Programs & Examples On #Taint

Sniffing/logging your own Android Bluetooth traffic

Also, this might help finding the actual location the btsnoop_hci.log is being saved:

adb shell "cat /etc/bluetooth/bt_stack.conf | grep FileName"

Tainted canvases may not be exported

I also solved this error by adding useCORS : true, in my code like -

html2canvas($("#chart-section")[0], {
        useCORS : true,
        allowTaint : true,
        scale : 0.98,
        dpi : 500,
        width: 1400, height: 900
    }).then();

How to fix getImageData() error The canvas has been tainted by cross-origin data?

You won't be able to draw images directly from another server into a canvas and then use getImageData. It's a security issue and the canvas will be considered "tainted".

Would it work for you to save a copy of the image to your server using PHP and then just load the new image? For example, you could send the URL to the PHP script and save it to your server, then return the new filename to your javascript like this:

<?php //The name of this file in this example is imgdata.php

  $url=$_GET['url'];

  // prevent hackers from uploading PHP scripts and pwning your system
  if(!@is_array(getimagesize($url))){
    echo "path/to/placeholderImage.png";
    exit("wrong file type.");
  }

  $img = file_get_contents($url);

  $fn = substr(strrchr($url, "/"), 1);
  file_put_contents($fn,$img);
  echo $fn;

?>

You'd use the PHP script with some ajax javascript like this:

xi=new XMLHttpRequest();
xi.open("GET","imgdata.php?url="+yourImageURL,true);
xi.send();

xi.onreadystatechange=function() {
  if(xi.readyState==4 && xi.status==200) {
    img=new Image;
    img.onload=function(){ 
      ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
    }
    img.src=xi.responseText;
  }
}

If you use getImageData on the canvas after that, it will work fine.

Alternatively, if you don't want to save the whole image, you could pass x & y coordinates to your PHP script and calculate the pixel's rgba value on that side. I think there are good libraries for doing that kind of image processing in PHP.

If you want to use this approach, let me know if you need help implementing it.

edit-1: peeps pointed out that the php script is exposed and allows the internet to potentially use it maliciously. there are a million ways to handle this, one of the simplest being some sort of URL obfuscation... i reckon secure php practices deserves a separate google ;P

edit-2: by popular demand, I've added a check to ensure it is an image and not a php script (from: PHP check if file is an image).

How to resolve "could not execute statement; SQL [n/a]; constraint [numbering];"?

In my case, I was fetching data from database, changing some column values and updating it in database but for updating I was using the same save query which was violating primary key constraints i.e duplicate values for primary key, so I had written a separate query for updating the columns and it solved my problem..!

How to POST raw whole JSON in the body of a Retrofit request?

This is what works me for the current version of retrofit 2.6.2,

First of all, we need to add a Scalars Converter to the list of our Gradle dependencies, which would take care of converting java.lang.String objects to text/plain request bodies,

implementation'com.squareup.retrofit2:converter-scalars:2.6.2'

Then, we need to pass a converter factory to our Retrofit builder. It will later tell Retrofit how to convert the @Body parameter passed to the service.

private val retrofitBuilder: Retrofit.Builder by lazy {
    Retrofit.Builder()
        .baseUrl(BASE_URL)
        .addConverterFactory(ScalarsConverterFactory.create())
        .addConverterFactory(GsonConverterFactory.create())
}

Note: In my retrofit builder i have two converters Gson and Scalars you can use both of them but to send Json body we need to focus Scalars so if you don't need Gson remove it

Then Retrofit service with a String body parameter.

@Headers("Content-Type: application/json")
@POST("users")
fun saveUser(@Body   user: String): Response<MyResponse>

Then create the JSON body

val user = JsonObject()
 user.addProperty("id", 001)
 user.addProperty("name", "Name")

Call your service

RetrofitService.myApi.saveUser(user.toString())

canvas.toDataURL() SecurityError

By using fabric js we can solve this security error issue in IE.

    function getBase64FromImageUrl(URL) {
        var canvas  = new fabric.Canvas('c');
        var img = new Image();
        img.onload = function() {
            var canvas1 = document.createElement("canvas");
            canvas1.width = this.width;
            canvas1.height = this.height;
            var ctx = canvas.getContext('2d');
            ctx.drawImage(this, 0, 0);
            var dataURL = canvas.toDataURL({format: "png"});
        };
        img.src = URL;
    }

How to execute a stored procedure inside a select query

Functions are easy to call inside a select loop, but they don't let you run inserts, updates, deletes, etc. They are only useful for query operations. You need a stored procedure to manipulate the data.

So, the real answer to this question is that you must iterate through the results of a select statement via a "cursor" and call the procedure from within that loop. Here's an example:

DECLARE @myId int;
DECLARE @myName nvarchar(60);
DECLARE myCursor CURSOR FORWARD_ONLY FOR
    SELECT Id, Name FROM SomeTable;
OPEN myCursor;
FETCH NEXT FROM myCursor INTO @myId, @myName;
WHILE @@FETCH_STATUS = 0 BEGIN
    EXECUTE dbo.myCustomProcedure @myId, @myName;
    FETCH NEXT FROM myCursor INTO @myId, @myName;
END;
CLOSE myCursor;
DEALLOCATE myCursor;

Note that @@FETCH_STATUS is a standard variable which gets updated for you. The rest of the object names here are custom.

Understanding the Linux oom-killer's logs

Memory management in Linux is a bit tricky to understand, and I can't say I fully understand it yet, but I'll try to share a little bit of my experience and knowledge.

Short answer to your question: Yes there are other stuff included than whats in the list.

What's being shown in your list is applications run in userspace. The kernel uses memory for itself and modules, on top of that it also has a lower limit of free memory that you can't go under. When you've reached that level it will try to free up resources, and when it can't do that anymore, you end up with an OOM problem.

From the last line of your list you can read that the kernel reports a total-vm usage of: 1498536kB (1,5GB), where the total-vm includes both your physical RAM and swap space. You stated you don't have any swap but the kernel seems to think otherwise since your swap space is reported to be full (Total swap = 524284kB, Free swap = 0kB) and it reports a total vmem size of 1,5GB.

Another thing that can complicate things further is memory fragmentation. You can hit the OOM killer when the kernel tries to allocate lets say 4096kB of continous memory, but there are no free ones availible.

Now that alone probably won't help you solve the actual problem. I don't know if it's normal for your program to require that amount of memory, but I would recommend to try a static code analyzer like cppcheck to check for memory leaks or file descriptor leaks. You could also try to run it through Valgrind to get a bit more information out about memory usage.

Create a unique number with javascript time

This creates an almost guaranteed unique 32 character key client side, if you want just numbers change the "chars" var.

var d = new Date().valueOf();
var n = d.toString();
var result = '';
var length = 32;
var p = 0;
var chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';

for (var i = length; i > 0; --i){
    result += ((i & 1) && n.charAt(p) ? '<b>' + n.charAt(p) + '</b>' : chars[Math.floor(Math.random() * chars.length)]);
    if(i & 1) p++;
};

https://jsfiddle.net/j0evrdf1/1/

Creating threads - Task.Factory.StartNew vs new Thread()

The task gives you all the goodness of the task API:

  • Adding continuations (Task.ContinueWith)
  • Waiting for multiple tasks to complete (either all or any)
  • Capturing errors in the task and interrogating them later
  • Capturing cancellation (and allowing you to specify cancellation to start with)
  • Potentially having a return value
  • Using await in C# 5
  • Better control over scheduling (if it's going to be long-running, say so when you create the task so the task scheduler can take that into account)

Note that in both cases you can make your code slightly simpler with method group conversions:

DataInThread = new Thread(ThreadProcedure);
// Or...
Task t = Task.Factory.StartNew(ThreadProcedure);

Using json_encode on objects in PHP (regardless of scope)

In PHP >= 5.4.0 there is a new interface for serializing objects to JSON : JsonSerializable

Just implement the interface in your object and define a JsonSerializable method which will be called when you use json_encode.

So the solution for PHP >= 5.4.0 should look something like this:

class JsonObject implements JsonSerializable
{
    // properties

    // function called when encoded with json_encode
    public function jsonSerialize()
    {
        return get_object_vars($this);
    }
}

Curl setting Content-Type incorrectly

I think you want to specify

-H "Content-Type:text/xml"

with a colon, not an equals.

Is the Scala 2.8 collections library a case of "the longest suicide note in history"?

One way that the Scala community can help ease the fear of programmers new to Scala is to focus on practice and to teach by example--a lot of examples that start small and grow gradually larger. Here are a few sites that take this approach:

After spending some time on these sites, one quickly realizes that Scala and its libraries, though perhaps difficult to design and implement, are not so difficult to use, especially in the common cases.

ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)

Added to TruelyObservableCollection event "ItemPropertyChanged":

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel; // ObservableCollection
using System.ComponentModel; // INotifyPropertyChanged
using System.Collections.Specialized; // NotifyCollectionChangedEventHandler
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ObservableCollectionTest
{
    class Program
    {
        static void Main(string[] args)
        {
            // ATTN: Please note it's a "TrulyObservableCollection" that's instantiated. Otherwise, "Trades[0].Qty = 999" will NOT trigger event handler "Trades_CollectionChanged" in main.
            // REF: http://stackoverflow.com/questions/8490533/notify-observablecollection-when-item-changes
            TrulyObservableCollection<Trade> Trades = new TrulyObservableCollection<Trade>();
            Trades.Add(new Trade { Symbol = "APPL", Qty = 123 });
            Trades.Add(new Trade { Symbol = "IBM", Qty = 456});
            Trades.Add(new Trade { Symbol = "CSCO", Qty = 789 });

            Trades.CollectionChanged += Trades_CollectionChanged;
            Trades.ItemPropertyChanged += PropertyChangedHandler;
            Trades.RemoveAt(2);

            Trades[0].Qty = 999;

            Console.WriteLine("Hit any key to exit");
            Console.ReadLine();

            return;
        }

        static void PropertyChangedHandler(object sender, PropertyChangedEventArgs e)
        {
            Console.WriteLine(DateTime.Now.ToString() + ", Property changed: " + e.PropertyName + ", Symbol: " + ((Trade) sender).Symbol + ", Qty: " + ((Trade) sender).Qty);
            return;
        }

        static void Trades_CollectionChanged(object sender, EventArgs e)
        {
            Console.WriteLine(DateTime.Now.ToString() + ", Collection changed");
            return;
        }
    }

    #region TrulyObservableCollection
    public class TrulyObservableCollection<T> : ObservableCollection<T>
        where T : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler ItemPropertyChanged;

        public TrulyObservableCollection()
            : base()
        {
            CollectionChanged += new NotifyCollectionChangedEventHandler(TrulyObservableCollection_CollectionChanged);
        }

        void TrulyObservableCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.NewItems != null)
            {
                foreach (Object item in e.NewItems)
                {
                    (item as INotifyPropertyChanged).PropertyChanged += new PropertyChangedEventHandler(item_PropertyChanged);
                }
            }
            if (e.OldItems != null)
            {
                foreach (Object item in e.OldItems)
                {
                    (item as INotifyPropertyChanged).PropertyChanged -= new PropertyChangedEventHandler(item_PropertyChanged);
                }
            }
        }

        void item_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            NotifyCollectionChangedEventArgs a = new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset);
            OnCollectionChanged(a);

            if (ItemPropertyChanged != null)
            {
                ItemPropertyChanged(sender, e);
            }
        }
    }
    #endregion

    #region Sample entity
    class Trade : INotifyPropertyChanged
    {
        protected string _Symbol;
        protected int _Qty = 0;
        protected DateTime _OrderPlaced = DateTime.Now;

        public DateTime OrderPlaced
        {
            get { return _OrderPlaced; }
        }

        public string Symbol
        {
            get
            {
                return _Symbol;
            }
            set
            {
                _Symbol = value;
                NotifyPropertyChanged("Symbol");
            }
        }

        public int Qty
        {
            get
            {
                return _Qty;
            }
            set
            {
                _Qty = value;
                NotifyPropertyChanged("Qty");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String propertyName = "")
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
#endregion
}

How do I return multiple values from a function?

I prefer to use tuples whenever a tuple feels "natural"; coordinates are a typical example, where the separate objects can stand on their own, e.g. in one-axis only scaling calculations, and the order is important. Note: if I can sort or shuffle the items without an adverse effect to the meaning of the group, then I probably shouldn't use a tuple.

I use dictionaries as a return value only when the grouped objects aren't always the same. Think optional email headers.

For the rest of the cases, where the grouped objects have inherent meaning inside the group or a fully-fledged object with its own methods is needed, I use a class.

How do I create a user account for basic authentication?

If you create a user with the advanced user management (from command line: netplwiz), then modify the group, remove users, and add iis_users. They will be able to authenticate to your web page, but not the computer.

How to implement Enums in Ruby?

It all depends how you use Java or C# enums. How you use it will dictate the solution you'll choose in Ruby.

Try the native Set type, for instance:

>> enum = Set['a', 'b', 'c']
=> #<Set: {"a", "b", "c"}>
>> enum.member? "b"
=> true
>> enum.member? "d"
=> false
>> enum.add? "b"
=> nil
>> enum.add? "d"
=> #<Set: {"a", "b", "c", "d"}>

Case-insensitive search

If you are concerned about the "unterminated character class" case, removing all non-alphanumeric chars would be helpful:

searchstring = searchstring.replace(/[^a-zA-Z 0-9]+/g,'');

how to convert long date value to mm/dd/yyyy format

Try this example

 String[] formats = new String[] {
   "yyyy-MM-dd",
   "yyyy-MM-dd HH:mm",
   "yyyy-MM-dd HH:mmZ",
   "yyyy-MM-dd HH:mm:ss.SSSZ",
   "yyyy-MM-dd'T'HH:mm:ss.SSSZ",
 };
 for (String format : formats) {
   SimpleDateFormat sdf = new SimpleDateFormat(format, Locale.US);
   System.err.format("%30s %s\n", format, sdf.format(new Date(0)));
   sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
   System.err.format("%30s %s\n", format, sdf.format(new Date(0)));
 }

and read this http://developer.android.com/reference/java/text/SimpleDateFormat.html

How can I set the aspect ratio in matplotlib?

This answer is based on Yann's answer. It will set the aspect ratio for linear or log-log plots. I've used additional information from https://stackoverflow.com/a/16290035/2966723 to test if the axes are log-scale.

def forceAspect(ax,aspect=1):
    #aspect is width/height
    scale_str = ax.get_yaxis().get_scale()
    xmin,xmax = ax.get_xlim()
    ymin,ymax = ax.get_ylim()
    if scale_str=='linear':
        asp = abs((xmax-xmin)/(ymax-ymin))/aspect
    elif scale_str=='log':
        asp = abs((scipy.log(xmax)-scipy.log(xmin))/(scipy.log(ymax)-scipy.log(ymin)))/aspect
    ax.set_aspect(asp)

Obviously you can use any version of log you want, I've used scipy, but numpy or math should be fine.

re.sub erroring with "Expected string or bytes-like object"

I suppose better would be to use re.match() function. here is an example which may help you.

import re
import nltk
from nltk.tokenize import word_tokenize
nltk.download('punkt')
sentences = word_tokenize("I love to learn NLP \n 'a :(")
#for i in range(len(sentences)):
sentences = [word.lower() for word in sentences if re.match('^[a-zA-Z]+', word)]  
sentences

How to access List elements

Learn python the hard way ex 34

try this

animals = ['bear' , 'python' , 'peacock', 'kangaroo' , 'whale' , 'platypus']

# print "The first (1st) animal is at 0 and is a bear." 

for i in range(len(animals)):
    print "The %d animal is at %d and is a %s" % (i+1 ,i, animals[i])

# "The animal at 0 is the 1st animal and is a bear."

for i in range(len(animals)):
    print "The animal at %d is the %d and is a %s " % (i, i+1, animals[i])

How can I switch my git repository to a particular commit

Just checkout the commit you wants your new branch start from and create a new branch

git checkout -b newbranch 6e559cb95

How do you create a yes/no boolean field in SQL server?

The equivalent is a BIT field.

In SQL you use 0 and 1 to set a bit field (just as a yes/no field in Access). In Management Studio it displays as a false/true value (at least in recent versions).

When accessing the database through ASP.NET it will expose the field as a boolean value.

Dictionary text file

What about /usr/share/dict/words on any Unix system? How many words are we talking about? Like OED-Unabridged?

How to detect if a string contains special characters?

Assuming SQL Server:

e.g. if you class special characters as anything NOT alphanumeric:

DECLARE @MyString VARCHAR(100)
SET @MyString = 'adgkjb$'

IF (@MyString LIKE '%[^a-zA-Z0-9]%')
    PRINT 'Contains "special" characters'
ELSE
    PRINT 'Does not contain "special" characters'

Just add to other characters you don't class as special, inside the square brackets

How do I get the directory that a program is running from?

Just my two cents, but doesn't the following code portably work in C++17?

#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;

int main(int argc, char* argv[])
{
    std::cout << "Path is " << fs::path(argv[0]).parent_path() << '\n';
}

Seems to work for me on Linux at least.

Based on the previous idea, I now have:

std::filesystem::path prepend_exe_path(const std::string& filename, const std::string& exe_path = "");

With implementation:

fs::path prepend_exe_path(const std::string& filename, const std::string& exe_path)
{
    static auto exe_parent_path = fs::path(exe_path).parent_path();
    return exe_parent_path / filename;
}

And initialization trick in main():

(void) prepend_exe_path("", argv[0]);

Thanks @Sam Redway for the argv[0] idea. And of course, I understand that C++17 was not around for many years when the OP asked the question.

How to display an image stored as byte array in HTML/JavaScript?

Try putting this HTML snippet into your served document:

<img id="ItemPreview" src="">

Then, on JavaScript side, you can dynamically modify image's src attribute with so-called Data URL.

document.getElementById("ItemPreview").src = "data:image/png;base64," + yourByteArrayAsBase64;

Alternatively, using jQuery:

$('#ItemPreview').attr('src', `data:image/png;base64,${yourByteArrayAsBase64}`);

This assumes that your image is stored in PNG format, which is quite popular. If you use some other image format (e.g. JPEG), modify the MIME type ("image/..." part) in the URL accordingly.

Similar Questions:

How to completely remove Python from a Windows machine?

It's actually quite simple. When you installed it, you must have done it using some .exe file (I am assuming). Just run that .exe again, and then there will be options to modify Python. Just select the "Complete Uninstall" option, and the EXE will completely wipe out python for you.

Also, you might have to checkbox the "Remove Python from PATH". By default it is selected, but you may as well check it to be sure :)

git - remote add origin vs remote set-url origin

Try this:

git init  
git remote add origin your_repo.git  
git remote -v  
git status  

What does -> mean in C++?

  1. Access operator applicable to (a) all pointer types, (b) all types which explicitely overload this operator
  2. Introducer for the return type of a local lambda expression:

    std::vector<MyType> seq;
    // fill with instances...  
    std::sort(seq.begin(), seq.end(),
                [] (const MyType& a, const MyType& b) -> bool {
                    return a.Content < b.Content;
                });
    
  3. introducing a trailing return type of a function in combination of the re-invented auto:

    struct MyType {
        // declares a member function returning std::string
        auto foo(int) -> std::string;
    };
    

firefox proxy settings via command line

I needed to set an additional option to allow SSO passthrough to our intranet site. I added some code to an example above.

pushd "%APPDATA%\Mozilla\Firefox\Profiles\*.default"
echo user_pref("network.proxy.type", 4);>>prefs.js
echo user_pref("network.automatic-ntlm-auth.trusted-uris","site.domain.com, sites.domain.com");>>prefs.js
popd

How to get full path of a file?

This will work for both file and folder:

getAbsolutePath(){
    [[ -d $1 ]] && { cd "$1"; echo "$(pwd -P)"; } || 
    { cd "$(dirname "$1")" || exit 1; echo "$(pwd -P)/$(basename "$1")"; }
}

T-SQL split string

There is a correct version on here but I thought it would be nice to add a little fault tolerance in case they have a trailing comma as well as make it so you could use it not as a function but as part of a larger piece of code. Just in case you're only using it once time and don't need a function. This is also for integers (which is what I needed it for) so you might have to change your data types.

DECLARE @StringToSeperate VARCHAR(10)
SET @StringToSeperate = '1,2,5'

--SELECT @StringToSeperate IDs INTO #Test

DROP TABLE #IDs
CREATE TABLE #IDs (ID int) 

DECLARE @CommaSeperatedValue NVARCHAR(255) = ''
DECLARE @Position INT = LEN(@StringToSeperate)

--Add Each Value
WHILE CHARINDEX(',', @StringToSeperate) > 0
BEGIN
    SELECT @Position  = CHARINDEX(',', @StringToSeperate)  
    SELECT @CommaSeperatedValue = SUBSTRING(@StringToSeperate, 1, @Position-1)

    INSERT INTO #IDs 
    SELECT @CommaSeperatedValue

    SELECT @StringToSeperate = SUBSTRING(@StringToSeperate, @Position+1, LEN(@StringToSeperate)-@Position)

END

--Add Last Value
IF (LEN(LTRIM(RTRIM(@StringToSeperate)))>0)
BEGIN
    INSERT INTO #IDs
    SELECT SUBSTRING(@StringToSeperate, 1, @Position)
END

SELECT * FROM #IDs

@HostBinding and @HostListener: what do they do and what are they for?

Another nice thing about @HostBinding is that you can combine it with @Input if your binding relies directly on an input, eg:

@HostBinding('class.fixed-thing')
@Input()
fixed: boolean;

How to fix broken paste clipboard in VNC on Windows

You likely need to re-start VNC on both ends. i.e. when you say "restarted VNC", you probably just mean the client. But what about the other end? You likely need to re-start that end too. The root cause is likely a conflict. Many apps spy on the clipboard when they shouldn't. And many apps are not forgiving when they go to open the clipboard and can't. Robust ones will retry, others will simply not anticipate a failure and then they get fouled up and need to be restarted. Could be VNC, or it could be another app that's "listening" to the clipboard viewer chain, where it is obligated to pass along notifications to the other apps in the chain. If the notifications aren't sent, then VNC may not even know that there has been a clipboard update.

How to place div in top right hand corner of page

<style type="text/css">
 .topcorner{
  position:absolute;
  top:10;
  right:15;
  }
</style>

You ca also use this in CSS external file.

Opening a new tab to read a PDF file

Change the <a> tag like this:

<a href="newsletter_01.pdf" target="_blank">

You can find more about the target attribute here.

How to read a file line-by-line into a list?

If you want to are faced with a very large / huge file and want to read faster (imagine you are in a Topcoder/Hackerrank coding competition), you might read a considerably bigger chunk of lines into a memory buffer at one time, rather than just iterate line by line at file level.

buffersize = 2**16
with open(path) as f: 
    while True:
        lines_buffer = f.readlines(buffersize)
        if not lines_buffer:
            break
        for line in lines_buffer:
            process(line)

jQuery issue - #<an Object> has no method

Ignore me. I'm sorry everyone. I'd mistyped the url of the script. Thanks to Simon Ainley for the prod in the right direction.

Sorry again. Thanks.

How to Get the HTTP Post data in C#?

You are missing a step. You need to log / store the values on your server (mailgun is a client). Then you need to retrieve those values on your server (your pc with your web browser will be a client). These will be two totally different aspx files (or the same one with different parameters).

aspx page 1 (the one that mailgun has):

var val = Request.Form["recipient"];
var file = new File(filename);
file.write(val);
close(file);

aspx page 2:

var contents = "";
if (File.exists(filename))
  var file = File.open(filename);
  contents = file.readtoend();
  file.close()

Request.write(contents);

How do I compute derivative using Numpy?

You have four options

  1. Finite Differences
  2. Automatic Derivatives
  3. Symbolic Differentiation
  4. Compute derivatives by hand.

Finite differences require no external tools but are prone to numerical error and, if you're in a multivariate situation, can take a while.

Symbolic differentiation is ideal if your problem is simple enough. Symbolic methods are getting quite robust these days. SymPy is an excellent project for this that integrates well with NumPy. Look at the autowrap or lambdify functions or check out Jensen's blogpost about a similar question.

Automatic derivatives are very cool, aren't prone to numeric errors, but do require some additional libraries (google for this, there are a few good options). This is the most robust but also the most sophisticated/difficult to set up choice. If you're fine restricting yourself to numpy syntax then Theano might be a good choice.

Here is an example using SymPy

In [1]: from sympy import *
In [2]: import numpy as np
In [3]: x = Symbol('x')
In [4]: y = x**2 + 1
In [5]: yprime = y.diff(x)
In [6]: yprime
Out[6]: 2·x

In [7]: f = lambdify(x, yprime, 'numpy')
In [8]: f(np.ones(5))
Out[8]: [ 2.  2.  2.  2.  2.]

How to convert a private key to an RSA private key?

To Convert BEGIN OPENSSH PRIVATE KEY to BEGIN RSA PRIVATE KEY:

ssh-keygen -p -m PEM -f ~/.ssh/id_rsa

What's the difference between ViewData and ViewBag?

There are some subtle differences that mean you can use ViewData and ViewBag in slightly different ways from the view. One advantage is outlined in this post http://weblogs.asp.net/hajan/archive/2010/12/11/viewbag-dynamic-in-asp-net-mvc-3-rc-2.aspx and shows that casting can be avoided in the example by using the ViewBag instead of ViewData.

Append an object to a list in R in amortized constant time, O(1)?

If it's a list of string, just use the c() function :

R> LL <- list(a="tom", b="dick")
R> c(LL, c="harry")
$a
[1] "tom"

$b
[1] "dick"

$c
[1] "harry"

R> class(LL)
[1] "list"
R> 

That works on vectors too, so do I get the bonus points?

Edit (2015-Feb-01): This post is coming up on its fifth birthday. Some kind readers keep repeating any shortcomings with it, so by all means also see some of the comments below. One suggestion for list types:

newlist <- list(oldlist, list(someobj))

In general, R types can make it hard to have one and just one idiom for all types and uses.

How to pause a YouTube player when hiding the iframe?

A more concise, elegant, and secure answer: add “?enablejsapi=1” to the end of the video URL, then construct and stringify an ordinary object representing the pause command:

const YouTube_pause_video_command_JSON = JSON.stringify(Object.create(null, {
    "event": {
        "value": "command",
        "enumerable": true
    },
    "func": {
        "value": "pauseVideo",
        "enumerable": true
    }
}));

Use the Window.postMessage method to send the resulting JSON string to the embedded video document:

// |iframe_element| is defined elsewhere.
const video_URL = iframe_element.getAttributeNS(null, "src");
iframe_element.contentWindow.postMessage(YouTube_pause_video_command_JSON, video_URL);

Make sure you specify the video URL for the Window.postMessage method’s targetOrigin argument to ensure that your messages won’t be sent to any unintended recipient.

how to show calendar on text box click in html

You will need to use any javascript html calendar widget.

try this calendar view widget, just copy-paste some code shown in example there and thats it what you want.

Here is the link to Jquery Mobile date box - JQM datebox

Event on a disabled input

Disabled elements "eat" clicks in some browsers - they neither respond to them, nor allow them to be captured by event handlers anywhere on either the element or any of its containers.

IMHO the simplest, cleanest way to "fix" this (if you do in fact need to capture clicks on disabled elements like the OP does) is just to add the following CSS to your page:

input[disabled] {pointer-events:none}

This will make any clicks on a disabled input fall through to the parent element, where you can capture them normally. (If you have several disabled inputs, you might want to put each into an individual container of its own, if they aren't already laid out that way - an extra <span> or a <div>, say - just to make it easy to distinguish which disabled input was clicked).


The downside is that this trick unfortunately won't works for older browsers that don't support the pointer-events CSS property. (It should work from IE 11, FF v3.6, Chrome v4): caniuse.com/#search=pointer-events

If you need to support older browsers, you'll need to use one of the other answers!

Reduce size of legend area in barplot

The cex parameter will do that for you.

a <- c(3, 2, 2, 2, 1, 2 )
barplot(a, beside = T,
        col = 1:6, space = c(0, 2))
legend("topright", 
       legend = c("a", "b", "c", "d", "e", "f"), 
       fill = 1:6, ncol = 2,
       cex = 0.75)

The plot

Android Transparent TextView?

Below code for black:-

<color name="black">#000000</color>

Now if i want to use opacity than you can use below code :-

 <color name="black">#99000000</color> 

and below for opacity code:-

Hex Opacity Values

100% — FF
95% — F2
90% — E6
85% — D9
80% — CC
75% — BF
70% — B3
65% — A6
60% — 99
55% — 8C
50% — 80
45% — 73
40% — 66
35% — 59
30% — 4D
25% — 40
20% — 33
15% — 26
10% — 1A
5% — 0D
0% — 00

refer Understanding colors on Android (six characters)

React Native fixed footer

import {Dimensions} from 'react-native'

const WIDTH = Dimensions.get('window').width;
const HEIGHT = Dimensions.get('window').height;

then on the write this styles

 position: 'absolute',
 top: HEIGHT-80,
 left: 0,
 right: 0,

worked like a charm

How to get the android Path string to a file on Assets folder?

Have a look at the ReadAsset.java from API samples that come with the SDK.

       try {
        InputStream is = getAssets().open("read_asset.txt");

        // We guarantee that the available method returns the total
        // size of the asset...  of course, this does mean that a single
        // asset can't be more than 2 gigs.
        int size = is.available();

        // Read the entire asset into a local byte buffer.
        byte[] buffer = new byte[size];
        is.read(buffer);
        is.close();

        // Convert the buffer into a string.
        String text = new String(buffer);

        // Finally stick the string into the text view.
        TextView tv = (TextView)findViewById(R.id.text);
        tv.setText(text);
    } catch (IOException e) {
        // Should never happen!
        throw new RuntimeException(e);
    }

How to request Administrator access inside a batch file

I know this is not a solution for OP, but since I'm sure there are many other use cases here, I thought I would share.

I've had problems with all the code examples in these answers but then I found : http://www.robotronic.de/runasspcEn.html

It not only allows you to run as admin, it checks the file to make sure it has not been tampered with and stores the needed information securely. I'll admit it's not the most obvious tool to figure out how to use but for those of us writing code it should be simple enough.

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

Open the sql file and comment out the line that tries to create the existing database.

Want to upgrade project from Angular v5 to Angular v6

Upgrade from Angular v6 to Angular v7

Version 7 of Angular has been released Official Angular blog link. Visit official angular update guide https://update.angular.io for detailed information. These steps will work for basic angular 6 apps using Angular Material.

ng update @angular/cli 
ng update @angular/core
ng update @angular/material

Upgrade from Angular v5 to Angular v6

Version 6 of Angular has been released Official Angular blog link. I have mentioned general upgrade steps below, but before and after the update you need to make changes in your code to make it workable in v6, for that detailed information visit official website https://update.angular.io .

Upgrade Steps (largely taken from the official Angular Update Guide for a basic Angular app using Angular Material):

  1. Make sure NodeJS version is 8.9+ if not update it.

  2. Update Angular cli globally and locally, and migrate the old configuration .angular-cli.json to the new angular.json format by running the following:

    npm install -g @angular/cli  
    npm install @angular/cli  
    ng update @angular/cli
    
  3. Update all of your Angular framework packages to v6,and the correct version of RxJS and TypeScript by running the following:

    ng update @angular/core
    
  4. Update Angular Material to the latest version by running the following:

    ng update @angular/material
    
  5. RxJS v6 has major changes from v5, v6 brings backwards compatibility package rxjs-compat that will keep your applications working, but you should refactor TypeScript code so that it doesn't depend on rxjs-compat. To refactor TypeScript code run following:

    npm install -g rxjs-tslint   
    rxjs-5-to-6-migrate -p src/tsconfig.app.json
    

    Note: Once all of your dependencies have updated to RxJS 6, remove rxjs- compat as it increases bundle size. please see this RxJS Upgrade Guide for more info.

    npm uninstall rxjs-compat
    
  6. Done run ng serve to check it.
    If you get errors in build refer https://update.angular.io for detailed info.

Upgrade from Angular v5 to Angular 6.0.0-rc.5

  1. Upgrade rxjs to 6.0.0-beta.0, please see this RxJS Upgrade Guide for more info. RxJS v6 has breaking change hence first make your code compatible to latest RxJS version.

  2. Update NodeJS version to 8.9+ (this is required by angular cli 6 version)

  3. Update Angular cli global package to next version.

    npm uninstall -g @angular/cli
    npm cache verify
    

    if npm version is < 5 then use npm cache clean

    npm install -g @angular/cli@next
    
  4. Change angular packages versions in package.json file to ^6.0.0-rc.5

    "dependencies": {
      "@angular/animations": "^6.0.0-rc.5",
      "@angular/cdk": "^6.0.0-rc.12",
      "@angular/common": "^6.0.0-rc.5",
      "@angular/compiler": "^6.0.0-rc.5",
      "@angular/core": "^6.0.0-rc.5",
      "@angular/forms": "^6.0.0-rc.5",
      "@angular/http": "^6.0.0-rc.5",
      "@angular/material": "^6.0.0-rc.12",
      "@angular/platform-browser": "^6.0.0-rc.5",
      "@angular/platform-browser-dynamic": "^6.0.0-rc.5",
      "@angular/router": "^6.0.0-rc.5",
      "core-js": "^2.5.5",
      "karma-jasmine": "^1.1.1",
      "rxjs": "^6.0.0-uncanny-rc.7",
      "rxjs-compat": "^6.0.0-uncanny-rc.7",
      "zone.js": "^0.8.26"
    },
    "devDependencies": {
      "@angular-devkit/build-angular": "~0.5.0",
      "@angular/cli": "^6.0.0-rc.5",
      "@angular/compiler-cli": "^6.0.0-rc.5",
      "@types/jasmine": "2.5.38",
      "@types/node": "~8.9.4",
      "codelyzer": "~4.1.0",
      "jasmine-core": "~2.5.2",
      "jasmine-spec-reporter": "~3.2.0",
      "karma": "~1.4.1",
      "karma-chrome-launcher": "~2.0.0",
      "karma-cli": "~1.0.1",
      "karma-coverage-istanbul-reporter": "^0.2.0",
      "karma-jasmine": "~1.1.0",
      "karma-jasmine-html-reporter": "^0.2.2",
      "postcss-loader": "^2.1.4",
      "protractor": "~5.1.0",
      "ts-node": "~5.0.0",
      "tslint": "~5.9.1",
      "typescript": "^2.7.2"
    }
    
  5. Next update Angular cli local package to next version and install above mentioned packages.

    rm -rf node_modules dist # use rmdir /S/Q node_modules dist in Windows 
    Command Prompt; use rm -r -fo node_modules,dist in Windows PowerShell
    npm install --save-dev @angular/cli@next
    npm install 
    
  6. The Angular CLI configuration format has been changed from angular cli 6.0.0-rc.2 version, and your existing configuration can be updated automatically by running the following command. It will remove old config file .angular-cli.json and will write new angular.json file.

    ng update @angular/cli --migrate-only --from=1.7.4

Note :- If you get following error "The Angular Compiler requires TypeScript >=2.7.2 and <2.8.0 but 2.8.3 was found instead". run following command :

npm install [email protected]

Best way to implement multi-language/globalization in large .NET project

I'd go with the multiple resource files. It shouldn't be that hard to configure. In fact I recently answered a similar question on setting a global language based resource files in conjunction with form language resource files.

Localization in Visual Studio 2008

I would consider that the best approach at least for WinForm development.

^[A-Za-Z ][A-Za-z0-9 ]* regular expression?

This expression will check if the first letter to be alphabetic and the remaining characters to be alphanumeric or any of the following special characters: @,#,%,&,

^[A-Za-z][A-Za-z0-9@#%&\*]*$

1114 (HY000): The table is full

Unless you enabled innodb_file_per_table option, InnoDB keeps all data in one file, usually called ibdata1.

Check the size of that file and check you have enough disk space in the drive it resides on.

jQuery.inArray(), how to use it right?

The answer comes from the first paragraph of the documentation check if the results is greater than -1, not if it's true or false.

The $.inArray() method is similar to JavaScript's native .indexOf() method in that it returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0.

Because JavaScript treats 0 as loosely equal to false (i.e. 0 == false, but 0 !== false), if we're checking for the presence of value within array, we need to check if it's not equal to (or greater than) -1.

curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number

If anyone is getting this error using Nginx, try adding the following to your server config:

server {
    listen 443 ssl;
    ...
}

The issue stems from Nginx serving an HTTP server to a client expecting HTTPS on whatever port you're listening on. When you specify ssl in the listen directive, you clear this up on the server side.

How do I strip all spaces out of a string in PHP?

If you know the white space is only due to spaces, you can use:

$string = str_replace(' ','',$string); 

But if it could be due to space, tab...you can use:

$string = preg_replace('/\s+/','',$string);

Has been blocked by CORS policy: Response to preflight request doesn’t pass access control check

Angular and Django Rest Framework.

I encountered similar error while making post request to my DRF api. It happened that all I was missing was trailing slash for endpoint.

jQuery disable/enable submit button

The problem is that the change event fires only when focus is moved away from the input (e.g. someone clicks off the input or tabs out of it). Try using keyup instead:

$(document).ready(function() {
     $(':input[type="submit"]').prop('disabled', true);
     $('input[type="text"]').keyup(function() {
        if($(this).val() != '') {
           $(':input[type="submit"]').prop('disabled', false);
        }
     });
 });

SQL Server : GROUP BY clause to get comma-separated values

SELECT  [ReportId], 
        SUBSTRING(d.EmailList,1, LEN(d.EmailList) - 1) EmailList
FROM
        (
            SELECT DISTINCT [ReportId]
            FROM Table1
        ) a
        CROSS APPLY
        (
            SELECT [Email] + ', ' 
            FROM Table1 AS B 
            WHERE A.[ReportId] = B.[ReportId]
            FOR XML PATH('')
        ) D (EmailList) 

SQLFiddle Demo

Firing a Keyboard Event in Safari, using JavaScript

This is due to a bug in Webkit.

You can work around the Webkit bug using createEvent('Event') rather than createEvent('KeyboardEvent'), and then assigning the keyCode property. See this answer and this example.

Comparing two byte arrays in .NET

 using System.Linq; //SequenceEqual

 byte[] ByteArray1 = null;
 byte[] ByteArray2 = null;

 ByteArray1 = MyFunct1();
 ByteArray2 = MyFunct2();

 if (ByteArray1.SequenceEqual<byte>(ByteArray2) == true)
 {
    MessageBox.Show("Match");
 }
 else
 {
   MessageBox.Show("Don't match");
 }

Git error on git pull (unable to update local ref)

My team and I ran into this error, unable to update local ref, when doing a pull in SourceTree.

Update 2020: Per @Edward Yang's answer below, @bryan's comment on this answer, and this question/answer you may need to run both git gc --prune=now and git remote prune origin. Running only the former has always worked for me but based on ppl's responses I think both are necessary to address different causes of the error.

We used:

git gc --prune=now

This removes any duplicate reference objects which should fix the issue.

Here are a few links where you can learn more about git references and pruning :

git tip of the week

git-prune documentation

git references

java.lang.UnsupportedClassVersionError: Unsupported major.minor version 51.0 (unable to load class frontend.listener.StartupListener)

What is your output when you do java -version? This will tell you what version the running JVM is.

The Unsupported major.minor version 51.0 error could mean:

  • Your server is running a lower Java version then the one used to compile your Servlet and vice versa

Either way, uninstall all JVM runtimes including JDK and download latest and re-install. That should fix any Unsupported major.minor error as you will have the lastest JRE and JDK (Maybe even newer then the one used to compile the Servlet)

See: http://www.java.com/en/download/manual.jsp (7 Update 25 )

and here: http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform (JDK) 7u25)

for the latest version of the JRE and JDK respectively.

EDIT:

Most likely your code was written in Java7 however maybe it was done using Java7update4 and your system is running Java7update3. Thus they both are effectively the same major version but the minor versions differ. Only the larger minor version is backward compatible with the lower minor version.

Edit 2 : If you have more than one jdk installed on your pc. you should check that Apache Tomcat is using the same one (jre) you are compiling your programs with. If you installed a new jdk after installing apache it normally won't select the new version.

Change HTML email body font type and size in VBA

FYI I did a little research as well and if the name of the font-family you want to apply contains spaces (as an example I take Gill Alt One MT Light), you should write it this way :

strbody= "<BODY style=" & Chr(34) & "font-family:Gill Alt One MT Light" & Chr(34) & ">" & YOUR_TEXT & "</BODY>"

HTTP 415 unsupported media type error when calling Web API 2 endpoint

I experienced this issue when calling my web api endpoint and solved it.

In my case it was an issue in the way the client was encoding the body content. I was not specifying the encoding or media type. Specifying them solved it.

Not specifying encoding type, caused 415 error:

var content = new StringContent(postData);
httpClient.PostAsync(uri, content);

Specifying the encoding and media type, success:

var content = new StringContent(postData, Encoding.UTF8, "application/json");
httpClient.PostAsync(uri, content);

Convert from lowercase to uppercase all values in all character variables in dataframe

Alternatively, if you just want to convert one particular row to uppercase, use the code below:

df[[1]] <- toupper(df[[1]])

File Permissions and CHMOD: How to set 777 in PHP upon file creation?

PHP has a built in function called bool chmod(string $filename, int $mode )

http://php.net/function.chmod

private function writeFileContent($file, $content){
    $fp = fopen($file, 'w');
    fwrite($fp, $content);
    fclose($fp);
    chmod($file, 0777);  //changed to add the zero
    return true;
}

Box shadow for bottom side only

-webkit-box-shadow: 0 3px 5px -3px #000;
-moz-box-shadow: 0 3px 5px -3px #000;
box-shadow: 0 3px 5px -3px #000;

WARNING: sanitizing unsafe style value url

If background image with linear-gradient (*ngFor)

View:

<div [style.background-image]="getBackground(trendingEntity.img)" class="trending-content">
</div>

Class:

import { DomSanitizer, SafeResourceUrl, SafeUrl } from '@angular/platform-browser';

constructor(private _sanitizer: DomSanitizer) {}

getBackground(image) {
    return this._sanitizer.bypassSecurityTrustStyle(`linear-gradient(rgba(29, 29, 29, 0), rgba(16, 16, 23, 0.5)), url(${image})`);
}

Division in Python 2.7. and 3.3

"/" is integer division in python 2 so it is going to round to a whole number. If you would like a decimal returned, just change the type of one of the inputs to float:

float(20)/15 #1.33333333

Python Hexadecimal

Use the format() function with a '02x' format.

>>> format(255, '02x')
'ff'
>>> format(2, '02x')
'02'

The 02 part tells format() to use at least 2 digits and to use zeros to pad it to length, x means lower-case hexadecimal.

The Format Specification Mini Language also gives you X for uppercase hex output, and you can prefix the field width with # to include a 0x or 0X prefix (depending on wether you used x or X as the formatter). Just take into account that you need to adjust the field width to allow for those extra 2 characters:

>>> format(255, '02X')
'FF'
>>> format(255, '#04x')
'0xff'
>>> format(255, '#04X')
'0XFF'

Port 443 in use by "Unable to open process" with PID 4

Some process is using this port, so you can change the port that is used by xampp, to be able to use it. For this job you have to do this:

1- Open httpd-ssl.conf in xampp\apache\conf\extra

2- Look for the line containing Listen 443

3- Change port number to anything you want. I use 4430. ex. Listen 4430.

4- Replace every 443 strings in that file with 4430.

5- Save the file.

When should static_cast, dynamic_cast, const_cast and reinterpret_cast be used?

While other answers nicely described all differences between C++ casts, I would like to add a short note why you should not use C-style casts (Type) var and Type(var).

For C++ beginners C-style casts look like being the superset operation over C++ casts (static_cast<>(), dynamic_cast<>(), const_cast<>(), reinterpret_cast<>()) and someone could prefer them over the C++ casts. In fact C-style cast is the superset and shorter to write.

The main problem of C-style casts is that they hide developer real intention of the cast. The C-style casts can do virtually all types of casting from normally safe casts done by static_cast<>() and dynamic_cast<>() to potentially dangerous casts like const_cast<>(), where const modifier can be removed so the const variables can be modified and reinterpret_cast<>() that can even reinterpret integer values to pointers.

Here is the sample.

int a=rand(); // Random number.

int* pa1=reinterpret_cast<int*>(a); // OK. Here developer clearly expressed he wanted to do this potentially dangerous operation.

int* pa2=static_cast<int*>(a); // Compiler error.
int* pa3=dynamic_cast<int*>(a); // Compiler error.

int* pa4=(int*) a; // OK. C-style cast can do such cast. The question is if it was intentional or developer just did some typo.

*pa4=5; // Program crashes.

The main reason why C++ casts were added to the language was to allow a developer to clarify his intentions - why he is going to do that cast. By using C-style casts which are perfectly valid in C++ you are making your code less readable and more error prone especially for other developers who didn't create your code. So to make your code more readable and explicit you should always prefer C++ casts over C-style casts.

Here is a short quote from Bjarne Stroustrup's (the author of C++) book The C++ Programming Language 4th edition - page 302.

This C-style cast is far more dangerous than the named conversion operators because the notation is harder to spot in a large program and the kind of conversion intended by the programmer is not explicit.

What is middleware exactly?

I always thought of it as the oldest software I have had to install. The total app used a web server, a database server, and an application server. The web server being the middleware between the data and the app.

When to use CouchDB over MongoDB and vice versa

Of C, A & P (Consistency, Availability & Partition tolerance) which 2 are more important to you? Quick reference, the Visual Guide To NoSQL Systems

  • MongodB : Consistency and Partition Tolerance
  • CouchDB : Availability and Partition Tolerance

A blog post, Cassandra vs MongoDB vs CouchDB vs Redis vs Riak vs HBase vs Membase vs Neo4j comparison has 'Best used' scenarios for each NoSQL database compared. Quoting the link,

  • MongoDB: If you need dynamic queries. If you prefer to define indexes, not map/reduce functions. If you need good performance on a big DB. If you wanted CouchDB, but your data changes too much, filling up disks.
  • CouchDB : For accumulating, occasionally changing data, on which pre-defined queries are to be run. Places where versioning is important.

A recent (Feb 2012) and more comprehensive comparison by Riyad Kalla,

  • MongoDB : Master-Slave Replication ONLY
  • CouchDB : Master-Master Replication

A blog post (Oct 2011) by someone who tried both, A MongoDB Guy Learns CouchDB commented on the CouchDB's paging being not as useful.

A dated (Jun 2009) benchmark by Kristina Chodorow (part of team behind MongoDB),

I'd go for MongoDB.

Hope it helps.

Why can't I reference System.ComponentModel.DataAnnotations?

For .Net Core in Visual Studio 2019 try this. see VS suggestion

It worked for me, hope it'll work for you as well.

ConnectionTimeout versus SocketTimeout

A connection timeout occurs only upon starting the TCP connection. This usually happens if the remote machine does not answer. This means that the server has been shut down, you used the wrong IP/DNS name, wrong port or the network connection to the server is down.

A socket timeout is dedicated to monitor the continuous incoming data flow. If the data flow is interrupted for the specified timeout the connection is regarded as stalled/broken. Of course this only works with connections where data is received all the time.

By setting socket timeout to 1 this would require that every millisecond new data is received (assuming that you read the data block wise and the block is large enough)!

If only the incoming stream stalls for more than a millisecond you are running into a timeout.

Compiling php with curl, where is curl installed?

If you're going to compile a 64bit version(x86_64) of php use: /usr/lib64/

For architectures (i386 ... i686) use /usr/lib/

I recommend compiling php to the same architecture as apache. As you're using a 64bit linux i asume your apache is also compiled for x86_64.

How do you create different variable names while in a loop?

Sure you can; it's called a dictionary:

d = {}
for x in range(1, 10):
    d["string{0}".format(x)] = "Hello"
>>> d["string5"]
'Hello'
>>> d
{'string1': 'Hello',
 'string2': 'Hello',
 'string3': 'Hello',
 'string4': 'Hello',
 'string5': 'Hello',
 'string6': 'Hello',
 'string7': 'Hello',
 'string8': 'Hello',
 'string9': 'Hello'}

I said this somewhat tongue in check, but really the best way to associate one value with another value is a dictionary. That is what it was designed for!

PHP compare two arrays and get the matched values not the difference

Simple, use array_intersect() instead:

$result = array_intersect($array1, $array2);

jQuery Ajax File Upload

<html>
    <head>
        <title>Ajax file upload</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
        <script>
            $(document).ready(function (e) {
            $("#uploadimage").on('submit', (function(e) {
            e.preventDefault();
                    $.ajax({
                    url: "upload.php", // Url to which the request is send
                            type: "POST", // Type of request to be send, called as method
                            data: new FormData(this), // Data sent to server, a set of key/value pairs (i.e. form fields and values)
                            contentType: false, // The content type used when sending data to the server.
                            cache: false, // To unable request pages to be cached
                            processData:false, // To send DOMDocument or non processed data file it is set to false
                            success: function(data)   // A function to be called if request succeeds
                            {
                            alert(data);
                            }
                    });
            }));
        </script>
    </head>
    <body>
        <div class="main">
            <h1>Ajax Image Upload</h1><br/>
            <hr>
            <form id="uploadimage" action="" method="post" enctype="multipart/form-data">
                <div id="image_preview"><img id="previewing" src="noimage.png" /></div>
                <hr id="line">
                <div id="selectImage">
                    <label>Select Your Image</label><br/>
                    <input type="file" name="file" id="file" required />
                    <input type="submit" value="Upload" class="submit" />
                </div>
            </form>
        </div>
    </body>
</html>

Ruby capitalize every word first letter

try this:

puts 'one TWO three foUR'.split.map(&:capitalize).join(' ')

#=> One Two Three Four

or

puts 'one TWO three foUR'.split.map(&:capitalize)*' '

How do I check in python if an element of a list is empty?

Unlike in some laguages, empty is not a keyword in Python. Python lists are constructed form the ground up, so if element i has a value, then element i-1 has a value, for all i > 0.

To do an equality check, you usually use either the == comparison operator.

>>> my_list = ["asdf", 0, 42, '', None, True, "LOLOL"]
>>> my_list[0] == "asdf"
True
>>> my_list[4] is None
True
>>> my_list[2] == "the universe"
False
>>> my_list[3]
""
>>> my_list[3] == ""
True

Here's a link to the strip method: your comment indicates to me that you may have some strange file parsing error going on, so make sure you're stripping off newlines and extraneous whitespace before you expect an empty line.

Recommended website resolution (width and height)?

there are actually industry standards for widths (well according to yahoo at least). Their supported widths are 750, 950, 974, 100%

There are advantages of these widths for their predefined grids (column layouts) which work well with standard dimensions for advertisements if you were to include any.

Interesting talk too worth watching.

see YUI Base

Missing Microsoft RDLC Report Designer in Visual Studio

I had the same problem, after install the MS VS Community 2015, I didn't find the RDLC files neither the Report Viewer component, I solve the problem by going in the Control Panel (Windows) -> Programs -> Try to uninstall the MS VS Community and choose MODIFY, in this moment you will be able to Check the Microsoft SQL Server Data Tools.

That is it!

How to create cron job using PHP?

Type the following in the linux/ubuntu terminal

 crontab -e 

select an editor (sometime it asks for the editor) and this to run for every minute

*       *       *       *       *       /usr/bin/php path/to/cron.php &> /dev/null

Corrupt jar file

It can be something so silly as you are transferring the file via FTP to a target machine, you go and run the .JAR file but this was so big that it has not yet been finished transferred :) Yes it happened to me..

How do you convert an entire directory with ffmpeg?

For Windows:

Here I'm Converting all the (.mp4) files to (.mp3) files.
Just open cmd, goto the desired folder and type the command.

Shortcut: (optional)
1. Goto the folder where your (.mp4) files are present
2. Press Shift and Left click and Choose "Open PowerShell Window Here"
or "Open Command Prompt Window Here"
3. Type "cmd" [NOTE: Skip this step if it directly opens cmd instead of PowerShell]
4. Run the command

for %i in (*.mp4) do ffmpeg -i "%i" "%~ni.mp3"

If you want to put this into a batch file on Windows 10, you need to use %%i.

What is [Serializable] and when should I use it?

Here is short example of how serialization works. I was also learning about the same and I found two links useful. What Serialization is and how it can be done in .NET.

A sample program explaining serialization

If you don't understand the above program a much simple program with explanation is given here.

jQuery deferreds and promises - .then() vs .done()

.done() terminates the promise chain, making sure nothing else can attach further steps. This means that the jQuery promise implementation can throw any unhandled exception, since no one can possible handle it using .fail().

In practical terms, if you do not plan to attach more steps to a promise, you should use .done(). For more details see why promises need to be done

How to insert element into arrays at specific position?

Simplest solution, if you want to insert (an element or array) after a certain key:

function array_splice_after_key($array, $key, $array_to_insert)
{
    $key_pos = array_search($key, array_keys($array));
    if($key_pos !== false){
        $key_pos++;
        $second_array = array_splice($array, $key_pos);
        $array = array_merge($array, $array_to_insert, $second_array);
    }
    return $array;
}

So, if you have:

$array = [
    'one' => 1,
    'three' => 3
];
$array_to_insert = ['two' => 2];

And execute:

$result_array = array_splice_after_key($array, 'one', $array_to_insert);

You'll have:

Array ( 
    ['one'] => 1 
    ['two'] => 2 
    ['three'] => 3 
)

How to set HTTP headers (for cache-control)?

To use cache-control in HTML, you use the meta tag, e.g.

<meta http-equiv="Cache-control" content="public">

The value in the content field is defined as one of the four values below.

Some information on the Cache-Control header is as follows

HTTP 1.1. Allowed values = PUBLIC | PRIVATE | NO-CACHE | NO-STORE.

Public - may be cached in public shared caches.
Private - may only be cached in private cache.
No-Cache - may not be cached.
No-Store - may be cached but not archived.

The directive CACHE-CONTROL:NO-CACHE indicates cached information should not be used and instead requests should be forwarded to the origin server. This directive has the same semantics as the PRAGMA:NO-CACHE.

Clients SHOULD include both PRAGMA: NO-CACHE and CACHE-CONTROL: NO-CACHE when a no-cache request is sent to a server not known to be HTTP/1.1 compliant. Also see EXPIRES.

Note: It may be better to specify cache commands in HTTP than in META statements, where they can influence more than the browser, but proxies and other intermediaries that may cache information.

Swift convert unix time to date and time

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

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

Excel "External table is not in the expected format."

I have also seen this error when trying to use complex INDIRECT() formulas on the sheet that is being imported. I noticed this because this was the only difference between two workbooks where one was importing and the other wasn't. Both were 2007+ .XLSX files, and the 12.0 engine was installed.

I confirmed this was the issue by:

  • Making a copy of the file (still had the issue, so it wasn't some save-as difference)
  • Selecting all cells in the sheet with the Indirect formulas
  • Pasting as Values only

and the error disappeared.

How do I install Keras and Theano in Anaconda Python on Windows?

It is my solution for the same problem

  • Install TDM GCC x64.
  • Install Anaconda x64.
  • Open the Anaconda prompt
  • Run conda update conda
  • Run conda update --all
  • Run conda install mingw libpython
  • Install the latest version of Theano, pip install git+git://github.com/Theano/Theano.git
  • Run pip install git+git://github.com/fchollet/keras.git

Alternate output format for psql

You have so many choices, how could you be confused :-)? The main controls are:

# \pset format
# \H
# \x
# \pset pager off

Each has options and interactions with the others. The most automatic options are:

# \x off;\pset format wrapped
# \x auto

The newer "\x auto" option switches to line-by-line display only "if needed".

-[ RECORD 1 ]---------------
id          | 6
description | This is a gallery of oilve oil brands.
authority   | I love olive oil, and wanted to create a place for
reviews and comments on various types.
-[ RECORD 2 ]---------------
id          | 19
description | XXX Test A 
authority   | Testing

The older "\pset format wrapped" is similar in that it tries to fit the data neatly on screen, but falls back to unaligned if the headers won't fit. Here's an example of wrapped:

 id |          description           |            authority            
----+--------------------------------+---------------------------------
  6 | This is a gallery of oilve     | I love olive oil, and wanted to
    ; oil brands.                    ;  create a place for reviews and
    ;                                ;  comments on various types.
 19 | Test Test A                    | Testing

Why plt.imshow() doesn't display the image?

If you want to print the picture using imshow() you also execute plt.show()

How to vertically align a html radio button to it's label?

I know I'd selected the anwer by menuka devinda but looking at the comments below it I concurred and tried to come up with a better solution. I managed to come up with this and in my opinion it's a much more elegant solution:

input[type='radio'], label{   
    vertical-align: baseline;
    padding: 10px;
    margin: 10px;
 }

Thanks to everyone who offered an answer, your answer didn't go unnoticed. If you still got any other ideas feel free to add your own answer to this question.

Python - A keyboard command to stop infinite loop?

Ctrl+C is what you need. If it didn't work, hit it harder. :-) Of course, you can also just close the shell window.

Edit: You didn't mention the circumstances. As a last resort, you could write a batch file that contains taskkill /im python.exe, and put it on your desktop, Start menu, etc. and run it when you need to kill a runaway script. Of course, it will kill all Python processes, so be careful.

support FragmentPagerAdapter holds reference to old fragments

Since the FragmentManager will take care of restoring your Fragments for you as soon as the onResume() method is called I have the fragment call out to the activity and add itself to a list. In my instance I am storing all of this in my PagerAdapter implementation. Each fragment knows it's position because it is added to the fragment arguments on creation. Now whenever I need to manipulate a fragment at a specific index all I have to do is use the list from my adapter.

The following is an example of an Adapter for a custom ViewPager that will grow the fragment as it moves into focus, and scale it down as it moves out of focus. Besides the Adapter and Fragment classes I have here all you need is for the parent activity to be able to reference the adapter variable and you are set.

Adapter

public class GrowPagerAdapter extends FragmentPagerAdapter implements OnPageChangeListener, OnScrollChangedListener {

public final String TAG = this.getClass().getSimpleName();

private final int COUNT = 4;

public static final float BASE_SIZE = 0.8f;
public static final float BASE_ALPHA = 0.8f;

private int mCurrentPage = 0;
private boolean mScrollingLeft;

private List<SummaryTabletFragment> mFragments;

public int getCurrentPage() {
    return mCurrentPage;
}

public void addFragment(SummaryTabletFragment fragment) {
    mFragments.add(fragment.getPosition(), fragment);
}

public GrowPagerAdapter(FragmentManager fm) {
    super(fm);

    mFragments = new ArrayList<SummaryTabletFragment>();
}

@Override
public int getCount() {
    return COUNT;
}

@Override
public Fragment getItem(int position) {
    return SummaryTabletFragment.newInstance(position);
}

@Override
public void onPageScrollStateChanged(int state) {}

@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    adjustSize(position, positionOffset);
}

@Override
public void onPageSelected(int position) {
    mCurrentPage = position;
}

/**
 * Used to adjust the size of each view in the viewpager as the user
 * scrolls.  This provides the effect of children scaling down as they
 * are moved out and back to full size as they come into focus.
 * 
 * @param position
 * @param percent
 */
private void adjustSize(int position, float percent) {

    position += (mScrollingLeft ? 1 : 0);
    int secondary = position + (mScrollingLeft ? -1 : 1);
    int tertiary = position + (mScrollingLeft ? 1 : -1);

    float scaleUp = mScrollingLeft ? percent : 1.0f - percent;
    float scaleDown = mScrollingLeft ? 1.0f - percent : percent;

    float percentOut = scaleUp > BASE_ALPHA ? BASE_ALPHA : scaleUp;
    float percentIn = scaleDown > BASE_ALPHA ? BASE_ALPHA : scaleDown;

    if (scaleUp < BASE_SIZE)
        scaleUp = BASE_SIZE;

    if (scaleDown < BASE_SIZE)
        scaleDown = BASE_SIZE;

    // Adjust the fragments that are, or will be, on screen
    SummaryTabletFragment current = (position < mFragments.size()) ? mFragments.get(position) : null;
    SummaryTabletFragment next = (secondary < mFragments.size() && secondary > -1) ? mFragments.get(secondary) : null;
    SummaryTabletFragment afterNext = (tertiary < mFragments.size() && tertiary > -1) ? mFragments.get(tertiary) : null;

    if (current != null && next != null) {

        // Apply the adjustments to each fragment
        current.transitionFragment(percentIn, scaleUp);
        next.transitionFragment(percentOut, scaleDown);

        if (afterNext != null) {
            afterNext.transitionFragment(BASE_ALPHA, BASE_SIZE);
        }
    }
}

@Override
public void onScrollChanged(int l, int t, int oldl, int oldt) {

    // Keep track of which direction we are scrolling
    mScrollingLeft = (oldl - l) < 0;
}
}

Fragment

public class SummaryTabletFragment extends BaseTabletFragment {

public final String TAG = this.getClass().getSimpleName();

private final float SCALE_SIZE = 0.8f;

private RelativeLayout mBackground, mCover;
private TextView mTitle;
private VerticalTextView mLeft, mRight;

private String mTitleText;
private Integer mColor;

private boolean mInit = false;
private Float mScale, mPercent;

private GrowPagerAdapter mAdapter;
private int mCurrentPosition = 0;

public String getTitleText() {
    return mTitleText;
}

public void setTitleText(String titleText) {
    this.mTitleText = titleText;
}

public static SummaryTabletFragment newInstance(int position) {

    SummaryTabletFragment fragment = new SummaryTabletFragment();
    fragment.setRetainInstance(true);

    Bundle args = new Bundle();
    args.putInt("position", position);
    fragment.setArguments(args);

    return fragment;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    super.onCreateView(inflater, container, savedInstanceState);

    mRoot = inflater.inflate(R.layout.tablet_dummy_view, null);

    setupViews();
    configureView();

    return mRoot;
}

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

    if (savedInstanceState != null) {
        mColor = savedInstanceState.getInt("color", Color.BLACK);
    }

    configureView();
}

@Override
public void onSaveInstanceState(Bundle outState)  {

    outState.putInt("color", mColor);

    super.onSaveInstanceState(outState);
}

@Override
public int getPosition() {
    return getArguments().getInt("position", -1);
}

@Override
public void setPosition(int position) {
    getArguments().putInt("position", position);
}

public void onResume() {
    super.onResume();

    mAdapter = mActivity.getPagerAdapter();
    mAdapter.addFragment(this);
    mCurrentPosition = mAdapter.getCurrentPage();

    if ((getPosition() == (mCurrentPosition + 1) || getPosition() == (mCurrentPosition - 1)) && !mInit) {
        mInit = true;
        transitionFragment(GrowPagerAdapter.BASE_ALPHA, GrowPagerAdapter.BASE_SIZE);
        return;
    }

    if (getPosition() == mCurrentPosition && !mInit) {
        mInit = true;
        transitionFragment(0.00f, 1.0f);
    }
}

private void setupViews() {

    mCover = (RelativeLayout) mRoot.findViewById(R.id.cover);
    mLeft = (VerticalTextView) mRoot.findViewById(R.id.title_left);
    mRight = (VerticalTextView) mRoot.findViewById(R.id.title_right);
    mBackground = (RelativeLayout) mRoot.findViewById(R.id.root);
    mTitle = (TextView) mRoot.findViewById(R.id.title);
}

private void configureView() {

    Fonts.applyPrimaryBoldFont(mLeft, 15);
    Fonts.applyPrimaryBoldFont(mRight, 15);

    float[] size = UiUtils.getScreenMeasurements(mActivity);
    int width = (int) (size[0] * SCALE_SIZE);
    int height = (int) (size[1] * SCALE_SIZE);

    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(width, height);
    mBackground.setLayoutParams(params);

    if (mScale != null)
        transitionFragment(mPercent, mScale);

    setRandomBackground();

    setTitleText("Fragment " + getPosition());

    mTitle.setText(getTitleText().toUpperCase());
    mLeft.setText(getTitleText().toUpperCase());
    mRight.setText(getTitleText().toUpperCase());

    mLeft.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            mActivity.showNextPage();
        }
    });

    mRight.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            mActivity.showPrevPage();
        }
    });
}

private void setRandomBackground() {

    if (mColor == null) {
        Random r = new Random();
        mColor = Color.rgb(r.nextInt(255), r.nextInt(255), r.nextInt(255));
    }

    mBackground.setBackgroundColor(mColor);
}

public void transitionFragment(float percent, float scale) {

    this.mScale = scale;
    this.mPercent = percent;

    if (getView() != null && mCover != null) {

        getView().setScaleX(scale);
        getView().setScaleY(scale);

        mCover.setAlpha(percent);
        mCover.setVisibility((percent <= 0.05f) ? View.GONE : View.VISIBLE);
    }
}

@Override
public String getFragmentTitle() {
    return null;
}
}

How do I assert an Iterable contains elements with a certain property?

AssertJ provides an excellent feature in extracting() : you can pass Functions to extract fields. It provides a check at compile time.
You could also assert the size first easily.

It would give :

import static org.assertj.core.api.Assertions;

Assertions.assertThat(myClass.getMyItems())
          .hasSize(2)
          .extracting(MyItem::getName)
          .containsExactlyInAnyOrder("foo", "bar"); 

containsExactlyInAnyOrder() asserts that the list contains only these values whatever the order.

To assert that the list contains these values whatever the order but may also contain other values use contains() :

.contains("foo", "bar"); 

As a side note : to assert multiple fields from elements of a List , with AssertJ we do that by wrapping expected values for each element into a tuple() function :

import static org.assertj.core.api.Assertions;
import static org.assertj.core.groups.Tuple;

Assertions.assertThat(myClass.getMyItems())
          .hasSize(2)
          .extracting(MyItem::getName, MyItem::getOtherValue)
          .containsExactlyInAnyOrder(
               tuple("foo", "OtherValueFoo"),
               tuple("bar", "OtherValueBar")
           ); 

What svn command would list all the files modified on a branch?

This will do it I think:

svn diff -r 22334:HEAD --summarize <url of the branch>

Receiving JSON data back from HTTP request

Install this nuget package from Microsoft System.Net.Http.Json. It contains extension methods.

Then add using System.Net.Http.Json

Now, you'll be able to see these methods:

enter image description here

So you can now do this:

await httpClient.GetFromJsonAsync<IList<WeatherForecast>>("weatherforecast");

Source: https://www.stevejgordon.co.uk/sending-and-receiving-json-using-httpclient-with-system-net-http-json

Count number of 1's in binary representation

I've got a solution that counts the bits in O(Number of 1's) time:

bitcount(n):
    count = 0
    while n > 0:
        count = count + 1
        n = n & (n-1)
    return count

In worst case (when the number is 2^n - 1, all 1's in binary) it will check every bit.

Edit: Just found a very nice constant-time, constant memory algorithm for bitcount. Here it is, written in C:

int BitCount(unsigned int u)
{
     unsigned int uCount;

     uCount = u - ((u >> 1) & 033333333333) - ((u >> 2) & 011111111111);
     return ((uCount + (uCount >> 3)) & 030707070707) % 63;
}

You can find proof of its correctness here.

Why is sed not recognizing \t as a tab?

@sedit was on the right path, but it's a bit awkward to define a variable.

Solution (bash specific)

The way to do this in bash is to put a dollar sign in front of your single quoted string.

$ echo -e '1\n2\n3'
1
2
3

$ echo -e '1\n2\n3' | sed 's/.*/\t&/g'
t1
t2
t3

$ echo -e '1\n2\n3' | sed $'s/.*/\t&/g'
    1
    2
    3

If your string needs to include variable expansion, you can put quoted strings together like so:

$ timestamp=$(date +%s)
$ echo -e '1\n2\n3' | sed "s/.*/$timestamp"$'\t&/g'
1491237958  1
1491237958  2
1491237958  3

Explanation

In bash $'string' causes "ANSI-C expansion". And that is what most of us expect when we use things like \t, \r, \n, etc. From: https://www.gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.html#ANSI_002dC-Quoting

Words of the form $'string' are treated specially. The word expands to string, with backslash-escaped characters replaced as specified by the ANSI C standard. Backslash escape sequences, if present, are decoded...

The expanded result is single-quoted, as if the dollar sign had not been present.

Solution (if you must avoid bash)

I personally think most efforts to avoid bash are silly because avoiding bashisms does NOT* make your code portable. (Your code will be less brittle if you shebang it to bash -eu than if you try to avoid bash and use sh [unless you are an absolute POSIX ninja].) But rather than have a religious argument about that, I'll just give you the BEST* answer.

$ echo -e '1\n2\n3' | sed "s/.*/$(printf '\t')&/g"
    1
    2
    3

* BEST answer? Yes, because one example of what most anti-bash shell scripters would do wrong in their code is use echo '\t' as in @robrecord's answer. That will work for GNU echo, but not BSD echo. That is explained by The Open Group at http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html#tag_20_37_16 And this is an example of why trying to avoid bashisms usually fail.

Best way to get identity of inserted row?

After Your Insert Statement you need to add this. And Make sure about the table name where data is inserting.You will get current row no where row affected just now by your insert statement.

IDENT_CURRENT('tableName')

How to find integer array size in java

There is no method call size() with array. you can use array.length

What's the difference between xsd:include and xsd:import?

Use xsd:include brings all declarations and definitions of an external schema document into the current schema.

Use xsd:import to bring in an XSD from a different namespace and used to build a new schema by extending existing schema documents..

How to generate java classes from WSDL file

I have quite complex WCF web service and I've tried a few different tools, but in most cases I couldn't connect to my web service. Finally I've used this one:

http://easywsdl.com/

This is only one tool which generetes classes that works without ANY changes!

How to get the request parameters in Symfony 2?

$request = Request::createFromGlobals();
$getParameter = $request->get('getParameter');

MongoDB: Combine data from multiple collections into one..how?

You've to do that in your application layer. If you're using an ORM, it could use annotations (or something similar) to pull references that exist in other collections. I only have worked with Morphia, and the @Reference annotation fetches the referenced entity when queried, so I am able to avoid doing it myself in the code.

belongs_to through associations

It sounds like what you want is a User who has many Questions.
The Question has many Answers, one of which is the User's Choice.

Is this what you are after?

I would model something like that along these lines:

class User
  has_many :questions
end

class Question
  belongs_to :user
  has_many   :answers
  has_one    :choice, :class_name => "Answer"

  validates_inclusion_of :choice, :in => lambda { answers }
end

class Answer
  belongs_to :question
end

Returning a value from thread?

If you don't want to use a BackgroundWorker, and just use a regular Thread, then you can fire an event to return data like this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace ThreadWithDataReturnExample
{
    public partial class Form1 : Form
    {
        private Thread thread1 = null;

        public Form1()
        {
            InitializeComponent();

            thread1 = new Thread(new ThreadStart(this.threadEntryPoint));
            Thread1Completed += new AsyncCompletedEventHandler(thread1_Thread1Completed);
        }

        private void startButton_Click(object sender, EventArgs e)
        {
            thread1.Start();
            //Alternatively, you could pass some object
            //in such as Start(someObject);
            //With apprioriate locking, or protocol where
            //no other threads access the object until
            //an event signals when the thread is complete,
            //any other class with a reference to the object 
            //would be able to access that data.
            //But instead, I'm going to use AsyncCompletedEventArgs 
            //in an event that signals completion
        }

        void thread1_Thread1Completed(object sender, AsyncCompletedEventArgs e)
        {
            if (this.InvokeRequired)
            {//marshal the call if we are not on the GUI thread                
                BeginInvoke(new AsyncCompletedEventHandler(thread1_Thread1Completed),
                  new object[] { sender, e });
            }
            else
            {
                //display error if error occurred
                //if no error occurred, process data
                if (e.Error == null)
                {//then success

                    MessageBox.Show("Worker thread completed successfully");
                    DataYouWantToReturn someData = e.UserState as DataYouWantToReturn;
                    MessageBox.Show("Your data my lord: " + someData.someProperty);

                }
                else//error
                {
                    MessageBox.Show("The following error occurred:" + Environment.NewLine + e.Error.ToString());
                }
            }
        }

        #region I would actually move all of this into it's own class
            private void threadEntryPoint()
            {
                //do a bunch of stuff

                //when you are done:
                //initialize object with data that you want to return
                DataYouWantToReturn dataYouWantToReturn = new DataYouWantToReturn();
                dataYouWantToReturn.someProperty = "more data";

                //signal completion by firing an event
                OnThread1Completed(new AsyncCompletedEventArgs(null, false, dataYouWantToReturn));
            }

            /// <summary>
            /// Occurs when processing has finished or an error occurred.
            /// </summary>
            public event AsyncCompletedEventHandler Thread1Completed;
            protected virtual void OnThread1Completed(AsyncCompletedEventArgs e)
            {
                //copy locally
                AsyncCompletedEventHandler handler = Thread1Completed;
                if (handler != null)
                {
                    handler(this, e);
                }
            }
        #endregion

    }
}

How to make type="number" to positive numbers only

Add a min attribute

_x000D_
_x000D_
<input type="number" min="0">
_x000D_
_x000D_
_x000D_

Form inline inside a form horizontal in twitter bootstrap?

to make it simple, just add a class="form-inline" before the input.

example:

<div class="col-md-4 form-inline"> //add the class here...
     <label>Lot Size:</label>
     <input type="text" value="" name="" class="form-control" >
 </div>

How to delete multiple values from a vector?

UPDATE:

All of the above answers won't work for the repeated values, @BenBolker's answer using duplicated() predicate solves this:

full_vector[!full_vector %in% searched_vector | duplicated(full_vector)]

Original Answer: here I write a little function for this:

exclude_val<-function(full_vector,searched_vector){

      found=c()

      for(i in full_vector){  

        if(any(is.element(searched_vector,i))){
          searched_vector[(which(searched_vector==i))[1]]=NA
        }
        else{
          found=c(found,i)
        }
    }

    return(found)
}

so, let's say full_vector=c(1,2,3,4,1) and searched_vector=c(1,2,3).

exclude_val(full_vector,searched_vector) will return (4,1), however above answers will return just (4).

How to make space between LinearLayout children?

You should android:layout_margin<Side> on the children. Padding is internal.

setSupportActionBar toolbar cannot be applied to (android.widget.Toolbar) error

For Android version above 3:

import androidx.appcompat.widget.Toolbar;

For Android version below 3:

import android.widget.Toolbar;

Install NuGet via PowerShell script

Here's a short PowerShell script to do what you probably expect:

$sourceNugetExe = "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe"
$targetNugetExe = "$rootPath\nuget.exe"
Invoke-WebRequest $sourceNugetExe -OutFile $targetNugetExe
Set-Alias nuget $targetNugetExe -Scope Global -Verbose

Note that Invoke-WebRequest cmdlet arrived with PowerShell v3.0. This article gives the idea.

OpenCV resize fails on large image with "error: (-215) ssize.area() > 0 in function cv::resize"

Turns out for me this error was actually telling the truth - I was trying to resize a Null image, which was usually the 'last' frame of a video file, so the assertion was valid.

Now I have an extra step before attempting the resize operation, which is to do the assertion myself:

def getSizedFrame(width, height):
"""Function to return an image with the size I want"""    
    s, img = self.cam.read()

    # Only process valid image frames
    if s:
            img = cv2.resize(img, (width, height), interpolation = cv2.INTER_AREA)
    return s, img

Now I don't see the error.

SHA512 vs. Blowfish and Bcrypt

Blowfish isn't better than MD5 or SHA512, as they serve different purposes. MD5 and SHA512 are hashing algorithms, Blowfish is an encryption algorithm. Two entirely different cryptographic functions.

How to save a list as numpy array in python?

You want to save it as a file?

import numpy as np

myList = [1, 2, 3]

np.array(myList).dump(open('array.npy', 'wb'))

... and then read:

myArray = np.load(open('array.npy', 'rb'))

Byte Array to Image object

Since it sounds like you already know what format the byte[] array is in (e.g. RGB, ARGB, BGR etc.) you might be able to use BufferedImage.setRGB(...), or a combination of BufferedImage.getRaster() and WritableRaster.setPixels(...) or WritableRaster.setSamples(...). Unforunately both of these methods require you transform your byte[] into one of int[], float[] or double[] depending on the image format.

C# Pass Lambda Expression as Method Parameter

You should use a delegate type and specify that as your command parameter. You could use one of the built in delegate types - Action and Func.

In your case, it looks like your delegate takes two parameters, and returns a result, so you could use Func:

List<IJob> GetJobs(Func<FullTimeJob, Student, FullTimeJob> projection)

You could then call your GetJobs method passing in a delegate instance. This could be a method which matches that signature, an anonymous delegate, or a lambda expression.

P.S. You should use PascalCase for method names - GetJobs, not getJobs.

Get current url in Angular

You can make use of location service available in @angular/common and via this below code you can get the location or current URL

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

@Component({
  selector: 'app-top-nav',
  templateUrl: './top-nav.component.html',
  styleUrls: ['./top-nav.component.scss']
})
export class TopNavComponent implements OnInit {

  route: string;

  constructor(location: Location, router: Router) {
    router.events.subscribe((val) => {
      if(location.path() != ''){
        this.route = location.path();
      } else {
        this.route = 'Home'
      }
    });
  }

  ngOnInit() {
  }

}

here is the reference link from where I have copied thing to get location for my project. https://github.com/elliotforbes/angular-2-admin/blob/master/src/app/common/top-nav/top-nav.component.ts

What do we mean by Byte array?

A byte is 8 bits (binary data).

A byte array is an array of bytes (tautology FTW!).

You could use a byte array to store a collection of binary data, for example, the contents of a file. The downside to this is that the entire file contents must be loaded into memory.

For large amounts of binary data, it would be better to use a streaming data type if your language supports it.

Add comma to numbers every three digits

Use function Number();

_x000D_
_x000D_
$(function() {_x000D_
_x000D_
  var price1 = 1000;_x000D_
  var price2 = 500000;_x000D_
  var price3 = 15245000;_x000D_
_x000D_
  $("span#s1").html(Number(price1).toLocaleString('en'));_x000D_
  $("span#s2").html(Number(price2).toLocaleString('en'));_x000D_
  $("span#s3").html(Number(price3).toLocaleString('en'));_x000D_
_x000D_
  console.log(Number(price).toLocaleString('en'));_x000D_
_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
_x000D_
<span id="s1"></span><br />_x000D_
<span id="s2"></span><br />_x000D_
<span id="s3"></span><br />
_x000D_
_x000D_
_x000D_

Disabling and enabling a html input button

the disable attribute only has one parameter. if you want to reenable it you have to remove the whole thing, not just change the value.

Delete a row from a table by id

Something quick and dirty:

<script type='text/javascript'>
function del_tr(remtr)  
{   
    while((remtr.nodeName.toLowerCase())!='tr')
        remtr = remtr.parentNode;

    remtr.parentNode.removeChild(remtr);
}
function del_id(id)  
{   
        del_tr(document.getElementById(id));
}
</script>

if you place

<a href='' onclick='del_tr(this);return false;'>x</a>

anywhere within the row you want to delete, than its even working without any ids

Turn off enclosing <p> tags in CKEditor 3.0

Across the internet, people have noticed that setting config.enterMode to CKEDITOR.ENTER_BR removes the wrapping paragraph tags from CKEditor. It's worth noting that the setting changes the behavior of the enter key to insert line breaks rather than paragraphs, which is not desirable.

See: http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.config.html#.enterMode "It is recommended to use the CKEDITOR.ENTER_P setting because of its semantic value and correctness."

However, the setting that is designed to remove that initial paragraph, config.autoParagraph, isn't advisable either, as it introduces "unpredictable usability issues" because the editor really wants a top-level block element.

See: http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.config.html#.autoParagraph

The magic happens on wysiwygarea/plugin.js, line 410, where the editor selects the default block element based on config.enterMode. A config option to change the default block element would allow us to start with a div, but we'd continue getting more divs with every enter press, unless we changed the paragraph format via the menu.

See: http://docs.cksource.com/ckeditor_api/symbols/src/plugins_wysiwygarea_plugin.js.html

It would be possible to remove the wrapping paragraph tag with post-processing (either on the server or in CKEditor's getData event), but that leads us into the same problem as disabling autoParagraph: there's no top-level block.

I would rather say that there's not a good solution, but rather a handful of half-solutions, than to accept changing config.enterMode as the canonical solution.

"Uncaught TypeError: undefined is not a function" - Beginner Backbone.js Application

Uncaught TypeError: undefined is not a function example_app.js:7

This error message tells the whole story. On this line, you are trying to execute a function. However, whatever is being executed is not a function! Instead, it's undefined.

So what's on example_app.js line 7? Looks like this:

var tasks = new ExampleApp.Collections.Tasks(data.tasks);

There is only one function being run on that line. We found the problem! ExampleApp.Collections.Tasks is undefined.

So lets look at where that is declared:

var Tasks = Backbone.Collection.extend({
    model: Task,
    url: '/tasks'
});

If that's all the code for this collection, then the root cause is right here. You assign the constructor to global variable, called Tasks. But you never add it to the ExampleApp.Collections object, a place you later expect it to be.

Change that to this, and I bet you'd be good.

ExampleApp.Collections.Tasks = Backbone.Collection.extend({
    model: Task,
    url: '/tasks'
});

See how important the proper names and line numbers are in figuring this out? Never ever regard errors as binary (it works or it doesn't). Instead read the error, in most cases the error message itself gives you the critical clues you need to trace through to find the real issue.


In Javascript, when you execute a function, it's evaluated like:

expression.that('returns').aFunctionObject(); // js
execute -> expression.that('returns').aFunctionObject // what the JS engine does

That expression can be complex. So when you see undefined is not a function it means that expression did not return a function object. So you have to figure out why what you are trying to execute isn't a function.

And in this case, it was because you didn't put something where you thought you did.

How to send password using sftp batch file

You'll want to install the sshpass program. Then:

sshpass -p YOUR_PASSWORD sftp -oBatchMode=no -b YOUR_COMMAND_FILE_PATH USER@HOST

Obviously, it's better to setup public key authentication. Only use this if that's impossible to do, for whatever reason.

What exactly does stringstream do?

From C++ Primer:

The istringstream type reads a string, ostringstream writes a string, and stringstream reads and writes the string.

I come across some cases where it is both convenient and concise to use stringstream.

case 1

It is from one of the solutions for this leetcode problem. It demonstrates a very suitable case where the use of stringstream is efficient and concise.

Suppose a and b are complex numbers expressed in string format, we want to get the result of multiplication of a and b also in string format. The code is as follows:

string a = "1+2i", b = "1+3i";
istringstream sa(a), sb(b);
ostringstream out;

int ra, ia, rb, ib;
char buff;
// only read integer values to get the real and imaginary part of 
// of the original complex number
sa >> ra >> buff >> ia >> buff;
sb >> rb >> buff >> ib >> buff;

out << ra*rb-ia*ib << '+' << ra*ib+ia*rb << 'i';

// final result in string format
string result = out.str() 

case 2

It is also from a leetcode problem that requires you to simplify the given path string, one of the solutions using stringstream is the most elegant that I have seen:

string simplifyPath(string path) {
    string res, tmp;
    vector<string> stk;
    stringstream ss(path);
    while(getline(ss,tmp,'/')) {
        if (tmp == "" or tmp == ".") continue;
        if (tmp == ".." and !stk.empty()) stk.pop_back();
        else if (tmp != "..") stk.push_back(tmp);
    }
    for(auto str : stk) res += "/"+str;
    return res.empty() ? "/" : res; 
 }

Without the use of stringstream, it would be difficult to write such concise code.

Add multiple items to already initialized arraylist in java

If you are looking to avoid multiple code lines to save space, maybe this syntax could be useful:

        java.util.ArrayList lisFieldNames = new ArrayList() {
            {
                add("value1"); 
                add("value2");
            }
        };

Removing new lines, you can show it compressed as:

        java.util.ArrayList lisFieldNames = new ArrayList() {
            {
                add("value1"); add("value2"); (...);
            }
        };

How to get the current branch name in Git?

Well simple enough, I got it in a one liner (bash)

git branch | sed -n '/\* /s///p'

(credit: Limited Atonement)

And while I am there, the one liner to get the remote tracking branch (if any)

git rev-parse --symbolic-full-name --abbrev-ref @{u}

How to check if array is not empty?

len(self.table) checks for the length of the array, so you can use if-statements to find out if the length of the list is greater than 0 (not empty):

Python 2:

if len(self.table) > 0:
    #Do code here

Python 3:

if(len(self.table) > 0):
    #Do code here

It's also possible to use

if self.table:
    #Execute if self.table is not empty
else:
    #Execute if self.table is empty

to see if the list is not empty.

How to get the Display Name Attribute of an Enum member via MVC Razor code?

You could use Type.GetMember Method, then get the attribute info using reflection:

// display attribute of "currentPromotion"

var type = typeof(UserPromotion);
var memberInfo = type.GetMember(currentPromotion.ToString());
var attributes = memberInfo[0].GetCustomAttributes(typeof(DisplayAttribute), false);
var description = ((DisplayAttribute)attributes[0]).Name;

There were a few similar posts here:

Getting attributes of Enum's value

How to make MVC3 DisplayFor show the value of an Enum's Display-Attribute?

Group array items using object

_x000D_
_x000D_
myArray = [_x000D_
  {group: "one", color: "red"},_x000D_
  {group: "two", color: "blue"},_x000D_
  {group: "one", color: "green"},_x000D_
  {group: "one", color: "black"}_x000D_
];_x000D_
_x000D_
_x000D_
let group = myArray.map((item)=>  item.group ).filter((item, i, ar) => ar.indexOf(item) === i).sort((a, b)=> a - b).map(item=>{_x000D_
    let new_list = myArray.filter(itm => itm.group == item).map(itm=>itm.color);_x000D_
    return {group:item,color:new_list}_x000D_
});_x000D_
console.log(group);
_x000D_
_x000D_
_x000D_

Compare two objects with .equals() and == operator

Statements a == object2 and a.equals(object2) both will always return false because a is a string while object2 is an instance of MyClass

How to make a view with rounded corners?

Another approach is to make a custom layout class like the one below. This layout first draws its contents to an offscreen bitmap, masks the offscreen bitmap with a rounded rect and then draws the offscreen bitmap on the actual canvas.

I tried it and it seems to work (at least for my simple testcase). It will of course affect performance compared to a regular layout.

package com.example;

import android.content.Context;
import android.graphics.*;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.widget.FrameLayout;

public class RoundedCornerLayout extends FrameLayout {
    private final static float CORNER_RADIUS = 40.0f;

    private Bitmap maskBitmap;
    private Paint paint, maskPaint;
    private float cornerRadius;

    public RoundedCornerLayout(Context context) {
        super(context);
        init(context, null, 0);
    }

    public RoundedCornerLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    public RoundedCornerLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs, defStyle);
    }

    private void init(Context context, AttributeSet attrs, int defStyle) {
        DisplayMetrics metrics = context.getResources().getDisplayMetrics();
        cornerRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, CORNER_RADIUS, metrics);

        paint = new Paint(Paint.ANTI_ALIAS_FLAG);

        maskPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
        maskPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));

        setWillNotDraw(false);
    }

    @Override
    public void draw(Canvas canvas) {
        Bitmap offscreenBitmap = Bitmap.createBitmap(canvas.getWidth(), canvas.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas offscreenCanvas = new Canvas(offscreenBitmap);

        super.draw(offscreenCanvas);

        if (maskBitmap == null) {
            maskBitmap = createMask(canvas.getWidth(), canvas.getHeight());
        }

        offscreenCanvas.drawBitmap(maskBitmap, 0f, 0f, maskPaint);
        canvas.drawBitmap(offscreenBitmap, 0f, 0f, paint);
    }

    private Bitmap createMask(int width, int height) {
        Bitmap mask = Bitmap.createBitmap(width, height, Bitmap.Config.ALPHA_8);
        Canvas canvas = new Canvas(mask);

        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(Color.WHITE);

        canvas.drawRect(0, 0, width, height, paint);

        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
        canvas.drawRoundRect(new RectF(0, 0, width, height), cornerRadius, cornerRadius, paint);

        return mask;
    }
}

Use this like a normal layout:

<com.example.RoundedCornerLayout
    android:layout_width="200dp"
    android:layout_height="200dp">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/test"/>

    <View
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:background="#ff0000"
        />

</com.example.RoundedCornerLayout>

error_log per Virtual Host?

I usually just specify this in an .htaccess file or the vhost.conf on the domain I'm working on. Add this to one of these files:

php_admin_value error_log "/var/www/vhosts/example.com/error_log"

How to split a data frame?

If you want to split by values in one of the columns, you can use lapply. For instance, to split ChickWeight into a separate dataset for each chick:

data(ChickWeight)
lapply(unique(ChickWeight$Chick), function(x) ChickWeight[ChickWeight$Chick == x,])

C# refresh DataGridView when updating or inserted on another form

my datagridview is editonEnter mode . so it refresh only after i leave cell or after i revisit and exit cell twice.

to trigger this iimedately . i unfocus from datagridview . then refocus it.

 this.SelectNextControl(dgv1,true,true,false,true);    
 Application.DoEvents();    //this does magic
 dgv1.Focus();

Origin null is not allowed by Access-Control-Allow-Origin

I would like to humbly add that according to this SO source: https://stackoverflow.com/a/14671362/1743693, this kind of trouble is now partially solved simply by using the following jQuery instruction:

<script> 
    $.support.cors = true;
</script>

I tried it on IE10.0.9200, and it worked immediately (using jquery-1.9.0.js).

On chrome 28.0.1500.95 - this instruction doesn't work (this happens all over as david complains in the comments at the link above)

Running chrome with --allow-file-access-from-files did not work for me (as Maistora's claims above)

Best way to store a key=>value array in JavaScript?

Simply do this

var key = "keyOne";
var obj = {};
obj[key] = someValue;

What is the difference between JavaScript and jQuery?

Javascript is base of jQuery.

jQuery is a wrapper of JavaScript, with much pre-written functionality and DOM traversing.

How does one sum only those rows in excel not filtered out?

If you aren't using an auto-filter (i.e. you have manually hidden rows), you will need to use the AGGREGATE function instead of SUBTOTAL.

ASP.NET MVC Razor: How to render a Razor Partial View's HTML inside the controller action

Although adequate answers have already been given, I'd like to propose a less verbose solution, that can be used without the helper methods available in an MVC controller class. Using a third party library called "RazorEngine" you can use .Net file IO to get the contents of the razor file and call

string html = Razor.Parse(razorViewContentString, modelObject);

Get the third party library here.

Is there an embeddable Webkit component for Windows / C# development?

There's a WebKit-Sharp component on Mono's Subversion Server. I can't find any web-viewable documentation on it, and I'm not even sure if it's WinForms or GTK# (can't grab the source from here to check at the moment), but it's probably your best bet, either way.

I think this component is CLI wrapper around webkit for Ubuntu. So this wrapper most likely could be not working on win32

Try check another variant - project awesomium - wrapper around google project "Chromium" that use webkit. Also awesomium has features like to should interavtive web pages on 3D objects under WPF

How to get text from EditText?

Put this in your MainActivity:

{
    public EditText bizname, storeno, rcpt, item, price, tax, total;
    public Button click, click2;
    int contentView;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.main_activity );
        bizname = (EditText) findViewById( R.id.editBizName );
        item = (EditText) findViewById( R.id.editItem );
        price = (EditText) findViewById( R.id.editPrice );
        tax = (EditText) findViewById( R.id.editTax );
        total = (EditText) findViewById( R.id.editTotal );
        click = (Button) findViewById( R.id.button );
    }
}

Put this under a button or something

public void clickBusiness(View view) {
    checkPermsOfStorage( this );

    bizname = (EditText) findViewById( R.id.editBizName );
    item = (EditText) findViewById( R.id.editItem );
    price = (EditText) findViewById( R.id.editPrice );
    tax = (EditText) findViewById( R.id.editTax );
    total = (EditText) findViewById( R.id.editTotal );
    String x = ("\nItem/Price: " + item.getText() + price.getText() + "\nTax/Total" + tax.getText() + total.getText());
    Toast.makeText( this, x, Toast.LENGTH_SHORT ).show();
    try {
        this.WriteBusiness(bizname,storeno,rcpt,item,price,tax,total);
        String vv = tax.getText().toString();
        System.console().printf( "%s", vv );
        //new XMLDivisionWriter(getString(R.string.SDDoc) + "/tax_div_business.xml");
    } catch (ReflectiveOperationException e) {
        e.printStackTrace();
    }
}

There! The debate is settled!

Google Maps V3 - How to calculate the zoom level for a given bounds

Dart Version:

  double latRad(double lat) {
    final double sin = math.sin(lat * math.pi / 180);
    final double radX2 = math.log((1 + sin) / (1 - sin)) / 2;
    return math.max(math.min(radX2, math.pi), -math.pi) / 2;
  }

  double getMapBoundZoom(LatLngBounds bounds, double mapWidth, double mapHeight) {
    final LatLng northEast = bounds.northEast;
    final LatLng southWest = bounds.southWest;

    final double latFraction = (latRad(northEast.latitude) - latRad(southWest.latitude)) / math.pi;

    final double lngDiff = northEast.longitude - southWest.longitude;
    final double lngFraction = ((lngDiff < 0) ? (lngDiff + 360) : lngDiff) / 360;

    final double latZoom = (math.log(mapHeight / 256 / latFraction) / math.ln2).floorToDouble();
    final double lngZoom = (math.log(mapWidth / 256 / lngFraction) / math.ln2).floorToDouble();

    return math.min(latZoom, lngZoom);
  }

jquery: get value of custom attribute

You need some form of iteration here, as val (except when called with a function) only works on the first element:

$("input[placeholder]").val($("input[placeholder]").attr("placeholder"));

should be:

$("input[placeholder]").each( function () {
    $(this).val( $(this).attr("placeholder") );
});

or

$("input[placeholder]").val(function() {
    return $(this).attr("placeholder");
});

How do I get SUM function in MySQL to return '0' if no values are found?

if sum of column is 0 then display empty

select if(sum(column)>0,sum(column),'')
from table 

What is base 64 encoding used for?

The usage of Base64 I'm going to describe here is somewhat a hack. So if you don't like hacks, please do not go on.

I went into trouble when I discovered that MySQL's utf8 does not support 4-byte unicode characters since it uses a 3-byte version of utf8. So what I did to support full 4-byte unicode over MySQL's utf8? Well, base64 encode strings when storing into the database and base64 decode when retrieving.

Since base64 encoding and decoding is very fast, the above worked perfectly.

You have the following points to take note of:

  • Base64 encoding uses 33% more storage

  • Strings stored in the database wont be human readable (You could sell that as a feature that database strings use a basic form of encryption).

You could use the above method for any storage engine that does not support unicode.

How to disable action bar permanently

I use this solution:

in the manifest, inside your activity tag:

android:label="@string/empty_string"

and in strings.xml:

<string name="empty_string">""</string>

This way you keep ActionBar (or Toolbar) with the title, but when Activity if created the title is automatically empty.

How to set app icon for Electron / Atom Shell App

**

IMPORTANT: OUTDATED ANSWER, LOOK AT THE OTHER NEWER SOLUTIONS

**

You can do it for macOS, too. Ok, not through code, but with some simple steps:

  1. Find the .icns file you want to use, open it and copy it via Edit menu
  2. Find the electron.app, usually in node_modules/electron/dist
  3. Open the information window
  4. Select the icon on the top left corner (gray border around it)
  5. Paste the icon via cmd+v
  6. Enjoy your icon during development :-)

enter image description here

Actually it is a general thing not specific to electron. You can change the icon of many macOS apps like this.

Why compile Python code?

It's compiled to bytecode which can be used much, much, much faster.

The reason some files aren't compiled is that the main script, which you invoke with python main.py is recompiled every time you run the script. All imported scripts will be compiled and stored on the disk.

Important addition by Ben Blank:

It's worth noting that while running a compiled script has a faster startup time (as it doesn't need to be compiled), it doesn't run any faster.

java.lang.ClassNotFoundException: sun.jdbc.odbc.JdbcOdbcDriver Exception occurring. Why?

Setup:

My OS windows 8 64bit
Eclipse version Standard/SDK Kepler Service Release 2
My JDK is jdk-8u5-windows-i586
My JRE is jre-8u5-windows-i586

This how I overcome my error.

At the very first my Class.forName("sun.jdbc.odbc.JdbcOdbcDriver") also didn't work. Then I login to this website and downloaded the UCanAccess 2.0.8 zip (as Mr.Gord Thompson said) file and unzip it.

Then you will also able to find these *.jar files in that unzip folder:

ucanaccess-2.0.8.jar
commons-lang-2.6.jar
commons-logging-1.1.1.jar
hsqldb.jar
jackcess-2.0.4.jar

Then what I did was I copied all these 5 files and paste them in these 2 locations:

C:\Program Files (x86)\eclipse\lib
C:\Program Files (x86)\eclipse\lib\ext

(I did that funny thing becoz I was unable to import these libraries to my project)

Then I reopen the eclipse with my project.then I see all that *.jar files in my project's JRE System Library folder.

Finally my code works.

public static void main(String[] args) 
{

    try
    {

        Connection conn=DriverManager.getConnection("jdbc:ucanaccess://C:\\Users\\Hasith\\Documents\\JavaDatabase1.mdb");
        Statement stment = conn.createStatement();
        String qry = "SELECT * FROM Table1";

        ResultSet rs = stment.executeQuery(qry);
        while(rs.next())
        {
            String id    = rs.getString("ID") ;
            String fname = rs.getString("Nama");

            System.out.println(id + fname);
        }
    }
    catch(Exception err)
    {
        System.out.println(err);
    }


    //System.out.println("Hasith Sithila");

}

Pass a list to a function to act as multiple arguments

Yes, you can use the *args (splat) syntax:

function_that_needs_strings(*my_list)

where my_list can be any iterable; Python will loop over the given object and use each element as a separate argument to the function.

See the call expression documentation.

There is a keyword-parameter equivalent as well, using two stars:

kwargs = {'foo': 'bar', 'spam': 'ham'}
f(**kwargs)

and there is equivalent syntax for specifying catch-all arguments in a function signature:

def func(*args, **kw):
    # args now holds positional arguments, kw keyword arguments

Convert Month Number to Month Name Function in SQL

Starting with SQL Server 2012, you can use FORMAT and DATEFROMPARTS to solve this problem. (If you want month names from other cultures, change: en-US)

select FORMAT(DATEFROMPARTS(1900, @month_num, 1), 'MMMM', 'en-US')

If you want a three-letter month:

select FORMAT(DATEFROMPARTS(1900, @month_num, 1), 'MMM', 'en-US')

If you really want to, you can create a function for this:

CREATE FUNCTION fn_month_num_to_name
(
    @month_num tinyint
)
RETURNS varchar(20)
AS
BEGIN
    RETURN FORMAT(DATEFROMPARTS(1900, @month_num, 1), 'MMMM', 'en-US')
END

Specifying Font and Size in HTML table

This worked for me and also worked with bootstrap tables

<style>
    .table td, .table th {
        font-size: 10px;
    }
</style>

Selenium Webdriver: Entering text into text field

Use this code.

driver.FindElement(By.XPath(".//[@id='header']/div/div[3]/div/form/input[1]")).SendKeys("25025");

Get value of a string after last slash in JavaScript

At least three ways:

A regular expression:

var result = /[^/]*$/.exec("foo/bar/test.html")[0];

...which says "grab the series of characters not containing a slash" ([^/]*) at the end of the string ($). Then it grabs the matched characters from the returned match object by indexing into it ([0]); in a match object, the first entry is the whole matched string. No need for capture groups.

Live example

Using lastIndexOf and substring:

var str = "foo/bar/test.html";
var n = str.lastIndexOf('/');
var result = str.substring(n + 1);

lastIndexOf does what it sounds like it does: It finds the index of the last occurrence of a character (well, string) in a string, returning -1 if not found. Nine times out of ten you probably want to check that return value (if (n !== -1)), but in the above since we're adding 1 to it and calling substring, we'd end up doing str.substring(0) which just returns the string.

Using Array#split

Sudhir and Tom Walters have this covered here and here, but just for completeness:

var parts = "foo/bar/test.html".split("/");
var result = parts[parts.length - 1]; // Or parts.pop();

split splits up a string using the given delimiter, returning an array.

The lastIndexOf / substring solution is probably the most efficient (although one always has to be careful saying anything about JavaScript and performance, since the engines vary so radically from each other), but unless you're doing this thousands of times in a loop, it doesn't matter and I'd strive for clarity of code.

Center image in div horizontally

A very simple and elegant solution to this is provided by W3C. Simply use the margin:0 auto declaration as follows:

.top_image img { margin:0 auto; }

More information and examples from W3C.

Create hive table using "as select" or "like" and also specify delimiter

Both the answers provided above work fine.

  1. CREATE TABLE person AS select * from employee;
  2. CREATE TABLE person LIKE employee;

Convert String to Double - VB

The international versions:

    Public Shared Function GetDouble(ByVal doublestring As String) As Double
        Dim retval As Double
        Dim sep As String = CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator

        Double.TryParse(Replace(Replace(doublestring, ".", sep), ",", sep), retval)
        Return retval
    End Function

    ' NULLABLE VERSION:
    Public Shared Function GetDoubleNullable(ByVal doublestring As String) As Double?
        Dim retval As Double
        Dim sep As String = CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator

        If Double.TryParse(Replace(Replace(doublestring, ".", sep), ",", sep), retval) Then
            Return retval
        Else
            Return Nothing
        End If
    End Function

Results:

        ' HUNGARIAN REGIONAL SETTINGS (NumberDecimalSeparator: ,)

        ' Clean Double.TryParse
        ' -------------------------------------------------
        Double.TryParse("1.12", d1)     ' Type: DOUBLE     Value: d1 = 0.0
        Double.TryParse("1,12", d2)     ' Type: DOUBLE     Value: d2 = 1.12
        Double.TryParse("abcd", d3)     ' Type: DOUBLE     Value: d3 = 0.0

        ' GetDouble() method
        ' -------------------------------------------------
        d1 = GetDouble("1.12")          ' Type: DOUBLE     Value: d1 = 1.12
        d2 = GetDouble("1,12")          ' Type: DOUBLE     Value: d2 = 1.12
        d3 = GetDouble("abcd")          ' Type: DOUBLE     Value: d3 = 0.0

        ' Nullable version - GetDoubleNullable() method
        ' -------------------------------------------------
        d1n = GetDoubleNullable("1.12") ' Type: DOUBLE?    Value: d1n = 1.12
        d2n = GetDoubleNullable("1,12") ' Type: DOUBLE?    Value: d2n = 1.12
        d3n = GetDoubleNullable("abcd") ' Type: DOUBLE?    Value: d3n = Nothing

Uninstalling an MSI file from the command line without using msiexec

I would try the following syntax - it works for me.

msiexec /x filename.msi /q 

How to get the Mongo database specified in connection string in C#

With version 1.7 of the official 10gen driver, this is the current (non-obsolete) API:

const string uri = "mongodb://localhost/mydb";
var client = new MongoClient(uri);
var db = client.GetServer().GetDatabase(new MongoUrl(uri).DatabaseName);
var collection = db.GetCollection("mycollection");

Static extension methods

specifically I want to overload Boolean.Parse to allow an int argument.

Would an extension for int work?

public static bool ToBoolean(this int source){
    // do it
    // return it
}

Then you can call it like this:

int x = 1;

bool y = x.ToBoolean();

What does "to stub" mean in programming?

You have also a very good testing frameworks to create such a stub. One of my preferrable is Mockito There is also EasyMock and others... But Mockito is great you should read it - very elegant and powerfull package

Change Orientation of Bluestack : portrait/landscape mode

I install go launcher on mine, (Windows 8)=> preferences => Screens => Screen orientation => vertical (disable QWE keyboard)

What is JSONP, and why was it created?

JSONP is a great away to get around cross-domain scripting errors. You can consume a JSONP service purely with JS without having to implement a AJAX proxy on the server side.

You can use the b1t.co service to see how it works. This is a free JSONP service that alllows you to minify your URLs. Here is the url to use for the service:

http://b1t.co/Site/api/External/MakeUrlWithGet?callback=[resultsCallBack]&url=[escapedUrlToMinify]

For example the call, http://b1t.co/Site/api/External/MakeUrlWithGet?callback=whateverJavascriptName&url=google.com

would return

whateverJavascriptName({"success":true,"url":"http://google.com","shortUrl":"http://b1t.co/54"});

And thus when that get's loaded in your js as a src, it will automatically run whateverJavascriptName which you should implement as your callback function:

function minifyResultsCallBack(data)
{
    document.getElementById("results").innerHTML = JSON.stringify(data);
}

To actually make the JSONP call, you can do it about several ways (including using jQuery) but here is a pure JS example:

function minify(urlToMinify)
{
   url = escape(urlToMinify);
   var s = document.createElement('script');
   s.id = 'dynScript';
   s.type='text/javascript';
   s.src = "http://b1t.co/Site/api/External/MakeUrlWithGet?callback=resultsCallBack&url=" + url;
   document.getElementsByTagName('head')[0].appendChild(s);
}

A step by step example and a jsonp web service to practice on is available at: this post

How to check the installed version of React-Native

To see the local packages installed in your project including their versions and without their dependencies, run the below command from the project's root directory. In a React native app this would include the react-native package.

npm list --depth 0

Or if you installed them with yarn:

yarn list --depth=0

And to get just a specific package:

npm list react-native --depth 0
yarn list --pattern react-native --depth=0

Programmatically check Play Store for app updates

Include JSoup in your apps build.gradle file :

dependencies {
    compile 'org.jsoup:jsoup:1.8.3'
}

and get current version like :

currentVersion = getPackageManager().getPackageInfo(getPackageName(), 0).versionName;

And execute following thread :

private class GetVersionCode extends AsyncTask<Void, String, String> {
    @Override
    protected String doInBackground(Void... voids) {

    String newVersion = null;
    try {
        newVersion = Jsoup.connect("https://play.google.com/store/apps/details?id=" + MainActivity.this.getPackageName() + "&hl=it")
                .timeout(30000)
                .userAgent("Mozilla/5.0 (Windows; U; WindowsNT 5.1; en-US; rv1.8.1.6) Gecko/20070725 Firefox/2.0.0.6")
                .referrer("http://www.google.com")
                .get()
                .select(".hAyfc .htlgb")
                .get(7)
                .ownText();
        return newVersion;
    } catch (Exception e) {
        return newVersion;
    }
    }

    @Override
    protected void onPostExecute(String onlineVersion) {
        super.onPostExecute(onlineVersion);
        Log.d("update", "Current version " + currentVersion + "playstore version " + onlineVersion);
        if (onlineVersion != null && !onlineVersion.isEmpty()) {
            if (Float.valueOf(currentVersion) < Float.valueOf(onlineVersion)) {
                //show dialog
            }
        }
    }

For more details visit : http://revisitingandroid.blogspot.in/2016/12/programmatically-check-play-store-for.html

Space between Column's children in Flutter

You can use Padding widget in between those two widget or wrap those widgets with Padding widget.

Update

SizedBox widget can be use in between two widget to add space between two widget and it makes code more readable than padding widget.

Ex:

Column(
  children: <Widget>[
    Widget1(),
    SizedBox(height: 10),
    Widget2(),
  ],
),

Get JSONArray without array name?

I've assumed a named JSONArray is a JSONObject and accessed the data from the server to populate an Android GridView. For what it is worth my method is:

private String[] fillTable( JSONObject jsonObject ) {
   String[] dummyData = new String[] {"1", "2", "3", "4", "5", "6", "7","1", "2", "3", "4", "5", "6", "7","1", "2", "3", "4", "5", "6", "7", };
  if( jsonObject != null ) {
      ArrayList<String> data = new ArrayList<String>();
      try {
          // jsonArray looks like { "everything" : [{}, {},] }
          JSONArray jsonArray = jsonObject.getJSONArray( "everything" );
          int number = jsonArray.length(); //How many rows have got from the database?
          Log.i( Constants.INFORMATION, "Number of ows returned:  " + Integer.toString( number ) );
                  // Array elements look like this
          //{"success":1,"error":0,"name":"English One","owner":"Tutor","description":"Initial Alert","posted":"2013-08-09 15:35:40"}
          for( int element = 0; element < number; element++ ) { //visit each element
             JSONObject jsonObject_local = jsonArray.getJSONObject( element );
             //  Overkill on the error/success checking
             Log.e("JSON SUCCESS", Integer.toString( jsonObject_local.getInt(Constants.KEY_SUCCESS) ) );
             Log.e("JSON ERROR", Integer.toString( jsonObject_local.getInt(Constants.KEY_ERROR) ) );
                if ( jsonObject_local.getInt( Constants.KEY_SUCCESS) == Constants.JSON_SUCCESS ) {
                   String name = jsonObject_local.getString( Constants.KEY_NAME );
                   data.add( name );
                   String owner = jsonObject_local.getString( Constants.KEY_OWNER );
                   data.add( owner );
                   String description = jsonObject_local.getString( Constants.KEY_DESCRIPTION );
                   Log.i( "DESCRIPTION", description );
                   data.add( description ); 
                   String date = jsonObject_local.getString( Constants.KEY_DATE );
                   data.add( date );
                }
                else {
                    for( int i = 0; i < 4; i++ ) {
                        data.add( "ERROR" );
                    }
                }
          }
  }  //JSON object is null
  catch ( JSONException jsone) {
      Log.e( "JSON EXCEPTION", jsone.getMessage() );
  }
      dummyData = data.toArray( dummyData );
  }
  return dummyData;

}

The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

You may get your answer here: Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

UPDATE

It might be due to various issues.I cant say which one is there in your case. It may be because:

  • DCOM is not enabled in host pc or target pc or on both
  • your firewall or even your antivirus is preventing the access
  • any WMI related service is disabled

Some WMI related services are:

  • Remote Access Auto Connection Manager
  • Remote Access Connection Manager
  • Remote Procedure Call (RPC)
  • Remote Procedure Call (RPC) Locator
  • Remote Registry

For DCOM settings refer to registry key HKLM\Software\Microsoft\OLE, value EnableDCOM. The value should be set to 'Y'.

XML shape drawable not rendering desired color

In drawable I use this xml code to define the border and background:

<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
  <stroke android:width="4dp" android:color="#D8FDFB" /> 
  <padding android:left="7dp" android:top="7dp" 
    android:right="7dp" android:bottom="7dp" /> 
  <corners android:radius="4dp" /> 
  <solid android:color="#f0600000"/> 
</shape> 

Regex Named Groups in Java

What kind of problem do you get with jregex? It worked well for me under java5 and java6.

Jregex does the job well (even if the last version is from 2002), unless you want to wait for javaSE 7.

Python 3 Online Interpreter / Shell

Ideone supports Python 2.6 and Python 3

ANTLR: Is there a simple example?

For Antlr 4 the java code generation process is below:-

java -cp antlr-4.5.3-complete.jar org.antlr.v4.Tool Exp.g

Update your jar name in classpath accordingly.

assign multiple variables to the same value in Javascript

There is another option that does not introduce global gotchas when trying to initialize multiple variables to the same value. Whether or not it is preferable to the long way is a judgement call. It will likely be slower and may or may not be more readable. In your specific case, I think that the long way is probably more readable and maintainable as well as being faster.

The other way utilizes Destructuring assignment.

_x000D_
_x000D_
let [moveUp, moveDown,_x000D_
     moveLeft, moveRight,_x000D_
     mouseDown, touchDown] = Array(6).fill(false);_x000D_
_x000D_
console.log(JSON.stringify({_x000D_
    moveUp, moveDown,_x000D_
    moveLeft, moveRight,_x000D_
    mouseDown, touchDown_x000D_
}, null, '  '));_x000D_
_x000D_
// NOTE: If you want to do this with objects, you would be safer doing this_x000D_
let [obj1, obj2, obj3] = Array(3).fill(null).map(() => ({}));_x000D_
console.log(JSON.stringify({_x000D_
    obj1, obj2, obj3_x000D_
}, null, '  '));_x000D_
// So that each array element is a unique object_x000D_
_x000D_
// Or another cool trick would be to use an infinite generator_x000D_
let [a, b, c, d] = (function*() { while (true) yield {x: 0, y: 0} })();_x000D_
console.log(JSON.stringify({_x000D_
    a, b, c, d_x000D_
}, null, '  '));_x000D_
_x000D_
// Or generic fixed generator function_x000D_
function* nTimes(n, f) {_x000D_
    for(let i = 0; i < n; i++) {_x000D_
        yield f();_x000D_
    }_x000D_
}_x000D_
let [p1, p2, p3] = [...nTimes(3, () => ({ x: 0, y: 0 }))];_x000D_
console.log(JSON.stringify({_x000D_
    p1, p2, p3_x000D_
}, null, '  '));
_x000D_
_x000D_
_x000D_

This allows you to initialize a set of var, let, or const variables to the same value on a single line all with the same expected scope.

References:

Any implementation of Ordered Set in Java?

I had a similar problem. I didn't quite need an ordered set but more a list with a fast indexOf/contains. As I didn't find anything out there I implemented one myself. Here's the code, it implements both Set and List, though not all bulk list operations are as fast as the ArrayList versions.

disclaimer: not tested

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Set;
import java.util.Collection;
import java.util.Comparator;
import java.util.function.Predicate;
import java.util.function.UnaryOperator;
import static java.util.Objects.requireNonNull;

/**
 * An ArrayList that keeps an index of its content so that contains()/indexOf() are fast. Duplicate entries are
 * ignored as most other java Set's do.
 */
public class IndexedArraySet<E> extends ArrayList<E> implements Set<E> {

    public IndexedArraySet() { super(); }

    public IndexedArraySet(Iterable<E> c) {
        super();
        addAll(c);
    }

    private HashMap<E, Integer> indexMap = new HashMap<>();

    private void reindex() {
        indexMap.clear();
        int idx = 0;
        for (E item: this) {
            addToIndex(item, idx++);
        }
    }

    private E addToIndex(E e, int idx) {
        indexMap.putIfAbsent(requireNonNull(e), idx);
        return e;
    }

    @Override
    public boolean add(E e) {
        if(indexMap.putIfAbsent(requireNonNull(e), size()) != null) return false;
        super.add(e);
        return true;
    }

    @Override
    public boolean addAll(Collection<? extends E> c) {
        return addAll((Iterable<? extends E>) c);
    }
    public boolean addAll(Iterable<? extends E> c) {
        boolean rv = false;
        for (E item: c) {
            rv |= add(item);
        }
        return rv;
    }

    @Override
    public boolean contains(Object e) {
        return indexMap.containsKey(e);
    }

    @Override

    public int indexOf(Object e) {
        if (e == null) return -1;
        Integer i = indexMap.get(e);
        return (i == null) ? -1 : i;
    }

    @Override
    public int lastIndexOf(Object e) {
        return indexOf(e);
    }

    @Override @SuppressWarnings("unchecked")
    public Object clone() {
        IndexedArraySet clone = (IndexedArraySet) super.clone();
        clone.indexMap = (HashMap) indexMap.clone();
        return clone;
    }

    @Override
    public void add(int idx, E e) {
        if(indexMap.putIfAbsent(requireNonNull(e), -1) != null) return;
        super.add(idx, e);
        reindex();
    }

    @Override
    public boolean remove(Object e) {
        boolean rv;
        try { rv = super.remove(e); }
        finally { reindex(); }
        return rv;
    }

    @Override
    public void clear() {
        super.clear();
        indexMap.clear();
    }

    @Override
    public boolean addAll(int idx, Collection<? extends E> c) {
        boolean rv;
        try {
            for(E item : c) {
                // check uniqueness
                addToIndex(item, -1);
            }
            rv = super.addAll(idx, c);
        } finally {
            reindex();
        }
        return rv;
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        boolean rv;
        try { rv = super.removeAll(c); }
        finally { reindex(); }
        return rv;
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        boolean rv;
        try { rv = super.retainAll(c); }
        finally { reindex(); }
        return rv;
    }

    @Override
    public boolean removeIf(Predicate<? super E> filter) {
        boolean rv;
        try { rv = super.removeIf(filter); }
        finally { reindex(); }
        return rv;
    }

    @Override
    public void replaceAll(final UnaryOperator<E> operator) {
        indexMap.clear();
        try {
            int duplicates = 0;
            for (int i = 0; i < size(); i++) {
                E newval = requireNonNull(operator.apply(this.get(i)));
                if(indexMap.putIfAbsent(newval, i-duplicates) == null) {
                    super.set(i-duplicates, newval);
                } else {
                    duplicates++;
                }
            }
            removeRange(size()-duplicates, size());
        } catch (Exception ex) {
            // If there's an exception the indexMap will be inconsistent
            reindex();
            throw ex;
        }

    }

    @Override
    public void sort(Comparator<? super E> c) {
        try { super.sort(c); }
        finally { reindex(); }
    }
}

How to get the height of a body element

I believe that the body height being returned is the visible height. If you need the total page height, you could wrap your div tags in a containing div and get the height of that.

Heroku "psql: FATAL: remaining connection slots are reserved for non-replication superuser connections"

I actually tried to implement connection pooling on the django end using:

https://github.com/gmcguire/django-db-pool

but I still received this error, despite lowering the number of connections available to below the standard development DB quota of 20 open connections.

There is an article here about how to move your postgresql database to the free/cheap tier of Amazon RDS. This would allow you to set max_connections higher. This will also allow you to pool connections at the database level using PGBouncer.

https://www.lewagon.com/blog/how-to-migrate-heroku-postgres-database-to-amazon-rds

UPDATE:

Heroku responded to my open ticket and stated that my database was improperly load balanced in their network. They said that improvements to their system should prevent similar problems in the future. Nonetheless, support manually relocated my database and performance is noticeably improved.

Access localhost from the internet

You go into your router configuration and forward port 80 to the LAN IP of the computer running the web server.

Then anyone outside your network (but not you inside the network) can access your site using your WAN IP address (whatismyipcom).

HTML form with side by side input fields

You should put the input for the last name into the same div where you have the first name.

<div>
    <label for="username">First Name</label>
    <input id="user_first_name" name="user[first_name]" size="30" type="text" />
    <input id="user_last_name" name="user[last_name]" size="30" type="text" />
</div>

Then, in your CSS give your #user_first_name and #user_last_name height and float them both to the left. For example:

#user_first_name{
    max-width:100px; /*max-width for responsiveness*/
    float:left;
}

#user_lastname_name{
    max-width:100px;
    float:left;
}

Publish to IIS, setting Environment Variable

Similar to other answers, I wanted to ensure my ASP.NET Core 2.1 environment setting persisted across deployments, but also only applied to the specific site.

According to Microsoft's documentation, it is possible to set the environment variable on the app pool using the following PowerShell command in IIS 10:

$appPoolName = "AppPool"
$envName = "Development"
cd "$env:SystemRoot\system32\inetsrv"
.\appcmd.exe set config -section:system.applicationHost/applicationPools /+"[name='$appPoolName'].environmentVariables.[name='ASPNETCORE_ENVIRONMENT',value='$envName']" /commit:apphost

I unfortunately still have to use IIS 8.5 and thought I was out of luck. However, it is still possible to run a simple PowerShell script to set a site-specific environment variable value for ASPNETCORE_ENVIRONMENT:

Import-Module -Name WebAdministration
$siteName = "Site"
$envName = "Development"
Set-WebConfigurationProperty -PSPath IIS:\ -Location $siteName -Filter /system.webServer/aspNetCore/environmentVariables -Name . -Value @{ Name = 'ASPNETCORE_ENVIRONMENT'; Value = $envName }

How to change date format using jQuery?

You don't need any date-specific functions for this, it's just string manipulation:

var parts = fecha2.value.split('-');
var newdate = parts[1]+'-'+parts[2]+'-'+(parseInt(parts[0], 10)%100);

Docker command can't connect to Docker daemon

For Ubuntu:
Happened with me when I updated docker.
You need to unmask the service and socket and then restart the service.

Following worked for me:

systemctl unmask docker.service
systemctl unmask docker.socket
systemctl start docker.service

What happend behind the scenes
systemd also has the ability to mark a unit as completely unstartable, automatically or manually, by linking it to /dev/null. This is called masking the unit, and is possible with the mask command.

sudo systemctl mask docker.service

You can check the list of masked services using:

sudo systemctl list-unit-files

Output of sudo systemctl list-unit-files

To enable auto/manual start of service you need to unmask it using:

sudo sytemctl unmask docker.service

Now the service will be enabled as shown below enter image description here

What is the best way to update the entity in JPA

That depends on what you want to do, but as you said, getting an entity reference using find() and then just updating that entity is the easiest way to do that.

I'd not bother about performance differences of the various methods unless you have strong indications that this really matters.

Function return value in PowerShell

PowerShell has really wacky return semantics - at least when viewed from a more traditional programming perspective. There are two main ideas to wrap your head around:

  • All output is captured, and returned
  • The return keyword really just indicates a logical exit point

Thus, the following two script blocks will do effectively the exact same thing:

$a = "Hello, World"
return $a

 

$a = "Hello, World"
$a
return

The $a variable in the second example is left as output on the pipeline and, as mentioned, all output is returned. In fact, in the second example you could omit the return entirely and you would get the same behavior (the return would be implied as the function naturally completes and exits).

Without more of your function definition I can't say why you are getting a PSMethod object. My guess is that you probably have something a few lines up that is not being captured and is being placed on the output pipeline.

It is also worth noting that you probably don't need those semicolons - unless you are nesting multiple expressions on a single line.

You can read more about the return semantics on the about_Return page on TechNet, or by invoking the help return command from PowerShell itself.

Switch case with fallthrough?

Recent bash versions allow fall-through by using ;& in stead of ;;: they also allow resuming the case checks by using ;;& there.

for n in 4 14 24 34
do
  echo -n "$n = "
  case "$n" in
   3? )
     echo -n thirty-
     ;;&   #resume (to find ?4 later )
   "24" )
     echo -n twenty-
     ;&   #fallthru
   "4" | [13]4)
     echo -n four 
     ;;&  # resume ( to find teen where needed )
   "14" )
     echo -n teen
  esac
  echo 
done

sample output

4 = four
14 = fourteen
24 = twenty-four
34 = thirty-four

Npm Please try using this command again as root/administrator

What helped me on Windows 10 was just ticking off "Read Only" of project node_modules.

What is the best way to add options to a select from a JavaScript object with jQuery?

I found that this is simple and works great.

for (var i = 0; i < array.length; i++) {
    $('#clientsList').append($("<option></option>").text(array[i].ClientName).val(array[i].ID));
};

How to rebuild docker container in docker-compose.yml?

Maybe these steps are not quite correct, but I do like this:

stop docker compose: $ docker-compose down

remove the container: $ docker system prune -a

start docker compose: $ docker-compose up -d

How can I get screen resolution in java?

Here's some functional code (Java 8) which returns the x position of the right most edge of the right most screen. If no screens are found, then it returns 0.

  GraphicsDevice devices[];

  devices = GraphicsEnvironment.
     getLocalGraphicsEnvironment().
     getScreenDevices();

  return Stream.
     of(devices).
     map(GraphicsDevice::getDefaultConfiguration).
     map(GraphicsConfiguration::getBounds).
     mapToInt(bounds -> bounds.x + bounds.width).
     max().
     orElse(0);

Here are links to the JavaDoc.

GraphicsEnvironment.getLocalGraphicsEnvironment()
GraphicsEnvironment.getScreenDevices()
GraphicsDevice.getDefaultConfiguration()
GraphicsConfiguration.getBounds()

How do I create a message box with "Yes", "No" choices and a DialogResult?

Try this:

if (MessageBox.Show("Are you sure", "Title_here", MessageBoxButton.YesNo) == MessageBoxResult.Yes)
{
    Do something here for 'Yes'...
}

Where is the user's Subversion config file stored on the major operating systems?

In windows 7, 8, and 10 you can find at the following location

C:\Users\<user>\AppData\Roaming\Subversion

If you enter the following in the Windows Explorer address bar, it will take you right there.

%appdata%\Subversion

No log4j2 configuration file found. Using default configuration: logging only errors to the console

Stuffs I check to verify logging,

1) Check that there're no older log4j versions.

mvn dependency:tree | grep log ## ./gradlew dependencies | grep log
[INFO] +- com.prayagupd:log-service:jar:1.0:compile
[INFO] +- org.apache.logging.log4j:log4j-api:jar:2.6.2:compile
[INFO] +- org.apache.logging.log4j:log4j-core:jar:2.6.2:compile
[INFO] |  \- commons-logging:commons-logging:jar:1.1.1:compile

2) make sure I'm setting log4j2.json properly, which is done with -Dlog4j.configurationFile=???

val logConfig: PropertiesConfiguration = new PropertiesConfiguration("application.properties")
System.setProperty("log4j.configurationFile", logConfig.getString("log4j.config.file"))

println("log4j.configurationFile :: " + System.getProperty("log4j.configurationFile"))

or

Configurator.initialize(null, logConfig.getString("log4j.config.file"));

Also if auto detection is happening make sure the file name is log4j2.* not log4j.*

3) Another check is for parser for log4j2.json. Thanks log4j team for not providing parser within the API.

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.4.0</version>
</dependency>

This might throw an exception if can not find the json parser

[Fatal Error] log4j2.json:1:1: Content is not allowed in prolog.

Custom checkbox image android

If you are using custom adapters than android:focusable="false" and android:focusableInTouchMode="false" are nessesury to make list items clickable while using checkbox.

<CheckBox
        android:id="@+id/checkbox_fav"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:button="@drawable/checkbox_layout"/>

In drawable>checkbox_layout.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:drawable="@drawable/uncked_checkbox"
        android:state_checked="false"/>
    <item android:drawable="@drawable/selected_checkbox"
        android:state_checked="true"/>
    <item android:drawable="@drawable/uncked_checkbox"/>
</selector>

How to create a table from select query result in SQL Server 2008

Try using SELECT INTO....

SELECT ....
INTO     TABLE_NAME(table you want to create)
FROM source_table

Why is document.write considered a "bad practice"?

Another legitimate use of document.write comes from the HTML5 Boilerplate index.html example.

<!-- Grab Google CDN's jQuery, with a protocol relative URL; fall back to local if offline -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.6.3/jquery.min.js"></script>
<script>window.jQuery || document.write('<script src="js/libs/jquery-1.6.3.min.js"><\/script>')</script>

I've also seen the same technique for using the json2.js JSON parse/stringify polyfill (needed by IE7 and below).

<script>window.JSON || document.write('<script src="json2.js"><\/script>')</script>

Understanding React-Redux and mapStateToProps()

React-Redux connect is used to update store for every actions.

import { connect } from 'react-redux';

const AppContainer = connect(  
  mapStateToProps,
  mapDispatchToProps
)(App);

export default AppContainer;

It's very simply and clearly explained in this blog.

You can clone github project or copy paste the code from that blog to understand the Redux connect.

javascript, for loop defines a dynamic variable name

You cannot create different "variable names" but you can create different object properties. There are many ways to do whatever it is you're actually trying to accomplish. In your case I would just do

for (var i = myArray.length - 1; i >= 0; i--) {    console.log(eval(myArray[i])); }; 

More generally you can create object properties dynamically, which is the type of flexibility you're thinking of.

var result = {}; for (var i = myArray.length - 1; i >= 0; i--) {     result[myArray[i]] = eval(myArray[i]);   }; 

I'm being a little handwavey since I don't actually understand language theory, but in pure Javascript (including Node) references (i.e. variable names) are happening at a higher level than at runtime. More like at the call stack; you certainly can't manufacture them in your code like you produce objects or arrays. Browsers do actually let you do this anyway though it's terrible practice, via

window['myVarName'] = 'namingCollisionsAreFun';  

(per comment)

How do you hide the Address bar in Google Chrome for Chrome Apps?

Hitting F11 may work for you.(Full-screen mode)

It appears that the hiding the address bar without going full screen is no longer an option:http://productforums.google.com/forum/#!topic/chrome/d7LfleRNX7M

Setting table row height

once I need to fix the height of a particular valued row by using inline CSS as following..

<tr><td colspan="4" style="height: 10px;">xxxyyyzzz</td></tr>

C - split string into an array of strings

Here is an example of how to use strtok borrowed from MSDN.

And the relevant bits, you need to call it multiple times. The token char* is the part you would stuff into an array (you can figure that part out).

char string[] = "A string\tof ,,tokens\nand some  more tokens";
char seps[]   = " ,\t\n";
char *token;

int main( void )
{
    printf( "Tokens:\n" );
    /* Establish string and get the first token: */
    token = strtok( string, seps );
    while( token != NULL )
    {
        /* While there are tokens in "string" */
        printf( " %s\n", token );
        /* Get next token: */
        token = strtok( NULL, seps );
    }
}