and older

Older versions of requests clobbered default headers, so you'd want to do the following to preserve default headers and then add your own to them.

import requests

url = 'SOME URL'

# Get a copy of the default headers that requests would use
headers = requests.utils.default_headers()

# Update the headers with your custom ones
# You don't have to worry about case-sensitivity with
# the dictionary keys, because default_headers uses a custom
# CaseInsensitiveDict implementation within requests' source code.
headers.update(
    {
        'User-Agent': 'My User Agent 1.0',
    }
)

response = requests.get(url, headers=headers)

Extracting text OpenCV

Here is an alternative approach that I used to detect the text blocks:

  1. Converted the image to grayscale
  2. Applied threshold (simple binary threshold, with a handpicked value of 150 as the threshold value)
  3. Applied dilation to thicken lines in image, leading to more compact objects and less white space fragments. Used a high value for number of iterations, so dilation is very heavy (13 iterations, also handpicked for optimal results).
  4. Identified contours of objects in resulted image using opencv findContours function.
  5. Drew a bounding box (rectangle) circumscribing each contoured object - each of them frames a block of text.
  6. Optionally discarded areas that are unlikely to be the object you are searching for (e.g. text blocks) given their size, as the algorithm above can also find intersecting or nested objects (like the entire top area for the first card) some of which could be uninteresting for your purposes.

Below is the code written in python with pyopencv, it should easy to port to C++.

import cv2

image = cv2.imread("card.png")
gray = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY) # grayscale
_,thresh = cv2.threshold(gray,150,255,cv2.THRESH_BINARY_INV) # threshold
kernel = cv2.getStructuringElement(cv2.MORPH_CROSS,(3,3))
dilated = cv2.dilate(thresh,kernel,iterations = 13) # dilate
_, contours, hierarchy = cv2.findContours(dilated,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE) # get contours

# for each contour found, draw a rectangle around it on original image
for contour in contours:
    # get rectangle bounding contour
    [x,y,w,h] = cv2.boundingRect(contour)

    # discard areas that are too large
    if h>300 and w>300:
        continue

    # discard areas that are too small
    if h<40 or w<40:
        continue

    # draw rectangle around contour on original image
    cv2.rectangle(image,(x,y),(x+w,y+h),(255,0,255),2)

# write original image with added contours to disk  
cv2.imwrite("contoured.jpg", image) 

The original image is the first image in your post.

After preprocessing (grayscale, threshold and dilate - so after step 3) the image looked like this:

Dilated image

Below is the resulted image ("contoured.jpg" in the last line); the final bounding boxes for the objects in the image look like this:

enter image description here

You can see the text block on the left is detected as a separate block, delimited from its surroundings.

Using the same script with the same parameters (except for thresholding type that was changed for the second image like described below), here are the results for the other 2 cards:

enter image description here

enter image description here

Tuning the parameters

The parameters (threshold value, dilation parameters) were optimized for this image and this task (finding text blocks) and can be adjusted, if needed, for other cards images or other types of objects to be found.

For thresholding (step 2), I used a black threshold. For images where text is lighter than the background, such as the second image in your post, a white threshold should be used, so replace thesholding type with cv2.THRESH_BINARY). For the second image I also used a slightly higher value for the threshold (180). Varying the parameters for the threshold value and the number of iterations for dilation will result in different degrees of sensitivity in delimiting objects in the image.

Finding other object types:

For example, decreasing the dilation to 5 iterations in the first image gives us a more fine delimitation of objects in the image, roughly finding all words in the image (rather than text blocks):

enter image description here

Knowing the rough size of a word, here I discarded areas that were too small (below 20 pixels width or height) or too large (above 100 pixels width or height) to ignore objects that are unlikely to be words, to get the results in the above image.

JavaFX - create custom button with image

You just need to create your own class inherited from parent. Place an ImageView on that, and on the mousedown and mouse up events just change the images of the ImageView.

public class ImageButton extends Parent {

    private static final Image NORMAL_IMAGE = ...;
    private static final Image PRESSED_IMAGE = ...;

    private final ImageView iv;

    public ImageButton() {
        this.iv = new ImageView(NORMAL_IMAGE);
        this.getChildren().add(this.iv);

        this.iv.setOnMousePressed(new EventHandler<MouseEvent>() {

            public void handle(MouseEvent evt) {
                iv.setImage(PRESSED_IMAGE);
            }

        });

        // TODO other event handlers like mouse up

    } 

}

How can I retrieve Id of inserted entity using Entity framework?

The object you're saving should have a correct Id after propagating changes into database.

How to insert data to MySQL having auto incremented primary key?

Check out this post

According to it

No value was specified for the AUTO_INCREMENT column, so MySQL assigned sequence numbers automatically. You can also explicitly assign NULL or 0 to the column to generate sequence numbers.

What is the difference between Swing and AWT?

AWT 1 . AWT occupies more memory space 2 . AWT is platform dependent 3 . AWT require javax.awt package

swings 1 . Swing occupies less memory space 2 . Swing component is platform independent 3 . Swing requires javax.swing package

Sorting an array in C?

I'd like to make some changes: In C, you can use the built in qsort command:

int compare( const void* a, const void* b)
{
   int int_a = * ( (int*) a );
   int int_b = * ( (int*) b );

   // an easy expression for comparing
   return (int_a > int_b) - (int_a < int_b);
}

qsort( a, 6, sizeof(int), compare )

Vue.js redirection to another page

just use:

window.location.href = "http://siwei.me"

Don't use vue-router, otherwise you will be redirected to "http://yoursite.com/#!/http://siwei.me"

my environment: node 6.2.1, vue 1.0.21, Ubuntu.

How to output something in PowerShell

You can use any of these in your scenario since they write to the default streams (output and error). If you were piping output to another commandlet you would want to use Write-Output, which will eventually terminate in Write-Host.

This article describes the different output options: PowerShell O is for Output

Enabling/installing GD extension? --without-gd

In my case (php 5.6, Ubuntu 14.04) the following command worked for me:

sudo apt-get install php5.6-gd

According to php version we need to change the php5.x-gd

Remove columns from DataTable in C#

The question has already been marked as answered, But I guess the question states that the person wants to remove multiple columns from a DataTable.

So for that, here is what I did, when I came across the same problem.

string[] ColumnsToBeDeleted = { "col1", "col2", "col3", "col4" };

foreach (string ColName in ColumnsToBeDeleted)
{
    if (dt.Columns.Contains(ColName))
        dt.Columns.Remove(ColName);
}

How to re-render flatlist?

In this example, to force a re-render, just change the variable machine

const [selected, setSelected] = useState(machine)

useEffect(() => {
    setSelected(machine)
}, [machine])

JSON post to Spring Controller

Try to using application/* instead. And use JSON.maybeJson() to check the data structure in the controller.

What is the difference between Serializable and Externalizable in Java?

The Externalizable interface was not actually provided to optimize the serialization process performance! but to provide means of implementing your own custom processing and offer complete control over the format and contents of the stream for an object and its super types!

Examples of this is the implementation of AMF (ActionScript Message Format) remoting to transfer native action script objects over the network.

JavaScript Promises - reject vs. throw

The difference is ternary operator

  • You can use
return condition ? someData : Promise.reject(new Error('not OK'))
  • You can't use
return condition ? someData  : throw new Error('not OK')

Understanding the set() function

Python's sets (and dictionaries) will iterate and print out in some order, but exactly what that order will be is arbitrary, and not guaranteed to remain the same after additions and removals.

Here's an example of a set changing order after a lot of values are added and then removed:

>>> s = set([1,6,8])
>>> print(s)
{8, 1, 6}
>>> s.update(range(10,100000))
>>> for v in range(10, 100000):
    s.remove(v)
>>> print(s)
{1, 6, 8}

This is implementation dependent though, and so you should not rely upon it.

How can I conditionally require form inputs with AngularJS?

For Angular 2

<input [(ngModel)]='email' [required]='!phone' />
<input [(ngModel)]='phone' [required]='!email' /> 

How to copy a collection from one database to another in MongoDB

In case some heroku users stumble here and like me want to copy some data from staging database to the production database or vice versa here's how you do it very conveniently (N.B. I hope there's no typos in there, can't check it atm., I'll try confirm the validity of the code asap):

to_app="The name of the app you want to migrate data to"
from_app="The name of the app you want to migrate data from"
collection="the collection you want to copy"
mongohq_url=`heroku config:get --app "$to_app" MONGOHQ_URL`
parts=(`echo $mongohq_url | sed "s_mongodb://heroku:__" | sed "s_[@/]_ _g"`)
to_token=${parts[0]}; to_url=${parts[1]}; to_db=${parts[2]}
mongohq_url=`heroku config:get --app "$from_app" MONGOHQ_URL`
parts=(`echo $mongohq_url | sed "s_mongodb://heroku:__" | sed "s_[@/]_ _g"`)
from_token=${parts[0]}; from_url=${parts[1]}; from_db=${parts[2]}
mongodump -h "$from_url" -u heroku -d "$from_db" -p"$from_token" -c "$collection" -o col_dump
mongorestore -h "$prod_url" -u heroku -d "$to_app" -p"$to_token" --dir col_dump/"$col_dump"/$collection".bson -c "$collection"

gcc makefile error: "No rule to make target ..."

This message can mean many things clearly.

In my case it was compiling using multiple threads. One thread needed a dependency that another thread hadn't finished making, causing an error.

Not all builds are threadsafe, so consider a slow build with one thread if your build passes other tests such as the ones listed above.

Correct way to try/except using Python requests module?

Exception object also contains original response e.response, that could be useful if need to see error body in response from the server. For example:

try:
    r = requests.post('somerestapi.com/post-here', data={'birthday': '9/9/3999'})
    r.raise_for_status()
except requests.exceptions.HTTPError as e:
    print (e.response.text)

Pressing Ctrl + A in Selenium WebDriver

WebDriver driver = new FirefoxDriver();

Actions action = new Actions(driver); 

action.keyDown(Keys.CONTROL).sendKeys("a").keyUp(Keys.CONTROL).perform();

This method removes the extra call ( String.ValueOf() ) to convert unicode to string.

Check if a column contains text using SQL

Suppose STUDENTID contains some characters or numbers that you already know i.e. 'searchstring' then below query will work for you.

You could try this:

select * from STUDENTS where CHARINDEX('searchstring',STUDENTID)>0

I think this one is the fastest and easiest one.

Maven: repository element was not specified in the POM inside distributionManagement?

You can also override the deployment repository on the command line: -Darguments=-DaltDeploymentRepository=myreposid::default::http://my/url/releases

How to replace � in a string

That's the Unicode Replacement Character, \uFFFD. (info)

Something like this should work:

String strImport = "For some reason my ?double quotes? were lost.";
strImport = strImport.replaceAll("\uFFFD", "\"");

Convert list into a pandas data frame

You need convert list to numpy array and then reshape:

df = pd.DataFrame(np.array(my_list).reshape(3,3), columns = list("abc"))
print (df)
   a  b  c
0  1  2  3
1  4  5  6
2  7  8  9

Running Composer returns: "Could not open input file: composer.phar"

To solve this issue the first thing you need to do is to get the last version of composer :

curl -sS https://getcomposer.org/installer | php

I recommend you to move the composer.phar file to a global “bin” directoy, in my case (OS X) the path is:

mv composer.phar /usr/local/bin/composer.phar

than you need to create an alias file for an easy access

alias composer='/usr/local/bin/composer.phar'

If everything is ok, now it is time to verify our Composer version:

composer --version

Let's make composer great again.

if A vs if A is not None:

A lot of functions return None if there are no appropriate results. For example, an SQLAlchemy query's .first() method returns None if there were no rows in the result. Suppose you were selecting a value that might return 0 and need to know whether it's actually 0 or whether the query had no results at all.

A common idiom is to give a function or method's optional argument the default value of None, and then to test that value being None to see if it was specified. For example:

def spam(eggs=None):
    if eggs is None:
        eggs = retrievefromconfigfile()

compare that to:

def spam(eggs=None):
    if not eggs:
        eggs = retrievefromconfigfile()

In the latter, what happens if you call spam(0) or spam([])? The function would (incorrectly) detect that you hadn't passed in a value for eggs and would compute a default value for you. That's probably not what you want.

Or imagine a method like "return the list of transactions for a given account". If the account does not exist, it might return None. This is different than returning an empty list (which would mean "this account exists but has not recorded transactions).

Finally, back to database stuff. There's a big difference between NULL and an empty string. An empty string typically says "there's a value here, and that value is nothing at all". NULL says "this value hasn't been entered."

In each of those cases, you'd want to use if A is None. You're checking for a specific value - None - not just "any value that happens to cast to False".

How to check if a column exists in a SQL Server table?

if exists (
  select * 
  from INFORMATION_SCHEMA.COLUMNS 
  where TABLE_NAME = '<table_name>' 
  and COLUMN_NAME = '<column_name>'
) begin
  print 'Column you have specified exists'
end else begin
  print 'Column does not exist'
end

Mean filter for smoothing images in Matlab

h = fspecial('average', n);
filter2(h, img);

See doc fspecial: h = fspecial('average', n) returns an averaging filter. n is a 1-by-2 vector specifying the number of rows and columns in h.

How to copy the first few lines of a giant file, and add a line of text at the end of it using some Linux commands?

I am assuming what you are trying to achieve is to insert a line after the first few lines of of a textfile.

head -n10 file.txt >> newfile.txt
echo "your line >> newfile.txt
tail -n +10 file.txt >> newfile.txt

If you don't want to rest of the lines from the file, just skip the tail part.

Setting the filter to an OpenFileDialog to allow the typical image formats?

This is extreme, but I built a dynamic, database-driven filter using a 2 column database table named FILE_TYPES, with field names EXTENSION and DOCTYPE:

---------------------------------
| EXTENSION  |  DOCTYPE         |
---------------------------------
|   .doc     |  Document        |
|   .docx    |  Document        |
|   .pdf     |  Document        |
|   ...      |  ...             |
|   .bmp     |  Image           |
|   .jpg     |  Image           |
|   ...      |  ...             |
---------------------------------

Obviously I had many different types and extensions, but I'm simplifying it for this example. Here is my function:

    private static string GetUploadFilter()
    {
        // Desired format:
        // "Document files (*.doc, *.docx, *.pdf)|*.doc;*.docx;*.pdf|"
        // "Image files (*.bmp, *.jpg)|*.bmp;*.jpg|"

        string filter = String.Empty;
        string nameFilter = String.Empty;
        string extFilter = String.Empty;

        // Used to get extensions
        DataTable dt = new DataTable();
        dt = DataLayer.Get_DataTable("SELECT * FROM FILE_TYPES ORDER BY EXTENSION");

        // Used to cycle through doctype groupings ("Images", "Documents", etc.)
        DataTable dtDocTypes = new DataTable();
        dtDocTypes = DataLayer.Get_DataTable("SELECT DISTINCT DOCTYPE FROM FILE_TYPES ORDER BY DOCTYPE");

        // For each doctype grouping...
        foreach (DataRow drDocType in dtDocTypes.Rows)
        {
            nameFilter = drDocType["DOCTYPE"].ToString() + " files (";

            // ... add its associated extensions
            foreach (DataRow dr in dt.Rows)
            {
                if (dr["DOCTYPE"].ToString() == drDocType["DOCTYPE"].ToString())
                {
                    nameFilter += "*" + dr["EXTENSION"].ToString() + ", ";
                    extFilter += "*" + dr["EXTENSION"].ToString() + ";";
                }                    
            }

            // Remove endings put in place in case there was another to add, and end them with pipe characters:
            nameFilter = nameFilter.TrimEnd(' ').TrimEnd(',');
            nameFilter += ")|";
            extFilter = extFilter.TrimEnd(';');
            extFilter += "|";

            // Add the name and its extensions to our main filter
            filter += nameFilter + extFilter;

            extFilter = ""; // clear it for next round; nameFilter will be reset to the next DOCTYPE on next pass
        }

        filter = filter.TrimEnd('|');
        return filter;
    }

    private void UploadFile(string fileType, object sender)
    {            
        Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
        string filter = GetUploadFilter();
        dlg.Filter = filter;

        if (dlg.ShowDialog().Value == true)
        {
            string fileName = dlg.FileName;

            System.IO.FileStream fs = System.IO.File.OpenRead(fileName);
            byte[] array = new byte[fs.Length];

            // This will give you just the filename
            fileName = fileName.Split('\\')[fileName.Split('\\').Length - 1];
            ...

Should yield a filter that looks like this:

enter image description here

phpinfo() - is there an easy way for seeing it?

Use the command line.

touch /var/www/project1/html/phpinfo.php && echo '<?php phpinfo(); ?>' >> /var/www/project1/html/phpinfo.php && firefox --url localhost/project1/phpinfo.php

Something like that? Idk!

Eclipse cannot load SWT libraries

I came across this error when tried to start 32-bit build of Eclipse under 64-bit linux. The problem was solved after installing ia32-libs package.

How to invoke a Linux shell command from Java

exec does not execute a command in your shell

try

Process p = Runtime.getRuntime().exec(new String[]{"csh","-c","cat /home/narek/pk.txt"});

instead.

EDIT:: I don't have csh on my system so I used bash instead. The following worked for me

Process p = Runtime.getRuntime().exec(new String[]{"bash","-c","ls /home/XXX"});

Simple and clean way to convert JSON string to Object in Swift

You can use swift.quicktype.io for converting JSON to either struct or class. Even you can mention version of swift to genrate code.

Example JSON:

{
  "message": "Hello, World!"
}

Generated code:

import Foundation

typealias Sample = OtherSample

struct OtherSample: Codable {
    let message: String
}

// Serialization extensions

extension OtherSample {
    static func from(json: String, using encoding: String.Encoding = .utf8) -> OtherSample? {
        guard let data = json.data(using: encoding) else { return nil }
        return OtherSample.from(data: data)
    }

    static func from(data: Data) -> OtherSample? {
        let decoder = JSONDecoder()
        return try? decoder.decode(OtherSample.self, from: data)
    }

    var jsonData: Data? {
        let encoder = JSONEncoder()
        return try? encoder.encode(self)
    }

    var jsonString: String? {
        guard let data = self.jsonData else { return nil }
        return String(data: data, encoding: .utf8)
    }
}

extension OtherSample {
    enum CodingKeys: String, CodingKey {
        case message
    }
}

Input type for HTML form for integer

This might help:

<input type="number" step="1" pattern="\d+" />

step is for convenience (and could be set to another integer), but pattern does some actual enforcing.

Note that since pattern matches the whole expression, it wasn't necessary to express it as ^\d+$.

Even with this outwardly tight regular expression, Chrome and Firefox's implementations, interestingly allow for e here (presumably for scientific notation) as well as - for negative numbers, and Chrome also allows for . whereas Firefox is tighter in rejecting unless the . is followed by 0's only. (Firefox marks the field as red upon the input losing focus whereas Chrome doesn't let you input disallowed values in the first place.)

Since, as observed by others, one should always validate on the server (or on the client too, if using the value locally on the client or wishing to prevent the user from a roundtrip to the server).

How to add a footer to the UITableView?

If you don't prefer the sticky bottom effect i would put it in viewDidLoad() https://stackoverflow.com/a/38176479/4127670

How do I remove a MySQL database?

For Visual Studio, in the package manager console:

 drop-database

Checking if a variable is defined?

The correct syntax for the above statement is:

if (defined?(var)).nil? # will now return true or false
 print "var is not defined\n".color(:red)
else
 print "var is defined\n".color(:green)
end

substituting (var) with your variable. This syntax will return a true/false value for evaluation in the if statement.

How to generate all permutations of a list?

for Python we can use itertools and import both permutations and combinations to solve your problem

from itertools import product, permutations
A = ([1,2,3])
print (list(permutations(sorted(A),2)))

gradlew: Permission Denied

chmod +x gradlew

Just run the above comment. that's all enjoy your coding...

MySQL Removing Some Foreign keys

As explained here, seems the foreign key constraint has to be dropped by constraint name and not the index name.

The syntax is:

ALTER TABLE footable DROP FOREIGN KEY fooconstraint;

Mapping composite keys using EF code first

For Mapping Composite primary key using Entity framework we can use two approaches.

1) By Overriding the OnModelCreating() Method

For ex: I have the model class named VehicleFeature as shown below.

public class VehicleFeature
{
    public int VehicleId { get; set; }
    public int FeatureId{get;set;}
    public Vehicle Vehicle{get;set;}
    public Feature Feature{get;set;}
}

The Code in my DBContext would be like ,

public class VegaDbContext : DbContext
{
    public DbSet<Make> Makes{get;set;}

    public DbSet<Feature> Features{get;set;}
    public VegaDbContext(DbContextOptions<VegaDbContext> options):base(options)        
    {           

    }
    // we override the OnModelCreating method here.
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<VehicleFeature>().HasKey(vf=> new {vf.VehicleId, vf.FeatureId});
    }
}

2) By Data Annotations.

public class VehicleFeature
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]  
    [Key]
    public int VehicleId { get; set; }
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]   
    [Key]
    public int FeatureId{get;set;}
    public Vehicle Vehicle{get;set;}
    public Feature Feature{get;set;}
}

Please refer the below links for the more information.

1) https://msdn.microsoft.com/en-us/library/jj591617(v=vs.113).aspx

2) How to add a composite unique key using EF 6 Fluent Api?

The order of keys in dictionaries

Although the order does not matter as the dictionary is hashmap. It depends on the order how it is pushed in:

s = 'abbc'
a = 'cbab'

def load_dict(s):
    dict_tmp = {}
    for ch in s:
        if ch in dict_tmp.keys():
            dict_tmp[ch]+=1
        else:
            dict_tmp[ch] = 1
    return dict_tmp

dict_a = load_dict(a)
dict_s = load_dict(s)
print('for string %s, the keys are %s'%(s, dict_s.keys()))
print('for string %s, the keys are %s'%(a, dict_a.keys()))

output:
for string abbc, the keys are dict_keys(['a', 'b', 'c'])
for string cbab, the keys are dict_keys(['c', 'b', 'a'])

Could not open input file: artisan

If you project is at /home/forge/laravel-project/

You can properly execute your artisan like this

php /home/forge/laravel-project/artisan ...

How can we print line numbers to the log in java

From Angsuman Chakraborty (archived) :

/** Get the current line number.
 * @return int - Current line number.
 */
public static int getLineNumber() {
    return Thread.currentThread().getStackTrace()[2].getLineNumber();
}

Scala Doubles, and Precision

You can use scala.math.BigDecimal:

BigDecimal(1.23456789).setScale(2, BigDecimal.RoundingMode.HALF_UP).toDouble

There are a number of other rounding modes, which unfortunately aren't very well documented at present (although their Java equivalents are).

Anybody knows any knowledge base open source?

How about one of the many wikis?

Kenny: I've used FlexWiki & ScrewTurn (abandoned).

someone else with RepPower to edit my post added this.
Wikipedia is powered by MediaWiki.

Histogram with Logarithmic Scale and custom breaks

Here's a pretty ggplot2 solution:

library(ggplot2)
library(scales)  # makes pretty labels on the x-axis

breaks=c(0,1,2,3,4,5,25)

ggplot(mydata,aes(x = V3)) + 
  geom_histogram(breaks = log10(breaks)) + 
  scale_x_log10(
    breaks = breaks,
    labels = scales::trans_format("log10", scales::math_format(10^.x))
  )

Note that to set the breaks in geom_histogram, they had to be transformed to work with scale_x_log10