No module named 'openpyxl' - Python 3.4 - Ubuntu

I had the same problem solved using instead of pip install :

sudo apt-get install python-openpyxl
sudo apt-get install python3-openpyxl

The sudo command also works better for other packages.

How do I resolve "HTTP Error 500.19 - Internal Server Error" on IIS7.0

so easy find the file "applicationHost.config" in Windows -> System32 ->inetsrv -> config 1. backup "applicationHost.config" to another filename 2. open file "applicationHost.config" clear data and save 3. open browser and call url internal website , finished.

bootstrap 3 wrap text content within div for horizontal alignment

1) Maybe oveflow: hidden; will do the trick?

2) You need to set the size of each div with the text and button so that each of these divs have the same height. Then for your button:

button {
  position: absolute;
  bottom: 0;
}

gpg failed to sign the data fatal: failed to write commit object [Git 2.10.0]

Using cygwin, I recently switched to gpg2. Then I had the same problem for signing with git after setting git config gpg.program gpg2.

Try echo "test" | gpg2 --clearsign to see whether gpg2 is working. I found it the easiest solution to just set git config gpg.program gpg, because that works. But you will also get a better error this way - e.g. that you need to install pinentry.

Where should I put <script> tags in HTML markup?

The standard advice, promoted by the Yahoo! Exceptional Performance team, is to put the <script> tags at the end of the document body so they don't block rendering of the page.

But there are some newer approaches that offer better performance, as described in this answer about the load time of the Google Analytics JavaScript file:

There are some great slides by Steve Souders (client-side performance expert) about:

Different techniques to load external JavaScript files in parallel

their effect on loading time and page rendering

what kind of "in progress" indicators the browser displays (e.g. 'loading' in the status bar, hourglass mouse cursor).

Check if element at position [x] exists in the list

if(list.ElementAtOrDefault(2) != null)
{
   // logic
}

ElementAtOrDefault() is part of the System.Linq namespace.

Although you have a List, so you can use list.Count > 2.

How to negate code in "if" statement block in JavaScript -JQuery like 'if not then..'

Try negation operator ! before $(this):

if (!$(this).parent().next().is('ul')){

Python `if x is not None` or `if not x is None`?

I would prefer the more readable form x is not y than I would think how to eventually write the code handling precedence of the operators in order to produce much more readable code.

How to compare timestamp dates with date-only parameter in MySQL?

As I was researching this I thought it would be nice to modify the BETWEEN solution to show an example for a particular non-static/string date, but rather a variable date, or today's such as CURRENT_DATE(). This WILL use the index on the log_timestamp column.

SELECT *
FROM some_table
WHERE
    log_timestamp
    BETWEEN 
        timestamp(CURRENT_DATE()) 
    AND # Adds 23.9999999 HRS of seconds to the current date
        timestamp(DATE_ADD(CURRENT_DATE(), INTERVAL '86399.999999' SECOND_MICROSECOND));

I did the seconds/microseconds to avoid the 12AM case on the next day. However, you could also do `INTERVAL '1 DAY' via comparison operators for a more reader-friendly non-BETWEEN approach:

SELECT *
FROM some_table
WHERE
    log_timestamp >= timestamp(CURRENT_DATE()) AND
    log_timestamp < timestamp(DATE_ADD(CURRENT_DATE(), INTERVAL 1 DAY));

Both of these approaches will use the index and should perform MUCH faster. Both seem to be equally as fast.

HTML page disable copy/paste

You cannot prevent people from copying text from your page. If you are trying to satisfy a "requirement" this may work for you:

<body oncopy="return false" oncut="return false" onpaste="return false">

How to disable Ctrl C/V using javascript for both internet explorer and firefox browsers

A more advanced aproach:

How to detect Ctrl+V, Ctrl+C using JavaScript?

Edit: I just want to emphasise that disabling copy/paste is annoying, won't prevent copying and is 99% likely a bad idea.

How can change width of dropdown list?

If you want to control the width of the list that drops down, you can do it as follows.

CSS

#wgtmsr option {
    width: 50px;
}

Can't concat bytes to str

subprocess.check_output() returns a bytestring.

In Python 3, there's no implicit conversion between unicode (str) objects and bytes objects. If you know the encoding of the output, you can .decode() it to get a string, or you can turn the \n you want to add to bytes with "\n".encode('ascii')

Get the filename of a fileupload in a document through JavaScript

Using code like this in a form I can capture the original source upload filename, copy it to a second simple input field. This is so user can provide an alternate upload filename in submit request since the file upload filename is immutable.

    <input type="file" id="imgup1" name="imagefile">
      onchange="document.getElementsByName('imgfn1')[0].value = document.getElementById('imgup1').value;">
    <input type="text" name="imgfn1" value="">

WP -- Get posts by category?

add_shortcode( 'seriesposts', 'series_posts' );

function series_posts( $atts )
{ ob_start();

$myseriesoption = get_option( '_myseries', null );

$type = $myseriesoption;
$args=array(  'post_type' => $type,  'post_status' => 'publish',  'posts_per_page' => 5,  'caller_get_posts'=> 1);
$my_query = null;
$my_query = new WP_Query($args);
if( $my_query->have_posts() ) {
echo '<ul>'; 
while ($my_query->have_posts()) : $my_query->the_post();
echo '<li><a href="';
echo the_permalink();
echo '">';
echo the_title();
echo '</a></li>'; 
endwhile;
echo '</ul>'; 
}
wp_reset_query();




return ob_get_clean(); }

//this will generate a shortcode function to be used on your site [seriesposts]

automating telnet session using bash scripts

Following is working for me... put all of your IPs you want to telnet in IP_sheet.txt

while true
read a
do
{
    sleep 3
    echo df -kh
    sleep 3
    echo exit
} | telnet $a
done<IP_sheet.txt

How do I check if a number is positive or negative in C#?

For a 32-bit signed integer, such as System.Int32, aka int in C#:

bool isNegative = (num & (1 << 31)) != 0;

How to host google web fonts on my own server?

Easiest Approach - Using `google-webfonts-helper`

Lets say we want to host the font `Red Rose`:

Open google-webfonts-helper and filter for the required font on top left (type Red Rose and enter..)
Choose from the charsets (default is latin; select others like latin-ext if you want extended support)
Select the styles (deafult is regular)
From the Copy CSS tab
- Select Modern Browser if you wish to support only modern browsers (woff2, woff)
- Select Best Support if you wish to support all browsers (I chose this - woff2, woff,ttf,svg,eot)
In case your font files do not reside in ../fonts/ path, you can edit it to represent your actual path (for me it was ../assets/fonts/)
Copy the CSS and keep for future use
Download the zip file named red-rose-v1-latin-ext_latin; unzip it and place all fonts directly into your assets/fonts directory (based on what you gave earlier)
In your stylesheet where you wish to embed, paste the copied CSS. It will look like the below if you chose these options

/* red-rose-regular - latin-ext_latin */
@font-face {
  font-family: 'Red Rose';
  font-style: normal;
  font-weight: 400;
  src: url('../assets/fonts/red-rose-v1-latin-ext_latin-regular.eot'); /* IE9 Compat Modes */
  src: local('Red Rose Regular'), local('RedRose-Regular'),
       url('../assets/fonts/red-rose-v1-latin-ext_latin-regular.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
       url('../assets/fonts/red-rose-v1-latin-ext_latin-regular.woff2') format('woff2'), /* Super Modern Browsers */
       url('../assets/fonts/red-rose-v1-latin-ext_latin-regular.woff') format('woff'), /* Modern Browsers */
       url('../assets/fonts/red-rose-v1-latin-ext_latin-regular.ttf') format('truetype'), /* Safari, Android, iOS */
       url('../assets/fonts/red-rose-v1-latin-ext_latin-regular.svg#RedRose') format('svg'); /* Legacy iOS */
}

/* Red Rose will now be available for use in your stylesheet, provide this font */

:root {
  font-family: 'Red Rose', cursive, sans-serif;
}

Thats ALL!

Use -notlike to filter out multiple strings in PowerShell

I think Peter has the right idea. I would use a regular expression for this along with the -notmatch operator.

Get-EventLog Security | ?{$_.Username -notmatch '^user1$|^.*user$'}

@UniqueConstraint annotation in Java

I'm currently using play framework too with hibernate and JPA 2.0 annotation and this model works without problems

@Entity
@Table(uniqueConstraints={@UniqueConstraint(columnNames = {"id_1" , "id_2"})})
public class class_name {

@Id
@GeneratedValue
public Long id;

@NotNull
public Long id_1;

@NotNull
public Long id_2;

}

Hope it helped.

Initializing ArrayList with some predefined values

Personnaly I like to do all the initialisations in the constructor

public Test()
{
  symbolsPresent = new ArrayList<String>();
  symbolsPresent.add("ONE");
  symbolsPresent.add("TWO");
  symbolsPresent.add("THREE");
  symbolsPresent.add("FOUR");
}

Edit : It is a choice of course and others prefer to initialize in the declaration. Both are valid, I have choosen the constructor because all type of initialitions are possible there (if you need a loop or parameters, ...). However I initialize the constants in the declaration on the top on the source.
The most important is to follow a rule that you like and be consistent in our classes.

How do I prevent a Gateway Timeout with FastCGI on Nginx

In http nginx section (/etc/nginx/nginx.conf) add or modify:

keepalive_timeout 300s

In server nginx section (/etc/nginx/sites-available/your-config-file.com) add these lines:

client_max_body_size 50M;
fastcgi_buffers 8 1600k;
fastcgi_buffer_size 3200k;
fastcgi_connect_timeout 300s;
fastcgi_send_timeout 300s;
fastcgi_read_timeout 300s;

In php file in the case 127.0.0.1:9000 (/etc/php/7.X/fpm/pool.d/www.conf) modify:

request_terminate_timeout = 300

I hope help you.

How to compile .c file with OpenSSL includes?

Use the -I flag to gcc properly.

gcc -I/path/to/openssl/ -o Opentest -lcrypto Opentest.c

The -I should point to the directory containing the openssl folder.

Spring Boot @autowired does not work, classes in different package

When I add @ComponentScan("com.firstday.spring.boot.services") or scanBasePackages{"com.firstday.spring.boot.services"} jsp is not loaded. So when I add the parent package of project in @SpringBootApplication class it's working fine in my case

Code Example:-

package com.firstday.spring.boot.firstday;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication(scanBasePackages = {"com.firstday.spring.boot"})
public class FirstDayApplication {

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

}

How to pass data from 2nd activity to 1st activity when pressed back? - android

From your FirstActivity call the SecondActivity using startActivityForResult() method.

For example:

Intent i = new Intent(this, SecondActivity.class);
startActivityForResult(i, 1);

In your SecondActivity set the data which you want to return back to FirstActivity. If you don't want to return back, don't set any.

For example: In secondActivity if you want to send back data:

Intent returnIntent = new Intent();
returnIntent.putExtra("result",result);
setResult(Activity.RESULT_OK,returnIntent);
finish();

If you don't want to return data:

Intent returnIntent = new Intent();
setResult(Activity.RESULT_CANCELED, returnIntent);
finish();

Now in your FirstActivity class write following code for the onActivityResult() method.

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1) {
        if(resultCode == Activity.RESULT_OK){
            String result=data.getStringExtra("result");
        }
        if (resultCode == Activity.RESULT_CANCELED) {
            //Write your code if there's no result
        }
    }
}

How to change color in markdown cells ipython/jupyter notebook?

If none of the above suggestions works for you, try using the style attribute.

**Notes**
<p style="color:red;">ERROR: Setting focus didn't work for me when I tried from jupyter. However it worked well when I ran it from the terminal</p>

This gives me the following result

jQuery autoComplete view all on click?

try this:

    $('#autocomplete').focus(function(){
        $(this).val('');
        $(this).keydown();
    });

and minLength set to 0

works every time :)

HTML5 Number Input - Always show 2 decimal places

import { Component, Pipe, PipeTransform } from '@angular/core';

@Pipe({
    name: 'replace'
})

export class ReplacePipe implements PipeTransform {
    transform(value: any): any {
        value = String(value).toString();
        var afterPoint = '';
        var plus = ',00';
        if (value.length >= 4) {
            if (value.indexOf('.') > 0) {
                afterPoint = value.substring(value.indexOf('.'), value.length);
                var te = afterPoint.substring(0, 3);
                if (te.length == 2) {
                    te = te + '0';
                }
            }
            if (value.indexOf('.') > 0) {
                if (value.indexOf('-') == 0) {
                    value = parseInt(value);
                    if (value == 0) {
                        value = '-' + value + te;
                        value = value.toString();
                    }
                    else {
                        value = value + te;
                        value = value.toString();
                    }
                }
                else {
                    value = parseInt(value);
                    value = value + te;
                    value = value.toString();
                }
            }
            else {
                value = value.toString() + plus;
            }
            var lastTwo = value.substring(value.length - 2);
            var otherNumbers = value.substring(0, value.length - 3);
            if (otherNumbers != '')
                lastTwo = ',' + lastTwo;
            let newValue = otherNumbers.replace(/\B(?=(\d{3})+(?!\d))/g, ".") + lastTwo;
            parseFloat(newValue);
            return `${newValue}`;
        }
}
}

Angular error: "Can't bind to 'ngModel' since it isn't a known property of 'input'"

The Answer for me was wrong spelling of ngModel. I had it written like this : ngModule while it should be ngModel.

All other attempts obviously failed to resolve the error for me.

How to create/make rounded corner buttons in WPF?

As alternative, you can code something like this:

    <Border 
            x:Name="borderBtnAdd"
            BorderThickness="1" 
            BorderBrush="DarkGray" 
            CornerRadius="360" 
            Height="30" 
            Margin="0,10,10,0" 
            VerticalAlignment="Top" HorizontalAlignment="Right" Width="30">
        <Image x:Name="btnAdd"
               Source="Recursos/Images/ic_add_circle_outline_black_24dp_2x.png"
               Width="{Binding borderBtnAdd.Width}" Height="{Binding borderBtnAdd.Height}"/>
    </Border>

The "Button" will look something like this:

You could set any other content instead of the image.

React with ES7: Uncaught TypeError: Cannot read property 'state' of undefined

Make sure you're calling super() as the first thing in your constructor.

You should set this for setAuthorState method

class ManageAuthorPage extends Component {

  state = {
    author: { id: '', firstName: '', lastName: '' }
  };

  constructor(props) {
    super(props);
    this.handleAuthorChange = this.handleAuthorChange.bind(this);
  } 

  handleAuthorChange(event) {
    let {name: fieldName, value} = event.target;

    this.setState({
      [fieldName]: value
    });
  };

  render() {
    return (
      <AuthorForm
        author={this.state.author}
        onChange={this.handleAuthorChange}
      />
    );
  }
}

Another alternative based on arrow function:

class ManageAuthorPage extends Component {

  state = {
    author: { id: '', firstName: '', lastName: '' }
  };

  handleAuthorChange = (event) => {
    const {name: fieldName, value} = event.target;

    this.setState({
      [fieldName]: value
    });
  };

  render() {
    return (
      <AuthorForm
        author={this.state.author}
        onChange={this.handleAuthorChange}
      />
    );
  }
}

Post multipart request with Android SDK

You can you use GentleRequest, which is lightweight library for making http requests(DISCLAIMER: I am the author):

Connections connections = new HttpConnections();
Binary binary = new PacketsBinary(new 
BufferedInputStream(new FileInputStream(file)), 
   file.length());
//Content-Type is set to multipart/form-data; boundary= 
//{generated by multipart object}
MultipartForm multipart = new HttpMultipartForm(
    new HttpFormPart("user", "aplication/json", 
       new JSONObject().toString().getBytes()),
    new HttpFormPart("java", "java.png", "image/png", 
       binary.content()));
Response response = connections.response(new 
    PostRequest(url, multipart));
if (response.hasSuccessCode()) {
    byte[] raw = response.body().value();
    String string = response.body().stringValue();
    JSONOBject json = response.body().jsonValue();
 } else {

 }

Feel free to check it out: https://github.com/Iprogrammerr/Gentle-Request

Warning: Null value is eliminated by an aggregate or other SET operation in Aqua Data Studio

If any Null value exists inside aggregate function you will face this issue. Instead of below code

 SELECT Count(closed)
  FROM   ticket
  WHERE  assigned_to = c.user_id
  AND closed IS NULL

use like

SELECT Count(ISNULL(closed, 0))
  FROM   ticket
  WHERE  assigned_to = c.user_id
  AND closed IS NULL

The Response content must be a string or object implementing __toString(), "boolean" given after move to psql

TL;DR

Just returning response()->json($promotion) won't solve the issue in this question. $promotion is an Eloquent object, which Laravel will automatically json_encode for the response. The json encoding is failing because of the img property, which is a PHP stream resource, and cannot be encoded.

Details

Whatever you return from your controller, Laravel is going to attempt to convert to a string. When you return an object, the object's __toString() magic method will be invoked to make the conversion.

Therefore, when you just return $promotion from your controller action, Laravel is going to call __toString() on it to convert it to a string to display.

On the Model, __toString() calls toJson(), which returns the result of json_encode. Therefore, json_encode is returning false, meaning it is running into an error.

Your dd shows that your img attribute is a stream resource. json_encode cannot encode a resource, so this is probably causing the failure. You should add your img attribute to the $hidden property to remove it from the json_encode.

class Promotion extends Model
{
    protected $hidden = ['img'];

    // rest of class
}

Returning string from C function

word is on the stack and goes out of scope as soon as getStr() returns. You are invoking undefined behavior.

How do you make a div follow as you scroll?

A better JQuery answer would be:

$('#ParentContainer').scroll(function() { 
    $('#FixedDiv').animate({top:$(this).scrollTop()});
});

You can also add a number after scrollTop i.e .scrollTop() + 5 to give it buff.

A good suggestion would also to limit the duration to 100 and go from default swing to linear easing.

$('#ParentContainer').scroll(function() { 
    $('#FixedDiv').animate({top:$(this).scrollTop()},100,"linear");
})

No such keg: /usr/local/Cellar/git

Had a similar issue while installing "Lua" in OS X using homebrew. I guess it could be useful for other users facing similar issue in homebrew.

On running the command:

$ brew install lua

The command returned an error:

Error: /usr/local/opt/lua is not a valid keg
(in general the error can be of /usr/local/opt/ is not a valid keg

FIXED it by deleting the file/directory it is referring to, i.e., deleting the "/usr/local/opt/lua" file.

root-user # rm -rf /usr/local/opt/lua

And then running the brew install command returned success.

PHP mkdir: Permission denied problem

I have this problem just now, my best solution I can give to you right now (despite that you didn't include any of your code) would be:

Check how you name your destination folder, eg: new_folder (sometimes this can cause error for permission as most hosts don't allow names using underscore, dash, etc to be created at run time). It worked for me.
If you were using recursive command to create sub-folders don't forget to put 0755 (remember to include 0 at the start) to the mkdir command, eg:
```
if(!file_exists($output)){
    if (!mkdir($output, 0755, true)) {//0755
        die('Failed to create folders...');
    }

}
```

This is also worked for me just now.

node.js execute system command synchronously

Node.js (since version 0.12 - so for a while) supports execSync:

child_process.execSync(command[, options])

You can now directly do this:

const execSync = require('child_process').execSync;
code = execSync('node -v');

and it'll do what you expect. (Defaults to pipe the i/o results to the parent process). Note that you can also spawnSync now.

Eclipse not recognizing JVM 1.8

Echoing the answer, above, a full install of the JDK (8u121 at this writing) from here - http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html - did the trick. Updating via the Mac OS Control Panel did not update the profile variable. Installing via the full installer, did. Then Eclipse was happy.

Warning: push.default is unset; its implicit value is changing in Git 2.0

I was wondering why I was getting that big warning message on Ubuntu 16.04 (which comes with Git 2.7.4), but not on Arch Linux. The reason is that the warning was removed in Git 2.8 (March 2016):

Across the transition at around Git version 2.0, the user used to get a pretty loud warning when running "git push" without setting push.default configuration variable. We no longer warn because the transition was completed a long time ago.

So you won't see the warning if you have Git 2.8 and later and don't need to set push.default unless you want to change the default 'simple' behavior.

Protecting cells in Excel but allow these to be modified by VBA script

As a workaround, you can create a hidden worksheet, which would hold the changed value. The cell on the visible, protected worksheet should display the value from the hidden worksheet using a simple formula.

You will be able to change the displayed value through the hidden worksheet, while your users won't be able to edit it.

how to set windows service username and password through commandline

In PowerShell, the "sc" command is an alias for the Set-Content cmdlet. You can workaround this using the following syntax:

sc.exe config Service obj= user password= pass

Specyfying the .exe extension, PowerShell bypasses the alias lookup.

HTH

Python: Importing urllib.quote

Use six:

from six.moves.urllib.parse import quote

six will simplify compatibility problems between Python 2 and Python 3, such as different import paths.

How to create timer in angular2

Found a npm package that makes this easy with RxJS as a service.

https://www.npmjs.com/package/ng2-simple-timer

You can 'subscribe' to an existing timer so you don't create a bazillion timers if you're using it many times in the same component.

Change type of varchar field to integer: "cannot be cast automatically to type integer"

You can do it like:

change_column :table_name, :column_name, 'integer USING CAST(column_name AS integer)'

or try this:

change_column :table_name, :column_name, :integer, using: 'column_name::integer'

If you are interested to find more about this topic read this article: https://kolosek.com/rails-change-database-column

Ruby on Rails: how to render a string as HTML?

If you're on rails which utilizes Erubis — the coolest way to do it is

<%== @str >

Note the double equal sign. See related question on SO for more info.

Hibernate vs JPA vs JDO - pros and cons of each?

Which would you suggest for a new project?

I would suggest neither! Use Spring DAO's JdbcTemplate together with StoredProcedure, RowMapper and RowCallbackHandler instead.

My own personal experience with Hibernate is that the time saved up-front is more than offset by the endless days you will spend down the line trying to understand and debug issues like unexpected cascading update behaviour.

If you are using a relational DB then the closer your code is to it, the more control you have. Spring's DAO layer allows fine control of the mapping layer, whilst removing the need for boilerplate code. Also, it integrates into Spring's transaction layer which means you can very easily add (via AOP) complicated transactional behaviour without this intruding into your code (of course, you get this with Hibernate too).

R Not in subset

The expression df1$id %in% idNums1 produces a logical vector. To negate it, you need to negate the whole vector:

!(df1$id %in% idNums1)

jQuery / Javascript code check, if not undefined

$.fn.attr(attributeName) returns the attribute value as string, or undefined when the attribute is not present.

Since "", and undefined are both falsy (evaluates to false when coerced to boolean) values in JavaScript, in this case I would write the check as below:

if (wlocation) { ... }

What's the key difference between HTML 4 and HTML 5?

You'll want to check HTML5 Differences from HTML4: W3C Working Group Note 9 December 2014 for the complete differences. There are many new elements and element attributes. Some elements were removed and others have different semantic value than before.

There are also APIs defined, such as the use of canvas, to help build the next generation of web apps and make sure implementations are standardized.

What's the difference between jquery.js and jquery.min.js?

jquery.js = Pretty and easy to read :) Read this one.
jquery.min.js = Looks like jibberish! But has a smaller file size. Put this one on your site.

Both are the same in functionality. The difference is only in whether it's formatted nicely for readability or compactly for smaller file size.

Specifically, the second one is minified, a process which involves removing unnecessary whitespace and shortening variable names. Both contribute to making the code much harder to read: the removal of whitespace removes line breaks and spaces messing up the formatting, and the shortening of variable names (including some function names) replaces the original variable names with meaningless letters.

All this is done in such a way that it doesn't affect the way the code behaves when run, in any way. Notably, the replacement/shortening of variable and function names is only done to names that appear in a local scope where it won't interfere with any other code in other scripts.

Up, Down, Left and Right arrow keys do not trigger KeyDown event

I had a similar issue when calling the WPF window out of WinForms.

var wpfwindow = new ScreenBoardWPF.IzbiraProjekti();
    ElementHost.EnableModelessKeyboardInterop(wpfwindow);
    wpfwindow.Show();

However, showing window as a dialog, it worked

var wpfwindow = new ScreenBoardWPF.IzbiraProjekti();
    ElementHost.EnableModelessKeyboardInterop(wpfwindow);
    wpfwindow.ShowDialog();

Hope this helps.

Flutter does not find android sdk

Choose the folder to install (I called it BASE_PATH) and use the following commands to install SDK with flutter:

Install SDK

cd $BASE_DIR
mkdir android-sdk
cd android-sdk
wget https://dl.google.com/android/repository/commandlinetools-linux-6200805_latest.zip
unzip commandlinetools-linux-6200805_latest.zip
./tools/bin/sdkmanager --sdk_root=$(pwd) "build-tools;28.0.3" "emulator" "platform-tools" "platforms;android-28" "tools"

I used a separate folder for SDK, because it will add parent folders.

Install Flutter

cd $BASE_DIR
wget https://storage.googleapis.com/flutter_infra/releases/stable/linux/flutter_linux_v1.12.13+hotfix.8-stable.tar.xz
tar xvf flutter_linux_v1.12.13+hotfix.8-stable.tar.xz

Export Vars (you can add them to your .bashrc)

export ANDROID_SDK=$BASE_DIR/android-sdk
export ANDROID_PATH=$ANDROID_SDK/tools:$ANDROID_SDK/platform-tools
export FLUTTER=$BASE_DIR/bin
export PATH=$PATH:$ANDROID_PATH:$FLUTTER

Check!

flutter doctor

Doctor summary (to see all details, run flutter doctor -v):
[?] Flutter (Channel beta, v1.12.13, on Linux, locale en_US.UTF-8)
[?] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[!] Android Studio (not installed)
[?] VS Code (version 1.31.1)
[!] Connected device
    ! No devices available

! Doctor found issues in 2 categories.

How do I write a bash script to restart a process if it dies?

I've used the following script with great success on numerous servers:

pid=`jps -v | grep $INSTALLATION | awk '{print $1}'`
echo $INSTALLATION found at PID $pid 
while [ -e /proc/$pid ]; do sleep 0.1; done

notes:

It's looking for a java process, so I can use jps, this is much more consistent across distributions than ps
$INSTALLATION contains enough of the process path that's it's totally unambiguous
Use sleep while waiting for the process to die, avoid hogging resources :)

This script is actually used to shut down a running instance of tomcat, which I want to shut down (and wait for) at the command line, so launching it as a child process simply isn't an option for me.

Kotlin unresolved reference in IntelliJ

Your Intellij IDEA plugin and the Kotlin runtime/compiler that you use in the project need to match. For example if IDE plugin is Beta 1, but your Gradle/Maven project using M12, you'll have issues exactly as you described. So check that everything lines up.

If you still have issues, with some older plugins you need to clear the caches in Intellij IDEA (file menu, Clear Caches and Restart, select option to restart).

What's the difference between JavaScript and JScript?

JScript is Microsoft's equivalent of JavaScript.
Java is an Oracle product and used to be a Sun product.

Oracle bought Sun.

JavaScript + Microsoft = JScript

Converting a view to Bitmap without displaying it in Android?

Hope this helps

View view="some view instance";        
view.setDrawingCacheEnabled(true);
Bitmap bitmap=view.getDrawingCache();
view.setDrawingCacheEnabled(false);

Update
getDrawingCache() method is deprecated in API level 28. So look for other alternative for API level > 28.

How can I write a heredoc to a file in Bash script?

I like this method for concision, readability and presentation in an indented script:

<<-End_of_file >file
?       foo bar
End_of_file

Where ? is a tab character.

SQL Server - find nth occurrence in a string

You can use the same function inside for the position +1

charindex('_', [TEXT], (charindex('_', [TEXT], 1))+1)

in where +1 is the nth time you will want to find.

What happens to a declared, uninitialized variable in C? Does it have a value?

That depends. If that definition is global (outside any function) then num will be initialized to zero. If it's local (inside a function) then its value is indeterminate. In theory, even attempting to read the value has undefined behavior -- C allows for the possibility of bits that don't contribute to the value, but have to be set in specific ways for you to even get defined results from reading the variable.

Java Regex Replace with Capturing Group

earl's answer gives you the solution, but I thought I'd add what the problem is that's causing your IllegalStateException. You're calling group(1) without having first called a matching operation (such as find()). This isn't needed if you're just using $1 since the replaceAll() is the matching operation.

ASP.NET MVC Bundle not rendering script files on staging server. It works on development server

Based on your comments, we need to go over how the Bundling mechanism works in MVC.

Edit: Based on the comment below by VSDev, you need to ensure WebGrease is installed into your project. NuGet would be the easiest was to install this package.

When you set a bundle configuration (Example not from above to illustrate)

bundles.Add(new ScriptBundle("~/bundles/mainJs")
      .Include("~/Scripts/mainSite.js")
      .Include("~/Scripts/helperStuff.js");

You then, in your views, call something like @Scripts.Render("~/bundles/mainJs"). When your web.config is set into a debug compilation OR you explicitly turn off bundling using the following line in your BundleConfig.cs file

BundleTable.EnableOptimizations = false;

Then, in your view, you will see the following rendered out

<script src="/Scripts/mainSite.js" type="text/javascript"></script>
<script src="/Scripts/helperStuff.js" type="text/javascript"></script>

These are the individual items that made up our bundle, uncompressed and listed individually. The reason these list out individually in debug mode is so that you can debug your scripts and see them as you wrote them (actual variable names, etc).

Now, when we are not in a debug compilation and have not turned off the EnableOptimizations feature, MVC will combine those files in our bundles, compress (minify) them and output only a single script tag.

<script src="/bundles/mainJs?v=someBigLongNumber" type="text/javascript"></script>

Notice that the source is the same as the name of the bundle from the bundle configurations. Also, the number after the ?v= will change anytime you change a file in that bundle. This is to help prevent caching of old js and css files by the client browsers.

Your scripts are still there and being outputted, but they are being compressed and combined into a single file called /bundles/mainJs. This feature is present to

A) compress the files and reduce information being transmitted and,

B) reduce the number of calls to a website to retrieve the necessary content to render the page.

Nothing is missing, it sounds like everything is working as intended. In a production site, the minification makes these files almost impossible to read, thus why the minification does not take affect while debugging.

As to why the jQuery UI is still being a single JS file, ensure someone didn't hard code that into your layout view. As for the JS errors, it could be errors that are present on your development box or perhaps something did not compress correctly (however, in all of my MVC development, I have not seen a JS error because of bad minification).

How do I change the title of the "back" button on a Navigation Bar

Maybe I'm being over simplistic but From Apple's documentation the wording is:

If a custom bar button item is not specified by either of the view controllers, a default back button is used and its title is set to the value of the title property of the previous view controller—that is, the view controller one level down on the stack.

The solution marked correct above sets a default button item from the parent controller. It's the right answer, but I'm solving the issue by changing self.title property of the UIViewController right before pushing the new controller onto the NavigationController stack.

This automatically updates the back button's title on the next controller, and as long as you set self.title back to what it should be in viewWillAppear I can't see this method causing too many problems.

How can I add an item to a IEnumerable<T> collection?

The code below solved my problem.

material.MaterialCasualties = material.MaterialCasualties.Append(materialCasualties).ToList();

customCustomer.CustomCustomerPayments = customCustomer.CustomCustomerPayments.Concat(customCustomerPayment).ToList();

Why am I getting an error "Object literal may only specify known properties"?

As of TypeScript 1.6, properties in object literals that do not have a corresponding property in the type they're being assigned to are flagged as errors.

Usually this error means you have a bug (typically a typo) in your code, or in the definition file. The right fix in this case would be to fix the typo. In the question, the property callbackOnLoactionHash is incorrect and should have been callbackOnLocationHash (note the mis-spelling of "Location").

This change also required some updates in definition files, so you should get the latest version of the .d.ts for any libraries you're using.

Example:

interface TextOptions {
    alignment?: string;
    color?: string;
    padding?: number;
}
function drawText(opts: TextOptions) { ... }
drawText({ align: 'center' }); // Error, no property 'align' in 'TextOptions'

But I meant to do that

There are a few cases where you may have intended to have extra properties in your object. Depending on what you're doing, there are several appropriate fixes

Type-checking only some properties

Sometimes you want to make sure a few things are present and of the correct type, but intend to have extra properties for whatever reason. Type assertions (<T>v or v as T) do not check for extra properties, so you can use them in place of a type annotation:

interface Options {
    x?: string;
    y?: number;
}

// Error, no property 'z' in 'Options'
let q1: Options = { x: 'foo', y: 32, z: 100 };
// OK
let q2 = { x: 'foo', y: 32, z: 100 } as Options;
// Still an error (good):
let q3 = { x: 100, y: 32, z: 100 } as Options;

These properties and maybe more

Some APIs take an object and dynamically iterate over its keys, but have 'special' keys that need to be of a certain type. Adding a string indexer to the type will disable extra property checking

Before

interface Model {
  name: string;
}
function createModel(x: Model) { ... }

// Error
createModel({name: 'hello', length: 100});

After

interface Model {
  name: string;
  [others: string]: any;
}
function createModel(x: Model) { ... }

// OK
createModel({name: 'hello', length: 100});

This is a dog or a cat or a horse, not sure yet

interface Animal { move; }
interface Dog extends Animal { woof; }
interface Cat extends Animal { meow; }
interface Horse extends Animal { neigh; }

let x: Animal;
if(...) {
  x = { move: 'doggy paddle', woof: 'bark' };
} else if(...) {
  x = { move: 'catwalk', meow: 'mrar' };
} else {
  x = { move: 'gallop', neigh: 'wilbur' };
}

Two good solutions come to mind here

Specify a closed set for x

// Removes all errors
let x: Dog|Cat|Horse;

or Type assert each thing

// For each initialization
  x = { move: 'doggy paddle', woof: 'bark' } as Dog;

This type is sometimes open and sometimes not

A clean solution to the "data model" problem using intersection types:

interface DataModelOptions {
  name?: string;
  id?: number;
}
interface UserProperties {
  [key: string]: any;
}
function createDataModel(model: DataModelOptions & UserProperties) {
 /* ... */
}
// findDataModel can only look up by name or id
function findDataModel(model: DataModelOptions) {
 /* ... */
}
// OK
createDataModel({name: 'my model', favoriteAnimal: 'cat' });
// Error, 'ID' is not correct (should be 'id')
findDataModel({ ID: 32 });

Can't find out where does a node.js app running and can't kill it

I use fkill

INSTALL

npm i fkill-cli -g

EXAMPLES

Search process in command line

fkill

OR: kill ! ALL process

fkill node

OR: kill process using port 8080

fkill :8080

Can you change what a symlink points to after it is created?

Yes, you can!

$ ln -sfn source_file_or_directory_name softlink_name

How to perform string interpolation in TypeScript?

Just use special `

var lyrics = 'Never gonna give you up';
var html = `<div>${lyrics}</div>`;

You can see more examples here.

How to check if a line is blank using regex

Full credit to bchr02 for this answer. However, I had to modify it a bit to catch the scenario for lines that have */ (end of comment) followed by an empty line. The regex was matching the non empty line with */.

New: (^(\r\n|\n|\r)$)|(^(\r\n|\n|\r))|^\s*$/gm

All I did is add ^ as second character to signify the start of line.

jQuery - Add active class and remove active from other element on click

Try this one:

$(document).ready(function() {
    $(".tab").click(function () {
        $("this").addClass("active").siblings().removeClass("active");   
    });
});

How to declare a constant in Java

Anything that is static is in the class level. You don't have to create instance to access static fields/method. Static variable will be created once when class is loaded.

Instance variables are the variable associated with the object which means that instance variables are created for each object you create. All objects will have separate copy of instance variable for themselves.

In your case, when you declared it as static final, that is only one copy of variable. If you change it from multiple instance, the same variable would be updated (however, you have final variable so it cannot be updated).

In second case, the final int a is also constant , however it is created every time you create an instance of the class where that variable is declared.

Have a look on this Java tutorial for better understanding ,

Send Email to multiple Recipients with MailMessage?

As suggested by Adam Miller in the comments, I'll add another solution.

The MailMessage(String from, String to) constructor accepts a comma separated list of addresses. So if you happen to have already a comma (',') separated list, the usage is as simple as:

MailMessage Msg = new MailMessage(fromMail, addresses);

In this particular case, we can replace the ';' for ',' and still make use of the constructor.

MailMessage Msg = new MailMessage(fromMail, addresses.replace(";", ","));

Whether you prefer this or the accepted answer it's up to you. Arguably the loop makes the intent clearer, but this is shorter and not obscure. But should you already have a comma separated list, I think this is the way to go.

how to install Lex and Yacc in Ubuntu?

Use the synaptic packet manager in order to install yacc / lex. If you are feeling more comfortable doing this on the console just do:

sudo apt-get install bison flex

There are some very nice articles on the net on how to get started with those tools. I found the article from CodeProject to be quite good and helpful (see here). But you should just try and search for "introduction to lex", there are plenty of good articles showing up.

What is console.log?

You use it to debug JavaScript code with either Firebug for Firefox, or JavaScript console in WebKit browsers.

var variable;

console.log(variable);

It will display the contents of the variable, even if it is a array or object.

It is similar to print_r($var); for PHP.

How to get AIC from Conway–Maxwell-Poisson regression via COM-poisson package in R?

I figured out myself.

cmp calls ComputeBetasAndNuHat which returns a list which has objective as minusloglik

So I can change the function cmp to get this value.

Error : java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.<init>(I)V

Update your pom.xml

<dependency>
  <groupId>asm</groupId>
  <artifactId>asm</artifactId>
  <version>3.1</version>
</dependency>

loading json data from local file into React JS

You are opening an asynchronous connection, yet you have written your code as if it was synchronous. The reqListener callback function will not execute synchronously with your code (that is, before React.createClass), but only after your entire snippet has run, and the response has been received from your remote location.

Unless you are on a zero-latency quantum-entanglement connection, this is well after all your statements have run. For example, to log the received data, you would:

function reqListener(e) {
    data = JSON.parse(this.responseText);
    console.log(data);
}

I'm not seeing the use of data in the React component, so I can only suggest this theoretically: why not update your component in the callback?

Trying to read cell 1,1 in spreadsheet using Google Script API

You have to first obtain the Range object. Also, getCell() will not return the value of the cell but instead will return a Range object of the cell. So, use something on the lines of

function email() {

// Opens SS by its ID

var ss = SpreadsheetApp.openById("0AgJjDgtUl5KddE5rR01NSFcxYTRnUHBCQ0stTXNMenc");

// Get the name of this SS

var name = ss.getName();  // Not necessary 

// Read cell 1,1 * Line below does't work *

// var data = Range.getCell(0, 0);
var sheet = ss.getSheetByName('Sheet1'); // or whatever is the name of the sheet 
var range = sheet.getRange(1,1); 
var data = range.getValue();

}

The hierarchy is Spreadsheet --> Sheet --> Range --> Cell.

Paging with Oracle

Ask Tom on pagination and very, very useful analytic functions.

This is excerpt from that page:

select * from (
    select /*+ first_rows(25) */
     object_id,object_name,
     row_number() over
    (order by object_id) rn
    from all_objects
)
where rn between :n and :m
order by rn;

Segmentation fault on large array sizes

Also, if you are running in most UNIX & Linux systems you can temporarily increase the stack size by the following command:

ulimit -s unlimited

But be careful, memory is a limited resource and with great power come great responsibilities :)

Local dependency in package.json

It is now possible to specify local Node module installation paths in your package.json directly. From the docs:

Local Paths

As of version 2.0.0 you can provide a path to a local directory that contains a package. Local paths can be saved using npm install -S or npm install --save, using any of these forms:
../foo/bar
~/foo/bar
./foo/bar
/foo/bar
in which case they will be normalized to a relative path and added to your package.json. For example:
{
  "name": "baz",
  "dependencies": {
    "bar": "file:../foo/bar"
  }
}
This feature is helpful for local offline development and creating tests that require npm installing where you don't want to hit an external server, but should not be used when publishing packages to the public registry.

Failed to add the host to the list of know hosts

Shouldn't known_hosts be a flat file, not a directory?

If that's not the problem, then this page on Github might be of some help. Try using SSH with the -v or -vv flag to see verbose error messages. It might give you a better idea of what's failing.

How to install SQL Server Management Studio 2008 component only

The accepted answer was correct up until July 2011. To get the latest version, including the Service Pack you should find the latest version as described here:

http://support.microsoft.com/kb/2527041

For example, if you check the SP2 CTP and SP1, you'll find the latest version of SQL Server Management Studio under SP1:

http://www.microsoft.com/en-us/download/details.aspx?id=26727

Download the 32-bit (x86) or 64-bit (x64) version of the SQLManagementStudio*.exe files as appropriate and install it. You can find out whether your system is 32-bit or 64-bit by right clicking Computer, selecting Properties and looking at the System Type.

Although you could apply the service pack to the base version that results from following the accepted answer, it's easier to just download the latest version of SQL Server Management Studio and simply install it in one step.

syntax error when using command line in python

Running from the command line means running from the terminal or DOS shell. You are running it from Python itself.

How can we redirect a Java program console output to multiple files?

Go to run as and choose Run Configurations -> Common and in the Standard Input and Output you can choose a File also.

Getting net::ERR_UNKNOWN_URL_SCHEME while calling telephone number from HTML page in Android

I had this issue occurring with mailto: and tel: links inside an iframe (in Chrome, not a webview). Clicking the links would show the grey "page not found" page and inspecting the page showed it had a ERR_UNKNOWN_URL_SCHEME error.

Adding target="_blank", as suggested by this discussion of the issue fixed the problem for me.

Using external images for CSS custom cursors

I would put this as a comment, but I don't have the rep for it. What Josh Crozier answered is correct, but for IE .cur and .ani are the only supported formats for this. So you should probably have a fallback just in case:

.test {
    cursor:url("http://www.javascriptkit.com/dhtmltutors/cursor-hand.gif"), url(foo.cur), auto;
}

Does a foreign key automatically create an index?

SQL Server autocreates indices for Primary Keys, but not for Foreign Keys. Create the index for the Foreign Keys. It's probably worth the overhead.

dyld: Library not loaded: /usr/local/lib/libpng16.16.dylib with anything php related

I had this error that wasn't solved by brew update && brew upgrade. For some reason I needed to install it from scratch:

$ brew install libpng

How to make a GUI for bash scripts?

If you want to write a graphical UI in bash, zenity is the way to go. This is what you can do with it:

Application Options:
  --calendar                                     Display calendar dialog
  --entry                                        Display text entry dialog
  --error                                        Display error dialog
  --info                                         Display info dialog
  --file-selection                               Display file selection dialog
  --list                                         Display list dialog
  --notification                                 Display notification
  --progress                                     Display progress indication dialog
  --question                                     Display question dialog
  --warning                                      Display warning dialog
  --scale                                        Display scale dialog
  --text-info                                    Display text information dialog

Combining these widgets you can create pretty usable GUIs. Of course, it's not as flexible as a toolkit integrated into a programming language, but in some cases it's really useful.

Best practice when adding whitespace in JSX

I have been trying to think of a good convention to use when placing text next to components on different lines, and found a couple good options:

<p>
    Hello {
        <span>World</span>
    }!
</p>

<p>
    Hello {}
    <span>World</span>
    {} again!
</p>

Each of these produces clean html without additional   or other extraneous markup. It creates fewer text nodes than using {' '}, and allows using of html entities where {' hello & goodbye '} does not.

How to merge a Series and DataFrame

If I could suggest setting up your dataframes like this (auto-indexing):

df = pd.DataFrame({'a':[np.nan, 1, 2], 'b':[4, 5, 6]})

then you can set up your s1 and s2 values thus (using shape() to return the number of rows from df):

s = pd.DataFrame({'s1':[5]*df.shape[0], 's2':[6]*df.shape[0]})

then the result you want is easy:

display (df.merge(s, left_index=True, right_index=True))

Alternatively, just add the new values to your dataframe df:

df = pd.DataFrame({'a':[nan, 1, 2], 'b':[4, 5, 6]})
df['s1']=5
df['s2']=6
display(df)

Both return:

     a  b  s1  s2
0  NaN  4   5   6
1  1.0  5   5   6
2  2.0  6   5   6

If you have another list of data (instead of just a single value to apply), and you know it is in the same sequence as df, eg:

s1=['a','b','c']

then you can attach this in the same way:

df['s1']=s1

returns:

     a  b s1
0  NaN  4  a
1  1.0  5  b
2  2.0  6  c

Git checkout: updating paths is incompatible with switching branches

Could your issue be linked to this other SO question "checkout problem"?

i.e.: a problem related to:

an old version of Git
a curious checkout syntax, which should be: git checkout -b [<new_branch>] [<start_point>], with [<start_point>] referring to the name of a commit at which to start the new branch, and 'origin/remote-name' is not that.
(whereas git branch does support a start_point being the name of a remote branch)

Note: what the checkout.sh script says is:

  if test '' != "$newbranch$force$merge"
  then
    die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
  fi

It is like the syntax git checkout -b [] [remote_branch_name] was both renaming the branch and resetting the new starting point of the new branch, which is deemed incompatible.

How to use GOOGLEFINANCE(("CURRENCY:EURAUD")) function

Some currency pairs have no historical data for certain days.

Compare =GOOGLEFINANCE("CURRENCY:EURNOK", "close", DATE(2016,1,1), DATE(2016,1,12):

Date                Close
1/1/2016 23:58:00   9.6248922
1/2/2016 23:58:00   9.632922114
1/3/2016 23:58:00   9.579957264
1/4/2016 23:58:00   9.609146435
1/5/2016 23:58:00   9.573877808
1/6/2016 23:58:00   9.639368875
1/7/2016 23:58:00   9.707103569
1/8/2016 23:58:00   9.673324479
1/9/2016 23:58:00   9.702379872
1/10/2016 23:58:00  9.702721875
1/11/2016 23:58:00  9.705679083

and =GOOGLEFINANCE("CURRENCY:EURRUB", "close", DATE(2016,1,1), DATE(2016,1,12):

Date                Close
1/1/2016 23:58:00   79.44402768
1/4/2016 23:58:00   79.14048175
1/5/2016 23:58:00   80.0452446
1/6/2016 23:58:00   80.3761125
1/7/2016 23:58:00   81.70830185
1/8/2016 23:58:00   81.70680013
1/11/2016 23:58:00  82.50853122

So, =INDEX(GOOGLEFINANCE("CURRENCY:EURRUB", "close", DATE(2016,1,1)), 2, 2) gives

79.44402768

But =INDEX(GOOGLEFINANCE("CURRENCY:EURRUB", "close", DATE(2016,1,2)), 2, 2) gives

#N/A

Therefore, when working with currency pairs that have no exchange rates for weekends/holidays, the following formula may be used for getting the exchange rate for the first following working day:

=INDEX(GOOGLEFINANCE("CURRENCY:EURRUB", "close", DATE(2016,1,2), 4), 2, 2)

In Bash, how to add "Are you sure [Y/n]" to any command or alias?

read -r -p "Are you sure? [Y/n]" response
  response=${response,,} # tolower
  if [[ $response =~ ^(yes|y| ) ]] || [[ -z $response ]]; then
      your-action-here
  fi

Modifying local variable from inside lambda

If you only need to pass the value from the outside into the lambda, and not get it out, you can do it with a regular anonymous class instead of a lambda:

list.forEach(new Consumer<Example>() {
    int ordinal = 0;
    public void accept(Example s) {
        s.setOrdinal(ordinal);
        ordinal++;
    }
});

How to convert column with dtype as object to string in Pandas Dataframe

Not answering the question directly, but it might help someone else.

I have a column called Volume, having both - (invalid/NaN) and numbers formatted with ,

df['Volume'] = df['Volume'].astype('str')
df['Volume'] = df['Volume'].str.replace(',', '')
df['Volume'] = pd.to_numeric(df['Volume'], errors='coerce')

Casting to string is required for it to apply to str.replace

pandas.Series.str.replace
pandas.to_numeric

HTML5 event handling(onfocus and onfocusout) using angular 2

<input name="date" type="text" (focus)="focusFunction()" (focusout)="focusOutFunction()">

works for me from Pardeep Jain

How to get the innerHTML of selectable jquery element?

$(function() {
        $("#select-image").selectable({
            selected: function( event, ui ) { 
                var $variable = $('.ui-selected').html(); 
                console.log($variable);
            }
        });
    });

$(function() {
        $("#select-image").selectable({
            selected: function( event, ui ) { 
                var $variable = $('.ui-selected').text(); 
                console.log($variable);
            }
        });
    });

$(function() {
        $("#select-image").selectable({
            selected: function( event, ui ) { 
                var $variable = $('.ui-selected').val(); 
                console.log($variable);
            }
        });
    });

Simple proof that GUID is not unique

A GUID is theoretically non-unique. Here's your proof:

GUID is a 128 bit number
You cannot generate 2^128 + 1 or more GUIDs without re-using old GUIDs

However, if the entire power output of the sun was directed at performing this task, it would go cold long before it finished.

GUIDs can be generated using a number of different tactics, some of which take special measures to guarantee that a given machine will not generate the same GUID twice. Finding collisions in a particular algorithm would show that your particular method for generating GUIDs is bad, but would not prove anything about GUIDs in general.

Remove all html tags from php string

<?php $data = "<div><p>Welcome to my PHP class, we are glad you are here</p></div>"; echo strip_tags($data); ?>

Or if you have a content coming from the database;

<?php $data = strip_tags($get_row['description']); ?> <?=substr($data, 0, 100) ?><?php if(strlen($data) > 100) { ?>...<?php } ?>

SQL Inner join more than two tables

The right syntax is like:

SELECT * FROM table1 INNER JOIN table2 ON table1.primaryKey = table2.ForeignKey
INNER JOIN table3 ON table3.primaryKey = table2.ForeignKey

Orthe last line joining table3 on table1 like:

ON table3.ForeignKey= table1.PrimaryKey

Insecure content in iframe on secure page

Based on generality of this question, I think, that you'll need to setup your own HTTPS proxy on some server online. Do the following steps:

Prepare your proxy server - install IIS, Apache
Get valid SSL certificate to avoid security errors (free from startssl.com for example)
Write a wrapper, which will download insecure content (how to below)
From your site/app get https://yourproxy.com/?page=http://insecurepage.com

If you simply download remote site content via file_get_contents or similiar, you can still have insecure links to content. You'll have to find them with regex and also replace. Images are hard to solve, but Ï found workaround here: http://foundationphp.com/tutorials/image_proxy.php

Note: While this solution may have worked in some browsers when it was written in 2014, it no longer works. Navigating or redirecting to an HTTP URL in an iframe embedded in an HTTPS page is not permitted by modern browsers, even if the frame started out with an HTTPS URL.

The best solution I created is to simply use google as the ssl proxy...

https://www.google.com/search?q=%http://yourhttpsite.com&btnI=Im+Feeling+Lucky

Tested and works in firefox.

Other Methods:

Use a Third party such as embed.ly (but it it really only good for well known http APIs).
Create your own redirect script on an https page you control (a simple javascript redirect on a relative linked page should do the trick. Something like: (you can use any langauge/method)

https://example.com That has a iframe linking to...

https://example.com/utilities/redirect.html Which has a simple js redirect script like...

document.location.href ="http://thenonsslsite.com";
Alternatively, you could add an RSS feed or write some reader/parser to read the http site and display it within your https site.
You could/should also recommend to the http site owner that they create an ssl connection. If for no other reason than it increases seo.

Unless you can get the http site owner to create an ssl certificate, the most secure and permanent solution would be to create an RSS feed grabing the content you need (presumably you are not actually 'doing' anything on the http site -that is to say not logging in to any system).

The real issue is that having http elements inside a https site represents a security issue. There are no completely kosher ways around this security risk so the above are just current work arounds.

Note, that you can disable this security measure in most browsers (yourself, not for others). Also note that these 'hacks' may become obsolete over time.

Persist javascript variables across pages?

You could use the window’s name window.name to store the information. This is known as JavaScript session. But it only works as long as the same window/tab is used.

Find records with a date field in the last 24 hours

To get records from the last 24 hours:

SELECT * from [table_name] WHERE date > (NOW() - INTERVAL 24 HOUR)

How exactly does binary code get converted into letters?

Do you mean the conversion 011001100110111101101111 ? foo, for example? You just take the binary stream, split it into separate bytes (01100110, 01101111, 01101111) and look up the ASCII character that corresponds to given number. For example, 01100110 is 102 in decimal and the ASCII character with code 102 is f:

$ perl -E 'say 0b01100110'
102
$ perl -E 'say chr(102)'
f

(See what the chr function does.) You can generalize this algorithm and have a different number of bits per character and different encodings, the point remains the same.

What is more efficient? Using pow to square or just multiply it with itself?

I have been busy with a similar problem, and I'm quite puzzled by the results. I was calculating x?³/² for Newtonian gravitation in an n-bodies situation (acceleration undergone from another body of mass M situated at a distance vector d) : a = M G d*(d²)?³/² (where d² is the dot (scalar) product of d by itself) , and I thought calculating M*G*pow(d2, -1.5) would be simpler than M*G/d2/sqrt(d2)

The trick is that it is true for small systems, but as systems grow in size, M*G/d2/sqrt(d2) becomes more efficient and I don't understand why the size of the system impacts this result, because repeating the operation on different data does not. It is as if there were possible optimizations as the system grow, but which are not possible with pow

Search for string and get count in vi editor

(similar as Gustavo said, but additionally: )

For any previously search, you can do simply:

:%s///gn

A pattern is not needed, because it is already in the search-register (@/).

"%" - do s/ in the whole file
"g" - search global (with multiple hits in one line)
"n" - prevents any replacement of s/ -- nothing is deleted! nothing must be undone!
(see: :help s_flag for more informations)

(This way, it works perfectly with "Search for visually selected text", as described in vim-wikia tip171)

Convert 24 Hour time to 12 Hour plus AM/PM indication Oracle SQL

For the 24-hour time, you need to use HH24 instead of HH.

For the 12-hour time, the AM/PM indicator is written as A.M. (if you want periods in the result) or AM (if you don't). For example:

SELECT invoice_date,
       TO_CHAR(invoice_date, 'DD-MM-YYYY HH24:MI:SS') "Date 24Hr",
       TO_CHAR(invoice_date, 'DD-MM-YYYY HH:MI:SS AM') "Date 12Hr"
  FROM invoices
;

For more information on the format models you can use with TO_CHAR on a date, see http://docs.oracle.com/cd/E16655_01/server.121/e17750/ch4datetime.htm#NLSPG004.

Pandas: drop a level from a multi-level column index?

Another way to drop the index is to use a list comprehension:

df.columns = [col[1] for col in df.columns]

   b  c
0  1  2
1  3  4

This strategy is also useful if you want to combine the names from both levels like in the example below where the bottom level contains two 'y's:

cols = pd.MultiIndex.from_tuples([("A", "x"), ("A", "y"), ("B", "y")])
df = pd.DataFrame([[1,2, 8 ], [3,4, 9]], columns=cols)

   A     B
   x  y  y
0  1  2  8
1  3  4  9

Dropping the top level would leave two columns with the index 'y'. That can be avoided by joining the names with the list comprehension.

df.columns = ['_'.join(col) for col in df.columns]

    A_x A_y B_y
0   1   2   8
1   3   4   9

That's a problem I had after doing a groupby and it took a while to find this other question that solved it. I adapted that solution to the specific case here.

Error: macro names must be identifiers using #ifdef 0

Use the following to evaluate an expression (constant 0 evaluates to false).

#if 0
 ...
#endif

Android Endless List

Best solution so far that I have seen is in FastAdapter library for recycler views. It has a EndlessRecyclerOnScrollListener.

Here is an example usage: EndlessScrollListActivity

Once I used it for endless scrolling list I have realised that the setup is a very robust. I'd definitely recommend it.

difference between css height : 100% vs height : auto

height:100% works if the parent container has a specified height property else, it won't work

Spring Test & Security: How to mock authentication?

Since Spring 4.0+, the best solution is to annotate the test method with @WithMockUser

@Test
@WithMockUser(username = "user1", password = "pwd", roles = "USER")
public void mytest1() throws Exception {
    mockMvc.perform(get("/someApi"))
        .andExpect(status().isOk());
}

Remember to add the following dependency to your project

'org.springframework.security:spring-security-test:4.2.3.RELEASE'

Html code as IFRAME source rather than a URL

iframe srcdoc: This attribute contains HTML content, which will override src attribute. If a browser does not support the srcdoc attribute, it will fall back to the URL in the src attribute.

Let's understand it with an example

<iframe 
    name="my_iframe" 
    srcdoc="<h1 style='text-align:center; color:#9600fa'>Welcome to iframes</h1>"
    src="https://www.birthdaycalculatorbydate.com/"
    width="500px"
    height="200px"
></iframe>

Original content is taken from iframes.

Best practice to run Linux service as a different user

Why not try the following in the init script:

setuid $USER application_name

It worked for me.

Why can't I call a public method in another class?

For example 1 and 2 you need to create static methods:

public static string InstanceMethod() {return "Hello World";}

Then for example 3 you need an instance of your object to invoke the method:

object o = new object();
string s = o.InstanceMethod();

Understanding the Rails Authenticity Token

What happens

When the user views a form to create, update, or destroy a resource, the Rails app creates a random authenticity_token, stores this token in the session, and places it in a hidden field in the form. When the user submits the form, Rails looks for the authenticity_token, compares it to the one stored in the session, and if they match the request is allowed to continue.

Why it happens

Since the authenticity token is stored in the session, the client cannot know its value. This prevents people from submitting forms to a Rails app without viewing the form within that app itself. Imagine that you are using service A, you logged into the service and everything is ok. Now imagine that you went to use service B, and you saw a picture you like, and pressed on the picture to view a larger size of it. Now, if some evil code was there at service B, it might send a request to service A (which you are logged into), and ask to delete your account, by sending a request to http://serviceA.com/close_account. This is what is known as CSRF (Cross Site Request Forgery).

If service A is using authenticity tokens, this attack vector is no longer applicable, since the request from service B would not contain the correct authenticity token, and will not be allowed to continue.

API docs describes details about meta tag:

CSRF protection is turned on with the protect_from_forgery method, which checks the token and resets the session if it doesn't match what was expected. A call to this method is generated for new Rails applications by default. The token parameter is named authenticity_token by default. The name and value of this token must be added to every layout that renders forms by including csrf_meta_tags in the HTML head.

Notes

Keep in mind, Rails only verifies not idempotent methods (POST, PUT/PATCH and DELETE). GET request are not checked for authenticity token. Why? because the HTTP specification states that GET requests is idempotent and should not create, alter, or destroy resources at the server, and the request should be idempotent (if you run the same command multiple times, you should get the same result every time).

Also the real implementation is a bit more complicated as defined in the beginning, ensuring better security. Rails does not issue the same stored token with every form. Neither does it generate and store a different token every time. It generates and stores a cryptographic hash in a session and issues new cryptographic tokens, which can be matched against the stored one, every time a page is rendered. See request_forgery_protection.rb.

Lessons

Use authenticity_token to protect your not idempotent methods (POST, PUT/PATCH, and DELETE). Also make sure not to allow any GET requests that could potentially modify resources on the server.

EDIT: Check the comment by @erturne regarding GET requests being idempotent. He explains it in a better way than I have done here.

Split output of command by columns using Bash?

I think the simplest way is to use awk. Example:

$ echo "11383 pts/1    00:00:00 bash" | awk '{ print $4; }'
bash

What is %2C in a URL?

Another technique that you can use to get the symbol from url gibberish is to open Chrome console with F12 and just paste following javascript:

decodeURIComponent("%2c")

it will decode and return the symbol (or symbols).

Hope this saves you some time.

What is a .NET developer?

Though I consider myself a .NET developer, I don't prefer calling it that way. c# developer sounds much better and is a much clearer message: it says that I understand both C# and .NET (because C# and .NET are tied together). I could call myself a VB.NET developer, same story there.

What is a .NET developer? I don't know, because you cannot develop with .NET, if develop is a synonym for programming. .NET is the environment, the libraries, the languages, the CLR, the CLI, JIT, the LR, the BCL, the IDE and the IL. I find it a poor job description, but it may also mean that they don't really care: either you are an F#, a C#, an IronPython or a VB.NET developer, they're all implicitly and secretly .NET developers.

What do you need? A solid understanding why ".NET" is a poor job description and ask for a more precise one. Nobody can know everything of .NET, it is simply too wide. Orientate yourself to all sides of it and do both ASP.NET and WinForms. Don't forget Silverlight, WPF etc and two or three .NET languages.

In other words: know the forest by knowing what trees and flowers it habitats and specialize in knowing a few beautiful and common ones well.

How to change working directory in Jupyter Notebook?

It's simple, every time you open Jupyter Notebook and you are in your current work directory, open the Terminal in the near top right corner position where create new Python file in. The terminal in Jupyter will appear in the new tab. Type command cd <your new work directory> and enter, and then type Jupyter Notebook in that terminal, a new Jupyter Notebook will appear in the new tab with your new work directory.

Returning a promise in an async function in TypeScript

When you do new Promise((resolve)... the type inferred was Promise<{}> because you should have used new Promise<number>((resolve).

It is interesting that this issue was only highlighted when the async keyword was added. I would recommend reporting this issue to the TS team on GitHub.

There are many ways you can get around this issue. All the following functions have the same behavior:

const whatever1 = () => {
    return new Promise<number>((resolve) => {
        resolve(4);
    });
};

const whatever2 = async () => {
    return new Promise<number>((resolve) => {
        resolve(4);
    });
};

const whatever3 = async () => {
    return await new Promise<number>((resolve) => {
        resolve(4);
    });
};

const whatever4 = async () => {
    return Promise.resolve(4);
};

const whatever5 = async () => {
    return await Promise.resolve(4);
};

const whatever6 = async () => Promise.resolve(4);

const whatever7 = async () => await Promise.resolve(4);

In your IDE you will be able to see that the inferred type for all these functions is () => Promise<number>.

How do I split a string with multiple separators in JavaScript?

I use regexp:

str =  'Write a program that extracts from a given text all palindromes, e.g. "ABBA", "lamal", "exe".';

var strNew = str.match(/\w+/g);

// Output: ["Write", "a", "program", "that", "extracts", "from", "a", "given", "text", "all", "palindromes", "e", "g", "ABBA", "lamal", "exe"]

How to set recurring schedule for xlsm file using Windows Task Scheduler

Three important steps - How to Task Schedule an excel.xls(m) file

simply:

make sure the .vbs file is correct
set the Action tab correctly in Task Scheduler
don't turn on "Run whether user is logged on or not"

IN MORE DETAIL...

Here is an example .vbs file:

'   a .vbs file is just a text file containing visual basic code that has the extension renamed from .txt  to .vbs

'Write Excel.xls  Sheet's full path here
strPath = "C:\RodsData.xlsm" 

'Write the macro name - could try including module name
strMacro = "Update" '    "Sheet1.Macro2" 

'Create an Excel instance and set visibility of the instance
Set objApp = CreateObject("Excel.Application") 
objApp.Visible = True   '   or False 

'Open workbook; Run Macro; Save Workbook with changes; Close; Quit Excel
Set wbToRun = objApp.Workbooks.Open(strPath) 
objApp.Run strMacro     '   wbToRun.Name & "!" & strMacro 
wbToRun.Save 
wbToRun.Close 
objApp.Quit 

'Leaves an onscreen message!
MsgBox strPath & " " & strMacro & " macro and .vbs successfully completed!",         vbInformation 
'

In the Action tab (Task Scheduler):

set Program/script: = C:\Windows\System32\cscript.exe

set Add arguments (optional): = C:\MyVbsFile.vbs

Finally, don't turn on "Run whether user is logged on or not".

That should work.

Let me know!

Rod Bowen

How to find what code is run by a button or element in Chrome using Developer Tools

Alexander Pavlov's answer gets the closest to what you want.

Due to the extensiveness of jQuery's abstraction and functionality, a lot of hoops have to be jumped in order to get to the meat of the event. I have set up this jsFiddle to demonstrate the work.

1. Setting up the Event Listener Breakpoint

You were close on this one.

Open the Chrome Dev Tools (F12), and go to the Sources tab.
Drill down to Mouse -> Click

(click to zoom)

2. Click the button!

Chrome Dev Tools will pause script execution, and present you with this beautiful entanglement of minified code:

(click to zoom)

3. Find the glorious code!

Now, the trick here is to not get carried away pressing the key, and keep an eye out on the screen.

Press the F11 key (Step In) until desired source code appears
Source code finally reached
- In the jsFiddle sample provided above, I had to press F11 108 times before reaching the desired event handler/function
- Your mileage may vary, depending on the version of jQuery (or framework library) used to bind the events
- With enough dedication and time, you can find any event handler/function

4. Explanation

I don't have the exact answer, or explanation as to why jQuery goes through the many layers of abstractions it does - all I can suggest is that it is because of the job it does to abstract away its usage from the browser executing the code.

Here is a jsFiddle with a debug version of jQuery (i.e., not minified). When you look at the code on the first (non-minified) breakpoint, you can see that the code is handling many things:

    // ...snip...

    if ( !(eventHandle = elemData.handle) ) {
        eventHandle = elemData.handle = function( e ) {
            // Discard the second event of a jQuery.event.trigger() and
            // when an event is called after a page has unloaded
            return typeof jQuery !== strundefined && jQuery.event.triggered !== e.type ?
                jQuery.event.dispatch.apply( elem, arguments ) : undefined;
        };
    }

    // ...snip...

The reason I think you missed it on your attempt when the "execution pauses and I jump line by line", is because you may have used the "Step Over" function, instead of Step In. Here is a StackOverflow answer explaining the differences.

Finally, the reason why your function is not directly bound to the click event handler is because jQuery returns a function that gets bound. jQuery's function in turn goes through some abstraction layers and checks, and somewhere in there, it executes your function.

Case insensitive string as HashMap key

Instead of creating your own class to validate and store case insensitive string as a HashMap key, you can use:

LinkedCaseInsensitiveMap wraps a LinkedHashMap, which is a Map based on a hash table and a linked list. Unlike LinkedHashMap, it doesn't allow null key inserting. LinkedCaseInsensitiveMap preserves the original order as well as the original casing of keys while allowing calling functions like get and remove with any case.

Eg:

Map<String, Integer> linkedHashMap = new LinkedCaseInsensitiveMap<>();
linkedHashMap.put("abc", 1);
linkedHashMap.put("AbC", 2);

System.out.println(linkedHashMap);

Output: {AbC=2}

Mvn Dependency:

Spring Core is a Spring Framework module that also provides utility classes, including LinkedCaseInsensitiveMap.

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>5.2.5.RELEASE</version>
</dependency>

CaseInsensitiveMap is a hash-based Map, which converts keys to lower case before they are being added or retrieved. Unlike TreeMap, CaseInsensitiveMap allows null key inserting.

Eg:

Map<String, Integer> commonsHashMap = new CaseInsensitiveMap<>();
commonsHashMap.put("ABC", 1);
commonsHashMap.put("abc", 2);
commonsHashMap.put("aBc", 3);

System.out.println(commonsHashMap);

Output: {abc=3}

Dependency:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.4</version>
</dependency>

TreeMap is an implementation of NavigableMap, which means that it always sorts the entries after inserting, based on a given Comparator. Also, TreeMap uses a Comparator to find if an inserted key is a duplicate or a new one.

Therefore, if we provide a case-insensitive String Comparator, we'll get a case-insensitive TreeMap.

Eg:

Map<String, Integer> treeMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
treeMap.put("ABC", 1);
treeMap.put("ABc", 2);
treeMap.put("cde", 1);
        
System.out.println(treeMap);

Output: {ABC=2, cde=1}

downcast and upcast

Answer 1 : Yes it called upcasting but the way you do it is not modern way. Upcasting can be performed implicitly you don't need any conversion. So just writing Employee emp = mgr; is enough for upcasting.

Answer 2 : If you create object of Manager class we can say that manager is an employee. Because class Manager : Employee depicts Is-A relationship between Employee Class and Manager Class. So we can say that every manager is an employee.

But if we create object of Employee class we can not say that this employee is manager because class Employee is a class which is not inheriting any other class. So you can not directly downcast that Employee Class object to Manager Class object.

So answer is, if you want to downcast from Employee Class object to Manager Class object, first you must have object of Manager Class first then you can upcast it and then you can downcast it.

onclick event pass <li> id or value

Try this:

<li onclick="getPaging(this.id)" id="1">1</li>
<li onclick="getPaging(this.id)" id="2">2</li>


function getPaging(str)
{
    $("#loading-content").load("dataSearch.php?"+str, hideLoader);
}

SAP Crystal Reports runtime for .Net 4.0 (64-bit)

I have found a variety of runtimes including Visual Studio(VS) versions are available at http://scn.sap.com/docs/DOC-7824

jQuery: Check if button is clicked

$('#btn1, #btn2').click(function() {
    let clickedButton = $(this).attr('id');
    console.log(clickedButton);
});

Freeing up a TCP/IP port?

The "netstat --programs" command will give you the process information, assuming you're the root user. Then you will have to kill the "offending" process which may well start up again just to annoy you.

Depending on what you're actually trying to achieve, solutions to that problem will vary based on the processes holding those ports. For example, you may need to disable services (assuming they're unneeded) or configure them to use a different port (if you do need them but you need that port more).

Spring Boot without the web server

You can create something like this:

@SpringBootApplication
public class Application {
  public static void main(String[] args) {
    new SpringApplicationBuilder(Application.class).web(false).run(args);
  }
}

And

@Component
public class CommandLiner implements CommandLineRunner {

  @Override
  public void run(String... args) throws Exception {
    // Put your logic here
  }

}

The dependency is still there though but not used.

How do I debug error ECONNRESET in Node.js?

A simple tcp server I had for serving the flash policy file was causing this. I can now catch the error using a handler:

# serving the flash policy file
net = require("net")

net.createServer((socket) =>
  //just added
  socket.on("error", (err) =>
    console.log("Caught flash policy server socket error: ")
    console.log(err.stack)
  )

  socket.write("<?xml version=\"1.0\"?>\n")
  socket.write("<!DOCTYPE cross-domain-policy SYSTEM \"http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd\">\n")
  socket.write("<cross-domain-policy>\n")
  socket.write("<allow-access-from domain=\"*\" to-ports=\"*\"/>\n")
  socket.write("</cross-domain-policy>\n")
  socket.end()
).listen(843)

C# List<string> to string with delimiter

You can use String.Join. If you have a List<string> then you can call ToArray first:

List<string> names = new List<string>() { "John", "Anna", "Monica" };
var result = String.Join(", ", names.ToArray());

In .NET 4 you don't need the ToArray anymore, since there is an overload of String.Join that takes an IEnumerable<string>.

Results:

John, Anna, Monica

Method call if not null in C#

There is a little-known null operator in C# for this, ??. May be helpful:

http://weblogs.asp.net/scottgu/archive/2007/09/20/the-new-c-null-coalescing-operator-and-using-it-with-linq.aspx

What is the simplest C# function to parse a JSON string into an object?

I would echo the Json.NET library, which can transform the JSON response into a XML document. With the XML document, you can easily query with XPath and extract the data you need. I find this pretty useful.

How can I find my php.ini on wordpress?

The name of the custom ini file depends on the user_ini.filename php setting. By default this should be .user.ini and the custom configuration files are used on a per-directory basis, so you should be able to either put it in the root of your Wordpress installation or under the wp-admin folder.

You can check the name of your custom configuration file by running:

php -i | grep user_ini.filename

I have created a plugin which makes it possible to change php settings from the Wordpress administration:

Custom PHP Settings

The plugin makes it possible to change settings either using the .htaccess file or the custom php.ini file, depending on how php is running.

'tsc command not found' in compiling typescript

The only solution that work for me was put npx tsc -v or for the compiling npx tsc salida.ts

"salida.ts" is the name of the file

RVM is not a function, selecting rubies with 'rvm use ...' will not work

From a new Ubuntu 16.04 Installation

1) Terminal => Edit => Profile Preferences

2) Command Tab => Check Run command as a login shell

3) Close, and reopen terminal

rvm --default use 2.2.4

Javascript to sort contents of select element

This is a a recompilation of my 3 favorite answers on this board:

jOk's best and simplest answer.
Terry Porter's easy jQuery method.
SmokeyPHP's configurable function.

The results are an easy to use, and easily configurable function.

First argument can be a select object, the ID of a select object, or an array with at least 2 dimensions.

Second argument is optional. Defaults to sorting by option text, index 0. Can be passed any other index so sort on that. Can be passed 1, or the text "value", to sort by value.

Sort by text examples (all would sort by text):

 sortSelect('select_object_id');
 sortSelect('select_object_id', 0);
 sortSelect(selectObject);
 sortSelect(selectObject, 0);

Sort by value (all would sort by value):

 sortSelect('select_object_id', 'value');
 sortSelect('select_object_id', 1);
 sortSelect(selectObject, 1);

Sort any array by another index:

var myArray = [
  ['ignored0', 'ignored1', 'Z-sortme2'],
  ['ignored0', 'ignored1', 'A-sortme2'],
  ['ignored0', 'ignored1', 'C-sortme2'],
];

sortSelect(myArray,2);

This last one will sort the array by index-2, the sortme's.

Main sort function

function sortSelect(selElem, sortVal) {

    // Checks for an object or string. Uses string as ID. 
    switch(typeof selElem) {
        case "string":
            selElem = document.getElementById(selElem);
            break;
        case "object":
            if(selElem==null) return false;
            break;
        default:
            return false;
    }

    // Builds the options list.
    var tmpAry = new Array();
    for (var i=0;i<selElem.options.length;i++) {
        tmpAry[i] = new Array();
        tmpAry[i][0] = selElem.options[i].text;
        tmpAry[i][1] = selElem.options[i].value;
    }

    // allows sortVal to be optional, defaults to text.
    switch(sortVal) {
        case "value": // sort by value
            sortVal = 1;
            break;
        default: // sort by text
            sortVal = 0;
    }
    tmpAry.sort(function(a, b) {
        return a[sortVal] == b[sortVal] ? 0 : a[sortVal] < b[sortVal] ? -1 : 1;
    });

    // removes all options from the select.
    while (selElem.options.length > 0) {
        selElem.options[0] = null;
    }

    // recreates all options with the new order.
    for (var i=0;i<tmpAry.length;i++) {
        var op = new Option(tmpAry[i][0], tmpAry[i][1]);
        selElem.options[i] = op;
    }

    return true;
}

Pandas: create two new columns in a dataframe with values calculated from a pre-existing column

The top answer is flawed in my opinion. Hopefully, no one is mass importing all of pandas into their namespace with from pandas import *. Also, the map method should be reserved for those times when passing it a dictionary or Series. It can take a function but this is what apply is used for.

So, if you must use the above approach, I would write it like this

df["A1"], df["A2"] = zip(*df["a"].apply(calculate))

There's actually no reason to use zip here. You can simply do this:

df["A1"], df["A2"] = calculate(df['a'])

This second method is also much faster on larger DataFrames

df = pd.DataFrame({'a': [1,2,3] * 100000, 'b': [2,3,4] * 100000})

DataFrame created with 300,000 rows

%timeit df["A1"], df["A2"] = calculate(df['a'])
2.65 ms ± 92.4 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

%timeit df["A1"], df["A2"] = zip(*df["a"].apply(calculate))
159 ms ± 5.24 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

60x faster than zip

In general, avoid using apply

Apply is generally not much faster than iterating over a Python list. Let's test the performance of a for-loop to do the same thing as above

%%timeit
A1, A2 = [], []
for val in df['a']:
    A1.append(val**2)
    A2.append(val**3)

df['A1'] = A1
df['A2'] = A2

298 ms ± 7.14 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

So this is twice as slow which isn't a terrible performance regression, but if we cythonize the above, we get much better performance. Assuming, you are using ipython:

%load_ext cython

%%cython
cpdef power(vals):
    A1, A2 = [], []
    cdef double val
    for val in vals:
        A1.append(val**2)
        A2.append(val**3)

    return A1, A2

%timeit df['A1'], df['A2'] = power(df['a'])
72.7 ms ± 2.16 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

Directly assigning without apply

You can get even greater speed improvements if you use the direct vectorized operations.

%timeit df['A1'], df['A2'] = df['a'] ** 2, df['a'] ** 3
5.13 ms ± 320 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

This takes advantage of NumPy's extremely fast vectorized operations instead of our loops. We now have a 30x speedup over the original.

The simplest speed test with `apply`

The above example should clearly show how slow apply can be, but just so its extra clear let's look at the most basic example. Let's square a Series of 10 million numbers with and without apply

s = pd.Series(np.random.rand(10000000))

%timeit s.apply(calc)
3.3 s ± 57.4 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

Without apply is 50x faster

%timeit s ** 2
66 ms ± 2 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

Removing X-Powered-By

Try adding a header() call before sending headers, like:

header('X-Powered-By: Our company\'s development team');

regardless of the expose_php setting in php.ini

Finding the next available id in MySQL

In addition to Lukasz Lysik's answer - LEFT-JOIN kind of SQL.
As I understand, if have id's: 1,2,4,5 it should return 3.

SELECT u.Id + 1 AS FirstAvailableId
FROM users u
LEFT JOIN users u1 ON u1.Id = u.Id + 1
WHERE u1.Id IS NULL
ORDER BY u.Id
LIMIT 0, 1

Hope it will help some of visitors, although post are rather old.

Java SSLException: hostname in certificate didn't match

In httpclient-4.3.3.jar, there is another HttpClient to use:

public static void main (String[] args) throws Exception {
    // org.apache.http.client.HttpClient client = new DefaultHttpClient();
    org.apache.http.client.HttpClient client = HttpClientBuilder.create().build();
    System.out.println("HttpClient = " + client.getClass().toString());
    org.apache.http.client.methods.HttpPost post = new HttpPost("https://www.rideforrainbows.org/");
    org.apache.http.HttpResponse response = client.execute(post);
    java.io.InputStream is = response.getEntity().getContent();
    java.io.BufferedReader rd = new java.io.BufferedReader(new java.io.InputStreamReader(is));
    String line;
    while ((line = rd.readLine()) != null) { 
        System.out.println(line);
    }
}

This HttpClientBuilder.create().build() will return org.apache.http.impl.client.InternalHttpClient. It can handle the this hostname in certificate didn't match issue.

CURRENT_DATE/CURDATE() not working as default DATE value

I came to this page with the same question in mind, but it worked for me!, Just thought to update here , may be helpful for someone later!!

MariaDB [niffdb]> desc invoice;
+---------+--------+------+-----+---------+----------------+
| Field   | Type   | Null | Key | Default | Extra          |
+---------+--------+------+-----+---------+----------------+
| inv_id  | int(4) | NO   | PRI | NULL    | auto_increment |
| cust_id | int(4) | NO   | MUL | NULL    |                |
| inv_dt  | date   | NO   |     | NULL    |                |
| smen_id | int(4) | NO   | MUL | NULL    |                |
+---------+--------+------+-----+---------+----------------+
4 rows in set (0.003 sec)

MariaDB [niffdb]> ALTER TABLE invoice MODIFY inv_dt DATE NOT NULL DEFAULT (CURRENT_DATE);
Query OK, 0 rows affected (0.003 sec)
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [niffdb]> desc invoice;
+---------+--------+------+-----+-----------+----------------+
| Field   | Type   | Null | Key | Default   | Extra          |
+---------+--------+------+-----+-----------+----------------+
| inv_id  | int(4) | NO   | PRI | NULL      | auto_increment |
| cust_id | int(4) | NO   | MUL | NULL      |                |
| inv_dt  | date   | NO   |     | curdate() |                |
| smen_id | int(4) | NO   | MUL | NULL      |                |
+---------+--------+------+-----+-----------+----------------+
4 rows in set (0.002 sec)

MariaDB [niffdb]> SELECT VERSION();
+---------------------------+
| VERSION()                 |
+---------------------------+
| 10.3.18-MariaDB-0+deb10u1 |
+---------------------------+
1 row in set (0.010 sec)

MariaDB [niffdb]>

JQuery refresh select box

html table span entire width?

Try (in your <head> section, or existing css definitions)...

<style>
  body {
   margin:0;
   padding:0;
  }
</style>

How to create python bytes object from long hex string?

result = bytes.fromhex(some_hex_string)

How do I execute multiple SQL Statements in Access' Query Editor?

"I hoped (and still hope) that there is something like my beloved SQL*Plus for Oracle that can execute a file with all kinds of SQL Statements."

If you're looking for a simple program that can import a file and execute the SQL statements in it, take a look at DBWConsole (freeware). I have used it to process DDL scripts (table schema) as well as action queries. It does not return data sets so it's not useful for SELECT queries. It supports single line comments prefixed by -- but not multi-line comments wrapped in /* */. It supports command line parameters.

If you want an interactive UI like Oracle SQL Developer or SSMS for Access then Matthew Lock's reference to WinSQL is what you should try.

How to save a plot as image on the disk?

In some cases one wants to both save and print a base r plot. I spent a bit of time and came up with this utility function:

x = 1:10

basesave = function(expr, filename, print=T) {
  #extension
  exten = stringr::str_match(filename, "\\.(\\w+)$")[, 2]

  switch(exten,
         png = {
           png(filename)
           eval(expr, envir = parent.frame())
           dev.off()
         },
         {stop("filetype not recognized")})


  #print?
  if (print) eval(expr, envir = parent.frame())

  invisible(NULL)
}

#plots, but doesn't save
plot(x)

#saves, but doesn't plot
png("test.png")
plot(x)
dev.off()

#both
basesave(quote(plot(x)), "test.png")

#works with pipe too
quote(plot(x)) %>% basesave("test.png")

Note that one must use quote, otherwise the plot(x) call is run in the global environment and NULL gets passed to basesave().

Node Express sending image files as API response

a proper solution with streams and error handling is below:

const fs = require('fs')
const stream = require('stream')

app.get('/report/:chart_id/:user_id',(req, res) => {
  const r = fs.createReadStream('path to file') // or any other way to get a readable stream
  const ps = new stream.PassThrough() // <---- this makes a trick with stream error handling
  stream.pipeline(
   r,
   ps, // <---- this makes a trick with stream error handling
   (err) => {
    if (err) {
      console.log(err) // No such file or any other kind of error
      return res.sendStatus(400); 
    }
  })
  ps.pipe(res) // <---- this makes a trick with stream error handling
})

with Node older then 10 you will need to use pump instead of pipeline.

What is the size of a boolean variable in Java?

It's virtual machine dependent.

How can I encode a string to Base64 in Swift?

Swift 4.2

var base64String = "my fancy string".data(using: .utf8, allowLossyConversion: false)?.base64EncodedString()

to decode, see (from https://gist.github.com/stinger/a8a0381a57b4ac530dd029458273f31a)

//: # Swift 3: Base64 encoding and decoding
import Foundation

extension String {
//: ### Base64 encoding a string
    func base64Encoded() -> String? {
        if let data = self.data(using: .utf8) {
            return data.base64EncodedString()
        }
        return nil
    }

//: ### Base64 decoding a string
    func base64Decoded() -> String? {
        if let data = Data(base64Encoded: self) {
            return String(data: data, encoding: .utf8)
        }
        return nil
    }
}
var str = "Hello, playground"
print("Original string: \"\(str)\"")

if let base64Str = str.base64Encoded() {
    print("Base64 encoded string: \"\(base64Str)\"")
    if let trs = base64Str.base64Decoded() {
        print("Base64 decoded string: \"\(trs)\"")
        print("Check if base64 decoded string equals the original string: \(str == trs)")
    }
}

Setting ANDROID_HOME enviromental variable on Mac OS X

I'm using React Native with Catalina mac os and zsh shell

1- touch ~/.zshrc

2- open ~/.zshrc

3- according to React Native android setup copy and past

export ANDROID_HOME=$HOME/Library/Android/sdk
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools

to the opened text file then save and close the file.

4- run source ~/.zshrc and make sure to restart your terminal.

5- run adb you will get something like

Android Debug Bridge version 1.0.41 Version 30.0.0-6374843

thanks for this documented

update1 16/2/2021

this solution works with Big Sur as well.

How do I increase the scrollback buffer in a running screen session?

WARNING: setting this value too high may cause your system to experience a significant hiccup. The higher the value you set, the more virtual memory is allocated to the screen process when initiating the screen session. I set my ~/.screenrc to "defscrollback 123456789" and when I initiated a screen, my entire system froze up for a good 10 minutes before coming back to the point that I was able to kill the screen process (which was consuming 16.6GB of VIRT mem by then).

How to call python script on excel vba?

There are a couple of ways to solve this problem

Pyinx - a pretty lightweight tool that allows you to call Python from withing the excel process space http://code.google.com/p/pyinex/

I've used this one a few years ago (back when it was being actively developed) and it worked quite well

If you don't mind paying, this looks pretty good

https://datanitro.com/product.html

I've never used it though

Though if you are already writting in Python, maybe you could drop excel entirely and do everything in pure python? It's a lot easier to maintain one code base (python) rather than 2 (python + whatever excel overlay you have).

If you really have to output your data into excel there are even some pretty good tools for that in Python. If that may work better let me know and I'll get the links.

Fastest method of screen capturing on Windows

With Windows 8, Microsoft introduced the Windows Desktop Duplication API. That is the officially recommended way of doing it. One nice feature it has for screencasting is that it detects window movement, so you can transmit block deltas when windows get moved around, instead of raw pixels. Also, it tells you which rectangles have changed, from one frame to the next.

The Microsoft example code is pretty complex, but the API is actually simple and easy to use. I've put together an example project which is much simpler than the official example:

https://github.com/bmharper/WindowsDesktopDuplicationSample

Docs: https://docs.microsoft.com/en-gb/windows/desktop/direct3ddxgi/desktop-dup-api

Microsoft official example code: https://code.msdn.microsoft.com/windowsdesktop/Desktop-Duplication-Sample-da4c696a

Downloading a picture via urllib and python

Another way to do this is via the fastai library. This worked like a charm for me. I was facing a SSL: CERTIFICATE_VERIFY_FAILED Error using urlretrieve so I tried that.

url = 'https://www.linkdoesntexist.com/lennon.jpg'
fastai.core.download_url(url,'image1.jpg', show_progress=False)

AngularJS $http, CORS and http authentication

No you don't have to put credentials, You have to put headers on client side eg:

 $http({
        url: 'url of service',
        method: "POST",
        data: {test :  name },
        withCredentials: true,
        headers: {
                    'Content-Type': 'application/json; charset=utf-8'
        }
    });

And and on server side you have to put headers to this is example for nodejs:

/**
 * On all requests add headers
 */
app.all('*', function(req, res,next) {


    /**
     * Response settings
     * @type {Object}
     */
    var responseSettings = {
        "AccessControlAllowOrigin": req.headers.origin,
        "AccessControlAllowHeaders": "Content-Type,X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5,  Date, X-Api-Version, X-File-Name",
        "AccessControlAllowMethods": "POST, GET, PUT, DELETE, OPTIONS",
        "AccessControlAllowCredentials": true
    };

    /**
     * Headers
     */
    res.header("Access-Control-Allow-Credentials", responseSettings.AccessControlAllowCredentials);
    res.header("Access-Control-Allow-Origin",  responseSettings.AccessControlAllowOrigin);
    res.header("Access-Control-Allow-Headers", (req.headers['access-control-request-headers']) ? req.headers['access-control-request-headers'] : "x-requested-with");
    res.header("Access-Control-Allow-Methods", (req.headers['access-control-request-method']) ? req.headers['access-control-request-method'] : responseSettings.AccessControlAllowMethods);

    if ('OPTIONS' == req.method) {
        res.send(200);
    }
    else {
        next();
    }


});

Getting binary (base64) data from HTML5 Canvas (readAsBinaryString)

Seeing how you draw your canvas with

$("canvas").drawImage();

it seems that you use jQuery Canvas (jCanvas) by Caleb Evans. I actually use that plugin and it has a simple way to retrieve canvas base64 image string with $('canvas').getCanvasImage();

Here's a working Fiddle for you: http://jsfiddle.net/e6nqzxpn/

Maven project.build.directory

You can find those maven properties in the super pom.

You find the jar here:

${M2_HOME}/lib/maven-model-builder-3.0.3.jar

Open the jar with 7-zip or some other archiver (or use the jar tool).

Navigate to

org/apache/maven/model

There you'll find the pom-4.0.0.xml.

It contains all those "short cuts":

<project>
    ...
    <build>
        <directory>${project.basedir}/target</directory>
        <outputDirectory>${project.build.directory}/classes</outputDirectory>
        <finalName>${project.artifactId}-${project.version}</finalName>
        <testOutputDirectory>${project.build.directory}/test-classes</testOutputDirectory>
        <sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>
        <scriptSourceDirectory>src/main/scripts</scriptSourceDirectory>
        <testSourceDirectory>${project.basedir}/src/test/java</testSourceDirectory>
        <resources>
            <resource>
                <directory>${project.basedir}/src/main/resources</directory>
            </resource>
        </resources>
        <testResources>
            <testResource>
                <directory>${project.basedir}/src/test/resources</directory>
            </testResource>
        </testResources>
        ...
    </build>
    ...
</project>

Update

After some lobbying I am adding a link to the pom-4.0.0.xml. This allows you to see the properties without opening up the local jar file.

Failed to load resource: the server responded with a status of 404 (Not Found) css

Use the following Code:-

../css/main.css

Note: The "../" is shorthand for "The containing directory", or "Up one directory".

If you don't know the previous folder this will be very helpful..

Passing a String by Reference in Java?

In Java nothing is passed by reference. Everything is passed by value. Object references are passed by value. Additionally Strings are immutable. So when you append to the passed String you just get a new String. You could use a return value, or pass a StringBuffer instead.

SQL: Select columns with NULL values only

Or did you want to just see if a column only has NULL values (and, thus, is probably unused)?

Further clarification of the question might help.

EDIT: Ok.. here's some really rough code to get you going...

SET NOCOUNT ON
DECLARE @TableName Varchar(100)
SET @TableName='YourTableName'
CREATE TABLE #NullColumns (ColumnName Varchar(100), OnlyNulls BIT)
INSERT INTO #NullColumns (ColumnName, OnlyNulls) SELECT c.name, 0 FROM syscolumns c INNER JOIN sysobjects o ON c.id = o.id AND o.name = @TableName AND o.xtype = 'U'
DECLARE @DynamicSQL AS Nvarchar(2000)
DECLARE @ColumnName Varchar(100)
DECLARE @RC INT
    SELECT TOP 1 @ColumnName = ColumnName FROM #NullColumns WHERE OnlyNulls=0
    WHILE @@ROWCOUNT > 0
    BEGIN
        SET @RC=0
        SET @DynamicSQL = 'SELECT TOP 1 1 As HasNonNulls FROM ' + @TableName + ' (nolock) WHERE ''' + @ColumnName + ''' IS NOT NULL'
        EXEC sp_executesql @DynamicSQL
        set @RC=@@rowcount
        IF @RC=1
        BEGIN
            SET @DynamicSQL = 'UPDATE #NullColumns SET OnlyNulls=1 WHERE ColumnName=''' + @ColumnName + ''''
            EXEC sp_executesql @DynamicSQL
        END
        ELSE
        BEGIN
            SET @DynamicSQL = 'DELETE FROM #NullColumns WHERE ColumnName=''' + @ColumnName+ ''''
            EXEC sp_executesql @DynamicSQL
        END
    SELECT TOP 1 @ColumnName = ColumnName FROM #NullColumns WHERE OnlyNulls=0
    END

SELECT * FROM #NullColumns

DROP TABLE #NullColumns
SET NOCOUNT OFF

Yes, there are easier ways, but I have a meeting to go to right now. Good luck!

MySQL foreach alternative for procedure

Here's the mysql reference for cursors. So I'm guessing it's something like this:

  DECLARE done INT DEFAULT 0;
  DECLARE products_id INT;
  DECLARE result varchar(4000);
  DECLARE cur1 CURSOR FOR SELECT products_id FROM sets_products WHERE set_id = 1;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

  OPEN cur1;

  REPEAT
    FETCH cur1 INTO products_id;
    IF NOT done THEN
      CALL generate_parameter_list(@product_id, @result);
      SET param = param + "," + result; -- not sure on this syntax
    END IF;
  UNTIL done END REPEAT;

  CLOSE cur1;

  -- now trim off the trailing , if desired

How do I make flex box work in safari?

Just try -webkit-flexbox. it's working for safari. webkit-flex safari will not taking.

How do I force make/GCC to show me the commands?

Since GNU Make version 4.0, the --trace argument is a nice way to tell what and why a makefile do, outputing lines like:

makefile:8: target 'foo.o' does not exist

makefile:12: update target 'foo' due to: bar

Display the current time and date in an Android application

If you wish to work with date/time in android I recommend you to use ThreeTenABP which is a version of java.time.* package (available starting from API 26 on android) shipped with Java 8 available as a replacement for java.util.Date and java.util.Calendar.

LocalDate localDate = LocalDate.now();
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM);
String date = localDate.format(formatter);
textView.setText(date);

How to directly move camera to current location in Google Maps Android API v2?

The above answer is not according to what Google Doc Referred for Location Tracking in Google api v2.

I just followed the official tutorial and ended up with this class that is fetching the current location and centring the map on it as soon as i get that.

you can extend this class to have LocationReciever to have periodic Location Update. I just executed this code on api level 7

http://developer.android.com/training/location/retrieve-current.html

Here it goes.

import android.app.Activity;
import android.app.Dialog;
import android.content.Intent;
import android.content.IntentSender;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;


public class MainActivity extends FragmentActivity implements 
    GooglePlayServicesClient.ConnectionCallbacks, 
    GooglePlayServicesClient.OnConnectionFailedListener{

private SupportMapFragment mapFragment;
private GoogleMap map;
private LocationClient mLocationClient;
/*
 * Define a request code to send to Google Play services
 * This code is returned in Activity.onActivityResult
 */
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;

// Define a DialogFragment that displays the error dialog
public static class ErrorDialogFragment extends DialogFragment {

    // Global field to contain the error dialog
    private Dialog mDialog;

    // Default constructor. Sets the dialog field to null
    public ErrorDialogFragment() {
        super();
        mDialog = null;
    }

    // Set the dialog to display
    public void setDialog(Dialog dialog) {
        mDialog = dialog;
    }

    // Return a Dialog to the DialogFragment.
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        return mDialog;
    }
}

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

    mLocationClient = new LocationClient(this, this, this);

    mapFragment = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map));
    map = mapFragment.getMap();

    map.setMyLocationEnabled(true);

}

/*
 * Called when the Activity becomes visible.
 */
@Override
protected void onStart() {
    super.onStart();
    // Connect the client.
    if(isGooglePlayServicesAvailable()){
        mLocationClient.connect();
    }

}

/*
 * Called when the Activity is no longer visible.
 */
@Override
protected void onStop() {
    // Disconnecting the client invalidates it.
    mLocationClient.disconnect();
    super.onStop();
}

/*
 * Handle results returned to the FragmentActivity
 * by Google Play services
 */
@Override
protected void onActivityResult(
                int requestCode, int resultCode, Intent data) {
    // Decide what to do based on the original request code
    switch (requestCode) {

        case CONNECTION_FAILURE_RESOLUTION_REQUEST:
            /*
             * If the result code is Activity.RESULT_OK, try
             * to connect again
             */
            switch (resultCode) {
                case Activity.RESULT_OK:
                    mLocationClient.connect();
                    break;
            }

    }
}

private boolean isGooglePlayServicesAvailable() {
    // Check that Google Play services is available
    int resultCode =  GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
    // If Google Play services is available
    if (ConnectionResult.SUCCESS == resultCode) {
        // In debug mode, log the status
        Log.d("Location Updates", "Google Play services is available.");
        return true;
    } else {
        // Get the error dialog from Google Play services
        Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog( resultCode,
                                                                                                              this,
                                                                                                              CONNECTION_FAILURE_RESOLUTION_REQUEST);

        // If Google Play services can provide an error dialog
        if (errorDialog != null) {
            // Create a new DialogFragment for the error dialog
            ErrorDialogFragment errorFragment = new ErrorDialogFragment();
            errorFragment.setDialog(errorDialog);
            errorFragment.show(getSupportFragmentManager(), "Location Updates");
        }

        return false;
    }
}

/*
 * Called by Location Services when the request to connect the
 * client finishes successfully. At this point, you can
 * request the current location or start periodic updates
 */
@Override
public void onConnected(Bundle dataBundle) {
    // Display the connection status
    Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();
    Location location = mLocationClient.getLastLocation();
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
    CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(latLng, 17);
    map.animateCamera(cameraUpdate);
}

/*
 * Called by Location Services if the connection to the
 * location client drops because of an error.
 */
@Override
public void onDisconnected() {
    // Display the connection status
    Toast.makeText(this, "Disconnected. Please re-connect.",
            Toast.LENGTH_SHORT).show();
}

/*
 * Called by Location Services if the attempt to
 * Location Services fails.
 */
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    /*
     * Google Play services can resolve some errors it detects.
     * If the error has a resolution, try sending an Intent to
     * start a Google Play services activity that can resolve
     * error.
     */
    if (connectionResult.hasResolution()) {
        try {
            // Start an Activity that tries to resolve the error
            connectionResult.startResolutionForResult(
                    this,
                    CONNECTION_FAILURE_RESOLUTION_REQUEST);
            /*
            * Thrown if Google Play services canceled the original
            * PendingIntent
            */
        } catch (IntentSender.SendIntentException e) {
            // Log the error
            e.printStackTrace();
        }
    } else {
       Toast.makeText(getApplicationContext(), "Sorry. Location services not available to you", Toast.LENGTH_LONG).show();
    }
}

}

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.

'float' vs. 'double' precision

float : 23 bits of significand, 8 bits of exponent, and 1 sign bit.

double : 52 bits of significand, 11 bits of exponent, and 1 sign bit.

Show dialog from fragment?

You should use a DialogFragment instead.

Best way to get whole number part of a Decimal number

By the way guys, (int)Decimal.MaxValue will overflow. You can't get the "int" part of a decimal because the decimal is too friggen big to put in the int box. Just checked... its even too big for a long (Int64).

If you want the bit of a Decimal value to the LEFT of the dot, you need to do this:

Math.Truncate(number)

and return the value as... A DECIMAL or a DOUBLE.

edit: Truncate is definitely the correct function!

React Native fixed footer

Simple stuff here:

Incase you don't need a ScrollView for this approach you can go with the below code to achieve Something like this :

<View style={{flex: 1, backgroundColor:'grey'}}>
    <View style={{flex: 1, backgroundColor: 'red'}} />
    <View style={{height: 100, backgroundColor: 'green'}} />
</View>

Installation error: INSTALL_FAILED_OLDER_SDK

Go in your project's build.cradle file and add

defaultConfig {
    minSdkVersion versions.minSdk

This makes it that your application conforms to the minimum SDK your device is running.

current/duration time of html5 video?

Working example here at : http://jsfiddle.net/tQ2CZ/1/

HTML

<div id="video_container">
<video poster="http://media.w3.org/2010/05/sintel/poster.png" preload="none" controls="" id="video" tabindex="0">
    <source type="video/mp4" src="http://media.w3.org/2010/05/sintel/trailer.mp4" id="mp4"></source>
    <source type="video/webm" src="http://media.w3.org/2010/05/sintel/trailer.webm" id="webm"></source>
    <source type="video/ogg" src="http://media.w3.org/2010/05/sintel/trailer.ogv" id="ogv"></source>
    <p>Your user agent does not support the HTML5 Video element.</p>
</video>
</div>

<div>Current Time : <span  id="currentTime">0</span></div>
<div>Total time : <span id="totalTime">0</span></div>

$(function(){
$('#currentTime').html($('#video_container').find('video').get(0).load());
$('#currentTime').html($('#video_container').find('video').get(0).play());
})
setInterval(function(){
$('#currentTime').html($('#video_container').find('video').get(0).currentTime);
$('#totalTime').html($('#video_container').find('video').get(0).duration);    
},500)

MySQL - Meaning of "PRIMARY KEY", "UNIQUE KEY" and "KEY" when used together while creating a table

A key is just a normal index. A way over simplification is to think of it like a card catalog at a library. It points MySQL in the right direction.

A unique key is also used for improved searching speed, but it has the constraint that there can be no duplicated items (there are no two x and y where x is not y and x == y).

The manual explains it as follows:

A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. This constraint does not apply to NULL values except for the BDB storage engine. For other engines, a UNIQUE index permits multiple NULL values for columns that can contain NULL. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix.

A primary key is a 'special' unique key. It basically is a unique key, except that it's used to identify something.

The manual explains how indexes are used in general: here.

In MSSQL, the concepts are similar. There are indexes, unique constraints and primary keys.

Untested, but I believe the MSSQL equivalent is:

CREATE TABLE tmp (
  id int NOT NULL PRIMARY KEY IDENTITY,
  uid varchar(255) NOT NULL CONSTRAINT uid_unique UNIQUE,
  name varchar(255) NOT NULL,
  tag int NOT NULL DEFAULT 0,
  description varchar(255),
);

CREATE INDEX idx_name ON tmp (name);
CREATE INDEX idx_tag ON tmp (tag);

Edit: the code above is tested to be correct; however, I suspect that there's a much better syntax for doing it. Been a while since I've used SQL server, and apparently I've forgotten quite a bit :).

Save a file in json format using Notepad++

enter image description here Save the file as *.txt and then rename the file and change the file extension to json

Why, Fatal error: Class 'PHPUnit_Framework_TestCase' not found in ...?

NOTICE: Command php bin/console generate:doctrine:crud also create TestController in src/Tests so it can throw error when you tried to start server if you don't have UnitTests. Remove the file fix it!

Sum across multiple columns with dplyr

I would use regular expression matching to sum over variables with certain pattern names. For example:

df <- df %>% mutate(sum1 = rowSums(.[grep("x[3-5]", names(.))], na.rm = TRUE),
                    sum_all = rowSums(.[grep("x", names(.))], na.rm = TRUE))

This way you can create more than one variable as a sum of certain group of variables of your data frame.

Refresh Part of Page (div)

You need to do that on the client side for instance with jQuery.

Let's say you want to retrieve HTML into div with ID mydiv:

<h1>My page</h1>
<div id="mydiv">
    <h2>This div is updated</h2>
</div>

You can update this part of the page with jQuery as follows:

$.get('/api/mydiv', function(data) {
  $('#mydiv').html(data);
});

In the server-side you need to implement handler for requests coming to /api/mydiv and return the fragment of HTML that goes inside mydiv.

See this Fiddle I made for you for a fun example using jQuery get with JSON response data: http://jsfiddle.net/t35F9/1/

How to convert an object to JSON correctly in Angular 2 with TypeScript

If you are solely interested in outputting the JSON somewhere in your HTML, you could also use a pipe inside an interpolation. For example:

<p> {{ product | json }} </p>

I am not entirely sure it works for every AngularJS version, but it works perfectly in my Ionic App (which uses Angular 2+).

Is it possible to 'prefill' a google form using data from a google spreadsheet?

You can create a pre-filled form URL from within the Form Editor, as described in the documentation for Drive Forms. You'll end up with a URL like this, for example:

https://docs.google.com/forms/d/--form-id--/viewform?entry.726721210=Mike+Jones&entry.787184751=1975-05-09&entry.1381372492&entry.960923899

buildUrls()

In this example, question 1, "Name", has an ID of 726721210, while question 2, "Birthday" is 787184751. Questions 3 and 4 are blank.

You could generate the pre-filled URL by adapting the one provided through the UI to be a template, like this:

function buildUrls() {
  var template = "https://docs.google.com/forms/d/--form-id--/viewform?entry.726721210=##Name##&entry.787184751=##Birthday##&entry.1381372492&entry.960923899";
  var ss = SpreadsheetApp.getActive().getSheetByName("Sheet1");  // Email, Name, Birthday
  var data = ss.getDataRange().getValues();

  // Skip headers, then build URLs for each row in Sheet1.
  for (var i = 1; i < data.length; i++ ) {
    var url = template.replace('##Name##',escape(data[i][1]))
                      .replace('##Birthday##',data[i][2].yyyymmdd());  // see yyyymmdd below
    Logger.log(url);  // You could do something more useful here.
  }
};

This is effective enough - you could email the pre-filled URL to each person, and they'd have some questions already filled in.

betterBuildUrls()

Instead of creating our template using brute force, we can piece it together programmatically. This will have the advantage that we can re-use the code without needing to remember to change the template.

Each question in a form is an item. For this example, let's assume the form has only 4 questions, as you've described them. Item [0] is "Name", [1] is "Birthday", and so on.

We can create a form response, which we won't submit - instead, we'll partially complete the form, only to get the pre-filled form URL. Since the Forms API understands the data types of each item, we can avoid manipulating the string format of dates and other types, which simplifies our code somewhat.

(EDIT: There's a more general version of this in How to prefill Google form checkboxes?)

/**
 * Use Form API to generate pre-filled form URLs
 */
function betterBuildUrls() {
  var ss = SpreadsheetApp.getActive();
  var sheet = ss.getSheetByName("Sheet1");
  var data = ss.getDataRange().getValues();  // Data for pre-fill

  var formUrl = ss.getFormUrl();             // Use form attached to sheet
  var form = FormApp.openByUrl(formUrl);
  var items = form.getItems();

  // Skip headers, then build URLs for each row in Sheet1.
  for (var i = 1; i < data.length; i++ ) {
    // Create a form response object, and prefill it
    var formResponse = form.createResponse();

    // Prefill Name
    var formItem = items[0].asTextItem();
    var response = formItem.createResponse(data[i][1]);
    formResponse.withItemResponse(response);

    // Prefill Birthday
    formItem = items[1].asDateItem();
    response = formItem.createResponse(data[i][2]);
    formResponse.withItemResponse(response);

    // Get prefilled form URL
    var url = formResponse.toPrefilledUrl();
    Logger.log(url);  // You could do something more useful here.
  }
};

yymmdd Function

Any date item in the pre-filled form URL is expected to be in this format: yyyy-mm-dd. This helper function extends the Date object with a new method to handle the conversion.

When reading dates from a spreadsheet, you'll end up with a javascript Date object, as long as the format of the data is recognizable as a date. (Your example is not recognizable, so instead of May 9th 1975 you could use 5/9/1975.)

// From http://blog.justin.kelly.org.au/simple-javascript-function-to-format-the-date-as-yyyy-mm-dd/
Date.prototype.yyyymmdd = function() {
  var yyyy = this.getFullYear().toString();                                    
  var mm = (this.getMonth()+1).toString(); // getMonth() is zero-based         
  var dd  = this.getDate().toString();             

  return yyyy + '-' + (mm[1]?mm:"0"+mm[0]) + '-' + (dd[1]?dd:"0"+dd[0]);
};

assembly to compare two numbers

As already mentioned, usually the comparison is done through subtraction.
For example, X86 Assembly/Control Flow.

At the hardware level there are special digital circuits for doing the calculations, like adders.

What is the correct syntax for 'else if'?

Here is a little refactoring of your function (it does not use "else" or "elif"):

def function(a):
    if a not in (1, 2):
        a = 3
    print(str(a) + "a")

@ghostdog74: Python 3 requires parentheses for "print".

Server.MapPath - Physical path given, virtual path expected

var files = Directory.GetFiles(@"E:\ftproot\sales");

GlobalConfiguration.Configure() not present after Web API 2 and .NET 4.5.1 migration

None of these ideas helped my project using MVC 5.2.2.

System.web.Http 5.2.2 was already installed
Deleting the Packages folder and completely re-downloading all NuGet libraries did nothing
Web.config already had a dependentAssembly entry for System.Web.Http

Forcing a reinstall corrected the problem. From the NuGet package manager console:

update-Package -reinstall Microsoft.AspNet.WebApi.WebHost

"unary operator expected" error in Bash if condition

If you know you're always going to use bash, it's much easier to always use the double bracket conditional compound command [[ ... ]], instead of the Posix-compatible single bracket version [ ... ]. Inside a [[ ... ]] compound, word-splitting and pathname expansion are not applied to words, so you can rely on

if [[ $aug1 == "and" ]];

to compare the value of $aug1 with the string and.

If you use [ ... ], you always need to remember to double quote variables like this:

if [ "$aug1" = "and" ];

If you don't quote the variable expansion and the variable is undefined or empty, it vanishes from the scene of the crime, leaving only

if [ = "and" ];

which is not a valid syntax. (It would also fail with a different error message if $aug1 included white space or shell metacharacters.)

The modern [[ operator has lots of other nice features, including regular expression matching.

Using a BOOL property

There's no benefit to using properties with primitive types. @property is used with heap allocated NSObjects like NSString*, NSNumber*, UIButton*, and etc, because memory managed accessors are created for free. When you create a BOOL, the value is always allocated on the stack and does not require any special accessors to prevent memory leakage. isWorking is simply the popular way of expressing the state of a boolean value.

In another OO language you would make a variable private bool working; and two accessors: SetWorking for the setter and IsWorking for the accessor.

Edit In Place Content Editing

I've modified your plunker to get it working via angular-xeditable:

http://plnkr.co/edit/xUDrOS?p=preview

It is common solution for inline editing - you creale hyperlinks with editable-text directive that toggles into <input type="text"> tag:

<a href="#" editable-text="bday.name" ng-click="myform.$show()" e-placeholder="Name">
    {{bday.name || 'empty'}}
</a>

For date I used editable-date directive that toggles into html5 <input type="date">.

Is true == 1 and false == 0 in JavaScript?

In JavaScript, == is pronounced "Probably Equals".

What I mean by that is that JavaScript will automatically convert the Boolean into an integer and then attempt to compare the two sides.

For real equality, use the === operator.

Bootstrap 3 Carousel Not Working

Here is the changes you need to be done

just replace the carousel div with the below code

You have missed the '#' for data-target and add active class for the first item

<div id="carousel" class="carousel slide" data-ride="carousel">
            <ol class="carousel-indicators">
                <li data-target="#carousel" data-slide-to="0"></li>
                <li data-target="#carousel" data-slide-to="1"></li>
                <li data-target="#carousel" data-slide-to="2"></li>
            </ol>
            <div class="carousel-inner">
                <div class="item active">
                    <img src="img/slide_1.png" alt="Slide 1">
                </div>
                <div class="item">
                    <img src="img/slide_2.png" alt="Slide 2">
                </div>
                <div class="item">
                    <img src="img/slide_3.png" alt="Slide 3">
                </div>
            </div>
            <a href="#carousel" class="left carousel-control" data-slide="prev">
                <span class="glyphicon glyphicon-chevron-left"></span>
            </a>
            <a href="#carousel" class="right carousel-control" data-slide="next">
                <span class="glyphicon glyphicon-chevron-right"></span>
            </a>
        </div>

How do you set autocommit in an SQL Server session?

I wanted a more permanent and quicker way. Because I tend to forget to add extra lines before writing my actual Update/Insert queries.

I did it by checking SET IMPLICIT_TRANSACTIONS check-box from Options. To navigate to Options Select Tools>Options>Query Execution>SQL Server>ANSI in your Microsoft SQL Server Management Studio.

Just make sure to execute commit or rollback after you are done executing your queries. Otherwise, the table you would have run the query will be locked for others.

How to get the caller's method name in the called method?

I found a way if you're going across classes and want the class the method belongs to AND the method. It takes a bit of extraction work but it makes its point. This works in Python 2.7.13.

import inspect, os

class ClassOne:
    def method1(self):
        classtwoObj.method2()

class ClassTwo:
    def method2(self):
        curframe = inspect.currentframe()
        calframe = inspect.getouterframes(curframe, 4)
        print '\nI was called from', calframe[1][3], \
        'in', calframe[1][4][0][6: -2]

# create objects to access class methods
classoneObj = ClassOne()
classtwoObj = ClassTwo()

# start the program
os.system('cls')
classoneObj.method1()

Performance differences between ArrayList and LinkedList

Both remove() and insert() have a runtime efficiency of O(n) for both ArrayLists and LinkedLists. However the reason behind the linear processing time comes from two very different reasons:

In an ArrayList you get to the element in O(1), but actually removing or inserting something makes it O(n) because all the following elements need to be changed.

In a LinkedList it takes O(n) to actually get to the desired element, because we have to start at the very beginning until we reach the desired index. Removing or inserting is constant once we get there, because we only have to change 1 reference for remove() and 2 references for insert().

Which of the two is faster for inserting and removing depends on where it happens. If we are closer to the beginning the LinkedList will be faster, because we have to go through relatively few elements. If we are closer to the end an ArrayList will be faster, because we get there in constant time and only have to change the few remaining elements that follow it.

Bonus: While there is no way of making these two methods O(1) for an ArrayList, there actually is a way to do this in LinkedLists. Lets say we want to go through the entire List removing and inserting elements on our way. Usually you would start from the very beginning for each elements using the LinkedList, we could also "save" the current element we're working on with an Iterator. With the help of the Iterator we get a O(1) efficiency for remove() and insert() when working in a LinkedList. Making it the only performance benefit I'm aware of where a LinkedList is always better than an ArrayList.

Find JavaScript function definition in Chrome

In Google chrome, Inspect element tool you can view any Javascript function definition.

Click on the Sources tab. Then select the index page. Search for the function.

Select the function then Right-click on the function and select "Evaluate selected text in console."

Displaying unicode symbols in HTML

Unlike proposed by Nicolas, the meta tag isn’t actually ignored by the browsers. However, the Content-Type HTTP header always has precedence over the presence of a meta tag in the document.

So make sure that you either send the correct encoding via the HTTP header, or don’t send this HTTP header at all (not recommended). The meta tag is mainly a fallback option for local documents which aren’t sent via HTTP traffic.

Using HTML entities should also be considered a workaround – that’s tiptoeing around the real problem. Configuring the web server properly prevents a lot of nuisance.

Fragment onCreateView and onActivityCreated called twice

The two upvoted answers here show solutions for an Activity with navigation mode NAVIGATION_MODE_TABS, but I had the same issue with a NAVIGATION_MODE_LIST. It caused my Fragments to inexplicably lose their state when the screen orientation changed, which was really annoying. Thankfully, due to their helpful code I managed to figure it out.

Basically, when using a list navigation, ``onNavigationItemSelected()is automatically called when your activity is created/re-created, whether you like it or not. To prevent your Fragment'sonCreateView()from being called twice, this initial automatic call toonNavigationItemSelected()should check whether the Fragment is already in existence inside your Activity. If it is, return immediately, because there is nothing to do; if it isn't, then simply construct the Fragment and add it to the Activity like you normally would. Performing this check prevents your Fragment from needlessly being created again, which is what causesonCreateView()` to be called twice!

See my onNavigationItemSelected() implementation below.

public class MyActivity extends FragmentActivity implements ActionBar.OnNavigationListener
{
    private static final String STATE_SELECTED_NAVIGATION_ITEM = "selected_navigation_item";

    private boolean mIsUserInitiatedNavItemSelection;

    // ... constructor code, etc.

    @Override
    public void onRestoreInstanceState(Bundle savedInstanceState)
    {
        super.onRestoreInstanceState(savedInstanceState);

        if (savedInstanceState.containsKey(STATE_SELECTED_NAVIGATION_ITEM))
        {
            getActionBar().setSelectedNavigationItem(savedInstanceState.getInt(STATE_SELECTED_NAVIGATION_ITEM));
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState)
    {
        outState.putInt(STATE_SELECTED_NAVIGATION_ITEM, getActionBar().getSelectedNavigationIndex());

        super.onSaveInstanceState(outState);
    }

    @Override
    public boolean onNavigationItemSelected(int position, long id)
    {    
        Fragment fragment;
        switch (position)
        {
            // ... choose and construct fragment here
        }

        // is this the automatic (non-user initiated) call to onNavigationItemSelected()
        // that occurs when the activity is created/re-created?
        if (!mIsUserInitiatedNavItemSelection)
        {
            // all subsequent calls to onNavigationItemSelected() won't be automatic
            mIsUserInitiatedNavItemSelection = true;

            // has the same fragment already replaced the container and assumed its id?
            Fragment existingFragment = getSupportFragmentManager().findFragmentById(R.id.container);
            if (existingFragment != null && existingFragment.getClass().equals(fragment.getClass()))
            {
                return true; //nothing to do, because the fragment is already there 
            }
        }

        getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment).commit();
        return true;
    }
}

I borrowed inspiration for this solution from here.

Android fastboot waiting for devices

The short version of the page linked by D Shu (and without the horrible popover ads) is that this "waiting for device" problem happens when the USB device node is not accessible to your current user. The USB id is different in fastboot mode, so you can easily have permission to it in adb but not in fastboot.

To fix it (on Ubuntu; other systems may be slightly different):

Run lsusb -v | less and find the relevant section which will look something like this:

Bus 001 Device 027: ID 18d1:4e30 Google Inc. 
Couldn't open device, some information will be missing
Device Descriptor:
...
  idVendor           0x18d1 Google Inc.

Now do

sudo vi /etc/udev/rules.d/11-android.rules

it's ok if that file does not yet exist; create it with a line like this, inserting your own username and vendor id:

SUBSYSTEMS=="usb", ATTRS{idVendor}=="18d1", MODE="0640", OWNER="mbp"

then

sudo service udev restart

then verify the device node permissions have changed:

ls -Rl /dev/bus/usb

The even shorter cheesy version is to just run fastboot as root. But then you need to run every command that talks to the device as root, which tends to cause other complications. Simpler just to fix the permissions in the long run.

Programs & Examples On #Pybinding