Programs & Examples On #Confidentiality

How do I keep CSS floats in one line?

Add this line to your floated element selector

.floated {
    float: left;
    ...
    box-sizing: border-box;
}

It will prevent padding and borders to be added to width, so element always stay in row, even if you have eg. three elements with width of 33.33333%

How do I return the response from an asynchronous call?

Originally, callback were used for asynchronous operations (e.g. in the XMLHttpRequest API). Now promise-based APIs like the browser's Fetch API have become the default solution and the nicer async/await syntax is supported by all modern browsers and on Node.Js (server side).

A common scenario - fetching JSON data from the server - can look like this:

async function fetchResource(url) {
  const res = await fetch(url);
  if (!res.ok) {
    throw new Error(res.statusText);
  }
  return res.json();
}

To use it in another function:

async function doSomething() {
  try {
    const data = await fetchResource("https://example.test/resource/1");
    // ...
  } catch (e) {
    // handle error
    ...
  }
}

If you design a modern API, it is strongly recommended to prefer promise-based style over callbacks. If you inherited an API that relies on callbacks, it is possible to wrap it as a promise:

function sleep(timeout) {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve();
    }, timeout);
  });
}

async function fetchAfterTwoSeconds(url) {
  await sleep(2000);
  return fetchResource(url);
}

In Node.Js, which historically relied exclusively on callbacks, that technique is so common that they added a helper function called util.promisify.

Hibernate Error: org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session

before the position where repetitive objects begin , you should close the session and then you should start a new session

session.close();      
session = HibernateUtil.getSessionFactory().openSession();

so in this way in one session there is not more than one entities that have the same identifier.

How to override maven property in command line?

See Introduction to the POM

finalName is created as:

<build>
    <finalName>${project.artifactId}-${project.version}</finalName>
</build>

One of the solutions is to add own property:

<properties>
    <finalName>${project.artifactId}-${project.version}</finalName>
</properties>
<build>
    <finalName>${finalName}</finalName>
 </build>

And now try:

mvn -DfinalName=build clean package

How can I enable "URL Rewrite" Module in IIS 8.5 in Server 2012?

Download it from here:

http://www.iis.net/downloads/microsoft/url-rewrite

or if you already have Web Platform Installer on your machine you can install it from there.

Run Excel Macro from Outside Excel Using VBScript From Command Line

Ok, it's actually simple. Assuming that your macro is in a module,not in one of the sheets, you use:

  objExcel.Application.Run "test.xls!dog" 
  'notice the format of 'workbook name'!macro

For a filename with spaces, encase the filename with quotes.

If you've placed the macro under a sheet, say sheet1, just assume sheet1 owns the function, which it does.

    objExcel.Application.Run "'test 2.xls'!sheet1.dog"

Notice: You don't need the macro.testfunction notation you've been using.

Change the maximum upload file size

Well, I would like to add my 2 cents here.

I'm using shared webhosting and I tackled this problem many times, tried to resolve it on my own but to no avail. Finally I managed to resolve it through checking various web sources and contacting my hosting service provider. My questions were "How can I change php value memory_limit in shared webhosting?", "How can I change php value upload_max_filesize in shared webhosting?", "How can I change php value max_input_vars in shared webhosting?", "How can I change php value max_execution_time in shared webhosting?", "How can I change php value max_input_time in shared webhosting?" and many more by configuring or changing php.ini or .htaccess file. I tried to change them but problems arose. Finally I contacted my hosting provider, and it turns out that I set my php to native, they changed it to php 5.6, here is their answer:

"Your PHP was set to 'native' mode which means you can't override those values. I've changed you to just '5.6' so you should be good to go."

After that I connected my website through ftp Filezilla, also don't forget to make both your ftp service to show hidden files, and your local computer to do so, because .htaccess file was hidden in my local laptop and in my website. It was available in public_html folder, I just downloaded it and added the following codes to the end of the file and then uploaded it back to the server:

php_value memory_limit 256M
php_value post_max_size 256M
php_value upload_max_filesize 64M
php_value max_input_vars 1800
php_value max_execution_time 300
php_value max_input_time 300

enter image description here

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enter image description here

enter image description here

enter image description here

Everything is working properly for the time being, if any of you overcome with some problems please write here and warn me so that I can change the above-shown codes. By the way, I also upload some pictures which shows the change.

One more thing I almost forgot to mention ZipArchive installation on your shared webhosting service, I managed that requirement to tick by just going to php settings through my cpanel, click on php selector extensions and then tick zip section, that's all.

Thanks.

PS: I'm open to good practices, and if you see any bad practice here please let me know, I'll try to change them. Thanks.

How to sort an array in descending order in Ruby

Simple Solution from ascending to descending and vice versa is:

STRINGS

str = ['ravi', 'aravind', 'joker', 'poker']
asc_string = str.sort # => ["aravind", "joker", "poker", "ravi"]
asc_string.reverse # => ["ravi", "poker", "joker", "aravind"]

DIGITS

digit = [234,45,1,5,78,45,34,9]
asc_digit = digit.sort # => [1, 5, 9, 34, 45, 45, 78, 234]
asc_digit.reverse # => [234, 78, 45, 45, 34, 9, 5, 1]

Numpy matrix to array

This will convert the matrix into array

A = np.ravel(M).T

How to get evaluated attributes inside a custom directive

For the same solution I was looking for Angularjs directive with ng-Model.
Here is the code that resolve the problem.

    myApp.directive('zipcodeformatter', function () {
    return {
        restrict: 'A', // only activate on element attribute
        require: '?ngModel', // get a hold of NgModelController
        link: function (scope, element, attrs, ngModel) {

            scope.$watch(attrs.ngModel, function (v) {
                if (v) {
                    console.log('value changed, new value is: ' + v + ' ' + v.length);
                    if (v.length > 5) {
                        var newzip = v.replace("-", '');
                        var str = newzip.substring(0, 5) + '-' + newzip.substring(5, newzip.length);
                        element.val(str);

                    } else {
                        element.val(v);
                    }

                }

            });

        }
    };
});


HTML DOM

<input maxlength="10" zipcodeformatter onkeypress="return isNumberKey(event)" placeholder="Zipcode" type="text" ng-readonly="!checked" name="zipcode" id="postal_code" class="form-control input-sm" ng-model="patient.shippingZipcode" required ng-required="true">


My Result is:

92108-2223

Cannot execute RUN mkdir in a Dockerfile

Apart from the previous use cases, you can also use Docker Compose to create directories in case you want to make new dummy folders on docker-compose up:

    volumes:
  - .:/ftp/
  - /ftp/node_modules
  - /ftp/files

Error in model.frame.default: variable lengths differ

Its simple, just make sure the data type in your columns are the same. For e.g. I faced the same error, that and an another error:

Error in contrasts<-(*tmp*, value = contr.funs[1 + isOF[nn]]) : contrasts can be applied only to factors with 2 or more levels

So, I went back to my excel file or csv file, set a filter on the variable throwing me an error and checked if the distinct datatypes are the same. And... Oh! it had numbers and strings, so I converted numbers to string and it worked just fine for me.

How to Select Columns in Editors (Atom,Notepad++, Kate, VIM, Sublime, Textpad,etc) and IDEs (NetBeans, IntelliJ IDEA, Eclipse, Visual Studio, etc)

Eclipse used to need a column mode plugin to be able to select a rectangular selection.

column mode

Since Eclipse 3.5, you just need to type Alt+Shift+A: see its News and Noteworthy section. (On OS X it's Option-Command-A.)

block (aka column or rectangular) selection mode

Or activate the 'Editor Presentation' action set ( Window > Customize Perspective menu) to get a tool bar button for toggling the block selection mode.

AmbroseChapel adds in the comments:

This is a toggle.

Columnar selection is a mode you enter and leave: in other words, Eclipse switches into a mode where all mouse selections have to be columnar and you stay in that mode until you switch back (by using the same command again).
It's not like other editors where columnar selections are enabled only while certain keys are down.

Question mark characters displaying within text, why is this?

I had this issue so I just took all my content, copy/pasted it into notepad, made a new php file, pasted back in, re-saved and overwrote, and.. that worked! It really was some relic of Microsoft Word editing...

Initialize value of 'var' in C# to null

var variables still have a type - and the compiler error message says this type must be established during the declaration.

The specific request (assigning an initial null value) can be done, but I don't recommend it. It doesn't provide an advantage here (as the type must still be specified) and it could be viewed as making the code less readable:

var x = (String)null;

Which is still "type inferred" and equivalent to:

String x = null;

The compiler will not accept var x = null because it doesn't associate the null with any type - not even Object. Using the above approach, var x = (Object)null would "work" although it is of questionable usefulness.

Generally, when I can't use var's type inference correctly then

  1. I am at a place where it's best to declare the variable explicitly; or
  2. I should rewrite the code such that a valid value (with an established type) is assigned during the declaration.

The second approach can be done by moving code into methods or functions.

Is it possible to append Series to rows of DataFrame without making a list first?

Try using this command. See the example given below:

Before image

df.loc[len(df)] = ['Product 9',99,9.99,8.88,1.11]

df

After Image

Why does an SSH remote command get fewer environment variables then when run manually?

I found an easy resolution for this issue was to add source /etc/profile to the top of the script.sh file I was trying to run on the target system. On the systems here, this caused the environmental variables which were needed by script.sh to be configured as if running from a login shell.

In one of the prior responses it was suggested that ~/.bashr_profile etc... be used. I didn't spend much time on this but, the problem with this is if you ssh to a different user on the target system than the shell on the source system from which you log in it appeared to me that this causes the source system user name to be used for the ~.

XPath OR operator for different nodes

If you want to select only one of two nodes with union operator, you can use this solution: (//bookstore/book/title | //bookstore/city/zipcode/title)[1]

Calculate execution time of a SQL query?

I found this one more helpful and simple

DECLARE @StartTime datetime,@EndTime datetime   
SELECT @StartTime=GETDATE() 
--Your Query to be run goes here--  
SELECT @EndTime=GETDATE()   
SELECT DATEDIFF(ms,@StartTime,@EndTime) AS [Duration in milliseconds]   

Updating and committing only a file's permissions using git version control

By default, git will update execute file permissions if you change them. It will not change or track any other permissions.

If you don't see any changes when modifying execute permission, you probably have a configuration in git which ignore file mode.

Look into your project, in the .git folder for the config file and you should see something like this:

[core]
    filemode = false

You can either change it to true in your favorite text editor, or run:

git config core.filemode true

Then, you should be able to commit normally your files. It will only commit the permission changes.

How to pass a form input value into a JavaScript function

Well ya you can do that in this way.

    <input type="text" name="address" id="address">
        <div id="map_canvas" style="width: 500px; height: 300px"></div>
    <input type="button" onclick="showAddress(address.value)" value="ShowMap"/>

Java Script

function showAddress(address){

    alert("This is address :"+address)

}

That is one example for the same. and that will run.

PHP regular expressions: No ending delimiter '^' found in

You can use T-Regx library, that doesn't need delimiters

pattern('^([0-9]+)$')->match($input);

PHP preg replace only allow numbers

Try this:

return preg_replace("/[^0-9]/", "",$c);

What is the largest TCP/IP network port number allowable for IPv4?

Valid numbers for ports are: 0 to 2^16-1 = 0 to 65535
That is because a port number is 16 bit length.

However ports are divided into:
Well-known ports: 0 to 1023 (used for system services e.g. HTTP, FTP, SSH, DHCP ...)
Registered/user ports: 1024 to 49151 (you can use it for your server, but be careful some famous applications: like Microsoft SQL Server database management system (MSSQL) server or Apache Derby Network Server are already taking from this range i.e. it is not recommended to assign the port of MSSQL to your server otherwise if MSSQL is running then your server most probably will not run because of port conflict )
Dynamic/private ports: 49152 to 65535. (not used for the servers rather the clients e.g. in NATing service)

In programming you can use any numbers 0 to 65535 for your server, however you should stick to the ranges mentioned above, otherwise some system services or some applications will not run because of port conflict.
Check the list of most ports here: https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

How do I find out if a column exists in a VB.Net DataRow

DataRow's are nice in the way that they have their underlying table linked to them. With the underlying table you can verify that a specific row has a specific column in it.

    If DataRow.Table.Columns.Contains("column") Then
        MsgBox("YAY")
    End If

How do I parse a string to a float or int?

To typecast in python use the constructor funtions of the type, passing the string (or whatever value you are trying to cast) as a parameter.

For example:

>>>float("23.333")
   23.333

Behind the scenes, python is calling the objects __float__ method, which should return a float representation of the parameter. This is especially powerful, as you can define your own types (using classes) with a __float__ method so that it can be casted into a float using float(myobject).

Auto-Submit Form using JavaScript

A simple solution for a delayed auto submit:

<body onload="setTimeout(function() { document.frm1.submit() }, 5000)">
   <form action="https://www.google.com" name="frm1">
      <input type="hidden" name="q" value="Hello world" />
   </form>
</body>

React proptype array with shape

If I am to define the same proptypes for a particular shape multiple times, I like abstract it out to a proptypes file so that if the shape of the object changes, I only have to change the code in one place. It helps dry up the codebase a bit.

Example:

// Inside my proptypes.js file
import PT from 'prop-types';

export const product = {
  id: PT.number.isRequired,
  title: PT.string.isRequired,
  sku: PT.string.isRequired,
  description: PT.string.isRequired,
};


// Inside my component file
import PT from 'prop-types';
import { product } from './proptypes;


List.propTypes = {
  productList: PT.arrayOf(product)
}

How to run shell script on host from docker container?

Write a simple server python server listening on a port (say 8080), bind the port -p 8080:8080 with the container, make a HTTP request to localhost:8080 to ask the python server running shell scripts with popen, run a curl or writing code to make a HTTP request curl -d '{"foo":"bar"}' localhost:8080

#!/usr/bin/python
from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer
import subprocess
import json

PORT_NUMBER = 8080

# This class will handles any incoming request from
# the browser 
class myHandler(BaseHTTPRequestHandler):
        def do_POST(self):
                content_len = int(self.headers.getheader('content-length'))
                post_body = self.rfile.read(content_len)
                self.send_response(200)
                self.end_headers()
                data = json.loads(post_body)

                # Use the post data
                cmd = "your shell cmd"
                p = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)
                p_status = p.wait()
                (output, err) = p.communicate()
                print "Command output : ", output
                print "Command exit status/return code : ", p_status

                self.wfile.write(cmd + "\n")
                return
try:
        # Create a web server and define the handler to manage the
        # incoming request
        server = HTTPServer(('', PORT_NUMBER), myHandler)
        print 'Started httpserver on port ' , PORT_NUMBER

        # Wait forever for incoming http requests
        server.serve_forever()

except KeyboardInterrupt:
        print '^C received, shutting down the web server'
        server.socket.close()

Alter a MySQL column to be AUTO_INCREMENT

Setting column as primary key and auto_increment at the same time:

  mysql> ALTER TABLE persons MODIFY COLUMN personID INT auto_increment PRIMARY KEY;
    Query OK, 10 rows affected (0.77 sec)
    Records: 10  Duplicates: 0  Warnings: 0

    mysql>

Python: SyntaxError: non-keyword after keyword arg

To really get this clear, here's my for-beginners answer: You inputed the arguments in the wrong order.
A keyword argument has this style:

nullable=True, unique=False

A fixed parameter should be defined: True, False, etc. A non-keyword argument is different:

name="Ricardo", fruit="chontaduro" 

This syntax error asks you to first put name="Ricardo" and all of its kind (non-keyword) before those like nullable=True.

sed whole word search and replace

On Mac OS X, neither of these regex syntaxes work inside sed for matching whole words

  • \bmyWord\b
  • \<myWord\>

Hear me now and believe me later, this ugly syntax is what you need to use:

  • /[[:<:]]myWord[[:>:]]/

So, for example, to replace mint with minty for whole words only:

  • sed "s/[[:<:]]mint[[:>:]]/minty/g"

Source: re_format man page

How to set user environment variables in Windows Server 2008 R2 as a normal user?

Under "Start" enter "environment" in the search field. That will list the option to change the system variables directly in the start menu.

Get time in milliseconds using C#

I used DateTime.Now.TimeOfDay.TotalMilliseconds (for current day), hope it helps you out as well.

How to get an HTML element's style values in javascript?

In jQuery, you can do alert($("#theid").css("width")).

-- if you haven't taken a look at jQuery, I highly recommend it; it makes many simple javascript tasks effortless.

Update

for the record, this post is 5 years old. The web has developed, moved on, etc. There are ways to do this with Plain Old Javascript, which is better.

Understanding MongoDB BSON Document size limit

Perhaps storing a blog post -> comments relation in a non-relational database is not really the best design.

You should probably store comments in a separate collection to blog posts anyway.

[edit]

See comments below for further discussion.

C++ [Error] no matching function for call to

You are trying to call DeckOfCards::shuffle with a deckOfCards parameter:

deckOfCards cardDeck; // create DeckOfCards object
cardDeck.shuffle(cardDeck); // shuffle the cards in the deck

But the method takes a vector<Card>&:

void deckOfCards::shuffle(vector<Card>& deck)

The compiler error messages are quite clear on this. I'll paraphrase the compiler as it talks to you.

Error:

[Error] no matching function for call to 'deckOfCards::shuffle(deckOfCards&)'

Paraphrased:

Hey, pal. You're trying to call a function called shuffle which apparently takes a single parameter of type reference-to-deckOfCards, but there is no such function.

Error:

[Note] candidate is:

In file included from main.cpp

[Note] void deckOfCards::shuffle(std::vector&)

Paraphrased:

I mean, maybe you meant this other function called shuffle, but that one takes a reference-tovector<something>.

Error:

[Note] no known conversion for argument 1 from 'deckOfCards' to 'std::vector&'

Which I'd be happy to call if I knew how to convert from a deckOfCards to a vector; but I don't. So I won't.

Twitter Bootstrap Tabs: Go to Specific Tab on Page Reload or Hyperlink

I am not a big fan of if...else; so I took a simpler approach.

$(document).ready(function(event) {
    $('ul.nav.nav-tabs a:first').tab('show'); // Select first tab
    $('ul.nav.nav-tabs a[href="'+ window.location.hash+ '"]').tab('show'); // Select tab by name if provided in location hash
    $('ul.nav.nav-tabs a[data-toggle="tab"]').on('shown', function (event) {    // Update the location hash to current tab
        window.location.hash= event.target.hash;
    })
});
  1. Pick a default tab (usually the first)
  2. Switch to tab (if such an element is indeed present; let jQuery handle it); Nothing happens if a wrong hash is specified
  3. [Optional] Update the hash if another tab is manually chosen

Doesn't address scrolling to requested hash; but should it?

Aligning rotated xticklabels with their respective xticks

You can set the horizontal alignment of ticklabels, see the example below. If you imagine a rectangular box around the rotated label, which side of the rectangle do you want to be aligned with the tickpoint?

Given your description, you want: ha='right'

n=5

x = np.arange(n)
y = np.sin(np.linspace(-3,3,n))
xlabels = ['Ticklabel %i' % i for i in range(n)]

fig, axs = plt.subplots(1,3, figsize=(12,3))

ha = ['right', 'center', 'left']

for n, ax in enumerate(axs):
    ax.plot(x,y, 'o-')
    ax.set_title(ha[n])
    ax.set_xticks(x)
    ax.set_xticklabels(xlabels, rotation=40, ha=ha[n])

enter image description here

Managing large binary files with Git

Have a look at git bup which is a Git extension to smartly store large binaries in a Git repository.

You'd want to have it as a submodule, but you won't have to worry about the repository getting hard to handle. One of their sample use cases is storing VM images in Git.

I haven't actually seen better compression rates, but my repositories don't have really large binaries in them.

Your mileage may vary.

What is the Git equivalent for revision number?

Each commit has a unique hash. Other than that there are no revision numbers in git. You'll have to tag commits yourself if you want more user-friendliness.

HTML5 Pre-resize images before uploading

Correction to above:

<img src="" id="image">
<input id="input" type="file" onchange="handleFiles()">
<script>

function handleFiles()
{
    var filesToUpload = document.getElementById('input').files;
    var file = filesToUpload[0];

    // Create an image
    var img = document.createElement("img");
    // Create a file reader
    var reader = new FileReader();
    // Set the image once loaded into file reader
    reader.onload = function(e)
    {
        img.src = e.target.result;

        var canvas = document.createElement("canvas");
        //var canvas = $("<canvas>", {"id":"testing"})[0];
        var ctx = canvas.getContext("2d");
        ctx.drawImage(img, 0, 0);

        var MAX_WIDTH = 400;
        var MAX_HEIGHT = 300;
        var width = img.width;
        var height = img.height;

        if (width > height) {
          if (width > MAX_WIDTH) {
            height *= MAX_WIDTH / width;
            width = MAX_WIDTH;
          }
        } else {
          if (height > MAX_HEIGHT) {
            width *= MAX_HEIGHT / height;
            height = MAX_HEIGHT;
          }
        }
        canvas.width = width;
        canvas.height = height;
        var ctx = canvas.getContext("2d");
        ctx.drawImage(img, 0, 0, width, height);

        var dataurl = canvas.toDataURL("image/png");
        document.getElementById('image').src = dataurl;     
    }
    // Load files into file reader
    reader.readAsDataURL(file);


    // Post the data
    /*
    var fd = new FormData();
    fd.append("name", "some_filename.jpg");
    fd.append("image", dataurl);
    fd.append("info", "lah_de_dah");
    */
}</script>

Can’t delete docker image with dependent child images

You should try to remove unnecessary images before removing the image:

docker rmi $(docker images --filter "dangling=true" -q --no-trunc)

After that, run:

docker rmi c565603bc87f

Set a button group's width to 100% and make buttons equal width?

There's no need for extra css the .btn-group-justified class does this.

You have to add this to the parent element and then wrap each btn element in a div with .btn-group like this

    <div class="form-group">

            <div class="btn-group btn-group-justified">
                <div class="btn-group">
                    <button type="submit" id="like" class="btn btn-lg btn-success ">Like</button>
                </div>
                <div class="btn-group">
                    <button type="submit" id="nope" class="btn btn-lg btn-danger ">Nope</button>
                </div>
            </div>

        </div>

Generating random numbers with normal distribution in Excel

IF you have excel 2007, you can use

=NORMSINV(RAND())*SD+MEAN

Because there was a big change in 2010 about excel's function

Lodash remove duplicates from array

For a simple array, you have the union approach, but you can also use :

_.uniq([2, 1, 2]);

relative path to CSS file

if the file containing that link tag is in the root dir of the project, then the correct path would be "css/styles.css"

Use ASP.NET MVC validation with jquery ajax?

Added some more logic to solution provided by @Andrew Burgess. Here is the full solution:

Created a action filter to get errors for ajax request:

public class ValidateAjaxAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            if (!filterContext.HttpContext.Request.IsAjaxRequest())
                return;

            var modelState = filterContext.Controller.ViewData.ModelState;
            if (!modelState.IsValid)
            {
                var errorModel =
                        from x in modelState.Keys
                        where modelState[x].Errors.Count > 0
                        select new
                        {
                            key = x,
                            errors = modelState[x].Errors.
                                                          Select(y => y.ErrorMessage).
                                                          ToArray()
                        };
                filterContext.Result = new JsonResult()
                {
                    Data = errorModel
                };
                filterContext.HttpContext.Response.StatusCode =
                                                      (int)HttpStatusCode.BadRequest;
            }
        }
    }

Added the filter to my controller method as:

[HttpPost]
// this line is important
[ValidateAjax]
public ActionResult AddUpdateData(MyModel model)
{
    return Json(new { status = (result == 1 ? true : false), message = message }, JsonRequestBehavior.AllowGet);
}

Added a common script for jquery validation:

function onAjaxFormError(data) {
    var form = this;
    var errorResponse = data.responseJSON;
    $.each(errorResponse, function (index, value) {
        // Element highlight
        var element = $(form).find('#' + value.key);
        element = element[0];
        highLightError(element, 'input-validation-error');

        // Error message
        var validationMessageElement = $('span[data-valmsg-for="' + value.key + '"]');
        validationMessageElement.removeClass('field-validation-valid');
        validationMessageElement.addClass('field-validation-error');
        validationMessageElement.text(value.errors[0]);
    });
}

$.validator.setDefaults({
            ignore: [],
            highlight: highLightError,
            unhighlight: unhighlightError
        });

var highLightError = function(element, errorClass) {
    element = $(element);
    element.addClass(errorClass);
}

var unhighLightError = function(element, errorClass) {
    element = $(element);
    element.removeClass(errorClass);
}

Finally added the error javascript method to my Ajax Begin form:

@model My.Model.MyModel
@using (Ajax.BeginForm("AddUpdateData", "Home", new AjaxOptions { HttpMethod = "POST", OnFailure="onAjaxFormError" }))
{
}

How to create a Java cron job

You can use TimerTask for Cronjobs.

Main.java

public class Main{
   public static void main(String[] args){

     Timer t = new Timer();
     MyTask mTask = new MyTask();
     // This task is scheduled to run every 10 seconds

     t.scheduleAtFixedRate(mTask, 0, 10000);
   }

}

MyTask.java

class MyTask extends TimerTask{

   public MyTask(){
     //Some stuffs
   }

   @Override
   public void run() {
     System.out.println("Hi see you after 10 seconds");
   }

}

Alternative You can also use ScheduledExecutorService.

CSS scale down image to fit in containing div, without specifing original size

You can use a background image to accomplish this;

From MDN - Background Size: Contain:

This keyword specifies that the background image should be scaled to be as large as possible while ensuring both its dimensions are less than or equal to the corresponding dimensions of the background positioning area.

Demo

CSS:

#im {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url("path/to/img");
    background-repeat: no-repeat;
    background-size: contain;
}

HTML:

<div id="wrapper">
    <div id="im">
    </div>
</div>

Maven: How to rename the war file for the project?

You can use the following in the web module that produces the war:

<build>
  <finalName>bird</finalName>
 . . .
</build>

This leads to a file called bird.war to be created when goal "war:war" is used.

Rails 4 - passing variable to partial

Don't use locals in Rails 4.2+

In Rails 4.2 I had to remove the locals part and just use size: 30 instead. Otherwise, it wouldn't pass the local variable correctly.

For example, use this:

<%= render @users, size: 30 %>

How do I assert my exception message with JUnit Test annotation?

You could use the @Rule annotation with ExpectedException, like this:

@Rule
public ExpectedException expectedEx = ExpectedException.none();

@Test
public void shouldThrowRuntimeExceptionWhenEmployeeIDisNull() throws Exception {
    expectedEx.expect(RuntimeException.class);
    expectedEx.expectMessage("Employee ID is null");

    // do something that should throw the exception...
    System.out.println("=======Starting Exception process=======");
    throw new NullPointerException("Employee ID is null");
}

Note that the example in the ExpectedException docs is (currently) wrong - there's no public constructor, so you have to use ExpectedException.none().

Browser Caching of CSS files

Your file will probably be cached - but it depends...

Different browsers have slightly different behaviors - most noticeably when dealing with ambiguous/limited caching headers emanating from the server. If you send a clear signal, the browsers obey, virtually all of the time.

The greatest variance by far, is in the default caching configuration of different web servers and application servers.

Some (e.g. Apache) are likely to serve known static file types with HTTP headers encouraging the browser to cache them, while other servers may send no-cache commands with every response - regardless of filetype.

...

So, first off, read some of the excellent HTTP caching tutorials out there. HTTP Caching & Cache-Busting for Content Publishers was a real eye opener for me :-)

Next install and fiddle around with Firebug and the Live HTTP Headers add-on , to find out which headers your server is actually sending.

Then read your web server docs to find out how to tweak them to perfection (or talk your sysadmin into doing it for you).

...

As to what happens when the browser is restarted, it depends on the browser and the user configuration.

As a rule of thumb, expect the browser to be more likely to check in with the server after each restart, to see if anything has changed (see If-Last-Modified and If-None-Match).

If you configure your server correctly, it should be able to return a super-short 304 Not Modified (costing very little bandwidth) and after that the browser will use the cache as normal.

WCFTestClient The HTTP request is unauthorized with client authentication scheme 'Anonymous'

I see this isn't answered yet, this is an exact quote from here:

WSHttpBinding will try and perform an internal negotiate at the SSP layer. In order for this to be successful, you will need to allow anonymous in IIS for the VDir. WCF will then by default perfrom an SPNEGO for window credentials. Allowing anonymous at IIS layer is not allowing anyone in, it is deferring to the WCF stack.

I found this via: http://fczaja.blogspot.com/2009/10/http-request-is-unauthorized-with.html

After googling: http://www.google.tt/#hl=en&source=hp&q=+The+HTTP+request+is+unauthorized+with+client+authentication+scheme+%27Anonymous

where to place CASE WHEN column IS NULL in this query

That looks like it might belong in the select statement:

SELECT id, col1, col2, col3, (CASE WHEN table3.col3 IS NULL THEN table2.col3 AS col4 ELSE table3.col3 as col4 END)
FROM table1
LEFT OUTER JOIN table2
ON table1.id = table2.id
LEFT OUTER JOIN table3
ON table1.id = table3.id

Excel VBA - Delete empty rows

How about

sub foo()
  dim r As Range, rows As Long, i As Long
  Set r = ActiveSheet.Range("A1:Z50")
  rows = r.rows.Count
  For i = rows To 1 Step (-1)
    If WorksheetFunction.CountA(r.rows(i)) = 0 Then r.rows(i).Delete
  Next
End Sub

Try this

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Range("A" & i & ":" & "Z" & i)
            Else
                Set DelRange = Union(DelRange, Range("A" & i & ":" & "Z" & i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

IF you want to delete the entire row then use this code

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Rows(i)
            Else
                Set DelRange = Union(DelRange, Rows(i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

Pip error: Microsoft Visual C++ 14.0 is required

I got this error when I tried to install pymssql even though Visual C++ 2015 (14.0) is installed in my system.

I resolved this error by downloading the .whl file of pymssql from here.

Once downloaded, it can be installed by the following command :

pip install python_package.whl

Hope this helps

ERROR 1044 (42000): Access denied for 'root' With All Privileges

If you get an error 1044 (42000) when you try to run SQL commands in MySQL (which installed along XAMPP server) cmd prompt, then here's the solution:

  1. Close your MySQL command prompt.

  2. Open your cmd prompt (from Start menu -> run -> cmd) which will show: C:\Users\User>_

  3. Go to MySQL.exe by Typing the following commands:

C:\Users\User>cd\ C:\>cd xampp C:\xampp>cd mysql C:\xxampp\mysql>cd bin C:\xampp\mysql\bin>mysql -u root

  1. Now try creating a new database by typing:

    mysql> create database employee;
    

    if it shows:

    Query OK, 1 row affected (0.00 sec)
    mysql>
    

    Then congrats ! You are good to go...

how do I give a div a responsive height

For the height of a div to be responsive, it must be inside a parent element with a defined height to derive it's relative height from.

If you set the height of the container holding the image and text box on the right, you can subsequently set the heights of its two children to be something like 75% and 25%.

However, this will get a bit tricky when the site layout gets narrower and things will get wonky. Try setting the padding on .contentBg to something like 5.5%.

My suggestion is to use Media Queries to tweak the padding at different screen sizes, then bump everything into a single column when appropriate.

Merging arrays with the same keys

 $A = array('a' => 1, 'b' => 2, 'c' => 3);
 $B = array('c' => 4, 'd'=> 5);
 $C = array_merge_recursive($A, $B);
 $aWhere = array();
 foreach ($C as $k=>$v) {

    if (is_array($v)) {
        $aWhere[] = $k . ' in ('.implode(', ',$v).')';
    }
    else {
        $aWhere[] = $k . ' = ' . $v;
    }
 }
 $where = implode(' AND ', $aWhere);
 echo $where;

How to obfuscate Python code effectively?

You can use the base64 module to encode strings to stop shoulder surfing, but it's not going to stop someone finding your code if they have access to your files.

You can then use the compile() function and the eval() function to execute your code once you've decoded it.

>>> import base64
>>> mycode = "print 'Hello World!'"
>>> secret = base64.b64encode(mycode)
>>> secret
'cHJpbnQgJ2hlbGxvIFdvcmxkICEn'
>>> mydecode = base64.b64decode(secret)
>>> eval(compile(mydecode,'<string>','exec'))
Hello World!

So if you have 30 lines of code you'll probably want to encrypt it doing something like this:

>>> f = open('myscript.py')
>>> encoded = base64.b64encode(f.read())

You'd then need to write a second script that does the compile() and eval() which would probably include the encoded script as a string literal encased in triple quotes. So it would look something like this:

import base64
myscript = """IyBUaGlzIGlzIGEgc2FtcGxlIFB5d
              GhvbiBzY3JpcHQKcHJpbnQgIkhlbG
              xvIiwKcHJpbnQgIldvcmxkISIK"""
eval(compile(base64.b64decode(myscript),'<string>','exec'))

How to find all duplicate from a List<string>?

Using LINQ, ofcourse. The below code would give you dictionary of item as string, and the count of each item in your sourc list.

var item2ItemCount = list.GroupBy(item => item).ToDictionary(x=>x.Key,x=>x.Count());

Global Git ignore

Although other answers are correct they are setting the global config value whereas there is a default git location for the global git ignore file:

*nix:

~/.config/git/ignore

Windows:

%USERPROFILE%\git\ignore

You may need to create git directory and ignore file but then you can put your global ignores into that file and that's it!

Source

Which file to place a pattern in depends on how the pattern is meant to be used.

…

  • Patterns which a user wants Git to ignore in all situations (e.g., backup or temporary files generated by the user’s editor of choice) generally go into a file specified by core.excludesFile in the user’s ~/.gitconfig. Its default value is $XDG_CONFIG_HOME/git/ignore. If $XDG_CONFIG_HOME is either not set or empty, $HOME/.config/git/ignore is used instead.

UIView touch event in controller

Updating @Crashalot's answer for Swift 3.x:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let currentPoint = touch.location(in: self)
        // do something with your currentPoint
    }
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let currentPoint = touch.location(in: self)
        // do something with your currentPoint
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let currentPoint = touch.location(in: self)
        // do something with your currentPoint
    }
}

How to use ternary operator in razor (specifically on HTML attributes)?

A simpler version, for easy eyes!

@(true?"yes":"no")

Get current url in Angular

other.component.ts

So final correct solution is :

import { Component, OnInit } from '@angular/core';
import { Location } from '@angular/common';
import { Router } from '@angular/router'; 

/* 'router' it must be in small case */

    @Component({
      selector: 'app-other',
      templateUrl: './other.component.html',
      styleUrls: ['./other.component.css']
    })

    export class OtherComponent implements OnInit {

        public href: string = "";
        url: string = "asdf";

        constructor(private router : Router) {} // make variable private so that it would be accessible through out the component

        ngOnInit() {
            this.href = this.router.url;
            console.log(this.router.url);
        }
    }

C++ auto keyword. Why is it magic?

auto was a keyword that C++ "inherited" from C that had been there nearly forever, but virtually never used because there were only two possible conditions: either it wasn't allowed, or else it was assumed by default.

The use of auto to mean a deduced type was new with C++11.

At the same time, auto x = initializer deduces the type of x from the type of initializer the same way as template type deduction works for function templates. Consider a function template like this:

template<class T>
int whatever(T t) { 
    // point A
};

At point A, a type has been assigned to T based on the value passed for the parameter to whatever. When you do auto x = initializer;, the same type deduction is used to determine the type for x from the type of initializer that's used to initialize it.

This means that most of the type deduction mechanics a compiler needs to implement auto were already present and used for templates on any compiler that even sort of attempted to implement C++98/03. As such, adding support for auto was apparently fairly easy for essentially all the compiler teams--it was added quite quickly, and there seem to have been few bugs related to it either.

When this answer was originally written (in 2011, before the ink was dry on the C++ 11 standard) auto was already quite portable. Nowadays, it's thoroughly portable among all the mainstream compilers. The only obvious reasons to avoid it would be if you need to write code that's compatible with a C compiler, or you have a specific need to target some niche compiler that you know doesn't support it (e.g., a few people still write code for MS-DOS using compilers from Borland, Watcom, etc., that haven't seen significant upgrades in decades). If you're using a reasonably current version of any of the mainstream compilers, there's no reason to avoid it at all though.

How do I format date value as yyyy-mm-dd using SSIS expression builder?

Looks like you created a separate question. I was answering your other question How to change flat file source using foreach loop container in an SSIS package? with the same answer. Anyway, here it is again.

Create two string data type variables namely DirPath and FilePath. Set the value C:\backup\ to the variable DirPath. Do not set any value to the variable FilePath.

Variables

Select the variable FilePath and select F4 to view the properties. Set the EvaluateAsExpression property to True and set the Expression property as @[User::DirPath] + "Source" + (DT_STR, 4, 1252) DATEPART("yy" , GETDATE()) + "-" + RIGHT("0" + (DT_STR, 2, 1252) DATEPART("mm" , GETDATE()), 2) + "-" + RIGHT("0" + (DT_STR, 2, 1252) DATEPART("dd" , GETDATE()), 2)

Expression

How to count the number of words in a sentence, ignoring numbers, punctuation and whitespace?

s = "I     am having  a   very  nice  23!@$      day. "
sum([i.strip(string.punctuation).isalpha() for i in s.split()])

The statement above will go through each chunk of text and remove punctuations before verifying if the chunk is really string of alphabets.

trying to animate a constraint in swift

It's very important to point out that view.layoutIfNeeded() applies to the view subviews only.

Therefore to animate the view constraint, it is important to call it on the view-to-animate superview as follows:

    topConstraint.constant = heightShift

    UIView.animate(withDuration: 0.3) {

        // request layout on the *superview*
        self.view.superview?.layoutIfNeeded()
    }

An example for a simple layout as follows:

class MyClass {

    /// Container view
    let container = UIView()
        /// View attached to container
        let view = UIView()

    /// Top constraint to animate
    var topConstraint = NSLayoutConstraint()


    /// Create the UI hierarchy and constraints
    func createUI() {
        container.addSubview(view)

        // Create the top constraint
        topConstraint = view.topAnchor.constraint(equalTo: container.topAnchor, constant: 0)


        view.translatesAutoresizingMaskIntoConstraints = false

        // Activate constaint(s)
        NSLayoutConstraint.activate([
           topConstraint,
        ])
    }

    /// Update view constraint with animation
    func updateConstraint(heightShift: CGFloat) {
        topConstraint.constant = heightShift

        UIView.animate(withDuration: 0.3) {

            // request layout on the *superview*
            self.view.superview?.layoutIfNeeded()
        }
    }
}

Increase distance between text and title on the y-axis

Based on this forum post: https://groups.google.com/forum/#!topic/ggplot2/mK9DR3dKIBU

Sounds like the easiest thing to do is to add a line break (\n) before your x axis, and after your y axis labels. Seems a lot easier (although dumber) than the solutions posted above.

ggplot(mpg, aes(cty, hwy)) + 
    geom_point() + 
    xlab("\nYour_x_Label") + ylab("Your_y_Label\n")

Hope that helps!

Best way to remove items from a collection

Here is a pretty good way to do it

http://support.microsoft.com/kb/555972

        System.Collections.ArrayList arr = new System.Collections.ArrayList();
        arr.Add("1");
        arr.Add("2");
        arr.Add("3");

        /*This throws an exception
        foreach (string s in arr)
        {
            arr.Remove(s);
        }
        */

        //where as this works correctly
        Console.WriteLine(arr.Count);
        foreach (string s in new System.Collections.ArrayList(arr)) 
        {
            arr.Remove(s);
        }
        Console.WriteLine(arr.Count);
        Console.ReadKey();

Using multiprocessing.Process with a maximum number of simultaneous processes

It might be most sensible to use multiprocessing.Pool which produces a pool of worker processes based on the max number of cores available on your system, and then basically feeds tasks in as the cores become available.

The example from the standard docs (http://docs.python.org/2/library/multiprocessing.html#using-a-pool-of-workers) shows that you can also manually set the number of cores:

from multiprocessing import Pool

def f(x):
    return x*x

if __name__ == '__main__':
    pool = Pool(processes=4)              # start 4 worker processes
    result = pool.apply_async(f, [10])    # evaluate "f(10)" asynchronously
    print result.get(timeout=1)           # prints "100" unless your computer is *very* slow
    print pool.map(f, range(10))          # prints "[0, 1, 4,..., 81]"

And it's also handy to know that there is the multiprocessing.cpu_count() method to count the number of cores on a given system, if needed in your code.

Edit: Here's some draft code that seems to work for your specific case:

import multiprocessing

def f(name):
    print 'hello', name

if __name__ == '__main__':
    pool = multiprocessing.Pool() #use all available cores, otherwise specify the number you want as an argument
    for i in xrange(0, 512):
        pool.apply_async(f, args=(i,))
    pool.close()
    pool.join()

Remove the last character from a string

You can use

substr(string $string, int $start, int[optional] $length=null);

See substr in the PHP documentation. It returns part of a string.

Retrieve data from a ReadableStream object?

Note that you can only read a stream once, so in some cases, you may need to clone the response in order to repeatedly read it:

fetch('example.json')
  .then(res=>res.clone().json())
  .then( json => console.log(json))

fetch('url_that_returns_text')
  .then(res=>res.clone().text())
  .then( text => console.log(text))

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.

Read a plain text file with php

<?php

$fh = fopen('filename.txt','r');
while ($line = fgets($fh)) {
  // <... Do your work with the line ...>
  // echo($line);
}
fclose($fh);
?>

This will give you a line by line read.. read the notes at php.net/fgets regarding the end of line issues with Macs.

SQL query to check if a name begins and ends with a vowel

select distinct(city) from STATION 
where lower(substr(city, -1)) in ('a','e','i','o','u') 
      and lower(substr(city, 1,1)) in ('a','e','i','o','u');

Google Maps API v3 adding an InfoWindow to each marker

Try this:

for (var i in tracks[racer_id].data.points) {
    values = tracks[racer_id].data.points[i];                
    point = new google.maps.LatLng(values.lat, values.lng);
    if (values.qst) {
        var marker = new google.maps.Marker({map: map, position: point, clickable: true});
        tracks[racer_id].markers[i] = marker;
        var info = new google.maps.InfoWindow({
            content: '<b>Speed:</b> ' + values.inst + ' knots'
        });
        tracks[racer_id].info[i] = info;
        google.maps.event.addListener(tracks[racer_id].markers[i], 'click', function() {
            tracks[racer_id].info[i].open(map, tracks[racer_id].markers[i]);
        });
    }
    track_coordinates.push(point);
    bd.extend(point);
}

Load JSON text into class object in c#

I recommend you to use JSON.NET. it is an open source library to serialize and deserialize your c# objects into json and Json objects into .net objects ...

Serialization Example:

Product product = new Product();
product.Name = "Apple";
product.Expiry = new DateTime(2008, 12, 28);
product.Price = 3.99M;
product.Sizes = new string[] { "Small", "Medium", "Large" };

string json = JsonConvert.SerializeObject(product);
//{
//  "Name": "Apple",
//  "Expiry": new Date(1230422400000),
//  "Price": 3.99,
//  "Sizes": [
//    "Small",
//    "Medium",
//    "Large"
//  ]
//}

Product deserializedProduct = JsonConvert.DeserializeObject<Product>(json);

Performance Comparison To Other JSON serializiation Techniques enter image description here

Android WebView not loading URL

Add Permission Internet permission in manifest.

as <uses-permission android:name="android.permission.INTERNET"/>

This code it working

  public class WebActivity extends Activity {
  WebView wv;

 String url="http://www.teluguoneradio.com/rssHostDescr.php?hostId=147";

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_web);
    wv=(WebView)findViewById(R.id.webUrl_WEB);



WebSettings webSettings = wv.getSettings();
    wv.getSettings().setLoadWithOverviewMode(true);
    wv.getSettings().setUseWideViewPort(true);
    wv.getSettings().setBuiltInZoomControls(true);
    wv.getSettings().setPluginState(PluginState.ON);


    wv.setWebViewClient(new myWebClient());

    wv.loadUrl(url);
}




public class myWebClient extends WebViewClient {
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        // TODO Auto-generated method stub
        super.onPageStarted(view, url, favicon);
    }

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        // TODO Auto-generated method stub

        view.loadUrl(url);
        return true;

    }
}

Nth max salary in Oracle

These queries will also work:

Workaround 1)

SELECT ename, sal 
FROM Emp e1 WHERE n-1 = (SELECT COUNT(DISTINCT sal) 
                         FROM Emp e2 WHERE e2.sal > e1.sal)

Workaround 2) using row_num function.

SELECT * 
FROM ( 
   SELECT e.*, ROW_NUMBER() OVER (ORDER BY sal DESC) rn FROM Emp e 
) WHERE rn = n;

Workaround 3 ) using rownum pseudocolumn

Select MAX(SAL) 
from (
   Select * 
   from (
      Select * 
      from EMP 
      order by SAL Desc
   ) where rownum <= n
)

Copying text to the clipboard using Java

This works for me and is quite simple:

Import these:

import java.awt.datatransfer.StringSelection;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;

And then put this snippet of code wherever you'd like to alter the clipboard:

String myString = "This text will be copied into clipboard";
StringSelection stringSelection = new StringSelection(myString);
Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
clipboard.setContents(stringSelection, null);

Using PHP to upload file and add the path to MySQL database

First you should use print_r($_FILES) to debug, and see what it contains. :

your uploads.php would look like:

//This is the directory where images will be saved
$target = "pics/";
$target = $target . basename( $_FILES['Filename']['name']);

//This gets all the other information from the form
$Filename=basename( $_FILES['Filename']['name']);
$Description=$_POST['Description'];


//Writes the Filename to the server
if(move_uploaded_file($_FILES['Filename']['tmp_name'], $target)) {
    //Tells you if its all ok
    echo "The file ". basename( $_FILES['Filename']['name']). " has been uploaded, and your information has been added to the directory";
    // Connects to your Database
    mysql_connect("localhost", "root", "") or die(mysql_error()) ;
    mysql_select_db("altabotanikk") or die(mysql_error()) ;

    //Writes the information to the database
    mysql_query("INSERT INTO picture (Filename,Description)
    VALUES ('$Filename', '$Description')") ;
} else {
    //Gives and error if its not
    echo "Sorry, there was a problem uploading your file.";
}



?>

EDIT: Since this is old post, currently it is strongly recommended to use either mysqli or pdo instead mysql_ functions in php

How do I setup the dotenv file in Node.js?

If you use "firebase-functions" to host your sever-side-rendered application, you should be aware of this one:

error: Error: ENOENT: no such file or directory, open 'C:\Codes\url_shortener\functions\.env'

Means you have to store the .env file in the functions folder as well.

Found this one by:

console.log(require('dotenv').config())

AngularJS - add HTML element to dom in directive without jQuery

Why not to try simple (but powerful) html() method:

iElement.html('<svg width="600" height="100" class="svg"></svg>');

Or append as an alternative:

iElement.append('<svg width="600" height="100" class="svg"></svg>');

And , of course , more cleaner way:

 var svg = angular.element('<svg width="600" height="100" class="svg"></svg>');
 iElement.append(svg);

Fiddle: http://jsfiddle.net/cherniv/AgGwK/

Instagram how to get my user id from username?

If you are using implicit Authentication must have the problem of not being able to find the user_id

I found a way for example:

Access Token = 1506417331.18b98f6.8a00c0d293624ded801d5c723a25d3ec the User id is 1506417331

would you do a split single seperated by . obtenies to acces token and the first element

How to print instances of a class using print()?

You need to use __repr__. This is a standard function like __init__. For example:

class Foobar():
    """This will create Foobar type object."""

    def __init__(self):
        print "Foobar object is created."

    def __repr__(self):
        return "Type what do you want to see here."

a = Foobar()

print a

Passing arguments to require (when loading module)

Yes. In your login module, just export a single function that takes the db as its argument. For example:

module.exports = function(db) {
  ...
};

Should you use rgba(0, 0, 0, 0) or rgba(255, 255, 255, 0) for transparency in CSS?

There are two ways of storing a color with alpha. The first is exactly as you see it, with each component as-is. The second is to use pre-multiplied alpha, where the color values are multiplied by the alpha after converting it to the range 0.0-1.0; this is done to make compositing easier. Ordinarily you shouldn't notice or care which way is implemented by any particular engine, but there are corner cases where you might, for example if you tried to increase the opacity of the color. If you use rgba(0, 0, 0, 0) you are less likely to to see a difference between the two approaches.

Is there a REAL performance difference between INT and VARCHAR primary keys?

At HauteLook, we changed many of our tables to use natural keys. We did experience a real-world increase in performance. As you mention, many of our queries now use less joins which makes the queries more performant. We will even use a composite primary key if it makes sense. That being said, some tables are just easier to work with if they have a surrogate key.

Also, if you are letting people write interfaces to your database, a surrogate key can be helpful. The 3rd party can rely on the fact that the surrogate key will change only in very rare circumstances.

How do I execute external program within C code in linux with arguments?

For a simple way, use system():

#include <stdlib.h>
...
int status = system("./foo 1 2 3");

system() will wait for foo to complete execution, then return a status variable which you can use to check e.g. exitcode (the command's exitcode gets multiplied by 256, so divide system()'s return value by that to get the actual exitcode: int exitcode = status / 256).

The manpage for wait() (in section 2, man 2 wait on your Linux system) lists the various macros you can use to examine the status, the most interesting ones would be WIFEXITED and WEXITSTATUS.

Alternatively, if you need to read foo's standard output, use popen(3), which returns a file pointer (FILE *); interacting with the command's standard input/output is then the same as reading from or writing to a file.

How do I spool to a CSV formatted file using SQLPLUS?

You should be aware that values of fields could contain commas and quotation characters, so some of the suggested answers would not work, as the CSV output file would not be correct. To replace quotation characters in a field, and replace it with the double quotation character, you can use the REPLACE function that oracle provides, to change a single quote to double quote.

set echo off
set heading off
set feedback off
set linesize 1024   -- or some other value, big enough
set pagesize 50000
set verify off
set trimspool on

spool output.csv
select trim(
       '"'   || replace(col1, '"', '""') || 
       '","' || replace(col2, '"', '""') ||
       '","' || replace(coln, '"', '""') || '"' ) -- etc. for all the columns
from   yourtable
/
spool off

Or, if you want the single quote character for the fields:

set echo off
set heading off
set feedback off
set linesize 1024   -- or some other value, big enough
set pagesize 50000
set verify off
set trimspool on

spool output.csv
select trim(
'"'   || replace(col1, '''', '''''') || 
'","' || replace(col2, '''', '''''') ||
'","' || replace(coln, '''', '''''') || '"' ) -- etc. for all the columns
from   yourtable
/
spool off

Combine two columns and add into one new column

Did you check the string concatenation function? Something like:

update table_c set column_a = column_b || column_c 

should work. More here

what is Ljava.lang.String;@

[ stands for single dimension array
Ljava.lang.String stands for the string class (L followed by class/interface name)

Few Examples:

  1. Class.forName("[D") -> Array of primitive double
  2. Class.forName("[[Ljava.lang.String") -> Two dimensional array of strings.

List of notations:
Element Type : Notation
boolean : Z
byte : B
char : C
class or interface : Lclassname
double : D
float : F
int : I
long : J
short : S

HTTP status code for update and delete?

{
    "VALIDATON_ERROR": {
        "code": 512,
        "message": "Validation error"
    },
    "CONTINUE": {
        "code": 100,
        "message": "Continue"
    },
    "SWITCHING_PROTOCOLS": {
        "code": 101,
        "message": "Switching Protocols"
    },
    "PROCESSING": {
        "code": 102,
        "message": "Processing"
    },
    "OK": {
        "code": 200,
        "message": "OK"
    },
    "CREATED": {
        "code": 201,
        "message": "Created"
    },
    "ACCEPTED": {
        "code": 202,
        "message": "Accepted"
    },
    "NON_AUTHORITATIVE_INFORMATION": {
        "code": 203,
        "message": "Non Authoritative Information"
    },
    "NO_CONTENT": {
        "code": 204,
        "message": "No Content"
    },
    "RESET_CONTENT": {
        "code": 205,
        "message": "Reset Content"
    },
    "PARTIAL_CONTENT": {
        "code": 206,
        "message": "Partial Content"
    },
    "MULTI_STATUS": {
        "code": 207,
        "message": "Multi-Status"
    },
    "MULTIPLE_CHOICES": {
        "code": 300,
        "message": "Multiple Choices"
    },
    "MOVED_PERMANENTLY": {
        "code": 301,
        "message": "Moved Permanently"
    },
    "MOVED_TEMPORARILY": {
        "code": 302,
        "message": "Moved Temporarily"
    },
    "SEE_OTHER": {
        "code": 303,
        "message": "See Other"
    },
    "NOT_MODIFIED": {
        "code": 304,
        "message": "Not Modified"
    },
    "USE_PROXY": {
        "code": 305,
        "message": "Use Proxy"
    },
    "TEMPORARY_REDIRECT": {
        "code": 307,
        "message": "Temporary Redirect"
    },
    "PERMANENT_REDIRECT": {
        "code": 308,
        "message": "Permanent Redirect"
    },
    "BAD_REQUEST": {
        "code": 400,
        "message": "Bad Request"
    },
    "UNAUTHORIZED": {
        "code": 401,
        "message": "Unauthorized"
    },
    "PAYMENT_REQUIRED": {
        "code": 402,
        "message": "Payment Required"
    },
    "FORBIDDEN": {
        "code": 403,
        "message": "Forbidden"
    },
    "NOT_FOUND": {
        "code": 404,
        "message": "Not Found"
    },
    "METHOD_NOT_ALLOWED": {
        "code": 405,
        "message": "Method Not Allowed"
    },
    "NOT_ACCEPTABLE": {
        "code": 406,
        "message": "Not Acceptable"
    },
    "PROXY_AUTHENTICATION_REQUIRED": {
        "code": 407,
        "message": "Proxy Authentication Required"
    },
    "REQUEST_TIMEOUT": {
        "code": 408,
        "message": "Request Timeout"
    },
    "CONFLICT": {
        "code": 409,
        "message": "Conflict"
    },
    "GONE": {
        "code": 410,
        "message": "Gone"
    },
    "LENGTH_REQUIRED": {
        "code": 411,
        "message": "Length Required"
    },
    "PRECONDITION_FAILED": {
        "code": 412,
        "message": "Precondition Failed"
    },
    "REQUEST_TOO_LONG": {
        "code": 413,
        "message": "Request Entity Too Large"
    },
    "REQUEST_URI_TOO_LONG": {
        "code": 414,
        "message": "Request-URI Too Long"
    },
    "UNSUPPORTED_MEDIA_TYPE": {
        "code": 415,
        "message": "Unsupported Media Type"
    },
    "REQUESTED_RANGE_NOT_SATISFIABLE": {
        "code": 416,
        "message": "Requested Range Not Satisfiable"
    },
    "EXPECTATION_FAILED": {
        "code": 417,
        "message": "Expectation Failed"
    },
    "IM_A_TEAPOT": {
        "code": 418,
        "message": "I'm a teapot"
    },
    "INSUFFICIENT_SPACE_ON_RESOURCE": {
        "code": 419,
        "message": "Insufficient Space on Resource"
    },
    "METHOD_FAILURE": {
        "code": 420,
        "message": "Method Failure"
    },
    "UNPROCESSABLE_ENTITY": {
        "code": 422,
        "message": "Unprocessable Entity"
    },
    "LOCKED": {
        "code": 423,
        "message": "Locked"
    },
    "FAILED_DEPENDENCY": {
        "code": 424,
        "message": "Failed Dependency"
    },
    "PRECONDITION_REQUIRED": {
        "code": 428,
        "message": "Precondition Required"
    },
    "TOO_MANY_REQUESTS": {
        "code": 429,
        "message": "Too Many Requests"
    },
    "REQUEST_HEADER_FIELDS_TOO_LARGE": {
        "code": 431,
        "message": "Request Header Fields Too"
    },
    "UNAVAILABLE_FOR_LEGAL_REASONS": {
        "code": 451,
        "message": "Unavailable For Legal Reasons"
    },
    "INTERNAL_SERVER_ERROR": {
        "code": 500,
        "message": "Internal Server Error"
    },
    "NOT_IMPLEMENTED": {
        "code": 501,
        "message": "Not Implemented"
    },
    "BAD_GATEWAY": {
        "code": 502,
        "message": "Bad Gateway"
    },
    "SERVICE_UNAVAILABLE": {
        "code": 503,
        "message": "Service Unavailable"
    },
    "GATEWAY_TIMEOUT": {
        "code": 504,
        "message": "Gateway Timeout"
    },
    "HTTP_VERSION_NOT_SUPPORTED": {
        "code": 505,
        "message": "HTTP Version Not Supported"
    },
    "INSUFFICIENT_STORAGE": {
        "code": 507,
        "message": "Insufficient Storage"
    },
    "NETWORK_AUTHENTICATION_REQUIRED": {
        "code": 511,
        "message": "Network Authentication Required"
    }
}

fatal: The current branch master has no upstream branch

For me, I was pushing the changes to a private repo to which I didn't had the write access. Make sure you have the valid access rights while performing push or pull operations.

You can directly verify via

How do I use su to execute the rest of the bash script as that user?

Use a script like the following to execute the rest or part of the script under another user:

#!/bin/sh

id

exec sudo -u transmission /bin/sh - << eof

id

eof

How to trigger ngClick programmatically

You can do like

$timeout(function() {
   angular.element('#btn2').triggerHandler('click');
});

Generate random string/characters in JavaScript

Improved @Andrew's answer above :

Array.from({ length : 1 }, () => Math.random().toString(36)[2]).join('');

Base 36 conversion of the random number is inconsistent, so selecting a single indice fixes that. You can change the length for a string with the exact length desired.

Javascript ES6 export const vs export let

I think that once you've imported it, the behaviour is the same (in the place your variable will be used outside source file).

The only difference would be if you try to reassign it before the end of this very file.

Numpy - add row to array

You can also do this:

newrow = [1,2,3]
A = numpy.concatenate((A,newrow))

Find all zero-byte files in directory and subdirectories

No, you don't have to bother grep.

find $dir -size 0 ! -name "*.xml"

How to pass variable from jade template file to a script file?

In my case, I was attempting to pass an object into a template via an express route (akin to OPs setup). Then I wanted to pass that object into a function I was calling via a script tag in a pug template. Though lagginreflex's answer got me close, I ended up with the following:

script.
    var data = JSON.parse('!{JSON.stringify(routeObj)}');
    funcName(data)

This ensured the object was passed in as expected, rather than needing to deserialise in the function. Also, the other answers seemed to work fine with primitives, but when arrays etc. were passed along with the object they were parsed as string values.

How to get 'System.Web.Http, Version=5.2.3.0?

One way to fix it is by modifying the assembly redirect in the web.config file.

Modify the following:

<dependentAssembly>
        <assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
</dependentAssembly>

to

<dependentAssembly>
        <assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="4.0.0.0" />
</dependentAssembly>

So the oldVersion attribute should change from "...-4.0.0.0" to "...-5.2.3.0".

Showing which files have changed between two revisions

If anyone is trying to generate a diff file from two branches :

git diff master..otherbranch > myDiffFile.diff

Float vs Decimal in ActiveRecord

In Rails 4.1.0, I have faced problem with saving latitude and longitude to MySql database. It can't save large fraction number with float data type. And I change the data type to decimal and working for me.

  def change
    change_column :cities, :latitude, :decimal, :precision => 15, :scale => 13
    change_column :cities, :longitude, :decimal, :precision => 15, :scale => 13
  end

Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?

@article = user.articles.build(:title => "MainTitle")
@article.save

Count number of occurrences for each unique value

You should change the query to:

SELECT time_col, COUNT(time_col) As Count
FROM time_table
WHERE activity_col = 3
GROUP BY time_col

This vl works correctly.

Differences between strong and weak in Objective-C

A dummy answer :-

I think explanation is given in above answer, so i am just gonna tell you where to use STRONG and where to use WEAK :

Use of Weak :- 1. Delegates 2. Outlets 3. Subviews 4. Controls, etc.

Use of Strong :- Remaining everywhere which is not included in WEAK.

HTTP test server accepting GET/POST requests

If you need or want a simple HTTP server with the following:

  • Can be run locally or in a network sealed from the public Internet
  • Has some basic auth
  • Handles POST requests

I built one on top of the excellent SimpleHTTPAuthServer already on PyPI. This adds handling of POST requests: https://github.com/arielampol/SimpleHTTPAuthServerWithPOST

Otherwise, all the other options publicly available are already so good and robust.

Emulator: ERROR: x86 emulation currently requires hardware acceleration

I wasted too much time on this, I find that the AVAST is the issue!!! If you have AVAST installed in you system, you have to:

Go to settings tab --> troubleshooting, then you should UNCHECK the "enable hardware-assisted virtualization"

Restart your PC, the install the intelhaxm-android.exe if it is not installed. You can find it:

C:\Users\{YOURUSERNAME}\AppData\Local\Android\sdk\extras\intel\Hardware_Accelerated_Execution_Manager

What is sys.maxint in Python 3?

An alternative is

import math

... math.inf ...

Access a URL and read Data with R

Beside of read.csv(url("...")) you also can use read.table("http://...").

Example:

> sample <- read.table("http://www.ats.ucla.edu/stat/examples/ara/angell.txt")
> sample
                V1   V2   V3   V4 V5
1        Rochester 19.0 20.6 15.0  E
2         Syracuse 17.0 15.6 20.2  E
...
43         Atlanta  4.2 70.6 32.6  S
> 

Click in OK button inside an Alert (Selenium IDE)

Use chooseOkOnNextConfirmation() to dismiss the alert and getAlert() to verify that it has been shown (and optionally grab its text for verification).

selenium.chooseOkOnNextConfirmation();  // prepares Selenium to handle next alert
selenium.click(locator);
String alertText = selenium.getAlert(); // verifies that alert was shown
assertEquals("This is a popup window", alertText);
...

Seaborn Barplot - Displaying Values

A simple way to do so is to add the below code (for Seaborn):

for p in splot.patches:
    splot.annotate(format(p.get_height(), '.1f'), 
                   (p.get_x() + p.get_width() / 2., p.get_height()), 
                   ha = 'center', va = 'center', 
                   xytext = (0, 9), 
                   textcoords = 'offset points') 

Example :

splot = sns.barplot(df['X'], df['Y'])
# Annotate the bars in plot
for p in splot.patches:
    splot.annotate(format(p.get_height(), '.1f'), 
                   (p.get_x() + p.get_width() / 2., p.get_height()), 
                   ha = 'center', va = 'center', 
                   xytext = (0, 9), 
                   textcoords = 'offset points')    
plt.show()

Sound effects in JavaScript / HTML5

It's not possible to do multi-shot playing with a single <audio> element. You need to use multiple elements for this.

Change the selected value of a drop-down list with jQuery

jQuery's documentation states:

[jQuery.val] checks, or selects, all the radio buttons, checkboxes, and select options that match the set of values.

This behavior is in jQuery versions 1.2 and above.

You most likely want this:

$("._statusDDL").val('2');

Jquery - Uncaught TypeError: Cannot use 'in' operator to search for '324' in

In my case, I forgot to tell the type controller that the response is a JSON object. response.setContentType("application/json");

Get single listView SelectedItem

Usually SelectedItems returns either a collection, an array or an IQueryable.

Either way you can access items via the index as with an array:

String text = listView1.SelectedItems[0].Text; 

By the way, you can save an item you want to look at into a variable, and check its structure in the locals after setting a breakpoint.

Where to find htdocs in XAMPP Mac

Make sure no other apache servers are running as it generates an error when you try to access it on the browser even with a different port. Go to Finder and below Device you will usually see the lampp icon. You can also open the htdocs from any of the ide or code editor by opening files or project once you locate the lampp icon. Make sure you mount the stack.

PHP, display image with Header()

Browsers can often tell the image type by sniffing out the meta information of the image. Also, there should be a space in that header:

header('Content-type: image/png');

Simulating Button click in javascript

Use this

jQuery("input.second").trigger("click");

How to turn off the Eclipse code formatter for certain sections of Java code?

@xpmatteo has the answer to disabling portions of code, but in addition to this, the default eclipse settings should be set to only format edited lines of code instead of the whole file.

Preferences->Java->Editor->Save Actions->Format Source Code->Format Edited Lines

This would have prevented it from happening in the first place since your coworkers are reformatting code they didn't actually change. This is a good practice to prevent mishaps that render diff on your source control useless (when an entire file is reformatted because of minor format setting differences).

It would also prevent the reformatting if the on/off tags option was turned off.

How can I pass arguments to a batch file?

Yep, and just don't forget to use variables like %%1 when using if and for and the gang.

If you forget the double %, then you will be substituting in (possibly null) command line arguments and you will receive some pretty confusing error messages.

Android: Background Image Size (in Pixel) which Support All Devices

Android Devices Matrices

                            ldpi     mdpi     hdpi    xhdpi    xxhdpi      xxxhdpi
Launcher And Home           36*36    48*48   72*72    96*96    144*144     192*192
Toolbar And Tab             24*24    32*32   48*48    64*64    96*96       128*128
Notification                18*18    24*24   36*36    48*48    72*72       96*96 
Background                 240*320  320*480 480*800  768*1280  1080 *1920  1440*2560 

(For good approach minus Toolbar Size From total height of Background Screen and then Design Graphics of Screens )

For More Help (This link includes tablets also):

https://design.google.com/devices/

Android Native Icons (Recommended) You can change color of these icons programmatically. https://design.google.com/icons/

How to convert <font size="10"> to px?

This cannot be answered that easily. It depends on the font used and the points per inch (ppi). This should give an overview of the problem.

Replacing column values in a pandas DataFrame

You can also use apply with .get i.e.

w['female'] = w['female'].apply({'male':0, 'female':1}.get):

w = pd.DataFrame({'female':['female','male','female']})
print(w)

Dataframe w:

   female
0  female
1    male
2  female

Using apply to replace values from the dictionary:

w['female'] = w['female'].apply({'male':0, 'female':1}.get)
print(w)

Result:

   female
0       1
1       0
2       1 

Note: apply with dictionary should be used if all the possible values of the columns in the dataframe are defined in the dictionary else, it will have empty for those not defined in dictionary.

check if a number already exist in a list in python

You could probably use a set object instead. Just add numbers to the set. They inherently do not replicate.

How can I output the value of an enum class in C++11

Following worked for me in C++11:

template <typename Enum>
constexpr typename std::enable_if<std::is_enum<Enum>::value,
                                  typename std::underlying_type<Enum>::type>::type
to_integral(Enum const& value) {
    return static_cast<typename std::underlying_type<Enum>::type>(value);
}

Can grep show only words that match search pattern?

You could pipe your grep output into Perl like this:

grep "th" * | perl -n -e'while(/(\w*th\w*)/g) {print "$1\n"}'

How do I link object files in C? Fails with "Undefined symbols for architecture x86_64"

The existing answers already cover the "how", but I just wanted to elaborate on the "what" and "why" for others who might be wondering.

What a compiler (gcc) does: The term "compile" is a bit of an overloaded term because it is used at a high-level to mean "convert source code to a program", but more technically means to "convert source code to object code". A compiler like gcc actually performs two related, but arguably distinct functions to turn your source code into a program: compiling (as in the latter definition of turning source to object code) and linking (the process of combining the necessary object code files together into one complete executable).

The original error that you saw is technically a "linking error", and is thrown by "ld", the linker. Unlike (strict) compile-time errors, there is no reference to source code lines, as the linker is already in object space.

By default, when gcc is given source code as input, it attempts to compile each and then link them all together. As noted in the other responses, it's possible to use flags to instruct gcc to just compile first, then use the object files later to link in a separate step. This two-step process may seem unnecessary (and probably is for very small programs) but it is very important when managing a very large program, where compiling the entire project each time you make a small change would waste a considerable amount of time.

Get the latest record with filter in Django

obj= Model.objects.filter(testfield=12).order_by('-id')[0]

CSS: create white glow around image

Use simple CSS3 (not supported in IE<9)

img
{
    box-shadow: 0px 0px 5px #fff;
}

This will put a white glow around every image in your document, use more specific selectors to choose which images you'd like the glow around. You can change the color of course :)

If you're worried about the users that don't have the latest versions of their browsers, use this:

img
{
-moz-box-shadow: 0 0 5px #fff;
-webkit-box-shadow: 0 0 5px #fff;
box-shadow: 0px 0px 5px #fff;
}

For IE you can use a glow filter (not sure which browsers support it)

img
{
    filter:progid:DXImageTransform.Microsoft.Glow(Color=white,Strength=5);
}

Play with the settings to see what suits you :)

Use CASE statement to check if column exists in table - SQL Server

Try this one -

SELECT *
FROM ...
WHERE EXISTS(SELECT 1 
        FROM sys.columns c
        WHERE c.[object_id] = OBJECT_ID('dbo.Tags')
            AND c.name = 'ModifiedByUser'
    )

How to generate class diagram from project in Visual Studio 2013?

Right click on the project in solution explorer or class view window --> "View" --> "View Class Diagram"

How to display and hide a div with CSS?

Html Code :

    <a id="f">Show First content!</a>
    <br/>
    <a id="s">Show Second content!!</a>
    <div class="a">Default Content</div>
    <div class="ab hideDiv">First content</div>
    <div class="abc hideDiv">Second content</div>

Script code:

$(document).ready(function() {
    $("#f").mouseover(function(){
        $('.a,.abc').addClass('hideDiv');
        $('.ab').removeClass('hideDiv');
    }).mouseout(function() {
        $('.a').removeClass('hideDiv');
        $('.ab,.abc').addClass('hideDiv');
    });

    $("#s").mouseover(function(){
        $('.a,.ab').addClass('hideDiv');
        $('.abc').removeClass('hideDiv');
    }).mouseout(function() {
        $('.a').removeClass('hideDiv');
        $('.ab,.abc').addClass('hideDiv');
    });
});

css code:

.hideDiv
{
    display:none;
}

'tuple' object does not support item assignment

You have misspelt the second pixels as pixel. The following works:

pixels = [1,2,3]
pixels[0] = 5

It appears that due to the typo you were trying to accidentally modify some tuple called pixel, and in Python tuples are immutable. Hence the confusing error message.

npm check and update package if needed

npm outdated will identify packages that should be updated, and npm update <package name> can be used to update each package. But prior to [email protected], npm update <package name> will not update the versions in your package.json which is an issue.

The best workflow is to:

  1. Identify out of date packages
  2. Update the versions in your package.json
  3. Run npm update to install the latest versions of each package

Check out npm-check-updates to help with this workflow.

  • Install npm-check-updates
  • Run npm-check-updates to list what packages are out of date (basically the same thing as running npm outdated)
  • Run npm-check-updates -u to update all the versions in your package.json (this is the magic sauce)
  • Run npm update as usual to install the new versions of your packages based on the updated package.json

React passing parameter via onclick event using ES6 syntax

I use the following code:

<Button onClick={this.onSubmit} id={item.key} value={shop.ethereum}>
    Approve
</Button>

Then inside the method:

onSubmit = async event => {
    event.preventDefault();
    event.persist();
    console.log("Param passed => Eth addrs: ", event.target.value)
    console.log("Param passed => id: ", event.target.id)
    ...
}

As a result:

Param passed in event => Eth addrs: 0x4D86c35fdC080Ce449E89C6BC058E6cc4a4D49A6

Param passed in event => id: Mlz4OTBSwcgPLBzVZ7BQbwVjGip1

Adding items to an object through the .push() method

Another way of doing it would be:

stuff = Object.assign(stuff, {$(this).attr('value'):$(this).attr('checked')});

Read more here: Object.assign()

Link to a section of a webpage

The fragment identifier (also known as: Fragment IDs, Anchor Identifiers, Named Anchors) introduced by a hash mark # is the optional last part of a URL for a document. It is typically used to identify a portion of that document.

<a href="http://www.someuri.com/page#fragment">Link to fragment identifier</a>

Syntax for URIs also allows an optional query part introduced by a question mark ?. In URIs with a query and a fragment the fragment follows the query.

<a href="http://www.someuri.com/page?query=1#fragment">Link to fragment with a query</a>

When a Web browser requests a resource from a Web server, the agent sends the URI to the server, but does not send the fragment. Instead, the agent waits for the server to send the resource, and then the agent (Web browser) processes the resource according to the document type and fragment value.

Named Anchors <a name="fragment"> are deprecated in XHTML 1.0, the ID attribute is the suggested replacement. <div id="fragment"></div>

Difference between Eclipse Europa, Helios, Galileo

Each version has some improvements in certain technologies. For users the biggest difference is whether or not to execute certain plugins, because some were made only for a particular version of Eclipse.

Converting from IEnumerable to List

I use an extension method for this. My extension method first checks to see if the enumeration is null and if so creates an empty list. This allows you to do a foreach on it without explicitly having to check for null.

Here is a very contrived example:

IEnumerable<string> stringEnumerable = null;
StringBuilder csv = new StringBuilder();
stringEnumerable.ToNonNullList().ForEach(str=> csv.Append(str).Append(","));

Here is the extension method:

public static List<T> ToNonNullList<T>(this IEnumerable<T> obj)
{
    return obj == null ? new List<T>() : obj.ToList();
}

How to copy folders to docker image from Dockerfile?

Replace the * with a /

So instead of

COPY * <destination>

use

COPY / <destination>

How can I convert a std::string to int?

Admittedly, my solution wouldn't work for negative integers, but it will extract all positive integers from input text containing integers. It makes use of numeric_only locale:

int main() {
        int num;
        std::cin.imbue(std::locale(std::locale(), new numeric_only()));
        while ( std::cin >> num)
             std::cout << num << std::endl;
        return 0;
}

Input text:

 the format (-5) or (25) etc... some text.. and then.. 7987...78hjh.hhjg9878

Output integers:

 5
25
7987
78
9878

The class numeric_only is defined as:

struct numeric_only: std::ctype<char> 
{
    numeric_only(): std::ctype<char>(get_table()) {}

    static std::ctype_base::mask const* get_table()
    {
        static std::vector<std::ctype_base::mask> 
            rc(std::ctype<char>::table_size,std::ctype_base::space);

        std::fill(&rc['0'], &rc[':'], std::ctype_base::digit);
        return &rc[0];
    }
};

Complete online demo : http://ideone.com/dRWSj

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

To get around the html vs body issue, I fixed this by not animating the css directly but rather calling window.scrollTo(); on each step:

$({myScrollTop:window.pageYOffset}).animate({myScrollTop:300}, {
  duration: 600,
  easing: 'swing',
  step: function(val) {
    window.scrollTo(0, val);
  }
});

This works nicely without any refresh gotchas as it's using cross-browser JavaScript.

Have a look at http://james.padolsey.com/javascript/fun-with-jquerys-animate/ for more information on what you can do with jQuery's animate function.

How can we convert an integer to string in AngularJs

.toString() is available, or just add "" to the end of the int

var x = 3,
    toString = x.toString(),
    toConcat = x + "";

Angular is simply JavaScript at the core.

TypeError: sequence item 0: expected string, int found

string.join connects elements inside list of strings, not ints.

Use this generator expression instead :

values = ','.join(str(v) for v in value_list)

Regex number between 1 and 100

Try:

^[1-9][0-9]?$|^100$

Working fiddle

EDIT: IF you want to match 00001, 00000099 try

^0*(?:[1-9][0-9]?|100)$

FIDDLE

Use of Application.DoEvents()

Hmya, the enduring mystique of DoEvents(). There's been an enormous amount of backlash against it, but nobody ever really explains why it is "bad". The same kind of wisdom as "don't mutate a struct". Erm, why does the runtime and the language supports mutating a struct if that's so bad? Same reason: you shoot yourself in the foot if you don't do it right. Easily. And doing it right requires knowing exactly what it does, which in the case of DoEvents() is definitely not easy to grok.

Right off the bat: almost any Windows Forms program actually contains a call to DoEvents(). It is cleverly disguised, however with a different name: ShowDialog(). It is DoEvents() that allows a dialog to be modal without it freezing the rest of the windows in the application.

Most programmers want to use DoEvents to stop their user interface from freezing when they write their own modal loop. It certainly does that; it dispatches Windows messages and gets any paint requests delivered. The problem however is that it isn't selective. It not only dispatches paint messages, it delivers everything else as well.

And there's a set of notifications that cause trouble. They come from about 3 feet in front of the monitor. The user could for example close the main window while the loop that calls DoEvents() is running. That works, user interface is gone. But your code didn't stop, it is still executing the loop. That's bad. Very, very bad.

There's more: The user could click the same menu item or button that causes the same loop to get started. Now you have two nested loops executing DoEvents(), the previous loop is suspended and the new loop is starting from scratch. That could work, but boy the odds are slim. Especially when the nested loop ends and the suspended one resumes, trying to finish a job that was already completed. If that doesn't bomb with an exception then surely the data is scrambled all to hell.

Back to ShowDialog(). It executes DoEvents(), but do note that it does something else. It disables all the windows in the application, other than the dialog. Now that 3-feet problem is solved, the user cannot do anything to mess up the logic. Both the close-the-window and start-the-job-again failure modes are solved. Or to put it another way, there is no way for the user to make your program run code in a different order. It will execute predictably, just like it did when you tested your code. It makes dialogs extremely annoying; who doesn't hate having a dialog active and not being able to copy and paste something from another window? But that's the price.

Which is what it takes to use DoEvents safely in your code. Setting the Enabled property of all your forms to false is a quick and efficient way to avoid problems. Of course, no programmer ever actually likes doing this. And doesn't. Which is why you shouldn't use DoEvents(). You should use threads. Even though they hand you a complete arsenal of ways to shoot your foot in colorful and inscrutable ways. But with the advantage that you only shoot your own foot; it won't (typically) let the user shoot hers.

The next versions of C# and VB.NET will provide a different gun with the new await and async keywords. Inspired in small part by the trouble caused by DoEvents and threads but in large part by WinRT's API design that requires you to keep your UI updated while an asynchronous operation is taking place. Like reading from a file.

Import JSON file in React

One nice way (without adding a fake .js extension which is for code not for data and configs) is to use json-loader module. If you have used create-react-app to scaffold your project, the module is already included, you just need to import your json:

import Profile from './components/profile';

This answer explains more.

How do I delete a local repository in git?

That's right, if you're on a mac(unix) you won't see .git in finder(the file browser). You can follow the directions above to delete and there are git commands that allow you to delete files as well(they are sometimes difficult to work with and learn, for example: on making a 'git rm -r ' command you might be prompted with a .git/ not found. Here is the git command specs:

usage: git rm [options] [--] ...

-n, --dry-run         dry run
-q, --quiet           do not list removed files
--cached              only remove from the index
-f, --force           override the up-to-date check
-r                    allow recursive removal
--ignore-unmatch      exit with a zero status even if nothing matched

When I had to do this, deleting the objects and refs didn't matter. After I deleted the other files in the .git, I initialized a git repo with 'git init' and it created an empty repo.

Integrating Dropzone.js into existing HTML form with other fields

Enyo's tutorial is excellent.

I found that the sample script in the tutorial worked well for a button embedded in the dropzone (i.e., the form element). If you wish to have the button outside the form element, I was able to accomplish it using a click event:

First, the HTML:

<form id="my-awesome-dropzone" action="/upload" class="dropzone">  
    <div class="dropzone-previews"></div>
    <div class="fallback"> <!-- this is the fallback if JS isn't working -->
        <input name="file" type="file" multiple />
    </div>

</form>
<button type="submit" id="submit-all" class="btn btn-primary btn-xs">Upload the file</button>

Then, the script tag....

Dropzone.options.myAwesomeDropzone = { // The camelized version of the ID of the form element

    // The configuration we've talked about above
    autoProcessQueue: false,
    uploadMultiple: true,
    parallelUploads: 25,
    maxFiles: 25,

    // The setting up of the dropzone
    init: function() {
        var myDropzone = this;

        // Here's the change from enyo's tutorial...

        $("#submit-all").click(function (e) {
            e.preventDefault();
            e.stopPropagation();
            myDropzone.processQueue();
        }); 
    }
}

Add / Change parameter of URL and redirect to the new URL

I had a similar situation where I wanted to replace a URL query parameter. However, I only had one param, and I could simply replace it:

window.location.search = '?filter=' + my_filter_value

The location.search property allows you to get or set the query portion of a URL.

How to change the blue highlight color of a UITableViewCell?

UITableViewCell has three default selection styles:-

  1. Blue
  2. Gray
  3. None

Implementation is as follows:-

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *) indexPath {

     [cell setSelectionStyle:UITableViewCellSelectionStyleNone];       
}

Typescript: React event types

I have the following in a types.ts file for html input, select, and textarea:

export type InputChangeEventHandler = React.ChangeEventHandler<HTMLInputElement>
export type TextareaChangeEventHandler = React.ChangeEventHandler<HTMLTextAreaElement>
export type SelectChangeEventHandler = React.ChangeEventHandler<HTMLSelectElement>

Then import them:

import { InputChangeEventHandler } from '../types'

Then use them:


const updateName: InputChangeEventHandler = (event) => {
  // Do something with `event.currentTarget.value`
}
const updateBio: TextareaChangeEventHandler = (event) => {
  // Do something with `event.currentTarget.value`
}
const updateSize: SelectChangeEventHandler = (event) => {
  // Do something with `event.currentTarget.value`
}

Then apply the functions on your markup (replacing ... with other necessary props):

<input onChange={updateName} ... />
<textarea onChange={updateName} ... />
<select onChange={updateSize} ... >
  // ...
</select>

How do I control how Emacs makes backup files?

If you've ever been saved by an Emacs backup file, you probably want more of them, not less of them. It is annoying that they go in the same directory as the file you're editing, but that is easy to change. You can make all backup files go into a directory by putting something like the following in your .emacs.

(setq backup-directory-alist `(("." . "~/.saves")))

There are a number of arcane details associated with how Emacs might create your backup files. Should it rename the original and write out the edited buffer? What if the original is linked? In general, the safest but slowest bet is to always make backups by copying.

(setq backup-by-copying t)

If that's too slow for some reason you might also have a look at backup-by-copying-when-linked.

Since your backups are all in their own place now, you might want more of them, rather than less of them. Have a look at the Emacs documentation for these variables (with C-h v).

(setq delete-old-versions t
  kept-new-versions 6
  kept-old-versions 2
  version-control t)

Finally, if you absolutely must have no backup files:

(setq make-backup-files nil)

It makes me sick to think of it though.

Fragment onResume() & onPause() is not called on backstack

onPause() method works in activity class you can use:

public void onDestroyView(){
super.onDestroyView    
}

for same purpose..

Finding out current index in EACH loop (Ruby)

X.each_with_index do |item, index|
  puts "current_index: #{index}"
end

Symbolicating iPhone App Crash Reports

The combination that worked for me was:

  1. Copy the dSYM file into the directory where the crash report was
  2. Unzip the ipa file containing the app ('unzip MyApp.ipa')
  3. Copy the application binary from the resulting exploded payload into the same folder as the crash report and symbol file (Something like "MyApp.app/MyApp")
  4. Import or Re-symbolicate the crash report from within Xcode's organizer

Using atos I wasn't able to resolve the correct symbol information with the addresses and offsets that were in the crash report. When I did this, I see something more meaningful, and it seems to be a legitimate stack trace.

Java 8 lambda Void argument

Use Supplier if it takes nothing, but returns something.

Use Consumer if it takes something, but returns nothing.

Use Callable if it returns a result and might throw (most akin to Thunk in general CS terms).

Use Runnable if it does neither and cannot throw.

PHP/Apache: PHP Fatal error: Call to undefined function mysql_connect()

I had received a similar error message. Think I inadvertently typed "9o" at start of first line of php.ini file. Once I removed that, I no longer received the "fatal error" messages. Hope this helps.

Understanding implicit in Scala

Also, in the above case there should be only one implicit function whose type is double => Int. Otherwise, the compiler gets confused and won't compile properly.

//this won't compile

implicit def doubleToInt(d: Double) = d.toInt
implicit def doubleToIntSecond(d: Double) = d.toInt
val x: Int = 42.0

How does functools partial do what it does?

This answer is more of an example code. All the above answers give good explanations regarding why one should use partial. I will give my observations and use cases about partial.

from functools import partial
 def adder(a,b,c):
    print('a:{},b:{},c:{}'.format(a,b,c))
    ans = a+b+c
    print(ans)
partial_adder = partial(adder,1,2)
partial_adder(3)  ## now partial_adder is a callable that can take only one argument

Output of the above code should be:

a:1,b:2,c:3
6

Notice that in the above example a new callable was returned that will take parameter (c) as it's argument. Note that it is also the last argument to the function.

args = [1,2]
partial_adder = partial(adder,*args)
partial_adder(3)

Output of the above code is also:

a:1,b:2,c:3
6

Notice that * was used to unpack the non-keyword arguments and the callable returned in terms of which argument it can take is same as above.

Another observation is: Below example demonstrates that partial returns a callable which will take the undeclared parameter (a) as an argument.

def adder(a,b=1,c=2,d=3,e=4):
    print('a:{},b:{},c:{},d:{},e:{}'.format(a,b,c,d,e))
    ans = a+b+c+d+e
    print(ans)
partial_adder = partial(adder,b=10,c=2)
partial_adder(20)

Output of the above code should be:

a:20,b:10,c:2,d:3,e:4
39

Similarly,

kwargs = {'b':10,'c':2}
partial_adder = partial(adder,**kwargs)
partial_adder(20)

Above code prints

a:20,b:10,c:2,d:3,e:4
39

I had to use it when I was using Pool.map_async method from multiprocessing module. You can pass only one argument to the worker function so I had to use partial to make my worker function look like a callable with only one input argument but in reality my worker function had multiple input arguments.

Filter Java Stream to 1 and only 1 element

The other answers that involve writing a custom Collector are probably more efficient (such as Louis Wasserman's, +1), but if you want brevity, I'd suggest the following:

List<User> result = users.stream()
    .filter(user -> user.getId() == 1)
    .limit(2)
    .collect(Collectors.toList());

Then verify the size of the result list.

if (result.size() != 1) {
  throw new IllegalStateException("Expected exactly one user but got " + result);
User user = result.get(0);
}

Int to Decimal Conversion - Insert decimal point at specified location

Simple math.

double result = ((double)number) / 100.0;

Although you may want to use decimal rather than double: decimal vs double! - Which one should I use and when?

How to use Spring Boot with MySQL database and JPA?

I created a project like you did. The structure looks like this

project structure

The Classes are just copy pasted from yours.

I changed the application.properties to this:

spring.datasource.url=jdbc:mysql://localhost/testproject
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=update

But I think your problem is in your pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.1.RELEASE</version>
</parent>

<artifactId>spring-boot-sample-jpa</artifactId>
<name>Spring Boot JPA Sample</name>
<description>Spring Boot JPA Sample</description>

<dependencies>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
</dependencies>
<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

Check these files for differences. Hope this helps

Update 1: I changed my username. The link to the example is now https://github.com/Yannic92/stackOverflowExamples/tree/master/SpringBoot/MySQL

Error: unable to verify the first certificate in nodejs

The server you're trying to download from may be badly configured. Even if it works in your browser, it may not be including all the public certificates in the chain needed for a cache-empty client to verify.

I recommend checking the site in SSLlabs tool: https://www.ssllabs.com/ssltest/

Look for this error:

This server's certificate chain is incomplete.

And this:

Chain issues.........Incomplete

Get safe area inset top and bottom heights

In iOS 11 there is a method that tells when the safeArea has changed.

override func viewSafeAreaInsetsDidChange() {
    super.viewSafeAreaInsetsDidChange()
    let top = view.safeAreaInsets.top
    let bottom = view.safeAreaInsets.bottom
}

How to make code wait while calling asynchronous calls like Ajax

If you need wait until the ajax call is completed all do you need is make your call synchronously.

"string could not resolved" error in Eclipse for C++ (Eclipse can't resolve standard library)

I had this issue with AOSP (clang).

Add external\libcxx\include to includes and _LIBCPP_COMPILER_CLANG to symbols

Retrieving Dictionary Value Best Practices

TryGetValue is slightly faster, because FindEntry will only be called once.

How much faster? It depends on the dataset at hand. When you call the Contains method, Dictionary does an internal search to find its index. If it returns true, you need another index search to get the actual value. When you use TryGetValue, it searches only once for the index and if found, it assigns the value to your variable.

FYI: It's not actually catching an error.

It's calling:

public bool TryGetValue(TKey key, out TValue value)
{
    int index = this.FindEntry(key);
    if (index >= 0)
    {
        value = this.entries[index].value;
        return true;
    }
    value = default(TValue);
    return false;
}

ContainsKey is this:

public bool ContainsKey(TKey key)
{
    return (this.FindEntry(key) >= 0);
}

Proper use of 'yield return'

I know this is an old question, but I'd like to offer one example of how the yield keyword can be creatively used. I have really benefited from this technique. Hopefully this will be of assistance to anyone else who stumbles upon this question.

Note: Don't think about the yield keyword as merely being another way to build a collection. A big part of the power of yield comes in the fact that execution is paused in your method or property until the calling code iterates over the next value. Here's my example:

Using the yield keyword (alongside Rob Eisenburg's Caliburn.Micro coroutines implementation) allows me to express an asynchronous call to a web service like this:

public IEnumerable<IResult> HandleButtonClick() {
    yield return Show.Busy();

    var loginCall = new LoginResult(wsClient, Username, Password);
    yield return loginCall;
    this.IsLoggedIn = loginCall.Success;

    yield return Show.NotBusy();
}

What this will do is turn my BusyIndicator on, call the Login method on my web service, set my IsLoggedIn flag to the return value, and then turn the BusyIndicator back off.

Here's how this works: IResult has an Execute method and a Completed event. Caliburn.Micro grabs the IEnumerator from the call to HandleButtonClick() and passes it into a Coroutine.BeginExecute method. The BeginExecute method starts iterating through the IResults. When the first IResult is returned, execution is paused inside HandleButtonClick(), and BeginExecute() attaches an event handler to the Completed event and calls Execute(). IResult.Execute() can perform either a synchronous or an asynchronous task and fires the Completed event when it's done.

LoginResult looks something like this:

public LoginResult : IResult {
    // Constructor to set private members...

    public void Execute(ActionExecutionContext context) {
        wsClient.LoginCompleted += (sender, e) => {
            this.Success = e.Result;
            Completed(this, new ResultCompletionEventArgs());
        };
        wsClient.Login(username, password);
    }

    public event EventHandler<ResultCompletionEventArgs> Completed = delegate { };
    public bool Success { get; private set; }
}

It may help to set up something like this and step through the execution to watch what's going on.

Hope this helps someone out! I've really enjoyed exploring the different ways yield can be used.

How to dynamically add and remove form fields in Angular 2

This is a few months late but I thought I'd provide my solution based on this here tutorial. The gist of it is that it's a lot easier to manage once you change the way you approach forms.

First, use ReactiveFormsModule instead of or in addition to the normal FormsModule. With reactive forms you create your forms in your components/services and then plug them into your page instead of your page generating the form itself. It's a bit more code but it's a lot more testable, a lot more flexible, and as far as I can tell the best way to make a lot of non-trivial forms.

The end result will look a little like this, conceptually:

  • You have one base FormGroup with whatever FormControl instances you need for the entirety of the form. For example, as in the tutorial I linked to, lets say you want a form where a user can input their name once and then any number of addresses. All of the one-time field inputs would be in this base form group.

  • Inside that FormGroup instance there will be one or more FormArray instances. A FormArray is basically a way to group multiple controls together and iterate over them. You can also put multiple FormGroup instances in your array and use those as essentially "mini-forms" nested within your larger form.

  • By nesting multiple FormGroup and/or FormControl instances within a dynamic FormArray, you can control validity and manage the form as one, big, reactive piece made up of several dynamic parts. For example, if you want to check if every single input is valid before allowing the user to submit, the validity of one sub-form will "bubble up" to the top-level form and the entire form becomes invalid, making it easy to manage dynamic inputs.

  • As a FormArray is, essentially, a wrapper around an array interface but for form pieces, you can push, pop, insert, and remove controls at any time without recreating the form or doing complex interactions.

In case the tutorial I linked to goes down, here some sample code you can implement yourself (my examples use TypeScript) that illustrate the basic ideas:

Base Component code:

import { Component, Input, OnInit } from '@angular/core';
import { FormArray, FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'my-form-component',
  templateUrl: './my-form.component.html'
})
export class MyFormComponent implements OnInit {
    @Input() inputArray: ArrayType[];
    myForm: FormGroup;

    constructor(private fb: FormBuilder) {}
    ngOnInit(): void {
        let newForm = this.fb.group({
            appearsOnce: ['InitialValue', [Validators.required, Validators.maxLength(25)]],
            formArray: this.fb.array([])
        });

        const arrayControl = <FormArray>newForm.controls['formArray'];
        this.inputArray.forEach(item => {
            let newGroup = this.fb.group({
                itemPropertyOne: ['InitialValue', [Validators.required]],
                itemPropertyTwo: ['InitialValue', [Validators.minLength(5), Validators.maxLength(20)]]
            });
            arrayControl.push(newGroup);
        });

        this.myForm = newForm;
    }
    addInput(): void {
        const arrayControl = <FormArray>this.myForm.controls['formArray'];
        let newGroup = this.fb.group({

            /* Fill this in identically to the one in ngOnInit */

        });
        arrayControl.push(newGroup);
    }
    delInput(index: number): void {
        const arrayControl = <FormArray>this.myForm.controls['formArray'];
        arrayControl.removeAt(index);
    }
    onSubmit(): void {
        console.log(this.myForm.value);
        // Your form value is outputted as a JavaScript object.
        // Parse it as JSON or take the values necessary to use as you like
    }
}

Sub-Component Code: (one for each new input field, to keep things clean)

import { Component, Input } from '@angular/core';
import { FormGroup } from '@angular/forms';

@Component({
    selector: 'my-form-sub-component',
    templateUrl: './my-form-sub-component.html'
})
export class MyFormSubComponent {
    @Input() myForm: FormGroup; // This component is passed a FormGroup from the base component template
}

Base Component HTML

<form [formGroup]="myForm" (ngSubmit)="onSubmit()" novalidate>
    <label>Appears Once:</label>
    <input type="text" formControlName="appearsOnce" />

    <div formArrayName="formArray">
        <div *ngFor="let control of myForm.controls['formArray'].controls; let i = index">
            <button type="button" (click)="delInput(i)">Delete</button>
            <my-form-sub-component [myForm]="myForm.controls.formArray.controls[i]"></my-form-sub-component>
        </div>
    </div>
    <button type="button" (click)="addInput()">Add</button>
    <button type="submit" [disabled]="!myForm.valid">Save</button>
</form>

Sub-Component HTML

<div [formGroup]="form">
    <label>Property One: </label>
    <input type="text" formControlName="propertyOne"/>

    <label >Property Two: </label>
    <input type="number" formControlName="propertyTwo"/>
</div>

In the above code I basically have a component that represents the base of the form and then each sub-component manages its own FormGroup instance within the FormArray situated inside the base FormGroup. The base template passes along the sub-group to the sub-component and then you can handle validation for the entire form dynamically.

Also, this makes it trivial to re-order component by strategically inserting and removing them from the form. It works with (seemingly) any number of inputs as they don't conflict with names (a big downside of template-driven forms as far as I'm aware) and you still retain pretty much automatic validation. The only "downside" of this approach is, besides writing a little more code, you do have to relearn how forms work. However, this will open up possibilities for much larger and more dynamic forms as you go on.

If you have any questions or want to point out some errors, go ahead. I just typed up the above code based on something I did myself this past week with the names changed and other misc. properties left out, but it should be straightforward. The only major difference between the above code and my own is that I moved all of the form-building to a separate service that's called from the component so it's a bit less messy.

How to include duplicate keys in HashMap?

hashMaps can't have duplicate keys. That said, you can create a map with list values:

Map<Integer, List<String>>

However, using this approach will have performance implications.

How can I export the schema of a database in PostgreSQL?

You should use something like this pg_dump --schema=your_schema_name db1, for details take a look here

Multiprocessing a for loop?

You can simply use multiprocessing.Pool:

from multiprocessing import Pool

def process_image(name):
    sci=fits.open('{}.fits'.format(name))
    <process>

if __name__ == '__main__':
    pool = Pool()                         # Create a multiprocessing Pool
    pool.map(process_image, data_inputs)  # process data_inputs iterable with pool

How do you access the element HTML from within an Angular attribute directive?

So actually, my comment that you should do a console.log(el.nativeElement) should have pointed you in the right direction, but I didn't expect the output to be just a string representing the DOM Element.

What you have to do to inspect it in the way it helps you with your problem, is to do a console.log(el) in your example, then you'll have access to the nativeElement object and will see a property called innerHTML.

Which will lead to the answer to your original question:

let myCurrentContent:string = el.nativeElement.innerHTML; // get the content of your element
el.nativeElement.innerHTML = 'my new content'; // set content of your element

Update for better approach:

Since it's the accepted answer and web workers are getting more important day to day (and it's considered best practice anyway) I want to add this suggestion by Mark Rajcok here.

The best way to manipulate DOM Elements programmatically is using the Renderer:

constructor(private _elemRef: ElementRef, private _renderer: Renderer) { 
    this._renderer.setElementProperty(this._elemRef.nativeElement, 'innerHTML', 'my new content');
}

Edit

Since Renderer is deprecated now, use Renderer2 instead with setProperty


Update:

This question with its answer explained the console.log behavior.

Which means that console.dir(el.nativeElement) would be the more direct way of accessing the DOM Element as an "inspectable" Object in your console for this situation.


Hope this helped.

How to drop a PostgreSQL database if there are active connections to it?

Nothing worked for me except, I loggined using pgAdmin4 and on the Dashboard I disconnected all connections except pgAdmin4 and then was able to rename by right lick on the database and properties and typed new name.

How Do I Uninstall Yarn

npm uninstall yarn removes the yarn packages that are installed via npm but what yarn does underneath the hood is, it installs a software named yarn in your PC. If you have installed in Windows, Go to add or remove programs and then search for yarn and uninstall it then you are good to go.

Ant build failed: "Target "build..xml" does not exist"

I'm probably late but this worked for me:


  1. Open your build.xml file located in your project's directory.
  2. Copy and Paste the following code in the main project tag : <target name="build" />

Progress during large file copy (Copy-Item & Write-Progress?)

This recursive function copies files and directories recursively from source path to destination path

If file already exists on destination path, it copies them only with newer files.

Function Copy-FilesBitsTransfer(
        [Parameter(Mandatory=$true)][String]$sourcePath, 
        [Parameter(Mandatory=$true)][String]$destinationPath, 
        [Parameter(Mandatory=$false)][bool]$createRootDirectory = $true)
{
    $item = Get-Item $sourcePath
    $itemName = Split-Path $sourcePath -leaf
    if (!$item.PSIsContainer){ #Item Is a file

        $clientFileTime = Get-Item $sourcePath | select LastWriteTime -ExpandProperty LastWriteTime

        if (!(Test-Path -Path $destinationPath\$itemName)){
            Start-BitsTransfer -Source $sourcePath -Destination $destinationPath -Description "$sourcePath >> $destinationPath" -DisplayName "Copy Template file" -Confirm:$false
            if (!$?){
                return $false
            }
        }
        else{
            $serverFileTime = Get-Item $destinationPath\$itemName | select LastWriteTime -ExpandProperty LastWriteTime

            if ($serverFileTime -lt $clientFileTime)
            {
                Start-BitsTransfer -Source $sourcePath -Destination $destinationPath -Description "$sourcePath >> $destinationPath" -DisplayName "Copy Template file" -Confirm:$false
                if (!$?){
                    return $false
                }
            }
        }
    }
    else{ #Item Is a directory
        if ($createRootDirectory){
            $destinationPath = "$destinationPath\$itemName"
            if (!(Test-Path -Path $destinationPath -PathType Container)){
                if (Test-Path -Path $destinationPath -PathType Leaf){ #In case item is a file, delete it.
                    Remove-Item -Path $destinationPath
                }

                New-Item -ItemType Directory $destinationPath | Out-Null
                if (!$?){
                    return $false
                }

            }
        }
        Foreach ($fileOrDirectory in (Get-Item -Path "$sourcePath\*"))
        {
            $status = Copy-FilesBitsTransfer $fileOrDirectory $destinationPath $true
            if (!$status){
                return $false
            }
        }
    }

    return $true
}

Retrieve all values from HashMap keys in an ArrayList Java

Java 8 solution for produce string like "key1: value1,key2: value2"

private static String hashMapToString(HashMap<String, String> hashMap) {

    return hashMap.keySet().stream()
            .map((key) -> key + ": " + hashMap.get(key))
            .collect(Collectors.joining(","));

}

and produce a list simple collect as list

private static List<String> hashMapToList(HashMap<String, String> hashMap) {

    return hashMap.keySet().stream()
            .map((key) -> key + ": " + hashMap.get(key))
            .collect(Collectors.toList());

}

ASP.Net MVC How to pass data from view to controller

In case you don't want/need to post:

@Html.ActionLink("link caption", "actionName", new { Model.Page })  // view's controller
@Html.ActionLink("link caption", "actionName", "controllerName", new { reportID = 1 }, null);

[HttpGet]
public ActionResult actionName(int reportID)
{

Note that the reportID in the new {} part matches reportID in the action parameters, you can add any number of parameters this way, but any more than 2 or 3 (some will argue always) you should be passing a model via a POST (as per other answer)

Edit: Added null for correct overload as pointed out in comments. There's a number of overloads and if you specify both action+controller, then you need both routeValues and htmlAttributes. Without the controller (just caption+action), only routeValues are needed but may be best practice to always specify both.

database vs. flat files

They're faster; unless you're loading the entire flat file into memory, a database will allow faster access in almost all cases.

They're safer; databases are easier to safely backup; they have mechanisms to check for file corruption, which flat files do not. Once corruption in your flat file migrates to your backups, you're done, and you might not even know it yet.

They have more features; databases can allow many users to read/write at the same time.

They're much less complex to work with, once they're setup.

Show and hide a View with a slide up/down animation

Now visibility change animations should be done via Transition API which available in support (androidx) package. Just call TransitionManager.beginDelayedTransition method with Slide transition then change visibility of the view.

enter image description here

import androidx.transition.Slide;
import androidx.transition.Transition;
import androidx.transition.TransitionManager;

private void toggle(boolean show) {
    View redLayout = findViewById(R.id.redLayout);
    ViewGroup parent = findViewById(R.id.parent);

    Transition transition = new Slide(Gravity.BOTTOM);
    transition.setDuration(600);
    transition.addTarget(R.id.redLayout);

    TransitionManager.beginDelayedTransition(parent, transition);
    redLayout.setVisibility(show ? View.VISIBLE : View.GONE);
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/parent"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="play" />

    <LinearLayout
        android:id="@+id/redLayout"
        android:layout_width="match_parent"
        android:layout_height="400dp"
        android:background="#5f00"
        android:layout_alignParentBottom="true" />
</RelativeLayout>

Check this answer with another default and custom transition examples.

What is the difference between vmalloc and kmalloc?

One of other differences is kmalloc will return logical address (else you specify GPF_HIGHMEM). Logical addresses are placed in "low memory" (in the first gigabyte of physical memory) and are mapped directly to physical addresses (use __pa macro to convert it). This property implies kmalloced memory is continuous memory.

In other hand, Vmalloc is able to return virtual addresses from "high memory". These addresses cannot be converted in physical addresses in a direct fashion (you have to use virt_to_page function).

Define: What is a HashSet?

A HashSet has an internal structure (hash), where items can be searched and identified quickly. The downside is that iterating through a HashSet (or getting an item by index) is rather slow.

So why would someone want be able to know if an entry already exists in a set?

One situation where a HashSet is useful is in getting distinct values from a list where duplicates may exist. Once an item is added to the HashSet it is quick to determine if the item exists (Contains operator).

Other advantages of the HashSet are the Set operations: IntersectWith, IsSubsetOf, IsSupersetOf, Overlaps, SymmetricExceptWith, UnionWith.

If you are familiar with the object constraint language then you will identify these set operations. You will also see that it is one step closer to an implementation of executable UML.

Regex AND operator

Maybe just an OR operator | could be enough for your problem:

String: foo,bar,baz

Regex: (foo)|(baz)

Result: ["foo", "baz"]

Using sed, how do you print the first 'N' characters of a line?

colrm x

For example, if you need the first 100 characters:

cat file |colrm 101 

It's been around for years and is in most linux's and bsd's (freebsd for sure), usually by default. I can't remember ever having to type apt-get install colrm.

How to access the GET parameters after "?" in Express?

A nice technique i've started using with some of my apps on express is to create an object which merges the query, params, and body fields of express's request object.

//./express-data.js
const _ = require("lodash");

class ExpressData {

    /*
    * @param {Object} req - express request object
    */
    constructor (req) {

        //Merge all data passed by the client in the request
        this.props = _.merge(req.body, req.params, req.query);
     }

}

module.exports = ExpressData;

Then in your controller body, or anywhere else in scope of the express request chain, you can use something like below:

//./some-controller.js

const ExpressData = require("./express-data.js");
const router = require("express").Router();


router.get("/:some_id", (req, res) => {

    let props = new ExpressData(req).props;

    //Given the request "/592363122?foo=bar&hello=world"
    //the below would log out 
    // {
    //   some_id: 592363122,
    //   foo: 'bar',
    //   hello: 'world'
    // }
    console.log(props);

    return res.json(props);
});

This makes it nice and handy to just "delve" into all of the "custom data" a user may have sent up with their request.

Note

Why the 'props' field? Because that was a cut-down snippet, I use this technique in a number of my APIs, I also store authentication / authorisation data onto this object, example below.

/*
 * @param {Object} req - Request response object
*/
class ExpressData {

    /*
    * @param {Object} req - express request object
    */
    constructor (req) {

        //Merge all data passed by the client in the request
        this.props = _.merge(req.body, req.params, req.query);

        //Store reference to the user
        this.user = req.user || null;

        //API connected devices (Mobile app..) will send x-client header with requests, web context is implied.
        //This is used to determine how the user is connecting to the API 
        this.client = (req.headers) ? (req.headers["x-client"] || (req.client || "web")) : "web";
    }
} 

Image Processing: Algorithm Improvement for 'Coca-Cola Can' Recognition

Maybe too many years late, but nevertheless a theory to try.

The ratio of bounding rectangle of red logo region to the overall dimension of the bottle/can is different. In the case of Can, should be 1:1, whereas will be different in that of bottle (with or without cap). This should make it easy to distinguish between the two.

Update: The horizontal curvature of the logo region will be different between the Can and Bottle due their respective size difference. This could be specifically useful if your robot needs to pick up can/bottle, and you decide the grip accordingly.

Check if a varchar is a number (TSQL)

Do not forget to exclude carriage returns from your data !!!

as in:

SELECT 
  Myotherval
  , CASE WHEN TRIM(REPLACE([MyVal], char(13) + char(10), '')) not like '%[^0-9]%' and RTRIM(REPLACE([MyVal], char(13) + char(10), '')) not like '.' and isnumeric(REPLACE([MyVal], char(13) + char(10), '')) = 1 THEN 'my number: ' +  [MyVal]
             ELSE ISNULL(Cast([MyVal] AS VARCHAR(8000)), '')
        END AS 'MyVal'
FROM MyTable

Eclipse and Windows newlines

In addition to the Eclipse solutions and the tool mentioned in another answer, consider flip. It can 'flip' either way between normal and Windows linebreaks, and does nice things like preserve the file's timestamp and other stats.

You can use it like this to solve your problem:

find . -type f -not -path './.git/*' -exec flip -u {} \;

(I put in a clause to ignore your .git directory, in case you use git, but since flip ignores binary files by default, you mightn't need this.)

How to keep environment variables when using sudo

For individual variables you want to make available on a one off basis you can make it part of the command.

sudo http_proxy=$http_proxy wget "http://stackoverflow.com"