Programs & Examples On #Ajaxtags

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

That method was added in Servlet 2.5.

So this problem can have at least 3 causes:

  1. The servlet container does not support Servlet 2.5.
  2. The web.xml is not declared conform Servlet 2.5 or newer.
  3. The webapp's runtime classpath is littered with servlet container specific JAR files of a different servlet container make/version which does not support Servlet 2.5.

To solve it,

  1. Make sure that your servlet container supports at least Servlet 2.5. That are at least Tomcat 6, Glassfish 2, JBoss AS 4.1, etcetera. Tomcat 5.5 for example supports at highest Servlet 2.4. If you can't upgrade Tomcat, then you'd need to downgrade Spring to a Servlet 2.4 compatible version.
  2. Make sure that the root declaration of web.xml complies Servlet 2.5 (or newer, at least the highest whatever your target runtime supports). For an example, see also somewhere halfway our servlets wiki page.
  3. Make sure that you don't have any servlet container specific libraries like servlet-api.jar or j2ee.jar in /WEB-INF/lib or even worse, the JRE/lib or JRE/lib/ext. They do not belong there. This is a pretty common beginner's mistake in an attempt to circumvent compilation errors in an IDE, see also How do I import the javax.servlet API in my Eclipse project?.

Find files containing a given text

find . -type f -name '*php' -o -name '*js' -o -name '*html' |\
xargs grep -liE 'document\.cookie|setcookie'

How do I remove blank pages coming between two chapters in Appendix?

I tried Noah's suggestion which leads to the best solution up to now.

Just insert \let\cleardoublepage\clearpage before all the parts with the blank pages Especially when you use \documentclass[12pt,a4paper]{book}

frederic snyers's advice \documentclass[oneside]{book} is also very good and solves the problem, but if we just want to use the book.cls or article.cls, the one would make a big difference presenting your particles.

Hence, Big support to \let\cleardoublepage\clearpage for the people who will ask the same question in the future.

How create table only using <div> tag and Css

A bit OFF-TOPIC, but may help someone for a cleaner HTML... CSS

.common_table{
    display:table;
    border-collapse:collapse;
    border:1px solid grey;
    }
.common_table DIV{
    display:table-row;
    border:1px solid grey;
    }
.common_table DIV DIV{
    display:table-cell;
    }

HTML

<DIV class="common_table">
   <DIV><DIV>this is a cell</DIV></DIV>
   <DIV><DIV>this is a cell</DIV></DIV>
</DIV>

Works on Chrome and Firefox

Load RSA public key from file

Once you have your key stored in a PEM file, you can read it back easily using PemObject and PemReader classes provided by BouncyCastle, as shown in this this tutorial.

Create a PemFile class that encapsulates file handling:

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;

import org.bouncycastle.util.io.pem.PemObject;
import org.bouncycastle.util.io.pem.PemReader;

public class PemFile {

    private PemObject pemObject;

    public PemFile(String filename) throws FileNotFoundException, IOException {
        PemReader pemReader = new PemReader(new InputStreamReader(
                new FileInputStream(filename)));
        try {
            this.pemObject = pemReader.readPemObject();
        } finally {
            pemReader.close();
        }
    }

    public PemObject getPemObject() {
        return pemObject;
    }
}

Then instantiate private and public keys as usual:

import java.io.FileNotFoundException;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Security;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import org.apache.log4j.Logger;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

public class Main {

    protected final static Logger LOGGER = Logger.getLogger(Main.class);

    public final static String RESOURCES_DIR = "src/main/resources/rsa-sample/";

    public static void main(String[] args) throws FileNotFoundException,
            IOException, NoSuchAlgorithmException, NoSuchProviderException {
        Security.addProvider(new BouncyCastleProvider());
        LOGGER.info("BouncyCastle provider added.");

        KeyFactory factory = KeyFactory.getInstance("RSA", "BC");
        try {
            PrivateKey priv = generatePrivateKey(factory, RESOURCES_DIR
                    + "id_rsa");
            LOGGER.info(String.format("Instantiated private key: %s", priv));

            PublicKey pub = generatePublicKey(factory, RESOURCES_DIR
                    + "id_rsa.pub");
            LOGGER.info(String.format("Instantiated public key: %s", pub));
        } catch (InvalidKeySpecException e) {
            e.printStackTrace();
        }
    }

    private static PrivateKey generatePrivateKey(KeyFactory factory,
            String filename) throws InvalidKeySpecException,
            FileNotFoundException, IOException {
        PemFile pemFile = new PemFile(filename);
        byte[] content = pemFile.getPemObject().getContent();
        PKCS8EncodedKeySpec privKeySpec = new PKCS8EncodedKeySpec(content);
        return factory.generatePrivate(privKeySpec);
    }

    private static PublicKey generatePublicKey(KeyFactory factory,
            String filename) throws InvalidKeySpecException,
            FileNotFoundException, IOException {
        PemFile pemFile = new PemFile(filename);
        byte[] content = pemFile.getPemObject().getContent();
        X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(content);
        return factory.generatePublic(pubKeySpec);
    }
}

Hope this helps.

Node.js Mongoose.js string to ObjectId function

You can do it like this:

var mongoose = require('mongoose');
var _id = mongoose.mongo.BSONPure.ObjectID.fromHexString("4eb6e7e7e9b7f4194e000001");

EDIT: New standard has fromHexString rather than fromString

How to move screen without moving cursor in Vim?

Enter vim and type:

:help z

z is the vim command for redraw, so it will redraw the file relative to where you position the cursor. The options you have are as follows:

z+ - Redraws the file with the cursor at top of the window and at first non-blank character of your line.

z- - Redraws the file with the cursor at bottom of the window and at first non-blank character of your line.

z. - Redraws the file with the cursor at centre of the window and at first non-blank character of your line.

zt - Redraws file with the cursor at top of the window.

zb - Redraws file with the cursor at bottom of the window.

zz - Redraws file with the cursor at centre of the window.

"Expected BEGIN_OBJECT but was STRING at line 1 column 1"

I had a case where I read from a handwritten json file. The json is perfect. However, this error occurred. So I write from a java object to json file, then read from that json file. things are fine. I could not see any difference between the handwritten json and the one from java object. Tried beyondCompare it sees no difference. I finally noticed the two file sizes are slightly different, and I used winHex tool and detected extra stuff. So the solution for my situation is, make copy of the good json file, paste content into it and use.

enter image description here

How to redirect output of systemd service to a file

I think there's a more elegant way to solve the problem: send the stdout/stderr to syslog with an identifier and instruct your syslog manager to split its output by program name.

Use the following properties in your systemd service unit file:

StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=<your program identifier> # without any quote

Then, assuming your distribution is using rsyslog to manage syslogs, create a file in /etc/rsyslog.d/<new_file>.conf with the following content:

if $programname == '<your program identifier>' then /path/to/log/file.log
& stop

Now make the log file writable by syslog:

# ls -alth /var/log/syslog 
-rw-r----- 1 syslog adm 439K Mar  5 19:35 /var/log/syslog
# chown syslog:adm /path/to/log/file.log

Restart rsyslog (sudo systemctl restart rsyslog) and enjoy! Your program stdout/stderr will still be available through journalctl (sudo journalctl -u <your program identifier>) but they will also be available in your file of choice.

Source via archive.org

How to push object into an array using AngularJS

A couple of answers that should work above but this is how i would write it.

Also, i wouldn't declare controllers inside templates. It's better to declare them on your routes imo.

add-text.tpl.html

<div ng-controller="myController">
    <form ng-submit="addText(myText)">
        <input type="text" placeholder="Let's Go" ng-model="myText">
        <button type="submit">Add</button>
    </form>
    <ul>
        <li ng-repeat="text in arrayText">{{ text }}</li>
    </ul>
</div>

app.js

(function() {

    function myController($scope) {
        $scope.arrayText = ['hello', 'world'];
        $scope.addText = function(myText) {
             $scope.arrayText.push(myText);     
        };
    }

    angular.module('app', [])
        .controller('myController', myController);

})();

What is the best way to declare global variable in Vue.js?

I strongly recommend taking a look at Vuex, it is made for globally accessible data in Vue.

If you only need a few base variables that will never be modified, I would use ES6 imports:

// config.js
export default {
   hostname: 'myhostname'
}

// .vue file
import config from 'config.js'

console.log(config.hostname)

You could also import a json file in the same way, which can be edited by people without code knowledge or imported into SASS.

How to get index in Handlebars each helper?

I know this is too late. But i solved this issue with following Code:

Java Script:

Handlebars.registerHelper('eachData', function(context, options) {
      var fn = options.fn, inverse = options.inverse, ctx;
      var ret = "";

      if(context && context.length > 0) {
        for(var i=0, j=context.length; i<j; i++) {
          ctx = Object.create(context[i]);
          ctx.index = i;
          ret = ret + fn(ctx);
        }
      } else {
        ret = inverse(this);
      }
      return ret;
}); 

HTML:

{{#eachData items}}
 {{index}} // You got here start with 0 index
{{/eachData}}

if you want start your index with 1 you should do following code:

Javascript:

Handlebars.registerHelper('eachData', function(context, options) {
      var fn = options.fn, inverse = options.inverse, ctx;
      var ret = "";

      if(context && context.length > 0) {
        for(var i=0, j=context.length; i<j; i++) {
          ctx = Object.create(context[i]);
          ctx.index = i;
          ret = ret + fn(ctx);
        }
      } else {
        ret = inverse(this);
      }
      return ret;
    }); 

Handlebars.registerHelper("math", function(lvalue, operator, rvalue, options) {
    lvalue = parseFloat(lvalue);
    rvalue = parseFloat(rvalue);

    return {
        "+": lvalue + rvalue
    }[operator];
});

HTML:

{{#eachData items}}
     {{math index "+" 1}} // You got here start with 1 index
 {{/eachData}}

Thanks.

How do I encode URI parameter values?

Jersey's UriBuilder encodes URI components using application/x-www-form-urlencoded and RFC 3986 as needed. According to the Javadoc

Builder methods perform contextual encoding of characters not permitted in the corresponding URI component following the rules of the application/x-www-form-urlencoded media type for query parameters and RFC 3986 for all other components. Note that only characters not permitted in a particular component are subject to encoding so, e.g., a path supplied to one of the path methods may contain matrix parameters or multiple path segments since the separators are legal characters and will not be encoded. Percent encoded values are also recognized where allowed and will not be double encoded.

Converting HTML to PDF using PHP?

If you wish to create a pdf from php, pdflib will help you (as some others suggested).

Else, if you want to convert an HTML page to PDF via PHP, you'll find a little trouble outta here.. For 3 years I've been trying to do it as best as I can.

So, the options I know are:

DOMPDF : php class that wraps the html and builds the pdf. Works good, customizable (if you know php), based on pdflib, if I remember right it takes even some CSS. Bad news: slow when the html is big or complex.

HTML2PS: same as DOMPDF, but this one converts first to a .ps (ghostscript) file, then, to whatever format you need (pdf, jpg, png). For me is little better than dompdf, but has the same speed problem.. but, better compatibility with CSS.

Those two are php classes, but if you can install some software on the server, and access it throught passthru() or system(), give a look to these too:

wkhtmltopdf: based on webkit (safari's wrapper), is really fast and powerful.. seems like this is the best one (atm) for converting html pages to pdf on the fly; taking only 2 seconds for a 3 page xHTML document with CSS2. It is a recent project, anyway, the google.code page is often updated.

htmldoc : This one is a tank, it never really stops/crashes.. the project looks dead since 2007, but anyway if you don't need CSS compatibility this can be nice for you.

Loop through an array of strings in Bash?

Single line looping,

 declare -a listOfNames=('db_a' 'db_b' 'db_c')
 for databaseName in ${listOfNames[@]}; do echo $databaseName; done;

you will get an output like this,

db_a
db_b
db_c

WordPress is giving me 404 page not found for all pages except the homepage

Before trying to do any permalink or server config changes, please check you .htaccess file. This mostly is a corrupt or blank .htaccess file issue. Reset the htaccess file to the default

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

jquery <a> tag click event

All the hidden fields in your fieldset are using the same id, so jquery is only returning the first one. One way to fix this is to create a counter variable and concatenate it to each hidden field id.

Subtract two dates in Java

Assuming that you're constrained to using Date, you can do the following:

Date diff = new Date(d2.getTime() - d1.getTime());

Here you're computing the differences in milliseconds since the "epoch", and creating a new Date object at an offset from the epoch. Like others have said: the answers in the duplicate question are probably better alternatives (if you aren't tied down to Date).

What is the format specifier for unsigned short int?

Here is a good table for printf specifiers. So it should be %hu for unsigned short int.

And link to Wikipedia "C data types" too.

ListAGG in SQLSERVER

Starting in SQL Server 2017 the STRING_AGG function is available which simplifies the logic considerably:

select FieldA, string_agg(FieldB, '') as data
from yourtable
group by FieldA

See SQL Fiddle with Demo

In SQL Server you can use FOR XML PATH to get the result:

select distinct t1.FieldA,
  STUFF((SELECT distinct '' + t2.FieldB
         from yourtable t2
         where t1.FieldA = t2.FieldA
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,0,'') data
from yourtable t1;

See SQL Fiddle with Demo

How to send email via Django?

I found using SendGrid to be the easiest way to set up sending email with Django. Here's how it works:

  1. Create a SendGrid account (and verify your email)
  2. Add the following to your settings.py: EMAIL_HOST = 'smtp.sendgrid.net' EMAIL_HOST_USER = '<your sendgrid username>' EMAIL_HOST_PASSWORD = '<your sendgrid password>' EMAIL_PORT = 587 EMAIL_USE_TLS = True

And you're all set!

To send email:

from django.core.mail import send_mail
send_mail('<Your subject>', '<Your message>', '[email protected]', ['[email protected]'])

If you want Django to email you whenever there's a 500 internal server error, add the following to your settings.py:

DEFAULT_FROM_EMAIL = '[email protected]'
ADMINS = [('<Your name>', '[email protected]')]

Sending email with SendGrid is free up to 12k emails per month.

What is an Android PendingIntent?

A PendingIntent wraps the general Intent with a token that you give to foreign app to execute with your permission. For eg:

The notification of your music app can't play/pause the music if you didn't give the PendingIntent to send broadcast because your music app has READ_EXTERNAL_STORAGE permission which the notification app doesn't. Notification is a system service (so it's a foreign app).

Should switch statements always contain a default clause?

I believe this is quite language specific and for the C++ case a minor point for enum class type. Which appears more safe than traditional C enum. BUT

If you look at the implementation of std::byte its something like:

enum class byte : unsigned char {} ;

Source: https://en.cppreference.com/w/cpp/language/enum

And also consider this:

Otherwise, if T is a enumeration type that is either scoped or unscoped with fixed underlying type, and if the braced-init-list has only one initializer, and if the conversion from the initializer to the underlying type is non-narrowing, and if the initialization is direct-list-initialization, then the enumeration is initialized with the result of converting the initializer to its underlying type.

(since C++17)

Source: https://en.cppreference.com/w/cpp/language/list_initialization

This is an example of enum class representing values that are not defined enumerator. For this reason you cannot place complete trust in enums. Depending on application this might be important.

However, I really like what @Harlan Kassler said in his post and will start using that strategy in some situations myself.

Just an example of unsafe enum class:

enum class Numbers : unsigned
{
    One = 1u,
    Two = 2u
};

int main()
{
    Numbers zero{ 0u };
    return 0;
}

Posting a File and Associated Data to a RESTful WebService preferably as JSON

Since the only missing example is the ANDROID example, I'll add it. This technique uses a custom AsyncTask that should be declared inside your Activity class.

private class UploadFile extends AsyncTask<Void, Integer, String> {
    @Override
    protected void onPreExecute() {
        // set a status bar or show a dialog to the user here
        super.onPreExecute();
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        // progress[0] is the current status (e.g. 10%)
        // here you can update the user interface with the current status
    }

    @Override
    protected String doInBackground(Void... params) {
        return uploadFile();
    }

    private String uploadFile() {

        String responseString = null;
        HttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost("http://example.com/upload-file");

        try {
            AndroidMultiPartEntity ampEntity = new AndroidMultiPartEntity(
                new ProgressListener() {
                    @Override
                        public void transferred(long num) {
                            // this trigger the progressUpdate event
                            publishProgress((int) ((num / (float) totalSize) * 100));
                        }
            });

            File myFile = new File("/my/image/path/example.jpg");

            ampEntity.addPart("fileFieldName", new FileBody(myFile));

            totalSize = ampEntity.getContentLength();
            httpPost.setEntity(ampEntity);

            // Making server call
            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();

            int statusCode = httpResponse.getStatusLine().getStatusCode();
            if (statusCode == 200) {
                responseString = EntityUtils.toString(httpEntity);
            } else {
                responseString = "Error, http status: "
                        + statusCode;
            }

        } catch (Exception e) {
            responseString = e.getMessage();
        }
        return responseString;
    }

    @Override
    protected void onPostExecute(String result) {
        // if you want update the user interface with upload result
        super.onPostExecute(result);
    }

}

So, when you want to upload your file just call:

new UploadFile().execute();

date() method, "A non well formed numeric value encountered" does not want to format a date passed in $_POST

From the documentation for strtotime():

Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components: if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed.

In your date string, you have 12-16-2013. 16 isn't a valid month, and hence strtotime() returns false.

Since you can't use DateTime class, you could manually replace the - with / using str_replace() to convert the date string into a format that strtotime() understands:

$date = '2-16-2013';
echo date('Y-m-d', strtotime(str_replace('-','/', $date))); // => 2013-02-16

Removing whitespace from strings in Java

How about replaceAll("\\s", ""). Refer here.

Group by with multiple columns using lambda

     class Element
        {
            public string Company;        
            public string TypeOfInvestment;
            public decimal Worth;
        }

   class Program
    {
        static void Main(string[] args)
        {
         List<Element> elements = new List<Element>()
            {
                new Element { Company = "JPMORGAN CHASE",TypeOfInvestment = "Stocks", Worth = 96983 },
                new Element { Company = "AMER TOWER CORP",TypeOfInvestment = "Securities", Worth = 17141 },
                new Element { Company = "ORACLE CORP",TypeOfInvestment = "Assets", Worth = 59372 },
                new Element { Company = "PEPSICO INC",TypeOfInvestment = "Assets", Worth = 26516 },
                new Element { Company = "PROCTER & GAMBL",TypeOfInvestment = "Stocks", Worth = 387050 },
                new Element { Company = "QUASLCOMM INC",TypeOfInvestment = "Bonds", Worth = 196811 },
                new Element { Company = "UTD TECHS CORP",TypeOfInvestment = "Bonds", Worth = 257429 },
                new Element { Company = "WELLS FARGO-NEW",TypeOfInvestment = "Bank Account", Worth = 106600 },
                new Element { Company = "FEDEX CORP",TypeOfInvestment = "Stocks", Worth = 103955 },
                new Element { Company = "CVS CAREMARK CP",TypeOfInvestment = "Securities", Worth = 171048 },
            };

            //Group by on multiple column in LINQ (Query Method)
            var query = from e in elements
                        group e by new{e.TypeOfInvestment,e.Company} into eg
                        select new {eg.Key.TypeOfInvestment, eg.Key.Company, Points = eg.Sum(rl => rl.Worth)};



            foreach (var item in query)
            {
                Console.WriteLine(item.TypeOfInvestment.PadRight(20) + " " + item.Points.ToString());
            }


            //Group by on multiple column in LINQ (Lambda Method)
            var CompanyDetails =elements.GroupBy(s => new { s.Company, s.TypeOfInvestment})
                               .Select(g =>
                                            new
                                            {
                                                company = g.Key.Company,
                                                TypeOfInvestment = g.Key.TypeOfInvestment,            
                                                Balance = g.Sum(x => Math.Round(Convert.ToDecimal(x.Worth), 2)),
                                            }
                                      );
            foreach (var item in CompanyDetails)
            {
                Console.WriteLine(item.TypeOfInvestment.PadRight(20) + " " + item.Balance.ToString());
            }
            Console.ReadLine();

        }
    }

Violation Long running JavaScript task took xx ms

These are just warnings as everyone mentioned. However, if you're keen on resolving these (which you should), then you need to identify what is causing the warning first. There's no one reason due to which you can get force reflow warning. Someone has created a list for some possible options. You can follow the discussion for more information.
Here's the gist of the possible reasons:

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Element

Box metrics
  • elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
  • elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
  • elem.getClientRects(), elem.getBoundingClientRect()
Scroll stuff
  • elem.scrollBy(), elem.scrollTo()
  • elem.scrollIntoView(), elem.scrollIntoViewIfNeeded()
  • elem.scrollWidth, elem.scrollHeight
  • elem.scrollLeft, elem.scrollTop also, setting them
Focus
  • elem.focus() can trigger a double forced layout (source)
Also…
  • elem.computedRole, elem.computedName
  • elem.innerText (source)

getComputedStyle

window.getComputedStyle() will typically force style recalc (source)

window.getComputedStyle() will force layout, as well, if any of the following is true:

  1. The element is in a shadow tree
  2. There are media queries (viewport-related ones). Specifically, one of the following: (source) * min-width, min-height, max-width, max-height, width, height * aspect-ratio, min-aspect-ratio, max-aspect-ratio
    • device-pixel-ratio, resolution, orientation
  3. The property requested is one of the following: (source)
    • height, width * top, right, bottom, left * margin [-top, -right, -bottom, -left, or shorthand] only if the margin is fixed. * padding [-top, -right, -bottom, -left, or shorthand] only if the padding is fixed. * transform, transform-origin, perspective-origin * translate, rotate, scale * webkit-filter, backdrop-filter * motion-path, motion-offset, motion-rotation * x, y, rx, ry

window

  • window.scrollX, window.scrollY
  • window.innerHeight, window.innerWidth
  • window.getMatchedCSSRules() only forces style

Forms

  • inputElem.focus()
  • inputElem.select(), textareaElem.select() (source)

Mouse events

  • mouseEvt.layerX, mouseEvt.layerY, mouseEvt.offsetX, mouseEvt.offsetY (source)

document

  • doc.scrollingElement only forces style

Range

  • range.getClientRects(), range.getBoundingClientRect()

SVG

contenteditable

  • Lots & lots of stuff, …including copying an image to clipboard (source)

Check more here.

Also, here's Chromium source code from the original issue and a discussion about a performance API for the warnings.


Edit: There's also an article on how to minimize layout reflow on PageSpeed Insight by Google. It explains what browser reflow is:

Reflow is the name of the web browser process for re-calculating the positions and geometries of elements in the document, for the purpose of re-rendering part or all of the document. Because reflow is a user-blocking operation in the browser, it is useful for developers to understand how to improve reflow time and also to understand the effects of various document properties (DOM depth, CSS rule efficiency, different types of style changes) on reflow time. Sometimes reflowing a single element in the document may require reflowing its parent elements and also any elements which follow it.

In addition, it explains how to minimize it:

  1. Reduce unnecessary DOM depth. Changes at one level in the DOM tree can cause changes at every level of the tree - all the way up to the root, and all the way down into the children of the modified node. This leads to more time being spent performing reflow.
  2. Minimize CSS rules, and remove unused CSS rules.
  3. If you make complex rendering changes such as animations, do so out of the flow. Use position-absolute or position-fixed to accomplish this.
  4. Avoid unnecessary complex CSS selectors - descendant selectors in particular - which require more CPU power to do selector matching.

How to get Python requests to trust a self signed SSL certificate?

Setting export SSL_CERT_FILE=/path/file.crt should do the job.

Alternating Row Colors in Bootstrap 3 - No Table

You can use this code :

.row :nth-child(odd){
  background-color:red;
}
.row :nth-child(even){
  background-color:green;
}

Demo : http://codepen.io/mouhammed/pen/rblsC

Change auto increment starting number?

Procedure to auto fix AUTO_INCREMENT value of table

DROP PROCEDURE IF EXISTS update_auto_increment;
DELIMITER //
CREATE PROCEDURE update_auto_increment (_table VARCHAR(64))
BEGIN
    DECLARE _max_stmt VARCHAR(1024);
    DECLARE _stmt VARCHAR(1024);    
    SET @inc := 0;

    SET @MAX_SQL := CONCAT('SELECT IFNULL(MAX(`id`), 0) + 1 INTO @inc FROM ', _table);
    PREPARE _max_stmt FROM @MAX_SQL;
    EXECUTE _max_stmt;
    DEALLOCATE PREPARE _max_stmt;

    SET @SQL := CONCAT('ALTER TABLE ', _table, ' AUTO_INCREMENT =  ', @inc);
    PREPARE _stmt FROM @SQL;
    EXECUTE _stmt;
    DEALLOCATE PREPARE _stmt;
END//
DELIMITER ;

CALL update_auto_increment('your_table_name')

www-data permissions?

sudo chown -R yourname:www-data cake

then

sudo chmod -R g+s cake

First command changes owner and group.

Second command adds s attribute which will keep new files and directories within cake having the same group permissions.

Getting execute permission to xp_cmdshell

tchester said :

(2) Create a login for the non-sysadmin user that has public access to the master database

I went to my user's database list (server/security/connections/my user name/properties/user mapping, and wanted to check the box for master database. I got an error message telling that the user already exists in the master database. Went to master database, dropped the user, went back to "user mapping" and checked the box for master. Check the "public" box below.

After that, you need to re-issue the grant execute on xp_cmdshell to "my user name"

Yves

Difference between INNER JOIN and LEFT SEMI JOIN

Trying to depict with venn diagrams for better understanding..

Left Semi join : A semi join returns values from the left side of the relation that has a match with the right. It is also referred to as a left semi join.

enter image description here

Note : There is another thing called left anti join : An anti join returns values from the left relation that has no match with the right. It is also referred to as a left anti join.

Inner join : It selects rows that have matching values in both relations.

enter image description here

How to rollback or commit a transaction in SQL Server

The good news is a transaction in SQL Server can span multiple batches (each exec is treated as a separate batch.)

You can wrap your EXEC statements in a BEGIN TRANSACTION and COMMIT but you'll need to go a step further and rollback if any errors occur.

Ideally you'd want something like this:

BEGIN TRY
    BEGIN TRANSACTION 
        exec( @sqlHeader)
        exec(@sqlTotals)
        exec(@sqlLine)
    COMMIT
END TRY
BEGIN CATCH

    IF @@TRANCOUNT > 0
        ROLLBACK
END CATCH

The BEGIN TRANSACTION and COMMIT I believe you are already familiar with. The BEGIN TRY and BEGIN CATCH blocks are basically there to catch and handle any errors that occur. If any of your EXEC statements raise an error, the code execution will jump to the CATCH block.

Your existing SQL building code should be outside the transaction (above) as you always want to keep your transactions as short as possible.

adding onclick event to dynamically added button?

This code work good to me and look more simple. Necessary to call a function with specific parameter.

var btn = document.createElement("BUTTON");  //<button> element
var t = document.createTextNode("MyButton"); // Create a text node
btn.appendChild(t);   

btn.onclick = function(){myFunction(myparameter)};  
document.getElementById("myView").appendChild(btn);//to show on myView

How to query a CLOB column in Oracle

For big CLOB selects also can be used:

SELECT dbms_lob.substr( column_name, dbms_lob.getlength(column_name), 1) FROM foo

Get local IP address

Here is a modified version (from compman2408's one) which worked for me:

    internal static string GetLocalIPv4(NetworkInterfaceType _type)
    {  // Checks your IP adress from the local network connected to a gateway. This to avoid issues with double network cards
        string output = "";  // default output
        foreach (NetworkInterface item in NetworkInterface.GetAllNetworkInterfaces()) // Iterate over each network interface
        {  // Find the network interface which has been provided in the arguments, break the loop if found
            if (item.NetworkInterfaceType == _type && item.OperationalStatus == OperationalStatus.Up)
            {   // Fetch the properties of this adapter
                IPInterfaceProperties adapterProperties = item.GetIPProperties();
                // Check if the gateway adress exist, if not its most likley a virtual network or smth
                if (adapterProperties.GatewayAddresses.FirstOrDefault() != null)
                {   // Iterate over each available unicast adresses
                    foreach (UnicastIPAddressInformation ip in adapterProperties.UnicastAddresses)
                    {   // If the IP is a local IPv4 adress
                        if (ip.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                        {   // we got a match!
                            output = ip.Address.ToString();
                            break;  // break the loop!!
                        }
                    }
                }
            }
            // Check if we got a result if so break this method
            if (output != "") { break; }
        }
        // Return results
        return output;
    }

You can call this method for example like:

GetLocalIPv4(NetworkInterfaceType.Ethernet);

The change: I'm retrieving the IP from an adapter which has a gateway IP assigned to it. Second change: I've added docstrings and break statement to make this method more efficient.

How to force view controller orientation in iOS 8?

According to Korey Hinton's answer

Swift 2.2:

extension UINavigationController {
    public override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
        return visibleViewController!.supportedInterfaceOrientations()
    }
    public override func shouldAutorotate() -> Bool {
        return visibleViewController!.shouldAutorotate()
    }
}


extension UITabBarController {
    public override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
        if let selected = selectedViewController {
            return selected.supportedInterfaceOrientations()
        }
        return super.supportedInterfaceOrientations()
    }
    public override func shouldAutorotate() -> Bool {
        if let selected = selectedViewController {
            return selected.shouldAutorotate()
        }
        return super.shouldAutorotate()
    }
}

Disable Rotation

override func shouldAutorotate() -> Bool {
    return false
}

Lock to Specific Orientation

override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
    return UIInterfaceOrientationMask.Portrait
}

How to deep merge instead of shallow merge?

I know there's a lot of answers already and as many comments arguing they won't work. The only consensus is that it's so complicated that nobody made a standard for it. However, most of accepted answers in SO expose "simple tricks" that are widely used. So, for all of us like me who are no experts but want to write safer code by grasping a little more about javascript's complexity, I'll try to shed some light.

Before getting our hands dirty, let me clarify 2 points:

  • [DISCLAIMER] I propose a function below that tackles how we deep loop into javascript objects for copy and illustrates what is generally too shortly commented. It is not production-ready. For sake of clarity, I have purposedly left aside other considerations like circular objects (track by a set or unconflicting symbol property), copying reference value or deep clone, immutable destination object (deep clone again?), case-by-case study of each type of objects, get/set properties via accessors... Also, I did not test performance -although it's important- because it's not the point here either.
  • I'll use copy or assign terms instead of merge. Because in my mind a merge is conservative and should fail upon conflicts. Here, when conflicting, we want the source to overwrite the destination. Like Object.assign does.

Answers with for..in or Object.keys are misleading

Making a deep copy seems so basic and common practice that we expect to find a one-liner or, at least, a quick win via simple recursion. We don't expect we should need a library or write a custom function of 100 lines.

When I first read Salakar's answer, I genuinely thought I could do better and simpler (you can compare it with Object.assign on x={a:1}, y={a:{b:1}}). Then I read the8472's answer and I thought... there is no getting away so easily, improving already given answers won't get us far.

Let's let deep copy and recursive aside an instant. Just consider how (wrongly) people parse properties to copy a very simple object.

const y = Object.create(
    { proto : 1 },
    { a: { enumerable: true, value: 1},
      [Symbol('b')] : { enumerable: true, value: 1} } )

Object.assign({},y)
> { 'a': 1, Symbol(b): 1 } // All (enumerable) properties are copied

((x,y) => Object.keys(y).reduce((acc,k) => Object.assign(acc, { [k]: y[k] }), x))({},y)
> { 'a': 1 } // Missing a property!

((x,y) => {for (let k in y) x[k]=y[k];return x})({},y)
> { 'a': 1, 'proto': 1 } // Missing a property! Prototype's property is copied too!

Object.keys will omit own non-enumerable properties, own symbol-keyed properties and all prototype's properties. It may be fine if your objects don't have any of those. But keep it mind that Object.assign handles own symbol-keyed enumerable properties. So your custom copy lost its bloom.

for..in will provide properties of the source, of its prototype and of the full prototype chain without you wanting it (or knowing it). Your target may end up with too many properties, mixing up prototype properties and own properties.

If you're writing a general purpose function and you're not using Object.getOwnPropertyDescriptors, Object.getOwnPropertyNames, Object.getOwnPropertySymbols or Object.getPrototypeOf, you're most probably doing it wrong.

Things to consider before writing your function

First, make sure you understand what a Javascript object is. In Javascript, an object is made of its own properties and a (parent) prototype object. The prototype object in turn is made of its own properties and a prototype object. And so on, defining a prototype chain.

A property is a pair of key (string or symbol) and descriptor (value or get/set accessor, and attributes like enumerable).

Finally, there are many types of objects. You may want to handle differently an object Object from an object Date or an object Function.

So, writing your deep copy, you should answer at least those questions:

  1. What do I consider deep (proper for recursive look up) or flat?
  2. What properties do I want to copy? (enumerable/non-enumerable, string-keyed/symbol-keyed, own properties/prototype's own properties, values/descriptors...)

For my example, I consider that only the object Objects are deep, because other objects created by other constructors may not be proper for an in-depth look. Customized from this SO.

function toType(a) {
    // Get fine type (object, array, function, null, error, date ...)
    return ({}).toString.call(a).match(/([a-z]+)(:?\])/i)[1];
}

function isDeepObject(obj) {
    return "Object" === toType(obj);
}

And I made an options object to choose what to copy (for demo purpose).

const options = {nonEnum:true, symbols:true, descriptors: true, proto:true};

Proposed function

You can test it in this plunker.

function deepAssign(options) {
    return function deepAssignWithOptions (target, ...sources) {
        sources.forEach( (source) => {

            if (!isDeepObject(source) || !isDeepObject(target))
                return;

            // Copy source's own properties into target's own properties
            function copyProperty(property) {
                const descriptor = Object.getOwnPropertyDescriptor(source, property);
                //default: omit non-enumerable properties
                if (descriptor.enumerable || options.nonEnum) {
                    // Copy in-depth first
                    if (isDeepObject(source[property]) && isDeepObject(target[property]))
                        descriptor.value = deepAssign(options)(target[property], source[property]);
                    //default: omit descriptors
                    if (options.descriptors)
                        Object.defineProperty(target, property, descriptor); // shallow copy descriptor
                    else
                        target[property] = descriptor.value; // shallow copy value only
                }
            }

            // Copy string-keyed properties
            Object.getOwnPropertyNames(source).forEach(copyProperty);

            //default: omit symbol-keyed properties
            if (options.symbols)
                Object.getOwnPropertySymbols(source).forEach(copyProperty);

            //default: omit prototype's own properties
            if (options.proto)
                // Copy souce prototype's own properties into target prototype's own properties
                deepAssign(Object.assign({},options,{proto:false})) (// Prevent deeper copy of the prototype chain
                    Object.getPrototypeOf(target),
                    Object.getPrototypeOf(source)
                );

        });
        return target;
    }
}

That can be used like this:

const x = { a: { a: 1 } },
      y = { a: { b: 1 } };
deepAssign(options)(x,y); // { a: { a: 1, b: 1 } }

Multi column forms with fieldsets

There are a couple of things that need to be adjusted in your layout:

  1. You are nesting col elements within form-group elements. This should be the other way around (the form-group should be within the col-sm-xx element).

  2. You should always use a row div for each new "row" in your design. In your case, you would need at least 5 rows (Username, Password and co, Title/First/Last name, email, Language). Otherwise, your problematic .col-sm-12 is still on the same row with the above 3 .col-sm-4 resulting in a total of columns greater than 12, and causing the overlap problem.

Here is a fixed demo.

And an excerpt of what the problematic section HTML should become:

<fieldset>
    <legend>Personal Information</legend>
    <div class='row'>
        <div class='col-sm-4'>    
            <div class='form-group'>
                <label for="user_title">Title</label>
                <input class="form-control" id="user_title" name="user[title]" size="30" type="text" />
            </div>
        </div>
        <div class='col-sm-4'>
            <div class='form-group'>
                <label for="user_firstname">First name</label>
                <input class="form-control" id="user_firstname" name="user[firstname]" required="true" size="30" type="text" />
            </div>
        </div>
        <div class='col-sm-4'>
            <div class='form-group'>
                <label for="user_lastname">Last name</label>
                <input class="form-control" id="user_lastname" name="user[lastname]" required="true" size="30" type="text" />
            </div>
        </div>
    </div>
    <div class='row'>
        <div class='col-sm-12'>
            <div class='form-group'>

                <label for="user_email">Email</label>
                <input class="form-control required email" id="user_email" name="user[email]" required="true" size="30" type="text" />
            </div>
        </div>
    </div>
</fieldset>

Order Bars in ggplot2 bar graph

I think the already provided solutions are overly verbose. A more concise way to do a frequency sorted barplot with ggplot is

ggplot(theTable, aes(x=reorder(Position, -table(Position)[Position]))) + geom_bar()

It's similar to what Alex Brown suggested, but a bit shorter and works without an anynymous function definition.

Update

I think my old solution was good at the time, but nowadays I'd rather use forcats::fct_infreq which is sorting factor levels by frequency:

require(forcats)

ggplot(theTable, aes(fct_infreq(Position))) + geom_bar()

Notepad++ add to every line

Follow these steps:

  1. Press Ctrl+H to bring up the Find/Replace Dialog.
  2. Choose the Regular expression option near the bottom of the dialog.

To add a word, such as test, at the beginning of each line:

  1. Type ^ in the Find what textbox
  2. Type test in the Replace with textbox
  3. Place cursor in the first line of the file to ensure all lines are affected
  4. Click Replace All button

To add a word, such as test, at the end of each line:

  1. Type $ in the Find what textbox
  2. Type test in the Replace with textbox
  3. Place cursor in the first line of the file to ensure all lines are affected
  4. Click Replace All button

Setting the height of a DIV dynamically

document.getElementById('myDiv').style.height = 500;

This is the very basic JS code required to adjust the height of your object dynamically. I just did this very thing where I had some auto height property, but when I add some content via XMLHttpRequest I needed to resize my parent div and this offsetheight property did the trick in IE6/7 and FF3

How to pop an alert message box using PHP?

I have done it this way:

<?php 
$PHPtext = "Your PHP alert!";
?>

var JavaScriptAlert = <?php echo json_encode($PHPtext); ?>;
alert(JavaScriptAlert); // Your PHP alert!

PDO get the last ID inserted

That's because that's an SQL function, not PHP. You can use PDO::lastInsertId().

Like:

$stmt = $db->prepare("...");
$stmt->execute();
$id = $db->lastInsertId();

If you want to do it with SQL instead of the PDO API, you would do it like a normal select query:

$stmt = $db->query("SELECT LAST_INSERT_ID()");
$lastId = $stmt->fetchColumn();

Pushing to Git returning Error Code 403 fatal: HTTP request failed

Try to create your origin using SSH key instead of HTTP.

If you can initiate using SSH key then URL starts with:

[email protected]:<YOUR REPO URL>

Now you can add, commit & Push to your corresponding Branch

How to change the color of a SwitchCompat from AppCompat library

My working example of using style and android:theme simultaneously (API >= 21)

<android.support.v7.widget.SwitchCompat
    android:id="@+id/wan_enable_nat_switch"
    style="@style/Switch"
    app:layout_constraintBaseline_toBaselineOf="@id/wan_enable_nat_label"
    app:layout_constraintEnd_toEndOf="parent" />

<style name="Switch">
    <item name="android:layout_width">wrap_content</item>
    <item name="android:layout_height">wrap_content</item>
    <item name="android:paddingEnd">16dp</item>
    <item name="android:focusableInTouchMode">true</item>
    <item name="android:theme">@style/ThemeOverlay.MySwitchCompat</item>
</style>

<style name="ThemeOverlay.MySwitchCompat" parent="">
    <item name="colorControlActivated">@color/colorPrimaryDark</item>
    <item name="colorSwitchThumbNormal">@color/text_outline_not_active</item>
    <item name="android:colorForeground">#42221f1f</item>
</style>

Full examples of using pySerial package

I have not used pyserial but based on the API documentation at https://pyserial.readthedocs.io/en/latest/shortintro.html it seems like a very nice interface. It might be worth double-checking the specification for AT commands of the device/radio/whatever you are dealing with.

Specifically, some require some period of silence before and/or after the AT command for it to enter into command mode. I have encountered some which do not like reads of the response without some delay first.

How comment a JSP expression?

your <%= //map.size() %> doesnt simply work because it should have been

<% //= map.size() %>

GitHub: How to make a fork of public repository private?

The current answers are a bit out of date so, for clarity:

The short answer is:

  1. Do a bare clone of the public repo.
  2. Create a new private one.
  3. Do a mirror push to the new private one.

This is documented on GitHub: duplicating-a-repository

Concatenate two NumPy arrays vertically

A not well known feature of numpy is to use r_. This is a simple way to build up arrays quickly:

import numpy as np
a = np.array([1,2,3])
b = np.array([4,5,6])
c = np.r_[a[None,:],b[None,:]]
print(c)
#[[1 2 3]
# [4 5 6]]

The purpose of a[None,:] is to add an axis to array a.

Very simple C# CSV reader

Here's a simple function I made. It accepts a string CSV line and returns an array of fields:

It works well with Excel generated CSV files, and many other variations.

    public static string[] ParseCsvRow(string r)
    {

        string[] c;
        string t;
        List<string> resp = new List<string>();
        bool cont = false;
        string cs = "";

        c = r.Split(new char[] { ',' }, StringSplitOptions.None);

        foreach (string y in c)
        {
            string x = y;


            if (cont)
            {
                // End of field
                if (x.EndsWith("\""))
                {
                    cs += "," + x.Substring(0, x.Length - 1);
                    resp.Add(cs);
                    cs = "";
                    cont = false;
                    continue;

                }
                else
                {
                    // Field still not ended
                    cs += "," + x;
                    continue;
                }
            }

            // Fully encapsulated with no comma within
            if (x.StartsWith("\"") && x.EndsWith("\""))
            {
                if ((x.EndsWith("\"\"") && !x.EndsWith("\"\"\"")) && x != "\"\"")
                {
                    cont = true;
                    cs = x;
                    continue;
                }

                resp.Add(x.Substring(1, x.Length - 2));
                continue;
            }

            // Start of encapsulation but comma has split it into at least next field
            if (x.StartsWith("\"") && !x.EndsWith("\""))
            {
                cont = true;
                cs += x.Substring(1);
                continue;
            }

            // Non encapsulated complete field
            resp.Add(x);

        }

        return resp.ToArray();

    }

WAMP Server ERROR "Forbidden You don't have permission to access /phpmyadmin/ on this server."

I had done below changes for new phpmyadmin4.0.4 in httpd.conf file

<Directory />
    AllowOverride none
    Require all granted
</Directory>

and phpmyadmin.conf

<Directory "c:/wamp/apps/phpmyadmin4.0.4/">
    Options Indexes FollowSymLinks MultiViews
    AllowOverride all
        Order Allow,Deny
    Allow from all
</Directory>

and restart my server.

How to calculate cumulative normal distribution?

As Google gives this answer for the search netlogo pdf, here's the netlogo version of the above python code


    ;; Normal distribution cumulative density function
    to-report normcdf [x mu sigma]
        let t x - mu
        let y 0.5 * erfcc [ - t / ( sigma * sqrt 2.0)]
        if ( y > 1.0 ) [ set y 1.0 ]
        report y
    end

    ;; Normal distribution probability density function
    to-report normpdf [x mu sigma]
        let u = (x - mu) / abs sigma
        let y = 1 / ( sqrt [2 * pi] * abs sigma ) * exp ( - u * u / 2.0)
        report y
    end

    ;; Complementary error function
    to-report erfcc [x]
        let z abs x
        let t 1.0 / (1.0 + 0.5 * z)
        let r t *  exp ( - z * z -1.26551223 + t * (1.00002368 + t * (0.37409196 +
            t * (0.09678418 + t * (-0.18628806 + t * (.27886807 +
            t * (-1.13520398 +t * (1.48851587 +t * (-0.82215223 +
            t * .17087277 )))))))))
        ifelse (x >= 0) [ report r ] [report 2.0 - r]
    end

What is a "static" function in C?

static functions are functions that are only visible to other functions in the same file (more precisely the same translation unit).

EDIT: For those who thought, that the author of the questions meant a 'class method': As the question is tagged C he means a plain old C function. For (C++/Java/...) class methods, static means that this method can be called on the class itself, no instance of that class necessary.

Java Date - Insert into database

VALUES ('"+user+"' , '"+FirstTest+"'  , '"+LastTest+"'..............etc)

You can use it to insert variables into sql query.

Back button and refreshing previous activity

If not handling a callback from the editing activity (with onActivityResult), then I'd rather put the logic you mentioned in onStart (or possibly in onRestart), since having it in onResume just seems like overkill, given that changes are only occurring after onStop.

At any rate, be familiar with the Activity lifecycle. Plus, take note of the onRestoreInstanceState and onSaveInstanceState methods, which do not appear in the pretty lifecycle diagram.

(Also, it's worth reviewing how the Notepad Tutorial handles what you're doing, though it does use a database.)

404 Not Found The requested URL was not found on this server

change this

Include conf/extra/httpd-vhosts.conf

to

#Include conf/extra/httpd-vhosts.conf

and restart all services

Angular ForEach in Angular4/Typescript?

In Typescript use the For Each like below.

selectChildren(data, $event) {
let parentChecked = data.checked;
for(var obj in this.hierarchicalData)
    {
        for (var childObj in obj )
        {
            value.checked = parentChecked;
        }
    }
}

How to delete a row from GridView?

hi how to delete from datagridview

1.make query delete by id
2.type

tabletableadaptor.delete
query(datagridwiewX1.selectedrows[0].cell[0].value.tostring);

Basic Authentication Using JavaScript

EncodedParams variable is redefined as params variable will not work. You need to have same predefined call to variable, otherwise it looks possible with a little more work. Cheers! json is not used to its full capabilities in php there are better ways to call json which I don't recall at the moment.

Reading value from console, interactively

@rob answer will work most of the times, but it might not work as you expect with long inputs.

That is what you should be using instead:

const stdin = process.openStdin();
let content = '';

stdin.addListener('data', d => {
  content += d.toString();
});

stdin.addListener('end', () => {
  console.info(`Input: ${content}`);
});

Explanation on why this solution works:

addListener('data') works like a buffer, callback will be called when it is full or/and its the end of input.

What about long inputs? A single 'data' callback will not be enough, hence it you will get your input split in two or more parts. That is often not convenient.

addListener('end') will notify us when the stdin reader is done reading our input. Since we have been storing the previous data, we can now read and process it all together.

How to assign bean's property an Enum value in Spring config file?

Have you tried just "TYPE1"? I suppose Spring uses reflection to determine the type of "type" anyway, so the fully qualified name is redundant. Spring generally doesn't subscribe to redundancy!

How to Run a jQuery or JavaScript Before Page Start to Load

Don't use $(document).ready() just put the script directly in the head section of the page. Pages are processed top to bottom so things at the top are processed first.

Stored Procedure error ORA-06550

create or replace procedure point_triangle
AS
BEGIN
FOR thisteam in (select FIRSTNAME,LASTNAME,SUM(PTS)  from PLAYERREGULARSEASON  where TEAM    = 'IND' group by FIRSTNAME, LASTNAME order by SUM(PTS) DESC)

LOOP
dbms_output.put_line(thisteam.FIRSTNAME|| ' ' || thisteam.LASTNAME || ':' || thisteam.PTS);
END LOOP;

END;
/

AWS S3 - How to fix 'The request signature we calculated does not match the signature' error?

I got this error while trying to copy an object. I fixed it by encoding the copySource. This is actually described in the method documentation:

Params: copySource – The name of the source bucket and key name of the source object, separated by a slash (/). Must be URL-encoded.

CopyObjectRequest objectRequest = CopyObjectRequest.builder()
                .copySource(URLEncoder.encode(bucket + "/" + oldFileKey, "UTF-8"))
                .destinationBucket(bucket)
                .destinationKey(newFileKey)
                .build();

Equal height rows in a flex container

You can accomplish that now with display: grid:

_x000D_
_x000D_
.list {_x000D_
  display: grid;_x000D_
  overflow: hidden;_x000D_
  grid-template-columns: repeat(3, 1fr);_x000D_
  grid-auto-rows: 1fr;_x000D_
  grid-column-gap: 5px;_x000D_
  grid-row-gap: 5px;_x000D_
  max-width: 500px;_x000D_
}_x000D_
.list-item {_x000D_
  background-color: #ccc;_x000D_
  display: flex;_x000D_
  padding: 0.5em;_x000D_
  margin-bottom: 20px;_x000D_
}_x000D_
.list-content {_x000D_
  width: 100%;_x000D_
}
_x000D_
<ul class="list">_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
      <h2>box 1</h2>_x000D_
      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>_x000D_
    </div>_x000D_
  </li>_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
      <h3>box 2</h3>_x000D_
      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>_x000D_
    </div>_x000D_
  </li>_x000D_
_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
      <h3>box 2</h3>_x000D_
      <p>Lorem ipsum dolor</p>_x000D_
    </div>_x000D_
  </li>_x000D_
_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
      <h3>box 2</h3>_x000D_
      <p>Lorem ipsum dolor</p>_x000D_
    </div>_x000D_
  </li>_x000D_
  <li class="list-item">_x000D_
    <div class="list-content">_x000D_
      <h1>h1</h1>_x000D_
    </div>_x000D_
  </li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Although the grid itself is not flexbox, it behaves very similar to a flexbox container, and the items inside the grid can be flex.

The grid layout is also very handy in the case you want responsive grids. That is, if you want the grid to have a different number of columns per row you can then just change grid-template-columns:

grid-template-columns: repeat(1, 1fr); // 1 column
grid-template-columns: repeat(2, 1fr); // 2 columns
grid-template-columns: repeat(3, 1fr); // 3 columns

and so on...

You can mix it with media queries and change according to the size of the page.

Sadly there is still no support for container queries / element queries in the browsers (out of the box) to make it work well with changing the number of columns according to the container size, not to the page size (this would be great to use with reusable webcomponents).

More information about the grid layout:

https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Grid_Layout

Support of the Grid Layout accross browsers:

https://caniuse.com/#feat=css-grid

How do you return a JSON object from a Java Servlet

I do exactly what you suggest (return a String).

You might consider setting the MIME type to indicate you're returning JSON, though (according to this other stackoverflow post it's "application/json").

Entity Framework : How do you refresh the model when the db changes?

I've been working on a project, not too large, that incorporates Entity Framework, about a dozen tables, and about 15 stored procs and functions. After weeks of development, attempting to refresh my tables and stored procs has yielded mixed results as far as successfully updating the model. Sometimes the changes are effective, most times they are not. Simple column changes (changing order, adding, removing, or renaming) sometimes works, most times does not. Visual Studio seems to have more problems with refreshing than just adding new. It also exhibits more problems with stored proc changes not being reflected, especially when columns are added or deleted or renamed. I have not detected any consistent behavior so i can't say "This type of change will always be updated and this type of change will not".

End result, if you want 100% effective solution, delete the EDMX file from the project, "Add new" item to project (ADO.NET Entity Data Model), and make sure you use the same name for the Model Name. This works every time.

How to fix Git error: object file is empty?

  1. mv your folder app to make backup, i.e. mv app_folder app_folder_bk (it is like a git stash)
  2. git clone your_repository
  3. Finally,. Open a merge tool (I use meld diff viewer linux or Winmerge Windows) and copy the changes from right(app_folder_bk) to left( new app_folder) (it is like a git stash apply).

That's all. Maybe it is not the best way, but I think it is so practical .

Jquery function BEFORE form submission

You can do something like the following these days by referencing the "beforeSubmit" jquery form event. I'm disabling and enabling the submit button to avoid duplicate requests, submitting via ajax, returning a message that's a json array and displaying the information in a pNotify:

jQuery('body').on('beforeSubmit', "#formID", function() {
    $('.submitter').prop('disabled', true);
    var form = $('#formID');
    $.ajax({
        url    : form.attr('action'),
        type   : 'post',
        data   : form.serialize(),
        success: function (response)
        {
            response = jQuery.parseJSON(response);
            new PNotify({
                text: response.message,
                type: response.status,
                styling: 'bootstrap3',
                delay: 2000,
            });
            $('.submitter').prop('disabled', false);
        },
        error  : function ()
        {
            console.log('internal server error');
        }
    });
});

Why do I get the error "Unsafe code may only appear if compiling with /unsafe"?

Probably because you're using unsafe code.

Are you doing something with pointers or unmanaged assemblies somewhere?

Function for 'does matrix contain value X?'

Many ways to do this. ismember is the first that comes to mind, since it is a set membership action you wish to take. Thus

X = primes(20);
ismember([15 17],X)
ans =
      0    1

Since 15 is not prime, but 17 is, ismember has done its job well here.

Of course, find (or any) will also work. But these are not vectorized in the sense that ismember was. We can test to see if 15 is in the set represented by X, but to test both of those numbers will take a loop, or successive tests.

~isempty(find(X == 15))
~isempty(find(X == 17))

or,

any(X == 15)
any(X == 17)

Finally, I would point out that tests for exact values are dangerous if the numbers may be true floats. Tests against integer values as I have shown are easy. But tests against floating point numbers should usually employ a tolerance.

tol = 10*eps;
any(abs(X - 3.1415926535897932384) <= tol)

Getting SyntaxError for print with keyword argument end=' '

USE :: python3 filename.py

I had such error , this occured because i have two versions of python installed on my drive namely python2.7 and python3 . Following was my code :

#!usr/bin/python

f = open('lines.txt')
for line in f.readlines():
        print(line,end ='')

when i run it by the command python lines.py I got the following error

#!usr/bin/python

f = open('lines.txt')
for line in f.readlines():
        print(line,end ='')

when I run it by the command python3 lines.py I executed successfully

Undefined reference to sqrt (or other mathematical functions)

Here are my observation, firstly you need to include the header math.h as sqrt() function declared in math.h header file. For e.g

#include <math.h>

secondly, if you read manual page of sqrt you will notice this line Link with -lm.

#include <math.h> /* header file you need to include */

double sqrt(double x); /* prototype of sqrt() function */

Link with -lm. /* Library linking instruction */

But application still says undefined reference to sqrt. Do you see any problem here?

Compiler error is correct as you haven't linked your program with library lm & linker is unable to find reference of sqrt(), you need to link it explicitly. For e.g

gcc -Wall -Wextra -Werror -pedantic test.c -lm

Auto insert date and time in form input field?

<input id="date" name="date" />
<script type="text/javascript">
document.getElementById("date").value = new Date();
</script>

How do I use Maven through a proxy?

Some times you need to add other <proxy></proxy> tags, and specify the https in the protocol tags: <protocol>https</protocol>

convert string into array of integers

An alternative to Tushar Gupta answer would be :

'14 2'.split(' ').map(x=>+x);

// [14, 2]`

In code golf you save 1 character. Here the "+" is "unary plus" operator, works like parseInt.

NullInjectorError: No provider for AngularFirestore

I had the same issue while adding firebase to my Ionic App. To fix the issue I followed these steps:

npm install @angular/fire firebase --save

In my app/app.module.ts:

...
import { AngularFireModule } from '@angular/fire';
import { environment } from '../environments/environment';
import { AngularFirestoreModule, SETTINGS } from '@angular/fire/firestore';

@NgModule({
  declarations: [AppComponent],
  entryComponents: [],
  imports: [
    BrowserModule, 
    AppRoutingModule,
    AngularFireModule.initializeApp(environment.firebase),
    AngularFirestoreModule
  ],
  providers: [
    { provide: SETTINGS, useValue: {} }
  ],
  bootstrap: [AppComponent]
})

Previously we used FirestoreSettingsToken instead of SETTINGS. But that bug got resolved, now we use SETTINGS. (link)

In my app/services/myService.ts I imported as:

import { AngularFirestore } from "@angular/fire/firestore";

For some reason vscode was importing it as "@angular/fire/firestore/firestore";I After changing it for "@angular/fire/firestore"; the issue got resolved!

How to make Toolbar transparent?

Add the following line in style.xml

<style name="Base.Theme.AppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

<style name="AppTheme" parent="Base.Theme.AppTheme">
</style>

Now add the following line in style-v21,

  <style name="AppTheme" parent="Base.Theme.AppTheme">
    <item name="android:windowDrawsSystemBarBackgrounds">true</item>
    <item name="android:statusBarColor">@android:color/transparent</item>
</style>

and set the theme as android:theme="@style/AppTheme"

It will make the status bar transparent.

Determine if an element has a CSS class with jQuery

from the FAQ

elem = $("#elemid");
if (elem.is (".class")) {
   // whatever
}

or:

elem = $("#elemid");
if (elem.hasClass ("class")) {
   // whatever
}

DropDownList's SelectedIndexChanged event not firing

Also make sure the page is valid. You can check this in the browsers developer tools (F12)

In the Console tab select the correct Target/Frame and check for the [Page_IsValid] property

If the page is not valid the form will not submit and therefore not fire the event.

Checking if jquery is loaded using Javascript

A quick way is to run a jQuery command in the developer console. On any browser hit F12 and try to access any of the element .

 $("#sideTab2").css("background-color", "yellow");

enter image description here

check if a number already exist in a list in python

If you want your numbers in ascending order you can add them into a set and then sort the set into an ascending list.

s = set()
if number1 not in s:
  s.add(number1)
if number2 not in s:
  s.add(number2)
...
s = sorted(s)  #Now a list in ascending order

sklearn: Found arrays with inconsistent numbers of samples when calling LinearRegression.fit()

Seen on the Udacity deep learning foundation course:

df = pd.read_csv('my.csv')
...
regr = LinearRegression()
regr.fit(df[['column x']], df[['column y']])

How to start working with GTest and CMake

Yours and VladLosevs' solutions are probably better than mine. If you want a brute-force solution, however, try this:

SET(CMAKE_EXE_LINKER_FLAGS /NODEFAULTLIB:\"msvcprtd.lib;MSVCRTD.lib\")

FOREACH(flag_var
    CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
    CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
    if(${flag_var} MATCHES "/MD")
        string(REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
    endif(${flag_var} MATCHES "/MD")
ENDFOREACH(flag_var)

Golang read request body

Inspecting and mocking request body

When you first read the body, you have to store it so once you're done with it, you can set a new io.ReadCloser as the request body constructed from the original data. So when you advance in the chain, the next handler can read the same body.

One option is to read the whole body using ioutil.ReadAll(), which gives you the body as a byte slice.

You may use bytes.NewBuffer() to obtain an io.Reader from a byte slice.

The last missing piece is to make the io.Reader an io.ReadCloser, because bytes.Buffer does not have a Close() method. For this you may use ioutil.NopCloser() which wraps an io.Reader, and returns an io.ReadCloser, whose added Close() method will be a no-op (does nothing).

Note that you may even modify the contents of the byte slice you use to create the "new" body. You have full control over it.

Care must be taken though, as there might be other HTTP fields like content-length and checksums which may become invalid if you modify only the data. If subsequent handlers check those, you would also need to modify those too!

Inspecting / modifying response body

If you also want to read the response body, then you have to wrap the http.ResponseWriter you get, and pass the wrapper on the chain. This wrapper may cache the data sent out, which you can inspect either after, on on-the-fly (as the subsequent handlers write to it).

Here's a simple ResponseWriter wrapper, which just caches the data, so it'll be available after the subsequent handler returns:

type MyResponseWriter struct {
    http.ResponseWriter
    buf *bytes.Buffer
}

func (mrw *MyResponseWriter) Write(p []byte) (int, error) {
    return mrw.buf.Write(p)
}

Note that MyResponseWriter.Write() just writes the data to a buffer. You may also choose to inspect it on-the-fly (in the Write() method) and write the data immediately to the wrapped / embedded ResponseWriter. You may even modify the data. You have full control.

Care must be taken again though, as the subsequent handlers may also send HTTP response headers related to the response data –such as length or checksums– which may also become invalid if you alter the response data.

Full example

Putting the pieces together, here's a full working example:

func loginmw(handler http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        body, err := ioutil.ReadAll(r.Body)
        if err != nil {
            log.Printf("Error reading body: %v", err)
            http.Error(w, "can't read body", http.StatusBadRequest)
            return
        }

        // Work / inspect body. You may even modify it!

        // And now set a new body, which will simulate the same data we read:
        r.Body = ioutil.NopCloser(bytes.NewBuffer(body))

        // Create a response wrapper:
        mrw := &MyResponseWriter{
            ResponseWriter: w,
            buf:            &bytes.Buffer{},
        }

        // Call next handler, passing the response wrapper:
        handler.ServeHTTP(mrw, r)

        // Now inspect response, and finally send it out:
        // (You can also modify it before sending it out!)
        if _, err := io.Copy(w, mrw.buf); err != nil {
            log.Printf("Failed to send out response: %v", err)
        }
    })
}

How to make a input field readonly with JavaScript?

document.getElementById('TextBoxID').readOnly = true;    //to enable readonly


document.getElementById('TextBoxID').readOnly = false;   //to  disable readonly

How to create JSON post to api using C#

Try using Web API HttpClient

    static async Task RunAsync()
    {
        using (var client = new HttpClient())
        {
            client.BaseAddress = new Uri("http://domain.com/");
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));


            // HTTP POST
            var obj = new MyObject() { Str = "MyString"};
            response = await client.PostAsJsonAsync("POST URL GOES HERE?", obj );
            if (response.IsSuccessStatusCode)
            {
                response.//.. Contains the returned content.
            }
        }
    }

You can find more details here Web API Clients

Android - How to decode and decompile any APK file?

To decompile APK Use APKTool.
You can learn how APKTool works on http://www.decompileandroid.com/ or by reading the documentation.

How can I enable CORS on Django REST Framework

For Django versions > 1.10, according to the documentation, a custom MIDDLEWARE can be written as a function, let's say in the file: yourproject/middleware.py (as a sibling of settings.py):

def open_access_middleware(get_response):
    def middleware(request):
        response = get_response(request)
        response["Access-Control-Allow-Origin"] = "*"
        response["Access-Control-Allow-Headers"] = "*"
        return response
    return middleware

and finally, add the python path of this function (w.r.t. the root of your project) to the MIDDLEWARE list in your project's settings.py:

MIDDLEWARE = [
  .
  .
  'django.middleware.clickjacking.XFrameOptionsMiddleware',
  'yourproject.middleware.open_access_middleware'
]

Easy peasy!

How to export data with Oracle SQL Developer?

If, at some point, you only need to export a single result set, just right click "on the data" (any column of any row) there you will find an export option. The wizard exports the complete result set regardless of what you selected

php: check if an array has duplicates

You can do:

function has_dupes($array) {
    $dupe_array = array();
    foreach ($array as $val) {
        if (++$dupe_array[$val] > 1) {
            return true;
        }
    }
    return false;
}

Folder structure for a Node.js project

There is a discussion on GitHub because of a question similar to this one: https://gist.github.com/1398757

You can use other projects for guidance, search in GitHub for:

  • ThreeNodes.js - in my opinion, seems to have a specific structure not suitable for every project;
  • lighter - an more simple structure, but lacks a bit of organization;

And finally, in a book (http://shop.oreilly.com/product/0636920025344.do) suggests this structure:

+-- index.html
+-- js/
¦   +-- main.js
¦   +-- models/
¦   +-- views/
¦   +-- collections/
¦   +-- templates/
¦   +-- libs/
¦       +-- backbone/
¦       +-- underscore/
¦       +-- ...
+-- css/
+-- ...

SQLite add Primary Key

You can't modify SQLite tables in any significant way after they have been created. The accepted suggested solution is to create a new table with the correct requirements and copy your data into it, then drop the old table.

here is the official documentation about this: http://sqlite.org/faq.html#q11

How to select rows with no matching entry in another table?

Where T2 is the table to which you're adding the constraint:

SELECT *
FROM T2
WHERE constrained_field NOT
IN (
    SELECT DISTINCT t.constrained_field
    FROM T2 
    INNER JOIN T1 t
    USING ( constrained_field )
)

And delete the results.

How to get the first word in the string

Don't need a regex. string[: string.find(' ')]

Completely cancel a rebase

You are lucky that you didn't complete the rebase, so you can still do git rebase --abort. If you had completed the rebase (it rewrites history), things would have been much more complex. Consider tagging the tips of branches before doing potentially damaging operations (particularly history rewriting), that way you can rewind if something blows up.

Getting a HeadlessException: No X11 DISPLAY variable was set

This appears to be a more general SWING/AWT/JDK problem that just the JBOSS installer:

The accepted answer below solved the issue for me :

Unable to run java gui programs with ubuntu

("sudo apt-get install openjdk-6-jdk")

Difference between "process.stdout.write" and "console.log" in node.js?

I've just noticed something while researching this after getting help with https.request for post method. Thought I share some input to help understand.

process.stdout.write doesn't add a new line while console.log does, like others had mentioned. But there's also this which is easier to explain with examples.

var req = https.request(options, (res) => {
    res.on('data', (d) => {
        process.stdout.write(d);
        console.log(d)
    });
});

process.stdout.write(d); will print the data properly without a new line. However console.log(d) will print a new line but the data won't show correctly, giving this <Buffer 12 34 56... for example.

To make console.log(d) show the information correctly, I would have to do this.

var req = https.request(options, (res) => {
    var dataQueue = "";    
    res.on("data", function (d) {
        dataQueue += d;
    });
    res.on("end", function () {
        console.log(dataQueue);
    });
});

So basically:

  • process.stdout.write continuously prints the information as the data being retrieved and doesn't add a new line.

  • console.log prints the information what was obtained at the point of retrieval and adds a new line.

That's the best way I can explain it.

PHP to write Tab Characters inside a file?

Use \t and enclose the string with double-quotes:

$chunk = "abc\tdef\tghi";

How can I list all collections in the MongoDB shell?

On >=2.x, you can do

db.listCollections()

On 1.x you can do

db.getCollectionNames()

Things possible in IntelliJ that aren't possible in Eclipse?

I don't remember if word/line/method/class wrap is possible in Eclipse

In Intellij Idea you use Ctrl+W

event.preventDefault() vs. return false

Prevent Default

Calling preventDefault() during any stage of event flow cancels the event, meaning that any default action normally taken by the implementation as a result of the event will not occur. You can use Event.

return false

return false inside a callback prevents the default behaviour. For example, in a submit event, it doesn't submit the form. return false also stops bubbling, so the parents of the element won't know the event occurred. return false is equivalent to event.preventDefault() + event.stopPropagation()

Xcopy Command excluding files and folders

Like Andrew said /exclude parameter of xcopy should be existing file that has list of excludes.

Documentation of xcopy says:

Using /exclude

List each string in a separate line in each file. If any of the listed strings match any part of the absolute path of the file to be copied, that file is then excluded from the copying process. For example, if you specify the string "\Obj\", you exclude all files underneath the Obj directory. If you specify the string ".obj", you exclude all files with the .obj extension.

Example:

xcopy c:\t1 c:\t2 /EXCLUDE:list-of-excluded-files.txt

and list-of-excluded-files.txt should exist in current folder (otherwise pass full path), with listing of files/folders to exclude - one file/folder per line. In your case that would be:

exclusion.txt

Plotting using a CSV file

This should get you started:

set datafile separator ","
plot 'infile' using 0:1

How to get the mysql table columns data type?

Please use the below mysql query.

SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH 
FROM information_schema.columns 
WHERE table_schema = '<DATABASE NAME>' 
AND table_name = '<TABLE NAME>' 
AND COLUMN_NAME = '<COLOMN NAME>' 

MySql Query Result

CGRectMake, CGPointMake, CGSizeMake, CGRectZero, CGPointZero is unavailable in Swift

In Swift 3, you can simply use CGPoint.zero or CGRect.zero in place of CGRectZero or CGPointZero.

However, in Swift 4, CGRect.zero and 'CGPoint.zero' will work

How to implement the Java comparable interface?

You just have to define that Animal implements Comparable<Animal> i.e. public class Animal implements Comparable<Animal>. And then you have to implement the compareTo(Animal other) method that way you like it.

@Override
public int compareTo(Animal other) {
    return Integer.compare(this.year_discovered, other.year_discovered);
}

Using this implementation of compareTo, animals with a higher year_discovered will get ordered higher. I hope you get the idea of Comparable and compareTo with this example.

How do I find if a string starts with another string in Ruby?

The method mentioned by steenslag is terse, and given the scope of the question it should be considered the correct answer. However it is also worth knowing that this can be achieved with a regular expression, which if you aren't already familiar with in Ruby, is an important skill to learn.

Have a play with Rubular: http://rubular.com/

But in this case, the following ruby statement will return true if the string on the left starts with 'abc'. The \A in the regex literal on the right means 'the beginning of the string'. Have a play with rubular - it will become clear how things work.

'abcdefg' =~  /\Aabc/ 

HTML button onclick event

Having trouble with a button onclick event in jsfiddle?

If so see Onclick event not firing on jsfiddle.net

How do I use this JavaScript variable in HTML?

You can create an element with an id and then assign that length value to that element.

_x000D_
_x000D_
var name = prompt("What's your name?");_x000D_
var lengthOfName = name.length_x000D_
document.getElementById('message').innerHTML = lengthOfName;
_x000D_
<p id='message'></p>
_x000D_
_x000D_
_x000D_

Best practices for SQL varchar column length

VARCHAR(255) and VARCHAR(2) take exactly the same amount of space on disk! So the only reason to limit it is if you have a specific need for it to be smaller. Otherwise make them all 255.

Specifically, when doing sorting, larger column do take up more space, so if that hurts performance, then you need to worry about it and make them smaller. But if you only ever select 1 row from that table, then you can just make them all 255 and it won't matter.

See: What are the optimum varchar sizes for MySQL?

How can I create a table with borders in Android?

Another solution is to use linear layouts and set dividers between rows and cells like this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<View
    android:layout_width="match_parent"
    android:layout_height="1px"
    android:background="#8000"/>

<LinearLayout
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_weight="1">

    <View
        android:layout_width="@dimen/border"
        android:layout_height="match_parent"
        android:background="#8000"
        android:layout_marginTop="1px"
        android:layout_marginBottom="1px"/>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        ></LinearLayout>

    <View
        android:layout_width="@dimen/border"
        android:layout_height="match_parent"
        android:background="#8000"
        android:layout_marginTop="1px"
        android:layout_marginBottom="1px"/>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"></LinearLayout>

    <View
        android:layout_width="@dimen/border"
        android:layout_height="match_parent"
        android:background="#8000"
        android:layout_marginTop="1px"
        android:layout_marginBottom="1px"/>

</LinearLayout>

<View
    android:layout_width="match_parent"
    android:layout_height="1px"
    android:background="#8000"/>

<LinearLayout
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_weight="1">

    <View
        android:layout_width="@dimen/border"
        android:layout_height="match_parent"
        android:background="#8000"
        android:layout_marginTop="1px"
        android:layout_marginBottom="1px"/>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        ></LinearLayout>

    <View
        android:layout_width="@dimen/border"
        android:layout_height="match_parent"
        android:background="#8000"
        android:layout_marginTop="1px"
        android:layout_marginBottom="1px"/>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"></LinearLayout>
    <View
        android:layout_width="@dimen/border"
        android:layout_height="match_parent"
        android:background="#8000"
        android:layout_marginTop="1px"
        android:layout_marginBottom="1px"/>
</LinearLayout>

<View
    android:layout_width="match_parent"
    android:layout_height="1px"
    android:background="#8000"/>
</LinearLayout>

It's a dirty solution, but it's simple and also works with transparent background and borders.

How to delete a specific file from folder using asp.net

This is how I delete files

if ((System.IO.File.Exists(fileName)))
                {
                    System.IO.File.Delete(fileName);
}

Also make sure that the file name you are passing in your delete, is the accurate path

EDIT

You could use the following event instead as well or just use the code in this snippet and use in your method

void GridView1_SelectedIndexChanged(Object sender, EventArgs e)
  {

    // Get the currently selected row using the SelectedRow property.
    GridViewRow row = CustomersGridView.SelectedRow;

    //Debug this line and see what value is returned if it contains the full path.
    //If it does not contain the full path then add the path to the string.
    string fileName = row.Cells[0].Text 

    if(fileName != null || fileName != string.empty)
    {
       if((System.IO.File.Exists(fileName))
           System.IO.File.Delete(fileName);

     }
  }

PHP Warning: PHP Startup: Unable to load dynamic library

In my case, this message started to appear when I updated the php version to 7.4.

To solve it I had to look for the php.ini files found inside the php version folder (/etc/php/7.4/apache2/ && /etc/php/7.4/cli/) checking the lines where the extensions I could see that the extensions gd2 and intl were uncommented.

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

I solved the Access-Control-Allow-Origin error modifying the dataType parameter to dataType:'jsonp' and adding a crossDomain:true

$.ajax({

    url: 'https://www.googleapis.com/moderator/v1/series?key='+key,
    data: myData,
    type: 'GET',
    crossDomain: true,
    dataType: 'jsonp',
    success: function() { alert("Success"); },
    error: function() { alert('Failed!'); },
    beforeSend: setHeader
});

How to check View Source in Mobile Browsers (Both Android && Feature Phone)

This is an old post but still a problem within the Chrome dev tools. I find the best way to check mobile source locally is to open the site locally in Xcode's iOS Simulator. Then from there you open the Safari browser and enable dev tools, if you have not already done this (go to preferences -> advanced -> show develop menu in menu bar). Now you will see the develop option in the main menu and can go to develop -> iOS Simulator -> and the page you have open in Xcode's iOS Simulator will be there. Once you click on it, it will open the web inspector and you can edit as you would normally in the browser dev tools.

I'm afraid this solution will only work on a Mac though as it uses Xcode.

C++ display stack trace on exception

Andrew Grant's answer does not help getting a stack trace of the throwing function, at least not with GCC, because a throw statement does not save the current stack trace on its own, and the catch handler won't have access to the stack trace at that point any more.

The only way - using GCC - to solve this is to make sure to generate a stack trace at the point of the throw instruction, and save that with the exception object.

This method requires, of course, that every code that throws an exception uses that particular Exception class.

Update 11 July 2017: For some helpful code, take a look at cahit beyaz's answer, which points to http://stacktrace.sourceforge.net - I haven't used it yet but it looks promising.

How to use the command update-alternatives --config java

This is how I install jdk

#!/bin/bash
cd /opt/
sudo mkdir java
sudo tar -zxvf ~/Downloads/jdk-8u192-linux-x64.tar.gz
sudo ln -s  jdk1.8.0_192 current
for file in /opt/java/current/bin/*
do
   if [ -x $file ]
   then
      filename=`basename $file`
      sudo update-alternatives --install /usr/bin/$filename $filename $file 20000
      sudo update-alternatives --set $filename $file
      #echo $file $filename
   fi
done

In Jinja2, how do you test if a variable is undefined?

{% if variable is defined %} works to check if something is undefined.

You can get away with using {% if not var1 %} if you default your variables to False eg

class MainHandler(BaseHandler):
    def get(self):
        var1 = self.request.get('var1', False)

Failure during conversion to COFF: file invalid or corrupt

In my case it was just caused because there was not enough space on the disk for cvtres.exe to write the files it had to.

The error was preceded by this line

CVTRES : fatal error CVT1106: cannot write to file

How can I pass a file argument to my bash script using a Terminal command in Linux?

Assuming you do as David Zaslavsky suggests, so that the first argument simply is the program to run (no option-parsing required), you're dealing with the question of how to pass arguments 2 and on to your external program. Here's a convenient way:

#!/bin/bash
ext_program="$1"
shift
"$ext_program" "$@"

The shift will remove the first argument, renaming the rest ($2 becomes $1, and so on).$@` refers to the arguments, as an array of words (it must be quoted!).

If you must have your --file syntax (for example, if there's a default program to run, so the user doesn't necessarily have to supply one), just replace ext_program="$1" with whatever parsing of $1 you need to do, perhaps using getopt or getopts.

If you want to roll your own, for just the one specific case, you could do something like this:

if [ "$#" -gt 0 -a "${1:0:6}" == "--file" ]; then
    ext_program="${1:7}"
else
    ext_program="default program"
fi

Internal vs. Private Access Modifiers

internal members are accessible within the assembly (only accessible in the same project)

private members are accessible within the same class

Example for Beginners

There are 2 projects in a solution (Project1, Project2) and Project1 has a reference to Project2.

  • Public method written in Project2 will be accessible in Project2 and the Project1
  • Internal method written in Project2 will be accessible in Project2 only but not in Project1
  • private method written in class1 of Project2 will only be accessible to the same class. It will neither be accessible in other classes of Project 2 not in Project 1.

Setting the JVM via the command line on Windows

You should be able to do this via the command line arguments, assuming these are Sun VMs installed using the usual Windows InstallShield mechanisms with the JVM finder EXE in system32.

Type java -help for the options. In particular, see:

-version:<value>
              require the specified version to run
-jre-restrict-search | -jre-no-restrict-search
              include/exclude user private JREs in the version search

Safely limiting Ansible playbooks to a single machine?

This shows how to run the playbooks on the target server itself.

This is a bit trickier if you want to use a local connection. But this should be OK if you use a variable for the hosts setting and in the hosts file create a special entry for localhost.

In (all) playbooks have the hosts: line set to:

- hosts: "{{ target | default('no_hosts')}}"

In the inventory hosts file add an entry for the localhost which sets the connection to be local:

[localhost]
127.0.0.1  ansible_connection=local

Then on the command line run commands explicitly setting the target - for example:

$ ansible-playbook --extra-vars "target=localhost" test.yml

This will also work when using ansible-pull:

$ ansible-pull -U <git-repo-here> -d ~/ansible --extra-vars "target=localhost" test.yml

If you forget to set the variable on the command line the command will error safely (as long as you've not created a hosts group called 'no_hosts'!) with a warning of:

skipping: no hosts matched

And as mentioned above you can target a single machine (as long as it is in your hosts file) with:

$ ansible-playbook --extra-vars "target=server.domain" test.yml

or a group with something like:

$ ansible-playbook --extra-vars "target=web-servers" test.yml

Convert 4 bytes to int

If you have them already in a byte[] array, you can use:

int result = ByteBuffer.wrap(bytes).getInt();

source: here

What does auto do in margin:0 auto?

margin-top:0;
margin-bottom:0;
margin-left:auto;
margin-right:auto;

0 is for top-bottom and auto for left-right. The browser sets the margin.

Jump to function definition in vim

Use gd or gD while placing the cursor on any variable in your program.

  1. gd will take you to the local declaration.
  2. gD will take you to the global declaration.

more navigation options can be found in here.

Use cscope for cross referencing large project such as the linux kernel.

Return multiple fields as a record in PostgreSQL with PL/pgSQL

If you have a table with this exact record layout, use its name as a type, otherwise you will have to declare the type explicitly:

CREATE OR REPLACE FUNCTION get_object_fields
        (
        name text
        )
RETURNS mytable
AS
$$
        DECLARE f1 INT;
        DECLARE f2 INT;
        …
        DECLARE f8 INT;
        DECLARE retval mytable;
        BEGIN
        -- fetch fields f1, f2 and f3 from table t1
        -- fetch fields f4, f5 from table t2
        -- fetch fields f6, f7 and f8 from table t3
                retval := (f1, f2, …, f8);
                RETURN retval;
        END
$$ language plpgsql; 

What does the question mark operator mean in Ruby?

It may be worth pointing out that ?s are only allowed in method names, not variables. In the process of learning Ruby, I assumed that ? designated a boolean return type so I tried adding them to flag variables, leading to errors. This led to me erroneously believing for a while that there was some special syntax involving ?s.

Relevant: Why can't a variable name end with `?` while a method name can?

Python string.join(list) on object array rather than string array

I know this is a super old post, but I think what is missed is overriding __repr__, so that __repr__ = __str__, which is the accepted answer of this question marked duplicate.

IIs Error: Application Codebehind=“Global.asax.cs” Inherits=“nadeem.MvcApplication”

The only solution that worked for me

  1. Run, Type command %Temp% -> Deleting "Temporary ASP.NET Files".

Other solutions I have tried, which didn't work.

  1. Cleaning/Rebuilding

  2. Cleaning bin, obj folders

  3. Changing namespace

Python 3.1.1 string to hex

binascii methodes are easier by the way

>>> import binascii
>>> x=b'test'
>>> x=binascii.hexlify(x)
>>> x
b'74657374'
>>> y=str(x,'ascii')
>>> y
'74657374'
>>> x=binascii.unhexlify(x)
>>> x
b'test'
>>> y=str(x,'ascii')
>>> y
'test'

Hope it helps. :)

Check if item is in an array / list

Use a lambda function.

Let's say you have an array:

nums = [0,1,5]

Check whether 5 is in nums in Python 3.X:

(len(list(filter (lambda x : x == 5, nums))) > 0)

Check whether 5 is in nums in Python 2.7:

(len(filter (lambda x : x == 5, nums)) > 0)

This solution is more robust. You can now check whether any number satisfying a certain condition is in your array nums.

For example, check whether any number that is greater than or equal to 5 exists in nums:

(len(filter (lambda x : x >= 5, nums)) > 0)

How to disable compiler optimizations in gcc?

You can disable optimizations if you pass -O0 with the gcc command-line.

E.g. to turn a .C file into a .S file call:

gcc -O0 -S test.c

'Missing recommended icon file - The bundle does not contain an app icon for iPhone / iPod Touch of exactly '120x120' pixels, in .png format'

In my case, my App icon files were not in the camel case notation. For example:

My Filename: Appicon57x57

Should be: AppIcon57x57 (note the capital 'i' here)

So, in my case the solution was this:

  1. Remove all the icon files from the Asset Catalog.
  2. Rename the file as mentioned above.
  3. Add the renamed files back to the Asset Catalog again.

This should fix the problem.

Disabling the long-running-script message in Internet Explorer

In my case, while playing video, I needed to call a function everytime currentTime of video updates. So I used timeupdate event of video and I came to know that it was fired at least 4 times a second (depends on the browser you use, see this). So I changed it to call a function every second like this:

var currentIntTime = 0;

var someFunction = function() {
    currentIntTime++;
    // Do something here
} 
vidEl.on('timeupdate', function(){
    if(parseInt(vidEl.currentTime) > currentIntTime) {
        someFunction();
    }
});

This reduces calls to someFunc by at least 1/3 and it may help your browser to behave normally. It did for me !!!

SQL Combine Two Columns in Select Statement

SELECT StaffId,(Title+''+FirstName+''+LastName) AS FullName 
FROM StaffInformation

Where do you write with in the brackets this will be appear in the one single column. Where do you want a dot into the middle of the Title and First Name write syntax below,

SELECT StaffId,(Title+'.'+FirstName+''+LastName) AS FullName 
FROM StaffInformation

These syntax works with MS SQL Server 2008 R2 Express Edition.

Is there a Google Sheets formula to put the name of the sheet into a cell?

You have 2 options, and I am not sure if I am a fan of either of them, but that is my opinion. You may feel differently:

Option 1: Force the function to run.

A function in a cell does not run unless it references a cell that has changed. Changing a sheet name does not trigger any functions in the spreadsheet. But we can force the function to run by passing a range to it and whenever an item in that range changes, the function will trigger.

You can use the below script to create a custom function which will retrieve the name:

function mySheetName() {
  var key = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet().getName();
  return key;
}

and in the cell place the following:

=mySheetName(A1:Z)

Now if any value in a cell in that passed range changes the script will run. This takes a second to run the script and sets a message in the cell each time any value is changed so this could become annoying very quickly. As already mentioned, it also requires a change in the range to cause it to trigger, so not really helpful on a fairly static file.

Option 2: Use the OnChange Event

While the run time feels better than the above option, and this does not depend on a value changing in the spreadsheet's cells, I do not like this because it forces where the name goes. You could use a Utilities sheet to define this location in various sheets if you wish. Below is the basic idea and may get you started if you like this option.

The OnChange event is triggered when the sheet name is changed. You can make the code below more sophisticated to check for errors, check the sheet ID to only work on a given sheet, etc. The basic code, however, is:

function setSheetName(e) {
  var key = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet().getName();
  SpreadsheetApp.getActiveSpreadsheet().getActiveSheet().getRange('K1').setValue(key);
}

Once you have saved the code, in the script editor set the Current Project's On Change Trigger to this function. It will write the sheet name to cell K1 on any change event. To set the trigger, select Current project's triggers under the Edit menu.

Error 'tunneling socket' while executing npm install

I have faced similar issue and none of the above solution worked as I was in protected network.

To overcome this, I have installed "Fiddler" tool from Telerik, after installation start Fiddler and start installation of Protractor again.

Hope this will resolve your issue.

Thanks.

Stop executing further code in Java

Just do:

public void onClick() {
    if(condition == true) {
        return;
    }
    string.setText("This string should not change if condition = true");
}

It's redundant to write if(condition == true), just write if(condition) (This way, for example, you'll not write = by mistake).

How to refresh app upon shaking the device?

I really liked Peterdk's answer. I took it upon myself to make a coulpe of tweaks to his code .

file: ShakeDetector.java

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.util.FloatMath;

public class ShakeDetector implements SensorEventListener {

    // The gForce that is necessary to register as shake. Must be greater than 1G (one earth gravity unit)
    private static final float SHAKE_THRESHOLD_GRAVITY = 2.7F;
    private static final int SHAKE_SLOP_TIME_MS = 500;
    private static final int SHAKE_COUNT_RESET_TIME_MS = 3000;

    private OnShakeListener mListener;
    private long mShakeTimestamp;
    private int mShakeCount;

    public void setOnShakeListener(OnShakeListener listener) {
        this.mListener = listener;
    }

    public interface OnShakeListener {
        public void onShake(int count);
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // ignore
    }

    @Override
    public void onSensorChanged(SensorEvent event) {

        if (mListener != null) {
            float x = event.values[0];
            float y = event.values[1];
            float z = event.values[2];

            float gX = x / SensorManager.GRAVITY_EARTH;
            float gY = y / SensorManager.GRAVITY_EARTH;
            float gZ = z / SensorManager.GRAVITY_EARTH;

            // gForce will be close to 1 when there is no movement.
            float gForce = FloatMath.sqrt(gX * gX + gY * gY + gZ * gZ);

            if (gForce > SHAKE_THRESHOLD_GRAVITY) {
                final long now = System.currentTimeMillis();
                // ignore shake events too close to each other (500ms)
                if (mShakeTimestamp + SHAKE_SLOP_TIME_MS > now ) {
                    return;
                }

                // reset the shake count after 3 seconds of no shakes
                if (mShakeTimestamp + SHAKE_COUNT_RESET_TIME_MS < now ) {
                    mShakeCount = 0;
                }

                mShakeTimestamp = now;
                mShakeCount++;

                mListener.onShake(mShakeCount);
            }
        }
    }
}

Also, don't forget that you need to register an instance of the ShakeDetector with the SensorManager.

// ShakeDetector initialization
mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mShakeDetector = new ShakeDetector();
mShakeDetector.setOnShakeListener(new OnShakeListener() {

    @Override
    public void onShake(int count) {
            handleShakeEvent(count); 
        }
    });

mSensorManager.registerListener(mShakeDetector, mAccelerometer, SensorManager.SENSOR_DELAY_UI);

running php script (php function) in linux bash

php -f test.php

See the manual for full details of running PHP from the command line

How to view DLL functions?

Use dotPeek by JetBrains.

https://www.jetbrains.com/decompiler/

dotPeek is a free tool based on ReSharper. It can reliably decompile any .NET assembly into C# or IL code.

Input Type image submit form value?

Some browsers (IIRC it is just some versions of Internet Explorer) only send the co-ordinates of the image map (in name.x and name.y) and ignore the value. This is a bug.

The workarounds are to either:

  • Have only one submit button and use a hidden input to sent the value
  • Use regular submit buttons instead of image maps
  • Use unique names instead of values and check for the presence of name.x / name.y

How do I display the current value of an Android Preference in the Preference summary?

If you are using AndroidX you can use a custom SummaryProvider. This approach can be used for any Preference.

Example from documentation (Java):

EditTextPreference countingPreference = (EditTextPreference) findPreference("counting");

countingPreference.setSummaryProvider(new SummaryProvider<EditTextPreference>() {
    @Override
    public CharSequence provideSummary(EditTextPreference preference) {
        String text = preference.getText();
        if (TextUtils.isEmpty(text)){
            return "Not set";
        }
        return "Length of saved value: " + text.length();
    }
});

Example from documentation (Kotlin):

val countingPreference = findPreference("counting") as EditTextPreference

countingPreference.summaryProvider = SummaryProvider<EditTextPreference> { preference ->
    val text = preference.text
    if (TextUtils.isEmpty(text)) {
        "Not set"
    } else {
        "Length of saved value: " + text.length
    }
}

$(document).ready(function(){ Uncaught ReferenceError: $ is not defined

It seems you don't import jquery. Those $ functions come with this non standard (but very useful) library.

Read the tutorial there : http://docs.jquery.com/Tutorials:Getting_Started_with_jQuery It starts with how to import the library.

Indenting code in Sublime text 2?

This is my configuration for sublime-keymap:

[
  {
    "keys": [",+=+="],
    "command": "reindent",
    "args": {
      "single_line": false
    }
  }
]

For vim people, just use ,== to reindent the whole file.

What is the difference between Session.Abandon() and Session.Clear()

This is sort of covered by the various responses above, but the first time I read this article I missed an important fact, which led to a minor bug in my code...

Session.Clear() will CLEAR the values of all the keys but will NOT cause the session end event to fire.

Session.Abandon() will NOT clear the values on the current request. IF another page is requested, the values will be gone for that one. However, abandon WILL throw the event.

So, in my case (and perhaps in yours?), I needed Clear() followed by Abandon().

How to view file history in Git?

Looks like you want git diff and/or git log. Also check out gitk

gitk path/to/file
git diff path/to/file
git log path/to/file

How do I create a MessageBox in C#?

In the System.Windows.Forms class, you can find more on the MSDN page for this here. Among other things you can control the message box text, title, default button, and icons. Since you didn't specify, if you are trying to do this in a webpage you should look at triggering the javascript alert("my message"); or confirm("my question"); functions.

Is it possible to convert char[] to char* in C?

If you have char[] c then you can do char* d = &c[0] and access element c[1] by doing *(d+1), etc.

Spring MVC Controller redirect using URL parameters instead of in response

You can have processForm() return a View object instead, and have it return the concrete type RedirectView which has a parameter for setExposeModelAttributes().

When you return a view name prefixed with "redirect:", Spring MVC transforms this to a RedirectView object anyway, it just does so with setExposeModelAttributes to true (which I think is an odd value to default to).

AngularJS ng-style with a conditional expression

EDIT:

Ok i was previously not aware that AngularJS usually refers to Angular v1 version and only Angular to Angular v2+

This answer only applies for Angular

Leaving this here for future reference..


Not sure how it works for you guys but on Angular 9 i have to wrap ngStyle in brackets like this:

[ng-style]="{ 'width' : (myObject.value == 'ok') ? '100%' : '0%' }"

Otherwise it doesn't work

Creating a Custom Event

Based on @ionden's answer, the call to the delegate could be simplified using null propagation since C# 6.0.

Your code would simply be:

class MyClass {
    public event EventHandler MyEvent;

    public void Method() {
        MyEvent?.Invoke(this, EventArgs.Empty);
    }
}

Use it like this:

MyClass myObject = new MyClass();
myObject.MyEvent += new EventHandler(myObject_MyEvent);
myObject.Method();

Can a foreign key be NULL and/or duplicate?

Short answer: Yes, it can be NULL or duplicate.

I want to explain why a foreign key might need to be null or might need to be unique or not unique. First remember a Foreign key simply requires that the value in that field must exist first in a different table (the parent table). That is all an FK is by definition. Null by definition is not a value. Null means that we do not yet know what the value is.

Let me give you a real life example. Suppose you have a database that stores sales proposals. Suppose further that each proposal only has one sales person assigned and one client. So your proposal table would have two foreign keys, one with the client ID and one with the sales rep ID. However, at the time the record is created, a sales rep is not always assigned (because no one is free to work on it yet), so the client ID is filled in but the sales rep ID might be null. In other words, usually you need the ability to have a null FK when you may not know its value at the time the data is entered, but you do know other values in the table that need to be entered. To allow nulls in an FK generally all you have to do is allow nulls on the field that has the FK. The null value is separate from the idea of it being an FK.

Whether it is unique or not unique relates to whether the table has a one-one or a one-many relationship to the parent table. Now if you have a one-one relationship, it is possible that you could have the data all in one table, but if the table is getting too wide or if the data is on a different topic (the employee - insurance example @tbone gave for instance), then you want separate tables with a FK. You would then want to make this FK either also the PK (which guarantees uniqueness) or put a unique constraint on it.

Most FKs are for a one to many relationship and that is what you get from a FK without adding a further constraint on the field. So you have an order table and the order details table for instance. If the customer orders ten items at one time, he has one order and ten order detail records that contain the same orderID as the FK.

Auto-increment primary key in SQL tables

Right-click on the table in SSMS, 'Design' it, and click on the id column. In the properties, set the identity to be seeded @ e.g. 1 and to have increment of 1 - save and you're done.

how much memory can be accessed by a 32 bit machine?

Yes, on a 32bit machine the maximum amount of memory usable is around 4GB. Actually, depending on the OS it might be less due to parts of the address space being reserved: On Windows you can only use 3.5GB for example.

On 64bit you can indeed address 2^64 bytes of memory. Not that you'll ever have those - but then again, a long time ago the same thing was said about ever needing more than 640kb of memory...

List all environment variables from the command line

To list all environment variables in PowerShell:

Get-ChildItem Env:

Or as suggested by user797717 to avoid output truncation:

Get-ChildItem Env: | Format-Table -Wrap -AutoSize

Source: Creating and Modifying Environment Variables (Windows PowerShell Tip of the Week)

How to display HTML <FORM> as inline element?

Just use the style float: left in this way:

<p style="float: left"> Lorem Ipsum </p> 
<form style="float: left">
   <input  type='submit'/>
</form>
<p style="float: left"> Lorem Ipsum </p>

Force youtube embed to start in 720p

Youtube doesn't support playback quality anymore

Youtube doesn't support playback quality anymore

Best practices for API versioning?

We found it practical and useful to put the version in the URL. It makes it easy to tell what you're using at a glance. We do alias /foo to /foo/(latest versions) for ease of use, shorter / cleaner URLs, etc, as the accepted answer suggests.

Keeping backwards compatibility forever is often cost-prohibitive and/or very difficult. We prefer to give advanced notice of deprecation, redirects like suggested here, docs, and other mechanisms.

Creating an abstract class in Objective-C

This thread is kind of old, and most of what I want to share is already here.

However, my favorite method is not mentioned, and AFAIK there’s no native support in the current Clang, so here I go…

First, and foremost (as others have pointed out already) abstract classes are something very uncommon in Objective-C — we usually use composition (sometimes through delegation) instead. This is probably the reason why such a feature doesn’t already exist in the language/compiler — apart from @dynamic properties, which IIRC have been added in ObjC 2.0 accompanying the introduction of CoreData.

But given that (after careful assessment of your situation!) you have come to the conclusion that delegation (or composition in general) isn’t well suited to solving your problem, here’s how I do it:

  1. Implement every abstract method in the base class.
  2. Make that implementation [self doesNotRecognizeSelector:_cmd];
  3. …followed by __builtin_unreachable(); to silence the warning you’ll get for non-void methods, telling you “control reached end of non-void function without a return”.
  4. Either combine steps 2. and 3. in a macro, or annotate -[NSObject doesNotRecognizeSelector:] using __attribute__((__noreturn__)) in a category without implementation so as not to replace the original implementation of that method, and include the header for that category in your project’s PCH.

I personally prefer the macro version as that allows me to reduce the boilerplate as much as possible.

Here it is:

// Definition:
#define D12_ABSTRACT_METHOD {\
 [self doesNotRecognizeSelector:_cmd]; \
 __builtin_unreachable(); \
}

// Usage (assuming we were Apple, implementing the abstract base class NSString):
@implementation NSString

#pragma mark - Abstract Primitives
- (unichar)characterAtIndex:(NSUInteger)index D12_ABSTRACT_METHOD
- (NSUInteger)length D12_ABSTRACT_METHOD
- (void)getCharacters:(unichar *)buffer range:(NSRange)aRange D12_ABSTRACT_METHOD

#pragma mark - Concrete Methods
- (NSString *)substringWithRange:(NSRange)aRange
{
    if (aRange.location + aRange.length >= [self length])
        [NSException raise:NSInvalidArgumentException format:@"Range %@ exceeds the length of %@ (%lu)", NSStringFromRange(aRange), [super description], (unsigned long)[self length]];

    unichar *buffer = (unichar *)malloc(aRange.length * sizeof(unichar));
    [self getCharacters:buffer range:aRange];

    return [[[NSString alloc] initWithCharactersNoCopy:buffer length:aRange.length freeWhenDone:YES] autorelease];
}
// and so forth…

@end

As you can see, the macro provides the full implementation of the abstract methods, reducing the necessary amount of boilerplate to an absolute minimum.

An even better option would be to lobby the Clang team to providing a compiler attribute for this case, via feature requests. (Better, because this would also enable compile-time diagnostics for those scenarios where you subclass e.g. NSIncrementalStore.)

Why I Choose This Method

  1. It get’s the job done efficiently, and somewhat conveniently.
  2. It’s fairly easy to understand. (Okay, that __builtin_unreachable() may surprise people, but it’s easy enough to understand, too.)
  3. It cannot be stripped in release builds without generating other compiler warnings, or errors — unlike an approach that’s based on one of the assertion macros.

That last point needs some explanation, I guess:

Some (most?) people strip assertions in release builds. (I disagree with that habit, but that’s another story…) Failing to implement a required method — however — is bad, terrible, wrong, and basically the end of the universe for your program. Your program cannot work correctly in this regard because it is undefined, and undefined behavior is the worst thing ever. Hence, being able to strip those diagnostics without generating new diagnostics would be completely unacceptable.

It’s bad enough that you cannot obtain proper compile-time diagnostics for such programmer errors, and have to resort to at-run-time discovery for these, but if you can plaster over it in release builds, why try having an abstract class in the first place?

Excel Calculate the date difference from today from a cell of "7/6/2012 10:26:42"

If that's a valid date/time entry then excel simply stores it as a number (days are integers and the time is the decimal part) so you can do a simple subtraction.

I'm not sure if 7/6 is 7th June or 6th July, assuming the latter then it's a future date so you can get the difference in days with

=INT(A1-TODAY())

Make sure you format result cell as general or number (not date)

How to make method call another one in classes?

Because the Method2 is static, all you have to do is call like this:

public class AllMethods
{
    public static void Method2()
    {
        // code here
    }
}

class Caller
{
    public static void Main(string[] args)
    {
        AllMethods.Method2();
    }
}

If they are in different namespaces you will also need to add the namespace of AllMethods to caller.cs in a using statement.

If you wanted to call an instance method (non-static), you'd need an instance of the class to call the method on. For example:

public class MyClass
{
    public void InstanceMethod() 
    { 
        // ...
    }
}

public static void Main(string[] args)
{
    var instance = new MyClass();
    instance.InstanceMethod();
}

Update

As of C# 6, you can now also achieve this with using static directive to call static methods somewhat more gracefully, for example:

// AllMethods.cs
namespace Some.Namespace
{
    public class AllMethods
    {
        public static void Method2()
        {
            // code here
        }
    }
}

// Caller.cs
using static Some.Namespace.AllMethods;

namespace Other.Namespace
{
    class Caller
    {
        public static void Main(string[] args)
        {
            Method2(); // No need to mention AllMethods here
        }
    }
}

Further Reading

Scala list concatenation, ::: vs ++

Legacy. List was originally defined to be functional-languages-looking:

1 :: 2 :: Nil // a list
list1 ::: list2  // concatenation of two lists

list match {
  case head :: tail => "non-empty"
  case Nil          => "empty"
}

Of course, Scala evolved other collections, in an ad-hoc manner. When 2.8 came out, the collections were redesigned for maximum code reuse and consistent API, so that you can use ++ to concatenate any two collections -- and even iterators. List, however, got to keep its original operators, aside from one or two which got deprecated.

Are there any standard exit status codes in Linux?

There are no standard exit codes, aside from 0 meaning success. Non-zero doesn't necessarily mean failure either.

stdlib.h does define EXIT_FAILURE as 1 and EXIT_SUCCESS as 0, but that's about it.

The 11 on segfault is interesting, as 11 is the signal number that the kernel uses to kill the process in the event of a segfault. There is likely some mechanism, either in the kernel or in the shell, that translates that into the exit code.

Changing the resolution of a VNC session in linux

I think that depends on your window manager.

I'm a windows user, so this might be a wrong guess, but: Isn't there something called X-Server running on linux machines - at least on ones that might be interesting targets for VNC - that you can connect to with "X-Clients"?

VNC just takes everything that's on the screen and "tunnels it through your network". If I'm not totally wrong then the "X" protocol should give you the chance to use your client's desktop resolution.

Give X-Server on Wikipedia a try, that might give you a rough overview.

How do you save/store objects in SharedPreferences on Android?

I know this thread is bit old. But I'm going to post this anyway hoping it might help someone. We can store fields of any Object to shared preference by serializing the object to String. Here I have used GSON for storing any object to shared preference.

Save Object to Preference :

public static void saveObjectToSharedPreference(Context context, String preferenceFileName, String serializedObjectKey, Object object) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(preferenceFileName, 0);
    SharedPreferences.Editor sharedPreferencesEditor = sharedPreferences.edit();
    final Gson gson = new Gson();
    String serializedObject = gson.toJson(object);
    sharedPreferencesEditor.putString(serializedObjectKey, serializedObject);
    sharedPreferencesEditor.apply();
}

Retrieve Object from Preference:

public static <GenericClass> GenericClass getSavedObjectFromPreference(Context context, String preferenceFileName, String preferenceKey, Class<GenericClass> classType) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(preferenceFileName, 0);
    if (sharedPreferences.contains(preferenceKey)) {
        final Gson gson = new Gson();
        return gson.fromJson(sharedPreferences.getString(preferenceKey, ""), classType);
    }
    return null;
}

Note :

Remember to add compile 'com.google.code.gson:gson:2.6.2' to dependencies in your gradle.

Example :

//assume SampleClass exists
SampleClass mObject = new SampleObject();

//to store an object
saveObjectToSharedPreference(context, "mPreference", "mObjectKey", mObject);

//to retrive object stored in preference
mObject = getSavedObjectFromPreference(context, "mPreference", "mObjectKey", SampleClass.class);

Update:

As @Sharp_Edge pointed out in comments, the above solution does not work with List.

A slight modification to the signature of getSavedObjectFromPreference() - from Class<GenericClass> classType to Type classType will make this solution generalized. Modified function signature,

public static <GenericClass> GenericClass getSavedObjectFromPreference(Context context, String preferenceFileName, String preferenceKey, Type classType)

For invoking,

getSavedObjectFromPreference(context, "mPreference", "mObjectKey", (Type) SampleClass.class)

Happy Coding!

How do I calculate square root in Python?

You can use NumPy to calculate square roots of arrays:

 import numpy as np
 np.sqrt([1, 4, 9])

How could I create a list in c++?

Create list using C++ templates

i.e

template <class T> struct Node 
{
    T data;
    Node * next;
};
    
template <class T> class List 
{
    Node<T> *head,*tail;
        
    public: 
        void push(T const&);  // push element 
        void pop();           // pop element 
        bool empty()          // return true if empty. 
}; 

Then you can write the code like:

List<MyClass>;

The type T is not dynamic in run time.It is only for the compile time.

For complete example click here.

For C++ templates tutorial click here.

Java Synchronized list

Yes, it will work fine as you have synchronized the list . I would suggest you to use CopyOnWriteArrayList.

CopyOnWriteArrayList<String> cpList=new CopyOnWriteArrayList<String>(new ArrayList<String>());

    void remove(String item)
    {
         do something; (doesn't work on the list)
                 cpList..remove(item);
    }

Get Unix timestamp with C++

The most common advice is wrong, you can't just rely on time(). That's used for relative timing: ISO C++ doesn't specify that 1970-01-01T00:00Z is time_t(0)

What's worse is that you can't easily figure it out, either. Sure, you can find the calendar date of time_t(0) with gmtime, but what are you going to do if that's 2000-01-01T00:00Z ? How many seconds were there between 1970-01-01T00:00Z and 2000-01-01T00:00Z? It's certainly no multiple of 60, due to leap seconds.

Keras, how do I predict after I trained a model?

I trained a neural network in Keras to perform non linear regression on some data. This is some part of my code for testing on new data using previously saved model configuration and weights.

fname = r"C:\Users\tauseef\Desktop\keras\tutorials\BestWeights.hdf5"
modelConfig = joblib.load('modelConfig.pkl')
recreatedModel = Sequential.from_config(modelConfig)
recreatedModel.load_weights(fname)
unseenTestData = np.genfromtxt(r"C:\Users\tauseef\Desktop\keras\arrayOf100Rows257Columns.txt",delimiter=" ")
X_test = unseenTestData
standard_scalerX = StandardScaler()
standard_scalerX.fit(X_test)
X_test_std = standard_scalerX.transform(X_test)
X_test_std = X_test_std.astype('float32')
unseenData_predictions = recreatedModel.predict(X_test_std)

How to achieve pagination/table layout with Angular.js?

I use this solution:

It's a bit more concise since I use: ng-repeat="obj in objects | filter : paginate" to filter the rows. Also made it working with $resource:

http://plnkr.co/edit/79yrgwiwvan3bAG5SnKx?p=preview

Length of array in function argument

As stated by @Will, the decay happens during the parameter passing. One way to get around it is to pass the number of elements. To add onto this, you may find the _countof() macro useful - it does the equivalent of what you've done ;)

How do I set up IntelliJ IDEA for Android applications?

The 5th step in "New Project' has apparently changed slightly since.

Where it says android sdk then has the drop down menu that says none, there is no longer a 'new' button.

  • 5.)

    • a.)click the ... to the right of none.
    • b.)click the + in the top left of new window dialog. (Add new Sdk)
    • c.)click android sdk from drop down menu
    • d.)select home directory for your android sdk
    • e.)select java sdk version you want to use
    • f.)select android build target.
    • g.)hit ok!

Why does flexbox stretch my image rather than retaining aspect ratio?

The key attribute is align-self: center:

_x000D_
_x000D_
.container {_x000D_
  display: flex;_x000D_
  flex-direction: column;_x000D_
}_x000D_
_x000D_
img {_x000D_
  max-width: 100%;_x000D_
}_x000D_
_x000D_
img.align-self {_x000D_
  align-self: center;_x000D_
}
_x000D_
<div class="container">_x000D_
    <p>Without align-self:</p>_x000D_
    <img src="http://i.imgur.com/NFBYJ3hs.jpg" />_x000D_
    <p>With align-self:</p>_x000D_
    <img class="align-self" src="http://i.imgur.com/NFBYJ3hs.jpg" />_x000D_
</div>
_x000D_
_x000D_
_x000D_

Team Build Error: The Path ... is already mapped to workspace

Simply delete the workspace:

workspace /delete "the-workspace-name"

Implode an array with JavaScript?

For future reference, if you want to mimic the behaviour of PHP's implode() when no delimiter is specified (literally just join the pieces together), you need to pass an empty string into Javascript's join() otherwise it defaults to using commas as delimiters:

var bits = ['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd'];
alert(bits.join());    // H,e,l,l,o, ,W,o,r,l,d
alert(bits.join(''));  // Hello World

Cannot find Dumpbin.exe

A little refresh as for the Visual Studio 2015.

DUMPBIN is being shipped within Common Tools for Visual C++, so be sure to select this feature in the process of installation of Visual Studio. The utility resides at:

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\

It become available within Developer Command Prompt for VS 2015, which can be executed from Start Menu:

Visual Studio 2015 \ Visual Studio Tools \ Developer Command Prompt for VS2015

If you want to make it available in the regular command prompt, then add the utility's location to the PATH environment variable on your machine.

enter image description here

PHP Warning: mysqli_connect(): (HY000/2002): Connection refused

In case anyone else comes by this issue, the default port on MAMP for mysql is 8889, but the port that php expects to use for mysql is 3306. So you need to open MAMP, go to preferences, and change the MAMP mysql port to 3306, then restart the mysql server. Now the connection should be successful with host=localhost, user=root, pass=root.

How to reset index in a pandas dataframe?

Another solutions are assign RangeIndex or range:

df.index = pd.RangeIndex(len(df.index))

df.index = range(len(df.index))

It is faster:

df = pd.DataFrame({'a':[8,7], 'c':[2,4]}, index=[7,8])
df = pd.concat([df]*10000)
print (df.head())

In [298]: %timeit df1 = df.reset_index(drop=True)
The slowest run took 7.26 times longer than the fastest. This could mean that an intermediate result is being cached.
10000 loops, best of 3: 105 µs per loop

In [299]: %timeit df.index = pd.RangeIndex(len(df.index))
The slowest run took 15.05 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 7.84 µs per loop

In [300]: %timeit df.index = range(len(df.index))
The slowest run took 7.10 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 14.2 µs per loop

Wait until page is loaded with Selenium WebDriver for Python

As mentioned in the answer from David Cullen, I've always seen recommendations to use a line like the following one:

element_present = EC.presence_of_element_located((By.ID, 'element_id'))
WebDriverWait(driver, timeout).until(element_present)

It was difficult for me to find somewhere all the possible locators that can be used with the By, so I thought it would be useful to provide the list here. According to Web Scraping with Python by Ryan Mitchell:

ID

Used in the example; finds elements by their HTML id attribute

CLASS_NAME

Used to find elements by their HTML class attribute. Why is this function CLASS_NAME not simply CLASS? Using the form object.CLASS would create problems for Selenium's Java library, where .class is a reserved method. In order to keep the Selenium syntax consistent between different languages, CLASS_NAME was used instead.

CSS_SELECTOR

Finds elements by their class, id, or tag name, using the #idName, .className, tagName convention.

LINK_TEXT

Finds HTML tags by the text they contain. For example, a link that says "Next" can be selected using (By.LINK_TEXT, "Next").

PARTIAL_LINK_TEXT

Similar to LINK_TEXT, but matches on a partial string.

NAME

Finds HTML tags by their name attribute. This is handy for HTML forms.

TAG_NAME

Finds HTML tags by their tag name.

XPATH

Uses an XPath expression ... to select matching elements.

How do you parse and process HTML/XML in PHP?

Just use DOMDocument->loadHTML() and be done with it. libxml's HTML parsing algorithm is quite good and fast, and contrary to popular belief, does not choke on malformed HTML.

Remove legend ggplot 2.2

There might be another solution to this:
Your code was:

geom_point(aes(..., show.legend = FALSE))

You can specify the show.legend parameter after the aes call:

geom_point(aes(...), show.legend = FALSE)

then the corresponding legend should disappear

Conditional Binding: if let error – Initializer for conditional binding must have Optional type

if let/if var optional binding only works when the result of the right side of the expression is an optional. If the result of the right side is not an optional, you can not use this optional binding. The point of this optional binding is to check for nil and only use the variable if it's non-nil.

In your case, the tableView parameter is declared as the non-optional type UITableView. It is guaranteed to never be nil. So optional binding here is unnecessary.

func tableView(tableView: UITableView, commitEditingStyle editingStyle:UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == .Delete {
        // Delete the row from the data source
        myData.removeAtIndex(indexPath.row)
        tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)

All we have to do is get rid of the if let and change any occurrences of tv within it to just tableView.

JavaScript query string

You can extract the key/value pairs from the location.search property, this property has the part of the URL that follows the ? symbol, including the ? symbol.

function getQueryString() {
  var result = {}, queryString = location.search.slice(1),
      re = /([^&=]+)=([^&]*)/g, m;

  while (m = re.exec(queryString)) {
    result[decodeURIComponent(m[1])] = decodeURIComponent(m[2]);
  }

  return result;
}

// ...
var myParam = getQueryString()["myParam"];

Android: Getting a file URI from a content URI?

Inspired answers are Jason LaBrun & Darth Raven. Trying already answered approaches led me to below solution which may mostly cover cursor null cases & conversion from content:// to file://

To convert file, read&write the file from gained uri

public static Uri getFilePathFromUri(Uri uri) throws IOException {
    String fileName = getFileName(uri);
    File file = new File(myContext.getExternalCacheDir(), fileName);
    file.createNewFile();
    try (OutputStream outputStream = new FileOutputStream(file);
         InputStream inputStream = myContext.getContentResolver().openInputStream(uri)) {
        FileUtil.copyStream(inputStream, outputStream); //Simply reads input to output stream
        outputStream.flush();
    }
    return Uri.fromFile(file);
}

To get filename use, it will cover cursor null case

public static String getFileName(Uri uri) {
    String fileName = getFileNameFromCursor(uri);
    if (fileName == null) {
        String fileExtension = getFileExtension(uri);
        fileName = "temp_file" + (fileExtension != null ? "." + fileExtension : "");
    } else if (!fileName.contains(".")) {
        String fileExtension = getFileExtension(uri);
        fileName = fileName + "." + fileExtension;
    }
    return fileName;
}

There is good option to converting from mime type to file extention

 public static String getFileExtension(Uri uri) {
    String fileType = myContext.getContentResolver().getType(uri);
    return MimeTypeMap.getSingleton().getExtensionFromMimeType(fileType);
}

Cursor to obtain name of file

public static String getFileNameFromCursor(Uri uri) {
    Cursor fileCursor = myContext.getContentResolver().query(uri, new String[]{OpenableColumns.DISPLAY_NAME}, null, null, null);
    String fileName = null;
    if (fileCursor != null && fileCursor.moveToFirst()) {
        int cIndex = fileCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
        if (cIndex != -1) {
            fileName = fileCursor.getString(cIndex);
        }
    }
    return fileName;
}

$(...).datepicker is not a function - JQuery - Bootstrap

I resolved this by arranging the order in which your JS is being loaded.

You need to have it as jQuery -> datePicker -> Init js

Call your JQuery in your header, datePicker script in head below your jquery and Init JS in footer

How to pass command line argument to gnuplot?

The answer of Jari Laamanen is the best solution. I want just explain how to use more than 1 input parameter with shell variables:

output=test1.png
data=foo.data
gnuplot -e "datafile='${data}'; outputname='${output}'" foo.plg

and foo.plg:

set terminal png
set outputname 
f(x) = sin(x)
plot datafile

As you can see,more parameters are passed with semi colons (like in bash scripts), but string variables NEED to be encapsuled with ' ' (gnuplot syntax, NOT Bash syntax)

How to abort a Task like aborting a Thread (Thread.Abort method)?

using System;
using System.Threading;
using System.Threading.Tasks;

...

var cts = new CancellationTokenSource();
var task = Task.Run(() => { while (true) { } });
Parallel.Invoke(() =>
{
    task.Wait(cts.Token);
}, () =>
{
    Thread.Sleep(1000);
    cts.Cancel();
});

This is a simple snippet to abort a never-ending task with CancellationTokenSource.

Char to int conversion in C

Since the ASCII codes for '0','1','2'.... are placed from 48 to 57 they are essentially continuous. Now the arithmetic operations require conversion of char datatype to int datatype.Hence what you are basically doing is: 53-48 and hence it stores the value 5 with which you can do any integer operations.Note that while converting back from int to char the compiler gives no error but just performs a modulo 256 operation to put the value in its acceptable range

Explicitly set column value to null SQL Developer

You'll have to write the SQL DML yourself explicitly. i.e.

UPDATE <table>
   SET <column> = NULL;

Once it has completed you'll need to commit your updates

commit;

If you only want to set certain records to NULL use a WHERE clause in your UPDATE statement.

As your original question is pretty vague I hope this covers what you want.

How do I escape spaces in path for scp copy in Linux?

Sorry for using this Linux question to put this tip for Powershell on Windows 10: the space char escaping with backslashes or surrounding with quotes didn't work for me in this case. Not efficient, but I solved it using the "?" char instead:

for the file "tasks.txt Jun-22.bkp" I downloaded it using "tasks.txt?Jun-22.bkp"

How do you Sort a DataTable given column and direction?

DataTables have an overloaded Select method that you can you to do this. See here: http://msdn.microsoft.com/en-us/library/way3dy9w.aspx

But the return val of the Select call is not a DataTable but an array of RowData objects. If you want to return a DataTable from your function you will have to build it from scratch based on that data array. Here is a post that addresses and provides a sample for both issues: http://social.msdn.microsoft.com/Forums/en-US/winformsdatacontrols/thread/157a4a0f-1324-4301-9725-3def95de2bf2/

Sound effects in JavaScript / HTML5

You can always try AudioContext it has limited support but it's a part of the web audio api working draft. It might be worth it if you are planing to release something in the future. And if you are only programing for chrome and Firefox you're golden.