Programs & Examples On #Readlines

This tag refers to the `readlines` method available on file objects in Python.

Break string into list of characters in Python

You can do this using list:

new_list = list(fL)

Be aware that any spaces in the line will be included in this list, to the best of my knowledge.

How to read a file without newlines?

You can read the whole file and split lines using str.splitlines:

temp = file.read().splitlines()

Or you can strip the newline by hand:

temp = [line[:-1] for line in file]

Note: this last solution only works if the file ends with a newline, otherwise the last line will lose a character.

This assumption is true in most cases (especially for files created by text editors, which often do add an ending newline anyway).

If you want to avoid this you can add a newline at the end of file:

with open(the_file, 'r+') as f:
    f.seek(-1, 2)  # go at the end of the file
    if f.read(1) != '\n':
        # add missing newline if not already present
        f.write('\n')
        f.flush()
        f.seek(0)
    lines = [line[:-1] for line in f]

Or a simpler alternative is to strip the newline instead:

[line.rstrip('\n') for line in file]

Or even, although pretty unreadable:

[line[:-(line[-1] == '\n') or len(line)+1] for line in file]

Which exploits the fact that the return value of or isn't a boolean, but the object that was evaluated true or false.


The readlines method is actually equivalent to:

def readlines(self):
    lines = []
    for line in iter(self.readline, ''):
        lines.append(line)
    return lines

# or equivalently

def readlines(self):
    lines = []
    while True:
        line = self.readline()
        if not line:
            break
        lines.append(line)
    return lines

Since readline() keeps the newline also readlines() keeps it.

Note: for symmetry to readlines() the writelines() method does not add ending newlines, so f2.writelines(f.readlines()) produces an exact copy of f in f2.

Python readlines() usage and efficient practice for reading

Read line by line, not the whole file:

for line in open(file_name, 'rb'):
    # process line here

Even better use with for automatically closing the file:

with open(file_name, 'rb') as f:
    for line in f:
        # process line here

The above will read the file object using an iterator, one line at a time.

How to get length of a list of lists in python

The method len() returns the number of elements in the list.

 list1, list2 = [123, 'xyz', 'zara'], [456, 'abc']
    print "First list length : ", len(list1)
    print "Second list length : ", len(list2)

When we run above program, it produces the following result -

First list length : 3 Second list length : 2

How to read a file line-by-line into a list?

Having a Text file content:

line 1
line 2
line 3

We can use this Python script in the same directory of the txt above

>>> with open("myfile.txt", encoding="utf-8") as file:
...     x = [l.rstrip("\n") for l in file]
>>> x
['line 1','line 2','line 3']

Using append:

x = []
with open("myfile.txt") as file:
    for l in file:
        x.append(l.strip())

Or:

>>> x = open("myfile.txt").read().splitlines()
>>> x
['line 1', 'line 2', 'line 3']

Or:

>>> x = open("myfile.txt").readlines()
>>> x
['linea 1\n', 'line 2\n', 'line 3\n']

Or:

def print_output(lines_in_textfile):
    print("lines_in_textfile =", lines_in_textfile)

y = [x.rstrip() for x in open("001.txt")]
print_output(y)

with open('001.txt', 'r', encoding='utf-8') as file:
    file = file.read().splitlines()
    print_output(file)

with open('001.txt', 'r', encoding='utf-8') as file:
    file = [x.rstrip("\n") for x in file]
    print_output(file)

output:

lines_in_textfile = ['line 1', 'line 2', 'line 3']
lines_in_textfile = ['line 1', 'line 2', 'line 3']
lines_in_textfile = ['line 1', 'line 2', 'line 3']

How to change Visual Studio 2012,2013 or 2015 License Key?

The ISO is probably pre-pidded. You'll need to delete the key from the setup files. It should then ask you for a key during installation.

Center align a column in twitter bootstrap

If you cannot put 1 column, you can simply put 2 column in the middle... (I am just combining answers) For Bootstrap 3

<div class="row">
   <div class="col-lg-5 ">5 columns left</div>
   <div class="col-lg-2 col-centered">2 column middle</div>
   <div class="col-lg-5">5 columns right</div>
</div>

Even, you can text centered column by adding this to style:

.col-centered{
  display: block;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

Additionally, there is another solution here

How to launch PowerShell (not a script) from the command line

If you go to C:\Windows\system32\Windowspowershell\v1.0 (and C:\Windows\syswow64\Windowspowershell\v1.0 on x64 machines) in Windows Explorer and double-click powershell.exe you will see that it opens PowerShell with a black background. The PowerShell console shows up as blue when opened from the start menu because the console properties for shortcuts to powershell.exe can be set independently from the default properties.

To set the default options, font, colors and layout, open a PowerShell console, type Alt-Space, and select the Defaults menu option.

Running start powershell from cmd.exe should start a new console with your default settings.

Use Fieldset Legend with bootstrap

I had this problem and I solved with this way:

fieldset.scheduler-border {
    border: solid 1px #DDD !important;
    padding: 0 10px 10px 10px;
    border-bottom: none;
}

legend.scheduler-border {
    width: auto !important;
    border: none;
    font-size: 14px;
}

What is mapDispatchToProps?

It's basically a shorthand. So instead of having to write:

this.props.dispatch(toggleTodo(id));

You would use mapDispatchToProps as shown in your example code, and then elsewhere write:

this.props.onTodoClick(id);

or more likely in this case, you'd have that as the event handler:

<MyComponent onClick={this.props.onTodoClick} />

There's a helpful video by Dan Abramov on this here: https://egghead.io/lessons/javascript-redux-generating-containers-with-connect-from-react-redux-visibletodolist

How to force cp to overwrite without confirmation

you can use this command as well:

cp -ru /zzz/zzz/* /xxx/xxx

it would update your existing file with the newer one though.

How to quickly drop a user with existing privileges

Here's what's finally worked for me :

REVOKE ALL PRIVILEGES ON ALL TABLES IN SCHEMA myschem FROM user_mike;
REVOKE ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA myschem FROM user_mike;
REVOKE ALL PRIVILEGES ON ALL FUNCTIONS IN SCHEMA myschem FROM user_mike;
REVOKE ALL PRIVILEGES ON SCHEMA myschem FROM user_mike;
ALTER DEFAULT PRIVILEGES IN SCHEMA myschem REVOKE ALL ON SEQUENCES FROM user_mike;
ALTER DEFAULT PRIVILEGES IN SCHEMA myschem REVOKE ALL ON TABLES FROM user_mike;
ALTER DEFAULT PRIVILEGES IN SCHEMA myschem REVOKE ALL ON FUNCTIONS FROM user_mike;
REVOKE USAGE ON SCHEMA myschem FROM user_mike;
REASSIGN OWNED BY user_mike TO masteruser;
DROP USER user_mike ;

Regex match digits, comma and semicolon?

boolean foundMatch = Pattern.matches("[0-9,;]+", "131;23,87");

Uncaught SoapFault exception: [HTTP] Error Fetching http headers

If this is a Magento related problem, you should turn off automatic re-indexing as this could be causing the socket to timeout (or expire). You can turn it back on once the script has finished its tasks. Increasing the default socket timeout in php.ini is also a good idea.

How to add a new row to an empty numpy array

The way to "start" the array that you want is:

arr = np.empty((0,3), int)

Which is an empty array but it has the proper dimensionality.

>>> arr
array([], shape=(0, 3), dtype=int64)

Then be sure to append along axis 0:

arr = np.append(arr, np.array([[1,2,3]]), axis=0)
arr = np.append(arr, np.array([[4,5,6]]), axis=0)

But, @jonrsharpe is right. In fact, if you're going to be appending in a loop, it would be much faster to append to a list as in your first example, then convert to a numpy array at the end, since you're really not using numpy as intended during the loop:

In [210]: %%timeit
   .....: l = []
   .....: for i in xrange(1000):
   .....:     l.append([3*i+1,3*i+2,3*i+3])
   .....: l = np.asarray(l)
   .....: 
1000 loops, best of 3: 1.18 ms per loop

In [211]: %%timeit
   .....: a = np.empty((0,3), int)
   .....: for i in xrange(1000):
   .....:     a = np.append(a, 3*i+np.array([[1,2,3]]), 0)
   .....: 
100 loops, best of 3: 18.5 ms per loop

In [214]: np.allclose(a, l)
Out[214]: True

The numpythonic way to do it depends on your application, but it would be more like:

In [220]: timeit n = np.arange(1,3001).reshape(1000,3)
100000 loops, best of 3: 5.93 µs per loop

In [221]: np.allclose(a, n)
Out[221]: True

Difference between Encapsulation and Abstraction

There is a great article that touches on differences between Abstraction, Encapsulation and Information hiding in depth: http://www.tonymarston.co.uk/php-mysql/abstraction.txt

Here is the conclusion from the article:

Abstraction, information hiding, and encapsulation are very different, but highly-related, concepts. One could argue that abstraction is a technique that helps us identify which specific information should be visible, and which information should be hidden. Encapsulation is then the technique for packaging the information in such a way as to hide what should be hidden, and make visible what is intended to be visible.

Git - Won't add files?

Silly solution from me, but I thought that it wasn't adding and pushing new files because github.com wasn't showing the files I had just pushed. I had forgotten that the files I added were on a different branch. The files had push just fine. I had to switch from my master branch to the new branch in github to see them. Lost a few minutes on that one :)

Remove Last Comma from a string

The greatly upvoted answer removes not only the final comma, but also any spaces that follow. But removing those following spaces was not what was part of the original problem. So:

let str = 'abc,def,ghi, ';
let str2 = str.replace(/,(?=\s*$)/, '');
alert("'" + str2 + "'");
'abc,def,ghi '

https://jsfiddle.net/dc8moa3k/

can't load package: package .: no buildable Go source files

I had this exact error code and after checking my repository discovered that there were no go files but actually just more directories. So it was more of a red herring than an error for me.

I would recommend doing

go env

and making sure that everything is as it should be, check your environment variables in your OS and check to make sure your shell (bash or w/e ) isn't compromising it via something like a .bash_profile or .bashrc file. good luck.

How to change the integrated terminal in visual studio code or VSCode

I was successful via settings > Terminal > Integrated > Shell: Linux

from there I edited the path of the shell to be /bin/zsh from the default /bin/bash

  • there are also options for OSX and Windows as well

screencap of vs settings view

@charlieParker - here's what i'm seeing for available commands in the command pallette

enter image description here

Xcode warning: "Multiple build commands for output file"

React-Native users. goto file -> workspace settings -> build system -> change it to legacy build system. and it should build fine now. React-Native isn't compatible with the new file system yet.

Hibernate SessionFactory vs. JPA EntityManagerFactory

I want to add on this that you can also get Hibernate's session by calling getDelegate() method from EntityManager.

ex:

Session session = (Session) entityManager.getDelegate();

Adding blank spaces to layout

The previous answers didn't work in my case. However, creating an empty item in the menu does.

<menu xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android">
  ...
  <item />
  ...
</menu>

Paramiko's SSHClient with SFTP

paramiko.SFTPClient

Sample Usage:

import paramiko
paramiko.util.log_to_file("paramiko.log")

# Open a transport
host,port = "example.com",22
transport = paramiko.Transport((host,port))

# Auth    
username,password = "bar","foo"
transport.connect(None,username,password)

# Go!    
sftp = paramiko.SFTPClient.from_transport(transport)

# Download
filepath = "/etc/passwd"
localpath = "/home/remotepasswd"
sftp.get(filepath,localpath)

# Upload
filepath = "/home/foo.jpg"
localpath = "/home/pony.jpg"
sftp.put(localpath,filepath)

# Close
if sftp: sftp.close()
if transport: transport.close()

How do I list all loaded assemblies?

Using Visual Studio

  1. Attach a debugger to the process (e.g. start with debugging or Debug > Attach to process)
  2. While debugging, show the Modules window (Debug > Windows > Modules)

This gives details about each assembly, app domain and has a few options to load symbols (i.e. pdb files that contain debug information).

enter image description here

Using Process Explorer

If you want an external tool you can use the Process Explorer (freeware, published by Microsoft)

Click on a process and it will show a list with all the assemblies used. The tool is pretty good as it shows other information such as file handles etc.

Programmatically

Check this SO question that explains how to do it.

What is the difference between \r and \n?

In short \r has ASCII value 13 (CR) and \n has ASCII value 10 (LF). Mac uses CR as line delimiter (at least, it did before, I am not sure for modern macs), *nix uses LF and Windows uses both (CRLF).

How to format a date using ng-model?

Angularjs ui bootstrap you can use angularjs ui bootstrap, it provides date validation also

<input type="text"  class="form-control" 
datepicker-popup="{{format}}" ng-model="dt" is-open="opened" 
min-date="minDate" max-date="'2015-06-22'"  datepickeroptions="dateOptions"
date-disabled="disabled(date, mode)" ng-required="true"> 



in controller can specify whatever format you want to display the date as datefilter

$scope.formats = ['dd-MMMM-yyyy', 'yyyy/MM/dd', 'dd.MM.yyyy', 'shortDate'];

Trouble setting up git with my GitHub Account error: could not lock config file

Just use the following command if you wanna set configuration in system level:

$ sudo git config --system user.name "my_name"

Batch file to copy directories recursively

You may write a recursive algorithm in Batch that gives you exact control of what you do in every nested subdirectory:

@echo off
call :treeProcess
goto :eof

:treeProcess
rem Do whatever you want here over the files of this subdir, for example:
copy *.* C:\dest\dir
for /D %%d in (*) do (
    cd %%d
    call :treeProcess
    cd ..
)
exit /b

Windows Batch File Looping Through Directories to Process Files?

Removing u in list

u'AB' is just a text representation of the corresponding Unicode string. Here're several methods that create exactly the same Unicode string:

L = [u'AB', u'\x41\x42', u'\u0041\u0042', unichr(65) + unichr(66)]
print u", ".join(L)

Output

AB, AB, AB, AB

There is no u'' in memory. It is just the way to represent the unicode object in Python 2 (how you would write the Unicode string literal in a Python source code). By default print L is equivalent to print "[%s]" % ", ".join(map(repr, L)) i.e., repr() function is called for each list item:

print L
print "[%s]" % ", ".join(map(repr, L))

Output

[u'AB', u'AB', u'AB', u'AB']
[u'AB', u'AB', u'AB', u'AB']

If you are working in a REPL then a customizable sys.displayhook is used that calls repr() on each object by default:

>>> L = [u'AB', u'\x41\x42', u'\u0041\u0042', unichr(65) + unichr(66)]
>>> L
[u'AB', u'AB', u'AB', u'AB']
>>> ", ".join(L)
u'AB, AB, AB, AB'
>>> print ", ".join(L)
AB, AB, AB, AB

Don't encode to bytes. Print unicode directly.


In your specific case, I would create a Python list and use json.dumps() to serialize it instead of using string formatting to create JSON text:

#!/usr/bin/env python2
import json
# ...
test = [dict(email=player.email, gem=player.gem)
        for player in players]
print test
print json.dumps(test)

Output

[{'email': u'[email protected]', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test1', 'gem': 0}]
[{"email": "[email protected]", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test1", "gem": 0}]

Why don't self-closing script elements work?

Unlike XML and XHTML, HTML has no knowledge of the self-closing syntax. Browsers that interpret XHTML as HTML don't know that the / character indicates that the tag should be self-closing; instead they interpret it like an empty attribute and the parser still thinks the tag is 'open'.

Just as <script defer> is treated as <script defer="defer">, <script /> is treated as <script /="/">.

Random numbers with Math.random() in Java

If min = 5, and max = 10, and Math.random() returns (almost) 1.0, the generated number will be (almost) 15, which is clearly more than the chosen max.

Relatedly, this is why every random number API should let you specify min and max explicitly. You shouldn't have to write error-prone maths that are tangential to your problem domain.

Multiple simultaneous downloads using Wget?

They always say it depends but when it comes to mirroring a website The best exists httrack. It is super fast and easy to work. The only downside is it's so called support forum but you can find your way using official documentation. It has both GUI and CLI interface and it Supports cookies just read the docs This is the best.(Be cureful with this tool you can download the whole web on your harddrive)

httrack -c8 [url]

By default maximum number of simultaneous connections limited to 8 to avoid server overload

Failed to resolve: com.android.support:appcompat-v7:27.+ (Dependency Error)

If you are using Android Studio 3.0 or above make sure your project build.gradle should have content similar to-

buildscript {                 
    repositories {
        google()
        jcenter()
    }
    dependencies {            
        classpath 'com.android.tools.build:gradle:3.0.1'

    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

Note- position really matters add google() before jcenter()

And for below Android Studio 3.0 and starting from support libraries 26.+ your project build.gradle must look like this-

allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

check these links below for more details-

1- Building Android Apps

2- Add Build Dependencies

3- Configure Your Build

Show two digits after decimal point in c++

The easiest way to do this, is using cstdio's printf. Actually, i'm surprised that anyone mentioned printf! anyway, you need to include the library, like this...

#include<cstdio>

int main() {
    double total;
    cin>>total;
    printf("%.2f\n", total);
}

This will print the value of "total" (that's what %, and then ,total does) with 2 floating points (that's what .2f does). And the \n at the end, is just the end of line, and this works with UVa's judge online compiler options, that is:

g++ -lm -lcrypt -O2 -pipe -DONLINE_JUDGE filename.cpp

the code you are trying to run will not run with this compiler options...

Android Studio how to run gradle sync manually?

Shortcut (Ubuntu, Windows):

Ctrl + F5

Will sync the project with Gradle files.

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

My issue was that my method was missing the @RequestBody annotation. After adding the annotation I no longer received the 404 exception.

Visual Studio Code cannot detect installed git

  1. Make sure git is enabled (File --> Preferences --> Git Enabled) as other have mentioned.
  2. Make sure Gits installed and in the PATH (with the correct location, by default: C:\Program Files\Git\cmd) - PATH on system variables btw
  3. Change default terminal, Powershell can be a bit funny, I recommend Git BASH but cmd is fine, this can be done by selecting the terminal dropdown and selecting 'set default shell' then creating a new terminal with the + button.
  4. Restarting VS Code, sometimes Reboot if that fails.

Hope that helped, and last but not least, it's 'git' not 'Git'/'gat'. :)

phpinfo() is not working on my CentOS server

You need to update your Apache configuration to make sure it's outputting php as the type text/HTML.

The below code should work, but some configurations are different.

AddHandler php5-script .php
AddType text/html .php

How to define partitioning of DataFrame?

So to start with some kind of answer : ) - You can't

I am not an expert, but as far as I understand DataFrames, they are not equal to rdd and DataFrame has no such thing as Partitioner.

Generally DataFrame's idea is to provide another level of abstraction that handles such problems itself. The queries on DataFrame are translated into logical plan that is further translated to operations on RDDs. The partitioning you suggested will probably be applied automatically or at least should be.

If you don't trust SparkSQL that it will provide some kind of optimal job, you can always transform DataFrame to RDD[Row] as suggested in of the comments.

How to fix curl: (60) SSL certificate: Invalid certificate chain

Using the Safari browser (not Chrome, Firefox or Opera) on Mac OS X 10.9 (Mavericks) visit https://registry.npmjs.org

Screenshot of Safari showing certificate error

Click the Show certificate button and then check the checkbox labelled Always trust. Then click Continue and enter your password if required.

Always trust checkbox

Curl should now work with that URL correctly.

jQuery convert line breaks to br (nl2br equivalent)

to improve @Luca Filosofi's accepted answer,

if needed, changing the beginning clause of this regex to be /([^>[\s]?\r\n]?) will also ingore the cases where the newline comes after a tag AND some whitespace, instead of just a tag immediately followed by a newline

Create file path from variables

Yes there is such a built-in function: os.path.join.

>>> import os.path
>>> os.path.join('/my/root/directory', 'in', 'here')
'/my/root/directory/in/here'

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

For non-InnoDB tables you could also use the information schema tables:

http://dev.mysql.com/doc/refman/5.1/en/tables-table.html

What are forward declarations in C++?

When the compiler sees add(3, 4) it needs to know what that means. With the forward declaration you basically tell the compiler that add is a function that takes two ints and returns an int. This is important information for the compiler becaus it needs to put 4 and 5 in the correct representation onto the stack and needs to know what type the thing returned by add is.

At that time, the compiler is not worried about the actual implementation of add, ie where it is (or if there is even one) and if it compiles. That comes into view later, after compiling the source files when the linker is invoked.

jQuery remove options from select

When I did just a remove the option remained in the ddl on the view, but was gone in the html (if u inspect the page)

$("#ddlSelectList option[value='2']").remove(); //removes the option with value = 2
$('#ddlSelectList').val('').trigger('chosen:updated'); //refreshes the drop down list

Display HTML form values in same page after submit using Ajax

One more way to do it (if you use form), note that input type is button

<input type="button" onclick="showMessage()" value="submit" />

Complete code is:

<!DOCTYPE html>
<html>
<head>
    <title>HTML JavaScript output on same page</title>
    <script type="text/JavaScript">
        function showMessage(){
            var message = document.getElementById("message").value;
            display_message.innerHTML= message;
        }
    </script>
</head>
<body>
<form>
Enter message: <input type="text" id = "message">
<input type="button" onclick="showMessage()" value="submit" />
</form>
<p> Message is: <span id = "display_message"></span> </p>
</body>
</html>

But you can do it even without form:

<!DOCTYPE html>
<html>
<head>
    <title>HTML JavaScript output on same page</title>
    <script type="text/JavaScript">
        function showMessage(){
            var message = document.getElementById("message").value;
            display_message.innerHTML= message;
        }
    </script>
</head>
<body>
Enter message: <input type="text" id = "message">
<input type="submit" onclick="showMessage()" value="submit" />
<p> Message is: <span id = "display_message"></span> </p>
</body>
</html>

Here you can use either submit or button:

<input type="submit" onclick="showMessage()" value="submit" />

No need to set

return false;

from JavaScript function for neither of those two examples.

How to set ChartJS Y axis title?

Consider using a the transform: rotate(-90deg) style on an element. See http://www.w3schools.com/cssref/css3_pr_transform.asp

Example, In your css

.verticaltext_content {
  position: relative;
  transform: rotate(-90deg);
  right:90px;   //These three positions need adjusting
  bottom:150px; //based on your actual chart size
  width:200px;
}

Add a space fudge factor to the Y Axis scale so the text has room to render in your javascript.

scaleLabel: "      <%=value%>"

Then in your html after your chart canvas put something like...

<div class="text-center verticaltext_content">Y Axis Label</div>

It is not the most elegant solution, but worked well when I had a few layers between the html and the chart code (using angular-chart and not wanting to change any source code).

Convert hex color value ( #ffffff ) to integer value

Try this, create drawable in your resource...

<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <solid android:color="@color/white"/>
    <size android:height="20dp"
        android:width="20dp"/>
</shape>

then use...

 Drawable mDrawable = getActivity().getResources().getDrawable(R.drawable.bg_rectangle_multicolor);
mDrawable.setColorFilter(Color.parseColor(color), PorterDuff.Mode.SRC_IN);
mView1.setBackground(mDrawable);

with color... "#FFFFFF"

if the color is transparent use... setAlpha

mView1.setAlpha(x); with x float 0-1 Ej (0.9f)

Good Luck

Java: Converting String to and from ByteBuffer and associated problems

Check out the CharsetEncoder and CharsetDecoder API descriptions - You should follow a specific sequence of method calls to avoid this problem. For example, for CharsetEncoder:

  1. Reset the encoder via the reset method, unless it has not been used before;
  2. Invoke the encode method zero or more times, as long as additional input may be available, passing false for the endOfInput argument and filling the input buffer and flushing the output buffer between invocations;
  3. Invoke the encode method one final time, passing true for the endOfInput argument; and then
  4. Invoke the flush method so that the encoder can flush any internal state to the output buffer.

By the way, this is the same approach I am using for NIO although some of my colleagues are converting each char directly to a byte in the knowledge they are only using ASCII, which I can imagine is probably faster.

Angular ng-class if else

You can use the ternary operator notation:

<div id="homePage" ng-class="page.isSelected(1)? 'center' : 'left'">

No connection could be made because the target machine actively refused it (PHP / WAMP)

All I have to do in order to get rid of that error was to restart my wamp server.

How to make a smaller RatingBar?

After a lot of research I found the best solution to reduce the size of custom rating bars is to get the size of progress drawable in certain sizes as mentioned below :

xxhdpi - 48*48 px

xhdpi - 36*36 px

hdpi - 24*24 px

And in style put the minheight and maxheight as 16 dp for all Resolution.

Let me know if this doesn't help you to get a best small size rating bars as these sizes I found very compatible and equivalent to ratingbar.small style attribute.

Why does DEBUG=False setting make my django Static Files Access fail?

If you are using the static serve view in development, you have to have DEBUG = True :

Warning

This will only work if DEBUG is True.

That's because this view is grossly inefficient and probably insecure. This is only intended for local development, and should never be used in production.

Docs: serving static files in developent

EDIT: You could add some urls just to test your 404 and 500 templates, just use the generic view direct_to_template in your urls.

from django.views.generic.simple import direct_to_template

urlpatterns = patterns('',
    ('^404testing/$', direct_to_template, {'template': '404.html'})
)

Adding a Method to an Existing Object Instance

Apart from what others said, I found that __repr__ and __str__ methods can't be monkeypatched on object level, because repr() and str() use class-methods, not locally-bounded object methods:

# Instance monkeypatch
[ins] In [55]: x.__str__ = show.__get__(x)                                                                 

[ins] In [56]: x                                                                                           
Out[56]: <__main__.X at 0x7fc207180c10>

[ins] In [57]: str(x)                                                                                      
Out[57]: '<__main__.X object at 0x7fc207180c10>'

[ins] In [58]: x.__str__()                                                                                 
Nice object!

# Class monkeypatch
[ins] In [62]: X.__str__ = lambda _: "From class"                                                          

[ins] In [63]: str(x)                                                                                      
Out[63]: 'From class'

How to get json key and value in javascript?

var data = {"name": "", "skills": "", "jobtitel": "Entwickler", "res_linkedin": "GwebSearch"}

var parsedData = JSON.parse(data);
alert(parsedData.name);
alert(parsedData.skills);
alert(parsedData.jobtitel);
alert(parsedData.res_linkedin);

Rest-assured. Is it possible to extract value from request json?

There are several ways. I personally use the following ones:

extracting single value:

String user_Id =
given().
when().
then().
extract().
        path("user_id");

work with the entire response when you need more than one:

Response response =
given().
when().
then().
extract().
        response();

String userId = response.path("user_id");

extract one using the JsonPath to get the right type:

long userId =
given().
when().
then().
extract().
        jsonPath().getLong("user_id");

Last one is really useful when you want to match against the value and the type i.e.

assertThat(
    when().
    then().
    extract().
            jsonPath().getLong("user_id"), equalTo(USER_ID)
);

The rest-assured documentation is quite descriptive and full. There are many ways to achieve what you are asking: https://github.com/jayway/rest-assured/wiki/Usage

How to send email to multiple recipients using python smtplib?

I use python 3.6 and the following code works for me

email_send = '[email protected],[email protected]'
server.sendmail(email_user,email_send.split(','),text)    

How can I get the username of the logged-in user in Django?

You can use the request object to find the logged in user

def my_view(request):
    username = None
    if request.user.is_authenticated():
        username = request.user.username

According to https://docs.djangoproject.com/en/2.0/releases/1.10/

In version Django 2.0 the syntax has changed to

request.user.is_authenticated

Getting list of files in documents folder

This code prints out all the directories and files in my documents directory:

Some modification of your function:

func listFilesFromDocumentsFolder() -> [String]
{
    let dirs = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.allDomainsMask, true)
    if dirs != [] {
        let dir = dirs[0]
        let fileList = try! FileManager.default.contentsOfDirectory(atPath: dir)
        return fileList
    }else{
        let fileList = [""]
        return fileList
    }
}

Which gets called by:

    let fileManager:FileManager = FileManager.default
    let fileList = listFilesFromDocumentsFolder()

    let count = fileList.count

    for i in 0..<count
    {
        if fileManager.fileExists(atPath: fileList[i]) != true
        {
            print("File is \(fileList[i])")
        }
    }

Use a JSON array with objects with javascript

This isn't a single JSON object. You have an array of JSON objects. You need to loop over array first and then access each object. Maybe the following kickoff example is helpful:

var arrayOfObjects = [{
  "id": 28,
  "Title": "Sweden"
}, {
  "id": 56,
  "Title": "USA"
}, {
  "id": 89,
  "Title": "England"
}];

for (var i = 0; i < arrayOfObjects.length; i++) {
  var object = arrayOfObjects[i];
  for (var property in object) {
    alert('item ' + i + ': ' + property + '=' + object[property]);
  }
  // If property names are known beforehand, you can also just do e.g.
  // alert(object.id + ',' + object.Title);
}

If the array of JSON objects is actually passed in as a plain vanilla string, then you would indeed need eval() here.

var string = '[{"id":28,"Title":"Sweden"}, {"id":56,"Title":"USA"}, {"id":89,"Title":"England"}]';
var arrayOfObjects = eval(string);
// ...

To learn more about JSON, check MDN web docs: Working with JSON .

Laravel - htmlspecialchars() expects parameter 1 to be string, object given

You could use serialize

<input type="hidden" name="quotation[]" value="{{serialize($quotation)}}">

But best way in this case use the json_encode method in your blade and json_decode in controller.

How to iterate through property names of Javascript object?

In JavaScript 1.8.5, Object.getOwnPropertyNames returns an array of all properties found directly upon a given object.

Object.getOwnPropertyNames ( obj )

and another method Object.keys, which returns an array containing the names of all of the given object's own enumerable properties.

Object.keys( obj )

I used forEach to list values and keys in obj, same as for (var key in obj) ..

Object.keys(obj).forEach(function (key) {
      console.log( key , obj[key] );
});

This all are new features in ECMAScript , the mothods getOwnPropertyNames, keys won't supports old browser's.

How to paste text to end of every line? Sublime 2

Use column selection. Column selection is one of the unique features of Sublime2; it is used to give you multiple matched cursors (tutorial here). To get multiple cursors, do one of the following:

Mouse:

  • Hold down the shift (Windows/Linux) or option key (Mac) while selecting a region with the mouse.

  • Clicking middle mouse button (or scroll) will select as a column also.

Keyboard:

  • Select the desired region.
  • Type control+shift+L (Windows/Linux) or command+shift+L (Mac)

You now have multiple lines selected, so you could type a quotation mark at the beginning and end of each line. It would be better to take advantage of Sublime's capabilities, and just type ". When you do this, Sublime automatically quotes the selected text.

Type esc to exit multiple cursor mode.

DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled

Try setting the definer for the function!

So instead of

CREATE FUNCTION get_pet_owner

you will write something akin to

CREATE DEFINER=procadmin@% FUNCTION get_pet_owner

which ought to work if the user prodacmin has rights to create functions/procedures.

In my case the function worked when generated through MySQL Workbench but did not work when run directly as an SQL script. Making the changes above fixed the problem.

Copy folder structure (without files) from one location to another

Substitute target_dir and source_dir with the appropriate values:

cd target_dir && (cd source_dir; find . -type d ! -name .) | xargs -i mkdir -p "{}"

Tested on OSX+Ubuntu.

Postgres: How to convert a json string to text?

There is no way in PostgreSQL to deconstruct a scalar JSON object. Thus, as you point out,

select  length(to_json('Some "text"'::TEXT) ::TEXT);

is 15,

The trick is to convert the JSON into an array of one JSON element, then extract that element using ->>.

select length( array_to_json(array[to_json('Some "text"'::TEXT)])->>0 );

will return 11.

Increment variable value by 1 ( shell programming)

These are the methods I know:

ichramm@NOTPARALLEL ~$ i=10; echo $i;
10
ichramm@NOTPARALLEL ~$ ((i+=1)); echo $i;
11
ichramm@NOTPARALLEL ~$ ((i=i+1)); echo $i;
12
ichramm@NOTPARALLEL ~$ i=`expr $i + 1`; echo $i;
13

Note the spaces in the last example, also note that's the only one that uses $i.

TypeError: 'function' object is not subscriptable - Python

You can use this:

bankHoliday= [1, 0, 1, 1, 2, 0, 0, 1, 0, 0, 0, 2] #gives the list of bank holidays in each month

def bank_holiday(month):
   month -= 1#Takes away the numbers from the months, as months start at 1 (January) not at 0. There is no 0 month.
   print(bankHoliday[month])

bank_holiday(int(input("Which month would you like to check out: ")))

What causes imported Maven project in Eclipse to use Java 1.5 instead of Java 1.6 by default and how can I ensure it doesn't?

I found that my issue was someone committed the file .project and .classpath that had references to Java1.5 as the default JRE.

<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/J2SE-1.5">
    <attributes>
        <attribute name="owner.project.facets" value="java"/>
    </attributes>
</classpathentry>

By closing the project, removing the files, and then re-importing as a Maven project, I was able to properly set the project to use workspace JRE or the relevant jdk without it reverting back to 1.5 . Thus, avoid checking into your SVN the .project and .classpath files

Hope this helps others.

How can I escape double quotes in XML attributes values?

A double quote character (") can be escaped as &quot;, but here's the rest of the story...

Double quote character must be escaped in this context:

  • In XML attributes delimited by double quotes:

    <EscapeNeeded name="Pete &quot;Maverick&quot; Mitchell"/>
    

Double quote character need not be escaped in most contexts:

  • In XML textual content:

    <NoEscapeNeeded>He said, "Don't quote me."</NoEscapeNeeded>
    
  • In XML attributes delimited by single quotes ('):

    <NoEscapeNeeded name='Pete "Maverick" Mitchell'/>
    

    Similarly, (') require no escaping if (") are used for the attribute value delimiters:

    <NoEscapeNeeded name="Pete 'Maverick' Mitchell"/>
    

See also

Pandas dataframe get first row of each group

If you only need the first row from each group we can do with drop_duplicates, Notice the function default method keep='first'.

df.drop_duplicates('id')
Out[1027]: 
    id   value
0    1   first
3    2   first
5    3   first
9    4  second
11   5   first
12   6   first
15   7  fourth

Fastest way to check if a string is JSON in PHP?

This is what I recommend

if (!in_array(substr($string, 0, 1), ['{', '[']) || !in_array(substr($string, -1), ['}', ']'])) {
  return false;
} else {
  json_decode($string);
  return (json_last_error() === JSON_ERROR_NONE);
}

Can I read the hash portion of the URL on my server-side application (PHP, Ruby, Python, etc.)?

The answer is no.

The main purpose of the hash is to scroll to a certain part of the page where you have defined a bookmark. e.g. Scroll to this Part when page loads.

The browse will scroll such that this line is the first visible content in the page, depending on how much content follows below the line.

Yes javascript can acces it, and then a simple ajax call will do the magic

Creating a Plot Window of a Particular Size

Use dev.new(). (See this related question.)

plot(1:10)
dev.new(width=5, height=4)
plot(1:20)

To be more specific which units are used:

dev.new(width=5, height=4, unit="in")
plot(1:20)
dev.new(width = 550, height = 330, unit = "px")
plot(1:15)

edit additional argument for Rstudio (May 2020), (thanks user Soren Havelund Welling)

For Rstudio, add dev.new(width=5,height=4,noRStudioGD = TRUE)

'App not Installed' Error on Android

If you tried all the answers above and none of them worked, you might want to try this:

If your build variant is 'debug', then you should add this under buildTypes in the app build gradle for the app to install on your device:

debug {
    minifyEnabled false
}

if-else statement inside jsx: ReactJS

You can't provide if-else condition in the return block, make use of ternary block, also this.state will be an object, you shouldn't be comparing it with a value, see which state value you want to check, also return returns only one element, make sure to wrap them in a View

render() {
    return (
      <View style={styles.container}>
      {this.state.page === 'news'? <Text>data</Text>: null}
      </View>

     )
}

Extract MSI from EXE

Starting with parameter:

setup.exe /A

asks for saving included files (including MSI).

This may depend on the software which created the setup.exe.

Call a PHP function after onClick HTML event

You don't need javascript for doing so. Just delete the onClick and write the php Admin.php file like this:

<!-- HTML STARTS-->
<?php
//If all the required fields are filled
if (!empty($GET_['fullname'])&&!empty($GET_['email'])&&!empty($GET_['name']))
{
function addNewContact()
    {
    $new = '{';
    $new .= '"fullname":"' . $_GET['fullname'] . '",';
    $new .= '"email":"' . $_GET['email'] . '",';
    $new .= '"phone":"' . $_GET['phone'] . '",';
    $new .= '}';
    return $new;
    }

function saveContact()
    {
    $datafile = fopen ("data/data.json", "a+");
    if(!$datafile){
        echo "<script>alert('Data not existed!')</script>";
        } 
    else{
        $contact_list = $contact_list . addNewContact();
        file_put_contents("data/data.json", $contact_list);
        }
    fclose($datafile);
    }

// Call the function saveContact()
saveContact();
echo "Thank you for joining us";
}
else //If the form is not submited or not all the required fields are filled

{ ?>

<form>
    <fieldset>
        <legend>Add New Contact</legend>
        <input type="text" name="fullname" placeholder="First name and last name" required /> <br />
        <input type="email" name="email" placeholder="[email protected]" required /> <br />
        <input type="text" name="phone" placeholder="Personal phone number: mobile, home phone etc." required /> <br />
        <input type="submit" name="submit" class="button" value="Add Contact"/>
        <input type="button" name="cancel" class="button" value="Reset" />
    </fieldset>
</form>
<?php }
?>
<!-- HTML ENDS -->

Thought I don't like the PHP bit. Do you REALLY want to create a file for contacts? It'd be MUCH better to use a mysql database. Also, adding some breaks to that file would be nice too...

Other thought, IE doesn't support placeholder.

SQLException: No suitable Driver Found for jdbc:oracle:thin:@//localhost:1521/orcl

i have changed my old path: jdbc:odbc:thin:@localhost:1521:orcl

to new : jdbc:oracle:thin:@//localhost:1521/orcl

and it worked for me.....hurrah!! image

Laravel blank white screen

Facing the blank screen in Laravel 5.8. Every thing seems fine with both storage and bootstrap folder given 777 rights. On

php artisan cache:clear

It shows the problem it was the White spaces in App Name of .env file

Bootstrap how to get text to vertical align in a div container

h2.text-left{
  position:relative;
  top:50%;
  transform: translateY(-50%);
  -webkit-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
}

Explanation:

The top:50% style essentially pushes the header element down 50% from the top of the parent element. The translateY stylings also act in a similar manner by moving then element down 50% from the top.

Please note that this works well for headers with 1 (maybe 2) lines of text as this simply moves the top of the header element down 50% and then the rest of the content fills in below that, which means that with multiple lines of text it would appear to be slightly below vertically aligned.

A possible fix for multiple lines would be to use a percentage slightly less than 50%.

How to read response headers in angularjs?

Updated based on Muhammad's answer...

$http.get('/someUrl').
  success(function(data, status, headers, config) {
    // this callback will be called asynchronously
    // when the response is available
    console.log(headers()['Content-Range']);
  })
  .error(function(data, status, headers, config) {
    // called asynchronously if an error occurs
    // or server returns response with an error status.
  });

git discard all changes and pull from upstream

git reset <hash>  # you need to know the last good hash, so you can remove all your local commits

git fetch upstream
git checkout master
git merge upstream/master
git push origin master -f

voila, now your fork is back to same as upstream.

Error in contrasts when defining a linear model in R

If the error happens to be because your data has NAs, then you need to set the glm() function options of how you would like to treat the NA cases. More information on this is found in a relevant post here: https://stats.stackexchange.com/questions/46692/how-the-na-values-are-treated-in-glm-in-r

Is it possible to use vh minus pixels in a CSS calc()?

It does work indeed. Issue was with my less compiler. It was compiled in to:

.container {
  min-height: calc(-51vh);
}

Fixed with the following code in less file:

.container {
  min-height: calc(~"100vh - 150px");
}

Thanks to this link: Less Aggressive Compilation with CSS3 calc

Sort a two dimensional array based on one column

  1. install java8 jdk+jre

  2. use lamda expression to sort 2D array.

code:

import java.util.Arrays;
import java.util.Comparator;

class SortString {

    public static void main(final String[] args) {
        final String[][] data = new String[][] {
                new String[] { "2009.07.25 20:24", "Message A" },
                new String[] { "2009.07.25 20:17", "Message G" },
                new String[] { "2009.07.25 20:25", "Message B" },
                new String[] { "2009.07.25 20:30", "Message D" },
                new String[] { "2009.07.25 20:01", "Message F" },
                new String[] { "2009.07.25 21:08", "Message E" },
                new String[] { "2009.07.25 19:54", "Message R" } 
        };
        // this is applicable only in java 8 version.
        Arrays.sort(data, (String[] s1, String[] s2) -> s1[0].compareTo(s2[0]));

        // we can also use Comparator.comparing and point to Comparable value we want to use        
        // Arrays.sort(data, Comparator.comparing(row->row[0]));

        for (final String[] s : data) {
            System.out.println(s[0] + " " + s[1]);
        }
    }
}

output

2009.07.25 19:54 Message R
2009.07.25 20:01 Message F
2009.07.25 20:17 Message G
2009.07.25 20:24 Message A
2009.07.25 20:25 Message B
2009.07.25 20:30 Message D
2009.07.25 21:08 Message E

Why is my JQuery selector returning a n.fn.init[0], and what is it?

Another approach(Inside of $function to asure that the each is executed on document ready):

var ids = [1,2];
$(function(){
  $('.checkbox-wrapper>input[type="checkbox"]').each(function(i,item){
    if(ids.indexOf($(item).data('id')) > -1){
       $(item).prop("checked", "checked");
    }
  });
});

Working fiddle: https://jsfiddle.net/robertrozas/w5uda72v/

What is the n.fn.init[0], and why it is returned? Why are my two seemingly identical JQuery functions returning different things?

Answer: It seems that your elements are not in the DOM yet, when you are trying to find them. As @Rory McCrossan pointed out, the length:0 means that it doesn't find any element based on your search criteria.

About n.fn.init[0], lets look at the core of the Jquery Library:

var jQuery = function( selector, context ) {
   return new jQuery.fn.init( selector, context );
};

Looks familiar, right?, now in a minified version of jquery, this should looks like:

var n = function( selector, context ) {
   return new n.fn.init( selector, context );
};

So when you use a selector you are creating an instance of the jquery function; when found an element based on the selector criteria it returns the matched elements; when the criteria does not match anything it returns the prototype object of the function.

Select n random rows from SQL Server table

Selecting Rows Randomly from a Large Table on MSDN has a simple, well-articulated solution that addresses the large-scale performance concerns.

  SELECT * FROM Table1
  WHERE (ABS(CAST(
  (BINARY_CHECKSUM(*) *
  RAND()) as int)) % 100) < 10

[ :Unexpected operator in shell programming

There is no mistake in your bash script. But you are executing it with sh which has a less extensive syntax ;)

So, run bash ./choose.sh instead :)

Deep copy in ES6 using the spread syntax

function deepclone(obj) {
    let newObj = {};

    if (typeof obj === 'object') {
        for (let key in obj) {
            let property = obj[key],
                type = typeof property;
            switch (type) {
                case 'object':
                    if( Object.prototype.toString.call( property ) === '[object Array]' ) {
                        newObj[key] = [];
                        for (let item of property) {
                            newObj[key].push(this.deepclone(item))
                        }
                    } else {
                        newObj[key] = deepclone(property);
                    }
                    break;
                default:
                    newObj[key] = property;
                    break;

            }
        }
        return newObj
    } else {
        return obj;
    }
}

console.log(result) returns [object Object]. How do I get result.name?

Try adding JSON.stringify(result) to convert the JS Object into a JSON string.

From your code I can see you are logging the result in error which is called if the AJAX request fails, so I'm not sure how you'd go about accessing the id/name/etc. then (you are checking for success inside the error condition!).

Note that if you use Chrome's console you should be able to browse through the object without having to stringify the JSON, which makes it easier to debug.

Split string into tokens and save them in an array

Why strtok() is a bad idea

Do not use strtok() in normal code, strtok() uses static variables which have some problems. There are some use cases on embedded microcontrollers where static variables make sense but avoid them in most other cases. strtok() behaves unexpected when more than 1 thread uses it, when it is used in a interrupt or when there are some other circumstances where more than one input is processed between successive calls to strtok(). Consider this example:

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

//Splits the input by the / character and prints the content in between
//the / character. The input string will be changed
void printContent(char *input)
{
    char *p = strtok(input, "/");
    while(p)
    {
        printf("%s, ",p);
        p = strtok(NULL, "/");
    }
}

int main(void)
{
    char buffer[] = "abc/def/ghi:ABC/DEF/GHI";
    char *p = strtok(buffer, ":");
    while(p)
    {
        printContent(p);
        puts(""); //print newline
        p = strtok(NULL, ":");
    }
    return 0;
}

You may expect the output:

abc, def, ghi,
ABC, DEF, GHI,

But you will get

abc, def, ghi,

This is because you call strtok() in printContent() resting the internal state of strtok() generated in main(). After returning, the content of strtok() is empty and the next call to strtok() returns NULL.

What you should do instead

You could use strtok_r() when you use a POSIX system, this versions does not need static variables. If your library does not provide strtok_r() you can write your own version of it. This should not be hard and Stackoverflow is not a coding service, you can write it on your own.

Checking if a website is up via Python

The HTTPConnection object from the httplib module in the standard library will probably do the trick for you. BTW, if you start doing anything advanced with HTTP in Python, be sure to check out httplib2; it's a great library.

How to strip comma in Python string

This will strip all commas from the text and left justify it.

for row in inputfile:
    place = row['your_row_number_here'].strip(', ')

? ????? ??????

Reducing MongoDB database file size

I had the same problem, and solved by simply doing this at the command line:

mongodump -d databasename
echo 'db.dropDatabase()' | mongo databasename
mongorestore dump/databasename

Firebase: how to generate a unique numeric ID for key?

I'd suggest reading through the Firebase documentation. Specifically, see the Saving Data portion of the Firebase JavaScript Web Guide.

From the guide:

Getting the Unique ID Generated by push()

Calling push() will return a reference to the new data path, which you can use to get the value of its ID or set data to it. The following code will result in the same data as the above example, but now we'll have access to the unique push ID that was generated

// Generate a reference to a new location and add some data using push()
var newPostRef = postsRef.push({
 author: "gracehop",
 title: "Announcing COBOL, a New Programming Language"
});

// Get the unique ID generated by push() by accessing its key
var postID = newPostRef.key;

Source: https://firebase.google.com/docs/database/admin/save-data#section-ways-to-save

  • A push generates a new data path, with a server timestamp as its key. These keys look like -JiGh_31GA20JabpZBfa, so not numeric.
  • If you wanted to make a numeric only ID, you would make that a parameter of the object to avoid overwriting the generated key.
    • The keys (the paths of the new data) are guaranteed to be unique, so there's no point in overwriting them with a numeric key.
    • You can instead set the numeric ID as a child of the object.
    • You can then query objects by that ID child using Firebase Queries.

From the guide:

In JavaScript, the pattern of calling push() and then immediately calling set() is so common that we let you combine them by just passing the data to be set directly to push() as follows. Both of the following write operations will result in the same data being saved to Firebase:

// These two methods are equivalent:
postsRef.push().set({
  author: "gracehop",
  title: "Announcing COBOL, a New Programming Language"
});
postsRef.push({
  author: "gracehop",
  title: "Announcing COBOL, a New Programming Language"
});

Source: https://firebase.google.com/docs/database/admin/save-data#getting-the-unique-key-generated-by-push

MySQL Workbench - Connect to a Localhost

You need to install mysql server for your machine first. Once done, you will be able to add local db details to it.

For e.g. IP: 127.0.0.1
port: 3306
user: root
pass: pass of root which you have set

Here is the link on step by step guide for linux.

https://support.rackspace.com/how-to/install-mysql-server-on-the-ubuntu-operating-system/

an attempt was made to access a socket in a way forbbiden by its access permissions. why?

This is the error that is returned when the Windows Firewall blocks the port (out-going). We have a strict web server so the outgoing ports are blocked by default. All I had to do was to create a rule to allow the TCP port number in wf.msc.

Angular.js programmatically setting a form field to dirty

Angular 2

For anyone looking to do the same in Angular 2 it is very similar apart from getting a hold of the form

<form role="form" [ngFormModel]="myFormModel" (ngSubmit)="onSubmit()" #myForm="ngForm">
<div class="form-group">
    <label for="name">Name</label>
    <input autofocus type="text" ngControl="usename" #name="ngForm" class="form-control" id="name" placeholder="Name">
    <div [hidden]="name.valid || name.pristine" class="alert alert-danger">
        Name is required
    </div>
</div>
</form>
<button type="submit" class="btn btn-primary" (click)="myForm.ngSubmit.emit()">Add</button>

import { Component, } from '@angular/core';
import { FormBuilder, Validators } from '@angular/common';

@Component({
    selector: 'my-example-form',
    templateUrl: 'app/my-example-form.component.html',
    directives: []
})
export class MyFormComponent {
    myFormModel: any;

    constructor(private _formBuilder: FormBuilder) {
        this.myFormModel = this._formBuilder.group({
            'username': ['', Validators.required],
            'password': ['', Validators.required]
        });
    }

    onSubmit() {
        this.myFormModel.markAsDirty();
        for (let control in this.myFormModel.controls) {
            this.myFormModel.controls[control].markAsDirty();
        };

        if (this.myFormModel.dirty && this.myFormModel.valid) {
            // My submit logic
        }
    }
}

NSCameraUsageDescription in iOS 10.0 runtime crash?

I had the same problem and could not find a solution. Mark90 is right there are a lot info.plist files and you should edit the correct. Go to Project, under TARGETS select the project (not the tests), in the tab bar select Info and add the permission under "Custom iOS Target Properties".

..The underlying connection was closed: An unexpected error occurred on a receive

  • .NET 4.6 and above. You don’t need to do any additional work to support TLS 1.2, it’s supported by default.
  • .NET 4.5. TLS 1.2 is supported, but it’s not a default protocol. You need to opt-in to use it. The following code will make TLS 1.2 default, make sure to execute it before making a connection to secured resource:
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

  • .NET 4.0. TLS 1.2 is not supported, but if you have .NET 4.5 (or above) installed on the system then you still can opt in for TLS 1.2 even if your application framework doesn’t support it. The only problem is that SecurityProtocolType in .NET 4.0 doesn’t have an entry for TLS1.2, so we’d have to use a numerical representation of this enum value:
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

  • .NET 3.5 or below. TLS 1.2 is not supported. Upgrade your application to more recent version of the framework.

How can I confirm a database is Oracle & what version it is using SQL?

There are different ways to check Oracle Database Version. Easiest way is to run the below SQL query to check Oracle Version.

SQL> SELECT * FROM PRODUCT_COMPONENT_VERSION;
SQL> SELECT * FROM v$version;

Download a working local copy of a webpage

wget is capable of doing what you are asking. Just try the following:

wget -p -k http://www.example.com/

The -p will get you all the required elements to view the site correctly (css, images, etc). The -k will change all links (to include those for CSS & images) to allow you to view the page offline as it appeared online.

From the Wget docs:

‘-k’
‘--convert-links’
After the download is complete, convert the links in the document to make them
suitable for local viewing. This affects not only the visible hyperlinks, but
any part of the document that links to external content, such as embedded images,
links to style sheets, hyperlinks to non-html content, etc.

Each link will be changed in one of the two ways:

    The links to files that have been downloaded by Wget will be changed to refer
    to the file they point to as a relative link.

    Example: if the downloaded file /foo/doc.html links to /bar/img.gif, also
    downloaded, then the link in doc.html will be modified to point to
    ‘../bar/img.gif’. This kind of transformation works reliably for arbitrary
    combinations of directories.

    The links to files that have not been downloaded by Wget will be changed to
    include host name and absolute path of the location they point to.

    Example: if the downloaded file /foo/doc.html links to /bar/img.gif (or to
    ../bar/img.gif), then the link in doc.html will be modified to point to
    http://hostname/bar/img.gif. 

Because of this, local browsing works reliably: if a linked file was downloaded,
the link will refer to its local name; if it was not downloaded, the link will
refer to its full Internet address rather than presenting a broken link. The fact
that the former links are converted to relative links ensures that you can move
the downloaded hierarchy to another directory.

Note that only at the end of the download can Wget know which links have been
downloaded. Because of that, the work done by ‘-k’ will be performed at the end
of all the downloads. 

Apache Proxy: No protocol handler was valid

To clarify for future reference, a2enmod, as is suggested in several answers above, is for Debian/Ubuntu. Red Hat does not use this to enable Apache modules - instead it uses LoadModule statements in httpd.conf.

More here: https://serverfault.com/questions/56394/how-do-i-enable-apache-modules-from-the-command-line-in-redhat

The resolution/correct answer is in the comments on the OP:

I think you need mod_ssl and SSLProxyEngine with ProxyPass – Deadooshka May 29 '14 at 11:35

@Deadooshka Yes, this is working. If you post this as an answer, I can accept it – das_j May 29 '14 at 12:04

SQL - Create view from multiple tables

This works too and you dont have to use join or anything:

DROP VIEW IF EXISTS yourview;

CREATE VIEW yourview AS
    SELECT table1.column1, 
    table2.column2
FROM 
table1, table2 
WHERE table1.column1 = table2.column1;

What do Clustered and Non clustered index actually mean?

Let me offer a textbook definition on "clustering index", which is taken from 15.6.1 from Database Systems: The Complete Book:

We may also speak of clustering indexes, which are indexes on an attribute or attributes such that all of tuples with a fixed value for the search key of this index appear on roughly as few blocks as can hold them.

To understand the definition, let's take a look at Example 15.10 provided by the textbook:

A relation R(a,b) that is sorted on attribute a and stored in that order, packed into blocks, is surely clusterd. An index on a is a clustering index, since for a given a-value a1, all the tuples with that value for a are consecutive. They thus appear packed into blocks, execept possibly for the first and last blocks that contain a-value a1, as suggested in Fig.15.14. However, an index on b is unlikely to be clustering, since the tuples with a fixed b-value will be spread all over the file unless the values of a and b are very closely correlated.

Fig 15.14

Note that the definition does not enforce the data blocks have to be contiguous on the disk; it only says tuples with the search key are packed into as few data blocks as possible.

A related concept is clustered relation. A relation is "clustered" if its tuples are packed into roughly as few blocks as can possibly hold those tuples. In other words, from a disk block perspective, if it contains tuples from different relations, then those relations cannot be clustered (i.e., there is a more packed way to store such relation by swapping the tuples of that relation from other disk blocks with the tuples the doesn't belong to the relation in the current disk block). Clearly, R(a,b) in example above is clustered.

To connect two concepts together, a clustered relation can have a clustering index and nonclustering index. However, for non-clustered relation, clustering index is not possible unless the index is built on top of the primary key of the relation.

"Cluster" as a word is spammed across all abstraction levels of database storage side (three levels of abstraction: tuples, blocks, file). A concept called "clustered file", which describes whether a file (an abstraction for a group of blocks (one or more disk blocks)) contains tuples from one relation or different relations. It doesn't relate to the clustering index concept as it is on file level.

However, some teaching material likes to define clustering index based on the clustered file definition. Those two types of definitions are the same on clustered relation level, no matter whether they define clustered relation in terms of data disk block or file. From the link in this paragraph,

An index on attribute(s) A on a file is a clustering index when: All tuples with attribute value A = a are stored sequentially (= consecutively) in the data file

Storing tuples consecutively is the same as saying "tuples are packed into roughly as few blocks as can possibly hold those tuples" (with minor difference on one talking about file, the other talking about disk). It's because storing tuple consecutively is the way to achieve "packed into roughly as few blocks as can possibly hold those tuples".

Cannot open Windows.h in Microsoft Visual Studio

The right combination of Windows SDK Version and Platform Toolset needs to be selected Depends of course what toolset you have currently installed

SDK Version and Platform Toolset

Subtracting 1 day from a timestamp date

Use the INTERVAL type to it. E.g:

--yesterday
SELECT NOW() - INTERVAL '1 DAY';

--Unrelated to the question, but PostgreSQL also supports some shortcuts:
SELECT 'yesterday'::TIMESTAMP, 'tomorrow'::TIMESTAMP, 'allballs'::TIME;

Then you can do the following on your query:

SELECT 
    org_id,
    count(accounts) AS COUNT,
    ((date_at) - INTERVAL '1 DAY') AS dateat
FROM 
    sourcetable
WHERE 
    date_at <= now() - INTERVAL '130 DAYS'
GROUP BY 
    org_id,
    dateat;


TIPS

Tip 1

You can append multiple operands. E.g.: how to get last day of current month?

SELECT date_trunc('MONTH', CURRENT_DATE) + INTERVAL '1 MONTH - 1 DAY';

Tip 2

You can also create an interval using make_interval function, useful when you need to create it at runtime (not using literals):

SELECT make_interval(days => 10 + 2);
SELECT make_interval(days => 1, hours => 2);
SELECT make_interval(0, 1, 0, 5, 0, 0, 0.0);


More info:

Date/Time Functions and Operators

datatype-datetime (Especial values).

What linux shell command returns a part of a string?

expr(1) has a substr subcommand:

expr substr <string> <start-index> <length>

This may be useful if you don't have bash (perhaps embedded Linux) and you don't want the extra "echo" process you need to use cut(1).

Preventing scroll bars from being hidden for MacOS trackpad users in WebKit/Blink

Here is a shorter bit of code that reenables scroll bars across your entire website. I'm not sure if it's much different than the current most popular answer but here it is:

::-webkit-scrollbar {
    -webkit-appearance: none;
    width: 7px;
}
::-webkit-scrollbar-thumb {
    border-radius: 4px;
    background-color: rgba(0,0,0,.5);
    box-shadow: 0 0 1px rgba(255,255,255,.5);
}

Found at this link: http://simurai.com/blog/2011/07/26/webkit-scrollbar

Java: Difference between the setPreferredSize() and setSize() methods in components

IIRC ...

setSize sets the size of the component.

setPreferredSize sets the preferred size. The Layoutmanager will try to arrange that much space for your component.

It depends on whether you're using a layout manager or not ...

How to list all properties of a PowerShell object

The most succinct way to do this is:

Get-WmiObject -Class win32_computersystem -Property *

Putting HTML inside Html.ActionLink(), plus No Link Text?

Please try below Code that may help you.

 @Html.ActionLink(" SignIn", "Login", "Account", routeValues: null, htmlAttributes: new {  id = "loginLink" ,**@class="glyphicon glyphicon-log-in"** }) 

Moving Average Pandas

To get the moving average in pandas we can use cum_sum and then divide by count.

Here is the working example:

import pandas as pd
import numpy as np

df = pd.DataFrame({'id': range(5),
                   'value': range(100,600,100)})

# some other similar statistics
df['cum_sum'] = df['value'].cumsum()
df['count'] = range(1,len(df['value'])+1)
df['mov_avg'] = df['cum_sum'] / df['count']

# other statistics
df['rolling_mean2'] = df['value'].rolling(window=2).mean()

print(df)

output

   id  value  cum_sum  count  mov_avg     rolling_mean2
0   0    100      100      1    100.0           NaN
1   1    200      300      2    150.0           150.0
2   2    300      600      3    200.0           250.0
3   3    400     1000      4    250.0           350.0
4   4    500     1500      5    300.0           450.0

How to get list of all installed packages along with version in composer?

The behaviour of this command as been modified so you don't have to pass the -i option:

[10:19:05] coil@coil:~/workspace/api$ composer show -i
You are using the deprecated option "installed". 
Only installed packages are shown by default now. 
The --all option can be used to show all packages.

For vs. while in C programming?

One common misunderstanding withwhile/for loops I've seen is that their efficiency differs. While loops and for loops are equally efficient. I remember my computer teacher from highschool told me that for loops are more efficient for iteration when you have to increment a number. That is not the case.

For loops are simply syntactically sugared while loops, and make iteration code faster to write.

When the compiler takes your code and compiles it, it is translating it into a form that is easier for the computer to understand and execute on a lower level (assembly). During this translation, the subtle differences between the while and for syntaxes are lost, and they become exactly the same.

The role of #ifdef and #ifndef

Text inside an ifdef/endif or ifndef/endif pair will be left in or removed by the pre-processor depending on the condition. ifdef means "if the following is defined" while ifndef means "if the following is not defined".

So:

#define one 0
#ifdef one
    printf("one is defined ");
#endif
#ifndef one
    printf("one is not defined ");
#endif

is equivalent to:

printf("one is defined ");

since one is defined so the ifdef is true and the ifndef is false. It doesn't matter what it's defined as. A similar (better in my opinion) piece of code to that would be:

#define one 0
#ifdef one
    printf("one is defined ");
#else
    printf("one is not defined ");
#endif

since that specifies the intent more clearly in this particular situation.

In your particular case, the text after the ifdef is not removed since one is defined. The text after the ifndef is removed for the same reason. There will need to be two closing endif lines at some point and the first will cause lines to start being included again, as follows:

     #define one 0
+--- #ifdef one
|    printf("one is defined ");     // Everything in here is included.
| +- #ifndef one
| |  printf("one is not defined "); // Everything in here is excluded.
| |  :
| +- #endif
|    :                              // Everything in here is included again.
+--- #endif

Cannot find mysql.sock

Unfortunately none of the above have worked in my case. But finally I found solutions.

To find where is mysql.sock file, simply open xampp manager, select MySQL and click on Configure on the right. On the config panel click Open Conf File, and simply search for mysql.sock by pressing the CMD+F shortcut.

In my case, the owner of the mysql.sock was changed, and I had to change it back to root admin with: chmod root:admin mysql.sock

After that the database had been accessed.

How to parse XML in Bash?

This works if you are wanting XML attributes:

$ cat alfa.xml
<video server="asdf.com" stream="H264_400.mp4" cdn="limelight"/>

$ sed 's.[^ ]*..;s./>..' alfa.xml > alfa.sh

$ . ./alfa.sh

$ echo "$stream"
H264_400.mp4

Why do you use typedef when declaring an enum in C++?

In some C codestyle guide the typedef version is said to be preferred for "clarity" and "simplicity". I disagree, because the typedef obfuscates the real nature of the declared object. In fact, I don't use typedefs because when declaring a C variable I want to be clear about what the object actually is. This choice helps myself to remember faster what an old piece of code actually does, and will help others when maintaining the code in the future.

Using await outside of an async function

Top level await is not supported. There are a few discussions by the standards committee on why this is, such as this Github issue.

There's also a thinkpiece on Github about why top level await is a bad idea. Specifically he suggests that if you have code like this:

// data.js
const data = await fetch( '/data.json' );
export default data;

Now any file that imports data.js won't execute until the fetch completes, so all of your module loading is now blocked. This makes it very difficult to reason about app module order, since we're used to top level Javascript executing synchronously and predictably. If this were allowed, knowing when a function gets defined becomes tricky.

My perspective is that it's bad practice for your module to have side effects simply by loading it. That means any consumer of your module will get side effects simply by requiring your module. This badly limits where your module can be used. A top level await probably means you're reading from some API or calling to some service at load time. Instead you should just export async functions that consumers can use at their own pace.

What is a void pointer in C++?

A void* pointer is used when you want to indicate a pointer to a hunk of memory without specifying the type. C's malloc returns such a pointer, expecting you to cast it to a particular type immediately. It really isn't useful until you cast it to another pointer type. You're expected to know which type to cast it to, the compiler has no reflection capability to know what the underlying type should be.

Python function pointer

funcdict = {
  'mypackage.mymodule.myfunction': mypackage.mymodule.myfunction,
    ....
}

funcdict[myvar](parameter1, parameter2)

Finding current executable's path without /proc/self/exe

Depending on the version of QNX Neutrino, there are different ways to find the full path and name of the executable file that was used to start the running process. I denote the process identifier as <PID>. Try the following:

  1. If the file /proc/self/exefile exists, then its contents are the requested information.
  2. If the file /proc/<PID>/exefile exists, then its contents are the requested information.
  3. If the file /proc/self/as exists, then:
    1. open() the file.
    2. Allocate a buffer of, at least, sizeof(procfs_debuginfo) + _POSIX_PATH_MAX.
    3. Give that buffer as input to devctl(fd, DCMD_PROC_MAPDEBUG_BASE,....
    4. Cast the buffer to a procfs_debuginfo*.
    5. The requested information is at the path field of the procfs_debuginfo structure. Warning: For some reason, sometimes, QNX omits the first slash / of the file path. Prepend that / when needed.
    6. Clean up (close the file, free the buffer, etc.).
  4. Try the procedure in 3. with the file /proc/<PID>/as.
  5. Try dladdr(dlsym(RTLD_DEFAULT, "main"), &dlinfo) where dlinfo is a Dl_info structure whose dli_fname might contain the requested information.

I hope this helps.

OpenCV NoneType object has no attribute shape

Hope this helps anyone facing same issue

To know exactly where has occurred, since the running program doesn't mention it as a error with line number

'NoneType' object has no attribute 'shape'

Make sure to add assert after loading the image/frame

For image

image = cv2.imread('myimage.png')
assert not isinstance(image,type(None)), 'image not found'

For video

cap = cv2.VideoCapture(0)

    while(cap.isOpened()):

        # Capture frame-by-frame
        ret, frame = cap.read()
        if ret:
            assert not isinstance(frame,type(None)), 'frame not found'

Helped me solve a similar issue, in a long script

Div show/hide media query

It sounds like you may be wanting to access the viewport of the device. You can do this by inserting this meta tag in your header.

<meta name="viewport" content="width=device-width, initial-scale=1.0">

http://www.w3schools.com/css/css_rwd_viewport.asp

Find and replace string values in list

In case you're wondering about the performance of the different approaches, here are some timings:

In [1]: words = [str(i) for i in range(10000)]

In [2]: %timeit replaced = [w.replace('1', '<1>') for w in words]
100 loops, best of 3: 2.98 ms per loop

In [3]: %timeit replaced = map(lambda x: str.replace(x, '1', '<1>'), words)
100 loops, best of 3: 5.09 ms per loop

In [4]: %timeit replaced = map(lambda x: x.replace('1', '<1>'), words)
100 loops, best of 3: 4.39 ms per loop

In [5]: import re

In [6]: r = re.compile('1')

In [7]: %timeit replaced = [r.sub('<1>', w) for w in words]
100 loops, best of 3: 6.15 ms per loop

as you can see for such simple patterns the accepted list comprehension is the fastest, but look at the following:

In [8]: %timeit replaced = [w.replace('1', '<1>').replace('324', '<324>').replace('567', '<567>') for w in words]
100 loops, best of 3: 8.25 ms per loop

In [9]: r = re.compile('(1|324|567)')

In [10]: %timeit replaced = [r.sub('<\1>', w) for w in words]
100 loops, best of 3: 7.87 ms per loop

This shows that for more complicated substitutions a pre-compiled reg-exp (as in 9-10) can be (much) faster. It really depends on your problem and the shortest part of the reg-exp.

How to use a class object in C++ as a function parameter

class is a keyword that is used only* to introduce class definitions. When you declare new class instances either as local objects or as function parameters you use only the name of the class (which must be in scope) and not the keyword class itself.

e.g.

class ANewType
{
    // ... details
};

This defines a new type called ANewType which is a class type.

You can then use this in function declarations:

void function(ANewType object);

You can then pass objects of type ANewType into the function. The object will be copied into the function parameter so, much like basic types, any attempt to modify the parameter will modify only the parameter in the function and won't affect the object that was originally passed in.

If you want to modify the object outside the function as indicated by the comments in your function body you would need to take the object by reference (or pointer). E.g.

void function(ANewType& object); // object passed by reference

This syntax means that any use of object in the function body refers to the actual object which was passed into the function and not a copy. All modifications will modify this object and be visible once the function has completed.

[* The class keyword is also used in template definitions, but that's a different subject.]

How can I change my default database in SQL Server without using MS SQL Server Management Studio?

To do it the GUI way, you need to go edit your login. One of its properties is the default database used for that login. You can find the list of logins under the Logins node under the Security node. Then select your login and right-click and pick Properties. Change the default database and your life will be better!

Note that someone with sysadmin privs needs to be able to login to do this or to run the query from the previous post.

How to convert a Binary String to a base 10 integer in Java

If you're worried about performance, Integer.parseInt() and Math.pow() are too expensive. You can use bit manipulation to do the same thing twice as fast (based on my experience):

final int num = 87;
String biStr = Integer.toBinaryString(num);

System.out.println(" Input Number: " + num + " toBinary "+ biStr);
int dec = binaryStringToDecimal(biStr);
System.out.println("Output Number: " + dec + " toBinary "+Integer.toBinaryString(dec));

Where

int binaryStringToDecimal(String biString){
  int n = biString.length();      
  int decimal = 0;
  for (int d = 0; d < n; d++){
    // append a bit=0 (i.e. shift left) 
    decimal = decimal << 1;

    // if biStr[d] is 1, flip last added bit=0 to 1 
    if (biString.charAt(d) == '1'){
      decimal = decimal | 1; // e.g. dec = 110 | (00)1 = 111
    }
  }
  return decimal;
}

Output:

 Input Number: 87 toBinary 1010111
Output Number: 87 toBinary 1010111

Hide HTML element by id

<style type="text/css">
  #nav-ask{ display:none; }
</style>

How do you post data with a link

We should make everything easier for everyone because you can simply combine JS to PHP Combining PHP and JS is pretty easy.

$house_number = HOUSE_NUMBER;
echo "<script type='text/javascript'>document.forms[0].house_number.value = $house_number; document.forms[0].submit();</script>";

Or a somewhat safer way

$house_number = HOUSE_NUMBER;
echo "<script type='text/javascript'>document.forms[0].house_number.value = " . $house_number . "; document.forms[0].submit();</script>";

CSS: Set Div height to 100% - Pixels

I'm guessing that you are trying to get sticky footer

xml.LoadData - Data at the root level is invalid. Line 1, position 1

Main culprit for this error is logic which determines encoding when converting Stream or byte[] array to .NET string.

Using StreamReader created with 2nd constructor parameter detectEncodingFromByteOrderMarks set to true, will determine proper encoding and create string which does not break XmlDocument.LoadXml method.

public string GetXmlString(string url)
{
    using var stream = GetResponseStream(url);
    using var reader = new StreamReader(stream, true);
    return reader.ReadToEnd(); // no exception on `LoadXml`
}

Common mistake would be to just blindly use UTF8 encoding on the stream or byte[]. Code bellow would produce string that looks valid when inspected in Visual Studio debugger, or copy-pasted somewhere, but it will produce the exception when used with Load or LoadXml if file is encoded differently then UTF8 without BOM.

public string GetXmlString(string url)
{
    byte[] bytes = GetResponseByteArray(url);
    return System.Text.Encoding.UTF8.GetString(bytes); // potentially exception on `LoadXml`
}

Absolute position of an element on the screen using jQuery

For the absolute coordinates of any jquery element I wrote this function, it probably doesnt work for all css position types but maybe its a good start for someone ..

function AbsoluteCoordinates($element) {
    var sTop = $(window).scrollTop();
    var sLeft = $(window).scrollLeft();
    var w = $element.width();
    var h = $element.height();
    var offset = $element.offset(); 
    var $p = $element;
    while(typeof $p == 'object') {
        var pOffset = $p.parent().offset();
        if(typeof pOffset == 'undefined') break;
        offset.left = offset.left + (pOffset.left);
        offset.top = offset.top + (pOffset.top);
        $p = $p.parent();
    }

    var pos = {
          left: offset.left + sLeft,
          right: offset.left + w + sLeft,
          top:  offset.top + sTop,
          bottom: offset.top + h + sTop,
    }
    pos.tl = { x: pos.left, y: pos.top };
    pos.tr = { x: pos.right, y: pos.top };
    pos.bl = { x: pos.left, y: pos.bottom };
    pos.br = { x: pos.right, y: pos.bottom };
    //console.log( 'left: ' + pos.left + ' - right: ' + pos.right +' - top: ' + pos.top +' - bottom: ' + pos.bottom  );
    return pos;
}

git remote add with other SSH port

You can just do this:

git remote add origin ssh://user@host:1234/srv/git/example

1234 is the ssh port being used

Creating csv file with php

@Baba's answer is great. But you don't need to use explode because fputcsv takes an array as a parameter

For instance, if you have a three columns, four lines document, here's a more straight version:

header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="sample.csv"');

$user_CSV[0] = array('first_name', 'last_name', 'age');

// very simple to increment with i++ if looping through a database result 
$user_CSV[1] = array('Quentin', 'Del Viento', 34);
$user_CSV[2] = array('Antoine', 'Del Torro', 55);
$user_CSV[3] = array('Arthur', 'Vincente', 15);

$fp = fopen('php://output', 'wb');
foreach ($user_CSV as $line) {
    // though CSV stands for "comma separated value"
    // in many countries (including France) separator is ";"
    fputcsv($fp, $line, ',');
}
fclose($fp);

How can I get date and time formats based on Culture Info?

You can retrieve the format strings from the CultureInfo DateTimeFormat property, which is a DateTimeFormatInfo instance. This in turn has properties like ShortDatePattern and ShortTimePattern, containing the format strings:

CultureInfo us = new CultureInfo("en-US");
string shortUsDateFormatString = us.DateTimeFormat.ShortDatePattern;
string shortUsTimeFormatString = us.DateTimeFormat.ShortTimePattern;

CultureInfo uk = new CultureInfo("en-GB");
string shortUkDateFormatString = uk.DateTimeFormat.ShortDatePattern;
string shortUkTimeFormatString = uk.DateTimeFormat.ShortTimePattern;

If you simply want to format the date/time using the CultureInfo, pass it in as your IFormatter when converting the DateTime to a string, using the ToString method:

string us = myDate.ToString(new CultureInfo("en-US"));
string uk = myDate.ToString(new CultureInfo("en-GB"));

How to get WooCommerce order details

ONLY FOR WOOCOMMERCE VERSIONS 2.5.x AND 2.6.x

For WOOCOMMERCE VERSION 3.0+ see THIS UPDATE

Here is a custom function I have made, to make the things clear for you, related to get the data of an order ID. You will see all the different RAW outputs you can get and how to get the data you need…

Using print_r() function (or var_dump() function too) allow to output the raw data of an object or an array.

So first I output this data to show the object or the array hierarchy. Then I use different syntax depending on the type of that variable (string, array or object) to output the specific data needed.

IMPORTANT: With $order object you can use most of WC_order or WC_Abstract_Order methods (using the object syntax)…


Here is the code:

function get_order_details($order_id){

    // 1) Get the Order object
    $order = wc_get_order( $order_id );

    // OUTPUT
    echo '<h3>RAW OUTPUT OF THE ORDER OBJECT: </h3>';
    print_r($order);
    echo '<br><br>';
    echo '<h3>THE ORDER OBJECT (Using the object syntax notation):</h3>';
    echo '$order->order_type: ' . $order->order_type . '<br>';
    echo '$order->id: ' . $order->id . '<br>';
    echo '<h4>THE POST OBJECT:</h4>';
    echo '$order->post->ID: ' . $order->post->ID . '<br>';
    echo '$order->post->post_author: ' . $order->post->post_author . '<br>';
    echo '$order->post->post_date: ' . $order->post->post_date . '<br>';
    echo '$order->post->post_date_gmt: ' . $order->post->post_date_gmt . '<br>';
    echo '$order->post->post_content: ' . $order->post->post_content . '<br>';
    echo '$order->post->post_title: ' . $order->post->post_title . '<br>';
    echo '$order->post->post_excerpt: ' . $order->post->post_excerpt . '<br>';
    echo '$order->post->post_status: ' . $order->post->post_status . '<br>';
    echo '$order->post->comment_status: ' . $order->post->comment_status . '<br>';
    echo '$order->post->ping_status: ' . $order->post->ping_status . '<br>';
    echo '$order->post->post_password: ' . $order->post->post_password . '<br>';
    echo '$order->post->post_name: ' . $order->post->post_name . '<br>';
    echo '$order->post->to_ping: ' . $order->post->to_ping . '<br>';
    echo '$order->post->pinged: ' . $order->post->pinged . '<br>';
    echo '$order->post->post_modified: ' . $order->post->post_modified . '<br>';
    echo '$order->post->post_modified_gtm: ' . $order->post->post_modified_gtm . '<br>';
    echo '$order->post->post_content_filtered: ' . $order->post->post_content_filtered . '<br>';
    echo '$order->post->post_parent: ' . $order->post->post_parent . '<br>';
    echo '$order->post->guid: ' . $order->post->guid . '<br>';
    echo '$order->post->menu_order: ' . $order->post->menu_order . '<br>';
    echo '$order->post->post_type: ' . $order->post->post_type . '<br>';
    echo '$order->post->post_mime_type: ' . $order->post->post_mime_type . '<br>';
    echo '$order->post->comment_count: ' . $order->post->comment_count . '<br>';
    echo '$order->post->filter: ' . $order->post->filter . '<br>';
    echo '<h4>THE ORDER OBJECT (again):</h4>';
    echo '$order->order_date: ' . $order->order_date . '<br>';
    echo '$order->modified_date: ' . $order->modified_date . '<br>';
    echo '$order->customer_message: ' . $order->customer_message . '<br>';
    echo '$order->customer_note: ' . $order->customer_note . '<br>';
    echo '$order->post_status: ' . $order->post_status . '<br>';
    echo '$order->prices_include_tax: ' . $order->prices_include_tax . '<br>';
    echo '$order->tax_display_cart: ' . $order->tax_display_cart . '<br>';
    echo '$order->display_totals_ex_tax: ' . $order->display_totals_ex_tax . '<br>';
    echo '$order->display_cart_ex_tax: ' . $order->display_cart_ex_tax . '<br>';
    echo '$order->formatted_billing_address->protected: ' . $order->formatted_billing_address->protected . '<br>';
    echo '$order->formatted_shipping_address->protected: ' . $order->formatted_shipping_address->protected . '<br><br>';
    echo '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - <br><br>';

    // 2) Get the Order meta data
    $order_meta = get_post_meta($order_id);

    echo '<h3>RAW OUTPUT OF THE ORDER META DATA (ARRAY): </h3>';
    print_r($order_meta);
    echo '<br><br>';
    echo '<h3>THE ORDER META DATA (Using the array syntax notation):</h3>';
    echo '$order_meta[_order_key][0]: ' . $order_meta[_order_key][0] . '<br>';
    echo '$order_meta[_order_currency][0]: ' . $order_meta[_order_currency][0] . '<br>';
    echo '$order_meta[_prices_include_tax][0]: ' . $order_meta[_prices_include_tax][0] . '<br>';
    echo '$order_meta[_customer_user][0]: ' . $order_meta[_customer_user][0] . '<br>';
    echo '$order_meta[_billing_first_name][0]: ' . $order_meta[_billing_first_name][0] . '<br><br>';
    echo 'And so on ……… <br><br>';
    echo '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - <br><br>';

    // 3) Get the order items
    $items = $order->get_items();

    echo '<h3>RAW OUTPUT OF THE ORDER ITEMS DATA (ARRAY): </h3>';

    foreach ( $items as $item_id => $item_data ) {

        echo '<h4>RAW OUTPUT OF THE ORDER ITEM NUMBER: '. $item_id .'): </h4>';
        print_r($item_data);
        echo '<br><br>';
        echo 'Item ID: ' . $item_id. '<br>';
        echo '$item_data["product_id"] <i>(product ID)</i>: ' . $item_data['product_id'] . '<br>';
        echo '$item_data["name"] <i>(product Name)</i>: ' . $item_data['name'] . '<br>';

        // Using get_item_meta() method
        echo 'Item quantity <i>(product quantity)</i>: ' . $order->get_item_meta($item_id, '_qty', true) . '<br><br>';
        echo 'Item line total <i>(product quantity)</i>: ' . $order->get_item_meta($item_id, '_line_total', true) . '<br><br>';
        echo 'And so on ……… <br><br>';
        echo '- - - - - - - - - - - - - <br><br>';
    }
    echo '- - - - - - E N D - - - - - <br><br>';
}

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

Usage (if your order ID is 159 for example):

get_order_details(159);

This code is tested and works.

Updated code on November 21, 2016

How to resume Fragment from BackStack if exists

Step 1: Implement an interface with your activity class

public class AuthenticatedMainActivity extends Activity implements FragmentManager.OnBackStackChangedListener{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        .............
        FragmentManager fragmentManager = getFragmentManager();           
        fragmentManager.beginTransaction().add(R.id.frame_container,fragment, "First").addToBackStack(null).commit();
    }

    private void switchFragment(Fragment fragment){            
      FragmentManager fragmentManager = getFragmentManager();
      fragmentManager.beginTransaction()
        .replace(R.id.frame_container, fragment).addToBackStack("Tag").commit();
    }

    @Override
    public void onBackStackChanged() {
    FragmentManager fragmentManager = getFragmentManager();

    System.out.println("@Class: SummaryUser : onBackStackChanged " 
            + fragmentManager.getBackStackEntryCount());

    int count = fragmentManager.getBackStackEntryCount();

    // when a fragment come from another the status will be zero
    if(count == 0){

        System.out.println("again loading user data");

        // reload the page if user saved the profile data

        if(!objPublicDelegate.checkNetworkStatus()){

            objPublicDelegate.showAlertDialog("Warning"
                    , "Please check your internet connection");

        }else {

            objLoadingDialog.show("Refreshing data..."); 

            mNetworkMaster.runUserSummaryAsync();
        }

        // IMPORTANT: remove the current fragment from stack to avoid new instance
        fragmentManager.removeOnBackStackChangedListener(this);

    }// end if
   }       
}

Step 2: When you call the another fragment add this method:

String backStateName = this.getClass().getName();

FragmentManager fragmentManager = getFragmentManager();
fragmentManager.addOnBackStackChangedListener(this); 

Fragment fragmentGraph = new GraphFragment();
Bundle bundle = new Bundle();
bundle.putString("graphTag",  view.getTag().toString());
fragmentGraph.setArguments(bundle);

fragmentManager.beginTransaction()
.replace(R.id.content_frame, fragmentGraph)
.addToBackStack(backStateName)
.commit();

Using FileUtils in eclipse

Open the project's properties---> Java Build Path ---> Libraries tab ---> Add External Jars

will allow you to add jars.

You need to download commonsIO from here.

How can I count the number of elements with same class?

$('#maindivid').find('input .inputclass').length

Does functional programming replace GoF design patterns?

Functional programming does not replace design patterns. Design patterns can not be replaced.

Patterns simply exist; they emerged over time. The GoF book formalized some of them. If new patterns are coming to light as developers use functional programming languages that is exciting stuff, and perhaps there will be books written about them as well.

How do I remove blank elements from an array?

Use reject:

>> cities = ["Kathmandu", "Pokhara", "", "Dharan", "Butwal"].reject{ |e| e.empty? }
=> ["Kathmandu", "Pokhara", "Dharan", "Butwal"]

String contains another two strings

Your b + a is equal "someonedamage", since your d doesn't contain that string, your if statement returns false and doesn't run following parts.

Console.WriteLine(" " + d);
Console.ReadLine();

You can control this more efficient as;

bool b = d.Contains(a) && d.Contains(b);

Here is a DEMO.

How to compare two NSDates: Which is more recent?

NSDate has a compare function.

compare: Returns an NSComparisonResult value that indicates the temporal ordering of the receiver and another given date.

(NSComparisonResult)compare:(NSDate *)anotherDate

Parameters: anotherDate The date with which to compare the receiver. This value must not be nil. If the value is nil, the behavior is undefined and may change in future versions of Mac OS X.

Return Value:

  • If the receiver and anotherDate are exactly equal to each other, NSOrderedSame
  • If the receiver is later in time than anotherDate, NSOrderedDescending
  • If the receiver is earlier in time than anotherDate, NSOrderedAscending.

Find nearest value in numpy array

If you don't want to use numpy this will do it:

def find_nearest(array, value):
    n = [abs(i-value) for i in array]
    idx = n.index(min(n))
    return array[idx]

How to fill a datatable with List<T>

I also had to come up with an alternate solution, as none of the options listed here worked in my case. I was using an IEnumerable and the underlying data was a IEnumerable and the properties couldn't be enumerated. This did the trick:

// remove "this" if not on C# 3.0 / .NET 3.5
public static DataTable ConvertToDataTable<T>(this IEnumerable<T> data)
{
    List<IDataRecord> list = data.Cast<IDataRecord>().ToList();

    PropertyDescriptorCollection props = null;
    DataTable table = new DataTable();
    if (list != null && list.Count > 0)
    {
        props = TypeDescriptor.GetProperties(list[0]);
        for (int i = 0; i < props.Count; i++)
        {
            PropertyDescriptor prop = props[i];
            table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
        }
    }
    if (props != null)
    {
        object[] values = new object[props.Count];
        foreach (T item in data)
        {
            for (int i = 0; i < values.Length; i++)
            {
                values[i] = props[i].GetValue(item) ?? DBNull.Value;
            }
            table.Rows.Add(values);
        }
    }
    return table;
}

How to read a text file in project's root directory?

You can use the following to get the root directory of a website project:

String FilePath;
FilePath = Server.MapPath("/MyWebSite");

Or you can get the base directory like so:

AppDomain.CurrentDomain.BaseDirectory

How to merge rows in a column into one cell in excel?

In simple cases you can use next method which doesn`t require you to create a function or to copy code to several cells:

  1. In any cell write next code

    =Transpose(A1:A9) 
    

Where A1:A9 are cells you would like to merge.

  1. Without leaving the cell press F9

After that, the cell will contain the string:

={A1,A2,A3,A4,A5,A6,A7,A8,A9}

Source: http://www.get-digital-help.com/2011/02/09/concatenate-a-cell-range-without-vba-in-excel/

Update: One part can be ambiguous. Without leaving the cell means having your cell in editor mode. Alternatevly you can press F9 while are in cell editor panel (normaly it can be found above the spreadsheet)

Add to integers in a list

You can append to the end of a list:

foo = [1, 2, 3, 4, 5]
foo.append(4)
foo.append([8,7])    
print(foo)            # [1, 2, 3, 4, 5, 4, [8, 7]]

You can edit items in the list like this:

foo = [1, 2, 3, 4, 5]
foo[3] = foo[3] + 4     
print(foo)            # [1, 2, 3, 8, 5]

Insert integers into the middle of a list:

x = [2, 5, 10]
x.insert(2, 77)
print(x)              # [2, 5, 77, 10]

How do I know the script file name in a Bash script?

echo "$(basename "`test -L ${BASH_SOURCE[0]} \
                   && readlink ${BASH_SOURCE[0]} \
                   || echo ${BASH_SOURCE[0]}`")"

git stash apply version

Just making simple to understand for beginners.

Check your git stash list with below command :

git stash list

And then apply with below command:

git stash apply stash@{n}

For example: I am applying my latest stash(latest is always index {0} on top of the stash list).

 git stash apply stash@{0}

Convert Difference between 2 times into Milliseconds?

Many of the above mentioned solutions might suite different people.
I would like to suggest a slightly modified code than most accepted solution by "MusiGenesis".

DateTime firstTime = DateTime.Parse( TextBox1.Text );
DateTime secondTime = DateTime.Parse( TextBox2.Text );
double milDiff = secondTime.Subtract(firstTime).TotalMilliseconds;

Considerations:
- earlierTime.Subtract(laterTime) you will get a negative value.
- use int milDiff = (int)DateTime.Now.Subtract(StartTime).TotalMilliseconds; if you need integer value instead of double
- Same code can be used to get difference between two Date values and you may get .TotalDays or .TotalHours insteaf of .TotalMilliseconds

what is the difference between OLE DB and ODBC data sources?

According to ADO: ActiveX Data Objects, a book by Jason T. Roff, published by O'Reilly Media in 2001 (excellent diagram here), he says precisely what MOZILLA said.

(directly from page 7 of that book)

  • ODBC provides access only to relational databases
  • OLE DB provides the following features
    • Access to data regardless of its format or location
    • Full access to ODBC data sources and ODBC drivers

So it would seem that OLE DB interacts with SQL-based datasources THRU the ODBC driver layer.

alt text

I'm not 100% sure this image is correct. The two connections I'm not certain about are ADO.NET thru ADO C-api, and OLE DB thru ODBC to SQL-based data source (because in this diagram the author doesn't put OLE DB's access thru ODBC, which I believe is a mistake).

Java: int[] array vs int array[]

There is no difference between these two declarations, and both have the same performance.

Position a CSS background image x pixels from the right?

Its been loong since this question has been asked, but I just ran into this problem and I got it by doing :

background-position:95% 50%;

Parse Json string in C#

json:
[{"ew":"vehicles","hws":["car","van","bike","plane","bus"]},{"ew":"countries","hws":["America","India","France","Japan","South Africa"]}]

c# code: to take only a single value, for example the word "bike".

//res=[{"ew":"vehicles","hws":["car","van","bike","plane","bus"]},{"ew":"countries","hws":["America","India","France","Japan","South Africa"]}]

         dynamic stuff1 = Newtonsoft.Json.JsonConvert.DeserializeObject(res);
         string Text = stuff1[0].hws[2];
         Console.WriteLine(Text);

output:

bike

SOAP client in .NET - references or examples?

If you can get it to run in a browser then something as simple as this would work

var webRequest = WebRequest.Create(@"http://webservi.se/year/getCurrentYear");

using (var response = webRequest.GetResponse())
{
    using (var rd = new StreamReader(response.GetResponseStream()))
    {
        var soapResult = rd.ReadToEnd();
    }
}

What's wrong with foreign keys?

Foreign keys are essential to any relational database model.

JQuery Ajax POST in Codeigniter

The question has already been answered but I thought I would also let you know that rather than using the native PHP $_POST I reccomend you use the CodeIgniter input class so your controller code would be

function post_action()
{   
    if($this->input->post('textbox') == "")
    {
        $message = "You can't send empty text";
    }
    else
    {
        $message = $this->input->post('textbox');
    }
    echo $message;
}

How to loop through a plain JavaScript object with the objects as members?

Exotic one - deep traverse

JSON.stringify(validation_messages,(field,value)=>{
  if(!field) return value;
  
  // ... your code
  
  return value;
})

In this solution we use replacer which allows to deep traverse whole object and nested objects - on each level you will get all fields and values. If you need to get full path to each field look here

_x000D_
_x000D_
var validation_messages = {
    "key_1": {
        "your_name": "jimmy",
        "your_msg": "hello world"
    },
    "key_2": {
        "your_name": "billy",
        "your_msg": "foo equals bar",
        "deep": {
          "color": "red",
          "size": "10px"
        }
    }
}

JSON.stringify(validation_messages,(field,value)=>{
  if(!field) return value;
  
  console.log(`key: ${field.padEnd(11)} - value: ${value}`);
  
  return value;
})
_x000D_
_x000D_
_x000D_

Capture Video of Android's Screen

It is possible to record screen video directly from your phone or tablet if your device is rooted. I'm working on the SCR Screen Recorder app. To the best of my knowledge this is the only app supporting Tegra devices (including Nexus 7) and Android 4.2. At the moment the app records between 9-18fps depending on device but I'm working to improve that. SCR Screen Recorder is still in beta testing phase so feel free to test it and give feedback.

How do function pointers in C work?

Function pointers become easy to declare once you have the basic declarators:

  • id: ID: ID is a
  • Pointer: *D: D pointer to
  • Function: D(<parameters>): D function taking <parameters> returning

While D is another declarator built using those same rules. In the end, somewhere, it ends with ID (see below for an example), which is the name of the declared entity. Let's try to build a function taking a pointer to a function taking nothing and returning int, and returning a pointer to a function taking a char and returning int. With type-defs it's like this

typedef int ReturnFunction(char);
typedef int ParameterFunction(void);
ReturnFunction *f(ParameterFunction *p);

As you see, it's pretty easy to build it up using typedefs. Without typedefs, it's not hard either with the above declarator rules, applied consistently. As you see i missed out the part the pointer points to, and the thing the function returns. That's what appears at the very left of the declaration, and is not of interest: It's added at the end if one built up the declarator already. Let's do that. Building it up consistently, first wordy - showing the structure using [ and ]:

function taking 
    [pointer to [function taking [void] returning [int]]] 
returning
    [pointer to [function taking [char] returning [int]]]

As you see, one can describe a type completely by appending declarators one after each other. Construction can be done in two ways. One is bottom-up, starting with the very right thing (leaves) and working the way through up to the identifier. The other way is top-down, starting at the identifier, working the way down to the leaves. I'll show both ways.

Bottom Up

Construction starts with the thing at the right: The thing returned, which is the function taking char. To keep the declarators distinct, i'm going to number them:

D1(char);

Inserted the char parameter directly, since it's trivial. Adding a pointer to declarator by replacing D1 by *D2. Note that we have to wrap parentheses around *D2. That can be known by looking up the precedence of the *-operator and the function-call operator (). Without our parentheses, the compiler would read it as *(D2(char p)). But that would not be a plain replace of D1 by *D2 anymore, of course. Parentheses are always allowed around declarators. So you don't make anything wrong if you add too much of them, actually.

(*D2)(char);

Return type is complete! Now, let's replace D2 by the function declarator function taking <parameters> returning, which is D3(<parameters>) which we are at now.

(*D3(<parameters>))(char)

Note that no parentheses are needed, since we want D3 to be a function-declarator and not a pointer declarator this time. Great, only thing left is the parameters for it. The parameter is done exactly the same as we've done the return type, just with char replaced by void. So i'll copy it:

(*D3(   (*ID1)(void)))(char)

I've replaced D2 by ID1, since we are finished with that parameter (it's already a pointer to a function - no need for another declarator). ID1 will be the name of the parameter. Now, i told above at the end one adds the type which all those declarator modify - the one appearing at the very left of every declaration. For functions, that becomes the return type. For pointers the pointed to type etc... It's interesting when written down the type, it will appear in the opposite order, at the very right :) Anyway, substituting it yields the complete declaration. Both times int of course.

int (*ID0(int (*ID1)(void)))(char)

I've called the identifier of the function ID0 in that example.

Top Down

This starts at the identifier at the very left in the description of the type, wrapping that declarator as we walk our way through the right. Start with function taking <parameters> returning

ID0(<parameters>)

The next thing in the description (after "returning") was pointer to. Let's incorporate it:

*ID0(<parameters>)

Then the next thing was functon taking <parameters> returning. The parameter is a simple char, so we put it in right away again, since it's really trivial.

(*ID0(<parameters>))(char)

Note the parentheses we added, since we again want that the * binds first, and then the (char). Otherwise it would read function taking <parameters> returning function .... Noes, functions returning functions aren't even allowed.

Now we just need to put <parameters>. I will show a short version of the deriveration, since i think you already by now have the idea how to do it.

pointer to: *ID1
... function taking void returning: (*ID1)(void)

Just put int before the declarators like we did with bottom-up, and we are finished

int (*ID0(int (*ID1)(void)))(char)

The nice thing

Is bottom-up or top-down better? I'm used to bottom-up, but some people may be more comfortable with top-down. It's a matter of taste i think. Incidentally, if you apply all the operators in that declaration, you will end up getting an int:

int v = (*ID0(some_function_pointer))(some_char);

That is a nice property of declarations in C: The declaration asserts that if those operators are used in an expression using the identifier, then it yields the type on the very left. It's like that for arrays too.

Hope you liked this little tutorial! Now we can link to this when people wonder about the strange declaration syntax of functions. I tried to put as little C internals as possible. Feel free to edit/fix things in it.

Go / golang time.Now().UnixNano() convert to milliseconds?

At https://github.com/golang/go/issues/44196 randall77 suggested

time.Now().Sub(time.Unix(0,0)).Milliseconds()

which exploits the fact that Go's time.Duration already have Milliseconds method.

Apache Name Virtual Host with SSL

The VirtualHost would look like this:

NameVirtualHost IP_Address:443

<VirtualHost IP_Address:443>
    SSLEngine on
    SSLCertificateFile /etc/pki/tls/certs/ca.crt    # Where "ca" is the name of the Certificate
    SSLCertificateKeyFile /etc/pki/tls/private/ca.key
    ServerAdmin webmaster@domain_name.com
    DocumentRoot /var/www/html
    ServerName www.domain_name.com
    ErrorLog logs/www.domain_name.com-error_log
    CustomLog logs/www.domain_name.com-access_log common
</VirtualHost>

What is the most appropriate way to store user settings in Android application

Okay; it's been a while since the answer is kind-of mixed, but here's a few common answers. I researched this like crazy and it was hard to build a good answer

  1. The MODE_PRIVATE method is considered generally safe, if you assume that the user didn't root the device. Your data is stored in plain text in a part of the file system that can only be accessed by the original program. This makings grabbing the password with another app on a rooted device easy. Then again, do you want to support rooted devices?

  2. AES is still the best encryption you can do. Remember to look this up if you are starting a new implementation if it's been a while since I posted this. The largest issue with this is "What to do with the encryption key?"

So, now we are at the "What to do with the key?" portion. This is the hard part. Getting the key turns out to be not that bad. You can use a key derivation function to take some password and make it a pretty secure key. You do get into issues like "how many passes do you do with PKFDF2?", but that's another topic

  1. Ideally, you store the AES key off the device. You have to figure out a good way to retrieve the key from the server safely, reliably, and securely though

  2. You have a login sequence of some sort (even the original login sequence you do for remote access). You can do two runs of your key generator on the same password. How this works is that you derive the key twice with a new salt and a new secure initialization vector. You store one of those generated passwords on the device, and you use the second password as the AES key.

When you log in, you re-derive the key on the local login and compare it to the stored key. Once that is done, you use derive key #2 for AES.

  1. Using the "generally safe" approach, you encrypt the data using AES and store the key in MODE_PRIVATE. This is recommended by a recent-ish Android blog post. Not incredibly secure, but way better for some people over plain text

You can do a lot of variations of these. For example, instead of a full login sequence, you can do a quick PIN (derived). The quick PIN might not be as secure as a full login sequence, but it's many times more secure than plain text

How to resolve TypeError: Cannot convert undefined or null to object

I solved the same problem in a React Native project. I solved it using this.

let data = snapshot.val();
if(data){
  let items = Object.values(data);
}
else{
  //return null
}

Raw SQL Query without DbSet - Entity Framework Core

I used Dapper to bypass this constraint of Entity framework Core.

IDbConnection.Query

is working with either sql query or stored procedure with multiple parameters. By the way it's a bit faster (see benchmark tests )

Dapper is easy to learn. It took 15 minutes to write and run stored procedure with parameters. Anyway you may use both EF and Dapper. Below is an example:

 public class PodborsByParametersService
{
    string _connectionString = null;


    public PodborsByParametersService(string connStr)
    {
        this._connectionString = connStr;

    }

    public IList<TyreSearchResult> GetTyres(TyresPodborView pb,bool isPartner,string partnerId ,int pointId)
    {

        string sqltext  "spGetTyresPartnerToClient";

        var p = new DynamicParameters();
        p.Add("@PartnerID", partnerId);
        p.Add("@PartnerPointID", pointId);

        using (IDbConnection db = new SqlConnection(_connectionString))
        {
            return db.Query<TyreSearchResult>(sqltext, p,null,true,null,CommandType.StoredProcedure).ToList();
        }


        }
}

Compiling dynamic HTML strings from database

You can use

ng-bind-html https://docs.angularjs.org/api/ng/service/$sce

directive to bind html dynamically. However you have to get the data via $sce service.

Please see the live demo at http://plnkr.co/edit/k4s3Bx

var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope,$sce) {
    $scope.getHtml=function(){
   return $sce.trustAsHtml("<b>Hi Rupesh hi <u>dfdfdfdf</u>!</b>sdafsdfsdf<button>dfdfasdf</button>");
   }
});

  <body ng-controller="MainCtrl">
<span ng-bind-html="getHtml()"></span>
  </body>

Content is not allowed in Prolog SAXParserException

This error can come if there is validation error either in your wsdl or xsd file. For instance I too got the same issue while running wsdl2java to convert my wsdl file to generate the client. In one of my xsd it was defined as below

<xs:import schemaLocation="" namespace="http://MultiChoice.PaymentService/DataContracts" />

Where the schemaLocation was empty. By providing the proper data in schemaLocation resolved my problem.

<xs:import schemaLocation="multichoice.paymentservice.DataContracts.xsd" namespace="http://MultiChoice.PaymentService/DataContracts" />

Globally catch exceptions in a WPF application?

Use the Application.DispatcherUnhandledException Event. See this question for a summary (see Drew Noakes' answer).

Be aware that there'll be still exceptions which preclude a successful resuming of your application, like after a stack overflow, exhausted memory, or lost network connectivity while you're trying to save to the database.

How to send a JSON object over Request with Android?

public void postData(String url,JSONObject obj) {
    // Create a new HttpClient and Post Header

    HttpParams myParams = new BasicHttpParams();
    HttpConnectionParams.setConnectionTimeout(myParams, 10000);
    HttpConnectionParams.setSoTimeout(myParams, 10000);
    HttpClient httpclient = new DefaultHttpClient(myParams );
    String json=obj.toString();

    try {

        HttpPost httppost = new HttpPost(url.toString());
        httppost.setHeader("Content-type", "application/json");

        StringEntity se = new StringEntity(obj.toString()); 
        se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
        httppost.setEntity(se); 

        HttpResponse response = httpclient.execute(httppost);
        String temp = EntityUtils.toString(response.getEntity());
        Log.i("tag", temp);


    } catch (ClientProtocolException e) {

    } catch (IOException e) {
    }
}

Combining "LIKE" and "IN" for SQL Server

You need multiple LIKE clauses connected by OR.

SELECT * FROM table WHERE 
column LIKE 'Text%' OR 
column LIKE 'Link%' OR 
column LIKE 'Hello%' OR 
column LIKE '%World%' OR 

MVC3 DropDownListFor - a simple example?

You should do like this:

@Html.DropDownListFor(m => m.ContribType, 
                new SelectList(Model.ContribTypeOptions, 
                               "ContribId", "Value"))

Where:

m => m.ContribType

is a property where the result value will be.

Can I have onScrollListener for a ScrollView?

you can define a custom ScrollView class, & add an interface be called when scrolling like this:

public class ScrollChangeListenerScrollView extends HorizontalScrollView {


private MyScrollListener mMyScrollListener;

public ScrollChangeListenerScrollView(Context context) {
    super(context);
}

public ScrollChangeListenerScrollView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public ScrollChangeListenerScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
}


public void setOnMyScrollListener(MyScrollListener myScrollListener){
    this.mMyScrollListener = myScrollListener;
}


@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
    super.onScrollChanged(l, t, oldl, oldt);
    if(mMyScrollListener!=null){
        mMyScrollListener.onScrollChange(this,l,t,oldl,oldt);
    }

}

public interface MyScrollListener {
    void onScrollChange(View view,int scrollX,int scrollY,int oldScrollX, int oldScrollY);
}

}

Simple way to convert datarow array to datatable

DataTable dt = myDataRowCollection.CopyToDataTable<DataRow>();

Left-pad printf with spaces

I use this function to indent my output (for example to print a tree structure). The indent is the number of spaces before the string.

void print_with_indent(int indent, char * string)
{
    printf("%*s%s", indent, "", string);
}

python: SyntaxError: EOL while scanning string literal

I faced a similar problem. I had a string which contained path to a folder in Windows e.g. C:\Users\ The problem is that \ is an escape character and so in order to use it in strings you need to add one more \.

Incorrect: C:\Users\

Correct: C:\\\Users\\\

How to check if a string is null in python

Try this:

if cookie and not cookie.isspace():
    # the string is non-empty
else:
    # the string is empty

The above takes in consideration the cases where the string is None or a sequence of white spaces.

Extract a part of the filepath (a directory) in Python

All you need is parent part if you use pathlib.

from pathlib import Path
p = Path(r'C:\Program Files\Internet Explorer\iexplore.exe')
print(p.parent) 

Will output:

C:\Program Files\Internet Explorer    

Case you need all parts (already covered in other answers) use parts:

p = Path(r'C:\Program Files\Internet Explorer\iexplore.exe')
print(p.parts) 

Then you will get a list:

('C:\\', 'Program Files', 'Internet Explorer', 'iexplore.exe')

Saves tone of time.

Stop absolutely positioned div from overlapping text

You should set z-index to absolutely positioned div that is greater than to relative div.

Something like that

<div style="position: relative; width:600px; z-index: 10;">
    <p>Content of unknown length</p>
    <div>Content of unknown height</div>
    <div class="btn" style="position: absolute; right: 0; bottom: 0; width: 200px; height: 100px; z-index: 20;"></div>
</div>

z-index sets layers positioning in depth of page.

Or you may use floating to show all text of unkown length. But in this case you could not absolutely position your div

<div style="position: relative; width:600px;">
  <div class="btn" style="float: right; width: 200px; height: 100px;"></div>
  <p>Content of unknown length Content of unknown length Content of unknown length Content of unknown length Content of unknown length Content of unknown length Content of unknown length Content of unknown length</p>
  <div>Content of unknown height</div>
  <div class="btn" style="position: absolute; right: 0; bottom: 0; width: 200px; height: 100px;"></div>
</div>?

Attempt to write a readonly database - Django w/ SELinux error

This issue is caused by SELinux. After setting file ownership just as you did, I hit this issue. The audit2why(1) tool can be used to diagnose SELinux denials from the log:

(django)[f22-4:www/django/demo] ftweedal% sudo audit2why -a
type=AVC msg=audit(1437490152.208:407): avc:  denied  { write }
      for  pid=20330 comm="httpd" name="db.sqlite3" dev="dm-1" ino=52036
      scontext=system_u:system_r:httpd_t:s0
      tcontext=unconfined_u:object_r:httpd_sys_content_t:s0
      tclass=file permissive=0
    Was caused by:
    The boolean httpd_unified was set incorrectly. 
    Description:
    Allow httpd to unified

    Allow access by executing:
    # setsebool -P httpd_unified 1

Sure enough, running sudo setsebool -P httpd_unified 1 resolved the issue.

Looking into what httpd_unified is for, I came across a fedora-selinux-list post which explains:

This Boolean is off by default, turning it on will allow all httpd executables to have full access to all content labeled with a http file context. Leaving it off makes sure that one httpd service can not interfere with another.

So turning on httpd_unified lets you circumvent the default behaviour that prevents multiple httpd instances on the same server - all running as user apache - messing with each others' stuff.

In my case, I am only running one httpd, so it was fine for me to turn on httpd_unified. If you cannot do this, I suppose some more fine-grained labelling is needed.

Is it possible to set an object to null?

While it is true that an object cannot be "empty/null" in C++, in C++17, we got std::optional to express that intent.

Example use:

std::optional<int> v1;      // "empty" int
std::optional<int> v2(3);   // Not empty, "contains a 3"

You can then check if the optional contains a value with

v1.has_value(); // false

or

if(v2) {
    // You get here if v2 is not empty
}

A plain int (or any type), however, can never be "null" or "empty" (by your definition of those words) in any useful sense. Think of std::optional as a container in this regard.

If you don't have a C++17 compliant compiler at hand, you can use boost.optional instead. Some pre-C++17 compilers also offer std::experimental::optional, which will behave at least close to the actual std::optional afaik. Check your compiler's manual for details.

Entity Framework Refresh context?

Refreshing db context with Reload is not recommended way due to performance loses. It is good enough and the best practice to initialize a new instance of the dbcontext before each operation executed. It also provide you a refreshed up to date context for each operation.

using (YourContext ctx = new YourContext())
{
   //Your operations
}

Spring Security with roles and permissions

This is the simplest way to do it. Allows for group authorities, as well as user authorities.

-- Postgres syntax

create table users (
  user_id serial primary key,
  enabled boolean not null default true,
  password text not null,
  username citext not null unique
);

create index on users (username);

create table groups (
  group_id serial primary key,
  name citext not null unique
);

create table authorities (
  authority_id serial primary key,
  authority citext not null unique
);

create table user_authorities (
  user_id int references users,
  authority_id int references authorities,
  primary key (user_id, authority_id)
);

create table group_users (
  group_id int references groups,
  user_id int referenecs users,
  primary key (group_id, user_id)
);

create table group_authorities (
  group_id int references groups,
  authority_id int references authorities,
  primary key (group_id, authority_id)
);

Then in META-INF/applicationContext-security.xml

<beans:bean class="org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder" id="passwordEncoder" />

<authentication-manager>
    <authentication-provider>

        <jdbc-user-service
                data-source-ref="dataSource"

                users-by-username-query="select username, password, enabled from users where username=?"

                authorities-by-username-query="select users.username, authorities.authority from users join user_authorities using(user_id) join authorities using(authority_id) where users.username=?"

                group-authorities-by-username-query="select groups.id, groups.name, authorities.authority from users join group_users using(user_id) join groups using(group_id) join group_authorities using(group_id) join authorities using(authority_id) where users.username=?"

                />

          <password-encoder ref="passwordEncoder" />

    </authentication-provider>
</authentication-manager>

Javascript Regex: How to put a variable inside a regular expression?

You can create regular expressions in JS in one of two ways:

  1. Using regular expression literal - /ab{2}/g
  2. Using the regular expression constructor - new RegExp("ab{2}", "g") .

Regular expression literals are constant, and can not be used with variables. This could be achieved using the constructor. The stracture of the RegEx constructor is

new RegExp(regularExpressionString, modifiersString)

You can embed variables as part of the regularExpressionString. For example,

var pattern="cd"
var repeats=3
new RegExp(`${pattern}{${repeats}}`, "g") 

This will match any appearance of the pattern cdcdcd.

How to get milliseconds from LocalDateTime in Java 8

To avoid ZoneId you can do:

LocalDateTime date = LocalDateTime.of(1970, 1, 1, 0, 0);

System.out.println("Initial Epoch (TimeInMillis): " + date.toInstant(ZoneOffset.ofTotalSeconds(0)).toEpochMilli());

Getting 0 as value, that's right!

LINQ Group By into a Dictionary Object

For @atari2600, this is what the answer would look like using ToLookup in lambda syntax:

var x = listOfCustomObjects
    .GroupBy(o => o.PropertyName)
    .ToLookup(customObject => customObject);

Basically, it takes the IGrouping and materializes it for you into a dictionary of lists, with the values of PropertyName as the key.

How to use GROUP_CONCAT in a CONCAT in MySQL

SELECT ID, GROUP_CONCAT(CONCAT_WS(':', NAME, VALUE) SEPARATOR ',') AS Result 
FROM test GROUP BY ID

getString Outside of a Context or Activity

It's better to use something like this without context and activity:

Resources.getSystem().getString(R.string.my_text)

get url content PHP

original answer moved to this topic .

In Java, how do I check if a string contains a substring (ignoring case)?

I also favor the RegEx solution. The code will be much cleaner. I would hesitate to use toLowerCase() in situations where I knew the strings were going to be large, since strings are immutable and would have to be copied. Also, the matches() solution might be confusing because it takes a regular expression as an argument (searching for "Need$le" cold be problematic).

Building on some of the above examples:

public boolean containsIgnoreCase( String haystack, String needle ) {
  if(needle.equals(""))
    return true;
  if(haystack == null || needle == null || haystack .equals(""))
    return false; 

  Pattern p = Pattern.compile(needle,Pattern.CASE_INSENSITIVE+Pattern.LITERAL);
  Matcher m = p.matcher(haystack);
  return m.find();
}

example call: 

String needle = "Need$le";
String haystack = "This is a haystack that might have a need$le in it.";
if( containsIgnoreCase( haystack, needle) ) {
  System.out.println( "Found " + needle + " within " + haystack + "." );
}

(Note: you might want to handle NULL and empty strings differently depending on your needs. I think they way I have it is closer to the Java spec for strings.)

Speed critical solutions could include iterating through the haystack character by character looking for the first character of the needle. When the first character is matched (case insenstively), begin iterating through the needle character by character, looking for the corresponding character in the haystack and returning "true" if all characters get matched. If a non-matched character is encountered, resume iteration through the haystack at the next character, returning "false" if a position > haystack.length() - needle.length() is reached.

How to extract table as text from the PDF using Python?

This answer is for anyone encountering pdfs with images and needing to use OCR. I could not find a workable off-the-shelf solution; nothing that gave me the accuracy I needed.

Here are the steps I found to work.

  1. Use pdfimages from https://poppler.freedesktop.org/ to turn the pages of the pdf into images.

  2. Use Tesseract to detect rotation and ImageMagick mogrify to fix it.

  3. Use OpenCV to find and extract tables.

  4. Use OpenCV to find and extract each cell from the table.

  5. Use OpenCV to crop and clean up each cell so that there is no noise that will confuse OCR software.

  6. Use Tesseract to OCR each cell.

  7. Combine the extracted text of each cell into the format you need.

I wrote a python package with modules that can help with those steps.

Repo: https://github.com/eihli/image-table-ocr

Docs & Source: https://eihli.github.io/image-table-ocr/pdf_table_extraction_and_ocr.html

Some of the steps don't require code, they take advantage of external tools like pdfimages and tesseract. I'll provide some brief examples for a couple of the steps that do require code.

  1. Finding tables:

This link was a good reference while figuring out how to find tables. https://answers.opencv.org/question/63847/how-to-extract-tables-from-an-image/

import cv2

def find_tables(image):
    BLUR_KERNEL_SIZE = (17, 17)
    STD_DEV_X_DIRECTION = 0
    STD_DEV_Y_DIRECTION = 0
    blurred = cv2.GaussianBlur(image, BLUR_KERNEL_SIZE, STD_DEV_X_DIRECTION, STD_DEV_Y_DIRECTION)
    MAX_COLOR_VAL = 255
    BLOCK_SIZE = 15
    SUBTRACT_FROM_MEAN = -2

    img_bin = cv2.adaptiveThreshold(
        ~blurred,
        MAX_COLOR_VAL,
        cv2.ADAPTIVE_THRESH_MEAN_C,
        cv2.THRESH_BINARY,
        BLOCK_SIZE,
        SUBTRACT_FROM_MEAN,
    )
    vertical = horizontal = img_bin.copy()
    SCALE = 5
    image_width, image_height = horizontal.shape
    horizontal_kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (int(image_width / SCALE), 1))
    horizontally_opened = cv2.morphologyEx(img_bin, cv2.MORPH_OPEN, horizontal_kernel)
    vertical_kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (1, int(image_height / SCALE)))
    vertically_opened = cv2.morphologyEx(img_bin, cv2.MORPH_OPEN, vertical_kernel)

    horizontally_dilated = cv2.dilate(horizontally_opened, cv2.getStructuringElement(cv2.MORPH_RECT, (40, 1)))
    vertically_dilated = cv2.dilate(vertically_opened, cv2.getStructuringElement(cv2.MORPH_RECT, (1, 60)))

    mask = horizontally_dilated + vertically_dilated
    contours, hierarchy = cv2.findContours(
        mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE,
    )

    MIN_TABLE_AREA = 1e5
    contours = [c for c in contours if cv2.contourArea(c) > MIN_TABLE_AREA]
    perimeter_lengths = [cv2.arcLength(c, True) for c in contours]
    epsilons = [0.1 * p for p in perimeter_lengths]
    approx_polys = [cv2.approxPolyDP(c, e, True) for c, e in zip(contours, epsilons)]
    bounding_rects = [cv2.boundingRect(a) for a in approx_polys]

    # The link where a lot of this code was borrowed from recommends an
    # additional step to check the number of "joints" inside this bounding rectangle.
    # A table should have a lot of intersections. We might have a rectangular image
    # here though which would only have 4 intersections, 1 at each corner.
    # Leaving that step as a future TODO if it is ever necessary.
    images = [image[y:y+h, x:x+w] for x, y, w, h in bounding_rects]
    return images
  1. Extract cells from table.

This is very similar to 2, so I won't include all the code. The part I will reference will be in sorting the cells.

We want to identify the cells from left-to-right, top-to-bottom.

We’ll find the rectangle with the most top-left corner. Then we’ll find all of the rectangles that have a center that is within the top-y and bottom-y values of that top-left rectangle. Then we’ll sort those rectangles by the x value of their center. We’ll remove those rectangles from the list and repeat.

def cell_in_same_row(c1, c2):
    c1_center = c1[1] + c1[3] - c1[3] / 2
    c2_bottom = c2[1] + c2[3]
    c2_top = c2[1]
    return c2_top < c1_center < c2_bottom

orig_cells = [c for c in cells]
rows = []
while cells:
    first = cells[0]
    rest = cells[1:]
    cells_in_same_row = sorted(
        [
            c for c in rest
            if cell_in_same_row(c, first)
        ],
        key=lambda c: c[0]
    )

    row_cells = sorted([first] + cells_in_same_row, key=lambda c: c[0])
    rows.append(row_cells)
    cells = [
        c for c in rest
        if not cell_in_same_row(c, first)
    ]

# Sort rows by average height of their center.
def avg_height_of_center(row):
    centers = [y + h - h / 2 for x, y, w, h in row]
    return sum(centers) / len(centers)

rows.sort(key=avg_height_of_center)

How to call a web service from jQuery

EDIT:

The OP was not looking to use cross-domain requests, but jQuery supports JSONP as of v1.5. See jQuery.ajax(), specificically the crossDomain parameter.

The regular jQuery Ajax requests will not work cross-site, so if you want to query a remote RESTful web service, you'll probably have to make a proxy on your server and query that with a jQuery get request. See this site for an example.

If it's a SOAP web service, you may want to try the jqSOAPClient plugin.

TypeError: only length-1 arrays can be converted to Python scalars while plot showing

The error "only length-1 arrays can be converted to Python scalars" is raised when the function expects a single value but you pass an array instead.

If you look at the call signature of np.int, you'll see that it accepts a single value, not an array. In general, if you want to apply a function that accepts a single element to every element in an array, you can use np.vectorize:

import numpy as np
import matplotlib.pyplot as plt

def f(x):
    return np.int(x)
f2 = np.vectorize(f)
x = np.arange(1, 15.1, 0.1)
plt.plot(x, f2(x))
plt.show()

You can skip the definition of f(x) and just pass np.int to the vectorize function: f2 = np.vectorize(np.int).

Note that np.vectorize is just a convenience function and basically a for loop. That will be inefficient over large arrays. Whenever you have the possibility, use truly vectorized functions or methods (like astype(int) as @FFT suggests).

jQuery position DIV fixed at top on scroll

instead of doing it like that, why not just make the flyout position:fixed, top:0; left:0; once your window has scrolled pass a certain height:

jQuery

  $(window).scroll(function(){
      if ($(this).scrollTop() > 135) {
          $('#task_flyout').addClass('fixed');
      } else {
          $('#task_flyout').removeClass('fixed');
      }
  });

css

.fixed {position:fixed; top:0; left:0;}

Example

GIT_DISCOVERY_ACROSS_FILESYSTEM problem when working with terminal and MacFusion

I got this error until I realized that I hadn't intialized a Git repository in that folder, on a mounted vagrant machine.

So I typed git init and then git worked.

Remove all special characters except space from a string using JavaScript

I tried Seagul's very creative solution, but found it treated numbers also as special characters, which did not suit my needs. So here is my (failsafe) tweak of Seagul's solution...

//return true if char is a number
function isNumber (text) {
  if(text) {
    var reg = new RegExp('[0-9]+$');
    return reg.test(text);
  }
  return false;
}

function removeSpecial (text) {
  if(text) {
    var lower = text.toLowerCase();
    var upper = text.toUpperCase();
    var result = "";
    for(var i=0; i<lower.length; ++i) {
      if(isNumber(text[i]) || (lower[i] != upper[i]) || (lower[i].trim() === '')) {
        result += text[i];
      }
    }
    return result;
  }
  return '';
}

Print current call stack from a method in Python code

import traceback
traceback.print_stack()

How to update cursor limit for ORA-01000: maximum open cursors exceed

Assuming that you are using a spfile to start the database

alter system set open_cursors = 1000 scope=both;

If you are using a pfile instead, you can change the setting for the running instance

alter system set open_cursors = 1000 

You would also then need to edit the parameter file to specify the new open_cursors setting. It would generally be a good idea to restart the database shortly thereafter to make sure that the parameter file change works as expected (it's highly annoying to discover months later the next time that you reboot the database that some parameter file change than no one remembers wasn't done correctly).

I'm also hoping that you are certain that you actually need more than 300 open cursors per session. A large fraction of the time, people that are adjusting this setting actually have a cursor leak and they are simply trying to paper over the bug rather than addressing the root cause.

How to reset selected file with input tag file type in Angular 2?

Short version Plunker:

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

@Component({
  selector: 'my-app',
  template: `
      <input #myInput type="file" placeholder="File Name" name="filename">
      <button (click)="myInput.value = ''">Reset</button>
  `
})
export class AppComponent {


}

And i think more common case is to not using button but do reset automatically. Angular Template statements support chaining expressions so Plunker:

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

@Component({
  selector: 'my-app',
  template: `
      <input #myInput type="file" (change)="onChange(myInput.value, $event); myInput.value = ''" placeholder="File Name" name="filename">
  `
})
export class AppComponent {

  onChange(files, event) {
    alert( files );
    alert( event.target.files[0].name );
  }

}

And interesting link about why there is no recursion on value change.