Programs & Examples On #Pastrykit

What are the differences between a superkey and a candidate key?

Super Key: A superkey is any set of attributes for which the values are guaranteed to be unique for all possible set of tuples in a table at all time.

Candidate Key: A candidate key is a 'minimal' super key meaning the smallest subset of superkey attribute which is unique.

How do you cache an image in Javascript

Adding for completeness of the answers: preloading with HTML

<link rel="preload" href="bg-image-wide.png" as="image">

Other preloading features exist, but none are quite as fit for purpose as <link rel="preload">:

  • <link rel="prefetch"> has been supported in browsers for a long time, but it is intended for prefetching resources that will be used in the next navigation/page load (e.g. when you go to the next page). This is fine, but isn't useful for the current page! In addition, browsers will give prefetch resources a lower priority than preload ones — the current page is more important than the next. See Link prefetching FAQ for more details.
  • <link rel="prerender"> renders a specified webpage in the background, speeding up its load if the user navigates to it. Because of the potential to waste users bandwidth, Chrome treats prerender as a NoState prefetch instead.
  • <link rel="subresource"> was supported in Chrome a while ago, and was intended to tackle the same issue as preload, but it had a problem: there was no way to work out a priority for the items (as didn't exist back then), so they all got fetched with fairly low priority.

There are a number of script-based resource loaders out there, but they don't have any power over the browser's fetch prioritization queue, and are subject to much the same performance problems.

Source: https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content

Error inflating class android.support.v7.widget.Toolbar?

I have fixed this problem by modifying app build.gradle file.

For Gradle Plugin 2.0+

 android {  
   defaultConfig {  
     vectorDrawables.useSupportLibrary = true  
    }  
 }  

For Gradle Plugin 1.5

 android {  
   defaultConfig {  

     generatedDensities = []  
  }  

  aaptOptions {  
    additionalParameters "--no-version-vectors"  
  }  
 } 

Sleep for milliseconds

If using MS Visual C++ 10.0, you can do this with standard library facilities:

Concurrency::wait(milliseconds);

you will need:

#include <concrt.h>

Spring AMQP + RabbitMQ 3.3.5 ACCESS_REFUSED - Login was refused using authentication mechanism PLAIN

user 'guest' can only connect via localhost

That's true since RabbitMQ 3.3.x. Hence you should upgrade to the same version the client library, or just upgrade Spring AMQP to the latest version (if you use dependency managent system).

Previous version of client used 127.0.0.1 as default value for the host option of ConnectionFactory.

How to use a dot "." to access members of dictionary?

I recently came across the 'Box' library which does the same thing.

Installation command : pip install python-box

Example:

from box import Box

mydict = {"key1":{"v1":0.375,
                    "v2":0.625},
          "key2":0.125,
          }
mydict = Box(mydict)

print(mydict.key1.v1)

I found it to be more effective than other existing libraries like dotmap, which generate python recursion error when you have large nested dicts.

link to library and details: https://pypi.org/project/python-box/

Converting a String array into an int Array in java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class array_test {

public static void main(String args[]) throws IOException{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line = br.readLine();

String[] s_array = line.split(" ");

/* Splitting the array of number separated by space into string array.*/

Integer [] a = new Integer[s_array.length];

/Creating the int array of size equals to string array./

    for(int i =0; i<a.length;i++)
    {
        a[i]= Integer.parseInt(s_array[i]);// Parsing from string to int

        System.out.println(a[i]);
    }

    // your integer array is ready to use.

}

}

Finding the length of an integer in C

int get_int_len (int value){
  int l=1;
  while(value>9){ l++; value/=10; }
  return l;
}

and second one will work for negative numbers too:

int get_int_len_with_negative_too (int value){
  int l=!value;
  while(value){ l++; value/=10; }
  return l;
}

How can I specify a local gem in my Gemfile?

You can also reference a local gem with git if you happen to be working on it.

gem 'foo',
  :git => '/Path/to/local/git/repo',
  :branch => 'my-feature-branch'

Then, if it changes I run

bundle exec gem uninstall foo
bundle update foo

But I am not sure everyone needs to run these two steps.

How to set bot's status

Simple way to initiate the message on startup:

bot.on('ready', () => {
    bot.user.setStatus('available')
    bot.user.setPresence({
        game: {
            name: 'with depression',
            type: "STREAMING",
            url: "https://www.twitch.tv/monstercat"
        }
    });
});

You can also just declare it elsewhere after startup, to change the message as needed:

bot.user.setPresence({ game: { name: 'with depression', type: "streaming", url: "https://www.twitch.tv/monstercat"}}); 

Add views below toolbar in CoordinatorLayout

As of Android studio 3.4, You need to put this line in your Layout which holds the RecyclerView.

app:layout_behavior="android.support.design.widget.AppBarLayout$ScrollingViewBehavior"

How to run a .jar in mac?

Make Executable your jar and after that double click on it on Mac OS then it works successfully.

sudo chmod +x filename.jar

Try this, I hope this works.

jQuery: using a variable as a selector

You're thinking too complicated. It's actually just $('#'+openaddress).

Spring Could not Resolve placeholder

My solution was to add a space between the $ and the {.

For example:

@Value("${appclient.port:}")

becomes

@Value("$ {appclient.port:}")

Why Is `Export Default Const` invalid?

The answer shared by Paul is the best one. To expand more,

There can be only one default export per file. Whereas there can be more than one const exports. The default variable can be imported with any name, whereas const variable can be imported with it's particular name.

var message2 = 'I am exported';
export default message2;
export const message = 'I am also exported'

At the imports side we need to import it like this:

import { message } from './test';

or

import message from './test';

With the first import, the const variable is imported whereas, with the second one, the default one will be imported.

How to determine the IP address of a Solaris system

The following shell script gives a nice tabular result of interfaces and IP addresses (excluding the loopback interface) It has been tested on a Solaris box

/usr/sbin/ifconfig -a | awk '/flags/ {printf $1" "} /inet/ {print $2}' | grep -v lo

ce0: 10.106.106.108
ce0:1: 10.106.106.23
ce0:2: 10.106.106.96
ce1: 10.106.106.109

Spring Boot - Cannot determine embedded database driver class for database type NONE

If you want to use embedded H2 database from Spring Boot starter add the below dependency to your pom file.

    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <version>1.3.156</version>
    </dependency>

But as mentioned in comments, the embedded H2 database keeps data in memory and doesn't stores it permanently.

How do you set the EditText keyboard to only consist of numbers on Android?

After several tries, I got it! I'm setting the keyboard values programmatically like this:

myEditText.setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_VARIATION_PASSWORD);

Or if you want you can edit the XML like so:

android: inputType = "numberPassword"

Both configs will display password bullets, so we need to create a custom ClickableSpan class:

private class NumericKeyBoardTransformationMethod extends PasswordTransformationMethod {
    @Override
    public CharSequence getTransformation(CharSequence source, View view) {
        return source;
    }
}

Finally we need to implement it on the EditText in order to display the characters typed.

myEditText.setTransformationMethod(new NumericKeyBoardTransformationMethod());

This is how my keyboard looks like now:

NodeJS - What does "socket hang up" actually mean?

I think worth noting...

I was creating tests for Google APIs. I was intercepting the request with a makeshift server, then forwarding those to the real api. I was attempting to just pass along the headers in the request, but a few headers were causing a problem with express on the other end.

Namely, I had to delete connection, accept, and content-length headers before using the request module to forward along.

let headers = Object.assign({}, req.headers);
delete headers['connection']
delete headers['accept']
delete headers['content-length']
res.end() // We don't need the incoming connection anymore
request({
  method: 'post',
  body: req.body,
  headers: headers,
  json: true,
  url: `http://myapi/${req.url}`
}, (err, _res, body)=>{
  if(err) return done(err);
  // Test my api response here as if Google sent it.
})

Difference between PCDATA and CDATA in DTD

PCDATA - Parsed Character Data

XML parsers normally parse all the text in an XML document.

CDATA - (Unparsed) Character Data

The term CDATA is used about text data that should not be parsed by the XML parser.

Characters like "<" and "&" are illegal in XML elements.

Magento - Retrieve products with a specific attribute value

Almost all Magento Models have a corresponding Collection object that can be used to fetch multiple instances of a Model.

To instantiate a Product collection, do the following

$collection = Mage::getModel('catalog/product')->getCollection();

Products are a Magento EAV style Model, so you'll need to add on any additional attributes that you want to return.

$collection = Mage::getModel('catalog/product')->getCollection();

//fetch name and orig_price into data
$collection->addAttributeToSelect('name');  
$collection->addAttributeToSelect('orig_price');    

There's multiple syntaxes for setting filters on collections. I always use the verbose one below, but you might want to inspect the Magento source for additional ways the filtering methods can be used.

The following shows how to filter by a range of values (greater than AND less than)

$collection = Mage::getModel('catalog/product')->getCollection();
$collection->addAttributeToSelect('name');  
$collection->addAttributeToSelect('orig_price');    

//filter for products whose orig_price is greater than (gt) 100
$collection->addFieldToFilter(array(
    array('attribute'=>'orig_price','gt'=>'100'),
)); 

//AND filter for products whose orig_price is less than (lt) 130
$collection->addFieldToFilter(array(
    array('attribute'=>'orig_price','lt'=>'130'),
));

While this will filter by a name that equals one thing OR another.

$collection = Mage::getModel('catalog/product')->getCollection();
$collection->addAttributeToSelect('name');  
$collection->addAttributeToSelect('orig_price');    

//filter for products who name is equal (eq) to Widget A, or equal (eq) to Widget B
$collection->addFieldToFilter(array(
    array('attribute'=>'name','eq'=>'Widget A'),
    array('attribute'=>'name','eq'=>'Widget B'),        
));

A full list of the supported short conditionals (eq,lt, etc.) can be found in the _getConditionSql method in lib/Varien/Data/Collection/Db.php

Finally, all Magento collections may be iterated over (the base collection class implements on of the the iterator interfaces). This is how you'll grab your products once filters are set.

$collection = Mage::getModel('catalog/product')->getCollection();
$collection->addAttributeToSelect('name');  
$collection->addAttributeToSelect('orig_price');    

//filter for products who name is equal (eq) to Widget A, or equal (eq) to Widget B
$collection->addFieldToFilter(array(
    array('attribute'=>'name','eq'=>'Widget A'),
    array('attribute'=>'name','eq'=>'Widget B'),        
));

foreach ($collection as $product) {
    //var_dump($product);
    var_dump($product->getData());
}

Checking session if empty or not

If It is simple Session you can apply NULL Check directly Session["emp_num"] != null

But if it's a session of a list Item then You need to apply any one of the following option

Option 1:

if (((List<int>)(Session["emp_num"])) != null && (List<int>)Session["emp_num"])).Count > 0)
 {
 //Your Logic here
 }

Option 2:

List<int> val= Session["emp_num"] as List<int>;  //Get the value from Session.

if (val.FirstOrDefault() != null)
 {
 //Your Logic here
 }

How to select all records from one table that do not exist in another table?

Here's what worked best for me.

SELECT *
FROM @T1
EXCEPT
SELECT a.*
FROM @T1 a
JOIN @T2 b ON a.ID = b.ID

This was more than twice as fast as any other method I tried.

I want to exception handle 'list index out of range.'

Handling the exception is the way to go:

try:
    gotdata = dlist[1]
except IndexError:
    gotdata = 'null'

Of course you could also check the len() of dlist; but handling the exception is more intuitive.

What is the "proper" way to cast Hibernate Query.list() to List<Type>?

To answer your question, there is no "proper way" to do that. Now if it's just the warning that bothers you, the best way to avoid its proliferation is to wrap the Query.list() method into a DAO :

public class MyDAO {

    @SuppressWarnings("unchecked")
    public static <T> List<T> list(Query q){
        return q.list();
    }
}

This way you get to use the @SuppressWarnings("unchecked") only once.

Why do we use __init__ in Python classes?

It is just to initialize the instance's variables.

E.g. create a crawler instance with a specific database name (from your example above).

Twitter bootstrap float div right

bootstrap 3 has a class to align the text within a div

<div class="text-right">

will align the text on the right

<div class="pull-right">

will pull to the right all the content not only the text

How to get all key in JSON object (javascript)

var jsonData = { Name: "Ricardo Vasquez", age: "46", Email: "[email protected]" };

for (x in jsonData) {   
  console.log(x +" => "+ jsonData[x]);  
  alert(x +" => "+  jsonData[x]);  
  }

How to enter newline character in Oracle?

According to the Oracle PLSQL language definition, a character literal can contain "any printable character in the character set". https://docs.oracle.com/cd/A97630_01/appdev.920/a96624/02_funds.htm#2876

@Robert Love's answer exhibits a best practice for readable code, but you can also just type in the linefeed character into the code. Here is an example from a Linux terminal using sqlplus:

SQL> set serveroutput on
SQL> begin   
  2  dbms_output.put_line( 'hello' || chr(10) || 'world' );
  3  end;
  4  /
hello
world

PL/SQL procedure successfully completed.

SQL> begin
  2  dbms_output.put_line( 'hello
  3  world' );
  4  end;
  5  /
hello
world

PL/SQL procedure successfully completed.

Instead of the CHR( NN ) function you can also use Unicode literal escape sequences like u'\0085' which I prefer because, well you know we are not living in 1970 anymore. See the equivalent example below:

SQL> begin
  2  dbms_output.put_line( 'hello' || u'\000A' || 'world' );
  3  end;
  4  /
hello
world

PL/SQL procedure successfully completed.

For fair coverage I guess it is worth noting that different operating systems use different characters/character sequences for end of line handling. You've got to have a think about the context in which your program output is going to be viewed or printed, in order to determine whether you are using the right technique.

  • Microsoft Windows: CR/LF or u'\000D\000A'
  • Unix (including Apple MacOS): LF or u'\000A'
  • IBM OS390: NEL or u'\0085'
  • HTML: '<BR>'
  • XHTML: '<br />'
  • etc. etc.

Image overlay on responsive sized images bootstrap

When you specify position:absolute it positions itself to the next-highest element with position:relative. In this case, that's the .project div.

If you give the image's immediate parent div a style of position:relative, the overlay will key to that instead of the div which includes the text. For example: http://jsfiddle.net/7gYUU/1/

 <div class="parent">
    <img src="http://placehold.it/500x500" class="img-responsive"/>
    <div class="fa fa-plus project-overlay"></div>
 </div>

.parent {
   position: relative;
}

How to calculate the difference between two dates using PHP?

I voted for jurka's answer as that's my favorite, but I have a pre-php.5.3 version...

I found myself working on a similar problem - which is how I got to this question in the first place - but just needed a difference in hours. But my function solved this one pretty nicely as well and I don't have anywhere in my own library to keep it where it won't get lost and forgotten, so... hope this is useful to someone.

/**
 *
 * @param DateTime $oDate1
 * @param DateTime $oDate2
 * @return array 
 */
function date_diff_array(DateTime $oDate1, DateTime $oDate2) {
    $aIntervals = array(
        'year'   => 0,
        'month'  => 0,
        'week'   => 0,
        'day'    => 0,
        'hour'   => 0,
        'minute' => 0,
        'second' => 0,
    );

    foreach($aIntervals as $sInterval => &$iInterval) {
        while($oDate1 <= $oDate2){ 
            $oDate1->modify('+1 ' . $sInterval);
            if ($oDate1 > $oDate2) {
                $oDate1->modify('-1 ' . $sInterval);
                break;
            } else {
                $iInterval++;
            }
        }
    }

    return $aIntervals;
}

And the test:

$oDate = new DateTime();
$oDate->modify('+111402189 seconds');
var_dump($oDate);
var_dump(date_diff_array(new DateTime(), $oDate));

And the result:

object(DateTime)[2]
  public 'date' => string '2014-04-29 18:52:51' (length=19)
  public 'timezone_type' => int 3
  public 'timezone' => string 'America/New_York' (length=16)

array
  'year'   => int 3
  'month'  => int 6
  'week'   => int 1
  'day'    => int 4
  'hour'   => int 9
  'minute' => int 3
  'second' => int 8

I got the original idea from here, which I modified for my uses (and I hope my modification will show on that page as well).

You can very easily remove intervals you don't want (say "week") by removing them from the $aIntervals array, or maybe adding an $aExclude parameter, or just filter them out when you output the string.

Get path to execution directory of Windows Forms application

System.Windows.Forms.Application.StartupPath will solve your problem, I think

C# ASP.NET Single Sign-On Implementation

There are multiple options to implement SSO for a .NET application.

Check out the following tutorials online:

Basics of Single Sign on, July 2012

http://www.codeproject.com/Articles/429166/Basics-of-Single-Sign-on-SSO

GaryMcAllisterOnline: ASP.NET MVC 4, ADFS 2.0 and 3rd party STS integration (IdentityServer2), Jan 2013

http://garymcallisteronline.blogspot.com/2013/01/aspnet-mvc-4-adfs-20-and-3rd-party-sts.html

The first one uses ASP.NET Web Forms, while the second one uses ASP.NET MVC4.

If your requirements allow you to use a third-party solution, also consider OpenID. There's an open source library called DotNetOpenAuth.

For further information, read MSDN blog post Integrate OpenAuth/OpenID with your existing ASP.NET application using Universal Providers.

Hope this helps!

How to 'restart' an android application programmatically

Checkout intent properties like no history , clear back stack etc ... Intent.setFlags

Intent mStartActivity = new Intent(HomeActivity.this, SplashScreen.class);
int mPendingIntentId = 123456;
PendingIntent mPendingIntent = PendingIntent.getActivity(HomeActivity.this, mPendingIntentId, mStartActivity,
PendingIntent.FLAG_CANCEL_CURRENT);
AlarmManager mgr = (AlarmManager) HomeActivity.this.getSystemService(Context.ALARM_SERVICE);
mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 100, mPendingIntent);
System.exit(0);

Disallow Twitter Bootstrap modal window from closing

In case anyone comes here from Google trying to figure out how to prevent someone from closing a modal, don't forget that there's also a close button on the top right of the modal that needs to be removed.

I used some CSS to hide it:

#Modal .modal-header button.close {
    visibility: hidden;
}

Note that using "display: none;" gets overwritten when the modal is created, so don't use that.

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

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

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

python-dev installation error: ImportError: No module named apt_pkg

This happened to me on Ubuntu 18.04.2 after I tried to install Python3.7 from the deadsnakes repo.

Solution was this

1) cd /usr/lib/python3/dist-packages/

2) sudo ln -s apt_pkg.cpython-36m-x86_64-linux-gnu.so apt_pkg.so

adb command not found

In my case, I was in the platform-tools directory but was using command in the wrong way:

adb install

instead of the right way:

./adb install

Git update submodules recursively

In recent Git (I'm using v2.15.1), the following will merge upstream submodule changes into the submodules recursively:

git submodule update --recursive --remote --merge

You may add --init to initialize any uninitialized submodules and use --rebase if you want to rebase instead of merge.

You need to commit the changes afterwards:

git add . && git commit -m 'Update submodules to latest revisions'

Angular2 Error: There is no directive with "exportAs" set to "ngForm"

The correct way of use forms now in Angular2 is:

<form  (ngSubmit)="onSubmit()">

        <label>Username:</label>
        <input type="text" class="form-control"   [(ngModel)]="user.username" name="username" #username="ngModel" required />

        <label>Contraseña:</label>
        <input type="password" class="form-control"  [(ngModel)]="user.password" name="password" #password="ngModel" required />


    <input type="submit" value="Entrar" class="btn btn-primary"/>

</form>

The old way doesn't works anymore

How to print a list in Python "nicely"

from pprint import pprint
pprint(the_list)

CSS @font-face not working with Firefox, but working with Chrome and IE

May be its not because of your code, Its because of your Firefox configuration.

Try this from Tool bar Western to Unicode

View > Text Encoding > Unicode

Proper Linq where clauses

Looking under the hood, the two statements will be transformed into different query representations. Depending on the QueryProvider of Collection, this might be optimized away or not.

When this is a linq-to-object call, multiple where clauses will lead to a chain of IEnumerables that read from each other. Using the single-clause form will help performance here.

When the underlying provider translates it into a SQL statement, the chances are good that both variants will create the same statement.

Find row number of matching value

For your first method change ws.Range("A") to ws.Range("A:A") which will search the entirety of column a, like so:

Sub Find_Bingo()

        Dim wb As Workbook
        Dim ws As Worksheet
        Dim FoundCell As Range
        Set wb = ActiveWorkbook
        Set ws = ActiveSheet

            Const WHAT_TO_FIND As String = "Bingo"

            Set FoundCell = ws.Range("A:A").Find(What:=WHAT_TO_FIND)
            If Not FoundCell Is Nothing Then
                MsgBox (WHAT_TO_FIND & " found in row: " & FoundCell.Row)
            Else
                MsgBox (WHAT_TO_FIND & " not found")
            End If
End Sub

For your second method, you are using Bingo as a variable instead of a string literal. This is a good example of why I add Option Explicit to the top of all of my code modules, as when you try to run the code it will direct you to this "variable" which is undefined and not intended to be a variable at all.

Additionally, when you are using With...End With you need a period . before you reference Cells, so Cells should be .Cells. This mimics the normal qualifying behavior (i.e. Sheet1.Cells.Find..)

Change Bingo to "Bingo" and change Cells to .Cells

With Sheet1
        Set FoundCell = .Cells.Find(What:="Bingo", After:=.Cells(1, 1), _
        LookIn:=xlValues, lookat:=xlPart, SearchOrder:=xlByRows, _
        SearchDirection:=xlNext, MatchCase:=False, SearchFormat:=False)
    End With

If Not FoundCell Is Nothing Then
        MsgBox ("""Bingo"" found in row " & FoundCell.Row)
Else
        MsgBox ("Bingo not found")
End If

Update

In my

With Sheet1
    .....
End With

The Sheet1 refers to a worksheet's code name, not the name of the worksheet itself. For example, say I open a new blank Excel workbook. The default worksheet is just Sheet1. I can refer to that in code either with the code name of Sheet1 or I can refer to it with the index of Sheets("Sheet1"). The advantage to using a codename is that it does not change if you change the name of the worksheet.

Continuing this example, let's say I renamed Sheet1 to Data. Using Sheet1 would continue to work, as the code name doesn't change, but now using Sheets("Sheet1") would return an error and that syntax must be updated to the new name of the sheet, so it would need to be Sheets("Data").

In the VB Editor you would see something like this:

code object explorer example

Notice how, even though I changed the name to Data, there is still a Sheet1 to the left. That is what I mean by codename.

The Data worksheet can be referenced in two ways:

Debug.Print Sheet1.Name
Debug.Print Sheets("Data").Name

Both should return Data

More discussion on worksheet code names can be found here.

Crop image to specified size and picture location

You would need to do something like this. I am typing this off the top of my head, so this may not be 100% correct.

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, 640, 360, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst); CGColorSpaceRelease(colorSpace);  CGContextDrawImage(context, CGRectMake(0,-160,640,360), cgImgFromAVCaptureSession);  CGImageRef image = CGBitmapContextCreateImage(context); UIImage* myCroppedImg = [UIImage imageWithCGImage:image]; CGContextRelease(context);       

PHP CSV string to array

Slightly shorter version, without unnecessary second variable:

$csv = <<<'ENDLIST'
"12345","Computers","Acer","4","Varta","5.93","1","0.04","27-05-2013"
"12346","Computers","Acer","5","Decra","5.94","1","0.04","27-05-2013"
ENDLIST;

$arr = explode("\n", $csv);
foreach ($arr as &$line) {
  $line = str_getcsv($line);
}

How can I set the 'backend' in matplotlib in Python?

This can also be set in the configuration file matplotlibrc (as explained in the error message), for instance:

# The default backend; one of GTK GTKAgg GTKCairo GTK3Agg GTK3Cairo
# CocoaAgg MacOSX Qt4Agg Qt5Agg TkAgg WX WXAgg Agg Cairo GDK PS PDF SVG
backend : Agg

That way, the backend does not need to be hardcoded if the code is shared with other people. For more information, check the documentation.

cin and getline skipping input

I faced this issue, and resolved this issue using getchar() to catch the ('\n') new char

angularjs directive call function specified in attribute and pass an argument to it

Marko's solution works well.

To contrast with recommended Angular way (as shown by treeface's plunkr) is to use a callback expression which does not require defining the expressionHandler. In marko's example change:

In template

<div my-method="theMethodToBeCalled(myParam)"></div>

In directive link function

$(element).click(function( e, rowid ) {
  scope.method({myParam: id});
});

This does have one disadvantage compared to marko's solution - on first load theMethodToBeCalled function will be invoked with myParam === undefined.

A working exampe can be found at @treeface Plunker

Get ALL User Friends Using Facebook Graph API - Android

In v2.0 of the Graph API, calling /me/friends returns the person's friends who also use the app.

In addition, in v2.0, you must request the user_friends permission from each user. user_friends is no longer included by default in every login. Each user must grant the user_friends permission in order to appear in the response to /me/friends. See the Facebook upgrade guide for more detailed information, or review the summary below.

The /me/friendlists endpoint and user_friendlists permission are not what you're after. This endpoint does not return the users friends - its lets you access the lists a person has made to organize their friends. It does not return the friends in each of these lists. This API and permission is useful to allow you to render a custom privacy selector when giving people the opportunity to publish back to Facebook.

If you want to access a list of non-app-using friends, there are two options:

  1. If you want to let your people tag their friends in stories that they publish to Facebook using your App, you can use the /me/taggable_friends API. Use of this endpoint requires review by Facebook and should only be used for the case where you're rendering a list of friends in order to let the user tag them in a post.

  2. If your App is a Game AND your Game supports Facebook Canvas, you can use the /me/invitable_friends endpoint in order to render a custom invite dialog, then pass the tokens returned by this API to the standard Requests Dialog.

In other cases, apps are no longer able to retrieve the full list of a user's friends (only those friends who have specifically authorized your app using the user_friends permission).

For apps wanting allow people to invite friends to use an app, you can still use the Send Dialog on Web or the new Message Dialog on iOS and Android.

How to find the extension of a file in C#?

I'm not sure if this is what you want but:

Directory.GetFiles(@"c:\mydir", "*.flv");

Or:

Path.GetExtension(@"c:\test.flv")

How to get parameters from the URL with JSP

In a GET request, the request parameters are taken from the query string (the data following the question mark on the URL). For example, the URL http://hostname.com?p1=v1&p2=v2 contains two request parameters - - p1 and p2. In a POST request, the request parameters are taken from both query string and the posted data which is encoded in the body of the request.

This example demonstrates how to include the value of a request parameter in the generated output:

Hello <b><%= request.getParameter("name") %></b>!

If the page was accessed with the URL:

http://hostname.com/mywebapp/mypage.jsp?name=John+Smith

the resulting output would be:

Hello <b>John Smith</b>!

If name is not specified on the query string, the output would be:

Hello <b>null</b>!

This example uses the value of a query parameter in a scriptlet:

<%
    if (request.getParameter("name") == null) {
        out.println("Please enter your name.");
    } else {
        out.println("Hello <b>"+request. getParameter("name")+"</b>!");
    }
%>

Firebase (FCM) how to get token

The FirebaseInstanceId.getInstance().getInstanceId() is deprecated. Based on firebase document, you can retrieve the current registration token using following code:

FirebaseMessaging.getInstance().getToken()
    .addOnCompleteListener(new OnCompleteListener<String>() {
        @Override
        public void onComplete(@NonNull Task<String> task) {
          if (!task.isSuccessful()) {
            Log.w(TAG, "Fetching FCM registration token failed", task.getException());
            return;
          }

          // Get new FCM registration token
          String token = task.getResult();

          // Log and toast
          String msg = getString(R.string.msg_token_fmt, token);
          Log.d(TAG, msg);
          Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
        }
    });

Determine whether a Access checkbox is checked or not

Checkboxes are a control type designed for one purpose: to ensure valid entry of Boolean values.

In Access, there are two types:

  1. 2-state -- can be checked or unchecked, but not Null. Values are True (checked) or False (unchecked). In Access and VBA, the value of True is -1 and the value of False is 0. For portability with environments that use 1 for True, you can always test for False or Not False, since False is the value 0 for all environments I know of.

  2. 3-state -- like the 2-state, but can be Null. Clicking it cycles through True/False/Null. This is for binding to an integer field that allows Nulls. It is of no use with a Boolean field, since it can never be Null.

Minor quibble with the answers:

There is almost never a need to use the .Value property of an Access control, as it's the default property. These two are equivalent:

  ?Me!MyCheckBox.Value
  ?Me!MyCheckBox

The only gotcha here is that it's important to be careful that you don't create implicit references when testing the value of a checkbox. Instead of this:

  If Me!MyCheckBox Then

...write one of these options:

  If (Me!MyCheckBox) Then  ' forces evaluation of the control

  If Me!MyCheckBox = True Then

  If (Me!MyCheckBox = True) Then

  If (Me!MyCheckBox = Not False) Then

Likewise, when writing subroutines or functions that get values from a Boolean control, always declare your Boolean parameters as ByVal unless you actually want to manipulate the control. In that case, your parameter's data type should be an Access control and not a Boolean value. Anything else runs the risk of implicit references.

Last of all, if you set the value of a checkbox in code, you can actually set it to any number, not just 0 and -1, but any number other than 0 is treated as True (because it's Not False). While you might use that kind of thing in an HTML form, it's not proper UI design for an Access app, as there's no way for the user to be able to see what value is actually be stored in the control, which defeats the purpose of choosing it for editing your data.

Auto code completion on Eclipse

Steps:

  • In Eclipse, open the code auto completion box from first letter
  • Go to >> Window >> preference >> [ Java c++ php ... ] >> Editor >> Auto activation triggers for...
  • Add the character SPACE by just putting your cursor inside and box and push the space key..

All the commands and variables which begin with that letter are now going to appear

jQuery adding 2 numbers from input fields

Use this code for adding two numbers by using jquery

<!DOCTYPE html>
    <html lang="en-US">
    <head>
        <title>HTML Tutorial</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <meta charset="windows-1252">
    <script>

    $(document).ready(function(){
        $("#submit").on("click", function(){
        var a = parseInt($('#a').val());
        var b = parseInt($('#b').val());
           var sum = a + b;
            alert(sum);
        })
    })
    </script>
    </head>
    <body>
       <input type="text" id="a" name="option">
       <input type="text" id="b" name="task">
    <input id="submit" type="button" value="press me">

    </body>

    </html>

OR is not supported with CASE Statement in SQL Server

There are already a lot of answers with respect to CASE. I will explain when and how to use CASE.

You can use CASE expressions anywhere in the SQL queries. CASE expressions can be used within the SELECT statement, WHERE clauses, Order by clause, HAVING clauses, Insert, UPDATE and DELETE statements.

A CASE expression has the following two formats:

  1. Simple CASE expression

    CASE expression
    WHEN expression1 THEN Result1
    WHEN expression2 THEN Result2
    ELSE ResultN
    END
    

    This compares an expression to a set of simple expressions to find the result. This expression compares an expression to the expression in each WHEN clause for equivalency. If the expression within the WHEN clause is matched, the expression in the THEN clause will be returned.

    This is where the OP's question is falling. 22978 OR 23218 OR 23219 will not get a value equal to the expression i.e. ebv.db_no. That's why it is giving an error. The data types of input_expression and each when_expression must be the same or must be an implicit conversion.

  2. Searched CASE expressions

    CASE
    WHEN Boolean_expression1 THEN Result1
    WHEN Boolean_expression2 THEN Result2
    ELSE ResultN
    END
    

    This expression evaluates a set of boolean expressions to find the result. This expression allows comparison operators, and logical operators AND/OR with in each Boolean expression.

1.SELECT statement with CASE expressions

--Simple CASE expression: 
SELECT FirstName, State=(CASE StateCode
 WHEN 'MP' THEN 'Madhya Pradesh' 
 WHEN 'UP' THEN 'Uttar Pradesh' 
 WHEN 'DL' THEN 'Delhi' 
 ELSE NULL 
 END), PayRate
FROM dbo.Customer

-- Searched CASE expression:
SELECT FirstName,State=(CASE 
 WHEN StateCode = 'MP' THEN 'Madhya Pradesh' 
 WHEN StateCode = 'UP' THEN 'Uttar Pradesh' 
 WHEN StateCode = 'DL' THEN 'Delhi' 
 ELSE NULL 
 END), PayRate
FROM dbo.Customer

2.Update statement with CASE expression

-- Simple CASE expression: 
UPDATE Customer 
SET StateCode = CASE StateCode
 WHEN 'MP' THEN 'Madhya Pradesh' 
 WHEN 'UP' THEN 'Uttar Pradesh' 
 WHEN 'DL' THEN 'Delhi' 
 ELSE NULL 
 END 

-- Simple CASE expression: 
UPDATE Customer 
SET StateCode = CASE 
 WHEN StateCode = 'MP' THEN 'Madhya Pradesh' 
 WHEN StateCode = 'UP' THEN 'Uttar Pradesh' 
 WHEN StateCode = 'DL' THEN 'Delhi' 
 ELSE NULL 
 END 

3.ORDER BY clause with CASE expressions

-- Simple CASE expression: 
SELECT * FROM dbo.Customer
ORDER BY 
 CASE Gender WHEN 'M' THEN FirstName END Desc,
 CASE Gender WHEN 'F' THEN LastName END ASC

-- Searched CASE expression: 
SELECT * FROM dbo.Customer
ORDER BY 
 CASE WHEN Gender='M' THEN FirstName END Desc,
 CASE WHEN Gender='F' THEN LastName END ASC

4.Having Clause with CASE expression

-- Simple CASE expression: 
SELECT FirstName ,StateCode,Gender, Total=MAX(PayRate)
FROM dbo.Customer
GROUP BY StateCode,Gender,FirstName
HAVING (MAX(CASE Gender WHEN 'M' 
 THEN PayRate 
 ELSE NULL END) > 180.00
 OR MAX(CASE Gender WHEN 'F' 
 THEN PayRate 
 ELSE NULL END) > 170.00)

-- Searched CASE expression: 
SELECT FirstName ,StateCode,Gender, Total=MAX(PayRate)
FROM dbo.Customer
GROUP BY StateCode,Gender,FirstName
HAVING (MAX(CASE WHEN Gender = 'M' 
 THEN PayRate 
 ELSE NULL END) > 180.00
 OR MAX(CASE WHEN Gender = 'F' 
 THEN PayRate 
 ELSE NULL END) > 170.00)

Hope this use cases will help someone in future.

Source

powershell mouse move does not prevent idle mode

I created a PS script to check idle time and jiggle the mouse to prevent the screensaver.

There are two parameters you can control how it works.

$checkIntervalInSeconds : the interval in seconds to check if the idle time exceeds the limit

$preventIdleLimitInSeconds : the idle time limit in seconds. If the idle time exceeds the idle time limit, jiggle the mouse to prevent the screensaver

Here we go. Save the script in preventIdle.ps1. For preventing the 4-min screensaver, I set $checkIntervalInSeconds = 30 and $preventIdleLimitInSeconds = 180.

Add-Type @'
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace PInvoke.Win32 {

    public static class UserInput {

        [DllImport("user32.dll", SetLastError=false)]
        private static extern bool GetLastInputInfo(ref LASTINPUTINFO plii);

        [StructLayout(LayoutKind.Sequential)]
        private struct LASTINPUTINFO {
            public uint cbSize;
            public int dwTime;
        }

        public static DateTime LastInput {
            get {
                DateTime bootTime = DateTime.UtcNow.AddMilliseconds(-Environment.TickCount);
                DateTime lastInput = bootTime.AddMilliseconds(LastInputTicks);
                return lastInput;
            }
        }

        public static TimeSpan IdleTime {
            get {
                return DateTime.UtcNow.Subtract(LastInput);
            }
        }

        public static double IdleSeconds {
            get {
                return IdleTime.TotalSeconds;
            }
        }

        public static int LastInputTicks {
            get {
                LASTINPUTINFO lii = new LASTINPUTINFO();
                lii.cbSize = (uint)Marshal.SizeOf(typeof(LASTINPUTINFO));
                GetLastInputInfo(ref lii);
                return lii.dwTime;
            }
        }
    }
}
'@

Add-Type @'
using System;
using System.Runtime.InteropServices;

namespace MouseMover
{
    public class MouseSimulator
    {
        [DllImport("user32.dll", SetLastError = true)]
        static extern uint SendInput(uint nInputs, ref INPUT pInputs, int cbSize);
        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool GetCursorPos(out POINT lpPoint);

        [StructLayout(LayoutKind.Sequential)]
        struct INPUT
        {
            public SendInputEventType type;
            public MouseKeybdhardwareInputUnion mkhi;
        }
        [StructLayout(LayoutKind.Explicit)]
        struct MouseKeybdhardwareInputUnion
        {
            [FieldOffset(0)]
            public MouseInputData mi;

            [FieldOffset(0)]
            public KEYBDINPUT ki;

            [FieldOffset(0)]
            public HARDWAREINPUT hi;
        }
        [StructLayout(LayoutKind.Sequential)]
        struct KEYBDINPUT
        {
            public ushort wVk;
            public ushort wScan;
            public uint dwFlags;
            public uint time;
            public IntPtr dwExtraInfo;
        }
        [StructLayout(LayoutKind.Sequential)]
        struct HARDWAREINPUT
        {
            public int uMsg;
            public short wParamL;
            public short wParamH;
        }
        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            public int X;
            public int Y;

            public POINT(int x, int y)
            {
                this.X = x;
                this.Y = y;
            }
        }
        struct MouseInputData
        {
            public int dx;
            public int dy;
            public uint mouseData;
            public MouseEventFlags dwFlags;
            public uint time;
            public IntPtr dwExtraInfo;
        }

        [Flags]
        enum MouseEventFlags : uint
        {
            MOUSEEVENTF_MOVE = 0x0001
        }
        enum SendInputEventType : int
        {
            InputMouse
        }
        public static void MoveMouseBy(int x, int y) {
            INPUT mouseInput = new INPUT();
            mouseInput.type = SendInputEventType.InputMouse;
            mouseInput.mkhi.mi.dwFlags = MouseEventFlags.MOUSEEVENTF_MOVE;
            mouseInput.mkhi.mi.dx = x;
            mouseInput.mkhi.mi.dy = y;
            SendInput(1, ref mouseInput, Marshal.SizeOf(mouseInput));
        }
    }
}
'@

$checkIntervalInSeconds = 30
$preventIdleLimitInSeconds = 180

while($True) {
    if (([PInvoke.Win32.UserInput]::IdleSeconds -ge $preventIdleLimitInSeconds)) {
        [MouseMover.MouseSimulator]::MoveMouseBy(10,0)
        [MouseMover.MouseSimulator]::MoveMouseBy(-10,0)
    }
    Start-Sleep -Seconds $checkIntervalInSeconds
}

Then, open Windows PowerShell and run

powershell -ExecutionPolicy ByPass -File C:\SCRIPT-DIRECTORY-PATH\preventIdle.ps1

How to connect to SQL Server from command prompt with Windows authentication

Try This :

--Default Instance

SQLCMD -S SERVERNAME -E

--OR
--Named Instance

SQLCMD -S SERVERNAME\INSTANCENAME -E

--OR

SQLCMD -S SERVERNAME\INSTANCENAME,1919 -E

More details can be found here

What equivalents are there to TortoiseSVN, on Mac OSX?

My previous version of this answer had links, that kept becoming dead.
So, I've pointed it to the internet archive to preserve the original answer.

Subversion client releases for Windows and Macintosh

Wiki - Subversion clients comparison table

How do I concatenate strings and variables in PowerShell?

One way is:

Write-Host "$($assoc.Id)  -  $($assoc.Name)  -  $($assoc.Owner)"

Another one is:

Write-Host  ("{0}  -  {1}  -  {2}" -f $assoc.Id,$assoc.Name,$assoc.Owner )

Or just (but I don't like it ;) ):

Write-Host $assoc.Id  "  -  "   $assoc.Name  "  -  "  $assoc.Owner

How to retrieve the hash for the current commit in Git?

Here is one-liner in Bash shell using direct read from git files:

(head=($(<.git/HEAD)); cat .git/${head[1]})

You need to run above command in your git root folder.

This method can be useful when you've repository files, but git command has been not installed.

If won't work, check in .git/refs/heads folder what kind of heads do you have present.

How to convert milliseconds into a readable date?

No, you'll need to do it manually.

_x000D_
_x000D_
function prettyDate(date) {_x000D_
  var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',_x000D_
                'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];_x000D_
_x000D_
  return months[date.getUTCMonth()] + ' ' + date.getUTCDate() + ', ' + date.getUTCFullYear();_x000D_
}_x000D_
_x000D_
console.log(prettyDate(new Date(1324339200000)));
_x000D_
_x000D_
_x000D_

Why is my locally-created script not allowed to run under the RemoteSigned execution policy?

What works for me was right-click on the .ps1 file and then properties. Click the "UNBLOCK" button. Works great fir me after spending hours trying to change the policies.

What are the obj and bin folders (created by Visual Studio) used for?

One interesting fact about the obj directory: If you have publishing set up in a web project, the files that will be published are staged to obj\Release\Package\PackageTmp. If you want to publish the files yourself rather than use the integrated VS feature, you can grab the files that you actually need to deploy here, rather than pick through all the digital debris in the bin directory.

Custom Input[type="submit"] style not working with jquerymobile button

I'm assume you cannot get css working for your button using anchor tag. So you need to override the css styles which are being overwritten by other elements using !important property.

HTML

<a href="#" class="selected_btn" data-role="button">Button name</a>

CSS

.selected_btn
{
    border:1px solid red;
    text-decoration:none;
    font-family:helvetica;
    color:red !important;            
    background:url('http://www.lessardstephens.com/layout/images/slideshow_big.png') repeat-x;
}

Here is the demo

SQL providerName in web.config

System.Data.SqlClient is the .NET Framework Data Provider for SQL Server. ie .NET library for SQL Server.

I don't know where providerName=SqlServer comes from. Could you be getting this confused with the provider keyword in your connection string? (I know I was :) )

In the web.config you should have the System.Data.SqlClient as the value of the providerName attribute. It is the .NET Framework Data Provider you are using.

<connectionStrings>
   <add 
      name="LocalSqlServer" 
      connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true" 
      providerName="System.Data.SqlClient"
   />
</connectionStrings>

See http://msdn.microsoft.com/en-US/library/htw9h4z3(v=VS.80).aspx

What do the terms "CPU bound" and "I/O bound" mean?

When your program is waiting for I/O (ie. a disk read/write or network read/write etc), the CPU is free to do other tasks even if your program is stopped. The speed of your program will mostly depend on how fast that IO can happen, and if you want to speed it up you will need to speed up the I/O.

If your program is running lots of program instructions and not waiting for I/O, then it is said to be CPU bound. Speeding up the CPU will make the program run faster.

In either case, the key to speeding up the program might not be to speed up the hardware, but to optimize the program to reduce the amount of IO or CPU it needs, or to have it do I/O while it also does CPU intensive stuff.

OS X Terminal shortcut: Jump to beginning/end of line

in iterm2

fn + leftArraw or fn + rightArrow

this worked for me

Encoding as Base64 in Java

Use Java 8's never-too-late-to-join-in-the-fun class: java.util.Base64

new String(Base64.getEncoder().encode(bytes));

How To Use DateTimePicker In WPF?

Please Note: The following answer only applied to WPF under the 3.5 Framework as NET 4.0 runtime has it's own datetime control.

By default WPF 3.5 does not come with a date time picker like winforms.

However a date picker has been added in the WPF tool kit produced by Microsoft which can be downloaded here. I guess it will become part of the framework in a future release.

It is simple to add a reference to the WPFToolkit.dll, see it in the tool box and distribute with your application by following the instructions on the website.

Before this was available other people had created 3rd party pickers (which you may prefer) or alternatively used the less ideal solution of using the winforms control in a WPF application.

Update: This so question is very similar this one which also has a link to a walk through for the datepicker along with other links.

enumerate() for dictionary in python

You may find it useful to include index inside key:

d = {'a': 1, 'b': 2}
d = {(i, k): v for i, (k, v) in enumerate(d.items())}

Output:

{(0, 'a'): True, (1, 'b'): False}

Change a column type from Date to DateTime during ROR migration

Also, if you're using Rails 3 or newer you don't have to use the up and down methods. You can just use change:

class ChangeFormatInMyTable < ActiveRecord::Migration
  def change
    change_column :my_table, :my_column, :my_new_type
  end
end

How can I get the data type of a variable in C#?

Just hold cursor over member you interested in, and see tooltip - it will show memeber's type:

enter image description here

Bypass popup blocker on window.open when JQuery event.preventDefault() is set

var url = window.open("", "_blank");
url.location = "url";

this worked for me.

Execute external program

borrowed this shamely from here

Process process = new ProcessBuilder("C:\\PathToExe\\MyExe.exe","param1","param2").start();
InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;

System.out.printf("Output of running %s is:", Arrays.toString(args));

while ((line = br.readLine()) != null) {
  System.out.println(line);
}

More information here

Other issues on how to pass commands here and here

Get querystring from URL using jQuery

From: http://jquery-howto.blogspot.com/2009/09/get-url-parameters-values-with-jquery.html

This is what you need :)

The following code will return a JavaScript Object containing the URL parameters:

// Read a page's GET URL variables and return them as an associative array.
function getUrlVars()
{
    var vars = [], hash;
    var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
    for(var i = 0; i < hashes.length; i++)
    {
        hash = hashes[i].split('=');
        vars.push(hash[0]);
        vars[hash[0]] = hash[1];
    }
    return vars;
}

For example, if you have the URL:

http://www.example.com/?me=myValue&name2=SomeOtherValue

This code will return:

{
    "me"    : "myValue",
    "name2" : "SomeOtherValue"
}

and you can do:

var me = getUrlVars()["me"];
var name2 = getUrlVars()["name2"];

NoClassDefFoundError on Maven dependency

For some reason, the lib is present while compiling, but missing while running.

My situation is, two versions of one lib conflict.

For example, A depends on B and C, while B depends on D:1.0, C depends on D:1.1, maven may just import D:1.0. If A uses one class which is in D:1.1 but not in D:1.0, a NoClassDefFoundError will be throwed.

If you are in this situation too, you need to resolve the dependency conflict.

How to check if array element exists or not in javascript?

If you are looking for some thing like this.

Here is the following snippetr

_x000D_
_x000D_
var demoArray = ['A','B','C','D'];_x000D_
var ArrayIndexValue = 2;_x000D_
if(demoArray.includes(ArrayIndexValue)){_x000D_
alert("value exists");_x000D_
   //Array index exists_x000D_
}else{_x000D_
alert("does not exist");_x000D_
   //Array Index does not Exists_x000D_
}
_x000D_
_x000D_
_x000D_

"com.jcraft.jsch.JSchException: Auth fail" with working passwords

Try to add auth method explicitly as below, because sometimes it is required:

session.setConfig("PreferredAuthentications", "password");

How to install mod_ssl for Apache httpd?

I used:

sudo yum install mod24_ssl

and it worked in my Amazon Linux AMI.

How do I remove the last comma from a string using PHP?

Try:

$string = "'name', 'name2', 'name3',";
$string = rtrim($string,',');

How to get english language word database?

You may check *spell en-GB dictionary used by Mozilla, OpenOffice, plenty of other software.

Set background colour of cell to RGB value of data in cell

You can use VBA - something like

Range("A1:A6").Interior.Color = RGB(127,187,199)

Just pass in the cell value.

Converting time stamps in excel to dates

If your file is really big try to use following formula: =A1 / 86400 + 25569

A1 should be replaced to what your need. Should work faster than =(((COLUMN_ID_HERE/60)/60)/24)+DATE(1970,1,1) cause of less number of calculations needed.

Is it possible to iterate through JSONArray?

You can use the opt(int) method and use a classical for loop.

Dropdownlist validation in Asp.net Using Required field validator

Add InitialValue="0" in Required field validator tag

 <asp:RequiredFieldValidator InitialValue="-1" ID="Req_ID"
      Display="Dynamic" ValidationGroup="g1" runat="server"
      ControlToValidate="ControlID"
      InitialValue="0" ErrorMessage="ErrorMessage">
 </asp:RequiredFieldValidator>

Run react-native on android emulator

I had similar issue running emulator from android studio everytime, or on a physical device. Instead, you can quickly run android emulator from command line,

android avd

Once the emulator is running, you can check with adb devices if the emulator shows up. Then you can simply use react-native run-android to run the app on the emulator.

Make sure you've platform tools installed to be able to use adb. Or you can use

brew install android-platform-tools

How do I show the changes which have been staged?

The --cached didn't work for me, ... where, inspired by git log

git diff origin/<branch>..<branch> did.

Add a summary row with totals

If you are on SQL Server 2008 or later version, you can use the ROLLUP() GROUP BY function:

SELECT
  Type = ISNULL(Type, 'Total'),
  TotalSales = SUM(TotalSales)
FROM atable
GROUP BY ROLLUP(Type)
;

This assumes that the Type column cannot have NULLs and so the NULL in this query would indicate the rollup row, the one with the grand total. However, if the Type column can have NULLs of its own, the more proper type of accounting for the total row would be like in @Declan_K's answer, i.e. using the GROUPING() function:

SELECT
  Type = CASE GROUPING(Type) WHEN 1 THEN 'Total' ELSE Type END,
  TotalSales = SUM(TotalSales)
FROM atable
GROUP BY ROLLUP(Type)
;

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

SWIFT4 - Easy and elegant way of decoding JSON strings to Struct.

First step - encode String to Data with .utf8 encoding.

Than decode your Data to YourDataStruct.

struct YourDataStruct: Codable {

let type, id: String

init(_ json: String, using encoding: String.Encoding = .utf8) throws {
    guard let data = json.data(using: encoding) else {
        throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
    }
    try self.init(data: data)
}

init(data: Data) throws {
    self = try JSONDecoder().decode(YourDataStruct.self, from: data)
}                                                                      
}

do { let successResponse = try WSDeleteDialogsResponse(response) }
} catch {}

Convert json to a C# array?

using Newtonsoft.Json;

Install this class in package console This class works fine in all .NET Versions, for example in my project: I have DNX 4.5.1 and DNX CORE 5.0 and everything works.

Firstly before JSON deserialization, you need to declare a class to read normally and store some data somewhere This is my class:

public class ToDoItem
{
    public string text { get; set; }
    public string complete { get; set; }
    public string delete { get; set; }
    public string username { get; set; }
    public string user_password { get; set; }
    public string eventID { get; set; }
}

In HttpContent section where you requesting data by GET request for example:

HttpContent content = response.Content;
string mycontent = await content.ReadAsStringAsync();
//deserialization in items
ToDoItem[] items = JsonConvert.DeserializeObject<ToDoItem[]>(mycontent);

Mod in Java produces negative numbers

If you need n % m then:

int i = (n < 0) ? (m - (abs(n) % m) ) %m : (n % m);

mathematical explanation:

n = -1 * abs(n)
-> n % m = (-1 * abs(n) ) % m
-> (-1 * (abs(n) % m) ) % m
-> m - (abs(n) % m))

How can I use grep to show just filenames on Linux?

From the grep(1) man page:

  -l, --files-with-matches
          Suppress  normal  output;  instead  print the name of each input
          file from which output would normally have  been  printed.   The
          scanning  will  stop  on  the  first match.  (-l is specified by
          POSIX.)

Create instance of generic type whose constructor requires a parameter?

You can do by using reflection:

public void AddFruit<T>()where T: BaseFruit
{
  ConstructorInfo constructor = typeof(T).GetConstructor(new Type[] { typeof(int) });
  if (constructor == null)
  {
    throw new InvalidOperationException("Type " + typeof(T).Name + " does not contain an appropriate constructor");
  }
  BaseFruit fruit = constructor.Invoke(new object[] { (int)150 }) as BaseFruit;
  fruit.Enlist(fruitManager);
}

EDIT: Added constructor == null check.

EDIT: A faster variant using a cache:

public void AddFruit<T>()where T: BaseFruit
{
  var constructor = FruitCompany<T>.constructor;
  if (constructor == null)
  {
    throw new InvalidOperationException("Type " + typeof(T).Name + " does not contain an appropriate constructor");
  }
  var fruit = constructor.Invoke(new object[] { (int)150 }) as BaseFruit;
  fruit.Enlist(fruitManager);
}
private static class FruitCompany<T>
{
  public static readonly ConstructorInfo constructor = typeof(T).GetConstructor(new Type[] { typeof(int) });
}

pass array to method Java

There is an important point of arrays that is often not taught or missed in java classes. When arrays are passed to a function, then another pointer is created to the same array ( the same pointer is never passed ). You can manipulate the array using both the pointers, but once you assign the second pointer to a new array in the called method and return back by void to calling function, then the original pointer still remains unchanged.

You can directly run the code here : https://www.compilejava.net/

import java.util.Arrays;

public class HelloWorld
{
    public static void main(String[] args)
    {
        int Main_Array[] = {20,19,18,4,16,15,14,4,12,11,9};
        Demo1.Demo1(Main_Array);
        // THE POINTER Main_Array IS NOT PASSED TO Demo1
        // A DIFFERENT POINTER TO THE SAME LOCATION OF Main_Array IS PASSED TO Demo1

        System.out.println("Main_Array = "+Arrays.toString(Main_Array));
        // outputs : Main_Array = [20, 19, 18, 4, 16, 15, 14, 4, 12, 11, 9]
        // Since Main_Array points to the original location,
        // I cannot access the results of Demo1 , Demo2 when they are void.
        // I can use array clone method in Demo1 to get the required result,
        // but it would be faster if Demo1 returned the result to main
    }
}

public class Demo1
{
    public static void Demo1(int A[])
    {
        int B[] = new int[A.length];
        System.out.println("B = "+Arrays.toString(B)); // output : B = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
        Demo2.Demo2(A,B);
        System.out.println("B = "+Arrays.toString(B)); // output : B = [9999, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
        System.out.println("A = "+Arrays.toString(A)); // output : A = [20, 19, 18, 4, 16, 15, 14, 4, 12, 11, 9]

        A = B;
        // A was pointing to location of Main_Array, now it points to location of B
        // Main_Array pointer still keeps pointing to the original location in void main

        System.out.println("A = "+Arrays.toString(A)); // output : A = [9999, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
        // Hence to access this result from main, I have to return it to main
    }
}
public class Demo2
{
    public static void Demo2(int AAA[],int BBB[])
    {
        BBB[0] = 9999;
        // BBB points to the same location as B in Demo1, so whatever I do
        // with BBB, I am manipulating the location. Since B points to the
        // same location, I can access the results from B
    }
}

How to open maximized window with Javascript?

If I use Firefox then screen.width and screen.height works fine but in IE and Chrome they don't work properly instead it opens with the minimum size.

And yes I tried giving too large numbers too like 10000 for both height and width but not exactly the maximized effect.

How do I export an Android Studio project?

Windows:

First Open Command Window and set location of your android studio project folder like:

D:\MyApplication>

then type below command in it:

gradlew clean

then wait for complete clean process. after complete it now zip your project like below:

  • right click on your project folder
  • then select send to option now
  • select compressed via zip

maven command line how to point to a specific settings.xml for a single command?

You can simply use:

mvn --settings YourOwnSettings.xml clean install

or

mvn -s YourOwnSettings.xml clean install

What is the simplest way to swap each pair of adjoining chars in a string with Python?

#Works on even/odd size strings
str = '2143657'
newStr = ''
for i in range(len(str)//2):
    newStr += str[i*2+1] + str[i*2]
if len(str)%2 != 0:
    newStr += str[-1]
print(newStr)

Warning comparison between pointer and integer

It should be

if (*message == '\0')

In C, simple quotes delimit a single character whereas double quotes are for strings.

How can I print the contents of an array horizontally?

Just loop through the array and write the items to the console using Write instead of WriteLine:

foreach(var item in array)
    Console.Write(item.ToString() + " ");

As long as your items don't have any line breaks, that will produce a single line.

...or, as Jon Skeet said, provide a little more context to your question.

Drop a temporary table if it exists

What you asked for is:

IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD') IS NOT NULL
    BEGIN
       DROP TABLE ##CLIENTS_KEYWORD

       CREATE TABLE ##CLIENTS_KEYWORD(client_id int)

    END
ELSE
   CREATE TABLE ##CLIENTS_KEYWORD(client_id int) 

IF OBJECT_ID('tempdb..##TEMP_CLIENTS_KEYWORD') IS NOT NULL
    BEGIN
       DROP TABLE ##TEMP_CLIENTS_KEYWORD

       CREATE TABLE ##TEMP_CLIENTS_KEYWORD(client_id int)

    END
ELSE
   CREATE TABLE ##TEMP_CLIENTS_KEYWORD(client_id int) 

Since you're always going to create the table, regardless of whether the table is deleted or not; a slightly optimised solution is:

IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD') IS NOT NULL
   DROP TABLE ##CLIENTS_KEYWORD

CREATE TABLE ##CLIENTS_KEYWORD(client_id int) 

IF OBJECT_ID('tempdb..##TEMP_CLIENTS_KEYWORD') IS NOT NULL
   DROP TABLE ##TEMP_CLIENTS_KEYWORD

CREATE TABLE ##TEMP_CLIENTS_KEYWORD(client_id int) 

PHP - print all properties of an object

<?php var_dump(obj) ?>

or

<?php print_r(obj) ?>

These are the same things you use for arrays too.

These will show protected and private properties of objects with PHP 5. Static class members will not be shown according to the manual.

If you want to know the member methods you can use get_class_methods():

$class_methods = get_class_methods('myclass');
// or
$class_methods = get_class_methods(new myclass());
foreach ($class_methods as $method_name) 
{
    echo "$method_name<br/>";
}

Related stuff:

get_object_vars()

get_class_vars()

get_class() <-- for the name of the instance

What does $1 [QSA,L] mean in my .htaccess file?

Not the place to give a complete tutorial, but here it is in short;

RewriteCond basically means "execute the next RewriteRule only if this is true". The !-l path is the condition that the request is not for a link (! means not, -l means link)

The RewriteRule basically means that if the request is done that matches ^(.+)$ (matches any URL except the server root), it will be rewritten as index.php?url=$1 which means a request for ollewill be rewritten as index.php?url=olle).

QSA means that if there's a query string passed with the original URL, it will be appended to the rewrite (olle?p=1 will be rewritten as index.php?url=olle&p=1.

L means if the rule matches, don't process any more RewriteRules below this one.

For more complete info on this, follow the links above. The rewrite support can be a bit hard to grasp, but there are quite a few examples on stackoverflow to learn from.

Make child visible outside an overflow:hidden parent

You can use the clearfix to do "layout preserving" the same way overflow: hidden does.

.clearfix:before,
.clearfix:after {
    content: ".";    
    display: block;    
    height: 0;    
    overflow: hidden; 
}
.clearfix:after { clear: both; }
.clearfix { zoom: 1; } /* IE < 8 */

add class="clearfix" class to the parent, and remove overflow: hidden;

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

Actually every object in javascript resolves to true if it has "a real value" as W3Cschools puts it. That means everything except "", NaN, undefined, null or 0.

Testing a number against a boolean with the == operator indeed is a tad weird, since the boolean gets converted into numerical 1 before comparing, which defies a little bit the logic behind the definition. This gets even more confusing when you do something like this:

_x000D_
_x000D_
    var fred = !!3; // will set fred to true _x000D_
    var joe = !!0; // will set joe to false_x000D_
    alert("fred = "+ fred + ", joe = "+ joe);
_x000D_
_x000D_
_x000D_

not everything in javascript makes a lot of sense ;)

Fixing slow initial load for IIS

See this article for tips on how to help performance issues. This includes both performance issues related to starting up, under the "cold start" section. Most of this will matter no matter what type of server you are using, locally or in production.

https://blogs.msdn.microsoft.com/b/mcsuksoldev/2011/01/19/common-performance-issues-on-asp-net-web-sites/

If the application deserializes anything from XML (and that includes web services…) make sure SGEN is run against all binaries involved in deseriaization and place the resulting DLLs in the Global Assembly Cache (GAC). This precompiles all the serialization objects used by the assemblies SGEN was run against and caches them in the resulting DLL. This can give huge time savings on the first deserialization (loading) of config files from disk and initial calls to web services. http://msdn.microsoft.com/en-us/library/bk3w6240(VS.80).aspx

If any IIS servers do not have outgoing access to the internet, turn off Certificate Revocation List (CRL) checking for Authenticode binaries by adding generatePublisherEvidence=”false” into machine.config. Otherwise every worker processes can hang for over 20 seconds during start-up while it times out trying to connect to the internet to obtain a CRL list. http://blogs.msdn.com/amolravande/archive/2008/07/20/startup-performance-disable-the-generatepublisherevidence-property.aspx

http://msdn.microsoft.com/en-us/library/bb629393.aspx

Consider using NGEN on all assemblies. However without careful use this doesn’t give much of a performance gain. This is because the base load addresses of all the binaries that are loaded by each process must be carefully set at build time to not overlap. If the binaries have to be rebased when they are loaded because of address clashes, almost all the performance gains of using NGEN will be lost. http://msdn.microsoft.com/en-us/magazine/cc163610.aspx

Spring data JPA query with parameter properties

This link will help you: Spring Data JPA M1 with SpEL expressions supported. The similar example would be:

@Query("select u from User u where u.firstname = :#{#customer.firstname}")
List<User> findUsersByCustomersFirstname(@Param("customer") Customer customer);

https://spring.io/blog/2014/07/15/spel-support-in-spring-data-jpa-query-definitions

Get bitcoin historical data

I have written a java example for this case:

Use json.org library to retrieve JSONObjects and JSONArrays. The example below uses blockchain.info's data which can be obtained as JSONObject.

    public class main 
    {
        public static void main(String[] args) throws MalformedURLException, IOException
        {
            JSONObject data = getJSONfromURL("https://blockchain.info/charts/market-price?format=json");
            JSONArray data_array = data.getJSONArray("values");

            for (int i = 0; i < data_array.length(); i++)
            {
                JSONObject price_point = data_array.getJSONObject(i);

                //  Unix time
                int x = price_point.getInt("x");

                //  Bitcoin price at that time
                double y = price_point.getDouble("y");

                //  Do something with x and y.
            }

        }

        public static JSONObject getJSONfromURL(String URL)
        {
            try
            {
                URLConnection uc;
                URL url = new URL(URL);
                uc = url.openConnection();
                uc.setConnectTimeout(10000);
                uc.addRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)");
                uc.connect();

                BufferedReader rd = new BufferedReader(
                        new InputStreamReader(uc.getInputStream(), 
                        Charset.forName("UTF-8")));

                StringBuilder sb = new StringBuilder();
                int cp;
                while ((cp = rd.read()) != -1)
                {
                    sb.append((char)cp);
                }

                String jsonText = (sb.toString());            

                return new JSONObject(jsonText.toString());
            } catch (IOException ex)
            {
                return null;
            }
        }
    }

How to take keyboard input in JavaScript?

Since event.keyCode is deprecated, I found the event.key useful in javascript. Below is an example for getting the names of the keyboard keys pressed (using an input element). They are given as a KeyboardEvent key text property:

_x000D_
_x000D_
function setMyKeyDownListener() {_x000D_
    window.addEventListener(_x000D_
      "keydown",_x000D_
      function(event) {MyFunction(event.key)}_x000D_
    )_x000D_
}_x000D_
_x000D_
function MyFunction (the_Key) {_x000D_
    alert("Key pressed is: "+the_Key);_x000D_
}
_x000D_
html { font-size: 4vw; background-color: green; color: white; padding: 1em; }
_x000D_
<body onload="setMyKeyDownListener()">_x000D_
    <div>_x000D_
        <input id="MyInputId">_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

If condition inside of map() React

You are using both ternary operator and if condition, use any one.

By ternary operator:

.map(id => {
    return this.props.schema.collectionName.length < 0 ?
        <Expandable>
            <ObjectDisplay
                key={id}
                parentDocumentId={id}
                schema={schema[this.props.schema.collectionName]}
                value={this.props.collection.documents[id]}
            />
        </Expandable>
    :
        <h1>hejsan</h1>
}

By if condition:

.map(id => {
    if(this.props.schema.collectionName.length < 0)
        return <Expandable>
                  <ObjectDisplay
                      key={id}
                      parentDocumentId={id}
                      schema={schema[this.props.schema.collectionName]}
                      value={this.props.collection.documents[id]}
                  />
              </Expandable>
    return <h1>hejsan</h1>
}

Read CSV file column by column

I sugges to use the Apache Commons CSV https://commons.apache.org/proper/commons-csv/

Here is one example:

    Path currentRelativePath = Paths.get("");
    String currentPath = currentRelativePath.toAbsolutePath().toString();
    String csvFile = currentPath + "/pathInYourProject/test.csv";

    Reader in;
    Iterable<CSVRecord> records = null;
    try
    {
        in = new FileReader(csvFile);
        records = CSVFormat.EXCEL.withHeader().parse(in); // header will be ignored
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }

    for (CSVRecord record : records) {
        String line = "";
        for ( int i=0; i < record.size(); i++)
        {
            if ( line == "" )
                line = line.concat(record.get(i));
            else
                line = line.concat("," + record.get(i));
        }
        System.out.println("read line: " + line);
    }

It automaticly recognize , and " but not ; (maybe it can be configured...).

My example file is:

col1,col2,col3
val1,"val2",val3
"val4",val5
val6;val7;"val8"

And output is:

read line: val1,val2,val3
read line: val4,val5
read line: val6;val7;"val8"

Last line is considered like one value.

How to add an auto-incrementing primary key to an existing table, in PostgreSQL?

To use an identity column in v10,

ALTER TABLE test 
ADD COLUMN id { int | bigint | smallint}
GENERATED { BY DEFAULT | ALWAYS } AS IDENTITY PRIMARY KEY;

For an explanation of identity columns, see https://blog.2ndquadrant.com/postgresql-10-identity-columns/.

For the difference between GENERATED BY DEFAULT and GENERATED ALWAYS, see https://www.cybertec-postgresql.com/en/sequences-gains-and-pitfalls/.

For altering the sequence, see https://popsql.io/learn-sql/postgresql/how-to-alter-sequence-in-postgresql/.

How can I change my Cygwin home folder after installation?

Change your HOME environment variable.

on XP, its right-click My Computer >> Properties >> Advanced >> Environment Variables >> User Variables for >> [select variable HOME] >> edit

How can I convert an image into a Base64 string?

If you need Base64 over JSON, check out Jackson: it has explicit support for binary data read/write as Base64 at both the low level (JsonParser, JsonGenerator) and data-binding level. So you can just have POJOs with byte[] properties, and encoding/decoding is automatically handled.

And pretty efficiently too, should that matter.

Programmatically Install Certificate into Mozilla

The easiest way is to import the certificate into a sample firefox-profile and then copy the cert8.db to the users you want equip with the certificate.

First import the certificate by hand into the firefox profile of the sample-user. Then copy

  • /home/${USER}/.mozilla/firefox/${randomalphanum}.default/cert8.db (Linux/Unix)

  • %userprofile%\Application Data\Mozilla\Firefox\Profiles\%randomalphanum%.default\cert8.db (Windows)

into the users firefox-profiles. That's it. If you want to make sure, that new users get the certificate automatically, copy cert8.db to:

  • /etc/firefox-3.0/profile (Linux/Unix)

  • %programfiles%\firefox-installation-folder\defaults\profile (Windows)

Checking if my Windows application is running

The recommended way is to use a Mutex. You can check out a sample here : http://www.codeproject.com/KB/cs/singleinstance.aspx

In specific the code:


        /// 
        /// check if given exe alread running or not
        /// 
        /// returns true if already running
        private static bool IsAlreadyRunning()
        {
            string strLoc = Assembly.GetExecutingAssembly().Location;
            FileSystemInfo fileInfo = new FileInfo(strLoc);
            string sExeName = fileInfo.Name;
            bool bCreatedNew;

            Mutex mutex = new Mutex(true, "Global\\"+sExeName, out bCreatedNew);
            if (bCreatedNew)
                mutex.ReleaseMutex();

            return !bCreatedNew;
        }

What is the advantage of using heredoc in PHP?

Some IDEs highlight the code in heredoc strings automatically - which makes using heredoc for XML or HTML visually appealing.

I personally like it for longer parts of i.e. XML since I don't have to care about quoting quote characters and can simply paste the XML.

Stack Memory vs Heap Memory

It's a language abstraction - some languages have both, some one, some neither.

In the case of C++, the code is not run in either the stack or the heap. You can test what happens if you run out of heap memory by repeatingly calling new to allocate memory in a loop without calling delete to free it it. But make a system backup before doing this.

How to write to error log file in PHP

you can simply use :

error_log("your message");

By default, the message will be send to the php system logger.

What’s the best way to reload / refresh an iframe?

Add empty space also reload the iFrame automatically.

document.getElementById('id').src += '';

Specifying an Index (Non-Unique Key) Using JPA

JPA 2.1 (finally) adds support for indexes and foreign keys! See this blog for details. JPA 2.1 is a part of Java EE 7, which is out .

If you like living on the edge, you can get the latest snapshot for eclipselink from their maven repository (groupId:org.eclipse.persistence, artifactId:eclipselink, version:2.5.0-SNAPSHOT). For just the JPA annotations (which should work with any provider once they support 2.1) use artifactID:javax.persistence, version:2.1.0-SNAPSHOT.

I'm using it for a project which won't be finished until after its release, and I haven't noticed any horrible problems (although I'm not doing anything too complex with it).

UPDATE (26 Sep 2013): Nowadays release and release candidate versions of eclipselink are available in the central (main) repository, so you no longer have to add the eclipselink repository in Maven projects. The latest release version is 2.5.0 but 2.5.1-RC3 is also present. I'd switch over to 2.5.1 ASAP because of issues with the 2.5.0 release (the modelgen stuff doesn't work).

Why can't I push to this bare repository?

git push --all

is the canonical way to push everything to a new bare repository.

Another way to do the same thing is to create your new, non-bare repository and then make a bare clone with

git clone --bare

then use

git remote add origin <new-remote-repo>

in the original (non-bare) repository.

Unable to set default python version to python3 in ubuntu

To change Python 3.6.8 as the default in Ubuntu 18.04 from Python 2.7 you can try the command line tool update-alternatives.

sudo update-alternatives --config python

If you get the error "no alternatives for python" then set up an alternative yourself with the following command:

sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 2

Change the path /usr/bin/python3 to your desired python version accordingly.

The last argument specified it priority means, if no manual alternative selection is made the alternative with the highest priority number will be set. In our case we have set a priority 2 for /usr/bin/python3.6.8 and as a result the /usr/bin/python3.6.8 was set as default python version automatically by update-alternatives command.

we can anytime switch between the above listed python alternative versions using below command and entering a selection number:

update-alternatives --config python

ASP MVC href to a controller/view

There are a couple of ways that you can accomplish this. You can do the following:

<li>
     @Html.ActionLink("Clients", "Index", "User", new { @class = "elements" }, null)
</li>

or this:

<li>
     <a href="@Url.Action("Index", "Users")" class="elements">
          <span>Clients</span>
     </a>
</li>

Lately I do the following:

<a href="@Url.Action("Index", null, new { area = string.Empty, controller = "User" }, Request.Url.Scheme)">
     <span>Clients</span>
</a>

The result would have http://localhost/10000 (or with whatever port you are using) to be appended to the URL structure like:

http://localhost:10000/Users

I hope this helps.

How to calculate cumulative normal distribution?

Taken from above:

from scipy.stats import norm
>>> norm.cdf(1.96)
0.9750021048517795
>>> norm.cdf(-1.96)
0.024997895148220435

For a two-tailed test:

Import numpy as np
z = 1.96
p_value = 2 * norm.cdf(-np.abs(z))
0.04999579029644087

How to use multiple databases in Laravel

Also you can use postgres fdw system

https://www.postgresql.org/docs/9.5/postgres-fdw.html

You will be able to connect different db in postgres. After that, in one query, you can access tables that are in different databases.

bash "if [ false ];" returns true instead of false -- why?

I found that I can do some basic logic by running something like:

A=true
B=true
if ($A && $B); then
    C=true
else
    C=false
fi
echo $C

How to append to a file in Node?

You need to open it, then write to it.

var fs = require('fs'), str = 'string to append to file';
fs.open('filepath', 'a', 666, function( e, id ) {
  fs.write( id, 'string to append to file', null, 'utf8', function(){
    fs.close(id, function(){
      console.log('file closed');
    });
  });
});

Here's a few links that will help explain the parameters

open
write
close


EDIT: This answer is no longer valid, look into the new fs.appendFile method for appending.

docker build with --build-arg with multiple arguments

The above answer by pl_rock is correct, the only thing I would add is to expect the ARG inside the Dockerfile if not you won't have access to it. So if you are doing

docker build -t essearch/ess-elasticsearch:1.7.6 --build-arg number_of_shards=5 --build-arg number_of_replicas=2 --no-cache .

Then inside the Dockerfile you should add

ARG number_of_replicas
ARG number_of_shards

I was running into this problem, so I hope I help someone (myself) in the future.

Hide text using css

See mezzoblue for a nice summary of each technique, with strengths and weaknesses, plus example html and css.

How do you specify a byte literal in Java?

If you're passing literals in code, what's stopping you from simply declaring it ahead of time?

byte b = 0; //Set to desired value.
f(b);

Exception Error c0000005 in VC++

I was having the same problem while running bulk tests for an assignment. Turns out when I relocated some iostream operations (printing to console) from class constructor to a method in class it was solved.

I assume it was something to do with iostream manipulations in the constructor.

Here is the fix:

// Before
CommandPrompt::CommandPrompt() : afs(nullptr), aff(nullptr) {
    cout << "Some text I was printing.." << endl;
};


// After
CommandPrompt::CommandPrompt() : afs(nullptr), aff(nullptr) {

};

Please feel free to explain more what the error is behind the scenes since it goes beyond my cpp knowledge.

how to set start value as "0" in chartjs?

If you need use it as a default configuration, just place min: 0 inside the node defaults.scale.ticks, as follows:

defaults: {
  global: {...},
  scale: {
    ...
    ticks: { min: 0 },
  }
},

Reference: https://www.chartjs.org/docs/latest/axes/

Differences between unique_ptr and shared_ptr

unique_ptr is the light-weight smart pointer of choice if you just have a dynamic object somewhere for which one consumer has sole (hence "unique") responsibility -- maybe a wrapper class that needs to maintain some dynamically allocated object. unique_ptr has very little overhead. It is not copyable, but movable. Its type is template <typename D, typename Deleter> class unique_ptr;, so it depends on two template parameters.

unique_ptr is also what auto_ptr wanted to be in the old C++ but couldn't because of that language's limitations.

shared_ptr on the other hand is a very different animal. The obvious difference is that you can have many consumers sharing responsibility for a dynamic object (hence "shared"), and the object will only be destroyed when all shared pointers have gone away. Additionally you can have observing weak pointers which will intelligently be informed if the shared pointer they're following has disappeared.

Internally, shared_ptr has a lot more going on: There is a reference count, which is updated atomically to allow the use in concurrent code. Also, there's plenty of allocation going on, one for an internal bookkeeping "reference control block", and another (often) for the actual member object.

But there's another big difference: The shared pointers type is always template <typename T> class shared_ptr;, and this is despite the fact that you can initialize it with custom deleters and with custom allocators. The deleter and allocator are tracked using type erasure and virtual function dispatch, which adds to the internal weight of the class, but has the enormous advantage that different sorts of shared pointers of type T are all compatible, no matter the deletion and allocation details. Thus they truly express the concept of "shared responsibility for T" without burdening the consumer with the details!

Both shared_ptr and unique_ptr are designed to be passed by value (with the obvious movability requirement for the unique pointer). Neither should make you worried about the overhead, since their power is truly astounding, but if you have a choice, prefer unique_ptr, and only use shared_ptr if you really need shared responsibility.

Android Studio: Unable to start the daemon process

Try deleting your .gradle from C:\Users\<username> directory and try again.

What GRANT USAGE ON SCHEMA exactly do?

For a production system, you can use this configuration :

--ACCESS DB
REVOKE CONNECT ON DATABASE nova FROM PUBLIC;
GRANT  CONNECT ON DATABASE nova  TO user;

--ACCESS SCHEMA
REVOKE ALL     ON SCHEMA public FROM PUBLIC;
GRANT  USAGE   ON SCHEMA public  TO user;

--ACCESS TABLES
REVOKE ALL ON ALL TABLES IN SCHEMA public FROM PUBLIC ;
GRANT SELECT                         ON ALL TABLES IN SCHEMA public TO read_only ;
GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA public TO read_write ;
GRANT ALL                            ON ALL TABLES IN SCHEMA public TO admin ;

Java 8 Distinct by property

The easiest way to implement this is to jump on the sort feature as it already provides an optional Comparator which can be created using an element’s property. Then you have to filter duplicates out which can be done using a statefull Predicate which uses the fact that for a sorted stream all equal elements are adjacent:

Comparator<Person> c=Comparator.comparing(Person::getName);
stream.sorted(c).filter(new Predicate<Person>() {
    Person previous;
    public boolean test(Person p) {
      if(previous!=null && c.compare(previous, p)==0)
        return false;
      previous=p;
      return true;
    }
})./* more stream operations here */;

Of course, a statefull Predicate is not thread-safe, however if that’s your need you can move this logic into a Collector and let the stream take care of the thread-safety when using your Collector. This depends on what you want to do with the stream of distinct elements which you didn’t tell us in your question.

How can I determine if an image has loaded, using Javascript/jQuery?

May I suggest a pure CSS solution altogether?

Just have a Div that you want to show the image in. Set the image as background. Then have the property background-size: cover or background-size: contain depending on how you want it.

cover will crop the image until smaller sides cover the box. contain will keep the entire image inside the div, leaving you with spaces on sides.

Check the snippet below.

_x000D_
_x000D_
div {_x000D_
  height: 300px;_x000D_
  width: 300px;_x000D_
  border: 3px dashed grey;_x000D_
  background-position: center;_x000D_
  background-repeat: no-repeat;_x000D_
}_x000D_
_x000D_
.cover-image {_x000D_
  background-size: cover;_x000D_
}_x000D_
_x000D_
.contain-image {_x000D_
  background-size: contain;_x000D_
}
_x000D_
<div class="cover-image" style="background-image:url(https://assets1.ignimgs.com/2019/04/25/avengers-endgame-1280y-1556226255823_1280w.jpg)">_x000D_
</div>_x000D_
<br/>_x000D_
<div class="contain-image" style="background-image:url(https://assets1.ignimgs.com/2019/04/25/avengers-endgame-1280y-1556226255823_1280w.jpg)">_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to create friendly URL in php?

According to this article, you want a mod_rewrite (placed in an .htaccess file) rule that looks something like this:

RewriteEngine on
RewriteRule ^/news/([0-9]+)\.html /news.php?news_id=$1

And this maps requests from

/news.php?news_id=63

to

/news/63.html

Another possibility is doing it with forcetype, which forces anything down a particular path to use php to eval the content. So, in your .htaccess file, put the following:

<Files news>
    ForceType application/x-httpd-php
</Files>

And then the index.php can take action based on the $_SERVER['PATH_INFO'] variable:

<?php
    echo $_SERVER['PATH_INFO'];
    // outputs '/63.html'
?>

Python's equivalent of && (logical-and) in an if-statement

You use and and or to perform logical operations like in C, C++. Like literally and is && and or is ||.


Take a look at this fun example,

Say you want to build Logic Gates in Python:

def AND(a,b):
    return (a and b) #using and operator

def OR(a,b):
    return (a or b)  #using or operator

Now try calling them:

print AND(False, False)
print OR(True, False)

This will output:

False
True

Hope this helps!

pass post data with window.location.href

Using window.location.href it's not possible to send a POST request.

What you have to do is to set up a form tag with data fields in it, set the action attribute of the form to the URL and the method attribute to POST, then call the submit method on the form tag.

How to find most common elements of a list?

The simple way of doing this would be (assuming your list is in 'l'):

>>> counter = {}
>>> for i in l: counter[i] = counter.get(i, 0) + 1
>>> sorted([ (freq,word) for word, freq in counter.items() ], reverse=True)[:3]
[(6, 'Jellicle'), (5, 'Cats'), (3, 'to')]

Complete sample:

>>> l = ['Jellicle', 'Cats', 'are', 'black', 'and', 'white,', 'Jellicle', 'Cats', 'are', 'rather', 'small;', 'Jellicle', 'Cats', 'are', 'merry', 'and', 'bright,', 'And', 'pleasant', 'to', 'hear', 'when', 'they', 'caterwaul.', 'Jellicle', 'Cats', 'have', 'cheerful', 'faces,', 'Jellicle', 'Cats', 'have', 'bright', 'black', 'eyes;', 'They', 'like', 'to', 'practise', 'their', 'airs', 'and', 'graces', 'And', 'wait', 'for', 'the', 'Jellicle', 'Moon', 'to', 'rise.', '']
>>> counter = {}
>>> for i in l: counter[i] = counter.get(i, 0) + 1
... 
>>> counter
{'and': 3, '': 1, 'merry': 1, 'rise.': 1, 'small;': 1, 'Moon': 1, 'cheerful': 1, 'bright': 1, 'Cats': 5, 'are': 3, 'have': 2, 'bright,': 1, 'for': 1, 'their': 1, 'rather': 1, 'when': 1, 'to': 3, 'airs': 1, 'black': 2, 'They': 1, 'practise': 1, 'caterwaul.': 1, 'pleasant': 1, 'hear': 1, 'they': 1, 'white,': 1, 'wait': 1, 'And': 2, 'like': 1, 'Jellicle': 6, 'eyes;': 1, 'the': 1, 'faces,': 1, 'graces': 1}
>>> sorted([ (freq,word) for word, freq in counter.items() ], reverse=True)[:3]
[(6, 'Jellicle'), (5, 'Cats'), (3, 'to')]

With simple I mean working in nearly every version of python.

if you don't understand some of the functions used in this sample, you can always do this in the interpreter (after pasting the code above):

>>> help(counter.get)
>>> help(sorted)

Counting the number of non-NaN elements in a numpy ndarray in Python

To determine if the array is sparse, it may help to get a proportion of nan values

np.isnan(ndarr).sum() / ndarr.size

If that proportion exceeds a threshold, then use a sparse array, e.g. - https://sparse.pydata.org/en/latest/

Differences between Lodash and Underscore.js

In 2014 I still think my point holds:

IMHO, this discussion got blown out of proportion quite a bit. Quoting the aforementioned blog post:

Most JavaScript utility libraries, such as Underscore, Valentine, and wu, rely on the “native-first dual approach.” This approach prefers native implementations, falling back to vanilla JavaScript only if the native equivalent is not supported. But jsPerf revealed an interesting trend: the most efficient way to iterate over an array or array-like collection is to avoid the native implementations entirely, opting for simple loops instead.

As if "simple loops" and "vanilla Javascript" are more native than Array or Object method implementations. Jeez ...

It certainly would be nice to have a single source of truth, but there isn't. Even if you've been told otherwise, there is no Vanilla God, my dear. I'm sorry. The only assumption that really holds is that we are all writing JavaScript code that aims at performing well in all major browsers, knowing that all of them have different implementations of the same things. It's a bitch to cope with, to put it mildly. But that's the premise, whether you like it or not.

Maybe all of you are working on large scale projects that need twitterish performance so that you really see the difference between 850,000 (Underscore.js) vs. 2,500,000 (Lodash) iterations over a list per second right now!

I for one am not. I mean, I worked on projects where I had to address performance issues, but they were never solved or caused by neither Underscore.js nor Lodash. And unless I get hold of the real differences in implementation and performance (we're talking C++ right now) of, let’s say, a loop over an iterable (object or array, sparse or not!), I rather don't get bothered with any claims based on the results of a benchmark platform that is already opinionated.

It only needs one single update of, let’s say, Rhino to set its Array method implementations on fire in a fashion that not a single "medieval loop methods perform better and forever and whatnot" priest can argue his/her way around the simple fact that all of a sudden array methods in Firefox are much faster than his/her opinionated brainfuck. Man, you just can't cheat your runtime environment by cheating your runtime environment! Think about that when promoting ...

your utility belt

... next time.

So to keep it relevant:

  • Use Underscore.js if you're into convenience without sacrificing native'ish.
  • Use Lodash if you're into convenience and like its extended feature catalogue (deep copy, etc.) and if you're in desperate need of instant performance and most importantly don't mind settling for an alternative as soon as native API's outshine opinionated workarounds. Which is going to happen soon. Period.
  • There's even a third solution. DIY! Know your environments. Know about inconsistencies. Read their (John-David's and Jeremy's) code. Don't use this or that without being able to explain why a consistency/compatibility layer is really needed and enhances your workflow or improves the performance of your application. It is very likely that your requirements are satisfied with a simple polyfill that you're perfectly able to write yourself. Both libraries are just plain vanilla with a little bit of sugar. They both just fight over who's serving the sweetest pie. But believe me, in the end both are only cooking with water. There's no Vanilla God so there can't be no Vanilla pope, right?

Choose whatever approach fits your needs the most. As usual. I'd prefer fallbacks on actual implementations over opinionated runtime cheats anytime, but even that seems to be a matter of taste nowadays. Stick to quality resources like http://developer.mozilla.com and http://caniuse.com and you'll be just fine.

Error when checking model input: expected convolution2d_input_1 to have 4 dimensions, but got array with shape (32, 32, 3)

You should simply apply the following transformation to your input data array.

input_data = input_data.reshape((-1, image_side1, image_side2, channels))

How do I determine height and scrolling position of window in jQuery?

$(window).height()

$(window).width()

There is also a plugin to jquery to determine element location and offsets

http://plugins.jquery.com/project/dimensions

scrolling offset = offsetHeight property of an element

Use PHP composer to clone git repo

In my case, I use Symfony2.3.x and the minimum-stability parameter is by default "stable" (which is good). I wanted to import a repo not in packagist but had the same issue "Your requirements could not be resolved to an installable set of packages.". It appeared that the composer.json in the repo I tried to import use a minimum-stability "dev".

So to resolve this issue, don't forget to verify the minimum-stability. I solved it by requiring a dev-master version instead of master as stated in this post.

How to represent matrices in python

((1,2,3,4),
 (5,6,7,8),
 (9,0,1,2))

Using tuples instead of lists makes it marginally harder to change the data structure in unwanted ways.

If you are going to do extensive use of those, you are best off wrapping a true number array in a class, so you can define methods and properties on them. (Or, you could NumPy, SciPy, ... if you are going to do your processing with those libraries.)

How to use Javascript to read local text file and read line by line?

Using ES6 the javascript becomes a little cleaner

handleFiles(input) {

    const file = input.target.files[0];
    const reader = new FileReader();

    reader.onload = (event) => {
        const file = event.target.result;
        const allLines = file.split(/\r\n|\n/);
        // Reading line by line
        allLines.forEach((line) => {
            console.log(line);
        });
    };

    reader.onerror = (event) => {
        alert(event.target.error.name);
    };

    reader.readAsText(file);
}

Rename file with Git

I had a similar problem going through a tutorial.

# git mv README README.markdown

fatal: bad source, source=README, destination=README.markdown

I included the filetype in the source file:

# git mv README.rdoc README.markdown

and it worked perfectly. Don't forget to commit the changes with i.e.:

# git commit -a -m "Improved the README"

Sometimes it is simple little things like that, that piss us off. LOL

Append a dictionary to a dictionary

dict.update() looks like it will do what you want...

>> orig.update(extra)
>>> orig
{'A': 1, 'C': 3, 'B': 2, 'E': 5, 'D': 4}
>>> 

Perhaps, though, you don't want to update your original dictionary, but work on a copy:

>>> dest = orig.copy()
>>> dest.update(extra)
>>> orig
{'A': 1, 'C': 3, 'B': 2}
>>> dest
{'A': 1, 'C': 3, 'B': 2, 'E': 5, 'D': 4}

Java JSON serialization - best practice

Have your tried json-io (https://github.com/jdereg/json-io)?

This library allows you to serialize / deserialize any Java object graph, including object graphs with cycles in them (e.g., A->B, B->A). It does not require your classes to implement any particular interface or inherit from any particular Java class.

In addition to serialization of Java to JSON (and JSON to Java), you can use it to format (pretty print) JSON:

String niceFormattedJson = JsonWriter.formatJson(jsonString)

Bootstrap push div content to new line

Do a row div.

Like this:

_x000D_
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.3/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-Zug+QiDoJOrZ5t4lssLdxGhVrurbmBWopoEl+M6BdEfwnCJZtKxi1KgxUyJq13dy" crossorigin="anonymous">_x000D_
<div class="grid">_x000D_
    <div class="row">_x000D_
        <div class="col-lg-3 col-md-3 col-sm-3 col-xs-12 bg-success">Under me should be a DIV</div>_x000D_
        <div class="col-lg-6 col-md-6 col-sm-5 col-xs-12 bg-danger">Under me should be a DIV</div>_x000D_
    </div>_x000D_
    <div class="row">_x000D_
        <div class="col-lg-3 col-md-3 col-sm-4 col-xs-12 bg-warning">I am the last DIV</div>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

CSS3 Transparency + Gradient

This is some really cool stuff! I needed pretty much the same, but with horizontal gradient from white to transparent. And it is working just fine! Here ist my code:

.gradient{
        /* webkit example */
        background-image: -webkit-gradient(
          linear, right top, left top, from(rgba(255, 255, 255, 1.0)),
          to(rgba(255, 255, 255, 0))
        );

        /* mozilla example - FF3.6+ */
        background-image: -moz-linear-gradient(
          right center,
          rgba(255, 255, 255, 1.0) 20%, rgba(255, 255, 255, 0) 95%
        );

        /* IE 5.5 - 7 */
        filter: progid:DXImageTransform.Microsoft.gradient(
          gradientType=1, startColor=0, endColorStr=#FFFFFF
        );

        /* IE8 uses -ms-filter for whatever reason... */
        -ms-filter: progid:DXImageTransform.Microsoft.gradient(
          gradientType=1, startColor=0, endColoStr=#FFFFFF
        );
    }

No assembly found containing an OwinStartupAttribute Error

Add class Startup.cs to root of project with next code:

using Microsoft.Owin;
using Owin;

[assembly: OwinStartupAttribute(typeof(ProjectName.Startup))]
namespace ProjectName
{
    public partial class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            ConfigureAuth(app);
        }
    }
}

Disable eslint rules for folder

The previous answers were in the right track, but the complete answer for this is going to Disabling rules only for a group of files, there you'll find the documentation needed to disable/enable rules for certain folders (Because in some cases you don't want to ignore the whole thing, only disable certain rules). Example:

{
    "env": {},
    "extends": [],
    "parser": "",
    "plugins": [],
    "rules": {},
    "overrides": [
      {
        "files": ["test/*.spec.js"], // Or *.test.js
        "rules": {
          "require-jsdoc": "off"
        }
      }
    ],
    "settings": {}
}

"’" showing on page instead of " ' "

You have a mismatch in your character encoding; your string is encoded in one encoding (UTF-8) and whatever is interpreting this page is using another (say ASCII).

Always specify your encoding in your http headers and make sure this matches your framework's definition of encoding.

Sample http header:

Content-Type    text/html; charset=utf-8

Setting encoding in asp.net

<configuration>
  <system.web>
    <globalization
      fileEncoding="utf-8"
      requestEncoding="utf-8"
      responseEncoding="utf-8"
      culture="en-US"
      uiCulture="de-DE"
    />
  </system.web>
</configuration>

Setting encoding in jsp

Use jQuery to change an HTML tag?

Rather than change the type of tag, you should be changing the style of the tag (or rather, the tag with a specific id.) Its not a good practice to be changing the elements of your document to apply stylistic changes. Try this:

$('a.change').click(function() {
    $('p#changed').css("font-weight", "bold");
});

<p id="changed">Hello!</p>
<a id="change">change</a>

How to insert data into elasticsearch

If you are using KIBANA with elasticsearch then you can use below RESt request to create and put in the index.

CREATING INDEX:

http://localhost:9200/company
PUT company
{
  "settings": {
    "index": {
      "number_of_shards": 1,
      "number_of_replicas": 1
    },
    "analysis": {
      "analyzer": {
        "analyzer-name": {
          "type": "custom",
          "tokenizer": "keyword",
          "filter": "lowercase"
        }
      }
    }
  },
  "mappings": {
    "employee": {
      "properties": {
        "age": {
          "type": "long"
        },
        "experience": {
          "type": "long"
        },
        "name": {
          "type": "text",
          "analyzer": "analyzer-name"
        }
      }
    }
  }
}

CREATING DOCUMENT:

POST http://localhost:9200/company/employee/2/_create
{
"name": "Hemani",
"age" : 23,
"experienceInYears" : 2
}

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.

Commenting multiple lines in DOS batch file

Just want to mention that pdub's GOTO solution is not fully correct in case :comment label appear in multiple times. I modify the code from this question as the example.

@ECHO OFF
SET FLAG=1
IF [%FLAG%]==[1] (
    ECHO IN THE FIRST IF...
    GOTO comment
    ECHO "COMMENT PART 1"
:comment
    ECHO HERE AT TD_NEXT IN THE FIRST BLOCK
)

IF [%FLAG%]==[1] (
    ECHO IN THE SECOND IF...
    GOTO comment
    ECHO "COMMENT PART"
:comment
    ECHO HERE AT TD_NEXT IN THE SECOND BLOCK
)

The output will be

IN THE FIRST IF...
HERE AT TD_NEXT IN THE SECOND BLOCK

The command ECHO HERE AT TD_NEXT IN THE FIRST BLOCK is skipped.

Fetching distinct values on a column using Spark DataFrame

Well to obtain all different values in a Dataframe you can use distinct. As you can see in the documentation that method returns another DataFrame. After that you can create a UDF in order to transform each record.

For example:

val df = sc.parallelize(Array((1, 2), (3, 4), (1, 6))).toDF("age", "salary")

// I obtain all different values. If you show you must see only {1, 3}
val distinctValuesDF = df.select(df("age")).distinct

// Define your udf. In this case I defined a simple function, but they can get complicated.
val myTransformationUDF = udf(value => value / 10)

// Run that transformation "over" your DataFrame
val afterTransformationDF = distinctValuesDF.select(myTransformationUDF(col("age")))

Java error - "invalid method declaration; return type required"

I had a similar issue when adding a class to the main method. Turns out it wasn't an issue, it was me not checking my spelling. So, as a noob, I learned that mis-spelling can and will mess things up. These posts helped me "see" my mistake and all is good now.

How do I make a file:// hyperlink that works in both IE and Firefox?

file Protocol
Opens a file on a local or network drive.

Syntax

Copy
 file:///sDrives[|sFile]
Tokens 

sDrives
Specifies the local or network drive.

sFile
Optional. Specifies the file to open. If sFile is omitted and the account accessing the drive has permission to browse the directory, a list of accessible files and directories is displayed.

Remarks

The file protocol and sDrives parameter can be omitted and substituted with just the command line representation of the drive letter and file location. For example, to browse the My Documents directory, the file protocol can be specified as file:///C|/My Documents/ or as C:\My Documents. In addition, a single '\' is equivalent to specifying the root directory on the primary local drive. On most computers, this is C:.

Available as of Microsoft Internet Explorer 3.0 or later.

Note Internet Explorer 6 Service Pack 1 (SP1) no longer allows browsing a local machine from the Internet zone. For instance, if an Internet site contains a link to a local file, Internet Explorer 6 SP1 displays a blank page when a user clicks on the link. Previous versions of Windows Internet Explorer followed the link to the local file.

Example

The following sample demonstrates four ways to use the File protocol.

Copy

//Specifying a drive and a file name. 

file:///C|/My Documents/ALetter.html

//Specifying only a drive and a path to browse the directory. 

file:///C|/My Documents/

//Specifying a drive and a directory using the command line representation of the directory location. 

C:\My Documents\

//Specifying only the directory on the local primary drive. 

\My Documents\

http://msdn.microsoft.com/en-us/library/aa767731

Why can I not push_back a unique_ptr into a vector?

You need to move the unique_ptr:

vec.push_back(std::move(ptr2x));

unique_ptr guarantees that a single unique_ptr container has ownership of the held pointer. This means that you can't make copies of a unique_ptr (because then two unique_ptrs would have ownership), so you can only move it.

Note, however, that your current use of unique_ptr is incorrect. You cannot use it to manage a pointer to a local variable. The lifetime of a local variable is managed automatically: local variables are destroyed when the block ends (e.g., when the function returns, in this case). You need to dynamically allocate the object:

std::unique_ptr<int> ptr(new int(1));

In C++14 we have an even better way to do so:

make_unique<int>(5);

ArrayList vs List<> in C#

Using List<T> you can prevent casting errors. It is very useful to avoid a runtime casting error.

Example:

Here (using ArrayList) you can compile this code but you will see an execution error later.

ArrayList array1 = new ArrayList();
array1.Add(1);
array1.Add("Pony"); //No error at compile process
int total = 0;
foreach (int num in array1)
{
 total += num; //-->Runtime Error
}

If you use List, you avoid these errors:

List<int> list1 = new List<int>();
list1.Add(1);
//list1.Add("Pony"); //<-- Error at compile process
int total = 0;
foreach (int num in list1 )
{
 total += num;
}

Reference: MSDN

Selenium: Can I set any of the attribute value of a WebElement in Selenium?

If you're using the PageFactory pattern or already have a reference to your WebElement, then you probably want to set the attribute, using your existing reference to the WebElement. (Rather than doing a document.getElementById(...) in your javascript)

The following sample allows you to set the attribute, using your existing WebElement reference.

Code Snippet

import org.openqa.selenium.WebElement;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.openqa.selenium.support.FindBy;

public class QuickTest {

    RemoteWebDriver driver;

    @FindBy(id = "foo")
    private WebElement username;

    public void exampleUsage(RemoteWebDriver driver) {
        setAttribute(username, "attr", "10");
        setAttribute(username, "value", "bar");
    }

    public void setAttribute(WebElement element, String attName, String attValue) {
        driver.executeScript("arguments[0].setAttribute(arguments[1], arguments[2]);", 
                element, attName, attValue);
    }
}

SQL Server: Difference between PARTITION BY and GROUP BY

Suppose we have 14 records of name column in table

in group by

select name,count(*) as totalcount from person where name='Please fill out' group BY name;

it will give count in single row i.e 14

but in partition by

select row_number() over (partition by name) as total from person where name = 'Please fill out';

it will 14 rows of increase in count

Web scraping with Python

You can use urllib2 to make the HTTP requests, and then you'll have web content.

You can get it like this:

import urllib2
response = urllib2.urlopen('http://example.com')
html = response.read()

Beautiful Soup is a python HTML parser that is supposed to be good for screen scraping.

In particular, here is their tutorial on parsing an HTML document.

Good luck!

Can't perform a React state update on an unmounted component

try changing setDivSizeThrottleable to

this.setDivSizeThrottleable = throttle(
  () => {
    if (this.isComponentMounted) {
      this.setState({
        pdfWidth: this.pdfWrapper!.getBoundingClientRect().width - 5,
      });
    }
  },
  500,
  { leading: false, trailing: true }
);

cURL POST command line on WINDOWS RESTful service

I ran into the same issue on my win7 x64 laptop and was able to get it working using the curl release that is labeled Win64 - Generic w SSL by using the very similar command line format:

C:\Projects\curl-7.23.1-win64-ssl-sspi>curl -H "Content-Type: application/json" -X POST http://localhost/someapi -d "{\"Name\":\"Test Value\"}"

Which only differs from your 2nd escape version by using double-quotes around the escaped ones and the header parameter value. Definitely prefer the linux shell syntax more.

What's the best way to detect a 'touch screen' device using JavaScript?

I think the best method is:

var isTouchDevice =
    (('ontouchstart' in window) ||
    (navigator.maxTouchPoints > 0) ||
    (navigator.msMaxTouchPoints > 0));
if(!isTouchDevice){
    /* Code for touch device /*
}else{
    /* Code for non touch device */
}

Update an outdated branch against master in a Git repo

Update the master branch, which you need to do regardless.

Then, one of:

  1. Rebase the old branch against the master branch. Solve the merge conflicts during rebase, and the result will be an up-to-date branch that merges cleanly against master.

  2. Merge your branch into master, and resolve the merge conflicts.

  3. Merge master into your branch, and resolve the merge conflicts. Then, merging from your branch into master should be clean.

None of these is better than the other, they just have different trade-off patterns.

I would use the rebase approach, which gives cleaner overall results to later readers, in my opinion, but that is nothing aside from personal taste.

To rebase and keep the branch you would:

git checkout <branch> && git rebase <target>

In your case, check out the old branch, then

git rebase master 

to get it rebuilt against master.

Checkbox Check Event Listener

If you have a checkbox in your html something like:

<input id="conducted" type = "checkbox" name="party" value="0">

and you want to add an EventListener to this checkbox using javascript, in your associated js file, you can do as follows:

checkbox = document.getElementById('conducted');

checkbox.addEventListener('change', e => {

    if(e.target.checked){
        //do something
    }

});

Send FormData and String Data Together Through JQuery AJAX?

var fd = new FormData();
var file_data = $('input[type="file"]')[0].files; // for multiple files
for(var i = 0;i<file_data.length;i++){
    fd.append("file_"+i, file_data[i]);
}
var other_data = $('form').serializeArray();
$.each(other_data,function(key,input){
    fd.append(input.name,input.value);
});
$.ajax({
    url: 'test.php',
    data: fd,
    contentType: false,
    processData: false,
    type: 'POST',
    success: function(data){
        console.log(data);
    }
});

Added a for loop and changed .serialize() to .serializeArray() for object reference in a .each() to append to the FormData.

How to configure socket connect timeout

I found this. Simpler than the accepted answer, and works with .NET v2

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

// Connect using a timeout (5 seconds)

IAsyncResult result = socket.BeginConnect( sIP, iPort, null, null );

bool success = result.AsyncWaitHandle.WaitOne( 5000, true );

if ( socket.Connected )
{
    socket.EndConnect( result );
}
else 
{
     // NOTE, MUST CLOSE THE SOCKET

     socket.Close();
     throw new ApplicationException("Failed to connect server.");
}

//... 

removing new line character from incoming stream using sed

To remove newlines, use tr:

tr -d '\n'

If you want to replace each newline with a single space:

tr '\n' ' '

The error ba: Event not found is coming from csh, and is due to csh trying to match !ba in your history list. You can escape the ! and write the command:

sed ':a;N;$\!ba;s/\n/ /g'  # Suitable for csh only!!

but sed is the wrong tool for this, and you would be better off using a shell that handles quoted strings more reasonably. That is, stop using csh and start using bash.

Overflow:hidden dots at the end

Yes, via the text-overflow property in CSS 3. Caveat: it is not universally supported yet in browsers.

How to get a view table query (code) in SQL Server 2008 Management Studio

right-click the view in the object-explorer, select "script view as...", then "create to" and then "new query editor window"

Escaping ampersand in URL

I would like to add a minor comment on Blender solution.

You can do the following:

var link = 'http://example.com?candy_name=' + encodeURIComponent('M&M');

That outputs:

http://example.com?candy_name=M%26M

The great thing about this it does not only work for & but for any especial character.

For instance:

var link = 'http://example.com?candy_name=' + encodeURIComponent('M&M?><')

Outputs:

"http://example.com?candy_name=M%26M%3F%3E%3C"

INSTALL_FAILED_USER_RESTRICTED : android studio using redmi 4 device

In your mobile device,make sure you have enabled the following buttons.

Settings > Additional Settings > Developer options

  1. Install via USB
  2. USB Debugging (Security settings)

enter image description here

ctypes - Beginner

The answer by Chinmay Kanchi is excellent but I wanted an example of a function which passes and returns a variables/arrays to a C++ code. I though I'd include it here in case it is useful to others.

Passing and returning an integer

The C++ code for a function which takes an integer and adds one to the returned value,

extern "C" int add_one(int i)
{
    return i+1;
}

Saved as file test.cpp, note the required extern "C" (this can be removed for C code). This is compiled using g++, with arguments similar to Chinmay Kanchi answer,

g++ -shared -o testlib.so -fPIC test.cpp

The Python code uses load_library from the numpy.ctypeslib assuming the path to the shared library in the same directory as the Python script,

import numpy.ctypeslib as ctl
import ctypes

libname = 'testlib.so'
libdir = './'
lib=ctl.load_library(libname, libdir)

py_add_one = lib.add_one
py_add_one.argtypes = [ctypes.c_int]
value = 5
results = py_add_one(value)
print(results)

This prints 6 as expected.

Passing and printing an array

You can also pass arrays as follows, for a C code to print the element of an array,

extern "C" void print_array(double* array, int N)
{
    for (int i=0; i<N; i++) 
        cout << i << " " << array[i] << endl;
}

which is compiled as before and the imported in the same way. The extra Python code to use this function would then be,

import numpy as np

py_print_array = lib.print_array
py_print_array.argtypes = [ctl.ndpointer(np.float64, 
                                         flags='aligned, c_contiguous'), 
                           ctypes.c_int]
A = np.array([1.4,2.6,3.0], dtype=np.float64)
py_print_array(A, 3)

where we specify the array, the first argument to print_array, as a pointer to a Numpy array of aligned, c_contiguous 64 bit floats and the second argument as an integer which tells the C code the number of elements in the Numpy array. This then printed by the C code as follows,

1.4
2.6
3.0

How to convert an OrderedDict into a regular dict in python3

Its simple way

>>import json 
>>from collection import OrderedDict

>>json.dumps(dict(OrderedDict([('method', 'constant'), ('data', '1.225')])))

How do you view ALL text from an ntext or nvarchar(max) in SSMS?

The easiest way to quickly view large varchar/text column:

declare @t varchar(max)

select @t = long_column from table

print @t

How to show the text on a ImageButton?

You can use a LinearLayout instead of using Button it's an arrangement i used in my app

 <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:background="@color/mainColor"
        android:orientation="horizontal"
        android:padding="10dp">

        <ImageView
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:background="@drawable/ic_cv"
            android:textColor="@color/offBack"
            android:textSize="20dp" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="@string/cartyCv"
            android:textColor="@color/offBack"
            android:textSize="25dp" />

    </LinearLayout>

How to delete zero components in a vector in Matlab?

You could use sparse(a), which would return

(1,2) 1

(1,4) 3

This allows you to keep the information about where your non-zero entries used to be.

How to check if string input is a number?

EDITED: You could also use this below code to find out if its a number or also a negative

import re
num_format = re.compile("^[\-]?[1-9][0-9]*\.?[0-9]+$")
isnumber = re.match(num_format,givennumber)
if isnumber:
    print "given string is number"

you could also change your format to your specific requirement. I am seeing this post a little too late.but hope this helps other persons who are looking for answers :) . let me know if anythings wrong in the given code.

.rar, .zip files MIME Type

For upload:

An official list of mime types can be found at The Internet Assigned Numbers Authority (IANA) . According to their list Content-Type header for zip is application/zip.

The media type for rar files is not officially registered at IANA but the unofficial commonly used mime-type value is application/x-rar-compressed.

application/octet-stream means as much as: "I send you a file stream and the content of this stream is not specified" (so it is true that it can be a zip or rar file as well). The server is supposed to detect what the actual content of the stream is.

Note: For upload it is not safe to rely on the mime type set in the Content-Type header. The header is set on the client and can be set to any random value. Instead you can use the php file info functions to detect the file mime-type on the server.


For download:

If you want to download a zip file and nothing else you should only set one single Accept header value. Any additional values set will be used as a fallback in case the server cannot satisfy your in the Accept header requested mime-type.

According to the WC3 specifications this:

application/zip, application/octet-stream 

will be intrepreted as: "I prefer a application/zip mime-type, but if you cannot deliver this an application/octet-stream (a file stream) is also fine".

So only a single:

application/zip

Will guarantee you a zip file (or a 406 - Not Acceptable response in case the server is unable to satisfy your request).

Server unable to read htaccess file, denying access to be safe

Important points in my experience:

  • every resource accessed by the server must be in an executable and readable directory, hence the xx5 in every chmod in other answers.
  • most of the time the webserver (apache in my case) is running neither as the user nor in the group that owns the directory, so again xx5 or chmod o+rx is necessary.

But the greater conclusion I reached is start from little to more.

For example, if http://myserver.com/sites/all/resources/assets/css/bootstrap.css yields a 403 error, see if http://myserver.com/ works, then sites, then sites/all, then sites/all/resources, and so on.

It will help if your server has directory indexes enable:

  • In Apache: Options +Indexes

This instruction might also be in the .htaccess of your webserver public_html folder.

JavaScript Array splice vs slice

_x000D_
_x000D_
//splice_x000D_
var array=[1,2,3,4,5];_x000D_
console.log(array.splice(2));_x000D_
_x000D_
//slice_x000D_
var array2=[1,2,3,4,5]_x000D_
console.log(array2.slice(2));_x000D_
_x000D_
_x000D_
console.log("----after-----");_x000D_
console.log(array);_x000D_
console.log(array2);
_x000D_
_x000D_
_x000D_

How do I get into a Docker container's shell?

I've created a terminal function for easier access to the container's terminal. Maybe it's useful to you guys as well:

So the result is, instead of typing:

docker exec -it [container_id] /bin/bash

you'll write:

dbash [container_id]

Put the following in your ~/.bash_profile (or whatever else that works for you), then open a new terminal window and enjoy the shortcut:

#usage: dbash [container_id]
dbash() {
    docker exec -it "$1" /bin/bash
}

Convert Char to String in C

FYI you dont have string datatype in C. Use array of characters to store the value and manipulate it. Change your variable c into an array of characters and use it inside a loop to get values.

char c[10];
int i=0;
while(i!=10)
{
    c[i]=fgetc(fp);
    i++;
}

The other way to do is to use pointers and allocate memory dynamically and assign values.

Two versions of python on linux. how to make 2.7 the default

You probably don't actually want to change your default Python.

Your distro installed a standard system Python in /usr/bin, and may have scripts that depend on this being present, and selected by #! /usr/bin/env python. You can usually get away with running Python 2.6 scripts in 2.7, but do you want to risk it?

On top of that, monkeying with /usr/bin can break your package manager's ability to manage packages. And changing the order of directories in your PATH will affect a lot of other things besides Python. (In fact, it's more common to have /usr/local/bin ahead of /usr/bin, and it may be what you actually want—but if you have it the other way around, presumably there's a good reason for that.)

But you don't need to change your default Python to get the system to run 2.7 when you type python.


First, you can set up a shell alias:

alias python=/usr/local/bin/python2.7

Type that at a prompt, or put it in your ~/.bashrc if you want the change to be persistent, and now when you type python it runs your chosen 2.7, but when some program on your system tries to run a script with /usr/bin/env python it runs the standard 2.6.


Alternatively, just create a virtual environment out of your 2.7 (or separate venvs for different projects), and do your work inside the venv.

tomcat - CATALINA_BASE and CATALINA_HOME variables

I can't say I know the best practice, but here's my perspective.

Are you using these variables for anything?

Personally, I haven't needed to change neither, on Linux nor Windows, in environments varying from development to production. Unless you are doing something particular that relies on them, chances are you could leave them alone.

catalina.sh sets the variables that Tomcat needs to work out of the box. It also says that CATALINA_BASE is optional:

#   CATALINA_HOME   May point at your Catalina "build" directory.
#
#   CATALINA_BASE   (Optional) Base directory for resolving dynamic portions
#                   of a Catalina installation.  If not present, resolves to
#                   the same directory that CATALINA_HOME points to.

I'm pretty sure you'll find out whether or not your setup works when you start your server.

Serializing to JSON in jQuery

If you don't want to use external libraries there is .toSource() native JavaScript method, but it's not perfectly cross-browser.