Programs & Examples On #Datacontext

A DataContext is used in WPF, Silverlight and various other .NET technologies. When used with WPF or Silverlight, a DataContext is an object holding the data that the form (or page in case of Silverlight) uses as a display source for its UI elements.

WPF Databinding: How do I access the "parent" data context?

This will also work:

<Hyperlink Command="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl},
                             Path=DataContext.AllowItemCommand}" />

ListView will inherit its DataContext from Window, so it's available at this point, too.
And since ListView, just like similar controls (e. g. Gridview, ListBox, etc.), is a subclass of ItemsControl, the Binding for such controls will work perfectly.

What does (function($) {})(jQuery); mean?

Actually, this example helped me to understand what does (function($) {})(jQuery); mean.

Consider this:

// Clousure declaration (aka anonymous function)
var f = function(x) { return x*x; };
// And use of it
console.log( f(2) ); // Gives: 4

// An inline version (immediately invoked)
console.log( (function(x) { return x*x; })(2) ); // Gives: 4

And now consider this:

  • jQuery is a variable holding jQuery object.
  • $ is a variable name like any other (a, $b, a$b etc.) and it doesn't have any special meaning like in PHP.

Knowing that we can take another look at our example:

var $f = function($) { return $*$; };
var jQuery = 2;
console.log( $f(jQuery) ); // Gives: 4

// An inline version (immediately invoked)
console.log( (function($) { return $*$; })(jQuery) ); // Gives: 4

How to transfer some data to another Fragment?

From Activity Class:

Send the data using bundle arguments to the fragment and load the fragment

   Fragment fragment = new myFragment();
   Bundle bundle = new Bundle();
   bundle.putString("pName", personName);
   bundle.putString("pEmail", personEmail);
   bundle.putString("pId", personId);
   fragment.setArguments(bundle);

   getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                    fragment).commit();

From myFragment Class:

Get the arguments from the bundle and set them to xml

    Bundle arguments = getArguments();
    String personName = arguments.getString("pName");
    String personEmail = arguments.getString("pEmail");
    String personId = arguments.getString("pId");

    nameTV = v.findViewById(R.id.name);
    emailTV = v.findViewById(R.id.email);
    idTV = v.findViewById(R.id.id);

    nameTV.setText("Name: "+ personName);
    emailTV.setText("Email: "+ personEmail);
    idTV.setText("ID: "+ personId);

CodeIgniter - accessing $config variable in view

Your controller should collect all the information from databases, configs, etc. There are many good reasons to stick to this. One good reason is that this will allow you to change the source of that information quite easily and not have to make any changes to your views.

Javascript: Extend a Function

2017+ solution

The idea of function extensions comes from functional paradigm, which is natively supported since ES6:

function init(){
    doSomething();
}

// extend.js

init = (f => u => { f(u)
    doSomethingHereToo();
})(init);

init();

As per @TJCrowder's concern about stack dump, the browsers handle the situation much better today. If you save this code into test.html and run it, you get

test.html:3 Uncaught ReferenceError: doSomething is not defined
    at init (test.html:3)
    at test.html:8
    at test.html:12

Line 12: the init call, Line 8: the init extension, Line 3: the undefined doSomething() call.

Note: Much respect to veteran T.J. Crowder, who kindly answered my question many years ago, when I was a newbie. After the years, I still remember the respectfull attitude and I try to follow the good example.

JOptionPane - input dialog box program

After that you have to parse the results. Suppose results are in integers, then

int testint1 = Integer.parse(test1);

Similarly others should be parsed. Now the results should be checked for two higher marks in them, by using if statement After that take out the average.

Remove padding from columns in Bootstrap 3

<div class="col-md-12">
<h2>OntoExplorer<span style="color:#b92429">.</span></h2>

<div class="col-md-4">
    <div class="widget row">
        <div class="widget-header">
            <h3>Dimensions</h3>
        </div>

        <div class="widget-content" id="">
            <div id='jqxWidget'>
                <div style="clear:both;margin-bottom:20px;" id="listBoxA"></div>
                <div style="clear:both;" id="listBoxB"></div>

            </div>
        </div>
    </div>
</div>

<div class="col-md-8">
    <div class="widget row">
        <div class="widget-header">
            <h3>Results</h3>
        </div>

        <div class="widget-content">
            <div id="map_canvas" style="height: 362px;"></div>
        </div>
    </div>
</div>

You can add a class of row to the div inside the col-md-4 and the row's -15px margin will balance out the gutter from the columns. Good explanation here about gutters and rows in Bootstrap 3.

Doctrine - How to print out the real sql, not just the prepared statement?

To print out an SQL query in Doctrine, use:

$query->getResult()->getSql();

Remove duplicate elements from array in Ruby

Just to provide some insight:

require 'fruity'
require 'set'

array = [1,2,2,1,4,4,5,6,7,8,5,6] * 1_000

def mithun_sasidharan(ary)
  ary.uniq
end

def jaredsmith(ary)
  ary & ary
end

def lri(ary)
  counts = Hash.new(0)
  ary.each { |v| counts[v] += 1 }
  counts.select { |v, count| count == 1 }.keys 
end

def finks(ary)
  ary.to_set
end

def santosh_mohanty(ary)
    result = ary.reject.with_index do |ele,index|
      res = (ary[index+1] ^ ele)
      res == 0
    end
end

SHORT_ARRAY = [1,1,2,2,3,1]
mithun_sasidharan(SHORT_ARRAY) # => [1, 2, 3]
jaredsmith(SHORT_ARRAY) # => [1, 2, 3]
lri(SHORT_ARRAY) # => [3]
finks(SHORT_ARRAY) # => #<Set: {1, 2, 3}>
santosh_mohanty(SHORT_ARRAY) # => [1, 2, 3, 1]

puts 'Ruby v%s' % RUBY_VERSION

compare do
  _mithun_sasidharan { mithun_sasidharan(array) }
  _jaredsmith { jaredsmith(array) }
  _lri { lri(array) }
  _finks { finks(array) }
  _santosh_mohanty { santosh_mohanty(array) }
end

Which, when run, results in:

# >> Ruby v2.7.1
# >> Running each test 16 times. Test will take about 2 seconds.
# >> _mithun_sasidharan is faster than _jaredsmith by 2x ± 0.1
# >> _jaredsmith is faster than _santosh_mohanty by 4x ± 0.1 (results differ: [1, 2, 4, 5, 6, 7, 8] vs [1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, ...
# >> _santosh_mohanty is similar to _lri (results differ: [1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, 7, 8, 5, 6, 1, 2, 1, 4, 5, 6, ...
# >> _lri is similar to _finks (results differ: [] vs #<Set: {1, 2, 4, 5, 6, 7, 8}>)

Note: these returned bad results:

  • lri(SHORT_ARRAY) # => [3]
  • finks(SHORT_ARRAY) # => #<Set: {1, 2, 3}>
  • santosh_mohanty(SHORT_ARRAY) # => [1, 2, 3, 1]

access denied for user @ 'localhost' to database ''

Try this: Adding users to MySQL

You need grant privileges to the user if you want external acess to database(ie. web pages).

How to start/stop/restart a thread in Java?

You can start a thread like:

    Thread thread=new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        //Do you task
                    }catch (Exception ex){
                        ex.printStackTrace();}
                }
            });
thread.start();

To stop a Thread:

   thread.join();//it will kill you thread

   //if you want to know whether your thread is alive or dead you can use
System.out.println("Thread is "+thread.isAlive());

Its advisable to create a new thread rather than restarting it.

Get current controller in view

Create base class for all controllers and put here name attribute:

public abstract class MyBaseController : Controller
{
    public abstract string Name { get; }
}

In view

@{
    var controller = ViewContext.Controller as MyBaseController;
    if (controller != null)
    {
       @controller.Name
    }
}

Controller example

 public class SampleController: MyBaseController 
    { 
      public override string Name { get { return "Sample"; } 
    }

How do you change the document font in LaTeX?

This article might be helpful with changing fonts.

From the article:

The commands to change font attributes are illustrated by the following example:

  \fontencoding{T1}
  \fontfamily{garamond}
  \fontseries{m}
  \fontshape{it}
  \fontsize{12}{15}
  \selectfont

This series of commands set the current font to medium weight italic garamond 12pt type with 15pt leading in the T1 encoding scheme, and the \selectfont command causes LaTeX to look in its mapping scheme for a metric corresponding to these attributes.

Import .bak file to a database in SQL server

On Microsoft SQL Server Management Studio 2019:

enter image description here

On Restore Database window:

  1. Choose Device

  2. Choose Add and pick target file

  3. OK to confirm

  4. OK to confirm restore

enter image description here

Import Libraries in Eclipse?

No, don't do it that way.

From your Eclipse workspace, right click your project on the left pane -> Properties -> Java Build Path -> Add Jars -> add your jars here.

Tadaa!! :)

Cancel a vanilla ECMAScript 6 Promise chain

Try promise-abortable: https://www.npmjs.com/package/promise-abortable

$ npm install promise-abortable
import AbortablePromise from "promise-abortable";

const timeout = new AbortablePromise((resolve, reject, signal) => {
  setTimeout(reject, timeToLive, error);
  signal.onabort = resolve;
});

Promise.resolve(fn()).then(() => {
  timeout.abort();
});

Effect of using sys.path.insert(0, path) and sys.path(append) when loading modules

I'm quite a beginner in Python and I found the answer of Anand was very good but quite complicated to me, so I try to reformulate :

1) insert and append methods are not specific to sys.path and as in other languages they add an item into a list or array and :
* append(item) add item to the end of the list,
* insert(n, item) inserts the item at the nth position in the list (0 at the beginning, 1 after the first element, etc ...).

2) As Anand said, python search the import files in each directory of the path in the order of the path, so :
* If you have no file name collisions, the order of the path has no impact,
* If you look after a function already defined in the path and you use append to add your path, you will not get your function but the predefined one.

But I think that it is better to use append and not insert to not overload the standard behaviour of Python, and use non-ambiguous names for your files and methods.

Split a String into an array in Swift?

var fullName = "James Keagan Michael"
let first = fullName.components(separatedBy: " ").first?.isEmpty == false ? fullName.components(separatedBy: " ").first! : "John"
let last =  fullName.components(separatedBy: " ").last?.isEmpty == false && fullName.components(separatedBy: " ").last != fullName.components(separatedBy: " ").first ? fullName.components(separatedBy: " ").last! : "Doe"
  • Disallow same first and last name
  • If a fullname is invalid, take placeholder value "John Doe"

How to obtain the last index of a list?

all above answers is correct but however

a = [];
len(list1) - 1 # where 0 - 1 = -1

to be more precisely

a = [];
index = len(a) - 1 if a else None;

if index == None : raise Exception("Empty Array")

since arrays is starting with 0

jQuery - checkbox enable/disable

Here's another sample using JQuery 1.10.2

$(".chkcc9").on('click', function() {
            $(this)
            .parents('table')
            .find('.group1') 
            .prop('checked', $(this).is(':checked')); 
});

X11/Xlib.h not found in Ubuntu

Andrew White's answer is sufficient to get you moving. Here's a step-by-step for beginners.

A simple get started:

Create test.cpp: (This will be built and run to verify you got things set up right.)

#include <X11/Xlib.h>
#include <unistd.h>


main()
{
  // Open a display.
  Display *d = XOpenDisplay(0);

  if ( d )
    {
      // Create the window
      Window w = XCreateWindow(d, DefaultRootWindow(d), 0, 0, 200,
                   100, 0, CopyFromParent, CopyFromParent,
                   CopyFromParent, 0, 0);

      // Show the window
      XMapWindow(d, w);
      XFlush(d);

      // Sleep long enough to see the window.
      sleep(10);
    }
  return 0;
}

(Source: LinuxGazette)

Try: g++ test.cpp -lX11 If it builds to a.out, try running it. If you see a simple window drawn, you have the necessary libraries, and some other root problem is afoot.

If your response is:

    test.cpp:1:22: fatal error: X11/Xlib.h: No such file or directory
    compilation terminated.

you need to install X11 development libraries. sudo apt-get install libx11-dev

Retry g++ test.cpp -lX11

If it works, you're golden.

Tested using a fresh install of libX11-dev_2%3a1.5.0-1_i386.deb

How can I throw CHECKED exceptions from inside Java 8 streams?

You can't do this safely. You can cheat, but then your program is broken and this will inevitably come back to bite someone (it should be you, but often our cheating blows up on someone else.)

Here's a slightly safer way to do it (but I still don't recommend this.)

class WrappedException extends RuntimeException {
    Throwable cause;

    WrappedException(Throwable cause) { this.cause = cause; }
}

static WrappedException throwWrapped(Throwable t) {
    throw new WrappedException(t);
}

try 
    source.stream()
          .filter(e -> { ... try { ... } catch (IOException e) { throwWrapped(e); } ... })
          ...
}
catch (WrappedException w) {
    throw (IOException) w.cause;
}

Here, what you're doing is catching the exception in the lambda, throwing a signal out of the stream pipeline that indicates that the computation failed exceptionally, catching the signal, and acting on that signal to throw the underlying exception. The key is that you are always catching the synthetic exception, rather than allowing a checked exception to leak out without declaring that exception is thrown.

The name 'InitializeComponent' does not exist in the current context

I've had this (although it was very much my fault and was caused after I copied and pasted some code in); it can occur when the namespace doesn't match between the XAML and code behind

EG

<UserControl x:Class="DockPanel.TreeView" />

and the code behind is

namespace NotDockPanel

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

As shown below, range only supports integers:

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

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

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

range(int(c/10))

or by using //, which returns an integer:

range(c//10)

Is Python faster and lighter than C++?

I think you're reading those stats incorrectly. They show that Python is up to about 400 times slower than C++ and with the exception of a single case, Python is more of a memory hog. When it comes to source size though, Python wins flat out.

My experiences with Python show the same definite trend that Python is on the order of between 10 and 100 times slower than C++ when doing any serious number crunching. There are many reasons for this, the major ones being: a) Python is interpreted, while C++ is compiled; b) Python has no primitives, everything including the builtin types (int, float, etc.) are objects; c) a Python list can hold objects of different type, so each entry has to store additional data about its type. These all severely hinder both runtime and memory consumption.

This is no reason to ignore Python though. A lot of software doesn't require much time or memory even with the 100 time slowness factor. Development cost is where Python wins with the simple and concise style. This improvement on development cost often outweighs the cost of additional cpu and memory resources. When it doesn't, however, then C++ wins.

How do I get the current time zone of MySQL?

To get the current time according to your timezone, you can use the following (in my case its '+5:30')

select DATE_FORMAT(convert_tz(now(),@@session.time_zone,'+05:30') ,'%Y-%m-%d')

Using jquery to get all checked checkboxes with a certain class name

$('input.yourClass:checkbox:checked').each(function () {
    var sThisVal = $(this).val();
});

This would get all checkboxes of the class name "yourClass". I like this example since it uses the jQuery selector checked instead of doing a conditional check. Personally I would also use an array to store the value, then use them as needed, like:

var arr = [];
$('input.yourClass:checkbox:checked').each(function () {
    arr.push($(this).val());
});

jquery change div text

Put the title in its own span.

<span id="dialog_title_span">'+dialog_title+'</span>
$('#dialog_title_span').text("new dialog title");

jQuery: how to scroll to certain anchor/div on page load?

There's no need to use jQuery because this is native JavaScript functionality

element.scrollIntoView()

How can I compile and run c# program without using visual studio?

I use a batch script to compile and run C#:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\csc /out:%1 %2

@echo off

if errorlevel 1 (
    pause
    exit
)

start %1 %1

I call it like this:

C:\bin\csc.bat "C:\code\MyProgram.exe" "C:\code\MyProgram.cs"

I also have a shortcut in Notepad++, which you can define by going to Run > Run...:

C:\bin\csc.bat "$(CURRENT_DIRECTORY)\$(NAME_PART).exe" "$(FULL_CURRENT_PATH)"

I assigned this shortcut to my F5 key for maximum laziness.

How to use LINQ Distinct() with multiple fields

Use the Key keyword in your select will work, like below.

product.Select(m => new {Key m.CategoryId, Key m.CategoryName}).Distinct();

I realize this is bringing up an old thread but figured it might help some people. I generally code in VB.NET when working with .NET so Key may translate differently into C#.

Session 'app' error while installing APK

It's a bit late for reply but, i've figured out how to solve this problem on Android Studio 3.1.

You can have "Instant Run" checked, what you need to do it's just to build an APK

enter image description here

and then retry to Run your app.

Hope this help!

Can't draw Histogram, 'x' must be numeric

Because of the thousand separator, the data will have been read as 'non-numeric'. So you need to convert it:

 we <- gsub(",", "", we)   # remove comma
 we <- as.numeric(we)      # turn into numbers

and now you can do

 hist(we)

and other numeric operations.

How to write Unicode characters to the console?

It's likely that your output encoding is set to ASCII. Try using this before sending output:

Console.OutputEncoding = System.Text.Encoding.UTF8;

(MSDN link to supporting documentation.)

And here's a little console test app you may find handy:

C#

using System;
using System.Text;

public static class ConsoleOutputTest {
    public static void Main() {
        Console.OutputEncoding = System.Text.Encoding.UTF8;
        for (var i = 0; i <= 1000; i++) {
            Console.Write(Strings.ChrW(i));
            if (i % 50 == 0) { // break every 50 chars
                Console.WriteLine();
            }
        }
        Console.ReadKey();
    }
}

VB.NET

imports Microsoft.VisualBasic
imports System

public module ConsoleOutputTest 
    Sub Main()
        Console.OutputEncoding = System.Text.Encoding.UTF8
        dim i as integer
        for i = 0 to 1000
            Console.Write(ChrW(i))
            if i mod 50 = 0 'break every 50 chars 
                Console.WriteLine()
            end if
        next
    Console.ReadKey()
    End Sub
end module

It's also possible that your choice of Console font does not support that particular character. Click on the Windows Tool-bar Menu (icon like C:.) and select Properties -> Font. Try some other fonts to see if they display your character properly:

picture of console font edit

Showing all session data at once?

echo "<pre>";
print_r($this->session->all_userdata());
echo "</pre>";

Display yet formatting then you can view properly.

SQL Server Case Statement when IS NULL

Take a look at the ISNULL function. It helps you replace NULL values for other values. http://msdn.microsoft.com/en-us/library/ms184325.aspx

No tests found with test runner 'JUnit 4'

May be your JUnit launch configuration was for a individual test class, and you somehow changed that config to "run all tests in a source folder, package or project"

But that could trigger the "No tests found with test runner 'JUnit 4'" error message.

Or you did a modification in your test class, removing the @Test annotation.
See this wiki page.

Visual Studio - How to change a project's folder name and solution name without breaking the solution

I found that these instructions were not enough. I also had to search through the code files for models, controllers, and views as well as the AppStart files to change the namespace.

Since I was copying my project not just renaming it, I also had to go into the applicationhost.config for IIS express and recreate the bindings using different port numbers and change the physical directory as well.

Spring CORS No 'Access-Control-Allow-Origin' header is present

I have found the solution in spring boot by using @CrossOrigin annotation.

@RestController
@CrossOrigin
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**");
    }
}

How to fix Array indexOf() in JavaScript for Internet Explorer browsers

You should check if it's not defined using if (!Array.prototype.indexOf).

Also, your implementation of indexOf is not correct. You must use === instead of == in your if (this[i] == obj) statement, otherwise [4,"5"].indexOf(5) would be 1 according to your implementation, which is incorrect.

I recommend you use the implementation on MDC.

Find elements inside forms and iframe using Java and Selenium WebDriver

By using https://github.com/nick318/FindElementInFrames You can find webElement across all frames:

SearchByFramesFactory searchFactory = new SearchByFramesFactory(driver);
SearchByFrames searchInFrame = searchFactory.search(() -> driver.findElement(By.tagName("body")));
Optional<WebElement> elem = searchInFrame.getElem();

syntax error: unexpected token <

This happened to me with a page loaded in via an iframe. The iframe src page had a 404 script reference. Obviously I couldn't find the script reference in the parent page, so it took me a while to find the culprit.

How to detect when WIFI Connection has been established in Android?

I used this code:

public class MainActivity extends Activity
    {
    .
    .
    .
    @Override
    protected void onCreate(Bundle savedInstanceState)
        {
        super.onCreate(savedInstanceState);
        .
        .
        .
        }

    @Override
    protected void onResume()
        {
        super.onResume();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION);
        registerReceiver(broadcastReceiver, intentFilter);  
        }

    @Override
    protected void onPause()
        {
        super.onPause();
        unregisterReceiver(broadcastReceiver);
        }

    private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver()
        {
        @Override
        public void onReceive(Context context, Intent intent)
            {
            final String action = intent.getAction();
            if (action.equals(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION))
                {
                if (intent.getBooleanExtra(WifiManager.EXTRA_SUPPLICANT_CONNECTED, false))
                    {
                    // wifi is enabled
                    }
                else
                    {
                    // wifi is disabled
                    }
                }
            }
        };
    }

Import pandas dataframe column as string not int

Just want to reiterate this will work in pandas >= 0.9.1:

In [2]: read_csv('sample.csv', dtype={'ID': object})
Out[2]: 
                           ID
0  00013007854817840016671868
1  00013007854817840016749251
2  00013007854817840016754630
3  00013007854817840016781876
4  00013007854817840017028824
5  00013007854817840017963235
6  00013007854817840018860166

I'm creating an issue about detecting integer overflows also.

EDIT: See resolution here: https://github.com/pydata/pandas/issues/2247

Update as it helps others:

To have all columns as str, one can do this (from the comment):

pd.read_csv('sample.csv', dtype = str)

To have most or selective columns as str, one can do this:

# lst of column names which needs to be string
lst_str_cols = ['prefix', 'serial']
# use dictionary comprehension to make dict of dtypes
dict_dtypes = {x : 'str'  for x in lst_str_cols}
# use dict on dtypes
pd.read_csv('sample.csv', dtype=dict_dtypes)

Passing arguments to require (when loading module)

Based on your comments in this answer, I do what you're trying to do like this:

module.exports = function (app, db) {
    var module = {};

    module.auth = function (req, res) {
        // This will be available 'outside'.
        // Authy stuff that can be used outside...
    };

    // Other stuff...
    module.pickle = function(cucumber, herbs, vinegar) {
        // This will be available 'outside'.
        // Pickling stuff...
    };

    function jarThemPickles(pickle, jar) {
        // This will be NOT available 'outside'.
        // Pickling stuff...

        return pickleJar;
    };

    return module;
};

I structure pretty much all my modules like that. Seems to work well for me.

Test a weekly cron job

Just do what cron does, run the following as root:

run-parts -v /etc/cron.weekly

... or the next one if you receive the "Not a directory: -v" error:

run-parts /etc/cron.weekly -v

Option -v prints the script names before they are run.

How to return a value from pthread threads in C?

if you're uncomfortable with returning addresses and have just a single variable eg. an integer value to return, you can even typecast it into (void *) before passing it, and then when you collect it in the main, again typecast it into (int). You have the value without throwing up ugly warnings.

How to convert List<string> to List<int>?

What no TryParse? Safe LINQ version that filters out invalid ints (for C# 6.0 and below):

List<int>  ints = strings
    .Select(s => { int i; return int.TryParse(s, out i) ? i : (int?)null; })
    .Where(i => i.HasValue)
    .Select(i => i.Value)
    .ToList();

credit to Olivier Jacot-Descombes for the idea and the C# 7.0 version.

Best practices with STDIN in Ruby?

I'll add that in order to use ARGF with parameters, you need to clear ARGV before calling ARGF.each. This is because ARGF will treat anything in ARGV as a filename and read lines from there first.

Here's an example 'tee' implementation:

File.open(ARGV[0], 'w') do |file|
  ARGV.clear

  ARGF.each do |line|
    puts line
    file.write(line)
  end
end

R legend placement in a plot

You have to add the size of the legend box to the ylim range

#Plot an empty graph and legend to get the size of the legend
x <-1:10
y <-11:20
plot(x,y,type="n", xaxt="n", yaxt="n")
my.legend.size <-legend("topright",c("Series1","Series2","Series3"),plot = FALSE)

#custom ylim. Add the height of legend to upper bound of the range
my.range <- range(y)
my.range[2] <- 1.04*(my.range[2]+my.legend.size$rect$h)

#draw the plot with custom ylim
plot(x,y,ylim=my.range, type="l")
my.legend.size <-legend("topright",c("Series1","Series2","Series3"))

enter image description here

How to search in an array with preg_match?

In this post I'll provide you with three different methods of doing what you ask for. I actually recommend using the last snippet, since it's easiest to comprehend as well as being quite neat in code.

How do I see what elements in an array that matches my regular expression?

There is a function dedicated for just this purpose, preg_grep. It will take a regular expression as first parameter, and an array as the second.

See the below example:

$haystack = array (
  'say hello',
  'hello stackoverflow',
  'hello world',
  'foo bar bas'
);

$matches  = preg_grep ('/^hello (\w+)/i', $haystack);

print_r ($matches);

output

Array
(
    [1] => hello stackoverflow
    [2] => hello world
)

Documentation


But I just want to get the value of the specified groups. How?

array_reduce with preg_match can solve this issue in clean manner; see the snippet below.

$haystack = array (
  'say hello',
  'hello stackoverflow',
  'hello world',
  'foo bar bas'
);

function _matcher ($m, $str) {
  if (preg_match ('/^hello (\w+)/i', $str, $matches))
    $m[] = $matches[1];

  return $m;
}

// N O T E :
// ------------------------------------------------------------------------------
// you could specify '_matcher' as an anonymous function directly to
// array_reduce though that kind of decreases readability and is therefore
// not recommended, but it is possible.

$matches = array_reduce ($haystack, '_matcher', array ());

print_r ($matches);

output

Array
(
    [0] => stackoverflow
    [1] => world
)

Documentation


Using array_reduce seems tedious, isn't there another way?

Yes, and this one is actually cleaner though it doesn't involve using any pre-existing array_* or preg_* function.

Wrap it in a function if you are going to use this method more than once.

$matches = array ();

foreach ($haystack as $str) 
  if (preg_match ('/^hello (\w+)/i', $str, $m))
    $matches[] = $m[1];

Documentation

How can I style even and odd elements?

The :nth-child(n) selector matches every element that is the nth child, regardless of type, of its parent. Odd and even are keywords that can be used to match child elements whose index is odd or even (the index of the first child is 1).

this is what you want:

<html>
    <head>
        <style>
            li { color: blue }<br>
            li:nth-child(even) { color:red }
            li:nth-child(odd) { color:green}
        </style>
    </head>
    <body>
        <ul>
            <li>ho</li>
            <li>ho</li>
            <li>ho</li>
            <li>ho</li>
            <li>ho</li>
        </ul>
    </body>
</html>

Creating .pem file for APNS?

Steps:

  1. Create a CSR Using Key Chain Access
  2. Create a P12 Using Key Chain Access using private key
  3. APNS App ID and certificate

This gives you three files:

  • The CSR
  • The private key as a p12 file (PushChatKey.p12)
  • The SSL certificate, aps_development.cer

Go to the folder where you downloaded the files, in my case the Desktop:

$ cd ~/Desktop/

Convert the .cer file into a .pem file:

$ openssl x509 -in aps_development.cer -inform der -out PushChatCert.pem

Convert the private key’s .p12 file into a .pem file:

$ openssl pkcs12 -nocerts -out PushChatKey.pem -in PushChatKey.p12

Enter Import Password:

MAC verified OK Enter PEM pass phrase: Verifying - Enter PEM pass phrase:

You first need to enter the passphrase for the .p12 file so that openssl can read it. Then you need to enter a new passphrase that will be used to encrypt the PEM file. Again for this tutorial I used “pushchat” as the PEM passphrase. You should choose something more secure. Note: if you don’t enter a PEM passphrase, openssl will not give an error message but the generated .pem file will not have the private key in it.

Finally, combine the certificate and key into a single .pem file:

$ cat PushChatCert.pem PushChatKey.pem > ck.pem

android.widget.Switch - on/off event listener?

You can use DataBinding and ViewModel for Switch Checked Change event

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

    <data>

        <variable
                name="viewModel"
                type="com.example.ui.ViewModel" />
    </data>
    <Switch
            android:id="@+id/on_off_switch"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onCheckedChanged="@{(button, on) -> viewModel.onCheckedChange(on)}"
     />

Set a form's action attribute when submitting?

<input type='submit' value='Submit' onclick='this.form.action="somethingelse";' />

Or you can modify it from outside the form, with javascript the normal way:

 document.getElementById('form_id').action = 'somethingelse';

Include php files when they are in different folders

None of the above answers fixed this issue for me. I did it as following (Laravel with Ubuntu server):

<?php
     $footerFile = '/var/www/website/main/resources/views/emails/elements/emailfooter.blade.php';
     include($footerFile);
?>

Set EditText cursor color

For anyone that needs to set the EditText cursor color dynamically, below you will find two ways to achieve this.


First, create your cursor drawable:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <solid android:color="#ff000000" />

    <size android:width="1dp" />

</shape>

Set the cursor drawable resource id to the drawable you created (https://github.com/android/platform_frameworks_base/blob/kitkat-release/core/java/android/widget/TextView.java#L562-564">source)):

try {
    Field f = TextView.class.getDeclaredField("mCursorDrawableRes");
    f.setAccessible(true);
    f.set(yourEditText, R.drawable.cursor);
} catch (Exception ignored) {
}

To just change the color of the default cursor drawable, you can use the following method:

public static void setCursorDrawableColor(EditText editText, int color) {
    try {
        Field fCursorDrawableRes = 
            TextView.class.getDeclaredField("mCursorDrawableRes");
        fCursorDrawableRes.setAccessible(true);
        int mCursorDrawableRes = fCursorDrawableRes.getInt(editText);
        Field fEditor = TextView.class.getDeclaredField("mEditor");
        fEditor.setAccessible(true);
        Object editor = fEditor.get(editText);
        Class<?> clazz = editor.getClass();
        Field fCursorDrawable = clazz.getDeclaredField("mCursorDrawable");
        fCursorDrawable.setAccessible(true);

        Drawable[] drawables = new Drawable[2];
        Resources res = editText.getContext().getResources();
        drawables[0] = res.getDrawable(mCursorDrawableRes);
        drawables[1] = res.getDrawable(mCursorDrawableRes);
        drawables[0].setColorFilter(color, PorterDuff.Mode.SRC_IN);
        drawables[1].setColorFilter(color, PorterDuff.Mode.SRC_IN);
        fCursorDrawable.set(editor, drawables);
    } catch (final Throwable ignored) {
    }
}

Casting a variable using a Type variable

Here is my method to cast an object but not to a generic type variable, rather to a System.Type dynamically:

I create a lambda expression at run-time using System.Linq.Expressions, of type Func<object, object>, that unboxes its input, performs the desired type conversion then gives the result boxed. A new one is needed not only for all types that get casted to, but also for the types that get casted (because of the unboxing step). Creating these expressions is highly time consuming, because of the reflection, the compilation and the dynamic method building that is done under the hood. Luckily once created, the expressions can be invoked repeatedly and without high overhead, so I cache each one.

private static Func<object, object> MakeCastDelegate(Type from, Type to)
{
    var p = Expression.Parameter(typeof(object)); //do not inline
    return Expression.Lambda<Func<object, object>>(
        Expression.Convert(Expression.ConvertChecked(Expression.Convert(p, from), to), typeof(object)),
        p).Compile();
}

private static readonly Dictionary<Tuple<Type, Type>, Func<object, object>> CastCache
= new Dictionary<Tuple<Type, Type>, Func<object, object>>();

public static Func<object, object> GetCastDelegate(Type from, Type to)
{
    lock (CastCache)
    {
        var key = new Tuple<Type, Type>(from, to);
        Func<object, object> cast_delegate;
        if (!CastCache.TryGetValue(key, out cast_delegate))
        {
            cast_delegate = MakeCastDelegate(from, to);
            CastCache.Add(key, cast_delegate);
        }
        return cast_delegate;
    }
}

public static object Cast(Type t, object o)
{
    return GetCastDelegate(o.GetType(), t).Invoke(o);
}

Note that this isn't magic. Casting doesn't occur in code, as it does with the dynamic keyword, only the underlying data of the object gets converted. At compile-time we are still left to painstakingly figure out exactly what type our object might be, making this solution impractical. I wrote this as a hack to invoke conversion operators defined by arbitrary types, but maybe somebody out there can find a better use case.

Rails 3 check if attribute changed

For rails 5.1+ callbacks

As of Ruby on Rails 5.1, the attribute_changed? and attribute_was ActiveRecord methods will be deprecated

Use saved_change_to_attribute? instead of attribute_changed?

@user.saved_change_to_street1? # => true/false

More examples here

Difference between maven scope compile and provided for JAR packaging

If jar file is like executable spring boot jar file then scope of all dependencies must be compile to include all jar files.

But if jar file used in other packages or applications then it does not need to include all dependencies in jar file because these packages or applications can provide other dependencies themselves.

Where are the python modules stored?

  1. You can iterate through directories listed in sys.path to find all modules (except builtin ones).
  2. It'll probably be somewhere around /usr/lib/pythonX.X/site-packages (again, see sys.path). And consider using native Python package management (via pip or easy_install, plus yolk) instead, packages in Linux distros-maintained repositories tend to be outdated.

Undo git pull, how to bring repos to old state

it works first use: git reflog

find your SHA of your previus state and make (HEAD@{1} is an example)

git reset --hard HEAD@{1}

How to move a marker in Google Maps API

You are using the correct API, but is the "marker" variable visible to the entire script. I don't see this marker variable declared globally.

How to do perspective fixing?

The simple solution is to just remap coordinates from the original to the final image, copying pixels from one coordinate space to the other, rounding off as necessary -- which may result in some pixels being copied several times adjacent to each other, and other pixels being skipped, depending on whether you're stretching or shrinking (or both) in either dimension. Make sure your copying iterates through the destination space, so all pixels are covered there even if they're painted more than once, rather than thru the source which may skip pixels in the output.

The better solution involves calculating the corresponding source coordinate without rounding, and then using its fractional position between pixels to compute an appropriate average of the (typically) four pixels surrounding that location. This is essentially a filtering operation, so you lose some resolution -- but the result looks a LOT better to the human eye; it does a much better job of retaining small details and avoids creating straight-line artifacts which humans find objectionable.

Note that the same basic approach can be used to remap flat images onto any other shape, including 3D surface mapping.

Finding all objects that have a given property inside a collection

Solutions based on predicates, filters and custom iterators/comparators are nice, but they don't provide analogue with database index. For instance: I would like to search collection of cats different ways: by sex and age and by age, so it looks like two indexes: 1) [sex, age] 2) [age]. Values, accessed by that indexes could be hashed, to implement fast lookup, without iterating the whole collection. Is anywhere there such solution?

org.hibernate.PersistentObjectException: detached entity passed to persist

For JPA fixed using EntityManager merge() instead of persist()

EntityManager em = getEntityManager();
    try {
        em.getTransaction().begin();
        em.merge(fieldValue);
        em.getTransaction().commit();
    } catch (Exception e) {
        //do smthng
    } finally {
        em.close();
    }

How to use find command to find all files with extensions from list?

find -E /path/to -regex ".*\.(jpg|gif|png|jpeg)" > log

The -E saves you from having to escape the parens and pipes in your regex.

Spring: Why do we autowire the interface and not the implemented class?

How does spring know which polymorphic type to use.

As long as there is only a single implementation of the interface and that implementation is annotated with @Component with Spring's component scan enabled, Spring framework can find out the (interface, implementation) pair. If component scan is not enabled, then you have to define the bean explicitly in your application-config.xml (or equivalent spring configuration file).

Do I need @Qualifier or @Resource?

Once you have more than one implementation, then you need to qualify each of them and during auto-wiring, you would need to use the @Qualifier annotation to inject the right implementation, along with @Autowired annotation. If you are using @Resource (J2EE semantics), then you should specify the bean name using the name attribute of this annotation.

Why do we autowire the interface and not the implemented class?

Firstly, it is always a good practice to code to interfaces in general. Secondly, in case of spring, you can inject any implementation at runtime. A typical use case is to inject mock implementation during testing stage.

interface IA
{
  public void someFunction();
}


class B implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someBfunc()
  {
     //doing b things
  }
}


class C implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someCfunc()
  {
     //doing C things
  }
}

class MyRunner
{
     @Autowire
     @Qualifier("b") 
     IA worker;

     ....
     worker.someFunction();
}

Your bean configuration should look like this:

<bean id="b" class="B" />
<bean id="c" class="C" />
<bean id="runner" class="MyRunner" />

Alternatively, if you enabled component scan on the package where these are present, then you should qualify each class with @Component as follows:

interface IA
{
  public void someFunction();
}

@Component(value="b")
class B implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someBfunc()
  {
     //doing b things
  }
}


@Component(value="c")
class C implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someCfunc()
  {
     //doing C things
  }
}

@Component    
class MyRunner
{
     @Autowire
     @Qualifier("b") 
     IA worker;

     ....
     worker.someFunction();
}

Then worker in MyRunner will be injected with an instance of type B.

Function stoi not declared

The answers above are correct, but not well explained.

g++ -std=c++11 my_cpp_code.cpp

Add -std=c++11 to your compiler options since you are most likely using an older version of debian or ubuntu which is not using by default the new c++11 standard of g++/gcc. I had the same problem on Debian Wheezy.

http://en.cppreference.com/w/cpp/string/basic_string/stol

shows in really small writing to the right in green that c++11 is required.

How can I get file extensions with JavaScript?

For most applications, a simple script such as

return /[^.]+$/.exec(filename);

would work just fine (as provided by Tom). However this is not fool proof. It does not work if the following file name is provided:

image.jpg?foo=bar

It may be a bit overkill but I would suggest using a url parser such as this one to avoid failure due to unpredictable filenames.

Using that particular function, you could get the file name like this:

var trueFileName = parse_url('image.jpg?foo=bar').file;

This will output "image.jpg" without the url vars. Then you are free to grab the file extension.

"Least Astonishment" and the Mutable Default Argument

The shortest answer would probably be "definition is execution", therefore the whole argument makes no strict sense. As a more contrived example, you may cite this:

def a(): return []

def b(x=a()):
    print x

Hopefully it's enough to show that not executing the default argument expressions at the execution time of the def statement isn't easy or doesn't make sense, or both.

I agree it's a gotcha when you try to use default constructors, though.

C# SQL Server - Passing a list to a stored procedure

CREATE TYPE [dbo].[StringList1] AS TABLE(
[Item] [NVARCHAR](MAX) NULL,
[counts][nvarchar](20) NULL);

create a TYPE as table and name it as"StringList1"

create PROCEDURE [dbo].[sp_UseStringList1]
@list StringList1 READONLY
AS
BEGIN
    -- Just return the items we passed in
    SELECT l.item,l.counts FROM @list l;
    SELECT l.item,l.counts into tempTable FROM @list l;
 End

The create a procedure as above and name it as "UserStringList1" s

String strConnection = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString.ToString();
            SqlConnection con = new SqlConnection(strConnection);
            con.Open();
            var table = new DataTable();

            table.Columns.Add("Item", typeof(string));
            table.Columns.Add("count", typeof(string));

            for (int i = 0; i < 10; i++)
            {
                table.Rows.Add(i.ToString(), (i+i).ToString());

            }
                SqlCommand cmd = new SqlCommand("exec sp_UseStringList1 @list", con);


                    var pList = new SqlParameter("@list", SqlDbType.Structured);
                    pList.TypeName = "dbo.StringList1";
                    pList.Value = table;

                    cmd.Parameters.Add(pList);
                    string result = string.Empty;
                    string counts = string.Empty;
                    var dr = cmd.ExecuteReader();

                    while (dr.Read())
                    {
                        result += dr["Item"].ToString();
                        counts += dr["counts"].ToString();
                    }

in the c#,Try this

Convert to Datetime MM/dd/yyyy HH:mm:ss in Sql Server

Declare @month as char(2)
Declare @date as char(2)
Declare @year as char(4)
declare @time as char(8)
declare @customdate as varchar(20)

set @month = MONTH(GetDate());
set @date = Day(GetDate());
set @year = year(GetDate());

set @customdate= @month+'/'+@date+'/'+@year+' '+ CONVERT(varchar(8), GETDATE(),108);
print(@customdate)

How to compare a local git branch with its remote branch?

If you want to see the difference as just the names of the files changed then use:

git diff --name-status <remote-branch> <local-branch>,

else this would show all differences between the two branches:

git diff <remote-branch> <local-branch>

How to convert interface{} to string?

You don't need to use a type assertion, instead just use the %v format specifier with Sprintf:

hostAndPort := fmt.Sprintf("%v:%v", arguments["<host>"], arguments["<port>"])

How to send a POST request from node.js Express?

I use superagent, which is simliar to jQuery.

Here is the docs

And the demo like:

var sa = require('superagent');
sa.post('url')
  .send({key: value})
  .end(function(err, res) {
    //TODO
  });

Spring REST Service: how to configure to remove null objects in json response

If you are using Jackson 2, the message-converters tag is:

<mvc:annotation-driven>
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <property name="prefixJson" value="true"/>
            <property name="supportedMediaTypes" value="application/json"/>
            <property name="objectMapper">
                <bean class="com.fasterxml.jackson.databind.ObjectMapper">
                    <property name="serializationInclusion" value="NON_NULL"/>
                </bean>
            </property>
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>

Cut Java String at a number of character

You can use String#substring()

if(str != null && str.length() > 8) {
    return str.substring(0, 8) + "...";
} else {
    return str;
}

You could however make a function where you pass the maximum number of characters that can be displayed. The ellipsis would then cut in only if the width specified isn't enough for the string.

public String getShortString(String input, int width) {
  if(str != null && str.length() > width) {
      return str.substring(0, width - 3) + "...";
  } else {
      return str;
  }
}

// abcdefgh...
System.out.println(getShortString("abcdefghijklmnopqrstuvwxyz", 11));

// abcdefghijk
System.out.println(getShortString("abcdefghijk", 11)); // no need to trim

How to enable scrolling of content inside a modal?

I'm having this issue on Mobile Safari on my iPhone6

Bootstrap adds the class .modal-open to the body when a modal is opened.

I've tried to make minimal overrides to Bootstrap 3.2.0, and came up with the following:

.modal-open {
    position: fixed;
}

.modal {
    overflow-y: auto;
}

For comparison, I've included the associated Bootstrap styles below.

Selected extract from bootstrap/less/modals.less (don't include this in your fix):

// Kill the scroll on the body
.modal-open {
  overflow: hidden;
}

// Container that the modal scrolls within
.modal {
  display: none;
  overflow: hidden;
  position: fixed;
  -webkit-overflow-scrolling: touch;
}

.modal-open .modal {
  overflow-x: hidden;
  overflow-y: auto;
}

Mobile Safari version used: User-Agent Mozilla/5.0 (iPhone; CPU iPhone OS 8_1 like Mac OS X) AppleWebKit/600.1.4 (KHTML, like Gecko) Version/8.0 Mobile/12B411 Safari/600.1.4

git: undo all working dir changes including new files

Safest method, which I use frequently:

git clean -fd

Syntax explanation as per /docs/git-clean page:

  • -f (alias: --force). If the Git configuration variable clean.requireForce is not set to false, git clean will refuse to delete files or directories unless given -f, -n or -i. Git will refuse to delete directories with .git sub directory or file unless a second -f is given.
  • -d. Remove untracked directories in addition to untracked files. If an untracked directory is managed by a different Git repository, it is not removed by default. Use -f option twice if you really want to remove such a directory.

As mentioned in the comments, it might be preferable to do a git clean -nd which does a dry run and tells you what would be deleted before actually deleting it.

Link to git clean doc page: https://git-scm.com/docs/git-clean

MySQL show current connection info

If you want to know the port number of your local host on which Mysql is running you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'port';


mysql> SHOW VARIABLES WHERE Variable_name = 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.00 sec)

It will give you the port number on which MySQL is running.


If you want to know the hostname of your Mysql you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'hostname';


mysql> SHOW VARIABLES WHERE Variable_name = 'hostname';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| hostname          | Dell  |
+-------------------+-------+
1 row in set (0.00 sec)

It will give you the hostname for mysql.


If you want to know the username of your Mysql you can use this query on MySQL Command line client --

select user();   


mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

It will give you the username for mysql.

Java 6 Unsupported major.minor version 51.0

I ran into the same problem. I use jdk 1.8 and maven 3.3.9 Once I export JAVA_HOME, I did not see this error. export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/

Normalize numpy array columns in python

You can use sklearn.preprocessing:

from sklearn.preprocessing import normalize
data = np.array([
    [1000, 10, 0.5],
    [765, 5, 0.35],
    [800, 7, 0.09], ])
data = normalize(data, axis=0, norm='max')
print(data)
>>[[ 1.     1.     1.   ]
[ 0.765  0.5    0.7  ]
[ 0.8    0.7    0.18 ]]

How to compare arrays in JavaScript?

If the array is plain and the order is matter so this two lines may help

//Assume
var a = ['a','b', 'c']; var b = ['a','e', 'c'];  

if(a.length !== b.length) return false;
return !a.reduce(
  function(prev,next,idx, arr){ return prev || next != b[idx] },false
); 

Reduce walks through one of array and returns 'false' if at least one element of 'a' is nor equial to element of 'b' Just wrap this into function

What are database constraints?

Constraints are nothing but the rules on the data. What data is valid and what is invalid can be defined using constraints. So, that integrity of data can be maintained. Following are the widely used constraints:

  1. Primary Key : which uniquely identifies the data . If this constraint has been specified for certain column then we can't enter duplicate data in that column
  2. Check : Such as NOT NULL . Here we can specify what data we can enter for that particular column and what is not expected for that column.
  3. Foreign key : Foreign key references to the row of other table. So that data referred in one table from another table is always available for the referencing table.

A html space is showing as %2520 instead of %20

For some - possibly valid - reason the url was encoded twice. %25 is the urlencoded % sign. So the original url looked like:

http://server.com/my path/

Then it got urlencoded once:

http://server.com/my%20path/

and twice:

http://server.com/my%2520path/

So you should do no urlencoding - in your case - as other components seems to to that already for you. Use simply a space

Extracting time from POSIXct

There have been previous answers that showed the trick. In essence:

  • you must retain POSIXct types to take advantage of all the existing plotting functions

  • if you want to 'overlay' several days worth on a single plot, highlighting the intra-daily variation, the best trick is too ...

  • impose the same day (and month and even year if need be, which is not the case here)

which you can do by overriding the day-of-month and month components when in POSIXlt representation, or just by offsetting the 'delta' relative to 0:00:00 between the different days.

So with times and val as helpfully provided by you:

## impose month and day based on first obs
ntimes <- as.POSIXlt(times)    # convert to 'POSIX list type'
ntimes$mday <- ntimes[1]$mday  # and $mon if it differs too
ntimes <- as.POSIXct(ntimes)   # convert back

par(mfrow=c(2,1))
plot(times,val)   # old times
plot(ntimes,val)  # new times

yields this contrasting the original and modified time scales:

enter image description here

How to detect if user select cancel InputBox VBA Excel

If the user clicks Cancel, a zero-length string is returned. You can't differentiate this from entering an empty string. You can however make your own custom InputBox class...

EDIT to properly differentiate between empty string and cancel, according to this answer.

Your example

Private Sub test()
    Dim result As String
    result = InputBox("Enter Date MM/DD/YYY", "Date Confirmation", Now)
    If StrPtr(result) = 0 Then
        MsgBox ("User canceled!")
    ElseIf result = vbNullString Then
        MsgBox ("User didn't enter anything!")
    Else
        MsgBox ("User entered " & result)
    End If
End Sub

Would tell the user they canceled when they delete the default string, or they click cancel.

See http://msdn.microsoft.com/en-us/library/6z0ak68w(v=vs.90).aspx

to call onChange event after pressing Enter key

Here is a common use case using class-based components: The parent component provides a callback function, the child component renders the input box, and when the user presses Enter, we pass the user's input to the parent.

class ParentComponent extends React.Component {
  processInput(value) {
    alert('Parent got the input: '+value);
  }

  render() {
    return (
      <div>
        <ChildComponent handleInput={(value) => this.processInput(value)} />
      </div>
    )
  }
}

class ChildComponent extends React.Component {
  constructor(props) {
    super(props);
    this.handleKeyDown = this.handleKeyDown.bind(this);
  }

  handleKeyDown(e) {
    if (e.key === 'Enter') {
      this.props.handleInput(e.target.value);
    }
  }

  render() {
    return (
      <div>
        <input onKeyDown={this.handleKeyDown} />
      </div>
    )
  }      
}

How to get database structure in MySQL via query

SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA='bodb' AND TABLE_NAME='abc';

works for getting all column names

Converting Stream to String and back...what are we missing?

When you testing try with UTF8 Encode stream like below

var stream = new MemoryStream();
var streamWriter = new StreamWriter(stream, System.Text.Encoding.UTF8);
Serializer.Serialize<SuperExample>(streamWriter, test);

Customize Bootstrap checkboxes

_x000D_
_x000D_
/* The customcheck */_x000D_
.customcheck {_x000D_
    display: block;_x000D_
    position: relative;_x000D_
    padding-left: 35px;_x000D_
    margin-bottom: 12px;_x000D_
    cursor: pointer;_x000D_
    font-size: 22px;_x000D_
    -webkit-user-select: none;_x000D_
    -moz-user-select: none;_x000D_
    -ms-user-select: none;_x000D_
    user-select: none;_x000D_
}_x000D_
_x000D_
/* Hide the browser's default checkbox */_x000D_
.customcheck input {_x000D_
    position: absolute;_x000D_
    opacity: 0;_x000D_
    cursor: pointer;_x000D_
}_x000D_
_x000D_
/* Create a custom checkbox */_x000D_
.checkmark {_x000D_
    position: absolute;_x000D_
    top: 0;_x000D_
    left: 0;_x000D_
    height: 25px;_x000D_
    width: 25px;_x000D_
    background-color: #eee;_x000D_
    border-radius: 5px;_x000D_
}_x000D_
_x000D_
/* On mouse-over, add a grey background color */_x000D_
.customcheck:hover input ~ .checkmark {_x000D_
    background-color: #ccc;_x000D_
}_x000D_
_x000D_
/* When the checkbox is checked, add a blue background */_x000D_
.customcheck input:checked ~ .checkmark {_x000D_
    background-color: #02cf32;_x000D_
    border-radius: 5px;_x000D_
}_x000D_
_x000D_
/* Create the checkmark/indicator (hidden when not checked) */_x000D_
.checkmark:after {_x000D_
    content: "";_x000D_
    position: absolute;_x000D_
    display: none;_x000D_
}_x000D_
_x000D_
/* Show the checkmark when checked */_x000D_
.customcheck input:checked ~ .checkmark:after {_x000D_
    display: block;_x000D_
}_x000D_
_x000D_
/* Style the checkmark/indicator */_x000D_
.customcheck .checkmark:after {_x000D_
    left: 9px;_x000D_
    top: 5px;_x000D_
    width: 5px;_x000D_
    height: 10px;_x000D_
    border: solid white;_x000D_
    border-width: 0 3px 3px 0;_x000D_
    -webkit-transform: rotate(45deg);_x000D_
    -ms-transform: rotate(45deg);_x000D_
    transform: rotate(45deg);_x000D_
}
_x000D_
<div class="container">_x000D_
 <h1>Custom Checkboxes</h1></br>_x000D_
 _x000D_
        <label class="customcheck">One_x000D_
          <input type="checkbox" checked="checked">_x000D_
          <span class="checkmark"></span>_x000D_
        </label>_x000D_
        <label class="customcheck">Two_x000D_
          <input type="checkbox">_x000D_
          <span class="checkmark"></span>_x000D_
        </label>_x000D_
        <label class="customcheck">Three_x000D_
          <input type="checkbox">_x000D_
          <span class="checkmark"></span>_x000D_
        </label>_x000D_
        <label class="customcheck">Four_x000D_
          <input type="checkbox">_x000D_
          <span class="checkmark"></span>_x000D_
        </label>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Oracle SQL query for Date format

to_date() returns a date at 00:00:00, so you need to "remove" the minutes from the date you are comparing to:

select * 
from table
where trunc(es_date) = TO_DATE('27-APR-12','dd-MON-yy')

You probably want to create an index on trunc(es_date) if that is something you are doing on a regular basis.

The literal '27-APR-12' can fail very easily if the default date format is changed to anything different. So make sure you you always use to_date() with a proper format mask (or an ANSI literal: date '2012-04-27')

Although you did right in using to_date() and not relying on implict data type conversion, your usage of to_date() still has a subtle pitfall because of the format 'dd-MON-yy'.

With a different language setting this might easily fail e.g. TO_DATE('27-MAY-12','dd-MON-yy') when NLS_LANG is set to german. Avoid anything in the format that might be different in a different language. Using a four digit year and only numbers e.g. 'dd-mm-yyyy' or 'yyyy-mm-dd'

How to run ssh-add on windows?

Original answer using git's start-ssh-agent

Make sure you have Git installed and have git's cmd folder in your PATH. For example, on my computer the path to git's cmd folder is C:\Program Files\Git\cmd

Make sure your id_rsa file is in the folder c:\users\yourusername\.ssh

Restart your command prompt if you haven't already, and then run start-ssh-agent. It will find your id_rsa and prompt you for the passphrase

Update 2019 - A better solution if you're using Windows 10: OpenSSH is available as part of Windows 10 which makes using SSH from cmd/powershell much easier in my opinion. It also doesn't rely on having git installed, unlike my previous solution.

  1. Open Manage optional features from the start menu and make sure you have Open SSH Client in the list. If not, you should be able to add it.

  2. Open Services from the start Menu

  3. Scroll down to OpenSSH Authentication Agent > right click > properties

  4. Change the Startup type from Disabled to any of the other 3 options. I have mine set to Automatic (Delayed Start)

  5. Open cmd and type where ssh to confirm that the top listed path is in System32. Mine is installed at C:\Windows\System32\OpenSSH\ssh.exe. If it's not in the list you may need to close and reopen cmd.

Once you've followed these steps, ssh-agent, ssh-add and all other ssh commands should now work from cmd. To start the agent you can simply type ssh-agent.

  1. Optional step/troubleshooting: If you use git, you should set the GIT_SSH environment variable to the output of where ssh which you ran before (e.g C:\Windows\System32\OpenSSH\ssh.exe). This is to stop inconsistencies between the version of ssh you're using (and your keys are added/generated with) and the version that git uses internally. This should prevent issues that are similar to this

Some nice things about this solution:

  • You won't need to start the ssh-agent every time you restart your computer
  • Identities that you've added (using ssh-add) will get automatically added after restarts. (It works for me, but you might possibly need a config file in your c:\Users\User\.ssh folder)
  • You don't need git!
  • You can register any rsa private key to the agent. The other solution will only pick up a key named id_rsa

Hope this helps

Adding 1 hour to time variable

Worked for me..

$timestamp = strtotime('10:09') + 60*60;

$time = date('H:i', $timestamp);

echo $time;//11:09

Explanation:

strtotime('10:09') creates a numerical timestamp in seconds, something like 1510450372. Simply add or remove the amount of seconds you need and use date() to convert it back into a human readable format.

$timestamp = strtotime('10:09') + 60*60; // 10:09 + 1 hour
$timestamp = strtotime('10:09') + 60*60*2; // 10:09 + 2 hours
$timestamp = strtotime('10:09') - 60*60; // 10:09 - 1 hour

time() also creates a numerical timestamp but for right now. You can use it in the same way.

$timestamp = time() + 60*60; // now + 1 hour

Where is svcutil.exe in Windows 7?

If you are using vs 2010 then you can get it in

C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools

I can't find my git.exe file in my Github folder

1) Install Git for Windows from here: http://git-scm.com/download/win

2) Note: During installation, Make sure "Use Git and optional Unix tools from the windows command prompt" is selected enter image description here

3) restart the Android Studio and try again

4) Go to File-> New -> Project from version control -> Git

How to read specific lines from a file (by line number)?

To print desired line. To print line above/below required line.

def dline(file,no,add_sub=0):
    tf=open(file)
    for sno,line in enumerate(tf):
        if sno==no-1+add_sub:
         print(line)
    tf.close()

execute---->dline("D:\dummy.txt",6) i.e dline("file path", line_number, if you want upper line of the searched line give 1 for lower -1 this is optional default value will be taken 0)

Why is printing "B" dramatically slower than printing "#"?

Pure speculation is that you're using a terminal that attempts to do word-wrapping rather than character-wrapping, and treats B as a word character but # as a non-word character. So when it reaches the end of a line and searches for a place to break the line, it sees a # almost immediately and happily breaks there; whereas with the B, it has to keep searching for longer, and may have more text to wrap (which may be expensive on some terminals, e.g., outputting backspaces, then outputting spaces to overwrite the letters being wrapped).

But that's pure speculation.

Extracting a parameter from a URL in WordPress

In the call back function, use the $request parameter

$parameters = $request->get_params();
echo $parameters['ppc'];

Node JS Error: ENOENT

You can include a different jade file into your template, that to from a different directory

views/
     layout.jade
static/
     page.jade

To include the layout file from views dir to static/page.jade

page.jade

extends ../views/layout

What does the error "arguments imply differing number of rows: x, y" mean?

Your data.frame mat is rectangular (n_rows!= n_cols).

Therefore, you cannot make a data.frame out of the column- and rownames, because each column in a data.frame must be the same length.

Maybe this suffices your needs:

require(reshape2)
mat$id <- rownames(mat) 
melt(mat)

How can I use jQuery in Greasemonkey?

Rob's solution is the right one--use @require with the jQuery library and be sure to reinstall your script so the directive gets processed.

One thing I think is worth adding is that you can use jQuery normally once you have included it in your script, except for AJAX methods. By default jQuery looks for XMLHttpRequest, which doesn't exist in the Greasemonkey context. I wrote about a workaround where you create a wrapper for GM_xmlhttpRequest (the Greasemonkey version of XHR) and use jQuery's ajaxSetup() to specify your wrapped version as the default. Once you do this, you can use $.get and $.post as usual.

You may also have problems with jQuery's $.getJSON because it loads JSONP using <script> tags. This leads to errors because jQuery defines the callback function in the scope of the Greasemonkey window, and the loaded scripts looks for the callback in the scope of the main window. Your best bet is to use $.get instead and parse the result with JSON.parse().

Using CSS td width absolute, position

Try to use

table {
  table-layout: auto;
}

If you use Bootstrap, class table has table-layout: fixed; by default.

Copying from one text file to another using Python

The oneliner:

open("out1.txt", "w").writelines([l for l in open("in.txt").readlines() if "tests/file/myword" in l])

Recommended with with:

with open("in.txt") as f:
    lines = f.readlines()
    lines = [l for l in lines if "ROW" in l]
    with open("out.txt", "w") as f1:
        f1.writelines(lines)

Using less memory:

with open("in.txt") as f:
    with open("out.txt", "w") as f1:
        for line in f:
            if "ROW" in line:
                f1.write(line) 

How to run stored procedures in Entity Framework Core?

Using MySQL connector and Entity Framework Core 2.0

My issue was that I was getting an exception like fx. Ex.Message = "The required column 'body' was not present in the results of a 'FromSql' operation.". So, in order to fetch rows via a stored procedure in this manner, you must return all columns for that entity type which the DBSet is associated with, even if you don't need to access all of it for your current request.

var result = _context.DBSetName.FromSql($"call storedProcedureName()").ToList(); 

OR with parameters

var result = _context.DBSetName.FromSql($"call storedProcedureName({optionalParam1})").ToList(); 

jQuery ui datepicker with Angularjs

I think you are missing the Angular ui bootstrap dependency in your module declaration, like this:

angular.module('elnApp', ['ui.bootstrap'])

See the doc for Angular-ui-bootstrap.

Best tool for inspecting PDF files?

PDFXplorer from O2 Solutions does an outstanding job of displaying the internals.

http://www.o2sol.com/pdfxplorer/overview.htm

(Free, distracting banner at the bottom).

What is the difference between URL parameters and query strings?

Parameters are key-value pairs that can appear inside URL path, and start with a semicolon character (;).

Query string appears after the path (if any) and starts with a question mark character (?).

Both parameters and query string contain key-value pairs.

In a GET request, parameters appear in the URL itself:

<scheme>://<username>:<password>@<host>:<port>/<path>;<parameters>?<query>#<fragment>

In a POST request, parameters can appear in the URL itself, but also in the datastream (as known as content).

Query string is always a part of the URL.

Parameters can be buried in form-data datastream when using POST method so they may not appear in the URL. Yes a POST request can define parameters as form data and in the URL, and this is not inconsistent because parameters can have several values.

I've found no explaination for this behavior so far. I guess it might be useful sometimes to "unhide" parameters from a POST request, or even let the code handling a GET request share some parts with the code handling a POST. Of course this can work only with server code supporting parameters in a URL.

Until you get better insights, I suggest you to use parameters only in form-data datastream of POST requests.

Sources:

What Every Developer Should Know About URLs

RFC 3986

How to log a method's execution time exactly in milliseconds?

I use very minimal, one page class implementation inspired by code from this blog post:

#import <mach/mach_time.h>

@interface DBGStopwatch : NSObject

+ (void)start:(NSString *)name;
+ (void)stop:(NSString *)name;

@end

@implementation DBGStopwatch

+ (NSMutableDictionary *)watches {
    static NSMutableDictionary *Watches = nil;
    static dispatch_once_t OnceToken;
    dispatch_once(&OnceToken, ^{
        Watches = @{}.mutableCopy;
    });
    return Watches;
}

+ (double)secondsFromMachTime:(uint64_t)time {
    mach_timebase_info_data_t timebase;
    mach_timebase_info(&timebase);
    return (double)time * (double)timebase.numer /
        (double)timebase.denom / 1e9;
}

+ (void)start:(NSString *)name {
    uint64_t begin = mach_absolute_time();
    self.watches[name] = @(begin);
}

+ (void)stop:(NSString *)name {
    uint64_t end = mach_absolute_time();
    uint64_t begin = [self.watches[name] unsignedLongLongValue];
    DDLogInfo(@"Time taken for %@ %g s",
              name, [self secondsFromMachTime:(end - begin)]);
    [self.watches removeObjectForKey:name];
}

@end

The usage of it is very simple:

  • just call [DBGStopwatch start:@"slow-operation"]; at the beginning
  • and then [DBGStopwatch stop:@"slow-operation"]; after the finish, to get the time

error: This is probably not a problem with npm. There is likely additional logging output above

Novice mistake. Make sure your package.json file is coded correctly. I had:

"start": "index node.js"
instead of:
"start": "node index.js"

17

Delete your package-lock.json file and node_modules folder. Then do npm cache clean

npm cache clean --force do npm install

What causes a java.lang.StackOverflowError

One of the (optional) arguments to the JVM is the stack size. It's -Xss. I don't know what the default value is, but if the total amount of stuff on the stack exceeds that value, you'll get that error.

Generally, infinite recursion is the cause of this, but if you were seeing that, your stack trace would have more than 5 frames.

Try adding a -Xss argument (or increasing the value of one) to see if this goes away.

How to use Bash to create a folder if it doesn't already exist?

Simply do:

mkdir /path/to/your/potentially/existing/folder

mkdir will throw an error if the folder already exists. To ignore the errors write:

mkdir -p /path/to/your/potentially/existing/folder

No need to do any checking or anything like that.


For reference:

-p, --parents no error if existing, make parent directories as needed http://man7.org/linux/man-pages/man1/mkdir.1.html

How to properly create composite primary keys - MYSQL

the syntax is CONSTRAINT constraint_name PRIMARY KEY(col1,col2,col3) for example ::

CONSTRAINT pk_PersonID PRIMARY KEY (P_Id,LastName)

the above example will work if you are writting it while you are creating the table for example ::

CREATE TABLE person (
   P_Id int ,
   ............,
   ............,
   CONSTRAINT pk_PersonID PRIMARY KEY (P_Id,LastName)
);

to add this constraint to an existing table you need to follow the following syntax

ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (P_Id,LastName)

Signed versus Unsigned Integers

Generally speaking that is correct. Without knowing anything more about why you are looking for the differences I can't think of any other differentiators between signed and unsigned.

Tkinter example code for multiple windows, why won't buttons load correctly?

I rewrote your code in a more organized, better-practiced way:

import tkinter as tk

class Demo1:
    def __init__(self, master):
        self.master = master
        self.frame = tk.Frame(self.master)
        self.button1 = tk.Button(self.frame, text = 'New Window', width = 25, command = self.new_window)
        self.button1.pack()
        self.frame.pack()

    def new_window(self):
        self.newWindow = tk.Toplevel(self.master)
        self.app = Demo2(self.newWindow)

class Demo2:
    def __init__(self, master):
        self.master = master
        self.frame = tk.Frame(self.master)
        self.quitButton = tk.Button(self.frame, text = 'Quit', width = 25, command = self.close_windows)
        self.quitButton.pack()
        self.frame.pack()

    def close_windows(self):
        self.master.destroy()

def main(): 
    root = tk.Tk()
    app = Demo1(root)
    root.mainloop()

if __name__ == '__main__':
    main()

Result:

Demo1 window Demo2 window

Uploading multiple files using formData()

This worked fine !

var fd = new FormData();

$('input[type="file"]').on('change', function (e) {
    [].forEach.call(this.files, function (file) {
        fd.append('filename[]', file);
    });
});

$.ajax({
    url: '/url/to/post/on',
    method: 'post',
    data: fd,
    contentType: false,
    processData: false,
    success: function (response) {
        console.log(response)
    },
    error: function (err) {
        console.log(err);
    }
});

HTML checkbox onclick called in Javascript

How about putting the checkbox into the label, making the label automatically "click sensitive" for the check box, and giving the checkbox a onchange event?

<label ..... ><input type="checkbox" onchange="toggleCheckbox(this)" .....> 

function toggleCheckbox(element)
 {
   element.checked = !element.checked;
 }

This will additionally catch users using a keyboard to toggle the check box, something onclick would not.

How to get all selected values from <select multiple=multiple>?

Actually, I found the best, most-succinct, fastest, and most-compatible way using pure JavaScript (assuming you don't need to fully support IE lte 8) is the following:

var values = Array.prototype.slice.call(document.querySelectorAll('#select-meal-type option:checked'),0).map(function(v,i,a) { 
    return v.value; 
});

UPDATE (2017-02-14):

An even more succinct way using ES6/ES2015 (for the browsers that support it):

const selected = document.querySelectorAll('#select-meal-type option:checked');
const values = Array.from(selected).map(el => el.value);

RHEL 6 - how to install 'GLIBC_2.14' or 'GLIBC_2.15'?

For another instance of Glibc, download gcc 4.7.2, for instance from this github repo (although an official source would be better) and extract it to some folder, then update LD_LIBRARY_PATH with the path where you have extracted glib.

export LD_LIBRARY_PATH=$glibpath/glib-2.49.4-kgesagxmtbemim2denf65on4iixy3miy/lib:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=$glibpath/libffi-3.2.1-wk2luzhfdpbievnqqtu24pi774esyqye/lib64:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=$glibpath/pcre-8.39-itdbuzevbtzqeqrvna47wstwczud67wx/lib:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=$glibpath/gettext-0.19.8.1-aoweyaoufujdlobl7dphb2gdrhuhikil/lib:$LD_LIBRARY_PATH

This should keep you safe from bricking your CentOS*.

*Disclaimer: I just completed the thought it looks like the OP was trying to express, but I don't fully agree.

Set the text in a span

You need to fix your selector. Although CSS syntax requires multiple classes to be space separated, selector syntax would require them to be directly concatenated, and dot prefixed:

$(".ui-icon.ui-icon-circle-triangle-w").text(...);

or better:

$(".ui-datepicker-prev > span").text(...);

PHP Echo a large block of text

Man, PHP is not perl!
PHP can just escape from HTML :) http://www.php.net/manual/en/language.basic-syntax.phpmode.php

if (is_single()) {
//now we just close PHP tag
?>
</style> 
<script> 
<blah blah blah>
<?php
//open it back. here is your PHP again. easy!
}
?>

I wonder why such many people stuck to ugly heredoc.

How to convert a byte to its binary string representation

You can work with BigInteger like below example, most especially if you have 256 bit or longer:

String string = "10000010";
BigInteger biStr = new BigInteger(string, 2);

System.out.println("binary: " + biStr.toString(2));
System.out.println("hex: " + biStr.toString(16));
System.out.println("dec: " + biStr.toString(10));

Another example which accepts bytes:

String string = "The girl on the red dress.";

byte[] byteString = string.getBytes(Charset.forName("UTF-8"));
System.out.println("[Input String]: " + string);
System.out.println("[Encoded String UTF-8]: " + byteString);

BigInteger biStr = new BigInteger(byteString);
System.out.println("binary: " + biStr.toString(2)); // binary
System.out.println("hex: " + biStr.toString(16));   // hex or base 16
System.out.println("dec: " + biStr.toString(10));  // this is base 10

Result:

[Input String]: The girl on the red dress.
[Encoded String UTF-8]: [B@70dea4e

binary: 101010001101000011001010010000001100111011010010111001001101100001000000110111101101110001000000111010001101000011001010010000001110010011001010110010000100000011001000111001001100101011100110111001100101110
hex: 546865206769726c206f6e20746865207265642064726573732e

You can also work to convert Binary to Byte format

try {
   System.out.println("binary to byte: " + biStr.toString(2).getBytes("UTF-8"));
} catch (UnsupportedEncodingException e) {e.printStackTrace();}

Note: For string formatting for your Binary format you can use below sample

String.format("%256s", biStr.toString(2).replace(' ', '0'));  // this is for the 256 bit formatting

How to pass optional arguments to a method in C++?

To follow the example given here, but to clarify syntax with the use of header files, the function forward declaration contains the optional parameter default value.

myfile.h

void myfunc(int blah, int mode = 0);

myfile.cpp

void myfunc(int blah, int mode) /* mode = 0 */
{
    if (mode == 0)
        do_something();
     else
        do_something_else();
}

Best way to overlay an ESRI shapefile on google maps?

Free "Export to KML" script for ArcGIS 9

Here is a list of available methods that someone found.

Also, it seems to me that the most efficient representation of a polygon layer is by using Google Maps API's polyline encoding, which significantly compresses lat-lng data. But getting into that format takes work: use ArcMap to export Shape as lat/lng coordinates, then convert into polylines using Google Maps API.

How to return a string from a C++ function?

string str1, str2, str3;

cout << "These are the strings: " << endl;
cout << "str1: \"the dog jumped over the fence\"" << endl;
cout << "str2: \"the\"" << endl;
cout << "str3: \"that\"" << endl << endl;

From this, I see that you have not initialized str1, str2, or str3 to contain the values that you are printing. I might suggest doing so first:

string str1 = "the dog jumped over the fence", 
       str2 = "the",
       str3 = "that";

cout << "These are the strings: " << endl;
cout << "str1: \"" << str1 << "\"" << endl;
cout << "str2: \"" << str2 << "\"" << endl;
cout << "str3: \"" << str3 << "\"" << endl << endl;

What is the difference between visibility:hidden and display:none?

The difference goes beyond style and is reflected in how the elements behave when manipulated with JavaScript.

Effects and side effects of display: none:

  • the target element is taken out of the document flow (doesn't affect layout of other elements);
  • all descendants are affected (are not displayed either and cannot “snap out” of this inheritance);
  • measurements cannot be made for the target element nor for its descendants – they are not rendered at all, thus their clientWidth, clientHeight, offsetWidth, offsetHeight, scrollWidth, scrollHeight, getBoundingClientRect(), getComputedStyle(), all return 0s.

Effects and side-effects of visibility: hidden:

  • the target element is hidden from view, but is not taken out of the flow and affects layout, occupying its normal space;
  • innerText (but not innerHTML) of the target element and descendants returns empty string.

How to determine a user's IP address in node

I realize this has been answered to death, but here's a modern ES6 version I wrote that follows airbnb-base eslint standards.

const getIpAddressFromRequest = (request) => {
  let ipAddr = request.connection.remoteAddress;

  if (request.headers && request.headers['x-forwarded-for']) {
    [ipAddr] = request.headers['x-forwarded-for'].split(',');
  }

  return ipAddr;
};

The X-Forwarded-For header may contain a comma-separated list of proxy IPs. The order is client,proxy1,proxy2,...,proxyN. In the real world, people implement proxies that may supply whatever they want in this header. If you are behind a load balancer or something, you can at least trust the first IP in the list is at least whatever proxy some request came through.

Is it possible to import modules from all files in a directory, using a wildcard?

You can use async import():

import fs = require('fs');

and then:

fs.readdir('./someDir', (err, files) => {
 files.forEach(file => {
  const module = import('./' + file).then(m =>
    m.callSomeMethod();
  );
  // or const module = await import('file')
  });
});

is it possible to add colors to python output?

IDLE's console does not support ANSI escape sequences, or any other form of escapes for coloring your output.

You can learn how to talk to IDLE's console directly instead of just treating it like normal stdout and printing to it (which is how it does things like color-coding your syntax), but that's pretty complicated. The idle documentation just tells you the basics of using IDLE itself, and its idlelib library has no documentation (well, there is a single line of documentation—"(New in 2.3) Support library for the IDLE development environment."—if you know where to find it, but that isn't very helpful). So, you need to either read the source, or do a whole lot of trial and error, to even get started.


Alternatively, you can run your script from the command line instead of from IDLE, in which case you can use whatever escape sequences your terminal handles. Most modern terminals will handle at least basic 16/8-color ANSI. Many will handle 16/16, or the expanded xterm-256 color sequences, or even full 24-bit colors. (I believe gnome-terminal is the default for Ubuntu, and in its default configuration it will handle xterm-256, but that's really a question for SuperUser or AskUbuntu.)

Learning to read the termcap entries to know which codes to enter is complicated… but if you only care about a single console—or are willing to just assume "almost everything handles basic 16/8-color ANSI, and anything that doesn't, I don't care about", you can ignore that part and just hardcode them based on, e.g., this page.

Once you know what you want to emit, it's just a matter of putting the codes in the strings before printing them.

But there are libraries that can make this all easier for you. One really nice library, which comes built in with Python, is curses. This lets you take over the terminal and do a full-screen GUI, with colors and spinning cursors and anything else you want. It is a little heavy-weight for simple uses, of course. Other libraries can be found by searching PyPI, as usual.

How to display an image from a path in asp.net MVC 4 and Razor view?

In your View try like this

  <img src= "@Url.Content(Model.ImagePath)" alt="Image" />

How can I add a table of contents to a Jupyter / JupyterLab notebook?

As Ian already pointed out, there is a table-of-contents extension by minrk for the IPython Notebook. I had some trouble to make it work and made this IPython Notebook which semi-automatically generates the files for minrk's table of contents extension in Windows. It does not use the 'curl'-commands or links, but writes the *.js and *.css files directly into your IPython Notebook-profile-directory.

There is a section in the notebook called 'What you need to do' - follow it and have a nice floating table of contents : )

Here is an html version which already shows it: http://htmlpreview.github.io/?https://github.com/ahambi/140824-TOC/blob/master/A%20floating%20table%20of%20contents.htm

Add 10 seconds to a Date

I have a couple of new variants

  1. var t = new Date(Date.now() + 10000);
  2. var t = new Date(+new Date() + 10000);

No provider for Http StaticInjectorError

Add these two file in your app.module.ts

import { FileTransfer } from '@ionic-native/file-transfer';
import { File } from '@ionic-native/file';

after that declare these to in provider..

providers: [
    Api,
    Items,
    User,
    Camera,
    File,
    FileTransfer];

This is work for me.

How do I get the Session Object in Spring?

ServletRequestAttributes attr = (ServletRequestAttributes) RequestContextHolder.currentRequestAttributes();
attr.getSessionId();

Django - what is the difference between render(), render_to_response() and direct_to_template()?

Render is

def render(request, *args, **kwargs):
    """ Simple wrapper for render_to_response. """
    kwargs['context_instance'] = RequestContext(request)
    return render_to_response(*args, **kwargs)

So there is really no difference between render_to_response except it wraps your context making the template pre-processors work.

Direct to template is a generic view.

There is really no sense in using it here because there is overhead over render_to_response in the form of view function.

Undo git update-index --assume-unchanged <file>

To get undo/show dir's/files that are set to assume-unchanged run this:

git update-index --no-assume-unchanged <file>

To get a list of dir's/files that are assume-unchanged run this:

git ls-files -v|grep '^h'

how I can show the sum of in a datagridview column?

If your grid is bound to a DataTable, I believe you can just do:

// Should probably add a DBNull check for safety; but you get the idea.
long sum = (long)table.Compute("Sum(count)", "True");

If it isn't bound to a table, you could easily make it so:

var table = new DataTable();
table.Columns.Add("type", typeof(string));
table.Columns.Add("count", typeof(int));

// This will automatically create the DataGridView's columns.
dataGridView.DataSource = table;

How to check if an appSettings key exists?

Upper options gives flexible to all manner, if you know key type try parsing them bool.TryParse(ConfigurationManager.AppSettings["myKey"], out myvariable);

how to prevent adding duplicate keys to a javascript array

You can try this:

var names = ["Mike","Matt","Nancy","Adam","Jenny","Nancy","Carl"];
var uniqueNames = [];
$.each(names, function(i, el){
if($.inArray(el, uniqueNames) === -1) uniqueNames.push(el);
});

Easiest way to find duplicate values in a JavaScript array

Converting JSON to XLS/CSV in Java

You could only convert a JSON array into a CSV file.

Lets say, you have a JSON like the following :

{"infile": [{"field1": 11,"field2": 12,"field3": 13},
            {"field1": 21,"field2": 22,"field3": 23},
            {"field1": 31,"field2": 32,"field3": 33}]}

Lets see the code for converting it to csv :

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;
import org.json.CDL;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class JSON2CSV {
    public static void main(String myHelpers[]){
        String jsonString = "{\"infile\": [{\"field1\": 11,\"field2\": 12,\"field3\": 13},{\"field1\": 21,\"field2\": 22,\"field3\": 23},{\"field1\": 31,\"field2\": 32,\"field3\": 33}]}";

        JSONObject output;
        try {
            output = new JSONObject(jsonString);


            JSONArray docs = output.getJSONArray("infile");

            File file=new File("/tmp2/fromJSON.csv");
            String csv = CDL.toString(docs);
            FileUtils.writeStringToFile(file, csv);
        } catch (JSONException e) {
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }        
    }

}

Now you got the CSV generated from JSON.

It should look like this:

field1,field2,field3
11,22,33
21,22,23
31,32,33

The maven dependency was like,

<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20090211</version>
</dependency>

Update Dec 13, 2019:

Updating the answer, since now we can support complex JSON Arrays as well.

import java.nio.file.Files;
import java.nio.file.Paths;

import com.github.opendevl.JFlat;

public class FlattenJson {

    public static void main(String[] args) throws Exception {
        String str = new String(Files.readAllBytes(Paths.get("path_to_imput.json")));

        JFlat flatMe = new JFlat(str);

        //get the 2D representation of JSON document
        flatMe.json2Sheet().headerSeparator("_").getJsonAsSheet();

        //write the 2D representation in csv format
        flatMe.write2csv("path_to_output.csv");
    }

}

dependency and docs details are in link

Change Date Format(DD/MM/YYYY) in SQL SELECT Statement

There's also another way to do this-

select TO_CHAR(SA.[RequestStartDate] , 'DD/MM/YYYY') as RequestStartDate from ... ;

Batch / Find And Edit Lines in TXT file

If you are on Windows, you can use FART (Find And Replace Text). It is only 1 single *.exe file (no library needed).

All you need to is run:

fart.exe your_batch_file.bat ex3 ex5

I need to know how to get my program to output the word i typed in and also the new rearranged word using a 2D array

  1. What exactly doesn't work?
  2. Why are you using a 2d array?
  3. If you must use a 2d array:

    int numOfPairs = 10;  String[][] array = new String[numOfPairs][2]; for(int i = 0; i < array.length; i++){     for(int j = 0; j < array[i].length; j++){         array[i] = new String[2];         array[i][0] = "original word";         array[i][1] = "rearranged word";     }    } 

Does this give you a hint?

How do I format currencies in a Vue component?

You can use this example

formatPrice(value) {
  return value.toString().replace(/(\d)(?=(\d{3})+(?!\d))/g, '$1,');
},

Create a asmx web service in C# using visual studio 2013

Check your namespaces. I had and issue with that. I found that out by adding another web service to the project to dup it like you did yours and noticed the namespace was different. I had renamed it at the beginning of the project and it looks like its persisted.

See last changes in svn

If you have a working copy then svn status will help.

svn status -u -v

The --show-updates (-u) option contacts the repository and adds information about things that are out of date.

Make a Bash alias that takes a parameter?

Bash alias does not directly accept parameters. You will have to create a function.

alias does not accept parameters but a function can be called just like an alias. For example:

myfunction() {
    #do things with parameters like $1 such as
    mv "$1" "$1.bak"
    cp "$2" "$1"
}


myfunction old.conf new.conf #calls `myfunction`

By the way, Bash functions defined in your .bashrc and other files are available as commands within your shell. So for instance you can call the earlier function like this

$ myfunction original.conf my.conf

convert string array to string

string[] test = new string[2];

test[0] = "Hello ";
test[1] = "World!";

string.Join("", test);

What is the HTML unicode character for a "tall" right chevron?

Use '›'

&rsaquo; -> single right angle quote. For single left angle quote, use &lsaquo;

Checking if a list is empty with LINQ

Another idea:

if(enumerable.FirstOrDefault() != null)

However I like the Any() approach more.

In what cases will HTTP_REFERER be empty

BalusC's list is solid. One additional way this field frequently appears empty is when the user is behind a proxy server. This is similar to being behind a firewall but is slightly different so I wanted to mention it for the sake of completeness.

Serializing PHP object to JSON

In the simplest cases type hinting should work:

$json = json_encode( (array)$object );

Visual Studio 2015 or 2017 does not discover unit tests

I had the same issue. The unit test template of Visual Studio 2015 (Update 3) generates a class with TestContext property defined as follow:

    private TestContext testContextInstance;

    /// <summary>
    ///Gets or sets the test context which provides
    ///information about and functionality for the current test run.
    ///</summary>
    public TestContext TestContext
    {
        get
        {
            return testContextInstance;
        }
        set
        {
            testContextInstance = value;
        }
    }

After changing it to a public field (ungly) the test runner could discover the test.

public TestContext TestContext;

Very strange behaviour, but it was the cause of the issue in my case.

Reading a file line by line in Go

In the code bellow, I read the interests from the CLI until the user hits enter and I'm using Readline:

interests := make([]string, 1)
r := bufio.NewReader(os.Stdin)
for true {
    fmt.Print("Give me an interest:")
    t, _, _ := r.ReadLine()
    interests = append(interests, string(t))
    if len(t) == 0 {
        break;
    }
}
fmt.Println(interests)

How to open Atom editor from command line in OS X?

Another simple solution is to add /usr/local/bin to your PATH. I had the same issue, I installed shell commands (see shaheenery's response) the symlinks already existed and pointing to the correct destination (see thomax's response), however I would still get 'not found'. I'm using Korn Shell btw.

Here's what I did:

  1. Open your ~/.profile using your choice of editor (in my case $ emacs ~/.kshrc)
  2. Add this line: export PATH="/usr/local/bin:${PATH}"
  3. Save and exit
  4. Restart terminal or source ~/.profile
  5. Test $ atom -h

Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes

<p:commandXxx process> <p:ajax process> <f:ajax execute>

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="foo" action="#{bean.action}" />

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

Noted should be that the process attribute has no influence on the HTTP request payload (the amount of request parameters). Meaning, the default HTML behavior of sending "everything" contained within the HTML representation of the <h:form> will be not be affected. In case you have a large form, and want to reduce the HTTP request payload to only these absolutely necessary in processing, i.e. only these covered by process attribute, then you can set the partialSubmit attribute in PrimeFaces Ajax components as in <p:commandXxx ... partialSubmit="true"> or <p:ajax ... partialSubmit="true">. You can also configure this 'globally' by editing web.xml and add

<context-param>
    <param-name>primefaces.SUBMIT</param-name>
    <param-value>partial</param-value>
</context-param>

Alternatively, you can also use <o:form> of OmniFaces 3.0+ which defaults to this behavior.

The standard JSF equivalent to the PrimeFaces specific process is execute from <f:ajax execute>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Also, it may be useful to know that <p:commandXxx process> defaults to @form while <p:ajax process> and <f:ajax execute> defaults to @this. Finally, it's also useful to know that process supports the so-called "PrimeFaces Selectors", see also How do PrimeFaces Selectors as in update="@(.myClass)" work?


<p:commandXxx update> <p:ajax update> <f:ajax render>

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@form" />
</h:form>

(note that process attribute is omitted as that defaults to @form already)

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="foo_m bar_m" />
</h:form>

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>

(note that you should keep the IDs on message components, otherwise @(...) won't work! Again, see How do PrimeFaces Selectors as in update="@(.myClass)" work? for detail)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").


See also:

How do I get some variable from another class in Java?

Do NOT do that! setNum(num);//fix- until someone fixes your setter. Your getter should not call your setter with the uninitialized value ofnum(e.g.0`).

I suggest making a few small changes -

public static class Vars {   private int num = 5; // Default to 5.    public void setNum(int x) {     this.num = x; // actually "set" the value.   }    public int getNum() {     return num;   } } 

Difference between two DateTimes C#?

var theDiff24 = (b-a).Hours

Run a vbscript from another vbscript

As Martin's Answer didn't work at all for me ("File not found") and atesio's Answer does not allow to call two scripts which include repeating variable definitions, here is another alternative which finally worked for me:

filepath =  Chr(34) & "C:\...\helloworld.vbs" & Chr(34)
Set objshell= CreateObject("WScript.Shell") 
objshell.Run "wscript " & filepath, , True
Set objshell= Nothing

(Windows 8.1)

How can I store the result of a system command in a Perl variable?

Use backticks for system commands, which helps to store their results into Perl variables.

my $pid = 5892;
my $not = ``top -H -p $pid -n 1 | grep myprocess | wc -l`; 
print "not = $not\n";

How can we generate getters and setters in Visual Studio?

In visual studio 2019, select your properties like this:

enter image description here

Then press Ctrl+r Then press Ctrl+e

A dialog will appear showing you the preview of the changes that are going to be done to your code. If everything looks good (which it mostly will), press OK.

How to stop default link click behavior with jQuery

e.preventDefault();

from https://developer.mozilla.org/en-US/docs/Web/API/event.preventDefault

Cancels the event if it is cancelable, without stopping further propagation of the event.

Windows could not start the Apache2 on Local Computer - problem

Run the httpd.exe from the command line, as Tim mentioned. The path to PostgreSQL changed, nothing else was running on Port 80 and I didn't see anything in the error.log file.

I clone my boot drive/partition once the base is setup so I don't have to spend three days installing and retweaking everything. Turns I had reinstalled my WAPP stack and used very specific names/versions for PostgreSQL. Windows will not return a specific error message unless you run the command from the command line.

Vue 'export default' vs 'new Vue'

The first case (export default {...}) is ES2015 syntax for making some object definition available for use.

The second case (new Vue (...)) is standard syntax for instantiating an object that has been defined.

The first will be used in JS to bootstrap Vue, while either can be used to build up components and templates.

See https://vuejs.org/v2/guide/components-registration.html for more details.

What's the difference between SortedList and SortedDictionary?

Check out the MSDN page for SortedList:

From Remarks section:

The SortedList<(Of <(TKey, TValue>)>) generic class is a binary search tree with O(log n) retrieval, where n is the number of elements in the dictionary. In this, it is similar to the SortedDictionary<(Of <(TKey, TValue>)>) generic class. The two classes have similar object models, and both have O(log n) retrieval. Where the two classes differ is in memory use and speed of insertion and removal:

  • SortedList<(Of <(TKey, TValue>)>) uses less memory than SortedDictionary<(Of <(TKey, TValue>)>).
  • SortedDictionary<(Of <(TKey, TValue>)>) has faster insertion and removal operations for unsorted data, O(log n) as opposed to O(n) for SortedList<(Of <(TKey, TValue>)>).

  • If the list is populated all at once from sorted data, SortedList<(Of <(TKey, TValue>)>) is faster than SortedDictionary<(Of <(TKey, TValue>)>).

Show all tables inside a MySQL database using PHP?

How to get tables

1. SHOW TABLES

mysql> USE test;
Database changed
mysql> SHOW TABLES;
+----------------+
| Tables_in_test |
+----------------+
| t1             |
| t2             |
| t3             |
+----------------+
3 rows in set (0.00 sec)

2. SHOW TABLES IN db_name

mysql> SHOW TABLES IN another_db;
+----------------------+
| Tables_in_another_db |
+----------------------+
| t3                   |
| t4                   |
| t5                   |
+----------------------+
3 rows in set (0.00 sec)

3. Using information schema

mysql> SELECT TABLE_NAME
       FROM information_schema.TABLES
       WHERE TABLE_SCHEMA = 'another_db';
+------------+
| TABLE_NAME |
+------------+
| t3         |
| t4         |
| t5         |
+------------+
3 rows in set (0.02 sec)

to OP

you have fetched just 1 row. fix like this:

while ( $tables = $result->fetch_array())
{
    echo $tmp[0]."<br>";
}

and I think, information_schema would be better than SHOW TABLES

SELECT TABLE_NAME
FROM information_schema.TABLES 
WHERE TABLE_SCHEMA = 'your database name'

while ( $tables = $result->fetch_assoc())
{
    echo $tables['TABLE_NAME']."<br>";
}

Subversion stuck due to "previous operation has not finished"?

I have also stuck with the same issue I have tried blow:

1.Try kill the process related to svn i.e. TSVNCache.exe and TortoiseProc 2.Reverting the unversioned files and deletion of same, which I have in svn . 3.cleanup using command prompt "svn cleanup"

and finally when restarted the desktop it worked for me , So for restart of system worked for me

How to set the image from drawable dynamically in android?

Here i am setting the frnd_inactive image from drawable to the image

 imageview= (ImageView)findViewById(R.id.imageView);
 imageview.setImageDrawable(getResources().getDrawable(R.drawable.frnd_inactive));

ImportError: No module named _ssl

I am writing this solution for those who are still facing such issue and cant find the solution.

in my case, I am using

shared hosting (Cpanel Access) Linux CentOS.

I was facing this issue

No module named '_ssl'

I tried for all possible solutions but as you know sometimes things don't work for you and in hosting you don't have access to fully root and run queries. even my hosting provider did for me.. but NO GOOD RESULT.

so how I solved if you are using shared hosting and you have deployed your Django App using

Setup Python App

You only have to downgrade your Python Version, I downgraded from

Python 3.7.3

(As Python 3.7 does not have SSL module in it) To

Python 3.6.8

through Setup Python App.

Hope it will be helpful for someone with the same issue,

DataTables: Uncaught TypeError: Cannot read property 'defaults' of undefined

var datatable_jquery_script = document.createElement("script");
datatable_jquery_script.src = "vendor/datatables/jquery.dataTables.min.js";
document.body.appendChild(datatable_jquery_script);
setTimeout(function(){
    var datatable_bootstrap_script = document.createElement("script");
    datatable_bootstrap_script.src = "vendor/datatables/dataTables.bootstrap4.min.js";
    document.body.appendChild(datatable_bootstrap_script);
},100);

I used setTimeOut to make sure datatables.min.js loads first. I inspected the waterfall loading of each, bootstrap4.min.js always loads first.

Apache Proxy: No protocol handler was valid

For me all above-mentioned answers was enabled on xampp still not working. Enabling below module made virtual host work again

LoadModule slotmem_shm_module modules/mod_slotmem_shm.so

Redefine tab as 4 spaces

Make sure vartabstop is unset

set vartabstop=

Set tabstop to 4

set tabstop=4

How do I list all files of a directory?

Since version 3.4 there are builtin iterators for this which are a lot more efficient than os.listdir():

pathlib: New in version 3.4.

>>> import pathlib
>>> [p for p in pathlib.Path('.').iterdir() if p.is_file()]

According to PEP 428, the aim of the pathlib library is to provide a simple hierarchy of classes to handle filesystem paths and the common operations users do over them.

os.scandir(): New in version 3.5.

>>> import os
>>> [entry for entry in os.scandir('.') if entry.is_file()]

Note that os.walk() uses os.scandir() instead of os.listdir() from version 3.5, and its speed got increased by 2-20 times according to PEP 471.

Let me also recommend reading ShadowRanger's comment below.

How to set height property for SPAN

Why do you need a span in this case? If you want to style the height could you just use a div? You might try a div with display: inline, although that might have the same issue since you'd in effect be doing the same thing as a span.

Find out whether radio button is checked with JQuery?

You'd have to bind the click event of the checkbox, as the change event doesn't work in IE.

$('#radio_button').click(function(){
    // if ($(this).is(':checked')) alert('is checked'); 
    alert('check-checky-check was changed');
});

Now when you programmatically change the state, you have to trigger this event also:

$('#radio_button').attr("checked", "checked");
$('#radio_button').click();

How to delete an instantiated object Python?

What do you mean by delete? In Python, removing a reference (or a name) can be done with the del keyword, but if there are other names to the same object that object will not be deleted.

--> test = 3
--> print(test)
3
--> del test
--> print(test)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'test' is not defined

compared to:

--> test = 5
--> other is test  # check that both name refer to the exact same object
True
--> del test       # gets rid of test, but the object is still referenced by other
--> print(other)
5

Is it safe to use Project Lombok?

I read some opinions about the Lombok and actually I'm using it in some projects.

Well, in the first contact with Lombok I had a bad impression. After some weeks, I started to like it. But after some months I figure out a lot of tiny problems using it. So, my final impression about Lombok is not so positive.

My reasons to think in this way:

  • IDE plugin dependency. The IDE support for Lombok is through plugins. Even working good in most part of the time, you are always a hostage from this plugins to be maintained in the future releases of the IDEs and even the language version (Java 10+ will accelerate the development of the language). For example, I tried to update from Intellij IDEA 2017.3 to 2018.1 and I couldn't do that because there was some problem on the actual lombok plugin version and I needed to wait the plugin be updated... This also is a problem if you would like to use a more alternative IDE that don't have any Lombok plugin support.
  • 'Find usages' problem.. Using Lombok you don't see the generated getter, setter, constructor, builder methods and etc. So, if you are planning to find out where these methods are being used in your project by your IDE, you can't do this only looking for the class that owns this hidden methods.
  • So easy that the developers don't care to break the encapsulation. I know that it's not really a problem from Lombok. But I saw a bigger tendency from the developers to not control anymore what methods needs to be visible or not. So, many times they are just copying and pasting @Getter @Setter @Builder @AllArgsConstructor @NoArgsConstructor annotations block without thinking what methods the class really need to be exposed.
  • Builder Obssession ©. I invented this name (get off, Martin Fowler). Jokes apart, a Builder is so easy to create that even when a class have only two parameters the developers prefer to use @Builder instead of constructor or a static constructor method. Sometimes they even try to create a Builder inside the lombok Builder, creating weird situations like MyClass.builder().name("Name").build().create().
  • Barriers when refactoring. If you are using, for example, a @AllArgsConstructor and need to add one more parameter on the constructor, the IDE can't help you to add this extra parameter in all places (mostly, tests) that are instantiating the class.
  • Mixing Lombok with concrete methods. You can't use Lombok in all scenarios to create a getter/setter/etc. So, you will see these two approaches mixed in your code. You get used to this after some time, but feels like a hack on the language.

Like another answer said, if you are angry about the Java verbosity and use Lombok to deal with it, try Kotlin.

How to count items in JSON object using command line?

A simple solution is to install jshon library :

jshon -l < /tmp/test.json
2

How to compare strings in C conditional preprocessor-directives

It's simple I think you can just say

#define NAME JACK    
#if NAME == queen 

Passing a Bundle on startActivity()?

You can use the Bundle from the Intent:

Bundle extras = myIntent.getExtras();
extras.put*(info);

Or an entire bundle:

myIntent.putExtras(myBundle);

Is this what you're looking for?

Calculate RSA key fingerprint

$ ssh-add -l 

will also work on Mac OS X v10.8 (Mountain Lion) - v10.10 (Yosemite).

It also supports the option -E to specify the fingerprint format so in case MD5 is needed (it's often used, e.g. by GitHub), just add -E md5 to the command.

Print "\n" or newline characters as part of the output on terminal

If you're in control of the string, you could also use a 'Raw' string type:

>>> string = r"abcd\n"
>>> print(string)
abcd\n

Access-Control-Allow-Origin error sending a jQuery Post to Google API's

In my case the sub domain name causes the problem. Here are details

I used app_development.something.com, here underscore(_) sub domain is creating CORS error. After changing app_development to app-development it works fine.

Can't compile C program on a Mac after upgrade to Mojave

I tried almost all the posted solutions and nothing worked for me. I use Mojave OS (10.14.6) and what finally worked for me (after removing and re-installing Xcode and CLTs and SDK headers):

  1. Install Clang v8 from https://cran.r-project.org/bin/macosx/tools/
  2. Modify the following lines from ~/.R/Makevars file
CC=/usr/local/opt/llvm/bin/clang -fopenmp
CXX=/usr/local/opt/llvm/bin/clang++

with

CC=/usr/local/clang8/bin/clang -fopenmp
CXX=/usr/local/clang8/bin/clang++

Now R packages that rely on C compilers install successfully

CSS Auto hide elements after 5 seconds

based from the answer of @SW4, you could also add a little animation at the end.

_x000D_
_x000D_
body > div{_x000D_
    border:1px solid grey;_x000D_
}_x000D_
html, body, #container {_x000D_
    height:100%;_x000D_
    width:100%;_x000D_
    margin:0;_x000D_
    padding:0;_x000D_
}_x000D_
#container {_x000D_
    overflow:hidden;_x000D_
    position:relative;_x000D_
}_x000D_
#hideMe {_x000D_
    -webkit-animation: cssAnimation 5s forwards; _x000D_
    animation: cssAnimation 5s forwards;_x000D_
}_x000D_
@keyframes cssAnimation {_x000D_
    0%   {opacity: 1;}_x000D_
    90%  {opacity: 1;}_x000D_
    100% {opacity: 0;}_x000D_
}_x000D_
@-webkit-keyframes cssAnimation {_x000D_
    0%   {opacity: 1;}_x000D_
    90%  {opacity: 1;}_x000D_
    100% {opacity: 0;}_x000D_
}
_x000D_
<div>_x000D_
<div id='container'>_x000D_
    <div id='hideMe'>Wait for it...</div>_x000D_
</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Making the remaining 0.5 seconds to animate the opacity attribute. Just make sure to do the math if you're changing the length, in this case, 90% of 5 seconds leaves us 0.5 seconds to animate the opacity.

How to copy sheets to another workbook using vba?

You can simply write

Worksheets.Copy

in lieu of running a cycle. By default the worksheet collection is reproduced in a new workbook.

It is proven to function in 2010 version of XL.

Mongoose query where value is not null

$ne

selects the documents where the value of the field is not equal to the specified value. This includes documents that do not contain the field.

User.find({ "username": { "$ne": 'admin' } })

$nin

$nin selects the documents where: the field value is not in the specified array or the field does not exist.

User.find({ "groups": { "$nin": ['admin', 'user'] } })

Delete a single record from Entity Framework?

    [HttpPost]
    public JsonResult DeleteCotnact(int id)
    {
        using (MycasedbEntities dbde = new MycasedbEntities())
        {
            Contact rowcontact = (from c in dbde.Contact
                                     where c.Id == id
                                     select c).FirstOrDefault();

            dbde.Contact.Remove(rowcontact);
            dbde.SaveChanges();

            return Json(id);
        }
    }

What do you think of this, simple or not, you could also try this:

        var productrow = cnn.Product.Find(id);
        cnn.Product.Remove(productrow);
        cnn.SaveChanges();

This action could not be completed. Try Again (-22421)

I was too having this issues, I had uploaded my application and also updated it once but had no issues, but as i was uploading it for the 3rd time, i came across this issue, tried hell lot of things, scratched my head, googled it for hours, kept on trying the whole day, but nothing happened, but next day( a new light came) and my app uploaded on the first attempt.

Feel like there was some issue from apple side(be it there server, there software xCode or there mac).

So don not get dishearten if facing this problem, you can explore diff things with this problem but its just simple thing to correct this issue is to wait for some time take rest and try again.

Detect & Record Audio in Python

I believe the WAVE module does not support recording, just processing existing files. You might want to look at PyAudio for actually recording. WAV is about the world's simplest file format. In paInt16 you just get a signed integer representing a level, and closer to 0 is quieter. I can't remember if WAV files are high byte first or low byte, but something like this ought to work (sorry, I'm not really a python programmer:

from array import array

# you'll probably want to experiment on threshold
# depends how noisy the signal
threshold = 10 
max_value = 0

as_ints = array('h', data)
max_value = max(as_ints)
if max_value > threshold:
    # not silence

PyAudio code for recording kept for reference:

import pyaudio
import sys

chunk = 1024
FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 44100
RECORD_SECONDS = 5

p = pyaudio.PyAudio()

stream = p.open(format=FORMAT,
                channels=CHANNELS, 
                rate=RATE, 
                input=True,
                output=True,
                frames_per_buffer=chunk)

print "* recording"
for i in range(0, 44100 / chunk * RECORD_SECONDS):
    data = stream.read(chunk)
    # check for silence here by comparing the level with 0 (or some threshold) for 
    # the contents of data.
    # then write data or not to a file

print "* done"

stream.stop_stream()
stream.close()
p.terminate()

How to use the ConfigurationManager.AppSettings

you should use []

var x = ConfigurationManager.AppSettings["APIKey"];

How to use Session attributes in Spring-mvc

If you want to delete object after each response you don't need session,

If you want keep object during user session , There are some ways:

  1. directly add one attribute to session:

    @RequestMapping(method = RequestMethod.GET)
    public String testMestod(HttpServletRequest request){
       ShoppingCart cart = (ShoppingCart)request.getSession().setAttribute("cart",value);
       return "testJsp";
    }
    

    and you can get it from controller like this :

    ShoppingCart cart = (ShoppingCart)session.getAttribute("cart");
    
  2. Make your controller session scoped

    @Controller
    @Scope("session")
    
  3. Scope the Objects ,for example you have user object that should be in session every time:

    @Component
    @Scope("session")
    public class User
     {
        String user;
        /*  setter getter*/
      }
    

    then inject class in each controller that you want

       @Autowired
       private User user
    

    that keeps class on session.

  4. The AOP proxy injection : in spring -xml:

    <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
    
      <bean id="user"    class="com.User" scope="session">     
          <aop:scoped-proxy/>
      </bean>
    </beans>
    

    then inject class in each controller that you want

    @Autowired
    private User user
    

5.Pass HttpSession to method:

 String index(HttpSession session) {
            session.setAttribute("mySessionAttribute", "someValue");
            return "index";
        }

6.Make ModelAttribute in session By @SessionAttributes("ShoppingCart"):

  public String index (@ModelAttribute("ShoppingCart") ShoppingCart shoppingCart, SessionStatus sessionStatus) {
//Spring V4
//you can modify session status  by sessionStatus.setComplete();
}

or you can add Model To entire Controller Class like,

@Controller
    @SessionAttributes("ShoppingCart")
    @RequestMapping("/req")
    public class MYController {

        @ModelAttribute("ShoppingCart")
        public Visitor getShopCart (....) {
            return new ShoppingCart(....); //get From DB Or Session
        }  
      }

each one has advantage and disadvantage:

@session may use more memory in cloud systems it copies session to all nodes, and direct method (1 and 5) has messy approach, it is not good to unit test.

To access session jsp

<%=session.getAttribute("ShoppingCart.prop")%>

in Jstl :

<c:out value="${sessionScope.ShoppingCart.prop}"/>

in Thymeleaf:

<p th:text="${session.ShoppingCart.prop}" th:unless="${session == null}"> . </p>

jQuery: Scroll down page a set increment (in pixels) on click?

You can do that using animate like in the following link:

http://blog.freelancer-id.com/index.php/2009/03/26/scroll-window-smoothly-in-jquery

If you want to do it using scrollTo plugin, then take a look the following:

How to scroll the window using JQuery $.scrollTo() function

Repeat command automatically in Linux

If you want to do something a specific number of times you can always do this:

repeat 300 do my first command here && sleep 1.5

How to lose margin/padding in UITextView?

This workaround was written in 2009 when IOS 3.0 was released. It no longer applies.

I ran into the exact same problem, in the end I had to wind up using

nameField.contentInset = UIEdgeInsetsMake(-4,-8,0,0);

where nameField is a UITextView. The font I happened to be using was Helvetica 16 point. Its only a custom solution for the particular field size I was drawing. This makes the left offset flush with the left side, and the top offset where I want it for the box its draw in.

In addition, this only seems to apply to UITextViews where you are using the default aligment, ie.

nameField.textAlignment = NSTextAlignmentLeft;

Align to the right for example and the UIEdgeInsetsMake seems to have no impact on the right edge at all.

At very least, using the .contentInset property allows you to place your fields with the "correct" positions, and accommodate the deviations without offsetting your UITextViews.

How do I pass JavaScript values to Scriptlet in JSP?

If you are saying you wanna pass javascript value from one jsp to another in javascript then use URLRewriting technique to pass javascript variable to next jsp file and access that in next jsp in request object.

Other wise you can't do it.

jQuery: click function exclude children.

Here is an example. Green square is parent and yellow square is child element.

Hope that this helps.

_x000D_
_x000D_
var childElementClicked;_x000D_
_x000D_
$("#parentElement").click(function(){_x000D_
_x000D_
  $("#childElement").click(function(){_x000D_
     childElementClicked = true;_x000D_
  });_x000D_
_x000D_
  if( childElementClicked != true ) {_x000D_
_x000D_
   // It is clicked on parent but not on child._x000D_
      // Now do some action that you want._x000D_
      alert('Clicked on parent');_x000D_
   _x000D_
  }else{_x000D_
      alert('Clicked on child');_x000D_
    }_x000D_
    _x000D_
    childElementClicked = false;_x000D_
 _x000D_
});
_x000D_
#parentElement{_x000D_
width:200px;_x000D_
height:200px;_x000D_
background-color:green;_x000D_
position:relative;_x000D_
}_x000D_
_x000D_
#childElement{_x000D_
margin-top:50px;_x000D_
margin-left:50px;_x000D_
width:100px;_x000D_
height:100px;_x000D_
background-color:yellow;_x000D_
position:absolute;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<div id="parentElement">_x000D_
  <div id="childElement">_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_