SyntaxFix

Programs & Examples On #Icollection

The ICollection interface is the base interface for classes in the System.Collections namespace. It defines size, enumerators, and synchronization methods for all non-generic collections

Why use ICollection and not IEnumerable or List<T> on many-many/one-many relationships?

ICollection<T> is used because the IEnumerable<T> interface provides no way of adding items, removing items, or otherwise modifying the collection.

Using a list as a data source for DataGridView

First, I don't understand why you are adding all the keys and values count times, Index is never used.

I tried this example :

        var source = new BindingSource();
        List<MyStruct> list = new List<MyStruct> { new MyStruct("fff", "b"),  new MyStruct("c","d") };
        source.DataSource = list;
        grid.DataSource = source;

and that work pretty well, I get two columns with the correct names. MyStruct type exposes properties that the binding mechanism can use.

    class MyStruct
   {
    public string Name { get; set; }
    public string Adres { get; set; }


    public MyStruct(string name, string adress)
    {
        Name = name;
        Adres = adress;
    }
  }

Try to build a type that takes one key and value, and add it one by one. Hope this helps.

Print a file, skipping the first X lines, in Bash

Use the sed delete command with a range address. For example:

sed 1,100d file.txt # Print file.txt omitting lines 1-100.

Alternatively, if you want to only print a known range, use the print command with the -n flag:

sed -n 201,300p file.txt # Print lines 201-300 from file.txt

This solution should work reliably on all Unix systems, regardless of the presence of GNU utilities.

Colors in JavaScript console

This library is fantastic:

https://github.com/adamschwartz/log

Use Markdown for log messages.

Python Pandas replicate rows in dataframe

Appending and concatenating is usually slow in Pandas so I recommend just making a new list of the rows and turning that into a dataframe (unless appending a single row or concatenating a few dataframes). 

import pandas as pd

df = pd.DataFrame([
[1,1,'2010-02-05',24924.5,False],
[1,1,'2010-02-12',46039.49,True],
[1,1,'2010-02-19',41595.55,False],
[1,1,'2010-02-26',19403.54,False],
[1,1,'2010-03-05',21827.9,False],
[1,1,'2010-03-12',21043.39,False],
[1,1,'2010-03-19',22136.64,False],
[1,1,'2010-03-26',26229.21,False],
[1,1,'2010-04-02',57258.43,False]
], columns=['Store','Dept','Date','Weekly_Sales','IsHoliday'])

temp_df = []
for row in df.itertuples(index=False):
    if row.IsHoliday:
        temp_df.extend([list(row)]*5)
    else:
        temp_df.append(list(row))

df = pd.DataFrame(temp_df, columns=df.columns)

Heroku: How to push different local Git branches to Heroku/master

I think it should be

push = refs/heads/*:refs/heads/*

instead...

Where are logs located?

In Laravel 6, by default the logs are in:

storage/logs/laravel.log

This application has no explicit mapping for /error

Ensure that you have jasper and jstl in the list of dependencies:

_x000D_
_x000D_ 
<dependency>_x000D_
    <groupId>org.apache.tomcat.embed</groupId>_x000D_
    <artifactId>tomcat-embed-jasper</artifactId>_x000D_
    <scope>provided</scope>_x000D_
</dependency>_x000D_
<dependency>_x000D_
    <groupId>javax.servlet</groupId>_x000D_
    <artifactId>jstl</artifactId>_x000D_
</dependency>
_x000D_
_x000D_
_x000D_

Here is a working starter project - https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples/spring-boot-sample-web-jsp

Author: Biju Kunjummen

Is there an easy way to strike through text in an app widget?

I've done this on a regular (local) TextView, and it should work on the remote variety since the docs list the method as equivalent between the two:

remote_text_view.setText(Html.fromHtml("This is <del>crossed off</del>."));

What is the equivalent of the C++ Pair<L,R> in Java?

The answer by @Andreas Krey is actually good. Anything Java makes difficult, you probably shouldn't be doing.

The most common uses of Pair's in my experience have been multiple return values from a method and as VALUES in a hashmap (often indexed by strings).

In the latter case, I recently used a data structure, something like this:

class SumHolder{MyObject trackedObject, double sum};

There is your entire "Pair" class, pretty much the same amount of code as a generic "Pair" but with the advantage of descriptive names. It can be defined in-line right in the method it's used which will eliminate typical problems with public variables and the like. In other words, it's absolutely better than a pair for this usage (due to the named members) and no worse.

If you actually want a "Pair" for the key of a hashmap you are essentially creating a double-key index. I think this may be the one case where a "Pair" is significantly less code. It's not really easier because you could have eclipse generate equals/hash on your little data class, but it would be a good deal more code. Here a Pair would be a quick fix, but if you need a double-indexed hash who's to say you don't need an n-indexed hash? The data class solution will scale up, the Pair will not unless you nest them!

So the second case, returning from a method, is a bit harder. Your class needs more visibility (the caller needs to see it too). You can define it outside the method but inside the class exactly as above. At that point your method should be able to return a MyClass.SumHolder object. The caller gets to see the names of the returned objects, not just a "Pair". Note again that the "Default" security of package level is pretty good--it's restrictive enough that you shouldn't get yourself into too much trouble. Better than a "Pair" object anyway.

The other case I can see a use for Pairs is a public api with return values for callers outside your current package. For this I'd just create a true object--preferably immutable. Eventually a caller will share this return value and having it mutable could be problematic. This is another case of the Pair object being worse--most pairs cannot be made immutable.

Another advantage to all these cases--the java class expands, my sum class needed a second sum and a "Created" flag by the time I was done, I would have had to throw away the Pair and gone with something else, but if the pair made sense, my class with 4 values still makes at least as much sense.

How to get GMT date in yyyy-mm-dd hh:mm:ss in PHP

gmdate() is doing exactly what you asked for.

Look at formats here: http://php.net/manual/en/function.gmdate.php

Swift convert unix time to date and time

For me: Converting timestamps coming from API to a valid date :

`let date = NSDate.init(fromUnixTimestampNumber: timesTamp /* i.e 1547398524000 */) as Date?`

How do you determine the ideal buffer size when using FileInputStream?

You could use the BufferedStreams/readers and then use their buffer sizes.

I believe the BufferedXStreams are using 8192 as the buffer size, but like Ovidiu said, you should probably run a test on a whole bunch of options. Its really going to depend on the filesystem and disk configurations as to what the best sizes are.

Get the current first responder without using a private API

Using Swift and with a specific UIView object this might help:

func findFirstResponder(inView view: UIView) -> UIView? {
    for subView in view.subviews as! [UIView] {
        if subView.isFirstResponder() {
            return subView
        }
        
        if let recursiveSubView = self.findFirstResponder(inView: subView) {
            return recursiveSubView
        }
    }
    
    return nil
}

Just place it in your UIViewController and use it like this:

let firstResponder = self.findFirstResponder(inView: self.view)

Take note that the result is an Optional value so it will be nil in case no firstResponder was found in the given views subview hierarchy.

PHP multiline string with PHP

You don't need to output php tags:

<?php 
    if ( has_post_thumbnail() ) 
    {
        echo '<div class="gridly-image"><a href="'. the_permalink() .'">'. the_post_thumbnail('summary-image', array('class' => 'overlay', 'title'=> the_title('Read Article ',' now',false) )) .'</a></div>';
    }

    echo '<div class="date">
              <span class="day">'. the_time('d') .'</span>
              <div class="holder">
                <span class="month">'. the_time('M') .'</span>
                <span class="year">'. the_time('Y') .'</span>
              </div>
          </div>';
?>

When do I use super()?

I just tried it, commenting super(); does the same thing without commenting it as @Mark Peters said

package javaapplication6;

/**
 *
 * @author sborusu
 */
public class Super_Test {
    Super_Test(){
        System.out.println("This is super class, no object is created");
    }
}
class Super_sub extends Super_Test{
    Super_sub(){
       super();
       System.out.println("This is sub class, object is created");
    }
    public static void main(String args[]){
        new Super_sub();
    }
}

pandas unique values multiple columns

here's another way


import numpy as np
set(np.concatenate(df.values))

Python 3 print without parenthesis

Use Autohotkey to make a macro. AHK is free and dead simple to install. www.autohotkey.com

You could assign the macro to, say, alt-p:

!p::send print(){Left}

That will make alt-p put out print() and move your cursor to inside the parens.

Or, even better, to directly solve your problem, you define an autoreplace and limit its scope to when the open file has the .py extension:

#IfWinActive .py            ;;; scope limiter
:b*:print ::print(){Left}   ;;; I forget what b* does. The rest should be clear 
#IfWinActive                ;;; remove the scope limitation

This is a guaranteed, painless, transparent solution.

How to dismiss AlertDialog in android

To dismiss or cancel AlertDialog.Builder

dialog.setNegativeButton("?????", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        dialogInterface.dismiss();
                    }
                });

you call dismiss() on the dialog interface

Reference - What does this regex mean?

The Stack Overflow Regular Expressions FAQ

See also a lot of general hints and useful links at the tag details page.

Online tutorials

Quantifiers

Character Classes

Escape Sequences

Anchors

(Also see "Flavor-Specific Information ? Java ? The functions in Matcher")

Groups

Lookarounds

Modifiers

flag modifier flavors
c current position
e expression
g global most
i case-insensitive most
m multiline
m (non)multiline
o once
S study
s single line unsupported: (workaround) |
U ungreedy
u unicode most
x whitespace-extended most
y sticky ?

Other:

Common Tasks

Advanced Regex-Fu

Flavor-Specific Information

(Except for those marked with *, this section contains non-Stack Overflow links.)

General information

(Links marked with * are non-Stack Overflow links.)

Examples of regex that can cause regex engine to fail

Tools: Testers and Explainers

(This section contains non-Stack Overflow links.)

Convert an image to grayscale

There's a static method in ToolStripRenderer class, named CreateDisabledImage. Its usage is as simple as:

Bitmap c = new Bitmap("filename");
Image d = ToolStripRenderer.CreateDisabledImage(c);

It uses a little bit different matrix than the one in the accepted answer and additionally multiplies it by a transparency of value 0.7, so the effect is slightly different than just grayscale, but if you want to just get your image grayed, it's the simplest and best solution.

How to send email to multiple recipients using python smtplib?

The solution below worked for me. It successfully sends an email to multiple recipients, including "CC" and "BCC."

toaddr = ['mailid_1','mailid_2']
cc = ['mailid_3','mailid_4']
bcc = ['mailid_5','mailid_6']
subject = 'Email from Python Code'
fromaddr = 'sender_mailid'
message = "\n  !! Hello... !!"

msg['From'] = fromaddr
msg['To'] = ', '.join(toaddr)
msg['Cc'] = ', '.join(cc)
msg['Bcc'] = ', '.join(bcc)
msg['Subject'] = subject

s.sendmail(fromaddr, (toaddr+cc+bcc) , message)

Changing font size and direction of axes text in ggplot2

Ditto @Drew Steen on the use of theme(). Here are common theme attributes for axis text and titles.

ggplot(mtcars, aes(x = factor(cyl), y = mpg))+
  geom_point()+
  theme(axis.text.x = element_text(color = "grey20", size = 20, angle = 90, hjust = .5, vjust = .5, face = "plain"),
        axis.text.y = element_text(color = "grey20", size = 12, angle = 0, hjust = 1, vjust = 0, face = "plain"),  
        axis.title.x = element_text(color = "grey20", size = 12, angle = 0, hjust = .5, vjust = 0, face = "plain"),
        axis.title.y = element_text(color = "grey20", size = 12, angle = 90, hjust = .5, vjust = .5, face = "plain"))

jQuery keypress() event not firing?

e.which doesn't work in IE try e.keyCode, also you probably want to use keydown() instead of keypress() if you are targeting IE.

See http://unixpapa.com/js/key.html for more information.

How to find memory leak in a C++ code/project?

You can use some techniques in your code to detect memory leak. The most common and most easy way to detect is, define a macro say, DEBUG_NEW and use it, along with predefined macros like __FILE__ and __LINE__ to locate the memory leak in your code. These predefined macros tell you the file and line number of memory leaks.

DEBUG_NEW is just a MACRO which is usually defined as:

#define DEBUG_NEW new(__FILE__, __LINE__)
#define new DEBUG_NEW

So that wherever you use new, it also can keep track of the file and line number which could be used to locate memory leak in your program.

And __FILE__, __LINE__ are predefined macros which evaluate to the filename and line number respectively where you use them!

Read the following article which explains the technique of using DEBUG_NEW with other interesting macros, very beautifully:

A Cross-Platform Memory Leak Detector

From Wikpedia,

Debug_new refers to a technique in C++ to overload and/or redefine operator new and operator delete in order to intercept the memory allocation and deallocation calls, and thus debug a program for memory usage. It often involves defining a macro named DEBUG_NEW, and makes new become something like new(_FILE_, _LINE_) to record the file/line information on allocation. Microsoft Visual C++ uses this technique in its Microsoft Foundation Classes. There are some ways to extend this method to avoid using macro redefinition while still able to display the file/line information on some platforms. There are many inherent limitations to this method. It applies only to C++, and cannot catch memory leaks by C functions like malloc. However, it can be very simple to use and also very fast, when compared to some more complete memory debugger solutions.

How do I configure modprobe to find my module?

You can make a symbolic link of your module to the standard path, so depmod will see it and you'll be able load it as any other module.

sudo ln -s /path/to/module.ko /lib/modules/`uname -r`
sudo depmod -a
sudo modprobe module

If you add the module name to /etc/modules it will be loaded any time you boot.

Anyway I think that the proper configuration is to copy the module to the standard paths.

Playing a MP3 file in a WinForm application

1) The most simple way would be using WMPLib

WMPLib.WindowsMediaPlayer Player;

private void PlayFile(String url)
{
    Player = new WMPLib.WindowsMediaPlayer();
    Player.PlayStateChange += Player_PlayStateChange;
    Player.URL = url;
    Player.controls.play();
}

private void Player_PlayStateChange(int NewState)
{
    if ((WMPLib.WMPPlayState)NewState == WMPLib.WMPPlayState.wmppsStopped)
    {
        //Actions on stop
    }
}

2) Alternatively you can use the open source library NAudio. It can play mp3 files using different methods and actually offers much more than just playing a file.

This is as simple as

using NAudio;
using NAudio.Wave;

IWavePlayer waveOutDevice = new WaveOut();
AudioFileReader audioFileReader = new AudioFileReader("Hadouken! - Ugly.mp3");

waveOutDevice.Init(audioFileReader);
waveOutDevice.Play();

Don't forget to dispose after the stop

waveOutDevice.Stop();
audioFileReader.Dispose();
waveOutDevice.Dispose();

Difference between dates in JavaScript

 
Date.prototype.addDays = function(days) {

   var dat = new Date(this.valueOf())
   dat.setDate(dat.getDate() + days);
   return dat;
}

function getDates(startDate, stopDate) {

  var dateArray = new Array();
  var currentDate = startDate;
  while (currentDate <= stopDate) {
    dateArray.push(currentDate);
    currentDate = currentDate.addDays(1);
  }
  return dateArray;
}

var dateArray = getDates(new Date(), (new Date().addDays(7)));

for (i = 0; i < dateArray.length; i ++ ) {
  //  alert (dateArray[i]);

    date=('0'+dateArray[i].getDate()).slice(-2);
    month=('0' +(dateArray[i].getMonth()+1)).slice(-2);
    year=dateArray[i].getFullYear();
    alert(date+"-"+month+"-"+year );
}

How do I update Anaconda?

On Mac, open a terminal and run the following two commands.

conda update conda
conda update anaconda

Make sure to run each command multiple times to update to the current version.

How to get file name from file path in android

Other Way is:

String[] parts = selectedFilePath.split("/");
    final String fileName = parts[parts.length-1];

Append an int to a std::string

You cannot cast an int to a char* to get a string. Try this:

std::ostringstream sstream;
sstream << "select logged from login where id = " << ClientID;
std::string query = sstream.str();

stringstream reference

How do I get the month and day with leading 0's in SQL? (e.g. 9 => 09)

SQL Server 2012+ (for both month and day):

SELECT FORMAT(GetDate(),'MMdd')

If you decide you want the year too, use: 

SELECT FORMAT(GetDate(),'yyyyMMdd')

SVN commit command

Step1. $ cd [your working path of code]

Step2. $ svn commit [your server path ] -m 'Add commit message'

For help use $ svn help commit

How to increase icons size on Android Home Screen?

Unless you write your own Homescreen launcher or use an existing one from Goolge Play, there's "no way" to resize icons.

Well, "no way" does not mean its impossible:

  • As said, you can write your own launcher as discussed in Stackoverflow.
  • You can resize elements on the home screen, but these elements are AppWidgets. Since API level 14 they can be resized and user can - in limits - change the size. But that are Widgets not Shortcuts for launching icons.

get url content PHP

Use cURL,

Check if you have it via phpinfo();

And for the code:

function getHtml($url, $post = null) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    if(!empty($post)) {
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
    } 
    $result = curl_exec($ch);
    curl_close($ch);
    return $result;
}

Creating JSON on the fly with JObject

Sooner or later you will have property with special character. You can either use index or combination of index and property.

dynamic jsonObject = new JObject();
jsonObject["Create-Date"] = DateTime.Now; //<-Index use
jsonObject.Album = "Me Against the world"; //<- Property use
jsonObject["Create-Year"] = 1995; //<-Index use
jsonObject.Artist = "2Pac"; //<-Property use

What is the difference between \r and \n?

They're different characters. \r is carriage return, and \n is line feed.

On "old" printers, \r sent the print head back to the start of the line, and \n advanced the paper by one line. Both were therefore necessary to start printing on the next line.

Obviously that's somewhat irrelevant now, although depending on the console you may still be able to use \r to move to the start of the line and overwrite the existing text.

More importantly, Unix tends to use \n as a line separator; Windows tends to use \r\n as a line separator and Macs (up to OS 9) used to use \r as the line separator. (Mac OS X is Unix-y, so uses \n instead; there may be some compatibility situations where \r is used instead though.)

For more information, see the Wikipedia newline article.

EDIT: This is language-sensitive. In C# and Java, for example, \n always means Unicode U+000A, which is defined as line feed. In C and C++ the water is somewhat muddier, as the meaning is platform-specific. See comments for details.

Html5 Full screen video

 
    if (vi_video[0].exitFullScreen) vi_video[0].exitFullScreen();
    else if (vi_video[0].webkitExitFullScreen) vi_video[0].webkitExitFullScreen();
    else if (vi_video[0].mozExitFullScreen) vi_video[0].mozExitFullScreen();
    else if (vi_video[0].oExitFullScreen) vi_video[0].oExitFullScreen();
    else if (vi_video[0].msExitFullScreen) vi_video[0].msExitFullScreen();
    else { vi_video.parent().append(vi_video.remove()); }

How to remove unused imports from Eclipse

Use ALT + CTRL + O. It will organize all the imports. You can find various other options in the "Code" Menu.

EDIT: Sorry it is CTRL + SHIFT + O

How large is a DWORD with 32- and 64-bit code?

It is defined as:

typedef unsigned long       DWORD;

However, according to the MSDN:

On 32-bit platforms, long is synonymous with int.

Therefore, DWORD is 32bit on a 32bit operating system. There is a separate define for a 64bit DWORD:

typdef unsigned _int64 DWORD64;

Hope that helps.

How to parse SOAP XML?

 
$xml = '<?xml version="1.0" encoding="utf-8"?>
                <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
                  <soap:Body>
                    <PaymentNotification xmlns="http://apilistener.envoyservices.com">
                      <payment>
                        <uniqueReference>ESDEUR11039872</uniqueReference>
                        <epacsReference>74348dc0-cbf0-df11-b725-001ec9e61285</epacsReference>
                        <postingDate>2010-11-15T15:19:45</postingDate>
                        <bankCurrency>EUR</bankCurrency>
                        <bankAmount>1.00</bankAmount>
                        <appliedCurrency>EUR</appliedCurrency>
                        <appliedAmount>1.00</appliedAmount>
                        <countryCode>ES</countryCode>
                        <bankInformation>Sean Wood</bankInformation>
                  <merchantReference>ESDEUR11039872</merchantReference>
                   </payment>
                    </PaymentNotification>
                  </soap:Body>
                </soap:Envelope>';
        $doc = new DOMDocument();
        $doc->loadXML($xml);
        echo $doc->getElementsByTagName('postingDate')->item(0)->nodeValue;
        die;

Result is:

2010-11-15T15:19:45

Angular 5 Scroll to top on every Route click

EDIT: For Angular 6+, please use Nimesh Nishara Indimagedara's answer mentioning:

RouterModule.forRoot(routes, {
    scrollPositionRestoration: 'enabled'
});

Original Answer:

If all fails, then create some empty HTML element (eg: div) at the top (or desired scroll to location) with id="top" on template (or parent template):

<div id="top"></div>

And in component: 

  ngAfterViewInit() {
    // Hack: Scrolls to top of Page after page view initialized
    let top = document.getElementById('top');
    if (top !== null) {
      top.scrollIntoView();
      top = null;
    }
  }

Get a particular cell value from HTML table using JavaScript

I found this as an easiest way to add row . The awesome thing about this is that it doesn't change the already present table contents even if it contains input elements . 

row = `<tr><td><input type="text"></td></tr>`
$("#table_body tr:last").after(row) ;

Here #table_body is the id of the table body tag .

Best practice for localization and globalization of strings and labels

jQuery.i18n is a lightweight jQuery plugin for enabling internationalization in your web pages. It allows you to package custom resource strings in ‘.properties’ files, just like in Java Resource Bundles. It loads and parses resource bundles (.properties) based on provided language or language reported by browser.

to know more about this take a look at the How to internationalize your pages using JQuery?

How can I check if my Element ID has focus?

Write below code in script and also add jQuery library

var getElement = document.getElementById('myID');

if (document.activeElement === getElement) {
        $(document).keydown(function(event) {
            if (event.which === 40) {
                console.log('keydown pressed')
            }
        });
    }

Thank you...

using .join method to convert array to string without commas

The .join() method has a parameter for the separator string. If you want it to be empty instead of the default comma, use

arr.join("");

How to generate a range of numbers between two numbers?

Select non-persisted values with the VALUES keyword. Then use JOINs to generate lots and lots of combinations (can be extended to create hundreds of thousands of rows and beyond).

SELECT ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n
FROM (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) ones(n),
     (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) tens(n),
     (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) hundreds(n),
     (VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) thousands(n)
WHERE ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n BETWEEN @userinput1 AND @userinput2
ORDER BY 1

Demo

A shorter alternative, that is not as easy to understand:

WITH x AS (SELECT n FROM (VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) v(n))
SELECT ones.n + 10*tens.n + 100*hundreds.n + 1000*thousands.n
FROM x ones,     x tens,      x hundreds,       x thousands
ORDER BY 1

Demo

send Content-Type: application/json post with node.js

For some reason only this worked for me today. All other variants ended up in bad json error from API.

Besides, yet another variant for creating required POST request with JSON payload.

_x000D_
_x000D_ 
request.post({_x000D_
    uri: 'https://www.googleapis.com/urlshortener/v1/url',_x000D_
    headers: {'Content-Type': 'application/json'},_x000D_
    body: JSON.stringify({"longUrl": "http://www.google.com/"})_x000D_
});
_x000D_
_x000D_
_x000D_

Server.MapPath("."), Server.MapPath("~"), Server.MapPath(@"\"), Server.MapPath("/"). What is the difference?

Server.MapPath specifies the relative or virtual path to map to a physical directory.

  • Server.MapPath(".")1 returns the current physical directory of the file (e.g. aspx) being executed
  • Server.MapPath("..") returns the parent directory
  • Server.MapPath("~") returns the physical path to the root of the application
  • Server.MapPath("/") returns the physical path to the root of the domain name (is not necessarily the same as the root of the application)

An example:

Let's say you pointed a web site application (http://www.example.com/) to

C:\Inetpub\wwwroot

and installed your shop application (sub web as virtual directory in IIS, marked as application) in 

D:\WebApps\shop

For example, if you call Server.MapPath() in following request:

http://www.example.com/shop/products/GetProduct.aspx?id=2342

then:

  • Server.MapPath(".")1 returns D:\WebApps\shop\products
  • Server.MapPath("..") returns D:\WebApps\shop
  • Server.MapPath("~") returns D:\WebApps\shop
  • Server.MapPath("/") returns C:\Inetpub\wwwroot
  • Server.MapPath("/shop") returns D:\WebApps\shop

If Path starts with either a forward slash (/) or backward slash (\), the MapPath() returns a path as if Path was a full, virtual path.

If Path doesn't start with a slash, the MapPath() returns a path relative to the directory of the request being processed.

Note: in C#, @ is the verbatim literal string operator meaning that the string should be used "as is" and not be processed for escape sequences.

Footnotes

  1. Server.MapPath(null) and Server.MapPath("") will produce this effect too.

How do I call a non-static method from a static method in C#?

You can use call method by like this : Foo.Data2()

public class Foo
{
    private static Foo _Instance;

    private Foo()
    {
    }

    public static Foo GetInstance()
    {
        if (_Instance == null)
            _Instance = new Foo();
        return _Instance;
    }

    protected void Data1()
    {
    }

    public static void Data2()
    {
        GetInstance().Data1();
    }
}

Py_Initialize fails - unable to load the file system codec

Ran into the same thing trying to install brew's python3 under Mac OS! The issue here is that in Mac OS, homebrew puts the "real" python a whole layer deeper than you think. You would think from the homebrew output that

$ echo $PYTHONHOME
/usr/local/Cellar/python3/3.6.2/
$ echo $PYTHONPATH
/usr/local/Cellar/python3/3.6.2/bin

would be correct, but invoking $PYTHONPATH/python3 immediately crashes with the abort 6 "can't find encodings." This is because although that $PYTHONHOME looks like a complete installation, having a bin, lib etc, it is NOT the actual Python, which is in a Mac OS "Framework". Do this:

PYTHONHOME=/usr/local/Cellar/python3/3.x.y/Frameworks/Python.framework/Versions/3.x
PYTHONPATH=$PYTHONHOME/bin

(substituting version numbers as appropriate) and it will work fine.

Error importing SQL dump into MySQL: Unknown database / Can't create database

I create the database myself using the command line. Then try to import again, it works.

How do you automatically set text box to Uppercase?

I think the most robust solution that will insure that it is posted in uppercase is to use the oninput method inline like:

_x000D_
_x000D_ 
<input oninput="this.value = this.value.toUpperCase()" />
_x000D_
_x000D_
_x000D_

EDIT

Some people have been complaining that the cursor jumps to the end when editing the value, so this slightly expanded version should resolve that

_x000D_
_x000D_ 
<input oninput="let p=this.selectionStart;this.value=this.value.toUpperCase();this.setSelectionRange(p, p);" />
_x000D_
_x000D_
_x000D_

How do you get a directory listing sorted by creation date in python?

Alex Coventry's answer will produce an exception if the file is a symlink to an unexistent file, the following code corrects that answer:

import time
import datetime
sorted(filter(os.path.isfile, os.listdir('.')), 
    key=lambda p: os.path.exists(p) and os.stat(p).st_mtime or time.mktime(datetime.now().timetuple())

When the file doesn't exist, now() is used, and the symlink will go at the very end of the list.

how to select rows based on distinct values of A COLUMN only

Try this - you need a CTE (Common Table Expression) that partitions (groups) your data by distinct e-mail address, and sorts each group by ID - smallest first. Then you just select the first entry for each group - that should give you what you're looking for:

;WITH DistinctMails AS
(
    SELECT ID, MailID, EMailAddress, NAME,
        ROW_NUMBER() OVER(PARTITION BY EMailAddress ORDER BY ID) AS 'RowNum'
    FROM dbo.YourMailTable
)
SELECT *
FROM DistinctMails
WHERE RowNum = 1

This works on SQL Server 2005 and newer (you didn't mention what version you're using...)

HTTP response header content disposition for attachments

Problems

The code has the following issues:

  • An Ajax call (<a4j:commandButton .../>) does not work with attachments.
  • Creating the output content must happen first.
  • Displaying the error messages also cannot use Ajax-based a4j tags.

Solution

  1. Change <a4j:commandButton .../> to <h:commandButton .../>.
  2. Update the source code:
    1. Change bw.write( getDomainDocument() ); to bw.write( document );.
    2. Add String document = getDomainDocument(); to the first line of the try/catch.
  3. Change the <a4j:outputPanel.../> (not shown) to <h:messages showDetail="false"/>.

Essentially, remove all the Ajax facilities related to the commandButton. It is still possible to display error messages and leverage the RichFaces UI style.

References

How do I get the type of a variable?

Usually, wanting to find the type of a variable in C++ is the wrong question. It tends to be something you carry along from procedural languages like for instance C or Pascal.

If you want to code different behaviours depending on type, try to learn about e.g. function overloading and object inheritance. This won't make immediate sense on your first day of C++, but keep at it.

pySerial write() won't take my string

I had the same "TypeError: an integer is required" error message when attempting to write. Thanks, the .encode() solved it for me. I'm running python 3.4 on a Dell D530 running 32 bit Windows XP Pro.

I'm omitting the com port settings here:

>>>import serial

>>>ser = serial.Serial(5)

>>>ser.close()

>>>ser.open()

>>>ser.write("1".encode())

1

>>>

List of tables, db schema, dump etc using the Python sqlite3 API

Some might find my function useful if you just want to print out all of the tables and columns in your db.

In the loop, I query each TABLE with LIMIT 0 so it just returns the header info without all the data. You make an empty df out of it, and use the iterable df.columns to print each column name out.

conn = sqlite3.connect('example.db')
c = conn.cursor()

def table_info(c, conn):
    '''
    prints out all of the columns of every table in db
    c : cursor object
    conn : database connection object
    '''
    tables = c.execute("SELECT name FROM sqlite_master WHERE type='table';").fetchall()
    for table_name in tables:
        table_name = table_name[0] # tables is a list of single item tuples
        table = pd.read_sql_query("SELECT * from {} LIMIT 0".format(table_name), conn)
        print(table_name)
        for col in table.columns:
            print('\t-' + col)
        print()

table_info(c, conn)

Results will be:

table1
    -column1
    -column2

table2
    -column1
    -column2
    -column3 

etc.

What's the difference between "static" and "static inline" function?

By default, an inline definition is only valid in the current translation unit.

If the storage class is extern, the identifier has external linkage and the inline definition also provides the external definition.

If the storage class is static, the identifier has internal linkage and the inline definition is invisible in other translation units.

If the storage class is unspecified, the inline definition is only visible in the current translation unit, but the identifier still has external linkage and an external definition must be provided in a different translation unit. The compiler is free to use either the inline or the external definition if the function is called within the current translation unit.

As the compiler is free to inline (and to not inline) any function whose definition is visible in the current translation unit (and, thanks to link-time optimizations, even in different translation units, though the C standard doesn't really account for that), for most practical purposes, there's no difference between static and static inline function definitions.

The inline specifier (like the register storage class) is only a compiler hint, and the compiler is free to completely ignore it. Standards-compliant non-optimizing compilers only have to honor their side-effects, and optimizing compilers will do these optimizations with or without explicit hints.

inline and register are not useless, though, as they instruct the compiler to throw errors when the programmer writes code that would make the optimizations impossible: An external inline definition can't reference identifiers with internal linkage (as these would be unavailable in a different translation unit) or define modifiable local variables with static storage duration (as these wouldn't share state accross translation units), and you can't take addresses of register-qualified variables.

Personally, I use the convention to mark static function definitions within headers also inline, as the main reason for putting function definitions in header files is to make them inlinable.

In general, I only use static inline function and static const object definitions in addition to extern declarations within headers.

I've never written an inline function with a storage class different from static.

Update Angular model after setting input value with jQuery

If you are using IE, you have to use: input.trigger("change");

How to initialize a List<T> to a given size (as opposed to capacity)?

Why are you using a List if you want to initialize it with a fixed value ? I can understand that -for the sake of performance- you want to give it an initial capacity, but isn't one of the advantages of a list over a regular array that it can grow when needed ?

When you do this:

List<int> = new List<int>(100);

You create a list whose capacity is 100 integers. This means that your List won't need to 'grow' until you add the 101th item. The underlying array of the list will be initialized with a length of 100.

Algorithm for Determining Tic Tac Toe Game Over

Another option: generate your table with code. Up to symmetry, there are only three ways to win: edge row, middle row, or diagonal. Take those three and spin them around every way possible:

def spin(g): return set([g, turn(g), turn(turn(g)), turn(turn(turn(g)))])
def turn(g): return tuple(tuple(g[y][x] for y in (0,1,2)) for x in (2,1,0))

X,s = 'X.'
XXX = X, X, X
sss = s, s, s

ways_to_win = (  spin((XXX, sss, sss))
               | spin((sss, XXX, sss))
               | spin(((X,s,s),
                       (s,X,s),
                       (s,s,X))))

These symmetries can have more uses in your game-playing code: if you get to a board you've already seen a rotated version of, you can just take the cached value or cached best move from that one (and unrotate it back). This is usually much faster than evaluating the game subtree.

(Flipping left and right can help the same way; it wasn't needed here because the set of rotations of the winning patterns is mirror-symmetric.)

Can I multiply strings in Java to repeat sequences?

If you're repeating single characters like the OP, and the maximum number of repeats is not too high, then you could use a simple substring operation like this:

int i = 3;
String someNum = "123";
someNum += "00000000000000000000".substring(0, i);

CodeIgniter Active Record - Get number of returned rows

Have a look at the result functions here:

$this->db->from('yourtable');
[... more active record code ...]
$query = $this->db->get();
$rowcount = $query->num_rows();

Scroll to a specific Element Using html

The above answers are good and correct. However, the code may not give the expected results. Allow me to add something to explain why this is very important.

It is true that adding the scroll-behavior: smooth to the html element allows smooth scrolling for the whole page. However not all web browsers support smooth scrolling using HTML.

So if you want to create a website accessible to all user, regardless of their web browsers, it is highly recommended to use JavaScript or a JavaScript library such as jQuery, to create a solution that will work for all browsers.

Otherwise, some users may not enjoy the smooth scrolling of your website / platform.

I can give a simpler example on how it can be applicable.

_x000D_
_x000D_ 
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<script>_x000D_
$(document).ready(function(){_x000D_
// Add smooth scrolling to all links_x000D_
$("a").on('click', function(event) {_x000D_
// Make sure this.hash has a value before overriding default behavior_x000D_
if (this.hash !== "") {_x000D_
// Prevent default anchor click behavior_x000D_
event.preventDefault();_x000D_
// Store hash_x000D_
var hash = this.hash;_x000D_
// Using jQuery's animate() method to add smooth page scroll_x000D_
// The optional number (800) specifies the number of milliseconds it takes to scroll to the specified area_x000D_
$('html, body').animate({_x000D_
scrollTop: $(hash).offset().top_x000D_
}, 800, function(){_x000D_
// Add hash (#) to URL when done scrolling (default click behavior)_x000D_
window.location.hash = hash;_x000D_
});_x000D_
} // End if_x000D_
});_x000D_
});_x000D_
</script>
_x000D_ 
<style>_x000D_
#section1 {_x000D_
height: 600px;_x000D_
background-color: pink;_x000D_
}_x000D_
#section2 {_x000D_
height: 600px;_x000D_
background-color: yellow;_x000D_
}_x000D_
</style>
_x000D_ 
<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
</head>_x000D_
<body>_x000D_
<h1>Smooth Scroll</h1>_x000D_
<div class="main" id="section1">_x000D_
<h2>Section 1</h2>_x000D_
<p>Click on the link to see the "smooth" scrolling effect.</p>_x000D_
<a href="#section2">Click Me to Smooth Scroll to Section 2 Below</a>_x000D_
<p>Note: Remove the scroll-behavior property to remove smooth scrolling.</p>_x000D_
</div>_x000D_
<div class="main" id="section2">_x000D_
<h2>Section 2</h2>_x000D_
<a href="#section1">Click Me to Smooth Scroll to Section 1 Above</a>_x000D_
</div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Interface vs Base class

It is explained well in this Java World article.

Personally, I tend to use interfaces to define interfaces - i.e. parts of the system design that specify how something should be accessed.

It's not uncommon that I will have a class implementing one or more interfaces.

Abstract classes I use as a basis for something else.

The following is an extract from the above mentioned article JavaWorld.com article, author Tony Sintes, 04/20/01

Interface vs. abstract class

Choosing interfaces and abstract classes is not an either/or proposition. If you need to change your design, make it an interface. However, you may have abstract classes that provide some default behavior. Abstract classes are excellent candidates inside of application frameworks.

Abstract classes let you define some behaviors; they force your subclasses to provide others. For example, if you have an application framework, an abstract class may provide default services such as event and message handling. Those services allow your application to plug in to your application framework. However, there is some application-specific functionality that only your application can perform. Such functionality might include startup and shutdown tasks, which are often application-dependent. So instead of trying to define that behavior itself, the abstract base class can declare abstract shutdown and startup methods. The base class knows that it needs those methods, but an abstract class lets your class admit that it doesn't know how to perform those actions; it only knows that it must initiate the actions. When it is time to start up, the abstract class can call the startup method. When the base class calls this method, Java calls the method defined by the child class.

Many developers forget that a class that defines an abstract method can call that method as well. Abstract classes are an excellent way to create planned inheritance hierarchies. They're also a good choice for nonleaf classes in class hierarchies.

Class vs. interface

Some say you should define all classes in terms of interfaces, but I think recommendation seems a bit extreme. I use interfaces when I see that something in my design will change frequently.

For example, the Strategy pattern lets you swap new algorithms and processes into your program without altering the objects that use them. A media player might know how to play CDs, MP3s, and wav files. Of course, you don't want to hardcode those playback algorithms into the player; that will make it difficult to add a new format like AVI. Furthermore, your code will be littered with useless case statements. And to add insult to injury, you will need to update those case statements each time you add a new algorithm. All in all, this is not a very object-oriented way to program.

With the Strategy pattern, you can simply encapsulate the algorithm behind an object. If you do that, you can provide new media plug-ins at any time. Let's call the plug-in class MediaStrategy. That object would have one method: playStream(Stream s). So to add a new algorithm, we simply extend our algorithm class. Now, when the program encounters the new media type, it simply delegates the playing of the stream to our media strategy. Of course, you'll need some plumbing to properly instantiate the algorithm strategies you will need.

This is an excellent place to use an interface. We've used the Strategy pattern, which clearly indicates a place in the design that will change. Thus, you should define the strategy as an interface. You should generally favor interfaces over inheritance when you want an object to have a certain type; in this case, MediaStrategy. Relying on inheritance for type identity is dangerous; it locks you into a particular inheritance hierarchy. Java doesn't allow multiple inheritance, so you can't extend something that gives you a useful implementation or more type identity.

What exactly does the Access-Control-Allow-Credentials header do?

By default, CORS does not include cookies on cross-origin requests. This is different from other cross-origin techniques such as JSON-P. JSON-P always includes cookies with the request, and this behavior can lead to a class of vulnerabilities called cross-site request forgery, or CSRF.

In order to reduce the chance of CSRF vulnerabilities in CORS, CORS requires both the server and the client to acknowledge that it is ok to include cookies on requests. Doing this makes cookies an active decision, rather than something that happens passively without any control.

The client code must set the withCredentials property on the XMLHttpRequest to true in order to give permission.

However, this header alone is not enough. The server must respond with the Access-Control-Allow-Credentials header. Responding with this header to true means that the server allows cookies (or other user credentials) to be included on cross-origin requests.

You also need to make sure your browser isn't blocking third-party cookies if you want cross-origin credentialed requests to work.

Note that regardless of whether you are making same-origin or cross-origin requests, you need to protect your site from CSRF (especially if your request includes cookies).

OpenSSL and error in reading openssl.conf file

 
set OPENSSL_CONF=c:/{path to openSSL}/bin/openssl.cfg

take care of the right extension (openssl.cfg not cnf)!

I have installed OpenSSL from here: http://slproweb.com/products/Win32OpenSSL.html

Tomcat 8 Maven Plugin for Java 8

Since November 2017, one can use tomcat8-maven-plugin:

<!-- https://mvnrepository.com/artifact/org.apache.tomcat.maven/tomcat8-maven-plugin -->
<dependency>
    <groupId>org.apache.tomcat.maven</groupId>
    <artifactId>tomcat8-maven-plugin</artifactId>
    <version>2.2</version>
</dependency>

Note that this plugin resides in ICM repo (not in Maven Central), hence you should add the repo to your pluginsRepositories in your pom.xml:

<pluginRepositories>
    <pluginRepository>
        <id>icm</id>
        <name>Spring Framework Milestone Repository</name>
        <url>http://maven.icm.edu.pl/artifactory/repo</url>
    </pluginRepository>
</pluginRepositories>

Storing an object in state of a React component?

this.setState({abc: {xyz: 'new value'}}); will NOT work, as state.abc will be entirely overwritten, not merged.

This works for me:

this.setState((previousState) => {
  previousState.abc.xyz = 'blurg';
  return previousState;
});

Unless I'm reading the docs wrong, Facebook recommends the above format. https://facebook.github.io/react/docs/component-api.html

Additionally, I guess the most direct way without mutating state is to directly copy by using the ES6 spread/rest operator:

const newState = { ...this.state.abc }; // deconstruct state.abc into a new object-- effectively making a copy
newState.xyz = 'blurg';
this.setState(newState);

Database development mistakes made by application developers

In my experience:
Not communicating with experienced DBAs.

How to debug "ImagePullBackOff"?

On GKE, if the pod is dead, it's best to check for the events. It will show in more detail what the error is about.

In my case, I had :

Failed to pull image "gcr.io/project/imagename@sha256:c8e91af54fc17faa1c49e2a05def5cbabf8f0a67fc558eb6cbca138061a8400a":
 rpc error: code = Unknown desc = error pulling image configuration: unknown blob

It turned out the image was damaged somehow. After repushing it and deploying with the new hash, it worked again.

How to debug PDO database queries?

I've created a modern Composer-loaded project / repository for exactly this here:

pdo-debug

Find the project's GitHub home here, see a blog post explaining it here. One line to add in your composer.json, and then you can use it like this:

echo debugPDO($sql, $parameters);

$sql is the raw SQL statement, $parameters is an array of your parameters: The key is the placeholder name (":user_id") or the number of the unnamed parameter ("?"), the value is .. well, the value.

The logic behind: This script will simply grad the parameters and replace them into the SQL string provided. Super-simple, but super-effective for 99% of your use-cases. Note: This is just a basic emulation, not a real PDO debugging (as this is not possible as PHP sends raw SQL and parameters to the MySQL server seperated).

A big thanks to bigwebguy and Mike from the StackOverflow thread Getting raw SQL query string from PDO for writing basically the entire main function behind this script. Big up!

Get first word of string

Split again by a whitespace:

var firstWords = [];
for (var i=0;i<codelines.length;i++)
{
  var words = codelines[i].split(" ");
  firstWords.push(words[0]);
}

Or use String.prototype.substr() (probably faster):

var firstWords = [];
for (var i=0;i<codelines.length;i++)
{
  var codeLine = codelines[i];
  var firstWord = codeLine.substr(0, codeLine.indexOf(" "));
  firstWords.push(firstWord);
}

'Static readonly' vs. 'const'

Constants are like the name implies, fields which don't change and are usually defined statically at compile time in the code.

Read-only variables are fields that can change under specific conditions.

They can be either initialized when you first declare them like a constant, but usually they are initialized during object construction inside the constructor.

They cannot be changed after the initialization takes place, in the conditions mentioned above.

Static read-only sounds like a poor choice to me since, if it's static and it never changes, so just use it public const. If it can change then it's not a constant and then, depending on your needs, you can either use read-only or just a regular variable.

Also, another important distinction is that a constant belongs to the class, while the read-only variable belongs to the instance!

Javascript "Uncaught TypeError: object is not a function" associativity question

Try to have the function body before the function call in your JavaScript file.

Git fast forward VS no fast forward merge

I can give an example commonly seen in project.

Here, option --no-ff (i.e. true merge) creates a new commit with multiple parents, and provides a better history tracking. Otherwise, --ff (i.e. fast-forward merge) is by default.

$ git checkout master
$ git checkout -b newFeature
$ ...
$ git commit -m 'work from day 1'
$ ...
$ git commit -m 'work from day 2'
$ ...
$ git commit -m 'finish the feature'
$ git checkout master
$ git merge --no-ff newFeature -m 'add new feature'
$ git log
// something like below
commit 'add new feature'         // => commit created at merge with proper message
commit 'finish the feature'
commit 'work from day 2'
commit 'work from day 1'
$ gitk                           // => see details with graph

$ git checkout -b anotherFeature        // => create a new branch (*)
$ ...
$ git commit -m 'work from day 3'
$ ...
$ git commit -m 'work from day 4'
$ ...
$ git commit -m 'finish another feature'
$ git checkout master
$ git merge anotherFeature       // --ff is by default, message will be ignored
$ git log
// something like below
commit 'work from day 4'
commit 'work from day 3'
commit 'add new feature'
commit 'finish the feature'
commit ...
$ gitk                           // => see details with graph

(*) Note that here if the newFeature branch is re-used, instead of creating a new branch, git will have to do a --no-ff merge anyway. This means fast forward merge is not always eligible.

How to get URL parameters with Javascript?

 
function getURLParameter(name) {
  return decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search) || [null, ''])[1].replace(/\+/g, '%20')) || null;
}

So you can use:

myvar = getURLParameter('myvar');

milliseconds to time in javascript

Prons:

  • simple and clean code; easy to modify for your needs
  • support any amount of hours (>24 hrs is ok)
  • format time as 00:00:00.0

You can put it into a helper file

export const msecToTime = ms => {
  const milliseconds = ms % 1000
  const seconds = Math.floor((ms / 1000) % 60)
  const minutes = Math.floor((ms / (60 * 1000)) % 60)
  const hours = Math.floor((ms / (3600 * 1000)) % 3600)
  return `${hours < 10 ? '0' + hours : hours}:${minutes < 10 ? '0' + minutes : minutes}:${
    seconds < 10 ? '0' + seconds : seconds
  }.${milliseconds}`
}

Reloading a ViewController

For UIViewController just load your view again -

func rightButtonAction() {
        if isEditProfile {
           print("Submit Clicked, Call Update profile API")
            isEditProfile = false
            self.viewWillAppear(true)
        } else {
            print("Edit Clicked, Call Edit profile API")
            isEditProfile = true
            self.viewWillAppear(true)
        }
    }

I am loading my view controller on profile edit and view profile. According to the Bool value isEditProfile updating the view in viewWillAppear method.

INSERT INTO ... SELECT FROM ... ON DUPLICATE KEY UPDATE

MySQL will assume the part before the equals references the columns named in the INSERT INTO clause, and the second part references the SELECT columns.

INSERT INTO lee(exp_id, created_by, location, animal, starttime, endtime, entct, 
                inact, inadur, inadist, 
                smlct, smldur, smldist, 
                larct, lardur, lardist, 
                emptyct, emptydur)
SELECT id, uid, t.location, t.animal, t.starttime, t.endtime, t.entct, 
       t.inact, t.inadur, t.inadist, 
       t.smlct, t.smldur, t.smldist, 
       t.larct, t.lardur, t.lardist, 
       t.emptyct, t.emptydur 
FROM tmp t WHERE uid=x
ON DUPLICATE KEY UPDATE entct=t.entct, inact=t.inact, ...

Unsupported major.minor version 52.0

It happens when you compile your projects on higher version of java(say jdk 1.8) and then run it on a lower version (say jdk 1.7).

If you have JRE-1.7 library in your project path then ,

1.Right click on project

2.Go to Properties

3.Select Project Facets

4.Find Java in rows and then choose version (say 1.7) if using JRE-1.7

5.Click Apply and run your project.

Matplotlib transparent line plots

After I plotted all the lines, I was able to set the transparency of all of them as follows:

for l in fig_field.gca().lines:
    l.set_alpha(.7)

EDIT: please see Joe's answer in the comments.

MySQL: Check if the user exists and drop it

In case you have a school server where the pupils worked a lot. You can just clean up the mess by:

delete from user where User != 'root' and User != 'admin';
delete from db where User != 'root' and User != 'admin';

delete from tables_priv;
delete from columns_priv;

flush privileges;

How to listen to the window scroll event in a VueJS component?

I know this is an old question, but I found a better solution with Vue.js 2.0+ Custom Directives: I needed to bind the scroll event too, then I implemented this.

First of, using @vue/cli, add the custom directive to src/main.js (before the Vue.js instance) or wherever you initiate it:

Vue.directive('scroll', {
  inserted: function(el, binding) {
    let f = function(evt) {
      if (binding.value(evt, el)) {
        window.removeEventListener('scroll', f);
      }
    }
    window.addEventListener('scroll', f);
  }
});

Then, add the custom v-scroll directive to the element and/or the component you want to bind on. Of course you have to insert a dedicated method: I used handleScroll in my example.

<my-component v-scroll="handleScroll"></my-component>

Last, add your method to the component.

methods: {
  handleScroll: function() {
    // your logic here
  }
}

You don’t have to care about the Vue.js lifecycle anymore here, because the custom directive itself does.

Creating and returning Observable from Angular 2 Service

This is an example from Angular2 docs of how you can create and use your own Observables :

The Service

import {Injectable} from 'angular2/core'
import {Subject}    from 'rxjs/Subject';
@Injectable()
export class MissionService {
  private _missionAnnouncedSource = new Subject<string>();
  missionAnnounced$ = this._missionAnnouncedSource.asObservable();

  announceMission(mission: string) {
    this._missionAnnouncedSource.next(mission)
  }
}

The Component

    import {Component}          from 'angular2/core';
    import {MissionService}     from './mission.service';

    export class MissionControlComponent {
      mission: string;

      constructor(private missionService: MissionService) {

        missionService.missionAnnounced$.subscribe(
          mission => {
            this.mission = mission;
          })
      }

      announce() {
        this.missionService.announceMission('some mission name');
      }
    }

Full and working example can be found here : https://angular.io/docs/ts/latest/cookbook/component-communication.html#!#bidirectional-service

How to check if an element is off-screen
  • Get the distance from the top of the given element
  • Add the height of the same given element. This will tell you the total number from the top of the screen to the end of the given element.

  • Then all you have to do is subtract that from total document height

    jQuery(function () {
    var documentHeight = jQuery(document).height();
    var element = jQuery('#you-element');
    var distanceFromBottom = documentHeight - (element.position().top + element.outerHeight(true));
    alert(distanceFromBottom)
});

Upload Progress Bar in PHP

This is by far (after hours of googling and trying scripts) the simplest to set up and nicest uploader I've found

https://github.com/FineUploader/fine-uploader

It doesn't require APC or any other external PHP libraries, I can get file progress feedback on a shared host, and it claims to support html5 drag and drop (personally untested) and multiple file uploads.

Quicker way to get all unique values of a column in VBA?

Try this

Option Explicit

Sub UniqueValues()
Dim ws As Worksheet
Dim uniqueRng As Range
Dim myCol As Long

myCol = 5 '<== set it as per your needs
Set ws = ThisWorkbook.Worksheets("unique") '<== set it as per your needs

Set uniqueRng = GetUniqueValues(ws, myCol)

End Sub


Function GetUniqueValues(ws As Worksheet, col As Long) As Range
Dim firstRow As Long

With ws
    .Columns(col).RemoveDuplicates Columns:=Array(1), header:=xlNo

    firstRow = 1
    If IsEmpty(.Cells(1, col)) Then firstRow = .Cells(1, col).End(xlDown).row

    Set GetUniqueValues = Range(.Cells(firstRow, col), .Cells(.Rows.Count, col).End(xlUp))
End With

End Function

it should be quite fast and without the drawback NeepNeepNeep told about

Extract a subset of a dataframe based on a condition involving a field

Just to extend the answer above you can also index your columns rather than specifying the column names which can also be useful depending on what you're doing. Given that your location is the first field it would look like this:

    bar <- foo[foo[ ,1] == "there", ]

This is useful because you can perform operations on your column value, like looping over specific columns (and you can do the same by indexing row numbers too).

This is also useful if you need to perform some operation on more than one column because you can then specify a range of columns:

    foo[foo[ ,c(1:N)], ]

Or specific columns, as you would expect.

    foo[foo[ ,c(1,5,9)], ]

Convert an array into an ArrayList

declaring the list (and initializing it with an empty arraylist)

List<Card> cardList = new ArrayList<Card>();

adding an element:

Card card;
cardList.add(card);

iterating over elements:

for(Card card : cardList){
    System.out.println(card);
}

How to develop a soft keyboard for Android?

Create Custom Key Board for Own EditText

Download Entire Code

In this post i Created Simple Keyboard which contains Some special keys like ( France keys ) and it's supported Capital letters and small letters and Number keys and some Symbols .

package sra.keyboard;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;

public class Main extends Activity implements OnTouchListener, OnClickListener,
  OnFocusChangeListener {
 private EditText mEt, mEt1; // Edit Text boxes
 private Button mBSpace, mBdone, mBack, mBChange, mNum;
 private RelativeLayout mLayout, mKLayout;
 private boolean isEdit = false, isEdit1 = false;
 private String mUpper = "upper", mLower = "lower";
 private int w, mWindowWidth;
 private String sL[] = { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
   "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w",
   "x", "y", "z", "ç", "à", "é", "è", "û", "î" };
 private String cL[] = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",
   "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W",
   "X", "Y", "Z", "ç", "à", "é", "è", "û", "î" };
 private String nS[] = { "!", ")", "'", "#", "3", "$", "%", "&", "8", "*",
   "?", "/", "+", "-", "9", "0", "1", "4", "@", "5", "7", "(", "2",
   "\"", "6", "_", "=", "]", "[", "<", ">", "|" };
 private Button mB[] = new Button[32];

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  try {
   setContentView(R.layout.main);
   // adjusting key regarding window sizes
   setKeys();
   setFrow();
   setSrow();
   setTrow();
   setForow();
   mEt = (EditText) findViewById(R.id.xEt);
   mEt.setOnTouchListener(this);
   mEt.setOnFocusChangeListener(this);
   mEt1 = (EditText) findViewById(R.id.et1);

   mEt1.setOnTouchListener(this);
   mEt1.setOnFocusChangeListener(this);
   mEt.setOnClickListener(this);
   mEt1.setOnClickListener(this);
   mLayout = (RelativeLayout) findViewById(R.id.xK1);
   mKLayout = (RelativeLayout) findViewById(R.id.xKeyBoard);

  } catch (Exception e) {
   Log.w(getClass().getName(), e.toString());
  }

 }

 @Override
 public boolean onTouch(View v, MotionEvent event) {
  if (v == mEt) {
   hideDefaultKeyboard();
   enableKeyboard();

  }
  if (v == mEt1) {
   hideDefaultKeyboard();
   enableKeyboard();

  }
  return true;
 }

 @Override
 public void onClick(View v) {

  if (v == mBChange) {

   if (mBChange.getTag().equals(mUpper)) {
    changeSmallLetters();
    changeSmallTags();
   } else if (mBChange.getTag().equals(mLower)) {
    changeCapitalLetters();
    changeCapitalTags();
   }

  } else if (v != mBdone && v != mBack && v != mBChange && v != mNum) {
   addText(v);

  } else if (v == mBdone) {

   disableKeyboard();

  } else if (v == mBack) {
   isBack(v);
  } else if (v == mNum) {
   String nTag = (String) mNum.getTag();
   if (nTag.equals("num")) {
    changeSyNuLetters();
    changeSyNuTags();
    mBChange.setVisibility(Button.INVISIBLE);

   }
   if (nTag.equals("ABC")) {
    changeCapitalLetters();
    changeCapitalTags();
   }

  }

 }

 @Override
 public void onFocusChange(View v, boolean hasFocus) {
  if (v == mEt && hasFocus == true) {
   isEdit = true;
   isEdit1 = false;

  } else if (v == mEt1 && hasFocus == true) {
   isEdit = false;
   isEdit1 = true;

  }

 }

 private void addText(View v) {
  if (isEdit == true) {
   String b = "";
   b = (String) v.getTag();
   if (b != null) {
    // adding text in Edittext
    mEt.append(b);

   }
  }

  if (isEdit1 == true) {
   String b = "";
   b = (String) v.getTag();
   if (b != null) {
    // adding text in Edittext
    mEt1.append(b);

   }

  }

 }

 private void isBack(View v) {
  if (isEdit == true) {
   CharSequence cc = mEt.getText();
   if (cc != null && cc.length() > 0) {
    {
     mEt.setText("");
     mEt.append(cc.subSequence(0, cc.length() - 1));
    }

   }
  }

  if (isEdit1 == true) {
   CharSequence cc = mEt1.getText();
   if (cc != null && cc.length() > 0) {
    {
     mEt1.setText("");
     mEt1.append(cc.subSequence(0, cc.length() - 1));
    }
   }
  }
 }
 private void changeSmallLetters() {
  mBChange.setVisibility(Button.VISIBLE);
  for (int i = 0; i < sL.length; i++)
   mB[i].setText(sL[i]);
  mNum.setTag("12#");
 }
 private void changeSmallTags() {
  for (int i = 0; i < sL.length; i++)
   mB[i].setTag(sL[i]);
  mBChange.setTag("lower");
  mNum.setTag("num");
 }
 private void changeCapitalLetters() {
  mBChange.setVisibility(Button.VISIBLE);
  for (int i = 0; i < cL.length; i++)
   mB[i].setText(cL[i]);
  mBChange.setTag("upper");
  mNum.setText("12#");

 }

 private void changeCapitalTags() {
  for (int i = 0; i < cL.length; i++)
   mB[i].setTag(cL[i]);
  mNum.setTag("num");

 }

 private void changeSyNuLetters() {

  for (int i = 0; i < nS.length; i++)
   mB[i].setText(nS[i]);
  mNum.setText("ABC");
 }

 private void changeSyNuTags() {
  for (int i = 0; i < nS.length; i++)
   mB[i].setTag(nS[i]);
  mNum.setTag("ABC");
 }

 // enabling customized keyboard
 private void enableKeyboard() {

  mLayout.setVisibility(RelativeLayout.VISIBLE);
  mKLayout.setVisibility(RelativeLayout.VISIBLE);

 }

 // Disable customized keyboard
 private void disableKeyboard() {
  mLayout.setVisibility(RelativeLayout.INVISIBLE);
  mKLayout.setVisibility(RelativeLayout.INVISIBLE);

 }

 private void hideDefaultKeyboard() {
  getWindow().setSoftInputMode(
    WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

 }

 private void setFrow() {
  w = (mWindowWidth / 13);
  w = w - 15;
  mB[16].setWidth(w);
  mB[22].setWidth(w + 3);
  mB[4].setWidth(w);
  mB[17].setWidth(w);
  mB[19].setWidth(w);
  mB[24].setWidth(w);
  mB[20].setWidth(w);
  mB[8].setWidth(w);
  mB[14].setWidth(w);
  mB[15].setWidth(w);
  mB[16].setHeight(50);
  mB[22].setHeight(50);
  mB[4].setHeight(50);
  mB[17].setHeight(50);
  mB[19].setHeight(50);
  mB[24].setHeight(50);
  mB[20].setHeight(50);
  mB[8].setHeight(50);
  mB[14].setHeight(50);
  mB[15].setHeight(50);

 }

 private void setSrow() {
  w = (mWindowWidth / 10);
  mB[0].setWidth(w);
  mB[18].setWidth(w);
  mB[3].setWidth(w);
  mB[5].setWidth(w);
  mB[6].setWidth(w);
  mB[7].setWidth(w);
  mB[26].setWidth(w);
  mB[9].setWidth(w);
  mB[10].setWidth(w);
  mB[11].setWidth(w);
  mB[26].setWidth(w);

  mB[0].setHeight(50);
  mB[18].setHeight(50);
  mB[3].setHeight(50);
  mB[5].setHeight(50);
  mB[6].setHeight(50);
  mB[7].setHeight(50);
  mB[9].setHeight(50);
  mB[10].setHeight(50);
  mB[11].setHeight(50);
  mB[26].setHeight(50);
 }

 private void setTrow() {
  w = (mWindowWidth / 12);
  mB[25].setWidth(w);
  mB[23].setWidth(w);
  mB[2].setWidth(w);
  mB[21].setWidth(w);
  mB[1].setWidth(w);
  mB[13].setWidth(w);
  mB[12].setWidth(w);
  mB[27].setWidth(w);
  mB[28].setWidth(w);
  mBack.setWidth(w);

  mB[25].setHeight(50);
  mB[23].setHeight(50);
  mB[2].setHeight(50);
  mB[21].setHeight(50);
  mB[1].setHeight(50);
  mB[13].setHeight(50);
  mB[12].setHeight(50);
  mB[27].setHeight(50);
  mB[28].setHeight(50);
  mBack.setHeight(50);

 }

 private void setForow() {
  w = (mWindowWidth / 10);
  mBSpace.setWidth(w * 4);
  mBSpace.setHeight(50);
  mB[29].setWidth(w);
  mB[29].setHeight(50);

  mB[30].setWidth(w);
  mB[30].setHeight(50);

  mB[31].setHeight(50);
  mB[31].setWidth(w);
  mBdone.setWidth(w + (w / 1));
  mBdone.setHeight(50);

 }

 private void setKeys() {
  mWindowWidth = getWindowManager().getDefaultDisplay().getWidth(); // getting
  // window
  // height
  // getting ids from xml files
  mB[0] = (Button) findViewById(R.id.xA);
  mB[1] = (Button) findViewById(R.id.xB);
  mB[2] = (Button) findViewById(R.id.xC);
  mB[3] = (Button) findViewById(R.id.xD);
  mB[4] = (Button) findViewById(R.id.xE);
  mB[5] = (Button) findViewById(R.id.xF);
  mB[6] = (Button) findViewById(R.id.xG);
  mB[7] = (Button) findViewById(R.id.xH);
  mB[8] = (Button) findViewById(R.id.xI);
  mB[9] = (Button) findViewById(R.id.xJ);
  mB[10] = (Button) findViewById(R.id.xK);
  mB[11] = (Button) findViewById(R.id.xL);
  mB[12] = (Button) findViewById(R.id.xM);
  mB[13] = (Button) findViewById(R.id.xN);
  mB[14] = (Button) findViewById(R.id.xO);
  mB[15] = (Button) findViewById(R.id.xP);
  mB[16] = (Button) findViewById(R.id.xQ);
  mB[17] = (Button) findViewById(R.id.xR);
  mB[18] = (Button) findViewById(R.id.xS);
  mB[19] = (Button) findViewById(R.id.xT);
  mB[20] = (Button) findViewById(R.id.xU);
  mB[21] = (Button) findViewById(R.id.xV);
  mB[22] = (Button) findViewById(R.id.xW);
  mB[23] = (Button) findViewById(R.id.xX);
  mB[24] = (Button) findViewById(R.id.xY);
  mB[25] = (Button) findViewById(R.id.xZ);
  mB[26] = (Button) findViewById(R.id.xS1);
  mB[27] = (Button) findViewById(R.id.xS2);
  mB[28] = (Button) findViewById(R.id.xS3);
  mB[29] = (Button) findViewById(R.id.xS4);
  mB[30] = (Button) findViewById(R.id.xS5);
  mB[31] = (Button) findViewById(R.id.xS6);
  mBSpace = (Button) findViewById(R.id.xSpace);
  mBdone = (Button) findViewById(R.id.xDone);
  mBChange = (Button) findViewById(R.id.xChange);
  mBack = (Button) findViewById(R.id.xBack);
  mNum = (Button) findViewById(R.id.xNum);
  for (int i = 0; i < mB.length; i++)
   mB[i].setOnClickListener(this);
  mBSpace.setOnClickListener(this);
  mBdone.setOnClickListener(this);
  mBack.setOnClickListener(this);
  mBChange.setOnClickListener(this);
  mNum.setOnClickListener(this);

 }

}

How do I deal with special characters like \^$.?*|+()[{ in my regex?

Escape with a double backslash

R treats backslashes as escape values for character constants. (... and so do regular expressions. Hence the need for two backslashes when supplying a character argument for a pattern. The first one isn't actually a character, but rather it makes the second one into a character.) You can see how they are processed using cat.

y <- "double quote: \", tab: \t, newline: \n, unicode point: \u20AC"
print(y)
## [1] "double quote: \", tab: \t, newline: \n, unicode point: €"
cat(y)
## double quote: ", tab:    , newline: 
## , unicode point: €

Further reading: Escaping a backslash with a backslash in R produces 2 backslashes in a string, not 1

To use special characters in a regular expression the simplest method is usually to escape them with a backslash, but as noted above, the backslash itself needs to be escaped.

grepl("\\[", "a[b")
## [1] TRUE

To match backslashes, you need to double escape, resulting in four backslashes.

grepl("\\\\", c("a\\b", "a\nb"))
## [1]  TRUE FALSE

The rebus package contains constants for each of the special characters to save you mistyping slashes.

library(rebus)
OPEN_BRACKET
## [1] "\\["
BACKSLASH
## [1] "\\\\"

For more examples see:

?SpecialCharacters

Your problem can be solved this way:

library(rebus)
grepl(OPEN_BRACKET, "a[b")

Form a character class

You can also wrap the special characters in square brackets to form a character class.

grepl("[?]", "a?b")
## [1] TRUE

Two of the special characters have special meaning inside character classes: \ and ^.

Backslash still needs to be escaped even if it is inside a character class.

grepl("[\\\\]", c("a\\b", "a\nb"))
## [1]  TRUE FALSE

Caret only needs to be escaped if it is directly after the opening square bracket.

grepl("[ ^]", "a^b")  # matches spaces as well.
## [1] TRUE
grepl("[\\^]", "a^b") 
## [1] TRUE

rebus also lets you form a character class.

char_class("?")
## <regex> [?]

Use a pre-existing character class

If you want to match all punctuation, you can use the [:punct:] character class.

grepl("[[:punct:]]", c("//", "[", "(", "{", "?", "^", "$"))
## [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE

stringi maps this to the Unicode General Category for punctuation, so its behaviour is slightly different.

stri_detect_regex(c("//", "[", "(", "{", "?", "^", "$"), "[[:punct:]]")
## [1]  TRUE  TRUE  TRUE  TRUE  TRUE FALSE FALSE

You can also use the cross-platform syntax for accessing a UGC.

stri_detect_regex(c("//", "[", "(", "{", "?", "^", "$"), "\\p{P}")
## [1]  TRUE  TRUE  TRUE  TRUE  TRUE FALSE FALSE

Use \Q \E escapes

Placing characters between \\Q and \\E makes the regular expression engine treat them literally rather than as regular expressions.

grepl("\\Q.\\E", "a.b")
## [1] TRUE

rebus lets you write literal blocks of regular expressions.

literal(".")
## <regex> \Q.\E

Don't use regular expressions

Regular expressions are not always the answer. If you want to match a fixed string then you can do, for example:

grepl("[", "a[b", fixed = TRUE)
stringr::str_detect("a[b", fixed("["))
stringi::stri_detect_fixed("a[b", "[")

Count distinct values

Ok, I deleted my previous answer because finally it was not what willlangford was looking for, but I made my point that maybe we were all misunderstanding the question.

I also thought of the SELECT DISTINCT... thing at first, but it seemed too weird to me that someone needed to know how many people had a different number of pets than the rest... thats why I thought that maybe the question was not clear enough.

So, now that the real question meaning is clarified, making a subquery for this its quite an overhead, I would preferably use a GROUP BY clause.

Imagine you have the table customer_pets like this:

+-----------------------+
|  customer  |   pets   |
+------------+----------+
| customer1  |    2     |
| customer2  |    3     |
| customer3  |    2     |
| customer4  |    2     |
| customer5  |    3     |
| customer6  |    4     |
+------------+----------+

then

SELECT count(customer) AS num_customers, pets FROM customer_pets GROUP BY pets

would return:

+----------------------------+
|  num_customers  |   pets   |
+-----------------+----------+
|        3        |    2     |
|        2        |    3     |
|        1        |    4     |
+-----------------+----------+

as you need.

Corrupt jar file

It can be a typo int the MANIFEST.MF too, p.ex. Build-Date with two :

  Build-Date:: 2017-03-13 16:07:12

Installing RubyGems in Windows

To setup you Ruby development environment on Windows:

  1. Install Ruby via RubyInstaller: http://rubyinstaller.org/downloads/

  2. Check your ruby version: Start - Run - type in cmd to open a windows console

  3. Type in ruby -v
  4. You will get something like that: ruby 2.0.0p353 (2013-11-22) [i386-mingw32]

For Ruby 2.4 or later, run the extra installation at the end to install the DevelopmentKit. If you forgot to do that, run ridk install in your windows console to install it.

For earlier versions:

  1. Download and install DevelopmentKit from the same download page as Ruby Installer. Choose an ?exe file corresponding to your environment (32 bits or 64 bits and working with your version of Ruby).
  2. Follow the installation instructions for DevelopmentKit described at: https://github.com/oneclick/rubyinstaller/wiki/Development-Kit#installation-instructions. Adapt it for Windows.
  3. After installing DevelopmentKit you can install all needed gems by just running from the command prompt (windows console or terminal): gem install {gem name}. For example, to install rails, just run gem install rails.

Hope this helps.

presenting ViewController with NavigationViewController swift

My navigation bar was not showing, so I have used the following method in Swift 2 iOS 9

let viewController = self.storyboard?.instantiateViewControllerWithIdentifier("Dashboard") as! Dashboard

// Creating a navigation controller with viewController at the root of the navigation stack.
let navController = UINavigationController(rootViewController: viewController)
self.presentViewController(navController, animated:true, completion: nil)

Maximum number of rows in an MS Access database engine table?

When working with 4 large Db2 tables I have not only found the limit but it caused me to look really bad to a boss who thought that I could append all four tables (each with over 900,000 rows) to one large table. the real life result was that regardless of how many times I tried the Table (which had exactly 34 columns - 30 text and 3 integer) would spit out some cryptic message "Cannot open database unrecognized format or the file may be corrupted". Bottom Line is Less than 1,500,000 records and just a bit more than 1,252,000 with 34 rows.

Prevent PDF file from downloading and printing

Okay, I take back what I commented earlier. Just talked to one of the senior guys in my shop and he said it is possible to lock it down hard. What you can do is convert the pdf to an image/flash/whatever and wrap it in an iFrame. Then, you create another image with 100% transparency and lay it over top the iFrame (not in it) and set it to have a higher Z-value than the iFrame.

What this will do is that if they right click on the 'image' to save it, they will be saving the transparent image instead. And since the image 'overrides' the iFrame, any attempt to use print screen should be shielded by the image, and they should only be able to snapshot the image that doesn't actually exist.

That leaves only one or two ways to get at the file...which requires digging straight into the source code to find the image file inside the iFrame. Still not totally secure, but protected from your average user.

Determining the size of an Android view at runtime

Here is the code for getting the layout via overriding a view if API < 11 (API 11 includes the View.OnLayoutChangedListener feature):

public class CustomListView extends ListView
{
    private OnLayoutChangedListener layoutChangedListener;

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

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b)
    {
        if (layoutChangedListener != null)
        {
            layoutChangedListener.onLayout(changed, l, t, r, b);
        }
        super.onLayout(changed, l, t, r, b);
    }

    public void setLayoutChangedListener(
        OnLayoutChangedListener layoutChangedListener)
    {
        this.layoutChangedListener = layoutChangedListener;
    }
}
public interface OnLayoutChangedListener
{
    void onLayout(boolean changed, int l, int t, int r, int b);
}

Get Selected Item Using Checkbox in Listview

It's a simplifications but very easy... You need to add the the focusable flag to the checkbox, as written before. You need also to add the clickable flag, as shown here:

android:focusable="false"
android:clickable="false"

Than you control the checkbox state from within the ListView (ListFragment in my case) onListItemClick event.

This the sample onListItemClick method:

public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
//Get related checkbox and change flag status..
CheckBox cb = (CheckBox)v.findViewById(R.id.rowDone);
cb.setChecked(!cb.isChecked());
Toast.makeText(getActivity(), "Click item", Toast.LENGTH_SHORT).show();
}

C# - How to convert string to char?

A string can be converted to an array of characters by calling the ToCharArray string's method.

var characters = stringValue.ToCharArray();

An object of type string[] is not a string, but an array of strings. You cannot convert an array of strings to an array of characters by just calling a method like ToCharArray. To be more correct there isn't any method in the .NET framework that does this thing. You could however declare an extension method to do this, but this is another discussion.

If your intention is to build an array of the characters that make up the strings you have in your array, you could do so by calling the ToCharArray method on each string of your array.

HTML5 Canvas: Zooming

One option is to use css zoom feature: 

$("#canvas_id").css("zoom","x%");

Decompile an APK, modify it and then recompile it

I know this question is answered still, I would like to pass an information how to get source code from apk with out dexjar.

There is an online decompiler for android apks

  1. Upload apk from local machine
  2. Wait some moments
  3. Download source code in zip format

I don't know how reliable is this.

@darkheir Answer is the manual way to do decompile apk. It helps us to understand different phases in Apk creation.

Once you have source code , follow the step mentioned in the accepted answer

Report so many ads on this links Another online Apk De-compiler @Andrew Rukin : http://www.javadecompilers.com/apk

Still worth. Hats Off to creators.

How to exit a function in bash

If you want to return from an outer function with an error without exiting you can use this trick:

do-something-complex() {
  # Using `return` here would only return from `fail`, not from `do-something-complex`.
  # Using `exit` would close the entire shell.
  # So we (ab)use a different feature. :)
  fail() { : "${__fail_fast:?$1}"; }

  nested-func() {
      try-this || fail "This didn't work"
      try-that || fail "That didn't work"
  }
  nested-func
}

Trying it out:

$ do-something-complex
try-this: command not found
bash: __fail_fast: This didn't work

This has the added benefit/drawback that you can optionally turn off this feature: __fail_fast=x do-something-complex.

Note that this causes the outermost function to return 1.

How to check the differences between local and github before the pull

And another useful command to do this (after git fetch) is:

git log origin/master ^master

This shows the commits that are in origin/master but not in master. You can also do it in opposite when doing git pull, to check what commits will be submitted to remote.

How to speed up insertion performance in PostgreSQL

See populate a database in the PostgreSQL manual, depesz's excellent-as-usual article on the topic, and this SO question.

(Note that this answer is about bulk-loading data into an existing DB or to create a new one. If you're interested DB restore performance with pg_restore or psql execution of pg_dump output, much of this doesn't apply since pg_dump and pg_restore already do things like creating triggers and indexes after it finishes a schema+data restore).

There's lots to be done. The ideal solution would be to import into an UNLOGGED table without indexes, then change it to logged and add the indexes. Unfortunately in PostgreSQL 9.4 there's no support for changing tables from UNLOGGED to logged. 9.5 adds ALTER TABLE ... SET LOGGED to permit you to do this.

If you can take your database offline for the bulk import, use pg_bulkload.

Otherwise:

  • Disable any triggers on the table

  • Drop indexes before starting the import, re-create them afterwards. (It takes much less time to build an index in one pass than it does to add the same data to it progressively, and the resulting index is much more compact).

  • If doing the import within a single transaction, it's safe to drop foreign key constraints, do the import, and re-create the constraints before committing. Do not do this if the import is split across multiple transactions as you might introduce invalid data.

  • If possible, use COPY instead of INSERTs

  • If you can't use COPY consider using multi-valued INSERTs if practical. You seem to be doing this already. Don't try to list too many values in a single VALUES though; those values have to fit in memory a couple of times over, so keep it to a few hundred per statement.

  • Batch your inserts into explicit transactions, doing hundreds of thousands or millions of inserts per transaction. There's no practical limit AFAIK, but batching will let you recover from an error by marking the start of each batch in your input data. Again, you seem to be doing this already.

  • Use synchronous_commit=off and a huge commit_delay to reduce fsync() costs. This won't help much if you've batched your work into big transactions, though.

  • INSERT or COPY in parallel from several connections. How many depends on your hardware's disk subsystem; as a rule of thumb, you want one connection per physical hard drive if using direct attached storage.

  • Set a high checkpoint_segments value and enable log_checkpoints. Look at the PostgreSQL logs and make sure it's not complaining about checkpoints occurring too frequently.

  • If and only if you don't mind losing your entire PostgreSQL cluster (your database and any others on the same cluster) to catastrophic corruption if the system crashes during the import, you can stop Pg, set fsync=off, start Pg, do your import, then (vitally) stop Pg and set fsync=on again. See WAL configuration. Do not do this if there is already any data you care about in any database on your PostgreSQL install. If you set fsync=off you can also set full_page_writes=off; again, just remember to turn it back on after your import to prevent database corruption and data loss. See non-durable settings in the Pg manual.

You should also look at tuning your system:

  • Use good quality SSDs for storage as much as possible. Good SSDs with reliable, power-protected write-back caches make commit rates incredibly faster. They're less beneficial when you follow the advice above - which reduces disk flushes / number of fsync()s - but can still be a big help. Do not use cheap SSDs without proper power-failure protection unless you don't care about keeping your data.

  • If you're using RAID 5 or RAID 6 for direct attached storage, stop now. Back your data up, restructure your RAID array to RAID 10, and try again. RAID 5/6 are hopeless for bulk write performance - though a good RAID controller with a big cache can help.

  • If you have the option of using a hardware RAID controller with a big battery-backed write-back cache this can really improve write performance for workloads with lots of commits. It doesn't help as much if you're using async commit with a commit_delay or if you're doing fewer big transactions during bulk loading.

  • If possible, store WAL (pg_xlog) on a separate disk / disk array. There's little point in using a separate filesystem on the same disk. People often choose to use a RAID1 pair for WAL. Again, this has more effect on systems with high commit rates, and it has little effect if you're using an unlogged table as the data load target.

You may also be interested in Optimise PostgreSQL for fast testing.

Where can I find the error logs of nginx, using FastCGI and Django?

My ngninx logs are located here:

/usr/local/var/log/nginx/*

You can also check your nginx.conf to see if you have any directives dumping to custom log.

run nginx -t to locate your nginx.conf. 

# in ngingx.conf
error_log  /usr/local/var/log/nginx/error.log;
error_log  /usr/local/var/log/nginx/error.log  notice;
error_log  /usr/local/var/log/nginx/error.log  info;

Nginx is usually set up in /usr/local or /etc/. The server could be configured to dump logs to /var/log as well.

If you have an alternate location for your nginx install and all else fails, you could use the find command to locate your file of choice.

find /usr/ -path "*/nginx/*" -type f -name '*.log', where /usr/ is the folder you wish to start searching from.

Initializing a struct to 0

See §6.7.9 Initialization:

21 If there are fewer initializers in a brace-enclosed list than there are elements or members of an aggregate, or fewer characters in a string literal used to initialize an array of known size than there are elements in the array, the remainder of the aggregate shall be initialized implicitly the same as objects that have static storage duration.

So, yes both of them work. Note that in C99 a new way of initialization, called designated initialization can be used too:

myStruct _m1 = {.c2 = 0, .c1 = 1};

Get height of div with no height set in css

Can do this in jQuery. Try all options .height(), .innerHeight() or .outerHeight().

$('document').ready(function() {
    $('#right_div').css({'height': $('#left_div').innerHeight()});
});

Example Screenshot

enter image description here

Hope this helps. Thanks!!

Twitter Bootstrap tabs not working: when I click on them nothing happens

Actually, there is another easy way to do it. It works for me but I'm not sure for you guys. The key thing here, is just adding the FADE in each (tab-pane) and it will works. Besides, you don't even need to script function or whatever version of jQuery. Here is my code...hope it will works for you all.

<div class="tab-pane fade" id="Customer">
    <table class="table table-hover table-bordered">
        <tr>
            <th width="40%">Contact Person</th>
            <td><?php echo $event['Event']['e_contact_person']; ?></td>
        </tr>
    </table>
</div>
<div class="tab-pane fade" id="Delivery">
    <table class="table table-hover table-bordered">
        <tr>
            <th width="40%">Time Arrive Warehouse Start</th>
            <td><?php echo $event['Event']['e_time_arrive_WH_start']; ?></td>
        </tr>
    </table>
</div>

IntelliJ IDEA JDK configuration on Mac OS

The JDK path might change when you update JAVA. For Mac you should go to the following path to check the JAVA version installed. 

/Library/Java/JavaVirtualMachines/

Next, say JDK version that you find is jdk1.8.0_151.jdk, the path to home directory within it is the JDK home path.

In my case it was : 

/Library/Java/JavaVirtualMachines/jdk1.8.0_151.jdk/Contents/Home

You can configure it by going to File -> Project Structure -> SDKs.

enter image description here enter image description here

What is the best comment in source code you have ever encountered?

 
// human madable inconvenient. Way too sucks.

I still don't fully understand what it means, but I have found it to be very true about a lot of code.

How to add a delay for a 2 or 3 seconds

 
System.Threading.Thread.Sleep(
    (int)System.TimeSpan.FromSeconds(3).TotalMilliseconds);

Or with using statements:

Thread.Sleep((int)TimeSpan.FromSeconds(2).TotalMilliseconds);

I prefer this to 1000 * numSeconds (or simply 3000) because it makes it more obvious what is going on to someone who hasn't used Thread.Sleep before. It better documents your intent.

What is the correct way to check for string equality in JavaScript?

Just one addition to answers: If all these methods return false, even if strings seem to be equal, it is possible that there is a whitespace to the left and or right of one string. So, just put a .trim() at the end of strings before comparing:

if(s1.trim() === s2.trim())
{
    // your code
}

I have lost hours trying to figure out what is wrong. Hope this will help to someone!

Read file line by line in PowerShell

Get-Content has bad performance; it tries to read the file into memory all at once.

C# (.NET) file reader reads each line one by one

Best Performace

foreach($line in [System.IO.File]::ReadLines("C:\path\to\file.txt"))
{
       $line
}

Or slightly less performant

[System.IO.File]::ReadLines("C:\path\to\file.txt") | ForEach-Object {
       $_
}

The foreach statement will likely be slightly faster than ForEach-Object (see comments below for more information).

How long will my session last?

If session.cookie_lifetime is 0, the session cookie lives until the browser is quit.

EDIT: Others have mentioned the session.gc_maxlifetime setting. When session garbage collection occurs, the garbage collector will delete any session data that has not been accessed in longer than session.gc_maxlifetime seconds. To set the time-to-live for the session cookie, call session_set_cookie_params() or define the session.cookie_lifetime PHP setting. If this setting is greater than session.gc_maxlifetime, you should increase session.gc_maxlifetime to a value greater than or equal to the cookie lifetime to ensure that your sessions won't expire.

Hash string in c#

 
using System.Security.Cryptography;

public static byte[] GetHash(string inputString)
{
    using (HashAlgorithm algorithm = SHA256.Create())
        return algorithm.ComputeHash(Encoding.UTF8.GetBytes(inputString));
}

public static string GetHashString(string inputString)
{
    StringBuilder sb = new StringBuilder();
    foreach (byte b in GetHash(inputString))
        sb.Append(b.ToString("X2"));

    return sb.ToString();
}

Additional Notes

  • Since MD5 and SHA1 are obsolete and insecure algorithms, this solution uses SHA256. Alternatively, you can use BCrypt or Scrypt as pointed out in comments.
  • Also, consider "salting" your hashes and use proven cryptographic algorithms, as pointed out in comments.

How to convert SQL Query result to PANDAS Data Structure?

best way I do this

db.execute(query) where db=db_class() #database class
    mydata=[x for x in db.fetchall()]
    df=pd.DataFrame(data=mydata)

SCRIPT7002: XMLHttpRequest: Network Error 0x2ef3, Could not complete the operation due to error 00002ef3

Have encountered the same issue in my asp.net project, in the end i found the issue is with the target function not static, the issue fixed after I put the keyword static.

[WebMethod]
public static List<string> getRawData()

Array to Collection: Optimized code

Yes, there is. You can use the Arrays class from the java.util.* package. Then it's actually just one line of code.

List<String> list = Arrays.asList(array);

addEventListener in Internet Explorer

I'm using this solution and works in IE8 or greater.

if (typeof Element.prototype.addEventListener === 'undefined') {
    Element.prototype.addEventListener = function (e, callback) {
      e = 'on' + e;
      return this.attachEvent(e, callback);
    };
  }

And then:

<button class="click-me">Say Hello</button>

<script>
  document.querySelectorAll('.click-me')[0].addEventListener('click', function () {
    console.log('Hello');
  });
</script>

This will work both IE8 and Chrome, Firefox, etc.

Making a mocked method return an argument that was passed to it

With Java 8, Steve's answer can become 

public void testMyFunction() throws Exception {
    Application mock = mock(Application.class);
    when(mock.myFunction(anyString())).thenAnswer(
    invocation -> {
        Object[] args = invocation.getArguments();
        return args[0];
    });

    assertEquals("someString", mock.myFunction("someString"));
    assertEquals("anotherString", mock.myFunction("anotherString"));
}

EDIT: Even shorter: 

public void testMyFunction() throws Exception {
    Application mock = mock(Application.class);
    when(mock.myFunction(anyString())).thenAnswer(
        invocation -> invocation.getArgument(0));

    assertEquals("someString", mock.myFunction("someString"));
    assertEquals("anotherString", mock.myFunction("anotherString"));
}

What is a "method" in Python?

In Python, a method is a function that is available for a given object because of the object's type.

For example, if you create my_list = [1, 2, 3], the append method can be applied to my_list because it's a Python list: my_list.append(4). All lists have an append method simply because they are lists.

As another example, if you create my_string = 'some lowercase text', the upper method can be applied to my_string simply because it's a Python string: my_string.upper().

Lists don't have an upper method, and strings don't have an append method. Why? Because methods only exist for a particular object if they have been explicitly defined for that type of object, and Python's developers have (so far) decided that those particular methods are not needed for those particular objects.

To call a method, the format is object_name.method_name(), and any arguments to the method are listed within the parentheses. The method implicitly acts on the object being named, and thus some methods don't have any stated arguments since the object itself is the only necessary argument. For example, my_string.upper() doesn't have any listed arguments because the only required argument is the object itself, my_string.

One common point of confusion regards the following:

import math
math.sqrt(81)

Is sqrt a method of the math object? No. This is how you call the sqrt function from the math module. The format being used is module_name.function_name(), instead of object_name.method_name(). In general, the only way to distinguish between the two formats (visually) is to look in the rest of the code and see if the part before the period (math, my_list, my_string) is defined as an object or a module.

How do I delete multiple rows with different IDs?

Disclaim: the following suggestion could be an overhead depending on the situation. The function is only tested with MSSQL 2008 R2 but seams be compatible to other versions

if you wane do this with many Id's you may could use a function which creates a temp table where you will be able to DELETE FROM the selection

how the query could look like:

-- not tested
-- @ids will contain a varchar with your ids e.g.'9 12 27 37'
DELETE FROM table WHERE id IN (SELECT i.number FROM iter_intlist_to_tbl(@ids))

here is the function:

ALTER FUNCTION iter_intlist_to_tbl (@list nvarchar(MAX))
   RETURNS @tbl TABLE (listpos int IDENTITY(1, 1) NOT NULL,
                       number  int NOT NULL) AS

   -- funktion gefunden auf http://www.sommarskog.se/arrays-in-sql-2005.html
   -- dient zum übergeben einer liste von elementen

BEGIN
    -- Deklaration der Variablen
    DECLARE @startpos int,
            @endpos   int,
            @textpos  int,
            @chunklen smallint,
            @str      nvarchar(4000),
            @tmpstr   nvarchar(4000),
            @leftover nvarchar(4000)

    -- Startwerte festlegen
   SET @textpos = 1
   SET @leftover = ''

   -- Loop 1
    WHILE @textpos <= datalength(@list) / 2
    BEGIN

        --
        SET @chunklen = 4000 - datalength(@leftover) / 2 --datalength() gibt die anzahl der bytes zurück (mit Leerzeichen)

        --
        SET @tmpstr = ltrim(@leftover + substring(@list, @textpos, @chunklen))--SUBSTRING ( @string ,start , length ) | ltrim(@string) abschneiden aller Leerzeichen am Begin des Strings

        --hochzählen der TestPosition
        SET @textpos = @textpos + @chunklen

        --start position 0 setzen
        SET @startpos = 0

        -- end position bekommt den charindex wo ein [LEERZEICHEN] gefunden wird
        SET @endpos = charindex(' ' COLLATE Slovenian_BIN2, @tmpstr)--charindex(searchChar,Wo,Startposition)

        -- Loop 2
        WHILE @endpos > 0
        BEGIN
            --str ist der string welcher zwischen den [LEERZEICHEN] steht
            SET @str = substring(@tmpstr, @startpos + 1, @endpos - @startpos - 1) 

            --wenn @str nicht leer ist wird er zu int Convertiert und @tbl unter der Spalte 'number' hinzugefügt
            IF @str <> ''
                INSERT @tbl (number) VALUES(convert(int, @str))-- convert(Ziel-Type,Value)

            -- start wird auf das letzte bekannte end gesetzt
            SET @startpos = @endpos

            -- end position bekommt den charindex wo ein [LEERZEICHEN] gefunden wird
            SET @endpos = charindex(' ' COLLATE Slovenian_BIN2, @tmpstr, @startpos + 1)
        END
        -- Loop 2

        -- dient dafür den letzten teil des strings zu selektieren
        SET @leftover = right(@tmpstr, datalength(@tmpstr) / 2 - @startpos)--right(@string,anzahl der Zeichen) bsp.: right("abcdef",3) => "def"
    END
    -- Loop 1

    --wenn @leftover nach dem entfernen aller [LEERZEICHEN] nicht leer ist wird er zu int Convertiert und @tbl unter der Spalte 'number' hinzugefügt
    IF ltrim(rtrim(@leftover)) <> ''
        INSERT @tbl (number) VALUES(convert(int, @leftover))

    RETURN
END


    -- ############################ WICHTIG ############################
    -- das is ein Beispiel wie man die Funktion benutzt
    --
    --CREATE    PROCEDURE get_product_names_iter 
    --      @ids varchar(50) AS
    --SELECT    P.ProductName, P.ProductID
    --FROM      Northwind.Products P
    --JOIN      iter_intlist_to_tbl(@ids) i ON P.ProductID = i.number
    --go
    --EXEC get_product_names_iter '9 12 27 37'
    --
    -- Funktion gefunden auf http://www.sommarskog.se/arrays-in-sql-2005.html
    -- dient zum übergeben einer Liste von Id's
    -- ############################ WICHTIG ############################

initializing a boolean array in java

public static Boolean freq[] = new Boolean[Global.iParameter[2]];

Global.iParameter[2]:

It should be const value

Microsoft SQL Server 2005 service fails to start

We had a similar problem recently withour running SQL 2005 servers (more specifically: The reporting services). The windows services didn't start anymore with no real error message whatsoever.

I found out that this problem was related to some KB hotfixes that have been deployed lately. For some reason those hotfixes resulted in the services taking longer than usually for starting up.

Since by default, there is a timeout that kills the service after 30 seconds when it was not able to go beyond the start methods, this was the reason why it simply terminated.

Maybe this is what you are experiencing.

Theres a work around described on Microsoft Connect (link). Although the hotfixes listed in this article didn't match the ones that have been deployed to our systems, the workaround worked for us.

Convert comma separated string to array in PL/SQL

You can use Replace Function to replace comma easily. To Do this-

The syntax for the REPLACE function in SQL Server (Transact-SQL) is:
REPLACE( string, string_to_replace, replacement_string )

Parameters or Arguments

string : The source string from which a sequence of characters will be replaced by another set of characters.
string_to_replace : The string that will be searched for in string1.
replacement_string : The replacement string. All occurrences of string_to_replace will be replaced with replacement_string in string1.
Note :

The REPLACE function performs a replacement that is not case-sensitive. So all occurrences of string_to_replace will be replaced with replacement_string regardless of the case of string_to_replace or replacement_string

For Example :
SELECT REPLACE('Kapil,raj,chouhan', ',' , ' ') from DUAL;
Result : Kapil raj chouhan

SELECT REPLACE('I Live In India', ' ' , '-') from DUAL;
Result : I-Live-In-India

SELECT REPLACE('facebook.com', 'face' , 'friends') from DUAL;
Result : friendsbook.com

I Hope it will be usefull for you.

How to read value of a registry key c#

Change:

using (RegistryKey key = Registry.LocalMachine.OpenSubKey("Software\\Wow6432Node\\MySQL AB\\MySQL Connector\\Net"))

To:

 using (RegistryKey key = Registry.LocalMachine.OpenSubKey("Software\Wow6432Node\MySQL AB\MySQL Connector\Net"))

Understanding colors on Android (six characters)

Android Material Design

These are the conversions for setting the text color opacity levels.

  • 100%: FF
  • 87%: DE
  • 70%: B3
  • 54%: 8A
  • 50%: 80
  • 38%: 61
  • 12%: 1F

Dark text on light backgrounds

enter image description here

  • Primary text: DE000000
  • Secondary text: 8A000000
  • Disabled text, hint text, and icons: 61000000
  • Dividers: 1F000000

White text on dark backgrounds

enter image description here

  • Primary text: FFFFFFFF
  • Secondary text: B3FFFFFF
  • Disabled text, hint text, and icons: 80FFFFFF
  • Dividers: 1FFFFFFF

See also

  • Look up any percentage here.

How to select the comparison of two columns as one column in Oracle

I stopped using DECODE several years ago because it is non-portable. Also, it is less flexible and less readable than a CASE/WHEN.

However, there is one neat "trick" you can do with decode because of how it deals with NULL. In decode, NULL is equal to NULL. That can be exploited to tell whether two columns are different as below.

select a, b, decode(a, b, 'true', 'false') as same
  from t;

     A       B  SAME
------  ------  -----
     1       1  true
     1       0  false
     1          false
  null    null  true

How to insert a blob into a database using sql server management studio

You can insert into a varbinary(max) field using T-SQL within SQL Server Management Studio and in particular using the OPENROWSET commmand.

For example:

INSERT Production.ProductPhoto 
(
    ThumbnailPhoto, 
    ThumbnailPhotoFilePath, 
    LargePhoto, 
    LargePhotoFilePath
)
SELECT ThumbnailPhoto.*, null, null, N'tricycle_pink.gif'
FROM OPENROWSET 
    (BULK 'c:\images\tricycle.jpg', SINGLE_BLOB) ThumbnailPhoto

Take a look at the following documentation for a good example/walkthrough

Working With Large Value Types

Note that the file path in this case is relative to the targeted SQL server and not your client running this command.

How can I easily add storage to a VirtualBox machine with XP installed?

Taked from here => forums.virtualbox.org/viewtopic.php?p=41118#p41118

You could try something like this (see also Tutorial - All about VDIs: How can I resize the partitions inside my VDI?):

  • Create a new VDI of the desired size.
  • Boot GParted Live in a VM with both old and new VDIs attached.
  • Check in the partition editor (opened automatically after booting) what your old and new disk locations are. (It'll be something like /dev/hda and /dev/hdb.)

  • Copy contents from old to new disk. This will take a fair amount of time. (Here /dev/hdX is your original disk and /dev/hdY the new one).

    dd if=/dev/hdX of=/dev/hdY

    Warning: Make sure you do not mix up your input and output disks or you'll wipe all information from your original disk! (if= specifies the input and of= specifies the output.)

  • Reboot (again with GParted-Live). Now you should be able to increase the Windows partition size on the new disk.

Once you've verified the larger VDI boots Windows fine (and disk size is as you'd expect) you can of course delete the old smaller VDI.

Edit: Instead of rebooting before you resize the partition you should be able to run partprobe and the hit CTRL+R in GParted instead.

How to make PopUp window in java

 
public class JSONPage {
    Logger log = Logger.getLogger("com.prodapt.autotest.gui.design.EditTestData");


    public static final JFrame JSONFrame = new JFrame();
    public final JPanel jPanel = new JPanel();

    JLabel IdLabel = new JLabel("JSON ID*");
    JLabel DataLabel = new JLabel("JSON Data*");
    JFormattedTextField JId = new JFormattedTextField("Auto Generated");
    JTextArea JData = new JTextArea();
    JButton Cancel = new JButton("Cancel");
    JButton Add = new JButton("Add");

    public void JsonPage() {

        JSONFrame.getContentPane().add(jPanel);
        JSONFrame.add(jPanel);
        JSONFrame.setSize(400, 250);
        JSONFrame.setResizable(false);
        JSONFrame.setVisible(false);
        JSONFrame.setTitle("Add JSON Data");
        JSONFrame.setLocationRelativeTo(null);
        jPanel.setLayout(null);

        JData.setWrapStyleWord(true);
        JId.setEditable(false);

        IdLabel.setBounds(20, 30, 120, 25);
        JId.setBounds(100, 30, 120, 25);
        DataLabel.setBounds(20, 60, 120, 25);
        JData.setBounds(100, 60, 250, 75);
        Cancel.setBounds(80, 170, 80, 30);
        Add.setBounds(280, 170, 50, 30);

        jPanel.add(IdLabel);
        jPanel.add(JId);
        jPanel.add(DataLabel);
        jPanel.add(JData);
        jPanel.add(Cancel);
        jPanel.add(Add);

        SwingUtilities.updateComponentTreeUI(JSONFrame);

        Cancel.addActionListener(new ActionListener() {
            @SuppressWarnings("deprecation")
            @Override
            public void actionPerformed(ActionEvent e) {
                JData.setText("");
                JSONFrame.hide();
                TestCasePage.testCaseFrame.show();
            }
        });

        Add.addActionListener(new ActionListener() {
            @SuppressWarnings("deprecation")
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    PreparedStatement pStatement = DAOHelper.getInstance()
                            .createJSON(
                                    ConnectionClass.getInstance()
                                            .getConnection());
                    pStatement.setString(1, null);
                    if (JData.getText().toString().isEmpty()) {
                        JOptionPane.showMessageDialog(JSONFrame,
                                "Must Enter JSON Path");
                    } else {
                        // System.out.println(eleSelectBy);
                        pStatement.setString(2, JData.getText());
                        pStatement.executeUpdate();
                        JOptionPane.showMessageDialog(JSONFrame, "!! Added !!");
                        log.info("JSON Path Added"+JData);
                        JData.setText("");
                        JSONFrame.hide();
                    }

                } catch (SQLException e1) {
                    JData.setText("");
                    log.info("Error in Adding JSON Path");
                    e1.printStackTrace();
                }
            }
        });
    }

}

Intercept and override HTTP requests from WebView

This may helps:

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
@Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
    String url = request.getUrl().toString();
    WebResourceResponse response = super.shouldInterceptRequest(view, request);
    // load native js
    if (url != null && url.contains(INJECTION_TOKEN/* scheme define */)) {

        response = new WebResourceResponse(
                "text/javascript",
                "utf-8",
                loadJsInputStream(url, JsCache.getJsFilePath(path) /* InputStream */));
    }
    return response;
}

Return array from function

neater:

function BlockID() {
  return {
    "s":"Images/Block_01.png",
    "g":"Images/Block_02.png",
    "C":"Images/Block_03.png",
    "d":"Images/Block_04.png"
   }
}

or just

var images = {
  "s":"Images/Block_01.png",
  "g":"Images/Block_02.png",
  "C":"Images/Block_03.png",
  "d":"Images/Block_04.png"
}

Swift 2: Call can throw, but it is not marked with 'try' and the error is not handled

When calling a function that is declared with throws in Swift, you must annotate the function call site with try or try!. For example, given a throwing function:

func willOnlyThrowIfTrue(value: Bool) throws {
  if value { throw someError }
}

this function can be called like:

func foo(value: Bool) throws {
  try willOnlyThrowIfTrue(value)
}

Here we annotate the call with try, which calls out to the reader that this function may throw an exception, and any following lines of code might not be executed. We also have to annotate this function with throws, because this function could throw an exception (i.e., when willOnlyThrowIfTrue() throws, then foo will automatically rethrow the exception upwards.

If you want to call a function that is declared as possibly throwing, but which you know will not throw in your case because you're giving it correct input, you can use try!.

func bar() {
  try! willOnlyThrowIfTrue(false)
}

This way, when you guarantee that code won't throw, you don't have to put in extra boilerplate code to disable exception propagation.

try! is enforced at runtime: if you use try! and the function does end up throwing, then your program's execution will be terminated with a runtime error.

Most exception handling code should look like the above: either you simply propagate exceptions upward when they occur, or you set up conditions such that otherwise possible exceptions are ruled out. Any clean up of other resources in your code should occur via object destruction (i.e. deinit()), or sometimes via defered code.

func baz(value: Bool) throws {

  var filePath = NSBundle.mainBundle().pathForResource("theFile", ofType:"txt")
  var data = NSData(contentsOfFile:filePath)

  try willOnlyThrowIfTrue(value)

  // data and filePath automatically cleaned up, even when an exception occurs.
}

If for whatever reason you have clean up code that needs to run but isn't in a deinit() function, you can use defer.

func qux(value: Bool) throws {
  defer {
    print("this code runs when the function exits, even when it exits by an exception")
  }

  try willOnlyThrowIfTrue(value)
}

Most code that deals with exceptions simply has them propagate upward to callers, doing cleanup on the way via deinit() or defer. This is because most code doesn't know what to do with errors; it knows what went wrong, but it doesn't have enough information about what some higher level code is trying to do in order to know what to do about the error. It doesn't know if presenting a dialog to the user is appropriate, or if it should retry, or if something else is appropriate.

Higher level code, however, should know exactly what to do in the event of any error. So exceptions allow specific errors to bubble up from where they initially occur to the where they can be handled.

Handling exceptions is done via catch statements.

func quux(value: Bool) {
  do {
    try willOnlyThrowIfTrue(value)
  } catch {
    // handle error
  }
}

You can have multiple catch statements, each catching a different kind of exception.

  do {
    try someFunctionThatThowsDifferentExceptions()
  } catch MyErrorType.errorA {
    // handle errorA
  } catch MyErrorType.errorB {
    // handle errorB
  } catch {
    // handle other errors
  }

For more details on best practices with exceptions, see http://exceptionsafecode.com/. It's specifically aimed at C++, but after examining the Swift exception model, I believe the basics apply to Swift as well.

For details on the Swift syntax and error handling model, see the book The Swift Programming Language (Swift 2 Prerelease).

How to create an integer array in Python?

 
>>> a = [0] * 10
>>> a
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

Basic authentication for REST API using spring restTemplate

There are multiple ways to add the basic HTTP authentication to the RestTemplate.

1. For a single request

try {
    // request url
    String url = "https://jsonplaceholder.typicode.com/posts";

    // create auth credentials
    String authStr = "username:password";
    String base64Creds = Base64.getEncoder().encodeToString(authStr.getBytes());

    // create headers
    HttpHeaders headers = new HttpHeaders();
    headers.add("Authorization", "Basic " + base64Creds);

    // create request
    HttpEntity request = new HttpEntity(headers);

    // make a request
    ResponseEntity<String> response = new RestTemplate().exchange(url, HttpMethod.GET, request, String.class);

    // get JSON response
    String json = response.getBody();

} catch (Exception ex) {
    ex.printStackTrace();
}

If you are using Spring 5.1 or higher, it is no longer required to manually set the authorization header. Use headers.setBasicAuth() method instead:

// create headers
HttpHeaders headers = new HttpHeaders();
headers.setBasicAuth("username", "password");

2. For a group of requests

@Service
public class RestService {

    private final RestTemplate restTemplate;

    public RestService(RestTemplateBuilder restTemplateBuilder) {
        this.restTemplate = restTemplateBuilder
                .basicAuthentication("username", "password")
                .build();
    }

   // use `restTemplate` instance here
}

3. For each and every request

@Bean
RestOperations restTemplateBuilder(RestTemplateBuilder restTemplateBuilder) {
    return restTemplateBuilder.basicAuthentication("username", "password").build();
}

I hope it helps!

Ineligible Devices section appeared in Xcode 6.x.x

Everyone should note that there seems to be a bug in XCode 6.3 (Beta and GM) that is aggravating this problem.

I have iOS 8.3 installed on my device. Setting the build target to iOS <= 8.3 did not help. Nor did any of the other solutions posted.

What worked for me:

Go to the Product Menu > Destination and select your device. It will be listed under "Ineligible", but you will still be able to select it. After doing this, I was able to build and deploy to my device.

Screenshot

Sort a list by multiple attributes?

It appears you could use a list instead of a tuple. This becomes more important I think when you are grabbing attributes instead of 'magic indexes' of a list/tuple.

In my case I wanted to sort by multiple attributes of a class, where the incoming keys were strings. I needed different sorting in different places, and I wanted a common default sort for the parent class that clients were interacting with; only having to override the 'sorting keys' when I really 'needed to', but also in a way that I could store them as lists that the class could share

So first I defined a helper method

def attr_sort(self, attrs=['someAttributeString']:
  '''helper to sort by the attributes named by strings of attrs in order'''
  return lambda k: [ getattr(k, attr) for attr in attrs ]

then to use it

# would defined elsewhere but showing here for consiseness
self.SortListA = ['attrA', 'attrB']
self.SortListB = ['attrC', 'attrA']
records = .... #list of my objects to sort
records.sort(key=self.attr_sort(attrs=self.SortListA))
# perhaps later nearby or in another function
more_records = .... #another list
more_records.sort(key=self.attr_sort(attrs=self.SortListB))

This will use the generated lambda function sort the list by object.attrA and then object.attrB assuming object has a getter corresponding to the string names provided. And the second case would sort by object.attrC then object.attrA.

This also allows you to potentially expose outward sorting choices to be shared alike by a consumer, a unit test, or for them to perhaps tell you how they want sorting done for some operation in your api by only have to give you a list and not coupling them to your back end implementation.

How can I send mail from an iPhone application

To send an email from iPhone application you need to do below list of task.

Step 1: Import #import <MessageUI/MessageUI.h> In your controller class where you want to send an email.

Step 2: Add the delegate to your controller like shown below

 @interface <yourControllerName> : UIViewController <MFMessageComposeViewControllerDelegate, MFMailComposeViewControllerDelegate>

Step 3: Add below method for send email.

 - (void) sendEmail {
 // Check if your app support the email.
 if ([MFMailComposeViewController canSendMail]) {
    // Create an object of mail composer.
    MFMailComposeViewController *mailComposer =      [[MFMailComposeViewController alloc] init];
    // Add delegate to your self.
    mailComposer.mailComposeDelegate = self;
    // Add recipients to mail if you do not want to add default recipient then remove below line.
    [mailComposer setToRecipients:@[<add here your recipient objects>]];
    // Write email subject.
    [mailComposer setSubject:@“<Your Subject Here>”];
    // Set your email body and if body contains HTML then Pass “YES” in isHTML.
    [mailComposer setMessageBody:@“<Your Message Body>” isHTML:NO];
    // Show your mail composer.
    [self presentViewController:mailComposer animated:YES completion:NULL];
 }
 else {
 // Here you can show toast to user about not support to sending email.
}
}

Step 4: Implement MFMailComposeViewController Delegate

- (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(nullable NSError *)error {
[controller dismissViewControllerAnimated:TRUE completion:nil];


switch (result) {
   case MFMailComposeResultSaved: {
    // Add code on save mail to draft.
    break;
}
case MFMailComposeResultSent: {
    // Add code on sent a mail.
    break;
}
case MFMailComposeResultCancelled: {
    // Add code on cancel a mail.
    break;
}
case MFMailComposeResultFailed: {
    // Add code on failed to send a mail.
    break;
}
default:
    break;
}
}

Uncaught ReferenceError: angular is not defined - AngularJS not working

You need to move your angular app code below the inclusion of the angular libraries. At the time your angular code runs, angular does not exist yet. This is an error (see your dev tools console).

In this line:

var app = angular.module(`

you are attempting to access a variable called angular. Consider what causes that variable to exist. That is found in the angular.js script which must then be included first.

  <h1>{{2+3}}</h1>

  <!-- In production use:
  <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.min.js"></script>
  -->
  <script src="lib/angular/angular.js"></script>
  <script src="lib/angular/angular-route.js"></script>
  <script src="js/app.js"></script>
  <script src="js/services.js"></script>
  <script src="js/controllers.js"></script>
  <script src="js/filters.js"></script>
  <script src="js/directives.js"></script>

      <script>
        var app = angular.module('myApp',[]);

        app.directive('myDirective',function(){

            return function(scope, element,attrs) {
                element.bind('click',function() {alert('click')});
            };

        });
    </script>

For completeness, it is true that your directive is similar to the already existing directive ng-click, but I believe the point of this exercise is just to practice writing simple directives, so that makes sense.

How to convert XML to JSON in Python?

Jacob Smullyan wrote a utility called pesterfish which uses effbot's ElementTree to convert XML to JSON.

How to remove duplicates from a list?

Nearly all of the above answers are right but what I suggest is to use a Map or Set while creating the related list, not after to gain performance. Because converting a list to a Set or Map and then reconverting it to a List again is a trivial work.

Sample Code:

Set<String> stringsSet = new LinkedHashSet<String>();//A Linked hash set 
//prevents the adding order of the elements
for (String string: stringsList) {
    stringsSet.add(string);
}
return new ArrayList<String>(stringsSet);

Error:Unable to locate adb within SDK in Android Studio

I get the error message, but adb.exe runs anyway (and debugging works fine), so its not a problem (apart from the error message being annoying). My best guess is that more than one process is trying to start the program at the same time.

Fastest way to get the first n elements of a List into an Array

Option 3

Iterators are faster than using the get operation, since the get operation has to start from the beginning if it has to do some traversal. It probably wouldn't make a difference in an ArrayList, but other data structures could see a noticeable speed difference. This is also compatible with things that aren't lists, like sets.

String[] out = new String[n];
Iterator<String> iterator = in.iterator();
for (int i = 0; i < n && iterator.hasNext(); i++)
    out[i] = iterator.next();

Vertical align middle with Bootstrap responsive grid

Add !important rule to display: table of your .v-center class. 

.v-center {
    display:table !important;
    border:2px solid gray;
    height:300px;
}

Your display property is being overridden by bootstrap to display: block.

Example

Oracle PL/SQL : remove "space characters" from a string

Since you're comfortable with regular expressions, you probably want to use the REGEXP_REPLACE function. If you want to eliminate anything that matches the [:space:] POSIX class

REGEXP_REPLACE( my_value, '[[:space:]]', '' )


SQL> ed
Wrote file afiedt.buf

  1  select '|' ||
  2         regexp_replace( 'foo ' || chr(9), '[[:space:]]', '' ) ||
  3         '|'
  4*   from dual
SQL> /

'|'||
-----
|foo|

If you want to leave one space in place for every set of continuous space characters, just add the + to the regular expression and use a space as the replacement character.

with x as (
  select 'abc 123  234     5' str
    from dual
)
select regexp_replace( str, '[[:space:]]+', ' ' )
  from x

How can I get an int from stdio in C?

I'm not fully sure that this is what you're looking for, but if your question is how to read an integer using <stdio.h>, then the proper syntax is

int myInt;
scanf("%d", &myInt);

You'll need to do a lot of error-handling to ensure that this works correctly, of course, but this should be a good start. In particular, you'll need to handle the cases where

  1. The stdin file is closed or broken, so you get nothing at all.
  2. The user enters something invalid.

To check for this, you can capture the return code from scanf like this:

int result = scanf("%d", &myInt);

If stdin encounters an error while reading, result will be EOF, and you can check for errors like this:

int myInt;
int result = scanf("%d", &myInt);

if (result == EOF) {
    /* ... you're not going to get any input ... */
}

If, on the other hand, the user enters something invalid, like a garbage text string, then you need to read characters out of stdin until you consume all the offending input. You can do this as follows, using the fact that scanf returns 0 if nothing was read:

int myInt;
int result = scanf("%d", &myInt);

if (result == EOF) {
    /* ... you're not going to get any input ... */
}
if (result == 0) {
    while (fgetc(stdin) != '\n') // Read until a newline is found
        ;
}

Hope this helps!

EDIT: In response to the more detailed question, here's a more appropriate answer. :-)

The problem with this code is that when you write

printf("got the number: %d", scanf("%d", &x));

This is printing the return code from scanf, which is EOF on a stream error, 0 if nothing was read, and 1 otherwise. This means that, in particular, if you enter an integer, this will always print 1 because you're printing the status code from scanf, not the number you read.

To fix this, change this to

int x;
scanf("%d", &x);
/* ... error checking as above ... */
printf("got the number: %d", x);

Hope this helps!

How to iterate through a String

Using Guava (r07) you can do this:

for(char c : Lists.charactersOf(someString)) { ... }

This has the convenience of using foreach while not copying the string to a new array. Lists.charactersOf returns a view of the string as a List.

How to get a value inside an ArrayList java

The list may contain several elements, so the get method takes an argument : the index of the element you want to retrieve. If you want the first one, then it's 0.

The list contains Car instances, so you just have to do

Car firstCar = car.get(0);
String price = firstCar.getPrice();

or just

String price = car.get(0).getPrice();

The car variable should be named cars, since it's a list and thus contains several cars.

Read the tutorial about collections. And learn to use the javadoc: all the classes and methods are documented.

How to add \newpage in Rmarkdown in a smart way?

In the initialization chunk I define a function

pagebreak <- function() {
  if(knitr::is_latex_output())
    return("\\newpage")
  else
    return('<div style="page-break-before: always;" />')
}

In the markdown part where I want to insert a page break, I type 

`r pagebreak()`

Adding an item to an associative array

You can simply do this

$data += array($category => $question);

If your're running on php 5.4+

$data += [$category => $question];

Generating an array of letters in the alphabet

I wrote this to get the MS excel column code (A,B,C, ..., Z, AA, AB, ..., ZZ, AAA, AAB, ...) based on a 1-based index. (Of course, switching to zero-based is simply leaving off the column--; at the start.)

public static String getColumnNameFromIndex(int column)
{
    column--;
    String col = Convert.ToString((char)('A' + (column % 26)));
    while (column >= 26)
    {
        column = (column / 26) -1;
        col = Convert.ToString((char)('A' + (column % 26))) + col;
    }
    return col;
}

VC++ fatal error LNK1168: cannot open filename.exe for writing

The Reason is that your previous build is still running in the background. I solve this problem by following these steps:

  • Open Task Manager
  • Goto Details Tab
  • Find Your Application
  • End Task it by right clicking on it
  • Done!

Parsing boolean values with argparse

I was looking for the same issue, and imho the pretty solution is :

def str2bool(v):
  return v.lower() in ("yes", "true", "t", "1")

and using that to parse the string to boolean as suggested above.

SQL to Query text in access with an apostrophe in it

You escape ' by doubling it, so:

Select * from tblStudents where name like 'Daniel O''Neal'

Note that if you're accepting "Daniel O'Neal" from user input, the broken quotation is a serious security issue. You should always sanitize the string or use parametrized queries.

Emulate a 403 error page

Use ModRewrite:

RewriteRule ^403.html$ - [F]

Just make sure you create a blank document called "403.html" in your www root or you'll get a 404 error instead of 403.

Postgres integer arrays as parameters?

See: http://www.postgresql.org/docs/9.1/static/arrays.html

If your non-native driver still does not allow you to pass arrays, then you can:

  • pass a string representation of an array (which your stored procedure can then parse into an array -- see string_to_array)

    CREATE FUNCTION my_method(TEXT) RETURNS VOID AS $$ 
DECLARE
       ids INT[];
BEGIN
       ids = string_to_array($1,',');
       ...
END $$ LANGUAGE plpgsql;

    then

    SELECT my_method(:1)

    with :1 = '1,2,3,4'

  • rely on Postgres itself to cast from a string to an array

    CREATE FUNCTION my_method(INT[]) RETURNS VOID AS $$ 
       ...
END $$ LANGUAGE plpgsql;

    then

    SELECT my_method('{1,2,3,4}')

  • choose not to use bind variables and issue an explicit command string with all parameters spelled out instead (make sure to validate or escape all parameters coming from outside to avoid SQL injection attacks.)

    CREATE FUNCTION my_method(INT[]) RETURNS VOID AS $$ 
       ...
END $$ LANGUAGE plpgsql;

    then

    SELECT my_method(ARRAY [1,2,3,4])

Is it possible to implement a Python for range loop without an iterator variable?

I generally agree with solutions given above. Namely with:

  1. Using underscore in for-loop (2 and more lines)
  2. Defining a normal while counter (3 and more lines)
  3. Declaring a custom class with __nonzero__ implementation (many more lines)

If one is to define an object as in #3 I would recommend implementing protocol for with keyword or apply contextlib.

Further I propose yet another solution. It is a 3 liner and is not of supreme elegance, but it uses itertools package and thus might be of an interest.

from itertools import (chain, repeat)

times = chain(repeat(True, 2), repeat(False))
while next(times):
    print 'do stuff!'

In these example 2 is the number of times to iterate the loop. chain is wrapping two repeat iterators, the first being limited but the second is infinite. Remember that these are true iterator objects, hence they do not require infinite memory. Obviously this is much slower then solution #1. Unless written as a part of a function it might require a clean up for times variable.

Which Java library provides base64 encoding/decoding?

Within Apache Commons, commons-codec-1.7.jar contains a Base64 class which can be used to encode.

Via Maven:

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
    <version>20041127.091804</version>
</dependency>

Direct Download

How to verify Facebook access token?

I found this official tool from facebook developer page, this page will you following information related to access token - App ID, Type, App-Scoped,User last installed this app via, Issued, Expires, Data Access Expires, Valid, Origin, Scopes. Just need access token.

https://developers.facebook.com/tools/debug/accesstoken/

What is the difference between ports 465 and 587?

I don't want to name names, but someone appears to be completely wrong. The referenced standards body stated the following: submissions 465 tcp Message Submission over TLS protocol [IESG] [IETF_Chair] 2017-12-12 [RFC8314]

If you are so inclined, you may wish to read the referenced RFC.

This seems to clearly imply that port 465 is the best way to force encrypted communication and be sure that it is in place. Port 587 offers no such guarantee.

Add a reference column migration in Rails 4

Just to document if someone has the same problem...

In my situation I've been using :uuid fields, and the above answers does not work to my case, because rails 5 are creating a column using :bigint instead :uuid:

add_reference :uploads, :user, index: true, type: :uuid

Reference: Active Record Postgresql UUID

Why is the Java main method static?

The public keyword is an access modifier, which allows the programmer to control the visibility of class members. When a class member is preceded by public, then that member may be accessed by code outside the class in which it is declared.

The opposite of public is private, which prevents a member from being used by code defined outside of its class.

In this case, main() must be declared as public, since it must be called by code outside of its class when the program is started.

The keyword static allows main() to be called without having to instantiate a particular instance of the class. This is necessary since main() is called by the Java interpreter before any objects are made.

The keyword void simply tells the compiler that main() does not return a value.

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

 
string s = "hello";
char c = s[1];
// now c == 'e'

See also Substring, to return more than one character.

How to show one layout on top of the other programmatically in my case?

FrameLayout is not the better way to do this:

Use RelativeLayout instead. You can position the elements anywhere you like. The element that comes after, has the higher z-index than the previous one (i.e. it comes over the previous one).

Example:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent" android:layout_height="match_parent">
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/colorPrimary"
        app:srcCompat="@drawable/ic_information"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="This is a text."
        android:layout_centerHorizontal="true"
        android:layout_alignParentBottom="true"
        android:layout_margin="8dp"
        android:padding="5dp"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:background="#A000"
        android:textColor="@android:color/white"/>
</RelativeLayout>

enter image description here

The most efficient way to implement an integer based power function pow(int, int)

I use recursive, if the exp is even,5^10 =25^5.

int pow(float base,float exp){
   if (exp==0)return 1;
   else if(exp>0&&exp%2==0){
      return pow(base*base,exp/2);
   }else if (exp>0&&exp%2!=0){
      return base*pow(base,exp-1);
   }
}

Error message "Forbidden You don't have permission to access / on this server"

I was getting the same error and couldn't figure out the problem for ages. If you happen to be on a Linux distribution that includes SELinux such as CentOS, you need to make sure SELinux permissions are set correctly for your document root files or you will get this error. This is a completely different set of permissions to the standard file system permissions.

I happened to use the tutorial Apache and SELinux, but there seems to be plenty around once you know what to look for.

jquery find class and get the value

You can get value of id,name or value in this way. class name my_class

 var id_value = $('.my_class').$(this).attr('id'); //get id value
 var name_value = $('.my_class').$(this).attr('name'); //get name value
 var value = $('.my_class').$(this).attr('value'); //get value any input or tag

Spring Boot: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean

Adding the annotation @SpringBootApplication Before the starter class fixed this problem for me (so in essence, this error message can mean "you don't have a @SpringBootApplication marked class anywhere, you need at least one)

@SpringBootApplication
public class AppStarter {

    public static void main(String[] args) {
        SpringApplication.run(AppStarter.class, args);
    }
}

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

The main difference is that DATETIME is constant while TIMESTAMP is affected by the time_zone setting.

So it only matters when you have — or may in the future have — synchronized clusters across time zones.

In simpler words: If I have a database in Australia, and take a dump of that database to synchronize/populate a database in America, then the TIMESTAMP would update to reflect the real time of the event in the new time zone, while DATETIME would still reflect the time of the event in the au time zone.

A great example of DATETIME being used where TIMESTAMP should have been used is in Facebook, where their servers are never quite sure what time stuff happened across time zones. Once I was having a conversation in which the time said I was replying to messages before the message was actually sent. (This, of course, could also have been caused by bad time zone translation in the messaging software if the times were being posted rather than synchronized.)

Two submit buttons in one form

 
<form>
    <input type="submit" value="Submit to a" formaction="/submit/a">
    <input type="submit" value="submit to b" formaction="/submit/b">    
</form>

node.js hash string?

Even if the hash is not for security, you can use sha instead of md5. In my opinion, the people should forget about md5 for now, it's in the past!

The normal nodejs sha256 is deprecated. So, you have two alternatives for now:

var shajs = require('sha.js')  - https://www.npmjs.com/package/sha.js (used by Browserify)

var hash = require('hash.js')  - https://github.com/indutny/hash.js

I prefer using shajs instead of hash, because I consider sha the best hash function nowadays and you don't need a different hash function for now. So to get some hash in hex you should do something like the following: 

sha256.update('hello').digest('hex')

How to call javascript from a href?

 
<a href="javascript:call_func();">...</a>

where the function then has to return false so that the browser doesn't go to another page.

But I'd recommend to use jQuery (with $(...).click(function () {})))

Detecting arrow key presses in JavaScript

I was also looking for this answer until I came across this post.

I've found another solution to know the keycode of the different keys, courtesy to my problem. I just wanted to share my solution.

Just use keyup/keydown event to write the value in the console/alert the same using event.keyCode. like-

console.log(event.keyCode) 

// or

alert(event.keyCode)

- rupam

Add data dynamically to an Array

Like this?:

$array[] = 'newItem';

Vertical Tabs with JQuery?

Try here:

http://www.sunsean.com/idTabs/

A look at the Freedom tab might have what you need.

Let me know if you find something you like. I worked on the exact same problem a few months ago and decided to implement myself. I like what I did, but it might have been nice to use a standard library.

Way to get all alphabetic chars in an array in PHP?

Try this : 

function missingCharacter($list) {

        // Create an array with a range from array minimum to maximu
        $newArray = range(min($list), max($list));

        // Find those elements that are present in the $newArray but not in given $list
        return array_diff($newArray, $list);
    }
print_r(missCharacter(array('a','b','d','g')));

INSTALL_FAILED_DUPLICATE_PERMISSION... C2D_MESSAGE

I uninstalled previous version. It worked for me.

Running conda with proxy

The best way I settled with is to set proxy environment variables right before using conda or pip install/update commands. Simply run:

set HTTP_PROXY=http://username:password@proxy_url:port

For example, your actual command could be like

set HTTP_PROXY=http://yourname:[email protected]_company.com:8080

If your company uses https proxy, then also

set HTTPS_PROXY=https://username:password@proxy_url:port

Once you exit Anaconda prompt then this setting is gone, so your username/password won't be saved after the session.

I didn't choose other methods mentioned in Anaconda documentation or some other sources, because they all require hardcoding of username/password into

  • Windows environment variables (also this requires restart of Anaconda prompt for the first time)
  • Conda .condarc or .netrc configuration files (also this won't work for PIP)
  • A batch/script file loaded while starting Anaconda prompt (also this might require configuring the path)

All of these are unsafe and will require constant update later. And if you forget where to update? More troubleshooting will come your way...

Cleanest way to build an SQL string in Java

I am wondering if you are after something like Squiggle. Also something very useful is jDBI. It won't help you with the queries though.

How do I find the caller of a method using stacktrace or reflection?

Sounds like you're trying to avoid passing a reference to this into the method. Passing this is way better than finding the caller through the current stack trace. Refactoring to a more OO design is even better. You shouldn't need to know the caller. Pass a callback object if necessary.

invalid command code ., despite escaping periods, using sed

If you are on a OS X, this probably has nothing to do with the sed command. On the OSX version of sed, the -i option expects an extension argument so your command is actually parsed as the extension argument and the file path is interpreted as the command code.

Try adding the -e argument explicitly and giving '' as argument to -i:

find ./ -type f -exec sed -i '' -e "s/192.168.20.1/new.domain.com/" {} \;

See this.

Can't accept license agreement Android SDK Platform 24
  1. Go to Android SDK location

C:\Users\username\AppData\Local\Android\sdk\tools\bin

  1. Run command sdkmanager --licenses

  2. Accept the licence for SDK

Get total number of items on Json object?

Is that your actual code? A javascript object (which is what you've given us) does not have a length property, so in this case exampleArray.length returns undefined rather than 5.

This stackoverflow explains the length differences between an object and an array, and this stackoverflow shows how to get the 'size' of an object.

SQL Server FOR EACH Loop

Off course an old question. But I have a simple solution where no need of Looping, CTE, Table variables etc.

DECLARE @MyVar datetime = '1/1/2010'    
SELECT @MyVar

SELECT DATEADD (DD,NUMBER,@MyVar) 
FROM master.dbo.spt_values 
WHERE TYPE='P' AND NUMBER BETWEEN 0 AND 4 
ORDER BY NUMBER

Note : spt_values is a Mircrosoft's undocumented table. It has numbers for every type. Its not suggestible to use as it can be removed in any new versions of sql server without prior information, since it is undocumented. But we can use it as quick workaround in some scenario's like above.

How to get the full path of running process?

For others, if you want to find another process of the same executable, you can use:

public bool tryFindAnotherInstance(out Process process) {
    Process thisProcess = Process.GetCurrentProcess();
    string thisFilename = thisProcess.MainModule.FileName;
    int thisPId = thisProcess.Id;
    foreach (Process p in Process.GetProcesses())
    {
        try
        {
            if (p.MainModule.FileName == thisFilename && thisPId != p.Id)
            {
                process = p;
                return true;
            }
        }
        catch (Exception)
        {

        }
    }
    process = default;
    return false;
}

Simplest way to set image as JPanel background

Simplest way to set image as JPanel background

Don't use a JPanel. Just use a JLabel with an Icon then you don't need custom code.

See Background Panel for more information as well as a solution that will paint the image on a JPanel with 3 different painting options:

  1. scaled
  2. tiled
  3. actual

File tree view in Notepad++

As of Notepad++ 6.9, the new Folder as Workspace feature can be used.

Folder as Workspace opens your folder(s) in a panel so you can browse folder(s) and open any file in Notepad++. Every changement in the folder(s) from outside will be synchronized in the panel. Usage: Simply drop 1 (or more) folder(s) in Notepad++.

Folder as Workspace

This feature has the advantage of not showing your entire file system when just the working directory is needed. It also means you don't need plugins for it to work.

How can I remove an element from a list?

I don't know R at all, but a bit of creative googling led me here: http://tolstoy.newcastle.edu.au/R/help/05/04/1919.html

The key quote from there:

I do not find explicit documentation for R on how to remove elements from lists, but trial and error tells me

myList[[5]] <- NULL

will remove the 5th element and then "close up" the hole caused by deletion of that element. That suffles the index values, So I have to be careful in dropping elements. I must work from the back of the list to the front.

A response to that post later in the thread states:

For deleting an element of a list, see R FAQ 7.1

And the relevant section of the R FAQ says:

... Do not set x[i] or x[[i]] to NULL, because this will remove the corresponding component from the list.

Which seems to tell you (in a somewhat backwards way) how to remove an element.

Hope that helps, or at least leads you in the right direction.

JList add/remove Item

The best and easiest way to clear a JLIST is:

myJlist.setListData(new String[0]);

String parsing in Java with delimiter tab "\t" using split

String.split uses Regular Expressions, also you don't need to allocate an extra array for your split.

The split-method will give you a list., the problem is that you try to pre-define how many occurrences you have of a tab, but how would you Really know that? Try using the Scanner or StringTokenizer and just learn how splitting strings work.

Let me explain Why \t does not work and why you need \\\\ to escape \\.

Okay, so when you use Split, it actually takes a regex ( Regular Expression ) and in regular expression you want to define what Character to split by, and if you write \t that actually doesn't mean \t and what you WANT to split by is \t, right? So, by just writing \t you tell your regex-processor that "Hey split by the character that is escaped t" NOT "Hey split by all characters looking like \t". Notice the difference? Using \ means to escape something. And \ in regex means something Totally different than what you think.

So this is why you need to use this Solution:

\\t

To tell the regex processor to look for \t. Okay, so why would you need two of em? Well, the first \ escapes the second, which means it will look like this: \t when you are processing the text!

Now let's say that you are looking to split \

Well then you would be left with \\ but see, that doesn't Work! because \ will try to escape the previous char! That is why you want the Output to be \\ and therefore you need to have \\\\.

I really hope the examples above helps you understand why your solution doesn't work and how to conquer other ones!

Now, I've given you this answer before, maybe you should start looking at them now.

OTHER METHODS

StringTokenizer

You should look into the StringTokenizer, it's a very handy tool for this type of work.

Example

 StringTokenizer st = new StringTokenizer("this is a test");
 while (st.hasMoreTokens()) {
     System.out.println(st.nextToken());
 }

This will output

 this
 is
 a
 test

You use the Second Constructor for StringTokenizer to set the delimiter:

StringTokenizer(String str, String delim)

Scanner

You could also use a Scanner as one of the commentators said this could look somewhat like this

Example

 String input = "1 fish 2 fish red fish blue fish";

 Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*");

 System.out.println(s.nextInt());
 System.out.println(s.nextInt());
 System.out.println(s.next());
 System.out.println(s.next());

 s.close();

The output would be 

 1
 2
 red
 blue

Meaning that it will cut out the word "fish" and give you the rest, using "fish" as the delimiter.

examples taken from the Java API

Unresolved external symbol in object files

My issue was a sconscript did not have the cpp file defined in it. This can be very confusing because Visual Studio has the cpp file in the project but something else entirely is building.

How do you perform a left outer join using linq extension methods

Group Join method is unnecessary to achieve joining of two data sets.

Inner Join:

var qry = Foos.SelectMany
            (
                foo => Bars.Where (bar => foo.Foo_id == bar.Foo_id),
                (foo, bar) => new
                    {
                    Foo = foo,
                    Bar = bar
                    }
            );

For Left Join just add DefaultIfEmpty()

var qry = Foos.SelectMany
            (
                foo => Bars.Where (bar => foo.Foo_id == bar.Foo_id).DefaultIfEmpty(),
                (foo, bar) => new
                    {
                    Foo = foo,
                    Bar = bar
                    }
            );

EF and LINQ to SQL correctly transform to SQL. For LINQ to Objects it is beter to join using GroupJoin as it internally uses Lookup. But if you are querying DB then skipping of GroupJoin is AFAIK as performant.

Personlay for me this way is more readable compared to GroupJoin().SelectMany()

How do I check if an HTML element is empty using jQuery?

 
if ($('#element').is(':empty')){
  //do something
}

for more info see http://api.jquery.com/is/ and http://api.jquery.com/empty-selector/

EDIT:

As some have pointed, the browser interpretation of an empty element can vary. If you would like to ignore invisible elements such as spaces and line breaks and make the implementation more consistent you can create a function (or just use the code inside of it).

  function isEmpty( el ){
      return !$.trim(el.html())
  }
  if (isEmpty($('#element'))) {
      // do something
  }

You can also make it into a jQuery plugin, but you get the idea.