Programs & Examples On #Columnattribute

CSS3 Spin Animation

You haven't specified any keyframes. I made it work here.

div {
    margin: 20px;
    width: 100px; 
    height: 100px;    
    background: #f00;
    -webkit-animation: spin 4s infinite linear;
}

@-webkit-keyframes spin {
    0%  {-webkit-transform: rotate(0deg);}
    100% {-webkit-transform: rotate(360deg);}   
}

You can actually do lots of really cool stuff with this. Here is one I made earlier.

:)

N.B. You can skip having to write out all the prefixes if you use -prefix-free.

How can I declare and define multiple variables in one line using C++?

I wouldn't recommend this, but if you're really into it being one line and only writing 0 once, you can also do this:

int row, column, index = row = column = 0;

LF will be replaced by CRLF in git - What is that and is it important?

If you want, you can deactivate this feature in your git core config using

git config core.autocrlf false

But it would be better to just get rid of the warnings using

git config core.autocrlf true

How to remove certain characters from a string in C++?

Here's yet another alternative:

template<typename T>
void Remove( std::basic_string<T> & Str, const T * CharsToRemove )
{
    std::basic_string<T>::size_type pos = 0;
    while (( pos = Str.find_first_of( CharsToRemove, pos )) != std::basic_string<T>::npos )
    {
        Str.erase( pos, 1 ); 
    }
}

std::string a ("(555) 555-5555");
Remove( a, "()-");

Works with std::string and std::wstring

What is the difference between DAO and Repository patterns?

DAO is an abstraction of data persistence.
Repository is an abstraction of a collection of objects.

DAO would be considered closer to the database, often table-centric.
Repository would be considered closer to the Domain, dealing only in Aggregate Roots.

Repository could be implemented using DAO's, but you wouldn't do the opposite.

Also, a Repository is generally a narrower interface. It should be simply a collection of objects, with a Get(id), Find(ISpecification), Add(Entity).

A method like Update is appropriate on a DAO, but not a Repository - when using a Repository, changes to entities would usually be tracked by separate UnitOfWork.

It does seem common to see implementations called a Repository that is really more of a DAO, and hence I think there is some confusion about the difference between them.

How can I find all matches to a regular expression in Python?

Use re.findall or re.finditer instead.

re.findall(pattern, string) returns a list of matching strings.

re.finditer(pattern, string) returns an iterator over MatchObject objects.

Example:

re.findall( r'all (.*?) are', 'all cats are smarter than dogs, all dogs are dumber than cats')
# Output: ['cats', 'dogs']

[x.group() for x in re.finditer( r'all (.*?) are', 'all cats are smarter than dogs, all dogs are dumber than cats')]
# Output: ['all cats are', 'all dogs are']

Create a batch file to copy and rename file

Make a bat file with the following in it:

copy /y C:\temp\log1k.txt C:\temp\log1k_copied.txt

However, I think there are issues if there are spaces in your directory names. Notice this was copied to the same directory, but that doesn't matter. If you want to see how it runs, make another bat file that calls the first and outputs to a log:

C:\temp\test.bat > C:\temp\test.log

(assuming the first bat file was called test.bat and was located in that directory)

Can I run multiple programs in a Docker container?

They can be in separate containers, and indeed, if the application was also intended to run in a larger environment, they probably would be.

A multi-container system would require some more orchestration to be able to bring up all the required dependencies, though in Docker v0.6.5+, there is a new facility to help with that built into Docker itself - Linking. With a multi-machine solution, its still something that has to be arranged from outside the Docker environment however.

With two different containers, the two parts still communicate over TCP/IP, but unless the ports have been locked down specifically (not recommended, as you'd be unable to run more than one copy), you would have to pass the new port that the database has been exposed as to the application, so that it could communicate with Mongo. This is again, something that Linking can help with.

For a simpler, small installation, where all the dependencies are going in the same container, having both the database and Python runtime started by the program that is initially called as the ENTRYPOINT is also possible. This can be as simple as a shell script, or some other process controller - Supervisord is quite popular, and a number of examples exist in the public Dockerfiles.

What exactly does stringstream do?

You entered an alphanumeric and int, blank delimited in mystr.

You then tried to convert the first token (blank delimited) into an int.

The first token was RS which failed to convert to int, leaving a zero for myprice, and we all know what zero times anything yields.

When you only entered int values the second time, everything worked as you expected.

It was the spurious RS that caused your code to fail.

How to detect running app using ADB command

No need to use grep. ps in Android can filter by COMM value (last 15 characters of the package name in case of java app)

Let's say we want to check if com.android.phone is running:

adb shell ps m.android.phone
USER     PID   PPID  VSIZE  RSS     WCHAN    PC         NAME
radio     1389  277   515960 33964 ffffffff 4024c270 S com.android.phone

Filtering by COMM value option has been removed from ps in Android 7.0. To check for a running process by name in Android 7.0 you can use pidof command:

adb shell pidof com.android.phone

It returns the PID if such process was found or an empty string otherwise.

ERROR 1049 (42000): Unknown database

blog_development doesn't exist

You can see this in sql by the 0 rows affected message

create it in mysql with

mysql> create database blog_development

However as you are using rails you should get used to using

$ rake db:create

to do the same task. It will use your database.yml file settings, which should include something like:

development:
  adapter: mysql2
  database: blog_development
  pool: 5

Also become familiar with:

$ rake db:migrate  # Run the database migration
$ rake db:seed     # Run thew seeds file create statements
$ rake db:drop     # Drop the database

How do I update a model value in JavaScript in a Razor view?

This should work

function updatePostID(val)
{
    document.getElementById('PostID').value = val;

    //and probably call document.forms[0].submit();
}

Then have a hidden field or other control for the PostID

@Html.Hidden("PostID", Model.addcomment.PostID)
//OR
@Html.HiddenFor(model => model.addcomment.PostID)

What is the location of mysql client ".my.cnf" in XAMPP for Windows?

XAMPP uses a file called mysql_start.bat to start MySQL and if you open that file with a text editor you can see what config file is trying to use, in the current version it is:

mysql\bin\mysqld --defaults-file=mysql\bin\my.ini --standalone --console

If you installed XAMPP on the default path it means it is on c:/xampp/mysql/bin/my.ini


If somehow the file doesn't exist you should open a console terminal (start-> type "cmd", press enter) and then write "mysql --help" and it prints a text mentioning the default locations, in the current version of XAMPP is:

C:\Windows\my.ini C:\Windows\my.cnf C:\my.ini C:\my.cnf C:\xampp\mysql\my.ini C:\xampp\mysql\my.cnf

How to prevent custom views from losing state across screen orientation changes

Here is another variant that uses a mix of the two above methods. Combining the speed and correctness of Parcelable with the simplicity of a Bundle:

@Override
public Parcelable onSaveInstanceState() {
    Bundle bundle = new Bundle();
    // The vars you want to save - in this instance a string and a boolean
    String someString = "something";
    boolean someBoolean = true;
    State state = new State(super.onSaveInstanceState(), someString, someBoolean);
    bundle.putParcelable(State.STATE, state);
    return bundle;
}

@Override
public void onRestoreInstanceState(Parcelable state) {
    if (state instanceof Bundle) {
        Bundle bundle = (Bundle) state;
        State customViewState = (State) bundle.getParcelable(State.STATE);
        // The vars you saved - do whatever you want with them
        String someString = customViewState.getText();
        boolean someBoolean = customViewState.isSomethingShowing());
        super.onRestoreInstanceState(customViewState.getSuperState());
        return;
    }
    // Stops a bug with the wrong state being passed to the super
    super.onRestoreInstanceState(BaseSavedState.EMPTY_STATE); 
}

protected static class State extends BaseSavedState {
    protected static final String STATE = "YourCustomView.STATE";

    private final String someText;
    private final boolean somethingShowing;

    public State(Parcelable superState, String someText, boolean somethingShowing) {
        super(superState);
        this.someText = someText;
        this.somethingShowing = somethingShowing;
    }

    public String getText(){
        return this.someText;
    }

    public boolean isSomethingShowing(){
        return this.somethingShowing;
    }
}

C#: Limit the length of a string?

You could extend the "string" class to let you return a limited string.

using System;

namespace ConsoleApplication1
{
   class Program
   {
      static void Main(string[] args)
      {
         // since specified strings are treated on the fly as string objects...
         string limit5 = "The quick brown fox jumped over the lazy dog.".LimitLength(5);
         string limit10 = "The quick brown fox jumped over the lazy dog.".LimitLength(10);
         // this line should return us the entire contents of the test string
         string limit100 = "The quick brown fox jumped over the lazy dog.".LimitLength(100);

         Console.WriteLine("limit5   - {0}", limit5);
         Console.WriteLine("limit10  - {0}", limit10);
         Console.WriteLine("limit100 - {0}", limit100);

         Console.ReadLine();
      }
   }

   public static class StringExtensions
   {
      /// <summary>
      /// Method that limits the length of text to a defined length.
      /// </summary>
      /// <param name="source">The source text.</param>
      /// <param name="maxLength">The maximum limit of the string to return.</param>
      public static string LimitLength(this string source, int maxLength)
      {
         if (source.Length <= maxLength)
         {
            return source;
         }

         return source.Substring(0, maxLength);
      }
   }
}

Result:

limit5 - The q
limit10 - The quick
limit100 - The quick brown fox jumped over the lazy dog.

"Use the new keyword if hiding was intended" warning

The parent function needs the virtual keyword, and the child function needs the override keyword in front of the function definition.

How to display .svg image using swift

To render SVG file you can use Macaw. Also Macaw supports transformations, user events, animation and various effects.

You can render SVG file with zero lines of code. For more info please check this article: Render SVG file with Macaw.

DISCLAIMER: I am affiliated with this project.

SQL Server: Query fast, but slow from procedure

I had the same problem as the original poster but the quoted answer did not solve the problem for me. The query still ran really slow from a stored procedure.

I found another answer here "Parameter Sniffing", Thanks Omnibuzz. Boils down to using "local Variables" in your stored procedure queries, but read the original for more understanding, it's a great write up. e.g.

Slow way:

CREATE PROCEDURE GetOrderForCustomers(@CustID varchar(20))
AS
BEGIN
    SELECT * 
    FROM orders
    WHERE customerid = @CustID
END

Fast way:

CREATE PROCEDURE GetOrderForCustomersWithoutPS(@CustID varchar(20))
AS
BEGIN
    DECLARE @LocCustID varchar(20)
    SET @LocCustID = @CustID

    SELECT * 
    FROM orders
    WHERE customerid = @LocCustID
END

Hope this helps somebody else, doing this reduced my execution time from 5+ minutes to about 6-7 seconds.

What is the difference between DSA and RSA?

Btw, you cannot encrypt with DSA, only sign. Although they are mathematically equivalent (more or less) you cannot use DSA in practice as an encryption scheme, only as a digital signature scheme.

sqlplus error on select from external table: ORA-29913: error in executing ODCIEXTTABLEOPEN callout

We faced the same problem:

ORA-29913: error in executing ODCIEXTTABLEOPEN callout
ORA-29400: data cartridge error error opening file /fs01/app/rms01/external/logs/SH_EXT_TAB_VGAG_DELIV_SCHED.log

In our case we had a RAC with 2 nodes. After giving write permission on the log directory, on both sides, everything worked fine.

How do I compare a value to a backslash?

When you only need to check for equality, you can also simply use the in operator to do a membership test in a sequence of accepted elements:

if message.value[0] in ('/', '\\'):
    do_stuff()

Rename multiple files in cmd

I was puzzled by this also... didn't like the parentheses that windows puts in when you rename in bulk. In my research I decided to write a script with PowerShell instead. Super easy and worked like a charm. Now I can use it whenever I need to batch process file renaming... which is frequent. I take hundreds of photos and the camera names them IMG1234.JPG etc...

Here is the script I wrote:

# filename: bulk_file_rename.ps1
# by: subcan
# PowerShell script to rename multiple files within a folder to a 
# name that increments without (#)
# create counter
$int = 1
# ask user for what they want
$regex = Read-Host "Regex for files you are looking for? ex. IMG*.JPG "
$file_name = Read-Host "What is new file name, without extension? ex. New Image "
$extension = Read-Host "What extension do you want? ex. .JPG "
# get a total count of the files that meet regex
$total = Get-ChildItem -Filter $regex | measure
# while loop to rename all files with new name
while ($int -le $total.Count)
{
    # diplay where in loop you are
    Write-Host "within while loop" $int  
    # create variable for concatinated new name - 
    # $int.ToString(000) ensures 3 digit number 001, 010, etc
    $new_name = $file_name + $int.ToString(000)+$extension
    # get the first occurance and rename
    Get-ChildItem -Filter $regex | select -First 1 | Rename-Item -NewName $new_name
    # display renamed file name
    Write-Host "Renamed to" $new_name
    # increment counter
    $int++
}

I hope that this is helpful to someone out there.

subcan

Resolve build errors due to circular dependency amongst classes

I once solved this kind of problem by moving all inlines after the class definition and putting the #include for the other classes just before the inlines in the header file. This way one make sure all definitions+inlines are set prior the inlines are parsed.

Doing like this makes it possible to still have a bunch of inlines in both(or multiple) header files. But it's necessary to have include guards.

Like this

// File: A.h
#ifndef __A_H__
#define __A_H__
class B;
class A
{
    int _val;
    B *_b;
public:
    A(int val);
    void SetB(B *b);
    void Print();
};

// Including class B for inline usage here 
#include "B.h"

inline A::A(int val) : _val(val)
{
}

inline void A::SetB(B *b)
{
    _b = b;
    _b->Print();
}

inline void A::Print()
{
    cout<<"Type:A val="<<_val<<endl;
}

#endif /* __A_H__ */

...and doing the same in B.h

The model backing the <Database> context has changed since the database was created

After some research on this topic, I found that the error is occured basically if you have an instance of db created previously on your local sql server express. So whenever you have updates on db and try to update the db/run some code on db without running Update Database command using Package Manager Console; first of all, you have to delete previous db on our local sql express manually.

Also, this solution works unless you have AutomaticMigrationsEnabled = false;in your Configuration.

If you work with a version control system (git,svn,etc.) and some other developers update db objects in production phase then this error rises whenever you update your code base and run the application.

As stated above, there are some solutions for this on code base. However, this is the most practical one for some cases.

Remove space above and below <p> tag HTML

In case anyone wishes to do this with bootstrap, version 4 offers the following:

The classes are named using the format {property}{sides}-{size} for xs and {property}{sides}-{breakpoint}-{size} for sm, md, lg, and xl.

Where property is one of:

m - for classes that set margin
p - for classes that set padding

Where sides is one of:

t - for classes that set margin-top or padding-top
b - for classes that set margin-bottom or padding-bottom
l - for classes that set margin-left or padding-left
r - for classes that set margin-right or padding-right
x - for classes that set both *-left and *-right
y - for classes that set both *-top and *-bottom
blank - for classes that set a margin or padding on all 4 sides of the element

Where size is one of:

0 - for classes that eliminate the margin or padding by setting it to 0
1 - (by default) for classes that set the margin or padding to $spacer * .25
2 - (by default) for classes that set the margin or padding to $spacer * .5
3 - (by default) for classes that set the margin or padding to $spacer
4 - (by default) for classes that set the margin or padding to $spacer * 1.5
5 - (by default) for classes that set the margin or padding to $spacer * 3
auto - for classes that set the margin to auto

For example:

.mt-0 {
  margin-top: 0 !important;
}

.ml-1 {
  margin-left: ($spacer * .25) !important;
}

.px-2 {
  padding-left: ($spacer * .5) !important;
  padding-right: ($spacer * .5) !important;
}

.p-3 {
  padding: $spacer !important;
}

Reference: https://getbootstrap.com/docs/4.0/utilities/spacing/

How to evaluate a boolean variable in an if block in bash?

bash doesn't know boolean variables, nor does test (which is what gets called when you use [).

A solution would be:

if $myVar ; then ... ; fi

because true and false are commands that return 0 or 1 respectively which is what if expects.

Note that the values are "swapped". The command after if must return 0 on success while 0 means "false" in most programming languages.

SECURITY WARNING: This works because BASH expands the variable, then tries to execute the result as a command! Make sure the variable can't contain malicious code like rm -rf /

How to resolve TypeError: can only concatenate str (not "int") to str

Change secret_string += str(chr(char + 7429146))

To secret_string += chr(ord(char) + 7429146)

ord() converts the character to its Unicode integer equivalent. chr() then converts this integer into its Unicode character equivalent.

Also, 7429146 is too big of a number, it should be less than 1114111

Repeat table headers in print mode

Flying Saucer xhtmlrenderer repeats the THEAD on every page of PDF output, if you add the following to your CSS:

        table {
            -fs-table-paginate: paginate;
        }

(It works at least since the R8 release.)

How to get exact browser name and version?

  • There is a conflict between (Safari) and (Opera) and (Chrome) !!!

  • The above codes couldn't work properly

This is my code, and it works very well without any conflict:

function ExactBrowserName()
{

$ExactBrowserNameUA=$_SERVER['HTTP_USER_AGENT'];

if (strpos(strtolower($ExactBrowserNameUA), "safari/") and strpos(strtolower($ExactBrowserNameUA), "opr/")) {
    // OPERA
    $ExactBrowserNameBR="Opera";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "safari/") and strpos(strtolower($ExactBrowserNameUA), "chrome/")) {
    // CHROME
    $ExactBrowserNameBR="Chrome";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "msie")) {
    // INTERNET EXPLORER
    $ExactBrowserNameBR="Internet Explorer";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "firefox/")) {
    // FIREFOX
    $ExactBrowserNameBR="Firefox";
} elseIf (strpos(strtolower($ExactBrowserNameUA), "safari/") and strpos(strtolower($ExactBrowserNameUA), "opr/")==false and strpos(strtolower($ExactBrowserNameUA), "chrome/")==false) {
    // SAFARI
    $ExactBrowserNameBR="Safari";
} else {
    // OUT OF DATA
    $ExactBrowserNameBR="OUT OF DATA";
};

return $ExactBrowserNameBR;
}

How to dynamically insert a <script> tag via jQuery after page load?

You can put the script into a separate file, then use $.getScript to load and run it.

Example:

$.getScript("test.js", function(){
    alert("Running test.js");
});

How do I list all tables in all databases in SQL Server in a single result set?

please fill the @likeTablename param for search table.

now this parameter set to %tbltrans% for search all table contain tbltrans in name.

set @likeTablename to '%' to show all table.

declare @AllTableNames nvarchar(max);

select  @AllTableNames=STUFF((select ' SELECT  TABLE_CATALOG collate DATABASE_DEFAULT+''.''+TABLE_SCHEMA collate DATABASE_DEFAULT+''.''+TABLE_NAME collate DATABASE_DEFAULT as tablename FROM '+name+'.INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = ''BASE TABLE'' union '
 FROM master.sys.databases 
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)') 
,1,1,'');

set @AllTableNames=left(@AllTableNames,len(@AllTableNames)-6)

declare @likeTablename nvarchar(200)='%tbltrans%';
set @AllTableNames=N'select tablename from('+@AllTableNames+N')at where tablename like '''+N'%'+@likeTablename+N'%'+N''''
exec sp_executesql  @AllTableNames

Open a Web Page in a Windows Batch FIle

You can use the start command to do much the same thing as ShellExecute. For example

 start "" http://www.stackoverflow.com

This will launch whatever browser is the default browser, so won't necessarily launch Internet Explorer.

How to run function in AngularJS controller on document ready?

If you're getting something like getElementById call returns null, it's probably because the function is running, but the ID hasn't had time to load in the DOM.

Try using Will's answer (towards the top) with a delay. Example:

angular.module('MyApp', [])

.controller('MyCtrl', [function() {
    $scope.sleep = (time) => {
        return new Promise((resolve) => setTimeout(resolve, time));
    };
    angular.element(document).ready(function () {
        $scope.sleep(500).then(() => {        
            //code to run here after the delay
        });
    });
}]);

Controlling Spacing Between Table Cells

To get the job done, use

<table cellspacing=12>

If you’d rather “be right” than get things done, you can instead use the CSS property border-spacing, which is supported by some browsers.

How to make ng-repeat filter out duplicate results

This might be overkill, but it works for me.

Array.prototype.contains = function (item, prop) {
var arr = this.valueOf();
if (prop == undefined || prop == null) {
    for (var i = 0; i < arr.length; i++) {
        if (arr[i] == item) {
            return true;
        }
    }
}
else {
    for (var i = 0; i < arr.length; i++) {
        if (arr[i][prop] == item) return true;
    }
}
return false;
}

Array.prototype.distinct = function (prop) {
   var arr = this.valueOf();
   var ret = [];
   for (var i = 0; i < arr.length; i++) {
       if (!ret.contains(arr[i][prop], prop)) {
           ret.push(arr[i]);
       }
   }
   arr = [];
   arr = ret;
   return arr;
}

The distinct function depends on the contains function defined above. It can be called as array.distinct(prop); where prop is the property you want to be distinct.

So you could just say $scope.places.distinct("category");

git is not installed or not in the PATH

Did you install Git correctly?

According to the Bower site, you need to make sure you check the option "Run Git from Windows Command Prompt".

I had this issue where Git was not found when I was trying to install Angular. I re-ran the installer for git and changed my setting and then it worked.

enter image description here

From the bower site: http://bower.io/

Best way to store data locally in .NET (C#)

It depends on the amount of data you are looking to store. In reality there's no difference between flat files and XML. XML would probably be preferable since it provides a structure to the document. In practice,

The last option, and a lot of applications use now is the Windows Registry. I don't personally recommend it (Registry Bloat, Corruption, other potential issues), but it is an option.

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

The largest port number is an unsigned short 2^16-1: 65535

A registered port is one assigned by the Internet Corporation for Assigned Names and Numbers (ICANN) to a certain use. Each registered port is in the range 1024–49151.

Since 21 March 2001 the registry agency is ICANN; before that time it was IANA.

Ports with numbers lower than those of the registered ports are called well known ports; port with numbers greater than those of the registered ports are called dynamic and/or private ports.

Wikipedia : Registered Ports

Meaning of .Cells(.Rows.Count,"A").End(xlUp).row

It is used to find the how many rows contain data in a worksheet that contains data in the column "A". The full usage is

 lastRowIndex = ws.Cells(ws.Rows.Count, "A").End(xlUp).row

Where ws is a Worksheet object. In the questions example it was implied that the statement was inside a With block

With ws
    lastRowIndex = .Cells(.Rows.Count, "A").End(xlUp).row
End With
  1. ws.Rows.Count returns the total count of rows in the worksheet (1048576 in Excel 2010).
  2. .Cells(.Rows.Count, "A") returns the bottom most cell in column "A" in the worksheet

Then there is the End method. The documentation is ambiguous as to what it does.

Returns a Range object that represents the cell at the end of the region that contains the source range

Particularly it doesn't define what a "region" is. My understanding is a region is a contiguous range of non-empty cells. So the expected usage is to start from a cell in a region and find the last cell in that region in that direction from the original cell. However there are multiple exceptions for when you don't use it like that:

  • If the range is multiple cells, it will use the region of rng.cells(1,1).
  • If the range isn't in a region, or the range is already at the end of the region, then it will travel along the direction until it enters a region and return the first encountered cell in that region.
  • If it encounters the edge of the worksheet it will return the cell on the edge of that worksheet.

So Range.End is not a trivial function.

  1. .row returns the row index of that cell.

Reliable and fast FFT in Java

I wrote a function for the FFT in Java: http://www.wikijava.org/wiki/The_Fast_Fourier_Transform_in_Java_%28part_1%29

It's in the Public Domain so you can use those functions everywhere (personal or business projects too). Just cite me in the credits and send me just a link of your work, and you're ok.

It is completely reliable. I've checked its output against the Mathematica's FFT and they were always correct until the 15th decimal digit. I think it's a very good FFT implementation for Java. I wrote it on the J2SE 1.6 version, and tested it on the J2SE 1.5-1.6 version.

If you count the number of instruction (it's a lot much simpler than a perfect computational complexity function estimation) you can clearly see that this version is great even if it's not optimized at all. I'm planning to publish the optimized version if there are enough requests.

Let me know if it was useful, and tell me any comment you like.

I share the same code right here:

/**
* @author Orlando Selenu
*
*/
public class FFTbase {
/**
 * The Fast Fourier Transform (generic version, with NO optimizations).
 *
 * @param inputReal
 *            an array of length n, the real part
 * @param inputImag
 *            an array of length n, the imaginary part
 * @param DIRECT
 *            TRUE = direct transform, FALSE = inverse transform
 * @return a new array of length 2n
 */
public static double[] fft(final double[] inputReal, double[] inputImag,
                           boolean DIRECT) {
    // - n is the dimension of the problem
    // - nu is its logarithm in base e
    int n = inputReal.length;

    // If n is a power of 2, then ld is an integer (_without_ decimals)
    double ld = Math.log(n) / Math.log(2.0);

    // Here I check if n is a power of 2. If exist decimals in ld, I quit
    // from the function returning null.
    if (((int) ld) - ld != 0) {
        System.out.println("The number of elements is not a power of 2.");
        return null;
    }

    // Declaration and initialization of the variables
    // ld should be an integer, actually, so I don't lose any information in
    // the cast
    int nu = (int) ld;
    int n2 = n / 2;
    int nu1 = nu - 1;
    double[] xReal = new double[n];
    double[] xImag = new double[n];
    double tReal, tImag, p, arg, c, s;

    // Here I check if I'm going to do the direct transform or the inverse
    // transform.
    double constant;
    if (DIRECT)
        constant = -2 * Math.PI;
    else
        constant = 2 * Math.PI;

    // I don't want to overwrite the input arrays, so here I copy them. This
    // choice adds \Theta(2n) to the complexity.
    for (int i = 0; i < n; i++) {
        xReal[i] = inputReal[i];
        xImag[i] = inputImag[i];
    }

    // First phase - calculation
    int k = 0;
    for (int l = 1; l <= nu; l++) {
        while (k < n) {
            for (int i = 1; i <= n2; i++) {
                p = bitreverseReference(k >> nu1, nu);
                // direct FFT or inverse FFT
                arg = constant * p / n;
                c = Math.cos(arg);
                s = Math.sin(arg);
                tReal = xReal[k + n2] * c + xImag[k + n2] * s;
                tImag = xImag[k + n2] * c - xReal[k + n2] * s;
                xReal[k + n2] = xReal[k] - tReal;
                xImag[k + n2] = xImag[k] - tImag;
                xReal[k] += tReal;
                xImag[k] += tImag;
                k++;
            }
            k += n2;
        }
        k = 0;
        nu1--;
        n2 /= 2;
    }

    // Second phase - recombination
    k = 0;
    int r;
    while (k < n) {
        r = bitreverseReference(k, nu);
        if (r > k) {
            tReal = xReal[k];
            tImag = xImag[k];
            xReal[k] = xReal[r];
            xImag[k] = xImag[r];
            xReal[r] = tReal;
            xImag[r] = tImag;
        }
        k++;
    }

    // Here I have to mix xReal and xImag to have an array (yes, it should
    // be possible to do this stuff in the earlier parts of the code, but
    // it's here to readibility).
    double[] newArray = new double[xReal.length * 2];
    double radice = 1 / Math.sqrt(n);
    for (int i = 0; i < newArray.length; i += 2) {
        int i2 = i / 2;
        // I used Stephen Wolfram's Mathematica as a reference so I'm going
        // to normalize the output while I'm copying the elements.
        newArray[i] = xReal[i2] * radice;
        newArray[i + 1] = xImag[i2] * radice;
    }
    return newArray;
}

/**
 * The reference bitreverse function.
 */
private static int bitreverseReference(int j, int nu) {
    int j2;
    int j1 = j;
    int k = 0;
    for (int i = 1; i <= nu; i++) {
        j2 = j1 / 2;
        k = 2 * k + j1 - 2 * j2;
        j1 = j2;
    }
    return k;
  }
}

System.web.mvc missing

Add the reference again from ./packages/Microsoft.AspNet.Mvc.[version]/lib/net45/System.Web.Mvc.dll

String concatenation in Jinja

Just another hack can be like this.

I have Array of strings which I need to concatenate. So I added that array into dictionary and then used it inside for loop which worked.

{% set dict1 = {'e':''} %}
{% for i in list1 %}
{% if dict1.update({'e':dict1.e+":"+i+"/"+i}) %} {% endif %}
{% endfor %}
{% set layer_string = dict1['e'] %}

Can a main() method of class be invoked from another class in java

Sure. Here's a completely silly program that demonstrates calling main recursively.

public class main
{
    public static void main(String[] args)
    {
        for (int i = 0; i < args.length; ++i)
        {
            if (args[i] != "")
            {
                args[i] = "";
                System.out.println((args.length - i) + " left");
                main(args);
            }
        }

    }
}

How do I create a chart with multiple series using different X values for each series?

You need to use the Scatter chart type instead of Line. That will allow you to define separate X values for each series.

Get current domain

Simply try:

echo apache_request_headers()[3];

Getting the text that follows after the regex match

You just need to put "group(1)" instead of "group()" in the following line and the return will be the one you expected:

System.out.println("I found the text: " + matcher.group(**1**).toString());

Running Jupyter via command line on Windows

In Python 3.7.6 for Windows 10. After installation, I use these commands.

1. pip install notebook
2. python -m notebook

OR

C:\Users\Hamza\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.7_qbz5n2kfra8p0\LocalCache\local-packages\Python37\Scripts .

For my pc python-scripts are located in the above path. You can add this path in environment variables. Then run command.

1. jupyter notebook

Copying files from one directory to another in Java

If you don't want to use external libraries and you want to use the java.io instead of java.nio classes, you can use this concise method to copy a folder and all its content:

/**
 * Copies a folder and all its content to another folder. Do not include file separator at the end path of the folder destination.
 * @param folderToCopy The folder and it's content that will be copied
 * @param folderDestination The folder destination
 */
public static void copyFolder(File folderToCopy, File folderDestination) {
    if(!folderDestination.isDirectory() || !folderToCopy.isDirectory())
        throw new IllegalArgumentException("The folderToCopy and folderDestination must be directories");

    folderDestination.mkdirs();

    for(File fileToCopy : folderToCopy.listFiles()) {
        File copiedFile = new File(folderDestination + File.separator + fileToCopy.getName());

        try (FileInputStream fis = new FileInputStream(fileToCopy);
             FileOutputStream fos = new FileOutputStream(copiedFile)) {

            int read;
            byte[] buffer = new byte[512];

            while ((read = fis.read(buffer)) != -1) {
                fos.write(buffer, 0, read);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}

How to make rpm auto install dependencies

Step1: copy all the rpm pkg in given locations

Step2: if createrepo is not already installed, as it will not be by default, install it.

[root@pavangildamysql1 8.0.11_rhel7]# yum install createrepo

Step3: create repository metedata and give below permission

[root@pavangildamysql1 8.0.11_rhel7]# chown -R root.root /scratch/PVN/8.0.11_rhel7
[root@pavangildamysql1 8.0.11_rhel7]# createrepo /scratch/PVN/8.0.11_rhel7
Spawning worker 0 with 3 pkgs
Spawning worker 1 with 3 pkgs
Spawning worker 2 with 3 pkgs
Spawning worker 3 with 2 pkgs
Workers Finished
Saving Primary metadata
Saving file lists metadata
Saving other metadata
Generating sqlite DBs
Sqlite DBs complete
[root@pavangildamysql1 8.0.11_rhel7]# chmod -R o-w+r /scratch/PVN/8.0.11_rhel7

Step4: Create repository file with following contents at /etc/yum.repos.d/mysql.repo

[local]
name=My Awesome Repo
baseurl=file:///scratch/PVN/8.0.11_rhel7
enabled=1
gpgcheck=0

Step5 Run this command to install

[root@pavangildamysql1 local]# yum --nogpgcheck localinstall mysql-commercial-server-8.0.11-1.1.el7.x86_64.rpm

Python exit commands - why so many and when should each be used?

The functions* quit(), exit(), and sys.exit() function in the same way: they raise the SystemExit exception. So there is no real difference, except that sys.exit() is always available but exit() and quit() are only available if the site module is imported.

The os._exit() function is special, it exits immediately without calling any cleanup functions (it doesn't flush buffers, for example). This is designed for highly specialized use cases... basically, only in the child after an os.fork() call.

Conclusion

  • Use exit() or quit() in the REPL.

  • Use sys.exit() in scripts, or raise SystemExit() if you prefer.

  • Use os._exit() for child processes to exit after a call to os.fork().

All of these can be called without arguments, or you can specify the exit status, e.g., exit(1) or raise SystemExit(1) to exit with status 1. Note that portable programs are limited to exit status codes in the range 0-255, if you raise SystemExit(256) on many systems this will get truncated and your process will actually exit with status 0.

Footnotes

* Actually, quit() and exit() are callable instance objects, but I think it's okay to call them functions.

How to convert an IPv4 address into a integer in C#?

Assembled several of the above answers into an extension method that handles the Endianness of the machine and handles IPv4 addresses that were mapped to IPv6.

public static class IPAddressExtensions
{
    /// <summary>
    /// Converts IPv4 and IPv4 mapped to IPv6 addresses to an unsigned integer.
    /// </summary>
    /// <param name="address">The address to conver</param>
    /// <returns>An unsigned integer that represents an IPv4 address.</returns>
    public static uint ToUint(this IPAddress address)
    {
        if (address.AddressFamily == AddressFamily.InterNetwork || address.IsIPv4MappedToIPv6)
        {
            var bytes = address.GetAddressBytes();
            if (BitConverter.IsLittleEndian)
                Array.Reverse(bytes);

            return BitConverter.ToUInt32(bytes, 0);
        }
        throw new ArgumentOutOfRangeException("address", "Address must be IPv4 or IPv4 mapped to IPv6");
    }
}

Unit tests:

[TestClass]
public class IPAddressExtensionsTests
{
    [TestMethod]
    public void SimpleIp1()
    {
        var ip = IPAddress.Parse("0.0.0.15");
        uint expected = GetExpected(0, 0, 0, 15);
        Assert.AreEqual(expected, ip.ToUint());
    }
    [TestMethod]
    public void SimpleIp2()
    {
        var ip = IPAddress.Parse("0.0.1.15");
        uint expected = GetExpected(0, 0, 1, 15);
        Assert.AreEqual(expected, ip.ToUint());
    }
    [TestMethod]
    public void SimpleIpSix1()
    {
        var ip = IPAddress.Parse("0.0.0.15").MapToIPv6();
        uint expected = GetExpected(0, 0, 0, 15);
        Assert.AreEqual(expected, ip.ToUint());
    }
    [TestMethod]
    public void SimpleIpSix2()
    {
        var ip = IPAddress.Parse("0.0.1.15").MapToIPv6();
        uint expected = GetExpected(0, 0, 1, 15);
        Assert.AreEqual(expected, ip.ToUint());
    }
    [TestMethod]
    public void HighBits()
    {
        var ip = IPAddress.Parse("200.12.1.15").MapToIPv6();
        uint expected = GetExpected(200, 12, 1, 15);
        Assert.AreEqual(expected, ip.ToUint());
    }
    uint GetExpected(uint a, uint b, uint c, uint d)
    {
        return
            (a * 256u * 256u * 256u) +
            (b * 256u * 256u) +
            (c * 256u) +
            (d);
    }
}

Setting Authorization Header of HttpClient

6 Years later but adding this in case it helps someone.

https://www.codeproject.com/Tips/996401/Authenticate-WebAPIs-with-Basic-and-Windows-Authen

var authenticationBytes = Encoding.ASCII.GetBytes("<username>:<password>");
using (HttpClient confClient = new HttpClient())
{
  confClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", 
         Convert.ToBase64String(authenticationBytes));
  confClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(Constants.MediaType));  
  HttpResponseMessage message = confClient.GetAsync("<service URI>").Result;
  if (message.IsSuccessStatusCode)
  {
    var inter = message.Content.ReadAsStringAsync();
    List<string> result = JsonConvert.DeserializeObject<List<string>>(inter.Result);
  }
}

How to use npm with ASP.NET Core

I give you two answers. npm combined with other tools is powerful but requires some work to setup. If you just want to download some libraries, you might want to use Library Manager instead (released in Visual Studio 15.8).

NPM (Advanced)

First add package.json in the root of you project. Add the following content:

{
  "version": "1.0.0",
  "name": "asp.net",
  "private": true,
  "devDependencies": {
    "gulp": "3.9.1",
    "del": "3.0.0"
  },
  "dependencies": {
    "jquery": "3.3.1",
    "jquery-validation": "1.17.0",
    "jquery-validation-unobtrusive": "3.2.10",
    "bootstrap": "3.3.7"
  }
}

This will make NPM download Bootstrap, JQuery and other libraries that is used in a new asp.net core project to a folder named node_modules. Next step is to copy the files to an appropriate place. To do this we will use gulp, which also was downloaded by NPM. Then add a new file in the root of you project named gulpfile.js. Add the following content:

/// <binding AfterBuild='default' Clean='clean' />
/*
This file is the main entry point for defining Gulp tasks and using Gulp plugins.
Click here to learn more. http://go.microsoft.com/fwlink/?LinkId=518007
*/

var gulp = require('gulp');
var del = require('del');

var nodeRoot = './node_modules/';
var targetPath = './wwwroot/lib/';

gulp.task('clean', function () {
    return del([targetPath + '/**/*']);
});

gulp.task('default', function () {
    gulp.src(nodeRoot + "bootstrap/dist/js/*").pipe(gulp.dest(targetPath + "/bootstrap/dist/js"));
    gulp.src(nodeRoot + "bootstrap/dist/css/*").pipe(gulp.dest(targetPath + "/bootstrap/dist/css"));
    gulp.src(nodeRoot + "bootstrap/dist/fonts/*").pipe(gulp.dest(targetPath + "/bootstrap/dist/fonts"));

    gulp.src(nodeRoot + "jquery/dist/jquery.js").pipe(gulp.dest(targetPath + "/jquery/dist"));
    gulp.src(nodeRoot + "jquery/dist/jquery.min.js").pipe(gulp.dest(targetPath + "/jquery/dist"));
    gulp.src(nodeRoot + "jquery/dist/jquery.min.map").pipe(gulp.dest(targetPath + "/jquery/dist"));

    gulp.src(nodeRoot + "jquery-validation/dist/*.js").pipe(gulp.dest(targetPath + "/jquery-validation/dist"));

    gulp.src(nodeRoot + "jquery-validation-unobtrusive/dist/*.js").pipe(gulp.dest(targetPath + "/jquery-validation-unobtrusive"));
});

This file contains a JavaScript code that is executed when the project is build and cleaned. It’s will copy all necessary files to lib2 (not lib – you can easily change this). I have used the same structure as in a new project, but it’s easy to change files to a different location. If you move the files, make sure you also update _Layout.cshtml. Note that all files in the lib2-directory will be removed when the project is cleaned.

If you right click on gulpfile.js, you can select Task Runner Explorer. From here you can run gulp manually to copy or clean files.

Gulp could also be useful for other tasks like minify JavaScript and CSS-files:

https://docs.microsoft.com/en-us/aspnet/core/client-side/using-gulp?view=aspnetcore-2.1

Library Manager (Simple)

Right click on you project and select Manage client side-libraries. The file libman.json is now open. In this file you specify which library and files to use and where they should be stored locally. Really simple! The following file copies the default libraries that is used when creating a new ASP.NET Core 2.1 project:

{
  "version": "1.0",
  "defaultProvider": "cdnjs",
  "libraries": [
    {
      "library": "[email protected]",
      "files": [ "jquery.js", "jquery.min.map", "jquery.min.js" ],
      "destination": "wwwroot/lib/jquery/dist/"
    },
    {
      "library": "[email protected]",
      "files": [ "additional-methods.js", "additional-methods.min.js", "jquery.validate.js", "jquery.validate.min.js" ],
      "destination": "wwwroot/lib/jquery-validation/dist/"
    },
    {
      "library": "[email protected]",
      "files": [ "jquery.validate.unobtrusive.js", "jquery.validate.unobtrusive.min.js" ],
      "destination": "wwwroot/lib/jquery-validation-unobtrusive/"
    },
    {
      "library": "[email protected]",
      "files": [
        "css/bootstrap.css",
        "css/bootstrap.css.map",
        "css/bootstrap.min.css",
        "css/bootstrap.min.css.map",
        "css/bootstrap-theme.css",
        "css/bootstrap-theme.css.map",
        "css/bootstrap-theme.min.css",
        "css/bootstrap-theme.min.css.map",
        "fonts/glyphicons-halflings-regular.eot",
        "fonts/glyphicons-halflings-regular.svg",
        "fonts/glyphicons-halflings-regular.ttf",
        "fonts/glyphicons-halflings-regular.woff",
        "fonts/glyphicons-halflings-regular.woff2",
        "js/bootstrap.js",
        "js/bootstrap.min.js",
        "js/npm.js"
      ],
      "destination": "wwwroot/lib/bootstrap/dist"
    },
    {
      "library": "[email protected]",
      "files": [ "list.js", "list.min.js" ],
      "destination": "wwwroot/lib/listjs"
    }
  ]
}

If you move the files, make sure you also update _Layout.cshtml.

Why do I get a C malloc assertion failure?

i got the same problem, i used malloc over n over again in a loop for adding new char *string data. i faced the same problem, but after releasing the allocated memory void free() problem were sorted

Get textarea text with javascript or Jquery

Try This:

var info = document.getElementById("area1").value; // Javascript
var info = $("#area1").val(); // jQuery

Export specific rows from a PostgreSQL table as INSERT SQL script

I just knocked up a quick procedure to do this. It only works for a single row, so I create a temporary view that just selects the row I want, and then replace the pg_temp.temp_view with the actual table that I want to insert into.

CREATE OR REPLACE FUNCTION dv_util.gen_insert_statement(IN p_schema text, IN p_table text)
  RETURNS text AS
$BODY$
DECLARE
    selquery text; 
    valquery text; 
    selvalue text; 
    colvalue text; 
    colrec record;
BEGIN

    selquery := 'INSERT INTO ' ||  quote_ident(p_schema) || '.' || quote_ident(p_table);

    selquery := selquery || '(';

    valquery := ' VALUES (';
    FOR colrec IN SELECT table_schema, table_name, column_name, data_type
                  FROM information_schema.columns 
                  WHERE table_name = p_table and table_schema = p_schema 
                  ORDER BY ordinal_position 
    LOOP
      selquery := selquery || quote_ident(colrec.column_name) || ',';

      selvalue := 
        'SELECT CASE WHEN ' || quote_ident(colrec.column_name) || ' IS NULL' || 
                   ' THEN ''NULL''' || 
                   ' ELSE '''' || quote_literal('|| quote_ident(colrec.column_name) || ')::text || ''''' || 
                   ' END' || 
        ' FROM '||quote_ident(p_schema)||'.'||quote_ident(p_table);
      EXECUTE selvalue INTO colvalue;
      valquery := valquery || colvalue || ',';
    END LOOP;
    -- Replace the last , with a )
    selquery := substring(selquery,1,length(selquery)-1) || ')';
    valquery := substring(valquery,1,length(valquery)-1) || ')';

    selquery := selquery || valquery;

RETURN selquery;
END
$BODY$
  LANGUAGE plpgsql VOLATILE;

Invoked thus:

SELECT distinct dv_util.gen_insert_statement('pg_temp_' || sess_id::text,'my_data') 
from pg_stat_activity 
where procpid = pg_backend_pid()

I haven't tested this against injection attacks, please let me know if the quote_literal call isn't sufficient for that.

Also it only works for columns that can be simply cast to ::text and back again.

Also this is for Greenplum but I can't think of a reason why it wouldn't work on Postgres, CMIIW.

Getting list of pixel values from PIL

data = numpy.asarray(im)

Notice:In PIL, img is RGBA. In cv2, img is BGRA.

My robust solution:

def cv_from_pil_img(pil_img):
    assert pil_img.mode=="RGBA"
    return cv2.cvtColor(np.array(pil_img), cv2.COLOR_RGBA2BGRA)

How to do constructor chaining in C#

I just want to bring up a valid point to anyone searching for this. If you are going to work with .NET versions before 4.0 (VS2010), please be advised that you have to create constructor chains as shown above.

However, if you're staying in 4.0, I have good news. You can now have a single constructor with optional arguments! I'll simplify the Foo class example:

class Foo {
  private int id;
  private string name;

  public Foo(int id = 0, string name = "") {
    this.id = id;
    this.name = name;
  }
}

class Main() {
  // Foo Int:
  Foo myFooOne = new Foo(12);
  // Foo String:
  Foo myFooTwo = new Foo(name:"Timothy");
  // Foo Both:
  Foo myFooThree = new Foo(13, name:"Monkey");
}

When you implement the constructor, you can use the optional arguments since defaults have been set.

I hope you enjoyed this lesson! I just can't believe that developers have been complaining about construct chaining and not being able to use default optional arguments since 2004/2005! Now it has taken SO long in the development world, that developers are afraid of using it because it won't be backwards compatible.

Is it possible to disable the network in iOS Simulator?

You could use OHHTTPStubs and stub the network requests to specific URLs to fail.

New lines (\r\n) are not working in email body

"\n\r" produces 2 new lines while "\n","\r" & "\r\n" produce single lines if, in the Header, you use content-type: text/plain.

Beware: If you do the Following php code:

    $message='ab<br>cd<br>e<br>f';
print $message.'<br><br>';
    $message=str_replace('<br>',"\r\n",$message);
print $message;

you get the following in the Windows browser:

ab
cd
e
f

ab cd e f

and with content-type: text/plain you get the following in an email output;

ab
cd
e
f

How to inject Javascript in WebBrowser control?

What you want to do is use Page.RegisterStartupScript(key, script) :

See here for more details: http://msdn.microsoft.com/en-us/library/aa478975.aspx

What you basically do is build your javascript string, pass it to that method and give it a unique id( in case you try to register it twice on a page.)

EDIT: This is what you call trigger happy. Feel free to down it. :)

How to filter array when object key value is in array

Fastest way (will take extra memory):

var empid=[1,4,5]
var records = [{ "empid": 1, "fname": "X", "lname": "Y" }, { "empid": 2, "fname": "A", "lname": "Y" }, { "empid": 3, "fname": "B", "lname": "Y" }, { "empid": 4, "fname": "C", "lname": "Y" }, { "empid": 5, "fname": "C", "lname": "Y" }] ;

var empIdObj={};

empid.forEach(function(element) {
empIdObj[element]=true;
});

var filteredArray=[];

records.forEach(function(element) {
if(empIdObj[element.empid])
    filteredArray.push(element)
});

Generic deep diff between two objects

I stumbled here trying to look for a way to get the difference between two objects. This is my solution using Lodash:

// Get updated values (including new values)
var updatedValuesIncl = _.omitBy(curr, (value, key) => _.isEqual(last[key], value));

// Get updated values (excluding new values)
var updatedValuesExcl = _.omitBy(curr, (value, key) => (!_.has(last, key) || _.isEqual(last[key], value)));

// Get old values (by using updated values)
var oldValues = Object.keys(updatedValuesIncl).reduce((acc, key) => { acc[key] = last[key]; return acc; }, {});

// Get newly added values
var newCreatedValues = _.omitBy(curr, (value, key) => _.has(last, key));

// Get removed values
var deletedValues = _.omitBy(last, (value, key) => _.has(curr, key));

// Then you can group them however you want with the result

Code snippet below:

_x000D_
_x000D_
var last = {_x000D_
"authed": true,_x000D_
"inForeground": true,_x000D_
"goodConnection": false,_x000D_
"inExecutionMode": false,_x000D_
"online": true,_x000D_
"array": [1, 2, 3],_x000D_
"deep": {_x000D_
 "nested": "value",_x000D_
},_x000D_
"removed": "value",_x000D_
};_x000D_
_x000D_
var curr = {_x000D_
"authed": true,_x000D_
"inForeground": true,_x000D_
"deep": {_x000D_
 "nested": "changed",_x000D_
},_x000D_
"array": [1, 2, 4],_x000D_
"goodConnection": true,_x000D_
"inExecutionMode": false,_x000D_
"online": false,_x000D_
"new": "value"_x000D_
};_x000D_
_x000D_
// Get updated values (including new values)_x000D_
var updatedValuesIncl = _.omitBy(curr, (value, key) => _.isEqual(last[key], value));_x000D_
// Get updated values (excluding new values)_x000D_
var updatedValuesExcl = _.omitBy(curr, (value, key) => (!_.has(last, key) || _.isEqual(last[key], value)));_x000D_
// Get old values (by using updated values)_x000D_
var oldValues = Object.keys(updatedValuesIncl).reduce((acc, key) => { acc[key] = last[key]; return acc; }, {});_x000D_
// Get newly added values_x000D_
var newCreatedValues = _.omitBy(curr, (value, key) => _.has(last, key));_x000D_
// Get removed values_x000D_
var deletedValues = _.omitBy(last, (value, key) => _.has(curr, key));_x000D_
_x000D_
console.log('oldValues', JSON.stringify(oldValues));_x000D_
console.log('updatedValuesIncl', JSON.stringify(updatedValuesIncl));_x000D_
console.log('updatedValuesExcl', JSON.stringify(updatedValuesExcl));_x000D_
console.log('newCreatedValues', JSON.stringify(newCreatedValues));_x000D_
console.log('deletedValues', JSON.stringify(deletedValues));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>
_x000D_
_x000D_
_x000D_

RegEx for matching UK Postcodes

I had a look into some of the answers above and I'd recommend against using the pattern from @Dan's answer (c. Dec 15 '10), since it incorrectly flags almost 0.4% of valid postcodes as invalid, while the others do not.

Ordnance Survey provide service called Code Point Open which:

contains a list of all the current postcode units in Great Britain

I ran each of the regexs above against the full list of postcodes (Jul 6 '13) from this data using grep:

cat CSV/*.csv |
    # Strip leading quotes
    sed -e 's/^"//g' |
    # Strip trailing quote and everything after it
    sed -e 's/".*//g' |
    # Strip any spaces
    sed -E -e 's/ +//g' |
    # Find any lines that do not match the expression
    grep --invert-match --perl-regexp "$pattern"

There are 1,686,202 postcodes total.

The following are the numbers of valid postcodes that do not match each $pattern:

'^([A-PR-UWYZ0-9][A-HK-Y0-9][AEHMNPRTVXY0-9]?[ABEHMNPRVWXY0-9]?[0-9][ABD-HJLN-UW-Z]{2}|GIR 0AA)$'
# => 6016 (0.36%)
'^(GIR ?0AA|[A-PR-UWYZ]([0-9]{1,2}|([A-HK-Y][0-9]([0-9ABEHMNPRV-Y])?)|[0-9][A-HJKPS-UW]) ?[0-9][ABD-HJLNP-UW-Z]{2})$'
# => 0
'^GIR[ ]?0AA|((AB|AL|B|BA|BB|BD|BH|BL|BN|BR|BS|BT|BX|CA|CB|CF|CH|CM|CO|CR|CT|CV|CW|DA|DD|DE|DG|DH|DL|DN|DT|DY|E|EC|EH|EN|EX|FK|FY|G|GL|GY|GU|HA|HD|HG|HP|HR|HS|HU|HX|IG|IM|IP|IV|JE|KA|KT|KW|KY|L|LA|LD|LE|LL|LN|LS|LU|M|ME|MK|ML|N|NE|NG|NN|NP|NR|NW|OL|OX|PA|PE|PH|PL|PO|PR|RG|RH|RM|S|SA|SE|SG|SK|SL|SM|SN|SO|SP|SR|SS|ST|SW|SY|TA|TD|TF|TN|TQ|TR|TS|TW|UB|W|WA|WC|WD|WF|WN|WR|WS|WV|YO|ZE)(\d[\dA-Z]?[ ]?\d[ABD-HJLN-UW-Z]{2}))|BFPO[ ]?\d{1,4}$'
# => 0

Of course, these results only deal with valid postcodes that are incorrectly flagged as invalid. So:

'^.*$'
# => 0

I'm saying nothing about which pattern is the best regarding filtering out invalid postcodes.

Append a dictionary to a dictionary

Assuming that you do not want to change orig, you can either do a copy and update like the other answers, or you can create a new dictionary in one step by passing all items from both dictionaries into the dict constructor:

from itertools import chain
dest = dict(chain(orig.items(), extra.items()))

Or without itertools:

dest = dict(list(orig.items()) + list(extra.items()))

Note that you only need to pass the result of items() into list() on Python 3, on 2.x dict.items() already returns a list so you can just do dict(orig.items() + extra.items()).

As a more general use case, say you have a larger list of dicts that you want to combine into a single dict, you could do something like this:

from itertools import chain
dest = dict(chain.from_iterable(map(dict.items, list_of_dicts)))

javascript if number greater than number

You're comparing strings. JavaScript compares the ASCII code for each character of the string.

To see why you get false, look at the charCodes:

"1300".charCodeAt(0);
49
"999".charCodeAt(0);
57

The comparison is false because, when comparing the strings, the character codes for 1 is not greater than that of 9.

The fix is to treat the strings as numbers. You can use a number of methods:

parseInt(string, radix)
parseInt("1300", 10);
> 1300 - notice the lack of quotes


+"1300"
> 1300


Number("1300")
> 1300

How to fix Hibernate LazyInitializationException: failed to lazily initialize a collection of roles, could not initialize proxy - no Session

First of all I'd like to say that all users who said about lazy and transactions were right. But in my case there was a slight difference in that I used result of @Transactional method in a test and that was outside real transaction so I got this lazy exception.

My service method:

@Transactional
User get(String uid) {};

My test code:

User user = userService.get("123");
user.getActors(); //org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role

My solution to this was wrapping that code in another transaction like this:

List<Actor> actors = new ArrayList<>();
transactionTemplate.execute((status) 
 -> actors.addAll(userService.get("123").getActors()));

How to add an image to the emulator gallery in android studio?

I had the same problem too. I used this code:

Intent photoPickerIntent = new Intent(Intent.ACTION_GET_CONTENT);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, SELECT_PHOTO);

Using the ADM, add the images on the sdcard or anywhere.

And when you are in your vm and the selection screen shows up, browse using the top left dropdown seen in the image below.

look at 'open from'

Invoke(Delegate)

The answer to this question lies in how C# Controls work

Controls in Windows Forms are bound to a specific thread and are not thread safe. Therefore, if you are calling a control's method from a different thread, you must use one of the control's invoke methods to marshal the call to the proper thread. This property can be used to determine if you must call an invoke method, which can be useful if you do not know what thread owns a control.

From Control.InvokeRequired

Effectively, what Invoke does is ensure that the code you are calling occurs on the thread that the control "lives on" effectively preventing cross threaded exceptions.

From a historical perspective, in .Net 1.1, this was actually allowed. What it meant is that you could try and execute code on the "GUI" thread from any background thread and this would mostly work. Sometimes it would just cause your app to exit because you were effectively interrupting the GUI thread while it was doing something else. This is the Cross Threaded Exception - imagine trying to update a TextBox while the GUI is painting something else.

  • Which action takes priority?
  • Is it even possible for both to happen at once?
  • What happens to all of the other commands the GUI needs to run?

Effectively, you are interrupting a queue, which can have lots of unforeseen consequences. Invoke is effectively the "polite" way of getting what you want to do into that queue, and this rule was enforced from .Net 2.0 onward via a thrown InvalidOperationException.

To understand what is actually going on behind the scenes, and what is meant by "GUI Thread", it's useful to understand what a Message Pump or Message Loop is.

This is actually already answered in the question "What is a Message Pump" and is recommended reading for understanding the actual mechanism that you are tying into when interacting with controls.

Other reading you may find useful includes:

What's up with Begin Invoke

One of the cardinal rules of Windows GUI programming is that only the thread that created a control can access and/or modify its contents (except for a few documented exceptions). Try doing it from any other thread and you'll get unpredictable behavior ranging from deadlock, to exceptions to a half updated UI. The right way then to update a control from another thread is to post an appropriate message to the application message queue. When the message pump gets around to executing that message, the control will get updated, on the same thread that created it (remember, the message pump runs on the main thread).

and, for a more code heavy overview with a representative sample:

Invalid Cross-thread Operations

// the canonical form (C# consumer)

public delegate void ControlStringConsumer(Control control, string text);  // defines a delegate type

public void SetText(Control control, string text) {
    if (control.InvokeRequired) {
        control.Invoke(new ControlStringConsumer(SetText), new object[]{control, text});  // invoking itself
    } else {
        control.Text=text;      // the "functional part", executing only on the main thread
    }
}

Once you have an appreciation for InvokeRequired, you may wish to consider using an extension method for wrapping these calls up. This is ably covered in the Stack Overflow question Cleaning Up Code Littered with Invoke Required.

There is also a further write up of what happened historically that may be of interest.

Could not find a part of the path ... bin\roslyn\csc.exe

The problem with the default VS2015 templates is that the compiler isn't actually copied to the {outdir}_PublishedWebsites\tfr\bin\roslyn\ directory, but rather the {outdir}\roslyn\ directory. This is likely different from your local environment since AppHarbor builds apps using an output directory instead of building the solution "in-place".

To fix it, add the following towards end of .csproj file right after xml block <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">...</Target>

<PropertyGroup>
  <PostBuildEvent>
    if not exist "$(WebProjectOutputDir)\bin\Roslyn" md "$(WebProjectOutputDir)\bin\Roslyn"
    start /MIN xcopy /s /y /R "$(OutDir)roslyn\*.*" "$(WebProjectOutputDir)\bin\Roslyn"
  </PostBuildEvent>
</PropertyGroup>

Reference: https://support.appharbor.com/discussions/problems/78633-cant-build-aspnet-mvc-project-generated-from-vstudio-2015-enterprise

There can be only one auto column

CREATE TABLE book (
   id INT AUTO_INCREMENT primary key NOT NULL,
   accepted_terms BIT(1) NOT NULL,
   accepted_privacy BIT(1) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1

Invalid date in safari

I am also facing the same problem in Safari Browser

var date = new Date("2011-02-07");
console.log(date) // IE you get ‘NaN’ returned and in Safari you get ‘Invalid Date’

Here the solution:

var d = new Date(2011, 01, 07); // yyyy, mm-1, dd  
var d = new Date(2011, 01, 07, 11, 05, 00); // yyyy, mm-1, dd, hh, mm, ss  
var d = new Date("02/07/2011"); // "mm/dd/yyyy"  
var d = new Date("02/07/2011 11:05:00"); // "mm/dd/yyyy hh:mm:ss"  
var d = new Date(1297076700000); // milliseconds  
var d = new Date("Mon Feb 07 2011 11:05:00 GMT"); // ""Day Mon dd yyyy hh:mm:ss GMT/UTC 

Illegal mix of collations MySQL Error

My user account did not have the permissions to alter the database and table, as suggested in this solution.

If, like me, you don't care about the character collation (you are using the '=' operator), you can apply the reverse fix. Run this before your SELECT:

SET collation_connection = 'latin1_swedish_ci';

Unzipping files in Python

If you want to do it in shell, instead of writing code.

 python3 -m zipfile -e myfiles.zip myfiles/

myfiles.zip is the zip archive and myfiles is the path to extract the files.

DISABLE the Horizontal Scroll

Try adding this to your CSS

html, body {
    max-width: 100%;
    overflow-x: hidden;
}

Console app arguments, how arguments are passed to Main method

How is main called?

When you are using the console application template the code will be compiled requiring a method called Main in the startup object as Main is market as entry point to the application.

By default no startup object is specified in the project propery settings and the Program class will be used by default. You can change this in the project property under the "Build" tab if you wish.

Keep in mind that which ever object you assign to be the startup object must have a method named Main in it.

How are args passed to main method

The accepted format is MyConsoleApp.exe value01 value02 etc...

The application assigns each value after each space into a separate element of the parameter array.

Thus, MyConsoleApp.exe value01 value02 will mean your args paramter has 2 elements:

[0] = "value01"

[1] = "value02"

How you parse the input values and use them is up to you.

Hope this helped.

Additional Reading:

Creating Console Applications (Visual C#)

Command-Line Arguments (C# Programming Guide)

how to use html2canvas and jspdf to export to pdf in a proper and simple way

Changing this line:

var doc = new jsPDF('L', 'px', [w, h]);
var doc = new jsPDF('L', 'pt', [w, h]);

To fix the dimensions.

What is the difference between signed and unsigned variables?

Signed variables use one bit to flag whether they are positive or negative. Unsigned variables don't have this bit, so they can store larger numbers in the same space, but only nonnegative numbers, e.g. 0 and higher.

For more: Unsigned and Signed Integers

Run a php app using tomcat?

There this PHP/Java bridge. This is basically running PHP via FastCGI. I have not used it myself.

Angular 5 ngHide ngShow [hidden] not working

If you can not use *ngif, [class.hide] works in angular 7. example:

<mat-select (selectionChange)="changeFilter($event.value)" multiple [(ngModel)]="selected">
          <mat-option *ngFor="let filter of gridOptions.columnDefs"
                      [class.hide]="filter.headerName=='Action'"  [value]="filter.field">{{filter.headerName}}</mat-option>
        </mat-select>

Gradle project refresh failed after Android Studio update

  1. Close Android Studio
  2. Go to C:\Users\Username
  3. delete the .gradle folder

That's it you are done

Push JSON Objects to array in localStorage

As of now, you can only store string values in localStorage. You'll need to serialize the array object and then store it in localStorage.

For example:

localStorage.setItem('session', a.join('|'));

or

localStorage.setItem('session', JSON.stringify(a));

How to get all child inputs of a div element (jQuery)

If you are using a framework like Ruby on Rails or Spring MVC you may need to use divs with square braces or other chars, that are not allowed you can use document.getElementById and this solution still works if you have multiple inputs with the same type.

var div = document.getElementById(divID);
$(div).find('input:text, input:password, input:file, select, textarea')
        .each(function() {
            $(this).val('');
        });
$(div).find('input:radio, input:checkbox').each(function() {
    $(this).removeAttr('checked');
    $(this).removeAttr('selected');
});

This examples shows how to clear the inputs, for you example you'll need to change it.

addEventListener vs onclick

Summary:

  1. addEventListener can add multiple events, whereas with onclick this cannot be done.
  2. onclick can be added as an HTML attribute, whereas an addEventListener can only be added within <script> elements.
  3. addEventListener can take a third argument which can stop the event propagation.

Both can be used to handle events. However, addEventListener should be the preferred choice since it can do everything onclick does and more. Don't use inline onclick as HTML attributes as this mixes up the javascript and the HTML which is a bad practice. It makes the code less maintainable.

SSH Key: “Permissions 0644 for 'id_rsa.pub' are too open.” on mac

Key should be readable by the logged in user.

Try this:

chmod 400 ~/.ssh/Key file
chmod 400 ~/.ssh/vm_id_rsa.pub

show/hide a div on hover and hover out

Why not just use .show()/.hide() instead?

$("#menu").hover(function(){
    $('.flyout').show();
},function(){
    $('.flyout').hide();
});

Git conflict markers

The line (or lines) between the lines beginning <<<<<<< and ====== here:

<<<<<<< HEAD:file.txt
Hello world
=======

... is what you already had locally - you can tell because HEAD points to your current branch or commit. The line (or lines) between the lines beginning ======= and >>>>>>>:

=======
Goodbye
>>>>>>> 77976da35a11db4580b80ae27e8d65caf5208086:file.txt

... is what was introduced by the other (pulled) commit, in this case 77976da35a11. That is the object name (or "hash", "SHA1sum", etc.) of the commit that was merged into HEAD. All objects in git, whether they're commits (version), blobs (files), trees (directories) or tags have such an object name, which identifies them uniquely based on their content.

Searching multiple files for multiple words

If you are using Notepad++ editor (like the tag of the question suggests), you can use the great "Find in Files" functionality.

Go to Search > Find in Files (Ctrl+Shift+F for the keyboard addicted) and enter:

  • Find What = (test1|test2)
  • Filters = *.txt
  • Directory = enter the path of the directory you want to search in. You can check Follow current doc. to have the path of the current file to be filled.
  • Search mode = Regular Expression

Convert ArrayList to String array in Android

You could make an array the same size as the ArrayList and then make an iterated for loop to index the items and insert them into the array.

Git push requires username and password

Permanently authenticating with Git repositories

Run the following command to enable credential caching:

$ git config credential.helper store
$ git push https://github.com/owner/repo.git

Username for 'https://github.com': <USERNAME>
Password for 'https://[email protected]': <PASSWORD>

You should also specify caching expire,

git config --global credential.helper 'cache --timeout 7200'

After enabling credential caching, it will be cached for 7200 seconds (2 hour).

C++ unordered_map using a custom class type as the key

To be able to use std::unordered_map (or one of the other unordered associative containers) with a user-defined key-type, you need to define two things:

  1. A hash function; this must be a class that overrides operator() and calculates the hash value given an object of the key-type. One particularly straight-forward way of doing this is to specialize the std::hash template for your key-type.

  2. A comparison function for equality; this is required because the hash cannot rely on the fact that the hash function will always provide a unique hash value for every distinct key (i.e., it needs to be able to deal with collisions), so it needs a way to compare two given keys for an exact match. You can implement this either as a class that overrides operator(), or as a specialization of std::equal, or – easiest of all – by overloading operator==() for your key type (as you did already).

The difficulty with the hash function is that if your key type consists of several members, you will usually have the hash function calculate hash values for the individual members, and then somehow combine them into one hash value for the entire object. For good performance (i.e., few collisions) you should think carefully about how to combine the individual hash values to ensure you avoid getting the same output for different objects too often.

A fairly good starting point for a hash function is one that uses bit shifting and bitwise XOR to combine the individual hash values. For example, assuming a key-type like this:

struct Key
{
  std::string first;
  std::string second;
  int         third;

  bool operator==(const Key &other) const
  { return (first == other.first
            && second == other.second
            && third == other.third);
  }
};

Here is a simple hash function (adapted from the one used in the cppreference example for user-defined hash functions):

namespace std {

  template <>
  struct hash<Key>
  {
    std::size_t operator()(const Key& k) const
    {
      using std::size_t;
      using std::hash;
      using std::string;

      // Compute individual hash values for first,
      // second and third and combine them using XOR
      // and bit shifting:

      return ((hash<string>()(k.first)
               ^ (hash<string>()(k.second) << 1)) >> 1)
               ^ (hash<int>()(k.third) << 1);
    }
  };

}

With this in place, you can instantiate a std::unordered_map for the key-type:

int main()
{
  std::unordered_map<Key,std::string> m6 = {
    { {"John", "Doe", 12}, "example"},
    { {"Mary", "Sue", 21}, "another"}
  };
}

It will automatically use std::hash<Key> as defined above for the hash value calculations, and the operator== defined as member function of Key for equality checks.

If you don't want to specialize template inside the std namespace (although it's perfectly legal in this case), you can define the hash function as a separate class and add it to the template argument list for the map:

struct KeyHasher
{
  std::size_t operator()(const Key& k) const
  {
    using std::size_t;
    using std::hash;
    using std::string;

    return ((hash<string>()(k.first)
             ^ (hash<string>()(k.second) << 1)) >> 1)
             ^ (hash<int>()(k.third) << 1);
  }
};

int main()
{
  std::unordered_map<Key,std::string,KeyHasher> m6 = {
    { {"John", "Doe", 12}, "example"},
    { {"Mary", "Sue", 21}, "another"}
  };
}

How to define a better hash function? As said above, defining a good hash function is important to avoid collisions and get good performance. For a real good one you need to take into account the distribution of possible values of all fields and define a hash function that projects that distribution to a space of possible results as wide and evenly distributed as possible.

This can be difficult; the XOR/bit-shifting method above is probably not a bad start. For a slightly better start, you may use the hash_value and hash_combine function template from the Boost library. The former acts in a similar way as std::hash for standard types (recently also including tuples and other useful standard types); the latter helps you combine individual hash values into one. Here is a rewrite of the hash function that uses the Boost helper functions:

#include <boost/functional/hash.hpp>

struct KeyHasher
{
  std::size_t operator()(const Key& k) const
  {
      using boost::hash_value;
      using boost::hash_combine;

      // Start with a hash value of 0    .
      std::size_t seed = 0;

      // Modify 'seed' by XORing and bit-shifting in
      // one member of 'Key' after the other:
      hash_combine(seed,hash_value(k.first));
      hash_combine(seed,hash_value(k.second));
      hash_combine(seed,hash_value(k.third));

      // Return the result.
      return seed;
  }
};

And here’s a rewrite that doesn’t use boost, yet uses good method of combining the hashes:

namespace std
{
    template <>
    struct hash<Key>
    {
        size_t operator()( const Key& k ) const
        {
            // Compute individual hash values for first, second and third
            // http://stackoverflow.com/a/1646913/126995
            size_t res = 17;
            res = res * 31 + hash<string>()( k.first );
            res = res * 31 + hash<string>()( k.second );
            res = res * 31 + hash<int>()( k.third );
            return res;
        }
    };
}

Force Java timezone as GMT/UTC

Also if you can set JVM timezone this way

System.setProperty("user.timezone", "EST");

or -Duser.timezone=GMT in the JVM args.

How can I switch word wrap on and off in Visual Studio Code?

For Dart check "Line length" property in Settings.

AngularJS: factory $http.get JSON file

++ This worked for me. It's vanilla javascirpt and good for use cases such as de-cluttering when testing with ngMocks library:

<!-- specRunner.html - keep this at the top of your <script> asset loading so that it is available readily -->
<!--  Frienly tip - have all JSON files in a json-data folder for keeping things organized-->
<script src="json-data/findByIdResults.js" charset="utf-8"></script>
<script src="json-data/movieResults.js" charset="utf-8"></script>

This is your javascript file that contains the JSON data

// json-data/JSONFindByIdResults.js
var JSONFindByIdResults = {
     "Title": "Star Wars",
     "Year": "1983",
     "Rated": "N/A",
     "Released": "01 May 1983",
     "Runtime": "N/A",
     "Genre": "Action, Adventure, Sci-Fi",
     "Director": "N/A",
     "Writer": "N/A",
     "Actors": "Harrison Ford, Alec Guinness, Mark Hamill, James Earl Jones",
     "Plot": "N/A",
     "Language": "English",
     "Country": "USA",
     "Awards": "N/A",
     "Poster": "N/A",
     "Metascore": "N/A",
     "imdbRating": "7.9",
     "imdbVotes": "342",
     "imdbID": "tt0251413",
     "Type": "game",
     "Response": "True"
};

Finally, work with the JSON data anywhere in your code

// working with JSON data in code
var findByIdResults = window.JSONFindByIdResults;

Note:- This is great for testing and even karma.conf.js accepts these files for running tests as seen below. Also, I recommend this only for de-cluttering data and testing/development environment.

// extract from karma.conf.js
files: [
     'json-data/JSONSearchResultHardcodedData.js',
     'json-data/JSONFindByIdResults.js'
     ...
]

Hope this helps.

++ Built on top of this answer https://stackoverflow.com/a/24378510/4742733

UPDATE

An easier way that worked for me is just include a function at the bottom of the code returning whatever JSON.

// within test code
let movies = getMovieSearchJSON();
.....
...
...
....
// way down below in the code
function getMovieSearchJSON() {
      return {
         "Title": "Bri Squared",
         "Year": "2011",
         "Rated": "N/A",
         "Released": "N/A",
         "Runtime": "N/A",
         "Genre": "Comedy",
         "Director": "Joy Gohring",
         "Writer": "Briana Lane",
         "Actors": "Brianne Davis, Briana Lane, Jorge Garcia, Gabriel Tigerman",
         "Plot": "N/A",
         "Language": "English",
         "Country": "USA",
         "Awards": "N/A",
         "Poster": "http://ia.media-imdb.com/images/M/MV5BMjEzNDUxMDI4OV5BMl5BanBnXkFtZTcwMjE2MzczNQ@@._V1_SX300.jpg",
         "Metascore": "N/A",
         "imdbRating": "8.2",
         "imdbVotes": "5",
         "imdbID": "tt1937109",
         "Type": "movie",
         "Response": "True"
   }
}

What is the command to truncate a SQL Server log file?

if I remember well... in query analyzer or equivalent:

BACKUP LOG  databasename  WITH TRUNCATE_ONLY

DBCC SHRINKFILE (  databasename_Log, 1)

how to query LIST using linq

I would also suggest LinqPad as a convenient way to tackle with Linq for both advanced and beginners.

Example:
enter image description here

how to draw directed graphs using networkx in python?

import networkx as nx
import matplotlib.pyplot as plt

g = nx.DiGraph()
g.add_nodes_from([1,2,3,4,5])
g.add_edge(1,2)
g.add_edge(4,2)
g.add_edge(3,5)
g.add_edge(2,3)
g.add_edge(5,4)

nx.draw(g,with_labels=True)
plt.draw()
plt.show()

This is just simple how to draw directed graph using python 3.x using networkx. just simple representation and can be modified and colored etc. See the generated graph here.

Note: It's just a simple representation. Weighted Edges could be added like

g.add_edges_from([(1,2),(2,5)], weight=2)

and hence plotted again.

Error loading the SDK when Eclipse starts

To remove error from eclipse for android there are few steps:-

1.open eclipse check all the error

2.In search tab open SDK manager

3.Remove all the value show as error in eclipse

4.After remove from sdk restart eclipse

Xcode 4 - "Archive" is greyed out?

You have to select the device in the schemes menu in the top left where you used to select between simulator/device. It won’t let you archive a build for the simulator.

Or you may find that if the iOS device is already selected the archive box isn’t selected when you choose “Edit Schemes” => “Build”.

What are best practices for REST nested resources?

Rails provides a solution to this: shallow nesting.

I think this is a good because when you deal directly with a known resource, there's no need to use nested routes, as has been discussed in other answers here.

Producer/Consumer threads using a Queue

You are reinventing the wheel.

If you need persistence and other enterprise features use JMS (I'd suggest ActiveMq).

If you need fast in-memory queues use one of the impementations of java's Queue.

If you need to support java 1.4 or earlier, use Doug Lea's excellent concurrent package.

What does the ELIFECYCLE Node.js error mean?

I had the same error after I installed new packages or updated them:

...
npm ERR! code ELIFECYCLE
npm ERR! errno 1
...

It helped me to run installation command once again or a couple of times. After that, the error disappeared.

Pushing from local repository to GitHub hosted remote

Type

git push

from the command line inside the repository directory

How to POST using HTTPclient content type = application/x-www-form-urlencoded

The best solution for me is:

// Add key/value
var dict = new Dictionary<string, string>();
dict.Add("Content-Type", "application/x-www-form-urlencoded");

// Execute post method
using (var response = httpClient.PostAsync(path, new FormUrlEncodedContent(dict))){}

pod has unbound PersistentVolumeClaims

You have to define a PersistentVolume providing disc space to be consumed by the PersistentVolumeClaim.

When using storageClass Kubernetes is going to enable "Dynamic Volume Provisioning" which is not working with the local file system.


To solve your issue:

  • Provide a PersistentVolume fulfilling the constraints of the claim (a size >= 100Mi)
  • Remove the storageClass-line from the PersistentVolumeClaim
  • Remove the StorageClass from your cluster

How do these pieces play together?

At creation of the deployment state-description it is usually known which kind (amount, speed, ...) of storage that application will need.
To make a deployment versatile you'd like to avoid a hard dependency on storage. Kubernetes' volume-abstraction allows you to provide and consume storage in a standardized way.

The PersistentVolumeClaim is used to provide a storage-constraint alongside the deployment of an application.

The PersistentVolume offers cluster-wide volume-instances ready to be consumed ("bound"). One PersistentVolume will be bound to one claim. But since multiple instances of that claim may be run on multiple nodes, that volume may be accessed by multiple nodes.

A PersistentVolume without StorageClass is considered to be static.

"Dynamic Volume Provisioning" alongside with a StorageClass allows the cluster to provision PersistentVolumes on demand. In order to make that work, the given storage provider must support provisioning - this allows the cluster to request the provisioning of a "new" PersistentVolume when an unsatisfied PersistentVolumeClaim pops up.


Example PersistentVolume

In order to find how to specify things you're best advised to take a look at the API for your Kubernetes version, so the following example is build from the API-Reference of K8S 1.17:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: ckan-pv-home
  labels:
    type: local
spec:
  capacity:
    storage: 100Mi
  hostPath:
    path: "/mnt/data/ckan"

The PersistentVolumeSpec allows us to define multiple attributes. I chose a hostPath volume which maps a local directory as content for the volume. The capacity allows the resource scheduler to recognize this volume as applicable in terms of resource needs.


Additional Resources:

Add onclick event to newly added element in JavaScript

.onclick should be set to a function instead of a string. Try

elemm.onclick = function() { alert('blah'); };

instead.

angular.service vs angular.factory

Here are the primary differences:

Services

Syntax: module.service( 'serviceName', function );

Result: When declaring serviceName as an injectable argument you will be provided with the instance of a function passed to module.service.

Usage: Could be useful for sharing utility functions that are useful to invoke by simply appending ( ) to the injected function reference. Could also be run with injectedArg.call( this ) or similar.

Factories

Syntax: module.factory( 'factoryName', function );

Result: When declaring factoryName as an injectable argument you will be provided with the value that is returned by invoking the function reference passed to module.factory.

Usage: Could be useful for returning a 'class' function that can then be new'ed to create instances.

Here is example using services and factory. Read more about AngularJS Service vs Factory.

You can also check the AngularJS documentation and similar question on stackoverflow confused about service vs factory.

How can I convert a string to an int in Python?

>>> a = "123"
>>> int(a)
123

Here's some freebie code:

def getTwoNumbers():
    numberA = raw_input("Enter your first number: ")
    numberB = raw_input("Enter your second number: ")
    return int(numberA), int(numberB)

How to increment a pointer address and pointer's value?

The following is an instantiation of the various "just print it" suggestions. I found it instructive.

#include "stdio.h"

int main() {
    static int x = 5;
    static int *p = &x;
    printf("(int) p   => %d\n",(int) p);
    printf("(int) p++ => %d\n",(int) p++);
    x = 5; p = &x;
    printf("(int) ++p => %d\n",(int) ++p);
    x = 5; p = &x;
    printf("++*p      => %d\n",++*p);
    x = 5; p = &x;
    printf("++(*p)    => %d\n",++(*p));
    x = 5; p = &x;
    printf("++*(p)    => %d\n",++*(p));
    x = 5; p = &x;
    printf("*p++      => %d\n",*p++);
    x = 5; p = &x;
    printf("(*p)++    => %d\n",(*p)++);
    x = 5; p = &x;
    printf("*(p)++    => %d\n",*(p)++);
    x = 5; p = &x;
    printf("*++p      => %d\n",*++p);
    x = 5; p = &x;
    printf("*(++p)    => %d\n",*(++p));
    return 0;
}

It returns

(int) p   => 256688152
(int) p++ => 256688152
(int) ++p => 256688156
++*p      => 6
++(*p)    => 6
++*(p)    => 6
*p++      => 5
(*p)++    => 5
*(p)++    => 5
*++p      => 0
*(++p)    => 0

I cast the pointer addresses to ints so they could be easily compared.

I compiled it with GCC.

How to do tag wrapping in VS code?

imo there's a better answer for this using Snippets

Create a snippet with a definition like this:

"name_of_your_snippet": {
    "scope": "javascript,html",
    "prefix": "name_of_your_snippet",
    "body": "<${0:b}>$TM_SELECTED_TEXT</${0:b}>"
}

Then bind it to a key in keybindings.json E.g. like this:

{ 
    "key": "alt+w",
    "command": "editor.action.insertSnippet",
    "args": { "name": "name_of_your_snippet" }
}

I think this should give you exactly the same result as htmltagwrap but without having to install an extension.

It will insert tags around selected text, defaults to <b> tag & selects the tag so typing lets you change it.

If you want to use a different default tag just change the b in the body property of the snippet.

Oracle 12c Installation failed to access the temporary location

You can configure setup.exe to skip this check using the parameters below -

setup.exe -ignorePrereq -ignorePrereq -J"-Doracle.install.db.validate.supportedOSCheck=false"

Get root password for Google Cloud Engine VM

Figured it out. The VM's in cloud engine don't come with a root password setup by default so you'll first need to change the password using

sudo passwd

If you do everything correctly, it should do something like this:

user@server[~]# sudo passwd
Changing password for user root.
New password: 
Retype new password: 
passwd: all authentication tokens updated successfully.

How to override the [] operator in Python?

To fully overload it you also need to implement the __setitem__and __delitem__ methods.

edit

I almost forgot... if you want to completely emulate a list, you also need __getslice__, __setslice__ and __delslice__.

There are all documented in http://docs.python.org/reference/datamodel.html

NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference

Change

 mAdapter = new RecordingsListAdapter(this, recordings);

to

 mAdapter = new RecordingsListAdapter(getActivity(), recordings);

and also make sure that recordings!=null at mAdapter = new RecordingsListAdapter(this, recordings);

What is Parse/parsing?

Parsing is to read the value of one object to convert it to another type. For example you may have a string with a value of "10". Internally that string contains the Unicode characters '1' and '0' not the actual number 10. The method Integer.parseInt takes that string value and returns a real number.

String tenString = "10"

//This won't work since you can't add an integer and a string
Integer result = 20 + tenString;

//This will set result to 30
Integer result = 20 + Integer.parseInt(tenString);

"No such file or directory" error when executing a binary

It is possible that the executable is statically linked and that is why ldd gzip does not see any links - because it isn't. I don't know much about things that far back so I don't know if there would be incompatibilities if libraries are linked in statically. I might expect there to be.

I know it's the most obvious thing going and I'm sure you've done it, but chmod +x ./gzip, yes? No such file or directory is a classic symptom of that not being done, that's why I mention it.

Python IndentationError: unexpected indent

Check if you mixed tabs and spaces, that is a frequent source of indentation errors.

How to rename a single column in a data.frame?

This is a generalized way in which you do not have to remember the exact location of the variable:

# df = dataframe
# old.var.name = The name you don't like anymore
# new.var.name = The name you want to get

names(df)[names(df) == 'old.var.name'] <- 'new.var.name'

This code pretty much does the following:

  1. names(df) looks into all the names in the df
  2. [names(df) == old.var.name] extracts the variable name you want to check
  3. <- 'new.var.name' assigns the new variable name.

use current date as default value for a column

Add a default constraint with the GETDATE() function as value.

ALTER TABLE myTable 
  ADD CONSTRAINT CONSTRAINT_NAME
    DEFAULT GETDATE() FOR myColumn

Comparing two dataframes and getting the differences

# given
df1=pd.DataFrame({'Date':['2013-11-24','2013-11-24','2013-11-24','2013-11-24'],
    'Fruit':['Banana','Orange','Apple','Celery'],
    'Num':[22.1,8.6,7.6,10.2],
    'Color':['Yellow','Orange','Green','Green']})
df2=pd.DataFrame({'Date':['2013-11-24','2013-11-24','2013-11-24','2013-11-24','2013-11-25','2013-11-25'],
    'Fruit':['Banana','Orange','Apple','Celery','Apple','Orange'],
    'Num':[22.1,8.6,7.6,1000,22.1,8.6],
    'Color':['Yellow','Orange','Green','Green','Red','Orange']})

# find which rows are in df2 that aren't in df1 by Date and Fruit
df_2notin1 = df2[~(df2['Date'].isin(df1['Date']) & df2['Fruit'].isin(df1['Fruit']) )].dropna().reset_index(drop=True)

# output
print('df_2notin1\n', df_2notin1)
#      Color        Date   Fruit   Num
# 0     Red  2013-11-25   Apple  22.1
# 1  Orange  2013-11-25  Orange   8.6

Convert a tensor to numpy array in Tensorflow?

If you see there is a method _numpy(), e.g for an EagerTensor simply call the above method and you will get an ndarray.

How to render pdfs using C#

Use the web browser control. This requires Adobe reader to be installed but most likely you have it anyway. Set the UrL of the control to the file location.

In-place type conversion of a NumPy array

Use this:

In [105]: a
Out[105]: 
array([[15, 30, 88, 31, 33],
       [53, 38, 54, 47, 56],
       [67,  2, 74, 10, 16],
       [86, 33, 15, 51, 32],
       [32, 47, 76, 15, 81]], dtype=int32)

In [106]: float32(a)
Out[106]: 
array([[ 15.,  30.,  88.,  31.,  33.],
       [ 53.,  38.,  54.,  47.,  56.],
       [ 67.,   2.,  74.,  10.,  16.],
       [ 86.,  33.,  15.,  51.,  32.],
       [ 32.,  47.,  76.,  15.,  81.]], dtype=float32)

Set a Fixed div to 100% width of the parent container

Remove Padding: 10%; or use px instead of percent for .wrap

see the example : http://jsfiddle.net/C93mk/493/

HTML :

<div id="wrapper">
    <div id="wrap">
    Some relative item placed item
    <div id="fixed"></div>
    </div>
</div>

CSS:

body{ height:20000px }
#wrapper {padding:10%;}
#wrap{ 
    float: left;
    position: relative;
    width: 200px; 
    background:#ccc; 
}
#fixed{ 
    position:fixed;
    width:inherit;
    padding:0px;
    height:10px;
    background-color:#333;

}

How to determine the first and last iteration in a foreach loop?

foreach ($arquivos as $key => $item) {
   reset($arquivos);
   // FIRST AHEAD
   if ($key === key($arquivos) || $key !== end(array_keys($arquivos)))
       $pdf->cat(null, null, $key);

   // LAST
   if ($key === end(array_keys($arquivos))) {
       $pdf->cat(null, null, $key)
           ->execute();
   }
}

Get clicked item and its position in RecyclerView

Everytime I use another approach. People seem to store or get position on a view, rather than storing a reference to an object that is displayed by ViewHolder.

I use this approach instead, and just store it in ViewHolder when onBindViewHolder() is called, and set reference to null in onViewRecycled().

Every time ViewHolder becomes invisible, it's recycled. So this doesn't affect in large memory consumption.

@Override
public void onBindViewHolder(final ItemViewHolder holder, int position) {
    ...
    holder.displayedItem = adapterItemsList.get(i);
    ...
}

@Override
public void onViewRecycled(ItemViewHolder holder) {
    ...
    holder.displayedItem = null;
    ...
}

class ItemViewHolder extends RecyclerView.ViewHolder {
    ...
    MySuperItemObject displayedItem = null;
    ...
}

MongoDB vs Firebase

Apples and oranges. Firebase is a Backend-as-a-Service containing identity management, realtime data views and a document database. It runs in the cloud.

MongoDB on the other hand is a full fledged database with a rich query language. In principle it runs on your own machine, but there are cloud providers.

If you are looking for the database component only MongoDB is much more mature and feature-rich.

In PHP, how can I add an object element to an array?

Here is a clean method I've discovered:

$myArray = [];

array_push($myArray, (object)[
        'key1' => 'someValue',
        'key2' => 'someValue2',
        'key3' => 'someValue3',
]);

return $myArray;

What's the best way to select the minimum value from several columns?

Using CROSS APPLY:

SELECT ID, Col1, Col2, Col3, MinValue
FROM YourTable
CROSS APPLY (SELECT MIN(d) AS MinValue FROM (VALUES (Col1), (Col2), (Col3)) AS a(d)) A

SQL Fiddle

Concatenating elements in an array to a string

For those who develop in Android, use TextUtils.

String items = TextUtils.join("", arr);

Assuming arr is of type String[] arr= {"1","2","3"};

The output would be 123

Why does the preflight OPTIONS request of an authenticated CORS request work in Chrome but not Firefox?

This is an old post but maybe this could help people to complete the CORS problem. To complete the basic authorization problem you should avoid authorization for OPTIONS requests in your server. This is an Apache configuration example. Just add something like this in your VirtualHost or Location.

<LimitExcept OPTIONS>
    AuthType Basic
    AuthName <AUTH_NAME>
    Require valid-user
    AuthUserFile <FILE_PATH>
</LimitExcept>

How do I specify unique constraint for multiple columns in MySQL?

Have you tried this ?

UNIQUE KEY `thekey` (`user`,`email`,`address`)

Ruby: What is the easiest way to remove the first element from an array?

"pop"ing the first element of an Array is called "shift" ("unshift" being the operation of adding one element in front of the array).

What is the difference between 0.0.0.0, 127.0.0.1 and localhost?

127.0.0.1 is normally the IP address assigned to the "loopback" or local-only interface. This is a "fake" network adapter that can only communicate within the same host. It's often used when you want a network-capable application to only serve clients on the same host. A process that is listening on 127.0.0.1 for connections will only receive local connections on that socket.

"localhost" is normally the hostname for the 127.0.0.1 IP address. It's usually set in /etc/hosts (or the Windows equivalent named "hosts" somewhere under %WINDIR%). You can use it just like any other hostname - try "ping localhost" to see how it resolves to 127.0.0.1.

0.0.0.0 has a couple of different meanings, but in this context, when a server is told to listen on 0.0.0.0 that means "listen on every available network interface". The loopback adapter with IP address 127.0.0.1 from the perspective of the server process looks just like any other network adapter on the machine, so a server told to listen on 0.0.0.0 will accept connections on that interface too.

That hopefully answers the IP side of your question. I'm not familiar with Jekyll or Vagrant, but I'm guessing that your port forwarding 8080 => 4000 is somehow bound to a particular network adapter, so it isn't in the path when you connect locally to 127.0.0.1

How do I calculate power-of in C#?

Following is the code calculating power of decimal value for RaiseToPower for both -ve and +ve values.

public decimal Power(decimal number, decimal raiseToPower)
        {
            decimal result = 0;
            if (raiseToPower < 0)
            {
                raiseToPower *= -1;
                result = 1 / number;
                for (int i = 1; i < raiseToPower; i++)
                {
                    result /= number;
                }
            }
            else
            {
                result = number;
                for (int i = 0; i <= raiseToPower; i++)
                {
                    result *= number;
                }
            }
            return result;
        }

Partial Dependency (Databases)

Partial dependency implies is a situation where a non-prime attribute(An attribute that does not form part of the determinant(Primary key/Candidate key)) is functionally dependent to a portion/part of a primary key/Candidate key.

How can I export Excel files using JavaScript?

To answer your question with a working example:

<script type="text/javascript">
function DownloadJSON2CSV(objArray)
{
    var array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;

    var str = '';

    for (var i = 0; i < array.length; i++) {
        var line = new Array();

        for (var index in array[i]) {
           line.push('"' + array[i][index] + '"');
        }

        str += line.join(';');
        str += '\r\n';
    }
    window.open( "data:text/csv;charset=utf-8," + encodeURIComponent(str));
}
</script>

What is the difference between Eclipse for Java (EE) Developers and Eclipse Classic?

If you want to build Java EE applications, it's best to use Eclipse IDE for Java EE. It has editors from HTML to JSP/JSF, Javascript. It's rich for webapps development, and provide plugins and tools to develop Java EE applications easily (all bundled).

Eclipse Classic is basically the full featured Eclipse without the Java EE part.

How do I get the current mouse screen coordinates in WPF?

Mouse.GetPosition(mWindow) gives you the mouse position relative to the parameter of your choice. mWindow.PointToScreen() convert the position to a point relative to the screen.

So mWindow.PointToScreen(Mouse.GetPosition(mWindow)) gives you the mouse position relative to the screen, assuming that mWindow is a window(actually, any class derived from System.Windows.Media.Visual will have this function), if you are using this inside a WPF window class, this should work.

Get a list of dates between two dates using a function

Would all these dates be in the database already or do you just want to know the days between the two dates? If it's the first you could use the BETWEEN or <= >= to find the dates between

EXAMPLE:

SELECT column_name(s)
FROM table_name
WHERE column_name
BETWEEN value1 AND value2

OR

SELECT column_name(s)
FROM table_name
WHERE column_name
value1 >= column_name
AND column_name =< value2

How can I get the average (mean) of selected columns

Here are some examples:

> z$mean <- rowMeans(subset(z, select = c(x, y)), na.rm = TRUE)
> z
  w x  y mean
1 5 1  1    1
2 6 2  2    2
3 7 3  3    3
4 8 4 NA    4

weighted mean

> z$y <- rev(z$y)
> z
  w x  y mean
1 5 1 NA    1
2 6 2  3    2
3 7 3  2    3
4 8 4  1    4
> 
> weight <- c(1, 2) # x * 1/3 + y * 2/3
> z$wmean <- apply(subset(z, select = c(x, y)), 1, function(d) weighted.mean(d, weight, na.rm = TRUE))
> z
  w x  y mean    wmean
1 5 1 NA    1 1.000000
2 6 2  3    2 2.666667
3 7 3  2    3 2.333333
4 8 4  1    4 2.000000

Spring 5.0.3 RequestRejectedException: The request was rejected because the URL was not normalized

setAllowUrlEncodedSlash(true) didn't work for me. Still internal method isNormalized return false when having double slash.

I replaced StrictHttpFirewall with DefaultHttpFirewall by having the following code only:

@Bean
public HttpFirewall defaultHttpFirewall() {
    return new DefaultHttpFirewall();
}

Working well for me.
Any risk by using DefaultHttpFirewall?

Right pad a string with variable number of spaces

Whammo blammo (for leading spaces):

SELECT 
    RIGHT(space(60) + cust_name, 60),
    RIGHT(space(60) + cust_address, 60)

OR (for trailing spaces)

SELECT
    LEFT(cust_name + space(60), 60),
    LEFT(cust_address + space(60), 60),

List files ONLY in the current directory

You can use the pathlib module.

from pathlib import Path
x = Path('./')
print(list(filter(lambda y:y.is_file(), x.iterdir())))

INNER JOIN vs LEFT JOIN performance in SQL Server

A LEFT JOIN is absolutely not faster than an INNER JOIN. In fact, it's slower; by definition, an outer join (LEFT JOIN or RIGHT JOIN) has to do all the work of an INNER JOIN plus the extra work of null-extending the results. It would also be expected to return more rows, further increasing the total execution time simply due to the larger size of the result set.

(And even if a LEFT JOIN were faster in specific situations due to some difficult-to-imagine confluence of factors, it is not functionally equivalent to an INNER JOIN, so you cannot simply go replacing all instances of one with the other!)

Most likely your performance problems lie elsewhere, such as not having a candidate key or foreign key indexed properly. 9 tables is quite a lot to be joining so the slowdown could literally be almost anywhere. If you post your schema, we might be able to provide more details.


Edit:

Reflecting further on this, I could think of one circumstance under which a LEFT JOIN might be faster than an INNER JOIN, and that is when:

  • Some of the tables are very small (say, under 10 rows);
  • The tables do not have sufficient indexes to cover the query.

Consider this example:

CREATE TABLE #Test1
(
    ID int NOT NULL PRIMARY KEY,
    Name varchar(50) NOT NULL
)
INSERT #Test1 (ID, Name) VALUES (1, 'One')
INSERT #Test1 (ID, Name) VALUES (2, 'Two')
INSERT #Test1 (ID, Name) VALUES (3, 'Three')
INSERT #Test1 (ID, Name) VALUES (4, 'Four')
INSERT #Test1 (ID, Name) VALUES (5, 'Five')

CREATE TABLE #Test2
(
    ID int NOT NULL PRIMARY KEY,
    Name varchar(50) NOT NULL
)
INSERT #Test2 (ID, Name) VALUES (1, 'One')
INSERT #Test2 (ID, Name) VALUES (2, 'Two')
INSERT #Test2 (ID, Name) VALUES (3, 'Three')
INSERT #Test2 (ID, Name) VALUES (4, 'Four')
INSERT #Test2 (ID, Name) VALUES (5, 'Five')

SELECT *
FROM #Test1 t1
INNER JOIN #Test2 t2
ON t2.Name = t1.Name

SELECT *
FROM #Test1 t1
LEFT JOIN #Test2 t2
ON t2.Name = t1.Name

DROP TABLE #Test1
DROP TABLE #Test2

If you run this and view the execution plan, you'll see that the INNER JOIN query does indeed cost more than the LEFT JOIN, because it satisfies the two criteria above. It's because SQL Server wants to do a hash match for the INNER JOIN, but does nested loops for the LEFT JOIN; the former is normally much faster, but since the number of rows is so tiny and there's no index to use, the hashing operation turns out to be the most expensive part of the query.

You can see the same effect by writing a program in your favourite programming language to perform a large number of lookups on a list with 5 elements, vs. a hash table with 5 elements. Because of the size, the hash table version is actually slower. But increase it to 50 elements, or 5000 elements, and the list version slows to a crawl, because it's O(N) vs. O(1) for the hashtable.

But change this query to be on the ID column instead of Name and you'll see a very different story. In that case, it does nested loops for both queries, but the INNER JOIN version is able to replace one of the clustered index scans with a seek - meaning that this will literally be an order of magnitude faster with a large number of rows.

So the conclusion is more or less what I mentioned several paragraphs above; this is almost certainly an indexing or index coverage problem, possibly combined with one or more very small tables. Those are the only circumstances under which SQL Server might sometimes choose a worse execution plan for an INNER JOIN than a LEFT JOIN.

Generate a unique id

This question seems to be answered, however for completeness, I would add another approach.

You can use a unique ID number generator which is based on Twitter's Snowflake id generator. C# implementation can be found here.

var id64Generator = new Id64Generator();

// ...

public string generateID(string sourceUrl)
{
    return string.Format("{0}_{1}", sourceUrl, id64Generator.GenerateId());
}

Note that one of very nice features of that approach is possibility to have multiple generators on independent nodes (probably something useful for a search engine) generating real time, globally unique identifiers.

// node 0
var id64Generator = new Id64Generator(0);

// node 1
var id64Generator = new Id64Generator(1);

// ... node 10
var id64Generator = new Id64Generator(10);

Truncate with condition

As a response to your question: "i want to reset all the data and keep last 30 days inside the table."

you can create an event. Check https://dev.mysql.com/doc/refman/5.7/en/event-scheduler.html

For example:

CREATE EVENT DeleteExpiredLog
ON SCHEDULE EVERY 1 DAY
DO
DELETE FROM log WHERE date < DATE_SUB(NOW(), INTERVAL 30 DAY);

Will run a daily cleanup in your table, keeping the last 30 days data available

Why binary_crossentropy and categorical_crossentropy give different performances for the same problem?

The reason for this apparent performance discrepancy between categorical & binary cross entropy is what user xtof54 has already reported in his answer below, i.e.:

the accuracy computed with the Keras method evaluate is just plain wrong when using binary_crossentropy with more than 2 labels

I would like to elaborate more on this, demonstrate the actual underlying issue, explain it, and offer a remedy.

This behavior is not a bug; the underlying reason is a rather subtle & undocumented issue at how Keras actually guesses which accuracy to use, depending on the loss function you have selected, when you include simply metrics=['accuracy'] in your model compilation. In other words, while your first compilation option

model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])

is valid, your second one:

model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])

will not produce what you expect, but the reason is not the use of binary cross entropy (which, at least in principle, is an absolutely valid loss function).

Why is that? If you check the metrics source code, Keras does not define a single accuracy metric, but several different ones, among them binary_accuracy and categorical_accuracy. What happens under the hood is that, since you have selected binary cross entropy as your loss function and have not specified a particular accuracy metric, Keras (wrongly...) infers that you are interested in the binary_accuracy, and this is what it returns - while in fact you are interested in the categorical_accuracy.

Let's verify that this is the case, using the MNIST CNN example in Keras, with the following modification:

model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])  # WRONG way

model.fit(x_train, y_train,
          batch_size=batch_size,
          epochs=2,  # only 2 epochs, for demonstration purposes
          verbose=1,
          validation_data=(x_test, y_test))

# Keras reported accuracy:
score = model.evaluate(x_test, y_test, verbose=0) 
score[1]
# 0.9975801164627075

# Actual accuracy calculated manually:
import numpy as np
y_pred = model.predict(x_test)
acc = sum([np.argmax(y_test[i])==np.argmax(y_pred[i]) for i in range(10000)])/10000
acc
# 0.98780000000000001

score[1]==acc
# False    

To remedy this, i.e. to use indeed binary cross entropy as your loss function (as I said, nothing wrong with this, at least in principle) while still getting the categorical accuracy required by the problem at hand, you should ask explicitly for categorical_accuracy in the model compilation as follows:

from keras.metrics import categorical_accuracy
model.compile(loss='binary_crossentropy', optimizer='adam', metrics=[categorical_accuracy])

In the MNIST example, after training, scoring, and predicting the test set as I show above, the two metrics now are the same, as they should be:

# Keras reported accuracy:
score = model.evaluate(x_test, y_test, verbose=0) 
score[1]
# 0.98580000000000001

# Actual accuracy calculated manually:
y_pred = model.predict(x_test)
acc = sum([np.argmax(y_test[i])==np.argmax(y_pred[i]) for i in range(10000)])/10000
acc
# 0.98580000000000001

score[1]==acc
# True    

System setup:

Python version 3.5.3
Tensorflow version 1.2.1
Keras version 2.0.4

UPDATE: After my post, I discovered that this issue had already been identified in this answer.

Change a branch name in a Git repo

If you're currently on the branch you want to rename:

git branch -m new_name 

Or else:

git branch -m old_name new_name 

You can check with:

git branch -a

As you can see, only the local name changed Now, to change the name also in the remote you must do:

git push origin :old_name

This removes the branch, then upload it with the new name:

git push origin new_name

Source: https://web.archive.org/web/20150929104013/http://blog.changecong.com:80/2012/10/rename-a-remote-branch-on-github

How to make a form close when pressing the escape key?

The best way i found is to override the "ProcessDialogKey" function. This way canceling a open control is still possible because the function is only called when no other control uses the pressed Key.

This is the same behaviour as when setting a CancelButton. Using the KeyDown Event fires always and thus the form would close even when it should cancel the edit of an open editor.

protected override bool ProcessDialogKey(Keys keyData)
{
    if (Form.ModifierKeys == Keys.None && keyData == Keys.Escape)
    {
        this.Close();
        return true;
    }
    return base.ProcessDialogKey(keyData);
}

How to save a plot into a PDF file without a large margin around

It seems to me that all approaches (file exchange solutions unconsidered) here are lacking the essential step, or finally leading to it via some blurry workarounds.

The figure size needs to equal the paper size and the white margins are gone.

A = hgload('myFigure.fig');

% set desired output size
set(A, 'Units','centimeters')
height = 15;
width = 19;

% the last two parameters of 'Position' define the figure size
set(A, 'Position',[25 5 width height],...
       'PaperSize',[width height],...
       'PaperPositionMode','auto',...
       'InvertHardcopy', 'off',...
       'Renderer','painters'...     %recommended if there are no alphamaps
   );

saveas(A,'printout','pdf')

Will give you a pdf output as your figure appears, in exactly the size you want. If you want to get it even tighter you can combine this solution with the answer of b3.

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

Have a look at https://wiki.debian.org/JavaPackage At the bottom of this page an other method is descibed using a command from the java-common package

get original element from ng-click

Not a direct answer to this question but rather to the "issue" of $event.currentTarget apparently be set to null.

This is due to the fact that console.log shows deep mutable objects at the last state of execution, not at the state when console.log was called.

You can check this for more information: Consecutive calls to console.log produce inconsistent results

KnockoutJs v2.3.0 : Error You cannot apply bindings multiple times to the same element

You just have to remove the bindings before you use 'applyBindings' again.

ko.cleanNode($element[0]);

should do the trick. HTH.

How do I add a simple onClick event handler to a canvas element?

When you draw to a canvas element, you are simply drawing a bitmap in immediate mode.

The elements (shapes, lines, images) that are drawn have no representation besides the pixels they use and their colour.

Therefore, to get a click event on a canvas element (shape), you need to capture click events on the canvas HTML element and use some math to determine which element was clicked, provided you are storing the elements' width/height and x/y offset.

To add a click event to your canvas element, use...

canvas.addEventListener('click', function() { }, false);

To determine which element was clicked...

var elem = document.getElementById('myCanvas'),
    elemLeft = elem.offsetLeft + elem.clientLeft,
    elemTop = elem.offsetTop + elem.clientTop,
    context = elem.getContext('2d'),
    elements = [];

// Add event listener for `click` events.
elem.addEventListener('click', function(event) {
    var x = event.pageX - elemLeft,
        y = event.pageY - elemTop;

    // Collision detection between clicked offset and element.
    elements.forEach(function(element) {
        if (y > element.top && y < element.top + element.height 
            && x > element.left && x < element.left + element.width) {
            alert('clicked an element');
        }
    });

}, false);

// Add element.
elements.push({
    colour: '#05EFFF',
    width: 150,
    height: 100,
    top: 20,
    left: 15
});

// Render elements.
elements.forEach(function(element) {
    context.fillStyle = element.colour;
    context.fillRect(element.left, element.top, element.width, element.height);
});?

jsFiddle.

This code attaches a click event to the canvas element, and then pushes one shape (called an element in my code) to an elements array. You could add as many as you wish here.

The purpose of creating an array of objects is so we can query their properties later. After all the elements have been pushed onto the array, we loop through and render each one based on their properties.

When the click event is triggered, the code loops through the elements and determines if the click was over any of the elements in the elements array. If so, it fires an alert(), which could easily be modified to do something such as remove the array item, in which case you'd need a separate render function to update the canvas.


For completeness, why your attempts didn't work...

elem.onClick = alert("hello world"); // displays alert without clicking

This is assigning the return value of alert() to the onClick property of elem. It is immediately invoking the alert().

elem.onClick = alert('hello world');  // displays alert without clicking

In JavaScript, the ' and " are semantically identical, the lexer probably uses ['"] for quotes.

elem.onClick = "alert('hello world!')"; // does nothing, even with clicking

You are assigning a string to the onClick property of elem.

elem.onClick = function() { alert('hello world!'); }; // does nothing

JavaScript is case sensitive. The onclick property is the archaic method of attaching event handlers. It only allows one event to be attached with the property and the event can be lost when serialising the HTML.

elem.onClick = function() { alert("hello world!"); }; // does nothing

Again, ' === ".

HTML.ActionLink vs Url.Action in ASP.NET Razor

I used the code below to create a Button and it worked for me.

<input type="button" value="PDF" onclick="location.href='@Url.Action("Export","tblOrder")'"/>

How to get the URL without any parameters in JavaScript?

This is possible, but you'll have to build it manually from the location object:

location.protocol + '//' + location.host + location.pathname

Checking to see if one array's elements are in another array in PHP

That code is invalid as you can only pass variables into language constructs. empty() is a language construct.

You have to do this in two lines:

$result = array_intersect($people, $criminals);
$result = !empty($result);

Location of GlassFish Server Logs

tail -f /path/to/glassfish/domains/YOURDOMAIN/logs/server.log

You can also upload log from admin console : http://yoururl:4848

enter image description here

Connection Java-MySql : Public Key Retrieval is not allowed

Give connection URL as jdbc:mysql://localhost:3306/hb_student_tracker?allowPublicKeyRetrieval=true&useSSL=false&serverTimezone=UTC

How to select the last record of a table in SQL?

You can also do something like this:

SELECT LAST (column_name) AS LAST_CUSTOMER FROM table_name;

Android Studio not showing modules in project structure

Go to File->Project Structure-> Project Settings -> Modules.

Click on the green colored + and add new module. select Application module and set the content root to your project module.

Click next and then finish.

Reference

Cross browser JavaScript (not jQuery...) scroll to top animation

Use this solution

animate(document.documentElement, 'scrollTop', 0, 200);

Thanks

How do I loop through items in a list box and then remove those item?

Jefferson is right, you have to do it backwards.

Here's the c# equivalent:

for (var i == list.Items.Count - 1; i >= 0; i--)
{
    list.Items.RemoveAt(i);
}

How to change screen resolution of Raspberry Pi

After uncommenting disable_overscan=1 follow my lead. In the link, http://elinux.org/RPiconfig when you search for Video options, you'll also get hdmi_group and hdmi_mode. For, hdmi_group choose 1 if you're using you TV as an video output or choose 2 for monitors. Then in hdmi_mode, you can select the resolution you want from the list. I chose :- hdmi_group=2 hdmi_mode=23 And it worked.enter image description here

To get specific part of a string in c#

Your question is vague (are you always looking for the first part?), but you can get the exact output you asked for with string.Split:

string[] substrings = a.Split(',');
b = substrings[0];
Console.WriteLine(b);

Output:

abc

How to set character limit on the_content() and the_excerpt() in wordpress

just to help, if any one want to limit post length at home page .. then can use below code to do that..

the below code is simply a modification of @bfred.it Sir

add_filter("the_content", "break_text");

function limit_text($text){

  if(is_front_page())
  {
    $length = 250;
    if(strlen($text)<$length+10) return $text; //don't cut if too short
    $break_pos = strpos($text, ' ', $length); //find next space after desired length
    $visible = substr($text, 0, $break_pos);
    return balanceTags($visible) . "... <a href='".get_permalink()."'>read more</a>";
  }else{
    return $text;
  }

}

How to export SQL Server 2005 query to CSV

Yeah, there is a very simple utility in Management Studio, if you're just looking to save query results to a CSV.

Right click on the result set, the select "Save Results As". The default file type is CSV.

Using a Loop to add objects to a list(python)

The problem appears to be that you are reinitializing the list to an empty list in each iteration:

while choice != 0:
    ...
    a = []
    a.append(s)

Try moving the initialization above the loop so that it is executed only once.

a = []
while choice != 0:
    ...
    a.append(s)

HTML: Changing colors of specific words in a string of text

You can also make a class:

<span class="mychangecolor"> I am in yellow color!!!!!!</span>

then in a css file do:

.mychangecolor{ color:#ff5 /* it changes to yellow */ }

Iterate over elements of List and Map using JSTL <c:forEach> tag

Mark, this is already answered in your previous topic. But OK, here it is again:

Suppose ${list} points to a List<Object>, then the following

<c:forEach items="${list}" var="item">
    ${item}<br>
</c:forEach>

does basically the same as as following in "normal Java":

for (Object item : list) {
    System.out.println(item);
}

If you have a List<Map<K, V>> instead, then the following

<c:forEach items="${list}" var="map">
    <c:forEach items="${map}" var="entry">
        ${entry.key}<br>
        ${entry.value}<br>
    </c:forEach>
</c:forEach>

does basically the same as as following in "normal Java":

for (Map<K, V> map : list) {
    for (Entry<K, V> entry : map.entrySet()) {
        System.out.println(entry.getKey());
        System.out.println(entry.getValue());
    }
}

The key and value are here not special methods or so. They are actually getter methods of Map.Entry object (click at the blue Map.Entry link to see the API doc). In EL (Expression Language) you can use the . dot operator to access getter methods using "property name" (the getter method name without the get prefix), all just according the Javabean specification.

That said, you really need to cleanup the "answers" in your previous topic as they adds noise to the question. Also read the comments I posted in your "answers".

import sun.misc.BASE64Encoder results in error compiled in Eclipse

I had this problem on jdk1.6.0_37. This is the only JDE/JRE on my system. I don't know why, but the following solved the problem:

Project -> Properties -> Java Build Path - > Libraries

Switch radio button from Execution environment to Alernate JRE. This selects the same jdk1.6.0_37, but after clean/build the compile error disappeared.

Maybe clarification in answer from ram (Mar 16 at 9:00) has to do something with that.

"Cannot start compilation: the output path is not specified for module..."

Two things to do:

  1. Project Settings > Project compiler output > Set it as "Project path(You actual project's path)”+”\out”.

  2. Project Settings > Module > Path > Choose "Inherit project compile path"

Node.js - SyntaxError: Unexpected token import

In my case it was looking after .babelrc file, and it should contain something like this:

{
  "presets": ["es2015-node5", "stage-3"],
  "plugins": []
}

Git add all subdirectories

You can also face problems if a subdirectory itself is a git repository - ie .has a .git directory - check with ls -a.

To remove go to the subdirectory and rm .git -rf.

Passing parameter using onclick or a click binding with KnockoutJS

I know this is an old question, but here is my contribution. Instead of all these tricks, you can just simply wrap a function inside another function. Like I have done here:

<div data-bind="click: function(){ f('hello parameter'); }">Click me once</div>
<div data-bind="click: function(){ f('no no parameter'); }">Click me twice</div>

var VM = function(){
   this.f = function(param){
     console.log(param);
   }
}
ko.applyBindings(new VM());

And here is the fiddle

Java: how do I initialize an array size if it's unknown?

If you want to stick to an array then this way you can make use. But its not good as compared to List and not recommended. However it will solve your problem.

import java.util.Scanner;

public class ArrayModify {

    public static void main(String[] args) {
        int[] list;
        String st;
        String[] stNew;
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter Numbers: "); // If user enters 5 6 7 8 9 
        st = scan.nextLine();
        stNew = st.split("\\s+");
        list = new int[stNew.length]; // Sets array size to 5

        for (int i = 0; i < stNew.length; i++){
            list[i] =  Integer.parseInt(stNew[i]);
            System.out.println("You Enterred: " + list[i]);
        }
    }
}

How do I clear only a few specific objects from the workspace?

A useful way to remove a whole set of named-alike objects:

rm(list = ls()[grep("^tmp", ls())])

thereby removing all objects whose name begins with the string "tmp".

Edit: Following Gsee's comment, making use of the pattern argument:

rm(list = ls(pattern = "^tmp"))

Edit: Answering Rafael comment, one way to retain only a subset of objects is to name the data you want to retain with a specific pattern. For example if you wanted to remove all objects whose name do not start with paper you would issue the following command:

rm(list = grep("^paper", ls(), value = TRUE, invert = TRUE))

SyntaxError: Cannot use import statement outside a module

simple just change it to : const uuidv1 = require('uuid'); it will work fine.

How do I make an Android EditView 'Done' button and hide the keyboard when clicked?

Actually you can set custom text to that little blue button. In the xml file just use

android:imeActionLabel="whatever"

on your EditText.

Or in the java file use

etEditText.setImeActionLabel("whatever", EditorInfo.IME_ACTION_DONE);

I arbitrarily choose IME_ACTION_DONE as an example of what should go in the second parameter for this function. A full list of these actions can be found here.

It should be noted that this will not cause text to appear on all keyboards on all devices. Some keyboards do not support text on that button (e.g. swiftkey). And some devices don't support it either. A good rule is, if you see text already on the button, this will change it to whatever you'd want.

How to view method information in Android Studio?

If you need only Parameter info then:

On Mac, it's assigned to Command+P

On Windows, it's assigned to Ctrl+P

If you need document info then:

On Mac, it's assigned to Command+Q

On Windows, it's assigned to Ctrl+Q

How do I Search/Find and Replace in a standard string?

#include <string>

using std::string;

void myReplace(string& str,
               const string& oldStr,
               const string& newStr) {
  if (oldStr.empty()) {
    return;
  }

  for (size_t pos = 0; (pos = str.find(oldStr, pos)) != string::npos;) {
    str.replace(pos, oldStr.length(), newStr);
    pos += newStr.length();
  }
}

The check for oldStr being empty is important. If for whatever reason that parameter is empty you will get stuck in an infinite loop.

But yeah use the tried and tested C++11 or Boost solution if you can.

Two HTML tables side by side, centered on the page

The problem is that the DIV that should center your tables has no width defined. By default, DIVs are block elements and take up the entire width of their parent - in this case the entire document (propagating through the #outer DIV), so the automatic margin style has no effect.

For this technique to work, you simply have to set the width of the div that has margin:auto to anything but "auto" or "inherit" (either a fixed pixel value or a percentage).

Sass calculate percent minus px

$var:25%;
$foo:5px;
.selector {
    height:unquote("calc( #{$var} - #{$foo} )");
}

How to include Authorization header in cURL POST HTTP Request in PHP?

You have most of the code…

CURLOPT_HTTPHEADER for curl_setopt() takes an array with each header as an element. You have one element with multiple headers.

You also need to add the Authorization header to your $header array.

$header = array();
$header[] = 'Content-length: 0';
$header[] = 'Content-type: application/json';
$header[] = 'Authorization: OAuth SomeHugeOAuthaccess_tokenThatIReceivedAsAString';

jQuery: how do I animate a div rotation?

I needed to rotate an object but have a call back function. Inspired by John Kern's answer I created this.

function animateRotate (object,fromDeg,toDeg,duration,callback){
        var dummy = $('<span style="margin-left:'+fromDeg+'px;">')
        $(dummy).animate({
            "margin-left":toDeg+"px"
        },
        {
            duration:duration,
            step: function(now,fx){
                $(object).css('transform','rotate(' + now + 'deg)');
                if(now == toDeg){
                    if(typeof callback == "function"){
                        callback();
                    }
                }
            }
        }
    )};

Doing this you can simply call the rotate on the object like so... (in my case I'm doing it on a disclosure triangle icon that has already been rotated by default to 270 degress and I'm rotating it another 90 degrees to 360 degrees at 1000 milliseconds. The final argument is the callback after the animation has finished.

animateRotate($(".disclosure_icon"),270,360,1000,function(){
                alert('finished rotate');
            });

Use CSS to remove the space between images

The best solution I've found for this is to contain them in a parent div, and give that div a font-size of 0.

ASP.NET MVC: What is the correct way to redirect to pages/actions in MVC?

1) When the user logs out (Forms signout in Action) I want to redirect to a login page.

public ActionResult Logout() {
    //log out the user
    return RedirectToAction("Login");
}

2) In a Controller or base Controller event eg Initialze, I want to redirect to another page (AbsoluteRootUrl + Controller + Action)

Why would you want to redirect from a controller init?

the routing engine automatically handles requests that come in, if you mean you want to redirect from the index action on a controller simply do:

public ActionResult Index() {
    return RedirectToAction("whateverAction", "whateverController");
}

How do you find out the caller function in JavaScript?

Try accessing this:

arguments.callee.caller.name

How to submit an HTML form without redirection

Using this snippet, you can submit the form and avoid redirection. Instead you can pass the success function as argument and do whatever you want.

function submitForm(form, successFn){
    if (form.getAttribute("id") != '' || form.getAttribute("id") != null){
        var id = form.getAttribute("id");
    } else {
        console.log("Form id attribute was not set; the form cannot be serialized");
    }

    $.ajax({
        type: form.method,
        url: form.action,
        data: $(id).serializeArray(),
        dataType: "json",
        success: successFn,
        //error: errorFn(data)
    });
}

And then just do:

var formElement = document.getElementById("yourForm");
submitForm(formElement, function() {
    console.log("Form submitted");
});

Spring not autowiring in unit tests with JUnit

I had same problem with Spring Boot 2.1.1 and JUnit 4
just added those annotations:

@RunWith( SpringRunner.class )
@SpringBootTest

and all went well.

For Junit 5:

@ExtendWith(SpringExtension.class)

source

How to parse string into date?

You can use:

SELECT CONVERT(datetime, '24.04.2012', 103) AS Date

Reference: CAST and CONVERT (Transact-SQL)

PHP mkdir: Permission denied problem

Don't set permissions to 777 when using mkdir in PHP

Link only answers are not considered good practice on StackOverflow, but the advice that is given here should generally NOT be followed up.

I would like to revert to this great answer on a similar question. I quote:

Please stop suggesting to use 777. You're making your file writeable by everyone, which pretty much means you lose all security that the permission system was designed for. If you suggest this, think about the consequences it may have on a poorly configured webserver: it would become incredibly easy to "hack" the website, by overwriting the files. So, don't.

Best way to copy a database (SQL Server 2008)

Below is what I do to copy a database from production env to my local env:

  1. Create an empty database in your local sql server
  2. Right click on the new database -> tasks -> import data
  3. In the SQL Server Import and Export Wizard, select product env's servername as data source. And select your new database as the destination data.

Filter Linq EXCEPT on properties

MoreLinq has something useful for this MoreLinq.Source.MoreEnumerable.ExceptBy

https://github.com/gsscoder/morelinq/blob/master/MoreLinq/ExceptBy.cs

namespace MoreLinq
{
    using System;
    using System.Collections.Generic;
    using System.Linq;

    static partial class MoreEnumerable
    {
        /// <summary>
        /// Returns the set of elements in the first sequence which aren't
        /// in the second sequence, according to a given key selector.
        /// </summary>
        /// <remarks>
        /// This is a set operation; if multiple elements in <paramref name="first"/> have
        /// equal keys, only the first such element is returned.
        /// This operator uses deferred execution and streams the results, although
        /// a set of keys from <paramref name="second"/> is immediately selected and retained.
        /// </remarks>
        /// <typeparam name="TSource">The type of the elements in the input sequences.</typeparam>
        /// <typeparam name="TKey">The type of the key returned by <paramref name="keySelector"/>.</typeparam>
        /// <param name="first">The sequence of potentially included elements.</param>
        /// <param name="second">The sequence of elements whose keys may prevent elements in
        /// <paramref name="first"/> from being returned.</param>
        /// <param name="keySelector">The mapping from source element to key.</param>
        /// <returns>A sequence of elements from <paramref name="first"/> whose key was not also a key for
        /// any element in <paramref name="second"/>.</returns>

        public static IEnumerable<TSource> ExceptBy<TSource, TKey>(this IEnumerable<TSource> first,
            IEnumerable<TSource> second,
            Func<TSource, TKey> keySelector)
        {
            return ExceptBy(first, second, keySelector, null);
        }

        /// <summary>
        /// Returns the set of elements in the first sequence which aren't
        /// in the second sequence, according to a given key selector.
        /// </summary>
        /// <remarks>
        /// This is a set operation; if multiple elements in <paramref name="first"/> have
        /// equal keys, only the first such element is returned.
        /// This operator uses deferred execution and streams the results, although
        /// a set of keys from <paramref name="second"/> is immediately selected and retained.
        /// </remarks>
        /// <typeparam name="TSource">The type of the elements in the input sequences.</typeparam>
        /// <typeparam name="TKey">The type of the key returned by <paramref name="keySelector"/>.</typeparam>
        /// <param name="first">The sequence of potentially included elements.</param>
        /// <param name="second">The sequence of elements whose keys may prevent elements in
        /// <paramref name="first"/> from being returned.</param>
        /// <param name="keySelector">The mapping from source element to key.</param>
        /// <param name="keyComparer">The equality comparer to use to determine whether or not keys are equal.
        /// If null, the default equality comparer for <c>TSource</c> is used.</param>
        /// <returns>A sequence of elements from <paramref name="first"/> whose key was not also a key for
        /// any element in <paramref name="second"/>.</returns>

        public static IEnumerable<TSource> ExceptBy<TSource, TKey>(this IEnumerable<TSource> first,
            IEnumerable<TSource> second,
            Func<TSource, TKey> keySelector,
            IEqualityComparer<TKey> keyComparer)
        {
            if (first == null) throw new ArgumentNullException("first");
            if (second == null) throw new ArgumentNullException("second");
            if (keySelector == null) throw new ArgumentNullException("keySelector");
            return ExceptByImpl(first, second, keySelector, keyComparer);
        }

        private static IEnumerable<TSource> ExceptByImpl<TSource, TKey>(this IEnumerable<TSource> first,
            IEnumerable<TSource> second,
            Func<TSource, TKey> keySelector,
            IEqualityComparer<TKey> keyComparer)
        {
            var keys = new HashSet<TKey>(second.Select(keySelector), keyComparer);
            foreach (var element in first)
            {
                var key = keySelector(element);
                if (keys.Contains(key))
                {
                    continue;
                }
                yield return element;
                keys.Add(key);
            }
        }
    }
}

How to delete from a table where ID is in a list of IDs?

delete from t
where id in (1, 4, 6, 7)

How do I set the timeout for a JAX-WS webservice client?

the easiest way to avoid slow retrieval of the remote WSDL when you instantiate your SEI is to not retrieve the WSDL from the remote service endpoint at runtime.

this means that you have to update your local WSDL copy any time the service provider makes an impacting change, but it also means that you have to update your local copy any time the service provider makes an impacting change.

When I generate my client stubs, I tell the JAX-WS runtime to annotate the SEI in such a way that it will read the WSDL from a pre-determined location on the classpath. by default the location is relative to the package location of the Service SEI


<wsimport
    sourcedestdir="${dao.helter.dir}/build/generated"
    destdir="${dao.helter.dir}/build/bin/generated"
    wsdl="${dao.helter.dir}/src/resources/schema/helter/helterHttpServices.wsdl"
    wsdlLocation="./wsdl/helterHttpServices.wsdl"
    package="com.helter.esp.dao.helter.jaxws"
    >
    <binding dir="${dao.helter.dir}/src/resources/schema/helter" includes="*.xsd"/>
</wsimport>
<copy todir="${dao.helter.dir}/build/bin/generated/com/helter/esp/dao/helter/jaxws/wsdl">
    <fileset dir="${dao.helter.dir}/src/resources/schema/helter" includes="*" />
</copy>

the wsldLocation attribute tells the SEI where is can find the WSDL, and the copy makes sure that the wsdl (and supporting xsd.. etc..) is in the correct location.

since the location is relative to the SEI's package location, we create a new sub-package (directory) called wsdl, and copy all the wsdl artifacts there.

all you have to do at this point is make sure you include all *.wsdl, *.xsd in addition to all *.class when you create your client-stub artifact jar file.

(in case your curious, the @webserviceClient annotation is where this wsdl location is actually set in the java code

@WebServiceClient(name = "httpServices", targetNamespace = "http://www.helter.com/schema/helter/httpServices", wsdlLocation = "./wsdl/helterHttpServices.wsdl")

What is the easiest way to clear a database from the CLI with manage.py in Django?

You can use the Django-Truncate library to delete all data of a table without destroying the table structure.

Example:

  1. First, install django-turncate using your terminal/command line:
pip install django-truncate
  1. Add "django_truncate" to your INSTALLED_APPS in the settings.py file:
INSTALLED_APPS = [
    ...
    'django_truncate',
]
  1. Use this command in your terminal to delete all data of the table from the app.
python manage.py truncate --apps app_name --models table_name