How to compile without warnings being treated as errors?

Remove -Werror from your Make or CMake files, as suggested in this post

Objective-C implicit conversion loses integer precision 'NSUInteger' (aka 'unsigned long') to 'int' warning

Doing the expicit casting to the "int" solves the problem in my case. I had the same issue. So:

int count = (int)[myColors count];

Why this "Implicit declaration of function 'X'"?

summation and your other functions are defined after they're used in main, and so the compiler has made a guess about it's signature; in other words, an implicit declaration has been assumed.

You should declare the function before it's used and get rid of the warning. In the C99 specification, this is an error.

Either move the function bodies before main, or include method signatures before main, e.g.:

#include <stdio.h>

int summation(int *, int *, int *);

int main()
{
    // ...

Property getters and setters

Setters and Getters apply to computed properties; such properties do not have storage in the instance - the value from the getter is meant to be computed from other instance properties. In your case, there is no x to be assigned.

Explicitly: "How can I do this without explicit backing ivars". You can't - you'll need something to backup the computed property. Try this:

class Point {
  private var _x: Int = 0             // _x -> backingX
  var x: Int {
    set { _x = 2 * newValue }
    get { return _x / 2 }
  }
}

Specifically, in the Swift REPL:

 15> var pt = Point()
pt: Point = {
  _x = 0
}
 16> pt.x = 10
 17> pt
$R3: Point = {
  _x = 20
}
 18> pt.x
$R4: Int = 10

What is "android:allowBackup"?

For this lint warning, as for all other lint warnings, note that you can get a fuller explanation than just what is in the one line error message; you don't have to search the web for more info.

If you are using lint via Eclipse, either open the lint warnings view, where you can select the lint error and see a longer explanation, or invoke the quick fix (Ctrl-1) on the error line, and one of the suggestions is "Explain this issue", which will also pop up a fuller explanation. If you are not using Eclipse, you can generate an HTML report from lint (lint --html <filename>) which includes full explanations next to the warnings, or you can ask lint to explain a particular issue. For example, the issue related to allowBackup has the id AllowBackup (shown at the end of the error message), so the fuller explanation is:

$ ./lint --show AllowBackup
AllowBackup
-----------
Summary: Ensure that allowBackup is explicitly set in the application's
manifest

Priority: 3 / 10
Severity: Warning
Category: Security

The allowBackup attribute determines if an application's data can be backed up and restored, as documented here.

By default, this flag is set to true. When this flag is set to true, application data can be backed up and restored by the user using adb backup and adb restore.

This may have security consequences for an application. adb backup allows users who have enabled USB debugging to copy application data off of the device. Once backed up, all application data can be read by the user. adb restore allows creation of application data from a source specified by the user. Following a restore, applications should not assume that the data, file permissions, and directory permissions were created by the application itself.

Setting allowBackup="false" opts an application out of both backup and restore.

To fix this warning, decide whether your application should support backup and explicitly set android:allowBackup=(true|false)

Click here for More information

How to disable GCC warnings for a few lines of code

I had same issue with external libraries like ROS headers. I like to use following options in CMakeLists.txt for stricter compilation:

set(CMAKE_CXX_FLAGS "-std=c++0x -Wall -Wextra -Wstrict-aliasing -pedantic -Werror -Wunreachable-code ${CMAKE_CXX_FLAGS}")

However doing this causes all kind of pedantic errors in externally included libraries as well. The solution is to disable all pedantic warnings before you include external libraries and re-enable like this:

//save compiler switches
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"

//Bad headers with problem goes here
#include <ros/ros.h>
#include <sensor_msgs/LaserScan.h>

//restore compiler switches
#pragma GCC diagnostic pop

error C2220: warning treated as error - no 'object' file generated

Go to project properties -> configurations properties -> C/C++ -> treats warning as error -> No (/WX-).

What does "control reaches end of non-void function" mean?

I had the same problem. My code below didn't work, but when I replaced the last "if" with "else", it works. The error was: may reach end of non-void function.

int shifted(char key_letter)
  {
        if(isupper(key_letter))
        {
            return key_letter - 'A'; 
        }

        if(islower(key_letter)   //<----------- doesn't work, replace with else

        {                                            


            return key_letter - 'a'; 
        }

  }

What is the list of valid @SuppressWarnings warning names in Java?

I noticed that //noinspection can be auto-generated in IntelliJ

• make sure you have not already a plan @SuppressWarninigs before the statement
• Now you can auto-generate the specific //noinspection by hitting Alt+Enter when you have the warning selected and then use the right arrow key to see the Suppress for ... option

Ended up here when I wanted to suppress a "switch has too few case labels" warning from IntelliJ. I did not find a complete List for IntelliJ's @SuppressWarning support but //noinspection did the trick for me.

Compiler warning - suggest parentheses around assignment used as truth value

While that particular idiom is common, even more common is for people to use = when they mean ==. The convention when you really mean the = is to use an extra layer of parentheses:

while ((list = list->next)) { // yes, it's an assignment

warning: implicit declaration of function

The right way is to declare function prototype in header.

Example

main.h

#ifndef MAIN_H
#define MAIN_H

int some_main(const char *name);

#endif

main.c

#include "main.h"

int main()
{
    some_main("Hello, World\n");
}

int some_main(const char *name)
{
    printf("%s", name);
}

Alternative with one file (main.c)

static int some_main(const char *name);

int some_main(const char *name)
{
    // do something
}

Java Class.cast() vs. cast operator

Personally, I've used this before to build a JSON to POJO converter. In the case that the JSONObject processed with the function contains an array or nested JSONObjects (implying that the data here isn't of a primitive type or String), I attempt to invoke the setter method using class.cast() in this fashion:

public static Object convertResponse(Class<?> clazz, JSONObject readResultObject) {
    ...
    for(Method m : clazz.getMethods()) {
        if(!m.isAnnotationPresent(convertResultIgnore.class) && 
            m.getName().toLowerCase().startsWith("set")) {
        ...
        m.invoke(returnObject,  m.getParameters()[0].getClass().cast(convertResponse(m.getParameters()[0].getType(), readResultObject.getJSONObject(key))));
    }
    ...
}

Not sure if this is extremely helpful, but as said here before, reflection is one of the very few legitimate use case of class.cast() I can think of, at least you have another example now.

How do you disable the unused variable warnings coming out of gcc in 3rd party code I do not wish to edit?

-Wall and -Wextra sets the stage in GCC and the subsequent -Wno-unused-variable may not take effect. For example, if you have:

CFLAGS += -std=c99 -pedantic -pedantic-errors -Werror -g0 -Os \ -fno-strict-overflow -fno-strict-aliasing \ -Wall -Wextra \ -pthread \ -Wno-unused-label \ -Wno-unused-function \ -Wno-unused-parameter \ -Wno-unused-variable \ $(INC)

then GCC sees the instruction -Wall -Wextra and seems to ignore -Wno-unused-variable

This can instead look like this below and you get the desired effect of not being stopped in your compile on the unused variable:

CFLAGS += -std=c99 -pedantic -pedantic-errors -Werror -g0 -Os \ -fno-strict-overflow -fno-strict-aliasing \ -pthread \ -Wno-unused-label \ -Wno-unused-function \ $(INC)

There is a good reason it is called a "warning" vs an "error". Failing the compile just because you code is not complete (say you are stubbing the algorithm out) can be defeating.

Multi-character constant warnings

If you want to disable this warning it is important to know that there are two related warning parameters in GCC and Clang: GCC Compiler options -wno-four-char-constants and -wno-multichar

SQL Server stored procedure parameters

CREATE PROCEDURE GetTaskEvents
@TaskName varchar(50),
@Id INT
AS
BEGIN
-- SP Logic
END

Procedure Calling

DECLARE @return_value nvarchar(50)

EXEC  @return_value = GetTaskEvents
        @TaskName = 'TaskName',
        @Id =2  

SELECT  'Return Value' = @return_value

How to copy a map?

I'd use recursion just in case so you can deep copy the map and avoid bad surprises in case you were to change a map element that is a map itself.

Here's an example in a utils.go:

package utils

func CopyMap(m map[string]interface{}) map[string]interface{} {
    cp := make(map[string]interface{})
    for k, v := range m {
        vm, ok := v.(map[string]interface{})
        if ok {
            cp[k] = CopyMap(vm)
        } else {
            cp[k] = v
        }
    }

    return cp
}

And its test file (i.e. utils_test.go):

package utils

import (
    "testing"

    "github.com/stretchr/testify/require"
)

func TestCopyMap(t *testing.T) {
    m1 := map[string]interface{}{
        "a": "bbb",
        "b": map[string]interface{}{
            "c": 123,
        },
    }

    m2 := CopyMap(m1)

    m1["a"] = "zzz"
    delete(m1, "b")

    require.Equal(t, map[string]interface{}{"a": "zzz"}, m1)
    require.Equal(t, map[string]interface{}{
        "a": "bbb",
        "b": map[string]interface{}{
            "c": 123,
        },
    }, m2)
}

It should easy enough to adapt if you need the map key to be something else instead of a string.

What's the best way to determine the location of the current PowerShell script?

I found that the older solutions posted here didn't work for me on PowerShell V5. I came up with this:

try {
    $scriptPath = $PSScriptRoot
    if (!$scriptPath)
    {
        if ($psISE)
        {
            $scriptPath = Split-Path -Parent -Path $psISE.CurrentFile.FullPath
        }
        else {
            Write-Host -ForegroundColor Red "Cannot resolve script file's path"
            exit 1
        }
    }
}
catch {
    Write-Host -ForegroundColor Red "Caught Exception: $($Error[0].Exception.Message)"
    exit 2
}

Write-Host "Path: $scriptPath"

How to fix 'Notice: Undefined index:' in PHP form action

Change $_POST to $_FILES and make sure your enctype is "multipart/form-data"

Is your input field actually in a form?

<form method="POST" action="update.php">
    <input type="hidden" name="filename" value="test" />
</form>

How do you turn a Mongoose document into a plain object?

Another way to do this is to tell Mongoose that all you need is a plain JavaScript version of the returned doc by using lean() in the query chain. That way Mongoose skips the step of creating the full model instance and you directly get a doc you can modify:

MyModel.findOne().lean().exec(function(err, doc) {
    doc.addedProperty = 'foobar';
    res.json(doc);
});

Add a reference column migration in Rails 4

Rails 4.x

When you already have users and uploads tables and wish to add a new relationship between them.

All you need to do is: just generate a migration using the following command:

rails g migration AddUserToUploads user:references

Which will create a migration file as:

class AddUserToUploads < ActiveRecord::Migration
  def change
    add_reference :uploads, :user, index: true
  end
end

Then, run the migration using rake db:migrate. This migration will take care of adding a new column named user_id to uploads table (referencing id column in users table), PLUS it will also add an index on the new column.

UPDATE [For Rails 4.2]

Rails can’t be trusted to maintain referential integrity; relational databases come to our rescue here. What that means is that we can add foreign key constraints at the database level itself and ensure that database would reject any operation that violates this set referential integrity. As @infoget commented, Rails 4.2 ships with native support for foreign keys(referential integrity). It's not required but you might want to add foreign key(as it's very useful) to the reference that we created above.

To add foreign key to an existing reference, create a new migration to add a foreign key:

class AddForeignKeyToUploads < ActiveRecord::Migration
  def change
    add_foreign_key :uploads, :users
  end
end

To create a completely brand new reference with a foreign key(in Rails 4.2), generate a migration using the following command:

rails g migration AddUserToUploads user:references

which will create a migration file as:

class AddUserToUploads < ActiveRecord::Migration
  def change
    add_reference :uploads, :user, index: true
    add_foreign_key :uploads, :users
  end
end

This will add a new foreign key to the user_id column of the uploads table. The key references the id column in users table.

NOTE: This is in addition to adding a reference so you still need to create a reference first then foreign key (you can choose to create a foreign key in the same migration or a separate migration file). Active Record only supports single column foreign keys and currently only mysql, mysql2 and PostgreSQL adapters are supported. Don't try this with other adapters like sqlite3, etc. Refer to Rails Guides: Foreign Keys for your reference.

Batch script to find and replace a string in text file within a minute for files up to 12 MB

Give this a shot:

@echo off
setlocal

call :FindReplace "findstr" "replacestr" input.txt

exit /b 

:FindReplace <findstr> <replstr> <file>
set tmp="%temp%\tmp.txt"
If not exist %temp%\_.vbs call :MakeReplace
for /f "tokens=*" %%a in ('dir "%3" /s /b /a-d /on') do (
  for /f "usebackq" %%b in (`Findstr /mic:"%~1" "%%a"`) do (
    echo(&Echo Replacing "%~1" with "%~2" in file %%~nxa
    <%%a cscript //nologo %temp%\_.vbs "%~1" "%~2">%tmp%
    if exist %tmp% move /Y %tmp% "%%~dpnxa">nul
  )
)
del %temp%\_.vbs
exit /b

:MakeReplace
>%temp%\_.vbs echo with Wscript
>>%temp%\_.vbs echo set args=.arguments
>>%temp%\_.vbs echo .StdOut.Write _
>>%temp%\_.vbs echo Replace(.StdIn.ReadAll,args(0),args(1),1,-1,1)
>>%temp%\_.vbs echo end with

How to make a parent div auto size to the width of its children divs

Your interior <div> elements should likely both be float:left. Divs size to 100% the size of their container width automatically. Try using display:inline-block instead of width:auto on the container div. Or possibly float:left the container and also apply overflow:auto. Depends on what you're after exactly.

WooCommerce return product object by id

global $woocommerce;
var_dump($woocommerce->customer->get_country());
foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
    $product = new WC_product($cart_item['product_id']);
    var_dump($product);
}

Bootstrap 3 - How to load content in modal body via AJAX?

create an empty modal box on the current page and below is the ajax call you can see how to fetch the content in result from another html page.

 $.ajax({url: "registration.html", success: function(result){
            //alert("success"+result);
              $("#contentBody").html(result);
            $("#myModal").modal('show'); 

        }});

once the call is done you will get the content of the page by the result to then you can insert the code in you modal's content id using.

You can call controller and get the page content and you can show that in your modal.

below is the example of Bootstrap 3 modal in that we are loading content from registration.html page...

index.html
------------------------------------------------
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>

<script type="text/javascript">
function loadme(){
    //alert("loadig");

    $.ajax({url: "registration.html", success: function(result){
        //alert("success"+result);
          $("#contentBody").html(result);
        $("#myModal").modal('show'); 

    }});
}
</script>
</head>
<body>

<!-- Trigger the modal with a button -->
<button type="button" class="btn btn-info btn-lg" onclick="loadme()">Load me</button>


<!-- Modal -->
<div id="myModal" class="modal fade" role="dialog">
  <div class="modal-dialog">

    <!-- Modal content-->
    <div class="modal-content" >
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal">&times;</button>
        <h4 class="modal-title">Modal Header</h4>
      </div>
      <div class="modal-body" id="contentBody">

      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
      </div>
    </div>

  </div>
</div>

</body>
</html>

registration.html
-------------------- 
<!DOCTYPE html>
<html>
<style>
body {font-family: Arial, Helvetica, sans-serif;}

form {
    border: 3px solid #f1f1f1;
    font-family: Arial;
}

.container {
    padding: 20px;
    background-color: #f1f1f1;
    width: 560px;
}

input[type=text], input[type=submit] {
    width: 100%;
    padding: 12px;
    margin: 8px 0;
    display: inline-block;
    border: 1px solid #ccc;
    box-sizing: border-box;
}

input[type=checkbox] {
    margin-top: 16px;
}

input[type=submit] {
    background-color: #4CAF50;
    color: white;
    border: none;
}

input[type=submit]:hover {
    opacity: 0.8;
}
</style>
<body>

<h2>CSS Newsletter</h2>

<form action="/action_page.php">
  <div class="container">
    <h2>Subscribe to our Newsletter</h2>
    <p>Lorem ipsum text about why you should subscribe to our newsletter blabla. Lorem ipsum text about why you should subscribe to our newsletter blabla.</p>
  </div>

  <div class="container" style="background-color:white">
    <input type="text" placeholder="Name" name="name" required>
    <input type="text" placeholder="Email address" name="mail" required>
    <label>
      <input type="checkbox" checked="checked" name="subscribe"> Daily Newsletter
    </label>
  </div>

  <div class="container">
    <input type="submit" value="Subscribe">
  </div>
</form>

</body>
</html>

PHP 7: Missing VCRUNTIME140.dll

If you've followed Adam's instructions and you're still getting this error make sure you've installed the right variants (x86 or x64).

I had VC14x64 with PHP7x86 and I still got this error. Changing PHP7 to x64 fixed it. It's easy to miss you accidentally installed the wrong version.

What is the difference between the 'COPY' and 'ADD' commands in a Dockerfile?

COPY is

Same as 'ADD', but without the tar and remote URL handling.

Reference straight from the source code.

Function return value in PowerShell

The existing answers are correct, but sometimes you aren't actually returning something explicitly with a Write-Output or a return, yet there is some mystery value in the function results. This could be the output of a builtin function like New-Item

PS C:\temp> function ContrivedFolderMakerFunction {
>>    $folderName = [DateTime]::Now.ToFileTime()
>>    $folderPath = Join-Path -Path . -ChildPath $folderName
>>    New-Item -Path $folderPath -ItemType Directory
>>    return $true
>> }
PS C:\temp> $result = ContrivedFolderMakerFunction
PS C:\temp> $result


    Directory: C:\temp


Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----         2/9/2020   4:32 PM                132257575335253136
True

All that extra noise of the directory creation is being collected and emitted in the output. The easy way to mitigate this is to add | Out-Null to the end of the New-Item statement, or you can assign the result to a variable and just not use that variable. It would look like this...

PS C:\temp> function ContrivedFolderMakerFunction {
>>    $folderName = [DateTime]::Now.ToFileTime()
>>    $folderPath = Join-Path -Path . -ChildPath $folderName
>>    New-Item -Path $folderPath -ItemType Directory | Out-Null
>>    # -or-
>>    $throwaway = New-Item -Path $folderPath -ItemType Directory 
>>    return $true
>> }
PS C:\temp> $result = ContrivedFolderMakerFunction
PS C:\temp> $result
True

New-Item is probably the more famous of these, but others include all of the StringBuilder.Append*() methods, as well as the SqlDataAdapter.Fill() method.

Excel VBA Run-time error '424': Object Required when trying to copy TextBox

The issue is with this line

 xlo.Worksheets(1).Cells(2, 2) = TextBox1.Text

You have the textbox defined at some other location which you are not using here. Excel is unable to find the textbox object in the current sheet while this textbox was defined in xlw.

Hence replace this with

 xlo.Worksheets(1).Cells(2, 2) = worksheets("xlw").TextBox1.Text 

How to disable copy/paste from/to EditText

You may try android:focusableInTouchMode="false".

How to install Android Studio on Ubuntu?

Android Studio is now integrated in JetBrains Toolbox:

This free tool allows to easily install all JetBrains products, and Android Studio as well. Upgrade is automatic.

On Ubuntu, this tools requires FUSE (Filesystem in Userspace)

unable to remove file that really exists - fatal: pathspec ... did not match any files

Personally I stumbled on a similar error message in this scenario:

I created a folder that has been empty, so naturally as long as it is empty, typing git add * will not take this empty folder in consideration. So when I tried to run git rm -r * or simply git rm my_empty_folder/ -r, I got that error message.

The solution is to simply remove it without git: rm -r my_empty_folder/ or create a data file within this folder and then add it (git add my_no_long_empty_folder)

List all kafka topics

Please use kafka-topics.sh --list --bootstrap-server localhost:9092 to list down all topics

How to SELECT WHERE NOT EXIST using LINQ?

First of all, I suggest to modify a bit your sql query:

 select * from shift 
 where shift.shiftid not in (select employeeshift.shiftid from employeeshift 
                             where employeeshift.empid = 57);

This query provides same functionality. If you want to get the same result with LINQ, you can try this code:

//Variable dc has DataContext type here
//Here we get list of ShiftIDs from employeeshift table
List<int> empShiftIds = dc.employeeshift.Where(p => p.EmpID = 57).Select(s => s.ShiftID).ToList();

//Here we get the list of our shifts
List<shift> shifts = dc.shift.Where(p => !empShiftIds.Contains(p.ShiftId)).ToList();

How to read file with space separated values in pandas

you can use regex as the delimiter:

pd.read_csv("whitespace.csv", header=None, delimiter=r"\s+")

Dockerfile if else condition with external arguments

You can use the conditional system that best fits your needs.

Dockerfile

ARG ENV

FROM foo as base

ARG ENV

# run common
RUN ...

# For long running tasks that would slow down deployments
RUN if [[ "$ENV" == "dev" ]] ; then \
        yum install -y lots of big dev packages ; \
    fi

# Build dev image
FROM base as image-dev

RUN ...
COPY ...

# Build prod image
FROM base as image-prod

RUN ...
COPY ...

FROM image-$ENV AS final

Note that we define ENV twice - you need to define ENV globally, and in each image where it is used.

Use docker:

docker build -t my_docker . --build-arg ENV="dev"

Use docker-compose:

version: '3'

services:

  dev:
    container_name: dev
    ports:
      - 3000:8080
    volumes:
      - ./:/var/task
    tty: true
    build:
      context: .
      dockerfile: Dockerfile
      args:
        ENV: dev

docker-compose build --no-cache dev && docker-compose up dev

String or binary data would be truncated. The statement has been terminated

Specify a size for the item and warehouse like in the [dbo].[testing1] FUNCTION

@trackingItems1 TABLE (
item       nvarchar(25)  NULL, -- 25 OR equal size of your item column
warehouse   nvarchar(25) NULL, -- same as above
price int   NULL

) 

Since in MSSQL only saying only nvarchar is equal to nvarchar(1) hence the values of the column from the stock table are truncated

Extract directory path and filename

bash to get file name

fspec="/exp/home1/abc.txt" 
filename="${fspec##*/}"  # get filename
dirname="${fspec%/*}" # get directory/path name

other ways

awk

$ echo $fspec | awk -F"/" '{print $NF}'
abc.txt

sed

$ echo $fspec | sed 's/.*\///'
abc.txt

using IFS

$ IFS="/"
$ set -- $fspec
$ eval echo \${${#@}}
abc.txt

Could not load type from assembly error

When I run into such problem, I find FUSLOGVW tool very helpful. It is checking assembly binding information and logs it for you. Sometimes the libraries are missing, sometimes GAC has different versions that are being loaded. Sometimes the platform of referenced libraries is causing the problems. This tool makes it clear how the dependencies' bindings are being resolved and this may really help you to investigate/debug your problem.

Fusion Log Viewer / fuslogvw / Assembly Binding Log Viewer. Check more/download here: http://msdn.microsoft.com/en-us/library/e74a18c4.aspx.

How do I rename a column in a SQLite database table?

Recently I had to do that in SQLite3 with a table named points with the colunms id, lon, lat. Erroneusly, when the table was imported, the values for latitude where stored in the lon column and viceversa, so an obvious fix would be to rename those columns. So the trick was:

create table points_tmp as select id, lon as lat, lat as lon from points;
drop table points;
alter table points_tmp rename to points;

I hope this would be useful for you!

Java HTTP Client Request with defined timeout

If you are using Http Client version 4.3 and above you should be using this:

RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30 * 1000).build();
HttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();

Reading an integer from user input

You could create your own ReadInt function, that only allows numbers (this function is probably not the best way to go about this, but does the job)

public static int ReadInt()
    {
        string allowedChars = "0123456789";

        ConsoleKeyInfo read = new ConsoleKeyInfo();
        List<char> outInt = new List<char>();

        while(!(read.Key == ConsoleKey.Enter && outInt.Count > 0))
        {
            read = Console.ReadKey(true);
            if (allowedChars.Contains(read.KeyChar.ToString()))
            {
                outInt.Add(read.KeyChar);
                Console.Write(read.KeyChar.ToString());
            }
            if(read.Key == ConsoleKey.Backspace)
            {
                if(outInt.Count > 0)
                {
                    outInt.RemoveAt(outInt.Count - 1);
                    Console.CursorLeft--;
                    Console.Write(" ");
                    Console.CursorLeft--;
                }
            }
        }
        Console.SetCursorPosition(0, Console.CursorTop + 1);
        return int.Parse(new string(outInt.ToArray()));
    }

Closing Excel Application Process in C# after Data Access

I met the same problems and tried many methods to solve it but doesn't work. Finally , I found the by my way. Some reference enter link description here

Hope my code can help someone future. I have been spent more than two days to solve it. Below is my Code:

//get current in useing excel
            Process[] excelProcsOld = Process.GetProcessesByName("EXCEL");
            Excel.Application myExcelApp = null;
            Excel.Workbooks excelWorkbookTemplate = null;
            Excel.Workbook excelWorkbook = null;
try{
    //DO sth using myExcelApp , excelWorkbookTemplate, excelWorkbook
}
catch (Exception ex ){
}
finally
            {
                //Compare the EXCEL ID and Kill it 
                Process[] excelProcsNew = Process.GetProcessesByName("EXCEL");
                foreach (Process procNew in excelProcsNew)
                {
                    int exist = 0;
                    foreach (Process procOld in excelProcsOld)
                    {
                        if (procNew.Id == procOld.Id)
                        {
                            exist++;
                        }
                    }
                    if (exist == 0)
                    {
                        procNew.Kill();
                    }        
                }
            }

How do I terminate a thread in C++11?

This question actually have more deep nature and good understanding of the multithreading concepts in general will provide you insight about this topic. In fact there is no any language or any operating system which provide you facilities for asynchronous abruptly thread termination without warning to not use them. And all these execution environments strongly advise developer or even require build multithreading applications on the base of cooperative or synchronous thread termination. The reason for this common decisions and advices is that all they are built on the base of the same general multithreading model.

Let's compare multiprocessing and multithreading concepts to better understand advantages and limitations of the second one.

Multiprocessing assumes splitting of the entire execution environment into set of completely isolated processes controlled by the operating system. Process incorporates and isolates execution environment state including local memory of the process and data inside it and all system resources like files, sockets, synchronization objects. Isolation is a critically important characteristic of the process, because it limits the faults propagation by the process borders. In other words, no one process can affects the consistency of any another process in the system. The same is true for the process behaviour but in the less restricted and more blur way. In such environment any process can be killed in any "arbitrary" moment, because firstly each process is isolated, secondly, operating system have full knowledges about all resources used by process and can release all of them without leaking, and finally process will be killed by OS not really in arbitrary moment, but in the number of well defined points where the state of the process is well known.

In contrast, multithreading assumes running multiple threads in the same process. But all this threads are share the same isolation box and there is no any operating system control of the internal state of the process. As a result any thread is able to change global process state as well as corrupt it. At the same moment the points in which the state of the thread is well known to be safe to kill a thread completely depends on the application logic and are not known neither for operating system nor for programming language runtime. As a result thread termination at the arbitrary moment means killing it at arbitrary point of its execution path and can easily lead to the process-wide data corruption, memory and handles leakage, threads leakage and spinlocks and other intra-process synchronization primitives leaved in the closed state preventing other threads in doing progress.

Due to this the common approach is to force developers to implement synchronous or cooperative thread termination, where the one thread can request other thread termination and other thread in well-defined point can check this request and start the shutdown procedure from the well-defined state with releasing of all global system-wide resources and local process-wide resources in the safe and consistent way.

How can I fill a column with random numbers in SQL? I get the same value in every row

While I do love using CHECKSUM, I feel that a better way to go is using NEWID(), just because you don't have to go through a complicated math to generate simple numbers .

ROUND( 1000 *RAND(convert(varbinary, newid())), 0)

You can replace the 1000 with whichever number you want to set as the limit, and you can always use a plus sign to create a range, let's say you want a random number between 100 and 200, you can do something like :

100 + ROUND( 100 *RAND(convert(varbinary, newid())), 0)

Putting it together in your query :

UPDATE CattleProds 
SET SheepTherapy= ROUND( 1000 *RAND(convert(varbinary, newid())), 0)
WHERE SheepTherapy IS NULL

Get the records of last month in SQL server

WHERE 
    date_created >= DATEADD(MONTH, DATEDIFF(MONTH, 31, CURRENT_TIMESTAMP), 0)
    AND date_created < DATEADD(MONTH, DATEDIFF(MONTH, 0, CURRENT_TIMESTAMP), 0)

No module named MySQLdb

On OSX these commands worked for me

brew install mysql-connector-c 
pip install MySQL-python

Popup window in PHP?

For a popup javascript is required. Put this in your header:

<script>
function myFunction()
{
alert("I am an alert box!"); // this is the message in ""
}
</script>

And this in your body:

<input type="button" onclick="myFunction()" value="Show alert box">

When the button is pressed a box pops up with the message set in the header.

This can be put in any html or php file without the php tags.

-----EDIT-----

To display it using php try this:

<?php echo '<script>myfunction()</script>'; ?>

It may not be 100% correct but the principle is the same.

To display different messages you can either create lots of functions or you can pass a variable in to the function when you call it.

Init array of structs in Go

It looks like you are trying to use (almost) straight up C code here. Go has a few differences.

• First off, you can't initialize arrays and slices as const. The term const has a different meaning in Go, as it does in C. The list should be defined as var instead.
• Secondly, as a style rule, Go prefers basenameOpts as opposed to basename_opts.
• There is no char type in Go. You probably want byte (or rune if you intend to allow unicode codepoints).
• The declaration of the list must have the assignment operator in this case. E.g.: var x = foo.
• Go's parser requires that each element in a list declaration ends with a comma. This includes the last element. The reason for this is because Go automatically inserts semi-colons where needed. And this requires somewhat stricter syntax in order to work.

For example:

type opt struct {
    shortnm      byte
    longnm, help string
    needArg      bool
}

var basenameOpts = []opt { 
    opt {
        shortnm: 'a', 
        longnm: "multiple", 
        needArg: false, 
        help: "Usage for a",
    },
    opt {
        shortnm: 'b', 
        longnm: "b-option", 
        needArg: false, 
        help: "Usage for b",
    },
}

An alternative is to declare the list with its type and then use an init function to fill it up. This is mostly useful if you intend to use values returned by functions in the data structure. init functions are run when the program is being initialized and are guaranteed to finish before main is executed. You can have multiple init functions in a package, or even in the same source file.

    type opt struct {
        shortnm      byte
        longnm, help string
        needArg      bool
    }

    var basenameOpts []opt

    func init() { 
        basenameOpts = []opt{
            opt {
                shortnm: 'a', 
                longnm: "multiple", 
                needArg: false, 
                help: "Usage for a",
            },
            opt {
                shortnm: 'b', 
                longnm: "b-option", 
                needArg: false, 
               help: "Usage for b",
            },
        }
    }

Since you are new to Go, I strongly recommend reading through the language specification. It is pretty short and very clearly written. It will clear a lot of these little idiosyncrasies up for you.

How can I remove a button or make it invisible in Android?

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/activity_register_header"
    android:minHeight="50dp"
    android:orientation="vertical"
    android:visibility="gone" />

Try This Code

Visibility works fine in this code

Return Max Value of range that is determined by an Index & Match lookup

You don't need an index match formula. You can use this array formula. You have to press CTL + SHIFT + ENTER after you enter the formula.

=MAX(IF((A1:A6=A10)*(B1:B6=B10),C1:F6))

SNAPSHOT

CreateProcess error=2, The system cannot find the file specified

The complete first argument of exec is being interpreted as the executable. Use

p = rt.exec(new String[] {"winrar.exe", "x", "h:\\myjar.jar", "*.*", "h:\\new" }
            null, 
            dir);

How to properly use unit-testing's assertRaises() with NoneType objects?

The problem is the TypeError gets raised 'before' assertRaises gets called since the arguments to assertRaises need to be evaluated before the method can be called. You need to pass a lambda expression like:

self.assertRaises(TypeError, lambda: self.testListNone[:1])

Travel/Hotel API's?

Check out api.hotelsbase.org - its a free xml hotel api No images as of yet though

How to use DbContext.Database.SqlQuery<TElement>(sql, params) with stored procedure? EF Code First CTP5

I did mine with EF 6.x like this:

using(var db = new ProFormDbContext())
            {
                var Action = 1; 
                var xNTID = "A239333";

                var userPlan = db.Database.SqlQuery<UserPlan>(
                "AD.usp_UserPlanInfo @Action, @NTID", //, @HPID",
                new SqlParameter("Action", Action),
                new SqlParameter("NTID", xNTID)).ToList();


            }

Don't double up on sqlparameter some people get burned doing this to their variable

var Action = new SqlParameter("@Action", 1);  // Don't do this, as it is set below already.

Open Source HTML to PDF Renderer with Full CSS Support

Try ABCpdf from webSupergoo. It's a commercial solution, not open source, but the standard edition can be obtained free of charge and will do what you are asking.

ABCpdf fully supports HTML and CSS, live forms and live links. It also uses Microsoft XML Core Services (MSXML) while rendering, so the results should match exactly what you see in Internet Explorer.

The on-line demo can be used to test HTML to PDF rendering without needing to install any software. See: http://www.abcpdfeditor.com/

The following C# code example shows how to render a single page HTML document.

Doc theDoc = new Doc();
theDoc.AddImageUrl("http://www.example.com/");
theDoc.Save("htmlimport.pdf");
theDoc.Clear();

To render multiple pages you'll need the AddImageToChain function, documented here: http://www.websupergoo.com/helppdf7net/source/5-abcpdf6/doc/1-methods/addimagetochain.htm

How to enable CORS in ASP.NET Core

Applies to .NET Core 1 and .Net Core 2 (further down)

If using .Net-Core 1.1

Unfortunately the docs are very confusing in this specific case. So I'll make it dead-simple:

• Add Microsoft.AspNetCore.Cors nuget package to your project
• In ConfigureServices method, add services.AddCors();

• In Configure method, before calling app.UseMvc() and app.UseStaticFiles(), add:

  app.UseCors(builder => builder
      .AllowAnyOrigin()
      .AllowAnyMethod()
      .AllowAnyHeader()
      .AllowCredentials());
  

That's it. Every client has access to your ASP.NET Core Website/API.

---

If using .Net-Core 2.0

• Add Microsoft.AspNetCore.Cors nuget package to your project

• in ConfigureServices method, before calling services.AddMvc(), add:

   services.AddCors(options =>
      {
          options.AddPolicy("AllowAll",
              builder =>
              {
                  builder
                  .AllowAnyOrigin() 
                  .AllowAnyMethod()
                  .AllowAnyHeader()
                  .AllowCredentials();
              });
      });
  

• (Important) In Configure method, before calling app.UseMvc(), add app.UseCors("AllowAll");

  AllowAll is the policy name which we need to mention in app.UserCors. It could be any name.

Regex to extract URLs from href attribute in HTML with Python

import re

url = '<p>Hello World</p><a href="http://example.com">More Examples</a><a href="http://example2.com">Even More Examples</a>'

urls = re.findall('https?://(?:[-\w.]|(?:%[\da-fA-F]{2}))+', url)

>>> print urls
['http://example.com', 'http://example2.com']

Javascript getElementsByName.value not working

You have mentioned Wrong id

alert(document.getElementById("name").value);

if you want to use name attribute then

alert(document.getElementsByName("username")[0].value);

Updates:

input type="text" id="name" name="username"  

id is different from name

Python - converting a string of numbers into a list of int

Try this :

import re
[int(s) for s in re.split('[\s,]+',example_string)]

CSS Margin: 0 is not setting to 0

you should have either (or both):

1. a paddding != 0 on body
2. a margin !=0 on #header

try

html, #header {
    margin: 0 !important;
    padding: 0 !important;
}

The margin is the "space" outside the box, the padding is the "space" inside the box (between the border and the content). The !important prevent overriding of property by latter rules.

mysql_config not found when installing mysqldb python interface

If you're on macOS and already installed [email protected] via brew install:

1. brew install mysql-connector-c
2. brew unlink [email protected]
3. brew link --overwrite --dry-run [email protected] first, to see what symlinks are getting overwritten
4. brew link --overwrite --force [email protected] to actually overwrite mysql-related symlinks with [email protected]
5. pip install mysqlclient

Spring: How to inject a value to static field?

First of all, public static non-final fields are evil. Spring does not allow injecting to such fields for a reason.

Your workaround is valid, you don't even need getter/setter, private field is enough. On the other hand try this:

@Value("${my.name}")
public void setPrivateName(String privateName) {
    Sample.name = privateName;
}  

(works with @Autowired/@Resource). But to give you some constructive advice: Create a second class with private field and getter instead of public static field.

Uploading Images to Server android

Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, 1);

ABOVE CODE TO SELECT IMAGE FROM GALLERY

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 1)
        if (resultCode == Activity.RESULT_OK) {
            Uri selectedImage = data.getData();

            String filePath = getPath(selectedImage);
            String file_extn = filePath.substring(filePath.lastIndexOf(".") + 1);
            image_name_tv.setText(filePath);

            try {
                if (file_extn.equals("img") || file_extn.equals("jpg") || file_extn.equals("jpeg") || file_extn.equals("gif") || file_extn.equals("png")) {
                    //FINE
                } else {
                    //NOT IN REQUIRED FORMAT
                }
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
}

public String getPath(Uri uri) {
    String[] projection = {MediaColumns.DATA};
    Cursor cursor = managedQuery(uri, projection, null, null, null);
    column_index = cursor
            .getColumnIndexOrThrow(MediaColumns.DATA);
    cursor.moveToFirst();
    imagePath = cursor.getString(column_index);

    return cursor.getString(column_index);
}

NOW POST THE DATA USING MULTIPART FORM DATA

HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("LINK TO SERVER");

Multipart FORM DATA

MultipartEntity mpEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);
if (filePath != null) {
    File file = new File(filePath);
    Log.d("EDIT USER PROFILE", "UPLOAD: file length = " + file.length());
    Log.d("EDIT USER PROFILE", "UPLOAD: file exist = " + file.exists());
    mpEntity.addPart("avatar", new FileBody(file, "application/octet"));
}

FINALLY POST DATA TO SERVER

httppost.setEntity(mpEntity);
HttpResponse response = httpclient.execute(httppost);

Send values from one form to another form

Form1 Code :

private void button1_Click(object sender, EventArgs e)
{
            Form2 f2 = new Form2();
            f2.ShowDialog();
            MessageBox.Show("Form1 Message :"+Form2.t.Text); //can put label also in form 1 to show the value got from form2
}

Form2 Code :

        public Form2()
        {
            InitializeComponent();
            t = textBox1;                        //Initialize with static textbox
        }
        public static TextBox t=new TextBox();   //make static to get the same value as inserted
        private void button1_Click(object sender, EventArgs e)
        {

            this.Close();

        }

It Works!

Converting a string to a date in a cell

To accomodate both data scenarios you have, you will want to use this:

datevalue(text(a2,"mm/dd/yyyy"))

That will give you the date number representation for a cell that Excel has in date, or in text datatype.

SQL update statement in C#

If you don't want to use the SQL syntax (which you are forced to), then switch to a framework like Entity Framework or Linq-to-SQL where you don't write the SQL statements yourself.

Getting java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory exception

Solution is to Add common-logging.x.x jar file

Check if a string is html or not

Here's a regex-less approach I used for my own project.

If you are trying to detect HTML string among other non-HTML strings, you can convert to HTML parser object and then back and see if the string lengths are different. I.e.:

def isHTML(string):
    string1 = string[:]
    soup = BeautifulSoup(string, 'html.parser')  # Can use other HTML parser like etree
    string2 = soup.text

    if string1 != string2:
        return True
    elif string1 == string2:
        return False

It worked on my sample of 2800 strings.

Windows equivalent of OS X Keychain?

Actually, looking through MSDN, the functions they recommend using (instead of Protected Storage) are:

• CryptProtectData
• CryptUnprotectData

The link for CryptProtectData is at CryptProtectData function.

Export to xls using angularjs

One starting point could be to use this directive (ng-csv) just download the file as csv and that's something excel can understand

http://ngmodules.org/modules/ng-csv

Maybe you can adapt this code (updated link):

http://jsfiddle.net/Sourabh_/5ups6z84/2/

Altough it seems XMLSS (it warns you before opening the file, if you choose to open the file it will open correctly)

var tableToExcel = (function() {

  var uri = 'data:application/vnd.ms-excel;base64,'
, template = '<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns="http://www.w3.org/TR/REC-html40"><head><!--[if gte mso 9]><xml><x:ExcelWorkbook><x:ExcelWorksheets><x:ExcelWorksheet><x:Name>{worksheet}</x:Name><x:WorksheetOptions><x:DisplayGridlines/></x:WorksheetOptions></x:ExcelWorksheet></x:ExcelWorksheets></x:ExcelWorkbook></xml><![endif]--></head><body><table>{table}</table></body></html>'
, base64 = function(s) { return window.btoa(unescape(encodeURIComponent(s))) }
, format = function(s, c) { return s.replace(/{(\w+)}/g, function(m, p) { return c[p]; }) }

  return function(table, name) {
    if (!table.nodeType) table = document.getElementById(table)
    var ctx = {worksheet: name || 'Worksheet', table: table.innerHTML}
    window.location.href = uri + base64(format(template, ctx))
  }
})()

How can I show an element that has display: none in a CSS rule?

try setting the display to block in your javascript instead of a blank value.

How to select min and max values of a column in a datatable?

The most efficient way to do this (believe it or not) is to make two variables and write a for loop.

Error:Execution failed for task ':app:dexDebug'. com.android.ide.common.process.ProcessException

I faced same issue when converting an eclipse project to Android studio.In my case i had the design lirary jar file in eclipse project and I have added dependency of the same in gradle caused the error.I solved it by deleting jar from libs.

How to deploy a React App on Apache web server

Firstly, in your react project go to your package.json and adjust this line line of code to match your destination domain address + folder:

"homepage": "https://yourwebsite.com/your_folder_name/",

Secondly, go to terminal in your react project and type:

npm run build

Now, take all files from that newly created build folder and upload them into your_folder_name, with filezilla in subfolder like this:

public_html/your_folder_name

Check in the browser!

Ruby's File.open gives "No such file or directory - text.txt (Errno::ENOENT)" error

ENOENT means it's not there.

Just update your code to:

File.open(File.dirname(__FILE__) + '/text.txt').each {|line| puts line}

How can I use different certificates on specific connections?

We copy the JRE's truststore and add our custom certificates to that truststore, then tell the application to use the custom truststore with a system property. This way we leave the default JRE truststore alone.

The downside is that when you update the JRE you don't get its new truststore automatically merged with your custom one.

You could maybe handle this scenario by having an installer or startup routine that verifies the truststore/jdk and checks for a mismatch or automatically updates the truststore. I don't know what happens if you update the truststore while the application is running.

This solution isn't 100% elegant or foolproof but it's simple, works, and requires no code.

fatal: ambiguous argument 'origin': unknown revision or path not in the working tree

For those experiencing this error on CI/CD, adding the line below worked for me on my GitHub Actions CI/CD workflow right after running pip install pyflakes diff-cover:

git fetch origin master:refs/remotes/origin/master

This is a snippet of the solution from the diff-cover github repo:

Solution: diff-cover matches source files in the coverage XML report with source files in the git diff. For this reason, it's important that the relative paths to the files match. If you are using coverage.py to generate the coverage XML report, then make sure you run diff-cover from the same working directory.

I got the solution on the links below. It is a documented diff-cover error.

https://diff-cover.readthedocs.io/en/latest//README.html https://github.com/Bachmann1234/diff_cover/blob/master/README.rst

Hope this helps :-).

What's the Use of '\r' escape sequence?

\r move the cursor to the begin of the line.

Line breaks are managed differently on different systems. Some only use \n (line feed, e.g. Unix), some use (\r e.g. MacOS before OS X afaik) and some use \r\n (e.g. Windows afaik).

Representing Directory & File Structure in Markdown Syntax

As already recommended, you can use tree. But for using it together with restructured text some additional parameters were required.

The standard tree output will not be printed if your're using pandoc to produce pdf.

tree --dirsfirst --charset=ascii /path/to/directory will produce a nice ASCII tree that can be integrated into your document like this:

.. code::
.
|-- ContentStore
|   |-- de-DE
|   |   |-- art.mshc
|   |   |-- artnoloc.mshc
|   |   |-- clientserver.mshc
|   |   |-- noarm.mshc
|   |   |-- resources.mshc
|   |   `-- windowsclient.mshc
|   `-- en-US
|       |-- art.mshc
|       |-- artnoloc.mshc
|       |-- clientserver.mshc
|       |-- noarm.mshc
|       |-- resources.mshc
|       `-- windowsclient.mshc
`-- IndexStore
    |-- de-DE
    |   |-- art.mshi
    |   |-- artnoloc.mshi
    |   |-- clientserver.mshi
    |   |-- noarm.mshi
    |   |-- resources.mshi
    |   `-- windowsclient.mshi
    `-- en-US
        |-- art.mshi
        |-- artnoloc.mshi
        |-- clientserver.mshi
        |-- noarm.mshi
        |-- resources.mshi
        `-- windowsclient.mshi

What is the difference between 'classic' and 'integrated' pipeline mode in IIS7?

Integrated application pool mode

When an application pool is in Integrated mode, you can take advantage of the integrated request-processing architecture of IIS and ASP.NET. When a worker process in an application pool receives a request, the request passes through an ordered list of events. Each event calls the necessary native and managed modules to process portions of the request and to generate the response.

There are several benefits to running application pools in Integrated mode. First the request-processing models of IIS and ASP.NET are integrated into a unified process model. This model eliminates steps that were previously duplicated in IIS and ASP.NET, such as authentication. Additionally, Integrated mode enables the availability of managed features to all content types.

Classic application pool mode

When an application pool is in Classic mode, IIS 7.0 handles requests as in IIS 6.0 worker process isolation mode. ASP.NET requests first go through native processing steps in IIS and are then routed to Aspnet_isapi.dll for processing of managed code in the managed runtime. Finally, the request is routed back through IIS to send the response.

This separation of the IIS and ASP.NET request-processing models results in duplication of some processing steps, such as authentication and authorization. Additionally, managed code features, such as forms authentication, are only available to ASP.NET applications or applications for which you have script mapped all requests to be handled by aspnet_isapi.dll.

Be sure to test your existing applications for compatibility in Integrated mode before upgrading a production environment to IIS 7.0 and assigning applications to application pools in Integrated mode. You should only add an application to an application pool in Classic mode if the application fails to work in Integrated mode. For example, your application might rely on an authentication token passed from IIS to the managed runtime, and, due to the new architecture in IIS 7.0, the process breaks your application.

Taken from: What is the difference between DefaultAppPool and Classic .NET AppPool in IIS7?

Original source: Introduction to IIS Architecture

What causes javac to issue the "uses unchecked or unsafe operations" warning

I had 2 years old classes and some new classes. I solved it in Android Studio as follows:

allprojects {

    gradle.projectsEvaluated {
        tasks.withType(JavaCompile) {
            options.compilerArgs << "-Xlint:unchecked"
        }
    }

}

In my project build.gradle file (Borzh solution)

And then if some Metheds is left:

@SuppressWarnings("unchecked")
public void myMethod()
{
    //...
}

Run a Docker image as a container

$ docker images
REPOSITORY                TAG                 IMAGE ID            CREATED            
jamesmedice/marketplace   latest              e78c49b5f380        2 days ago          
jamesmedice/marketplace   v1.0.0              *e78c49b5f380*        2 days ago          


$ docker run -p 6001:8585 *e78c49b5f380*

Left padding a String with Zeros

Use Google Guava:

Maven:

<dependency>
     <artifactId>guava</artifactId>
     <groupId>com.google.guava</groupId>
     <version>14.0.1</version>
</dependency>

Sample code:

Strings.padStart("129018", 10, '0') returns "0000129018"  

How do I view events fired on an element in Chrome DevTools?

You can use monitorEvents function.

Just inspect your element (right mouse click ? Inspect on visible element or go to Elements tab in Chrome Developer Tools and select wanted element) then go to Console tab and write:

monitorEvents($0)

Now when you move mouse over this element, focus or click it, the name of the fired event will be displayed with its data.

To stop getting this data just write this to console:

unmonitorEvents($0)

$0 is just the last DOM element selected by Chrome Developer Tools. You can pass any other DOM object there (for example result of getElementById or querySelector).

You can also specify event "type" as second parameter to narrow monitored events to some predefined set. For example:

monitorEvents(document.body, 'mouse')

List of this available types is here.

I made a small gif that illustrates how this feature works:

Compare and contrast REST and SOAP web services?

SOAP uses WSDL for communication btw consumer and provider, whereas REST just uses XML or JSON to send and receive data

WSDL defines contract between client and service and is static by its nature. In case of REST contract is somewhat complicated and is defined by HTTP, URI, Media Formats and Application Specific Coordination Protocol. It's highly dynamic unlike WSDL.

SOAP doesn't return human readable result, whilst REST result is readable with is just plain XML or JSON

This is not true. Plain XML or JSON are not RESTful at all. None of them define any controls(i.e. links and link relations, method information, encoding information etc...) which is against REST as far as messages must be self contained and coordinate interaction between agent/client and service.

With links + semantic link relations clients should be able to determine what is next interaction step and follow these links and continue communication with service.

It is not necessary that messages be human readable, it's possible to use cryptic format and build perfectly valid REST applications. It doesn't matter whether message is human readable or not.

Thus, plain XML(application/xml) or JSON(application/json) are not sufficient formats for building REST applications. It's always reasonable to use subset of these generic media types which have strong semantic meaning and offer enough control information(links etc...) to coordinate interactions between client and server.

• For more details regarding control information I highly recommend to read this: http://www.amundsen.com/hypermedia/hfactor/
• Web Linking: http://tools.ietf.org/html/rfc5988
• Registered link relations: http://www.iana.org/assignments/link-relations/link-relations.xml

REST is over only HTTP

Not true, HTTP is most widely used and when we talk about REST web services we just assume HTTP. HTTP defines interface with it's methods(GET, POST, PUT, DELETE, PATCH etc) and various headers which can be used uniformly for interacting with resources. This uniformity can be achieved with other protocols as well.

P.S. Very simple, yet very interesting explanation of REST: http://www.looah.com/source/view/2284

sass css: target parent class from child

Git - Undo pushed commits

Here is my way:

Let's say the branch name is develop.

# Create a new temp branch based on one history commit
git checkout <last_known_good_commit_hash>
git checkout -b develop-temp

# Delete the original develop branch and 
# create a new branch with the same name based on the develop-temp branch
git branch -D develop
git checkout -b develop

# Force update this new branch
git push -f origin develop

# Remove the temp branch
git branch -D develop-temp

How do I refresh a DIV content?

To reload a section of the page, you could use jquerys load with the current url and specify the fragment you need, which would be the same element that load is called on, in this case #here:

function updateDiv()
{ 
    $( "#here" ).load(window.location.href + " #here" );
}

• Don't disregard the space within the load element selector: + " #here"

This function can be called within an interval, or attached to a click event

Sum up a column from a specific row down

=Sum(C:C)-Sum(C1:C5)

Sum everything then remove the sum of the values in the cells you don't want, no Volatile Offset's, Indirect's, or Array's needed.

Just for fun if you don't like that method you could also use:

=SUM($C$6:INDEX($C:$C,MATCH(9.99999999999999E+307,$C:$C))

The above formula will Sum only from C6 through the last cell in C:C where a match of a number is found. This is also non-volatile, but I believe more costly and sloppy. Just added it in case you'd prefer this anyways.

If you would like to do function like CountA for text using the last text value in a column you could use.

=COUNTIF(C6:INDEX($C:$C,MATCH(REPT("Z",255),$C:$C)),"T")

you could also use other combinations like:

=Sum($C$6:$C$65536) 

or

=CountIF($C$6:$C$65536,"T") 

The above would do what you ask in Excel 2003 and lower

=Sum($C$6:$C$1048576) 

or

=CountIF($C$6:$C$1048576,"T")

Would both work for Excel 2007+

All above functions would simply ignore all the blank values under the last value.

get UTC timestamp in python with datetime

Another possibility is:

d = datetime.datetime.utcnow()
epoch = datetime.datetime(1970,1,1)
t = (d - epoch).total_seconds()

This works as both "d" and "epoch" are naive datetimes, making the "-" operator valid, and returning an interval. total_seconds() turns the interval into seconds. Note that total_seconds() returns a float, even d.microsecond == 0

How to use log levels in java

Generally, you don't need all those levels, SEVERE, WARNING, INFO, FINE might be enough. We're using Log4J (not java.util.logging directly) and the following levels (which might differ in name from other logging frameworks):

• ERROR: Any error/exception that is or might be critical. Our Logger automatically sends an email for each such message on our servers (usage: logger.error("message"); )

• WARN: Any message that might warn us of potential problems, e.g. when a user tried to log in with wrong credentials - which might indicate an attack if that happens often or in short periods of time (usage: logger.warn("message"); )

• INFO: Anything that we want to know when looking at the log files, e.g. when a scheduled job started/ended (usage: logger.info("message"); )

• DEBUG: As the name says, debug messages that we only rarely turn on. (usage: logger.debug("message"); )

The beauty of this is that if you set the log level to WARN, info and debug messages have next to no performance impact. If you need to get additional information from a production system you just can lower the level to INFO or DEBUG for a short period of time (since you'd get much more log entries which make your log files bigger and harder to read). Adjusting log levels etc. can normally be done at runtime (our JBoss instance checks for changes in that config every minute or so).

Text Progress Bar in the Console

I realize I'm late to the game, but here's a slightly Yum-style (Red Hat) one I wrote (not going for 100% accuracy here, but if you're using a progress bar for that level of accuracy, then you're WRONG anyway):

import sys

def cli_progress_test(end_val, bar_length=20):
    for i in xrange(0, end_val):
        percent = float(i) / end_val
        hashes = '#' * int(round(percent * bar_length))
        spaces = ' ' * (bar_length - len(hashes))
        sys.stdout.write("\rPercent: [{0}] {1}%".format(hashes + spaces, int(round(percent * 100))))
        sys.stdout.flush()

Should produce something looking like this:

Percent: [##############      ] 69%

... where the brackets stay stationary and only the hashes increase.

This might work better as a decorator. For another day...

How do I iterate over a range of numbers defined by variables in Bash?

Replace {} with (( )):

tmpstart=0;
tmpend=4;

for (( i=$tmpstart; i<=$tmpend; i++ )) ; do 
echo $i ;
done

Yields:

0
1
2
3
4

SQL: Insert all records from one table to another table without specific the columns

You need to have at least the same number of columns and each column has to be defined in exactly the same way, i.e. a varchar column can't be inserted into an int column.

For bulk transfer, check the documentation for the SQL implementation you're using. There are often tools available to bulk transfer data from one table to another. For SqlServer 2005, for example, you could use the SQL Server Import and Export Wizard. Right-click on the database you're trying to move data around in and click Export to access it.

CRON job to run on the last day of the month

There's a slightly shorter method that can be used similar to one of the ones above. That is:

[ $(date -d +1day +%d) -eq 1 ] && echo "last day of month"

Also, the crontab entry could be update to only check on the 28th to 31st as it's pointless running it the other days of the month. Which would give you:

0 23 28-31 * * [ $(date -d +1day +%d) -eq 1 ] && myscript.sh

Split string into individual words Java

Use split()

String words[] = stringInstance.split(" ");

How to check if a variable is both null and /or undefined in JavaScript

A variable cannot be both null and undefined at the same time. However, the direct answer to your question is:

if (variable != null)

One =, not two.

There are two special clauses in the "abstract equality comparison algorithm" in the JavaScript spec devoted to the case of one operand being null and the other being undefined, and the result is true for == and false for !=. Thus if the value of the variable is undefined, it's not != null, and if it's not null, it's obviously not != null.

Now, the case of an identifier not being defined at all, either as a var or let, as a function parameter, or as a property of the global context is different. A reference to such an identifier is treated as an error at runtime. You could attempt a reference and catch the error:

var isDefined = false;
try {
  (variable);
  isDefined = true;
}
catch (x) {}

I would personally consider that a questionable practice however. For global symbols that may or may be there based on the presence or absence of some other library, or some similar situation, you can test for a window property (in browser JavaScript):

var isJqueryAvailable = window.jQuery != null;

or

var isJqueryAvailable = "jQuery" in window;

Setting environment variables in Linux using Bash

I think you're looking for export - though I could be wrong.. I've never played with tcsh before. Use the following syntax:

export VARIABLE=value

Find methods calls in Eclipse project

Select mymethod() and press ctrl+alt+h.

To see some detailed Information about any method you can use this by selecting that particular Object or method and right click. you can see the "OpenCallHierarchy" (Ctrl+Alt+H). Like that many tools are there to make your work Easier like "Quick Outline" (Ctrl+O) to view the Datatypes and methods declared in a particular .java file.

To know more about this, refer this eclipse Reference

How to generate .angular-cli.json file in Angular Cli?

If you copy paste your project the .angular-cli.json you wil not find this file try to create a new file with the same name and add the code and it wil work.

Where can I find a list of keyboard keycodes?

You don't mention what language you want to track these in, but I found two for javascript:

http://www.cambiaresearch.com/c4/702b8cd1-e5b0-42e6-83ac-25f0306e3e25/Javascript-Char-Codes-Key-Codes.aspx

Comprehensive beginner's virtualenv tutorial?

This is very good: http://simononsoftware.com/virtualenv-tutorial-part-2/

And this is a slightly more practical one: https://web.archive.org/web/20160404222648/https://iamzed.com/2009/05/07/a-primer-on-virtualenv/

"commence before first target. Stop." error

This could also caused by mismatching brace/parenthesis.

$(TARGET}:
    do_something

Just use parenthesises and you'll be fine.

Get first element from a dictionary

Though you can use First(), Dictionaries do not have order per se. Please use OrderedDictionary instead. And then you can do FirstOrDefault. This way it will be meaningful.

Error "Metadata file '...\Release\project.dll' could not be found in Visual Studio"

Re-open Visual Studio as Administrator.

I am getting "java.lang.ClassNotFoundException: com.google.gson.Gson" error even though it is defined in my classpath

you can include maven dependency like below in your pom.xml file

<!-- https://mvnrepository.com/artifact/com.google.code.gson/gson --> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.6</version> </dependency>

Error 1022 - Can't write; duplicate key in table

You are probably trying to create a foreign key in some table which exists with the same name in previously existing tables. Use the following format to name your foreign key

tablename_columnname_fk

Math.random() explanation

The Random class of Java located in the java.util package will serve your purpose better. It has some nextInt() methods that return an integer. The one taking an int argument will generate a number between 0 and that int, the latter not inclusive.

Form Submission without page refresh

<!-- index.php -->
    <!DOCTYPE html>
    <html>
    <head>
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
    </head>
    <body>
    <form id="myForm">
        <input type="text" name="fname" id="fname"/>
        <input type="submit" name="click" value="button" />
    </form>
    <script>
    $(document).ready(function(){

         $(function(){
            $("#myForm").submit(function(event){
                event.preventDefault();
                $.ajax({
                    method: 'POST',
                    url: 'submit.php',
                    dataType: "json",
                    contentType: "application/json",
                    data : $('#myForm').serialize(),
                    success: function(data){
                        alert(data);
                    },
                    error: function(xhr, desc, err){
                        console.log(err);
                    }
                });
            });
        });
    });
    </script>
    </body>
    </html>
<!-- submit.php -->
<?php
$value ="call";
header('Content-Type: application/json');
echo json_encode($value);
?>

How to display a JSON representation and not [Object Object] on the screen

<li *ngFor="let obj of myArray">{{obj | json}}</li>

How do I find the PublicKeyToken for a particular dll?

You can also check by following method.

Go to Run : type the path of DLL for which you need public key. You will find 2 files : 1. __AssemblyInfo_.ini 2. DLL file

Open this __AssemblyInfo_.ini file in notepad , here you can see Public Key Token.

Cannot access mongodb through browser - It looks like you are trying to access MongoDB over HTTP on the native driver port

MongoDB has a simple web based administrative port at 28017 by default.

There is no HTTP access at the default port of 27017 (which is what the error message is trying to suggest). The default port is used for native driver access, not HTTP traffic.

To access MongoDB, you'll need to use a driver like the MongoDB native driver for NodeJS. You won't "POST" to MongoDB directly (but you might create a RESTful API using express which uses the native drivers). Instead, you'll use a wrapper library that makes accessing MongoDB convenient. You might also consider using Mongoose (which uses the native driver) which adds an ORM-like model for MongoDB in NodeJS.

If you can't get to the web interface, it may be disabled. Normally, I wouldn't expect that you'd need it for doing development unless you're checking logs and such.

git commit error: pathspec 'commit' did not match any file(s) known to git

Had this happen to me when committing from Xcode 6, after I had added a directory of files and subdirectories to the project folder. The problem was that, in the Commit sheet, in the left sidebar, I had checkmarked not only the root directory that I had added, but all of its descendants too. To solve the problem, I checkmarked only the root directory. This also committed all of the descendants, as desired, with no error.

Removing duplicates from a String in Java

 String input = "abbcccaabbddeessacccbbddefgaabbccddeeffggadscsda";
    String output ="";

    for (int i= 0; i<input.length();i++) {
        if (!output.contains(input.substring(i, i+1))) 
            output = output+ input.substring(i, i+1);

    }


        System.out.println(output);

python: restarting a loop

Here is an example using a generator's send() method:

def restartable(seq):
    while True:
        for item in seq:
            restart = yield item
            if restart:
                break
        else:
            raise StopIteration

Example Usage:

x = [1, 2, 3, 4, 5]
total = 0
r = restartable(x)
for item in r:
    if item == 5 and total < 100:
        total += r.send(True) 
    else:
        total += item

DatabaseError: current transaction is aborted, commands ignored until end of transaction block?

In Flask shell, all I needed to do was a session.rollback() to get past this.

py2exe - generate single executable file

I've been able to create a single exe file with all resources embeded into the exe. I'm building on windows. so that will explain some of the os.system calls i'm using.

First I tried converting all my images into bitmats and then all my data files into text strings. but this caused the final exe to be very very large.

After googleing for a week i figured out how to alter py2exe script to meet my needs.

here is the patch link on sourceforge i submitted, please post comments so we can get it included in the next distribution.

http://sourceforge.net/tracker/index.php?func=detail&aid=3334760&group_id=15583&atid=315583

this explanes all the changes made, i've simply added a new option to the setup line. here is my setup.py.

i'll try to comment it as best I can. Please know that my setup.py is complex do to the fact that i'm access the images by filename. so I must store a list to keep track of them.

this is from a want-to-b screen saver I was trying to make.

I use exec to generate my setup at run time, its easyer to cut and paste like that.

exec "setup(console=[{'script': 'launcher.py', 'icon_resources': [(0, 'ICON.ico')],\
      'file_resources': [%s], 'other_resources': [(u'INDEX', 1, resource_string[:-1])]}],\
      options={'py2exe': py2exe_options},\
      zipfile = None )" % (bitmap_string[:-1])

breakdown

script = py script i want to turn to an exe

icon_resources = the icon for the exe

file_resources = files I want to embed into the exe

other_resources = a string to embed into the exe, in this case a file list.

options = py2exe options for creating everything into one exe file

bitmap_strings = a list of files to include

Please note that file_resources is not a valid option untill you edit your py2exe.py file as described in the link above.

first time i've tried to post code on this site, if I get it wrong don't flame me.

from distutils.core import setup
import py2exe #@UnusedImport
import os

#delete the old build drive
os.system("rmdir /s /q dist")

#setup my option for single file output
py2exe_options = dict( ascii=True,  # Exclude encodings
                       excludes=['_ssl',  # Exclude _ssl
                                 'pyreadline', 'difflib', 'doctest', 'locale',
                                 'optparse', 'pickle', 'calendar', 'pbd', 'unittest', 'inspect'],  # Exclude standard library
                       dll_excludes=['msvcr71.dll', 'w9xpopen.exe',
                                     'API-MS-Win-Core-LocalRegistry-L1-1-0.dll',
                                     'API-MS-Win-Core-ProcessThreads-L1-1-0.dll',
                                     'API-MS-Win-Security-Base-L1-1-0.dll',
                                     'KERNELBASE.dll',
                                     'POWRPROF.dll',
                                     ],
                       #compressed=None,  # Compress library.zip
                       bundle_files = 1,
                       optimize = 2                        
                       )

#storage for the images
bitmap_string = '' 
resource_string = ''
index = 0

print "compile image list"                          

for image_name in os.listdir('images/'):
    if image_name.endswith('.jpg'):
        bitmap_string += "( " + str(index+1) + "," + "'" + 'images/' + image_name + "'),"
        resource_string += image_name + " "
        index += 1

print "Starting build\n"

exec "setup(console=[{'script': 'launcher.py', 'icon_resources': [(0, 'ICON.ico')],\
      'file_resources': [%s], 'other_resources': [(u'INDEX', 1, resource_string[:-1])]}],\
      options={'py2exe': py2exe_options},\
      zipfile = None )" % (bitmap_string[:-1])

print "Removing Trash"
os.system("rmdir /s /q build")
os.system("del /q *.pyc")
print "Build Complete"

ok, thats it for the setup.py now the magic needed access the images. I developed this app without py2exe in mind then added it later. so you'll see access for both situations. if the image folder can't be found it tries to pull the images from the exe resources. the code will explain it. this is part of my sprite class and it uses a directx. but you can use any api you want or just access the raw data. doesn't matter.

def init(self):
    frame = self.env.frame
    use_resource_builtin = True
    if os.path.isdir(SPRITES_FOLDER):
        use_resource_builtin = False
    else:
        image_list = LoadResource(0, u'INDEX', 1).split(' ')

    for (model, file) in SPRITES.items():
        texture = POINTER(IDirect3DTexture9)()
        if use_resource_builtin: 
            data = LoadResource(0, win32con.RT_RCDATA, image_list.index(file)+1) #windll.kernel32.FindResourceW(hmod,typersc,idrsc)               
            d3dxdll.D3DXCreateTextureFromFileInMemory(frame.device,   #Pointer to an IDirect3DDevice9 interface
                                              data,                #Pointer to the file in memory
                                              len(data),           #Size of the file in memory
                                              byref(texture))      #ppTexture
        else:
            d3dxdll.D3DXCreateTextureFromFileA(frame.device, #@UndefinedVariable
                                               SPRITES_FOLDER + file,
                                               byref(texture))            
        self.model_sprites[model] = texture
    #else:
    #    raise Exception("'sprites' folder is not present!")

Any questions fell free to ask.

How to output (to a log) a multi-level array in a format that is human-readable?

Syntax

print_r(variable, return);

variable Required. Specifies the variable to return information about

return Optional. When set to true, this function will return the information (not print it). Default is false

Example

error_log( print_r(<array Variable>, TRUE) );

Uploading Laravel Project onto Web Server

I believe - your Laravel files/folders should not be placed in root directory.

e.g. If your domain is pointed to public_html directory then all content should placed in that directory. How ? let me tell you

1. Copy all files and folders ( including public folder ) in public html
2. Copy all content of public folder and paste it in document root ( i.e. public_html )
3. Remove the public folder

4. Open your bootstrap/paths.php and then changed 'public' => __DIR__.'/../public', into 'public' => __DIR__.'/..',

5. and finally in index.php,

   Change

require __DIR__.'/../bootstrap/autoload.php';

$app = require_once __DIR__.'/../bootstrap/start.php';

into

require __DIR__.'/bootstrap/autoload.php';

$app = require_once __DIR__.'/bootstrap/start.php';

Your Laravel application should work now.

How to enumerate an enum

Just by combining the top answers, I threw together a very simple extension:

public static class EnumExtensions
{
    /// <summary>
    /// Gets all items for an enum value.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="value">The value.</param>
    /// <returns></returns>
    public static IEnumerable<T> GetAllItems<T>(this T value) where T : Enum
    {
        return (T[])Enum.GetValues(typeof (T));
    }
}

It is clean, simple, and, by @Jeppe-Stig-Nielsen's comment, fast.

WCF service startup error "This collection already contains an address with scheme http"

I came by the same error on an old 2010 Exchange Server. A service(Exchange mailbox replication service) was giving out the above error and the migration process could not be continued. Searching through the internet, i came by this link which stated the below:

The Exchange GRE fails to open when installed for the first time or if any changes are made to the IIS server. It fails with snap-in error and when you try to open the snap-in page, the following content is displayed:

This collection already contains an address with scheme http.  There can be at most one address per scheme in this collection. If your service is being hosted in IIS you can fix the problem by setting 'system.serviceModel/serviceHostingEnvironment/multipleSiteBindingsEnabled' to true or specifying 'system.serviceModel/serviceHostingEnvironment/baseAddressPrefixFilters'."

Cause: This error occurs because http port number 443 is already in use by another application and the IIS server is not configured to handle multiple binding to the same port.

Solution: Configure IIS server to handle multiple port bindings. Contact the vendor (Microsoft) to configure it.

Since these services were offered from an IIS Web Server, checking the Bindings on the Root Site fixed the problem. Someone had messed up the Site Bindings, defining rules that were overlapping themselves and messed up the services.

Fixing the correct Bindings resolved the problem, in my case, and i did not have to configure the Web.Config.

How to change Rails 3 server default port in develoment?

Combining two previous answers, for Rails 4.0.4 (and up, presumably), this suffices at the end of config/boot.rb:

require 'rails/commands/server'

module Rails
  class Server
    def default_options
      super.merge({Port: 10524})
    end
  end
end

How do I load an url in iframe with Jquery

$("#frame").click(function () { 
    this.src="http://www.google.com/";
});

Sometimes plain JavaScript is even cooler and faster than jQuery ;-)

Error including image in Latex

On a Mac (pdftex) I managed to include a png file simply with \includegraphics[width=1.2\textwidth]{filename.png}. But in order for that to work I had to comment out the following 2 packages:

%\usepackage[dvips]{epsfig}

%\usepackage[dvips]{graphicx}

...and simply use package graphicx:

\usepackage{graphicx}

It seems [dvips] is problematic when used with pdftex.

Check if a variable is of function type

An other simply way:

var fn = function () {}
if (fn.constructor === Function) {
  // true
} else {
  // false
}

Retina displays, high-res background images

Do I need to double the size of the .box div to 400px by 400px to match the new high res background image

No, but you do need to set the background-size property to match the original dimensions:

@media (-webkit-min-device-pixel-ratio: 2), 
(min-resolution: 192dpi) { 

    .box{
        background:url('images/[email protected]') no-repeat top left;
        background-size: 200px 200px;
    }
}

---

EDIT

To add a little more to this answer, here is the retina detection query I tend to use:

@media
only screen and (-webkit-min-device-pixel-ratio: 2),
only screen and (   min--moz-device-pixel-ratio: 2),
only screen and (     -o-min-device-pixel-ratio: 2/1),
only screen and (        min-device-pixel-ratio: 2),
only screen and (                min-resolution: 192dpi),
only screen and (                min-resolution: 2dppx) { 

}

- Source

NB. This min--moz-device-pixel-ratio: is not a typo. It is a well documented bug in certain versions of Firefox and should be written like this in order to support older versions (prior to Firefox 16). - Source

---

As @LiamNewmarch mentioned in the comments below, you can include the background-size in your shorthand background declaration like so:

.box{
    background:url('images/[email protected]') no-repeat top left / 200px 200px;
}

However, I personally would not advise using the shorthand form as it is not supported in iOS <= 6 or Android making it unreliable in most situations.

How do you change the formatting options in Visual Studio Code?

If we are talking Visual Studio Code nowadays you set a default formatter in your settings.json:

  // Defines a default formatter which takes precedence over all other formatter settings. 
  // Must be the identifier of an extension contributing a formatter.
  "editor.defaultFormatter": null,

Point to the identifier of any installed extension, i.e.

"editor.defaultFormatter": "esbenp.prettier-vscode"

You can also do so format-specific:

"[html]": {
    "editor.defaultFormatter": "esbenp.prettier-vscode"
},
"[scss]": {
    "editor.defaultFormatter": "esbenp.prettier-vscode"
},
"[sass]": {
    "editor.defaultFormatter": "michelemelluso.code-beautifier"
},

Also see here.

---

You could also assign other keys for different formatters in your keyboard shortcuts (keybindings.json). By default, it reads:

{
  "key": "shift+alt+f",
  "command": "editor.action.formatDocument",
  "when": "editorHasDocumentFormattingProvider && editorHasDocumentFormattingProvider && editorTextFocus && !editorReadonly"
}

---

Lastly, if you decide to use the Prettier plugin and prettier.rc, and you want for example different indentation for html, scss, json...

{
    "semi": true,
    "singleQuote": false,
    "trailingComma": "none",
    "useTabs": false,

    "overrides": [
        {
            "files": "*.component.html",
            "options": {
                "parser": "angular",
                "tabWidth": 4
            }
        },
        {
            "files": "*.scss",
            "options": {
                "parser": "scss",
                "tabWidth": 2
            }
        },
        {
            "files": ["*.json", ".prettierrc"],
            "options": {
                "parser": "json",
                "tabWidth": 4
            }
        }
    ]
}

Importing a GitHub project into Eclipse

It can be done in two ways:

1.Use clone Git

2.You can set it up manually by rearranging folders given in it. make a two separate folder 'src' and 'res' and place appropriate classes and xml file given by library. and then import project from eclipse and make it as library, that's it.

How to import an Excel file into SQL Server?

There are many articles about writing code to import an excel file, but this is a manual/shortcut version:

If you don't need to import your Excel file programmatically using code you can do it very quickly using the menu in SQL Management Studio.

The quickest way to get your Excel file into SQL is by using the import wizard:

1. Open SSMS (Sql Server Management Studio) and connect to the database where you want to import your file into.
2. Import Data: in SSMS in Object Explorer under 'Databases' right-click the destination database, select Tasks, Import Data. An import wizard will pop up (you can usually just click 'Next' on the first screen).

3. The next window is 'Choose a Data Source', select Excel:

   • In the 'Data Source' dropdown list select Microsoft Excel (this option should appear automatically if you have excel installed).

   • Click the 'Browse' button to select the path to the Excel file you want to import.

   • Select the version of the excel file (97-2003 is usually fine for files with a .XLS extension, or use 2007 for newer files with a .XLSX extension)
   • Tick the 'First Row has headers' checkbox if your excel file contains headers.
   • Click next.

4. On the 'Choose a Destination' screen, select destination database:
   • Select the 'Server name', Authentication (typically your sql username & password) and select a Database as destination. Click Next.

5. On the 'Specify Table Copy or Query' window:

   • For simplicity just select 'Copy data from one or more tables or views', click Next.

6. 'Select Source Tables:' choose the worksheet(s) from your Excel file and specify a destination table for each worksheet. If you don't have a table yet the wizard will very kindly create a new table that matches all the columns from your spreadsheet. Click Next.

7. Click Finish.

How can I convert a .jar to an .exe?

JSmooth .exe wrapper

JSmooth is a Java Executable Wrapper. It creates native Windows launchers (standard .exe) for your Java applications. It makes java deployment much smoother and user-friendly, as it is able to find any installed Java VM by itself. When no VM is available, the wrapper can automatically download and install a suitable JVM, or simply display a message or redirect the user to a website.

JSmooth provides a variety of wrappers for your java application, each of them having their own behavior: Choose your flavor!

Download: http://jsmooth.sourceforge.net/

JarToExe 1.8 Jar2Exe is a tool to convert jar files into exe files. Following are the main features as describe on their website:

Can generate “Console”, “Windows GUI”, “Windows Service” three types of .exe files.

Generated .exe files can add program icons and version information. Generated .exe files can encrypt and protect java programs, no temporary files will be generated when the program runs.

Generated .exe files provide system tray icon support. Generated .exe files provide record system event log support. Generated windows service .exe files are able to install/uninstall itself, and support service pause/continue.

• New release of x64 version, can create 64 bits executives. (May 18, 2008)
• Both wizard mode and command line mode supported. (May 18, 2008)
• Download: http://www.brothersoft.com/jartoexe-75019.html

Executor

Package your Java application as a jar, and Executor will turn the jar into a Windows .exe file, indistinguishable from a native application. Simply double-clicking the .exe file will invoke the Java Runtime Environment and launch your application.

How do I concatenate text in a query in sql server?

You might want to consider NULL values as well. In your example, if the column notes has a null value, then the resulting value will be NULL. If you want the null values to behave as empty strings (so that the answer comes out 'SomeText'), then use the IsNull function:

Select IsNull(Cast(notes as nvarchar(4000)),'') + 'SomeText' From NotesTable a

how to automatically scroll down a html page?

Use document.scrollTop to change the position of the document. Set the scrollTop of the document equal to the bottom of the featured section of your site

Textarea Auto height

var minRows = 5;
var maxRows = 26;
function ResizeTextarea(id) {
    var t = document.getElementById(id);
    if (t.scrollTop == 0)   t.scrollTop=1;
    while (t.scrollTop == 0) {
        if (t.rows > minRows)
                t.rows--; else
            break;
        t.scrollTop = 1;
        if (t.rows < maxRows)
                t.style.overflowY = "hidden";
        if (t.scrollTop > 0) {
            t.rows++;
            break;
        }
    }
    while(t.scrollTop > 0) {
        if (t.rows < maxRows) {
            t.rows++;
            if (t.scrollTop == 0) t.scrollTop=1;
        } else {
            t.style.overflowY = "auto";
            break;
        }
    }
}

Grab a segment of an array in Java without creating a new array on heap

One option would be to pass the whole array and the start and end indices, and iterate between those instead of iterating over the whole array passed.

void method1(byte[] array) {
    method2(array,4,5);
}
void method2(byte[] smallarray,int start,int end) {
    for ( int i = start; i <= end; i++ ) {
        ....
    }
}

How to access command line arguments of the caller inside a function?

#!/usr/bin/env bash

echo name of script is $0
echo first argument is $1
echo second argument is $2
echo seventeenth argument is $17
echo number of arguments is $#

Edit: please see my comment on question

jQuery UI Sortable, then write order into a database

Thought this might help as well. A) it was designed to keep payload to its minimum while sending back to server, after each sort. (instead of sending all elements each time or iterating through many elements that server might chuck out) B) I needed to send back custom id without compromising the id / name of the element. This code will get the list from asp.net server and then upon sorting only 2 values will be sent back: The db id of sorted element and db id of the element next to which it was dropped. Based on those 2 values, server can easily identify the new postion.

<div id="planlist" style="width:1000px">
    <ul style="width:1000px">
       <li plid="listId1"><a href="#pl-1">List 1</a></li>
       <li plid="listId2"><a href="#pl-2">List 1</a></li>
       <li plid="listId3"><a href="#pl-3">List 1</a></li>
       <li plid="listId4"><a href="#pl-4">List 1</a></li>
    </ul>
    <div id="pl-1"></div>
    <div id="pl-2"></div>
    <div id="pl-3"></div>
    <div id="pl-4"></div>
</div>
<script type="text/javascript" language="javascript">
    $(function () {
        var tabs = $("#planlist").tabs();
        tabs.find(".ui-tabs-nav").sortable({
            axis: "x",
            stop: function () {
                tabs.tabs("refresh");
            },
            update: function (event, ui) {
                //db id of the item sorted
                alert(ui.item.attr('plid'));
                //db id of the item next to which the dragged item was dropped
                alert(ui.item.prev().attr('plid'));

                //make ajax call
            }
        });
    });
</script>

Concatenate String in String Objective-c

You would normally use -stringWithFormat here.

NSString *myString = [NSString stringWithFormat:@"%@%@%@", @"some text", stringVariable, @"some more text"];

Scripting Language vs Programming Language

Programming Language : Is compiled to machine code and run on the hardware of the underlying Operating System.

Scripting Language : Is unstructure subset of programming language. It is generally interpreted. it basically "scripts" other things to do stuff. The primary focus isn't primarily building your own apps but getting an existing app to act the way you want, e.g. JavaScript for browsers, TCL etc.,

*** But there are situation where a programming language is converted to interpreter and vice-verse like use have a C interpreter where you can 'C' Script. Scripts are generally written to control an application behaviour where as Programming Language is use to build applications. But beware that the demarcation is blurring day - by - day as an example of Python it depends on how one uses the language.

Android 8: Cleartext HTTP traffic not permitted

Oneliner to solve your problem. I assume you will store your URL in myURL string. Add this line and you are done. myURL = myURL.replace("http", "https");

CSS opacity only to background color, not the text on it?

I had the same problem. I want a 100% transparent background color. Just use this code; it's worked great for me:

rgba(54, 25, 25, .00004);

You can see examples on the left side on this web page (the contact form area).

Selecting specific rows and columns from NumPy array

USE:

 >>> a[[0,1,3]][:,[0,2]]
array([[ 0,  2],
   [ 4,  6],
   [12, 14]])

OR:

>>> a[[0,1,3],::2]
array([[ 0,  2],
   [ 4,  6],
   [12, 14]])

Could not find or load main class org.gradle.wrapper.GradleWrapperMain

In my case, I left out wrapper sub folder while copying gradle folder and got the same error.

Could not find or load main class org.gradle.wrapper.GradleWrapperMain

make sure you have the correct folder structure if you copy wrapper from other location.

+-- build.gradle
+-- gradle
¦   +-- wrapper
¦       +-- gradle-wrapper.jar
¦       +-- gradle-wrapper.properties
+-- gradlew
+-- gradlew.bat
+-- settings.gradle

Passing a varchar full of comma delimited values to a SQL Server IN function

Best and simple approach.

DECLARE @AccumulateKeywordCopy NVARCHAR(2000),@IDDupCopy NVARCHAR(50);
SET @AccumulateKeywordCopy ='';
SET @IDDupCopy ='';
SET @IDDup = (SELECT CONVERT(VARCHAR(MAX), <columnName>) FROM <tableName> WHERE <clause>)

SET @AccumulateKeywordCopy = ','+@AccumulateKeyword+',';
SET @IDDupCopy = ','+@IDDup +',';
SET @IDDupCheck = CHARINDEX(@IDDupCopy,@AccumulateKeywordCopy)

How to get first character of a string in SQL?

I prefer:

SUBSTRING (my_column, 1, 1)

because it is Standard SQL-92 syntax and therefore more portable.

---

Strictly speaking, the standard version would be

SUBSTRING (my_column FROM 1 FOR 1)

The point is, transforming from one to the other, hence to any similar vendor variation, is trivial.

p.s. It was only recently pointed out to me that functions in standard SQL are deliberately contrary, by having parameters lists that are not the conventional commalists, in order to make them easily identifiable as being from the standard!

How to import a Python class that is in a directory above?

import sys
sys.path.append("..") # Adds higher directory to python modules path.

Use chrome as browser in C#?

OpenWebKitSharp gives you full control over WebKit Nightly, which is very close to webkit in terms of performance and compatibility. Chrome uses WebKit Chromium engine, while WebKit.NET uses Cairo and OpenWebKitSharp Nightly. Chromium should be the best of these builds, while at 2nd place should come Nightly and that's why I suggest OpenWebKitSharp.

http://gt-web-software.webs.com/libraries.htm at the OpenWebKitSharp section

Parse json string to find and element (key / value)

You want to convert it to an object first and then access normally making sure to cast it.

JObject obj = JObject.Parse(json);
string name = (string) obj["Name"];

Why is `input` in Python 3 throwing NameError: name... is not defined

temperature = input("What's the current temperature in your city? (please use the format ??C or ???F) >>> ")

### warning... the result from input will <str> on Python 3.x only
### in the case of Python 2.x, the result from input is the variable type <int>
### for the <str> type as the result for Python 2.x it's neccessary to use the another: raw_input()

temp_int = int(temperature[:-1])     # 25 <int> (as example)
temp_str = temperature[-1:]          # "C" <str> (as example)

if temp_str.lower() == 'c':
    print("Your temperature in Fahrenheit is: {}".format(  (9/5 * temp_int) + 32      )  )
elif temp_str.lower() == 'f':
    print("Your temperature in Celsius is: {}".format(     ((5/9) * (temp_int - 32))  )  )

Current time in microseconds in java

If you intend to use it for realtime system, perhaps java isnt the best choice to get the timestamp. But if youre going to use if for unique key, then Jason Smith's answer will do enough. But just in case, to anticipate 2 item end up getting the same timestamp (its possible if those 2 were processed almost simultaneously), you can loop until the last timestamp not equals with the current timestamp.

String timestamp = new String();
do {
    timestamp = String.valueOf(MicroTimestamp.INSTANCE.get());
    item.setTimestamp(timestamp);
} while(lasttimestamp.equals(timestamp));
lasttimestamp = item.getTimestamp();

Is it possible to make a Tree View with Angular?

So many great solutions, but I feel they all in one way or another over-complicate things a bit.

I wanted to create something that recreated the simplicity of @Mark Lagendijk's awnser, but without it defining a template in the directive, but rather would let the "user" create the template in HTML...

With ideas taken from https://github.com/stackfull/angular-tree-repeat etc... I ended up with creating the project: https://github.com/dotJEM/angular-tree

Which allows you to build your tree like:

<ul dx-start-with="rootNode">
  <li ng-repeat="node in $dxPrior.nodes">
    {{ node.name }}
    <ul dx-connect="node"/>
  </li>
</ul>

Which to me is cleaner than having to create multiple directives for differently structured trees.... In essence calling the above a tree is a bit false, it picks much more off from @ganaraj's awnser of "recursive templates", but allows us to define the template where we need the tree.

(you could do that with a script tag based template, but it still has to sit right outside the actual tree node, and it still just feels a bit yuk...)

Left here for just another choice...

how to check if a form is valid programmatically using jQuery Validation Plugin

For Magento, you check validation of form by something like below.

You can try this:

require(["jquery"], function ($) {
    $(document).ready(function () {
        $('#my-button-name').click(function () { // The button type should be "button" and not submit
            if ($('#form-name').valid()) {
                alert("Validation pass");
                return false;
            }else{
                alert("Validation failed");
                return false;
            }
        });
    });
});

Hope this may help you!

How to get name of the computer in VBA?

A shell method to read the environmental variable for this courtesy of devhut

Debug.Print CreateObject("WScript.Shell").ExpandEnvironmentStrings("%COMPUTERNAME%")

---

Same source gives an API method:

Option Explicit

#If VBA7 And Win64 Then
    'x64 Declarations
    Declare PtrSafe Function GetComputerName Lib "kernel32" Alias "GetComputerNameA" (ByVal lpBuffer As String, nSize As Long) As Long
#Else
    'x32 Declaration
    Declare Function GetComputerName Lib "kernel32" Alias "GetComputerNameA" (ByVal lpBuffer As String, nSize As Long) As Long
#End If

Public Sub test()

    Debug.Print ComputerName
    
End Sub

Public Function ComputerName() As String
    Dim sBuff                 As String * 255
    Dim lBuffLen              As Long
    Dim lResult               As Long
 
    lBuffLen = 255
    lResult = GetComputerName(sBuff, lBuffLen)
    If lBuffLen > 0 Then
        ComputerName = Left(sBuff, lBuffLen)
    End If
End Function

Can a background image be larger than the div itself?

Not really - the background image is bounded by the element it's applied to, and the overflow properties only apply to the content (i.e. markup) within an element.

You can add another div into your footer div and apply the background image to that, though, and have that overflow instead.

lists and arrays in VBA

You will have to change some of your data types but the basics of what you just posted could be converted to something similar to this given the data types I used may not be accurate.

Dim DateToday As String: DateToday = Format(Date, "yyyy/MM/dd")
Dim Computers As New Collection
Dim disabledList As New Collection
Dim compArray(1 To 1) As String

'Assign data to first item in array
compArray(1) = "asdf"

'Format = Item, Key
Computers.Add "ErrorState", "Computer Name"

'Prints "ErrorState"
Debug.Print Computers("Computer Name")

Collections cannot be sorted so if you need to sort data you will probably want to use an array.

Here is a link to the outlook developer reference. http://msdn.microsoft.com/en-us/library/office/ff866465%28v=office.14%29.aspx

Another great site to help you get started is http://www.cpearson.com/Excel/Topic.aspx

Moving everything over to VBA from VB.Net is not going to be simple since not all the data types are the same and you do not have the .Net framework. If you get stuck just post the code you're stuck converting and you will surely get some help!

Edit:

Sub ArrayExample()
    Dim subject As String
    Dim TestArray() As String
    Dim counter As Long

    subject = "Example"
    counter = Len(subject)

    ReDim TestArray(1 To counter) As String

    For counter = 1 To Len(subject)
        TestArray(counter) = Right(Left(subject, counter), 1)
    Next
End Sub

Iframe positioning

you have to use this css property,

 position:relative;

use it for your #contentframe div tag

#1273 – Unknown collation: ‘utf8mb4_unicode_520_ci’

find and replace:

utf8mb4_unicode_520_ci

with

utf8_general_ci

in whole sql file

ORA-30926: unable to get a stable set of rows in the source tables

Had the error today on a 12c and none of the existing answers fit (no duplicates, no non-deterministic expressions in the WHERE clause). My case was related to that other possible cause of the error, according to Oracle's message text (emphasis below):

ORA-30926: unable to get a stable set of rows in the source tables
Cause: A stable set of rows could not be got because of large dml activity or a non-deterministic where clause.

The merge was part of a larger batch, and was executed on a live database with many concurrent users. There was no need to change the statement. I just committed the transaction before the merge, then ran the merge separately, and committed again. So the solution was found in the suggested action of the message:

Action: Remove any non-deterministic where clauses and reissue the dml.

Curl GET request with json parameter

GET takes name value pairs.

Try something like:

curl http://server:5050/a/c/getName/?param1=pradeep

or

curl http://server:5050/a/c/getName?param1=pradeep

btw a regular REST should look something like

curl http://server:5050/a/c/getName/pradeep If it takes JSON in GET URL, it's not a standard way.

function is not defined error in Python

if working with IDLE installed version of Python

>>>def any(a,b):
...    print(a+b)
...
>>>any(1,2)
3

How to get the height of a body element

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

Plotting of 1-dimensional Gaussian distribution function

In addition to previous answers, I recommend to first calculate the ratio in the exponent, then taking the square:

def gaussian(x,x0,sigma):
  return np.exp(-np.power((x - x0)/sigma, 2.)/2.)

That way, you can also calculate the gaussian of very small or very large numbers:

In: gaussian(1e-12,5e-12,3e-12)
Out: 0.64118038842995462

How to properly use the "choices" field option in Django

$ pip install django-better-choices

For those who are interested, I have created django-better-choices library, that provides a nice interface to work with Django choices for Python 3.7+. It supports custom parameters, lots of useful features and is very IDE friendly.

You can define your choices as a class:

from django_better_choices import Choices


class PAGE_STATUS(Choices):
    CREATED = 'Created'
    PENDING = Choices.Value('Pending', help_text='This set status to pending')
    ON_HOLD = Choices.Value('On Hold', value='custom_on_hold')

    VALID = Choices.Subset('CREATED', 'ON_HOLD')

    class INTERNAL_STATUS(Choices):
        REVIEW = 'On Review'

    @classmethod
    def get_help_text(cls):
        return tuple(
            value.help_text
            for value in cls.values()
            if hasattr(value, 'help_text')
        )

Then do the following operations and much much more:

print( PAGE_STATUS.CREATED )                # 'created'
print( PAGE_STATUS.ON_HOLD )                # 'custom_on_hold'
print( PAGE_STATUS.PENDING.display )        # 'Pending'
print( PAGE_STATUS.PENDING.help_text )      # 'This set status to pending'

'custom_on_hold' in PAGE_STATUS.VALID       # True
PAGE_STATUS.CREATED in PAGE_STATUS.VALID    # True

PAGE_STATUS.extract('CREATED', 'ON_HOLD')   # ~= PAGE_STATUS.VALID

for value, display in PAGE_STATUS:
    print( value, display )

PAGE_STATUS.get_help_text()
PAGE_STATUS.VALID.get_help_text()

And of course, it is fully supported by Django and Django Migrations:

class Page(models.Model):
    status = models.CharField(choices=PAGE_STATUS, default=PAGE_STATUS.CREATED)

Full documentation here: https://pypi.org/project/django-better-choices/

JavaFX Application Icon

stage.getIcons().add(new Image("/images/logo_only.png"));

It is good habit to make images folder in your src folder and get images from it.

Subprocess check_output returned non-zero exit status 1

The word check_ in the name means that if the command (the shell in this case that returns the exit status of the last command (yum in this case)) returns non-zero status then it raises CalledProcessError exception. It is by design. If the command that you want to run may return non-zero status on success then either catch this exception or don't use check_ methods. You could use subprocess.call in your case because you are ignoring the captured output, e.g.:

import subprocess

rc = subprocess.call(['grep', 'pattern', 'file'],
                     stdout=subprocess.DEVNULL, stderr=subprocess.STDOUT)
if rc == 0: # found
   ...
elif rc == 1: # not found
   ...
elif rc > 1: # error
   ...

You don't need shell=True to run the commands from your question.

Is there an equivalent to e.PageX position for 'touchstart' event as there is for click event?

Kinda late, but you need to access the original event, not the jQuery massaged one. Also, since these are multi-touch events, other changes need to be made:

$('#box').live('touchstart', function(e) {
  var xPos = e.originalEvent.touches[0].pageX;
});

If you want other fingers, you can find them in other indices of the touches list.

UPDATE FOR NEWER JQUERY:

$(document).on('touchstart', '#box', function(e) {
  var xPos = e.originalEvent.touches[0].pageX;
});

Why do I get "MismatchSenderId" from GCM server side?

Check google-services.json file in app folder of your Android project. Generate a new one from Firebase console if you are unsure. I got this error in two cases.

1. I used a test Firebase project with test application (that contained right google-services.json file). Then I tried to send push notification to another application and got this error ('"error": "MismatchSenderId"'). I understood that the second application was bound to another Firebase project with different google-services.json. Because server keys are different, the request should be rewritten.

2. I changed google-services.json in the application, because I wanted to replace test Firebase project with an actual. I generated right google-services.json file, changed request, but kept receiving this error. On the next day it fixed itself. I suspect Firebase doesn't update synchronously.

To get a server key for the request, open https://console.firebase.google.com and select an appropriate project.

Then paste it in the request.

How can I throw a general exception in Java?

You could create your own Exception class:

public class InvalidSpeedException extends Exception {

  public InvalidSpeedException(String message){
     super(message);
  }

}

In your code:

throw new InvalidSpeedException("TOO HIGH");

Rename file with Git

As far as I can tell, GitHub does not provide shell access, so I'm curious about how you managed to log in in the first place.

$ ssh -T [email protected]
Hi username! You've successfully authenticated, but GitHub does not provide
shell access.

You have to clone your repository locally, make the change there, and push the change to GitHub.

$ git clone [email protected]:username/reponame.git
$ cd reponame
$ git mv README README.md
$ git commit -m "renamed"
$ git push origin master

Verilog generate/genvar in an always block

You don't need a generate bock if you want all the bits of temp assigned in the same always block.

parameter ROWBITS = 4;
reg [ROWBITS-1:0] temp;
always @(posedge sysclk) begin
    for (integer c=0; c<ROWBITS; c=c+1) begin: test
        temp[c] <= 1'b0;
    end
end

Alternatively, if your simulator supports IEEE 1800 (SytemVerilog), then

parameter ROWBITS = 4;
reg [ROWBITS-1:0] temp;
always @(posedge sysclk) begin
        temp <= '0; // fill with 0
    end
end

How do you access the matched groups in a JavaScript regular expression?

/*Regex function for extracting object from "window.location.search" string.
 */

var search = "?a=3&b=4&c=7"; // Example search string

var getSearchObj = function (searchString) {

    var match, key, value, obj = {};
    var pattern = /(\w+)=(\w+)/g;
    var search = searchString.substr(1); // Remove '?'

    while (match = pattern.exec(search)) {
        obj[match[0].split('=')[0]] = match[0].split('=')[1];
    }

    return obj;

};

console.log(getSearchObj(search));

How to open google chrome from terminal?

If you just want to open the Google Chrome from terminal instantly for once then open -a "Google Chrome" works fine from Mac Terminal.

If you want to use an alias to call Chrome from terminal then you need to edit the bash profile and add an alias on ~/.bash_profile or ~/.zshrc file.The steps are below :

• Edit ~/.bash_profile or ~/.zshrc file and add the following line alias chrome="open -a 'Google Chrome'"
• Save and close the file.
• Logout and relaunch Terminal
• Type chrome filename for opening a local file.
• Type chrome url for opening url.

How to replace list item in best way

Use FindIndex and lambda to find and replace your values:

int j = listofelements.FindIndex(i => i.Contains(valueFieldValue.ToString())); //Finds the item index

lstString[j] = lstString[j].Replace(valueFieldValue.ToString(), value.ToString()); //Replaces the item by new value

NPM doesn't install module dependencies

happens with old node version. use latest version of node like this:

$ nvm use 8.0
$ rm -rf node_modules
$ npm install
$ npm i somemodule

edit: also make sure you save.
eg: npm install yourmoduleName --save

Assigning variables with dynamic names in Java

This is not how you do things in Java. There are no dynamic variables in Java. Java variables have to be declared in the source code¹.

Depending on what you are trying to achieve, you should use an array, a List or a Map; e.g.

int n[] = new int[3];
for (int i = 0; i < 3; i++) {
    n[i] = 5;
}

List<Integer> n = new ArrayList<Integer>();
for (int i = 1; i < 4; i++) {
    n.add(5);
}

Map<String, Integer> n = new HashMap<String, Integer>();
for (int i = 1; i < 4; i++) {
    n.put("n" + i, 5);
}

---

It is possible to use reflection to dynamically refer to variables that have been declared in the source code. However, this only works for variables that are class members (i.e. static and instance fields). It doesn't work for local variables. See @fyr's "quick and dirty" example.

However doing this kind of thing unnecessarily in Java is a bad idea. It is inefficient, the code is more complicated, and since you are relying on runtime checking it is more fragile. And this is not "variables with dynamic names". It is better described as dynamic access to variables with static names.

---

^{1 - That statement is slightly inaccurate. If you use BCEL or ASM, you can "declare" the variables in the bytecode file. But don't do it! That way lies madness!}

How to watch for form changes in Angular

To complete a bit more previous great answers, you need to be aware that forms leverage observables to detect and handle value changes. It's something really important and powerful. Both Mark and dfsq described this aspect in their answers.

Observables allow not only to use the subscribe method (something similar to the then method of promises in Angular 1). You can go further if needed to implement some processing chains for updated data in forms.

I mean you can specify at this level the debounce time with the debounceTime method. This allows you to wait for an amount of time before handling the change and correctly handle several inputs:

this.form.valueChanges
    .debounceTime(500)
    .subscribe(data => console.log('form changes', data));

You can also directly plug the processing you want to trigger (some asynchronous one for example) when values are updated. For example, if you want to handle a text value to filter a list based on an AJAX request, you can leverage the switchMap method:

this.textValue.valueChanges
    .debounceTime(500)
    .switchMap(data => this.httpService.getListValues(data))
    .subscribe(data => console.log('new list values', data));

You even go further by linking the returned observable directly to a property of your component:

this.list = this.textValue.valueChanges
    .debounceTime(500)
    .switchMap(data => this.httpService.getListValues(data))
    .subscribe(data => console.log('new list values', data));

and display it using the async pipe:

<ul>
  <li *ngFor="#elt of (list | async)">{{elt.name}}</li>
</ul>

Just to say that you need to think the way to handle forms differently in Angular2 (a much more powerful way ;-)).

Hope it helps you, Thierry

How to assign name for a screen?

As already stated, screen -S SESSIONTITLE works for starting a session with a title (SESSIONTITLE), but if you start a session and later decide to change its title. This can be accomplished by using the default key bindings:

Ctrl+a, A

Which prompts:

Set windows title to:SESSIONTITLE

Change SESSIONTITLE by backspacing and typing in the desired title. To confirm the name change and list all titles.

Ctrl+a, "

In Angular, how do you determine the active route?

Below is the method using RouteData to style menuBar items depending of the current route:

RouteConfig includes data with tab (current route):

@RouteConfig([
  {
    path: '/home',    name: 'Home',    component: HomeComponent,
    data: {activeTab: 'home'},  useAsDefault: true
  }, {
    path: '/jobs',    name: 'Jobs',    data: {activeTab: 'jobs'},
    component: JobsComponent
  }
])

A piece of layout:

  <li role="presentation" [ngClass]="{active: isActive('home')}">
    <a [routerLink]="['Home']">Home</a>
  </li>
  <li role="presentation" [ngClass]="{active: isActive('jobs')}">
    <a [routerLink]="['Jobs']">Jobs</a>
  </li>

Class:

export class MainMenuComponent {
  router: Router;

  constructor(data: Router) {
    this.router = data;
  }

  isActive(tab): boolean {
    if (this.router.currentInstruction && this.router.currentInstruction.component.routeData) {
      return tab == this.router.currentInstruction.component.routeData.data['activeTab'];
    }
    return false;
  }
}

How does Java resolve a relative path in new File()?

On windows and Netbeans you can set the relative path as:

    new FileReader("src\\PACKAGE_NAME\\FILENAME");

On Linux and Netbeans you can set the relative path as:

    new FileReader("src/PACKAGE_NAME/FILENAME");

If you have your code inside Source Packages I do not know if it is the same for eclipse or other IDE

upstream sent too big header while reading response header from upstream

If you're using Symfony framework: Before messing with Nginx config, try to disable ChromePHP first.

1 - Open app/config/config_dev.yml

2 - Comment these lines:

#chromephp:
    #type:   chromephp
    #level:  info

ChromePHP pack the debug info json-encoded in the X-ChromePhp-Data header, which is too big for the default config of nginx with fastcgi.

Source: https://github.com/symfony/symfony/issues/8413#issuecomment-20412848

How to concatenate int values in java?

If you multiply b by 1000, you will not lose any of the values. See below for the math.

10000
    0
  200
   20
    1
=====
10221

How to change the new TabLayout indicator color and height

Since I can't post a follow-up to android developer's comment, here's an updated answer for anyone else who needs to programmatically set the selected tab indicator color:

tabLayout.setSelectedTabIndicatorColor(Color.parseColor("#FFFFFF"));

Similarly, for height:

tabLayout.setSelectedTabIndicatorHeight((int) (2 * getResources().getDisplayMetrics().density));

These methods were only recently added to revision 23.0.0 of the Support Library, which is why Soheil Setayeshi's answer uses reflection.

How do I obtain the frequencies of each value in an FFT?

I have used the following:

public static double Index2Freq(int i, double samples, int nFFT) {
  return (double) i * (samples / nFFT / 2.);
}

public static int Freq2Index(double freq, double samples, int nFFT) {
  return (int) (freq / (samples / nFFT / 2.0));
}

The inputs are:

• i: Bin to access
• samples: Sampling rate in Hertz (i.e. 8000 Hz, 44100Hz, etc.)
• nFFT: Size of the FFT vector

align an image and some text on the same line without using div width?

Floating will result in wrapping if space is not available.

You can use display:inline and white-space:nowrap to achieve this. Fiddle

<div id="container" style="white-space:nowrap">

    <div id="image" style="display:inline;">
        <img src="tree.png"/>
    </div>

    <div id="texts" style="display:inline; white-space:nowrap;"> 
        A very long text(about 300 words) 
    </div>

</div>?

Combining a class selector and an attribute selector with jQuery

I think you just need to remove the space. i.e.

$(".myclass[reference=12345]").css('border', '#000 solid 1px');

There is a fiddle here http://jsfiddle.net/xXEHY/

What does on_delete do on Django models?

Reorient your mental model of the functionality of "CASCADE" by thinking of adding a FK to an already existing cascade (i.e. a waterfall). The source of this waterfall is a primary key (PK). Deletes flow down.

So if you define a FK's on_delete as "CASCADE," you're adding this FK's record to a cascade of deletes originating from the PK. The FK's record may participate in this cascade or not ("SET_NULL"). In fact, a record with a FK may even prevent the flow of the deletes! Build a dam with "PROTECT."

Switch firefox to use a different DNS than what is in the windows.host file

Go to options->Advanced->Network->Settings->Automatic proxy configuration url and enter 8.8.8.8 All you Mozilla traffic uses Google dns now.

Render partial view with dynamic model in Razor view engine and ASP.NET MVC 3

There's another reason that this can be thrown, even if you're not using dynamic/ExpandoObject. If you are doing a loop, like this:

@foreach (var folder in ViewBag.RootFolder.ChildFolders.ToList())
{
    @Html.Partial("ContentFolderTreeViewItems", folder)
}

In that case, the "var" instead of the type declaration will throw the same error, despite the fact that RootFolder is of type "Folder. By changing the var to the actual type, the problem goes away.

@foreach (ContentFolder folder in ViewBag.RootFolder.ChildFolders.ToList())
{
    @Html.Partial("ContentFolderTreeViewItems", folder)
}

Where can I download an offline installer of Cygwin?

Not a direct answer to your question, but you can get the most commonly used utilities from http://www.mingw.org/ without having to jump through the hoops with that horrible Cygwin installer.

Here is a slightly more informative link http://sourceforge.net/apps/mediawiki/cobcurses/index.php?title=Install-MSYS.

Application_Start not firing?

I had made some changes based on "Code Analysis on Build" from Visual Studio. Code Analysis suggested "CA1822 Mark members as static" for Application_Start() in Global.asax. I did that and ended up with this problem.

I suggest suppressing this Code Analysis message, and not alter the signature of methods/classes automatically created by platform used for bootstrapping the Application. The signature of the method Application_Start probably was non-static for a reason.

I reverted to this method-signature and Application_Start() was firing again:

    protected void Application_Start()
    { ... }

To compare two elements(string type) in XSLT?

First of all, the provided long code:

    <xsl:choose>
        <xsl:when test="OU_NAME='OU_ADDR1'">   --comparing two elements coming from XML             
            <!--remove if  adrees already contain  operating unit name <xsl:value-of select="OU_NAME"/> <fo:block/>-->
            <xsl:if test="OU_ADDR1 !='' ">
                <xsl:value-of select="OU_ADDR1"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR2 !='' ">
                <xsl:value-of select="OU_ADDR2"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR3 !='' ">
                <xsl:value-of select="OU_ADDR3"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="OU_TOWN_CITY !=''">
                <xsl:value-of select="OU_TOWN_CITY"/>,
                <fo:leader leader-pattern="space" leader-length="2.0pt"/>
            </xsl:if>
            <xsl:value-of select="OU_REGION2"/>
            <fo:leader leader-pattern="space" leader-length="3.0pt"/>
            <xsl:value-of select="OU_POSTALCODE"/>
            <fo:block/>
            <xsl:value-of select="OU_COUNTRY"/>
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of select="OU_NAME"/>
            <fo:block/>
            <xsl:if test="OU_ADDR1 !='' ">
                <xsl:value-of select="OU_ADDR1"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR2 !='' ">
                <xsl:value-of select="OU_ADDR2"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR3 !='' ">
                <xsl:value-of select="OU_ADDR3"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="OU_TOWN_CITY !=''">
                <xsl:value-of select="OU_TOWN_CITY"/>,
                <fo:leader leader-pattern="space" leader-length="2.0pt"/>
            </xsl:if>
            <xsl:value-of select="OU_REGION2"/>
            <fo:leader leader-pattern="space" leader-length="3.0pt"/>
            <xsl:value-of select="OU_POSTALCODE"/>
            <fo:block/>
            <xsl:value-of select="OU_COUNTRY"/>
        </xsl:otherwise>
    </xsl:choose>

is equivalent to this, much shorter code:

<xsl:if test="not(OU_NAME='OU_ADDR1)'">
              <xsl:value-of select="OU_NAME"/>
        </xsl:if>
            <xsl:if test="OU_ADDR1 !='' ">
                <xsl:value-of select="OU_ADDR1"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR2 !='' ">
                <xsl:value-of select="OU_ADDR2"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR3 !='' ">
                <xsl:value-of select="OU_ADDR3"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="OU_TOWN_CITY !=''">
                <xsl:value-of select="OU_TOWN_CITY"/>,
                <fo:leader leader-pattern="space" leader-length="2.0pt"/>
            </xsl:if>
            <xsl:value-of select="OU_REGION2"/>
            <fo:leader leader-pattern="space" leader-length="3.0pt"/>
            <xsl:value-of select="OU_POSTALCODE"/>
            <fo:block/>
            <xsl:value-of select="OU_COUNTRY"/>

Now, to your question:

how to compare two elements coming from xml as string

In Xpath 1.0 strings can be compared only for equality (or inequality), using the operator = and the function not() together with the operator =.

$str1 = $str2

evaluates to true() exactly when the string $str1 is equal to the string $str2.

not($str1 = $str2)

evaluates to true() exactly when the string $str1 is not equal to the string $str2.

There is also the != operator. It generally should be avoided because it has anomalous behavior whenever one of its operands is a node-set.

Now, the rules for comparing two element nodes are similar:

$el1 = $el2

evaluates to true() exactly when the string value of $el1 is equal to the string value of $el2.

not($el1 = $el2)

evaluates to true() exactly when the string value of $el1 is not equal to the string value of $el2.

However, if one of the operands of = is a node-set, then

 $ns = $str

evaluates to true() exactly when there is at least one node in the node-set $ns1, whose string value is equal to the string $str

$ns1 = $ns2

evaluates to true() exactly when there is at least one node in the node-set $ns1, whose string value is equal to the string value of some node from $ns2

Therefore, the expression:

OU_NAME='OU_ADDR1'

evaluates to true() only when there is at least one element child of the current node that is named OU_NAME and whose string value is the string 'OU_ADDR1'.

This is obviously not what you want!

Most probably you want:

OU_NAME=OU_ADDR1

This expression evaluates to true exactly there is at least one OU_NAME child of the current node and one OU_ADDR1 child of the current node with the same string value.

Finally, in XPath 2.0, strings can be compared also using the value comparison operators lt, le, eq, gt, ge and the inherited from XPath 1.0 general comparison operator =.

Trying to evaluate a value comparison operator when one or both of its arguments is a sequence of more than one item results in error.

What does "Changes not staged for commit" mean

You may see this error when you have added a new file to your code and you're now trying to commit the code without staging(adding) it.

To overcome this, you may first add the file by using git add (git add your_file_name.py) and then committing the changes (git commit -m "Rename Files" -m "Sample script to rename files as you like")

Xlib: extension "RANDR" missing on display ":21". - Trying to run headless Google Chrome

It seems that when this error appears it is an indication that the selenium-java plugin for maven is out-of-date.

Changing the version in the pom.xml should fix the problem

Tomcat 7.0.43 "INFO: Error parsing HTTP request header"

In our case it turned out that the error happened because we have a custom filter in our application which does HttpServletResponse sendRedirect() to other url.

For some reason, the redirection is not closing the keep-alive status of the connection, hence the timeout exception.

We checked with Tomcat Docs and when we disabled the maxKeepAliveRequests by setting it's value to 1 and the error stopped showing up.

For now we do not have the actual solution to the error.

GIT commit as different user without email / or only email

Just supplement:

git commit --author="[email protected] " -m "Impersonation is evil."

In some cases the commit still fails and shows you the following message:

*** Please tell me who you are.

Run

git config --global user.email "[email protected]" git config --global user.name "Your Name"

to set your account's default identity. Omit --global to set the identity only in this repository.

fatal: unable to auto-detect email address (got xxxx)

So just run "git config", then "git commit"

How do I check the difference, in seconds, between two dates?

We have function total_seconds() with Python 2.7 Please see below code for python 2.6

import datetime
import time  

def diffdates(d1, d2):
    #Date format: %Y-%m-%d %H:%M:%S
    return (time.mktime(time.strptime(d2,"%Y-%m-%d %H:%M:%S")) -
               time.mktime(time.strptime(d1, "%Y-%m-%d %H:%M:%S")))

d1 = datetime.now()
d2 = datetime.now() + timedelta(days=1)
diff = diffdates(d1, d2)

Eclipse projects not showing up after placing project files in workspace/projects

I had the same problem over and over again the solution that a have found works for now

1. Close Eclipse.
2. go to workspace.metadata.plugins
3. remove org.eclipse.core.resources
4. Start Eclipse
5. Do File->Import
6. General->Existing Projects into Workspace and import all the project from the workspace

unable to set private key file: './cert.pem' type PEM

After reading cURL documentation on the options you used, it looks like the private key of certificate is not in the same file. If it is in different file, you need to mention it using --key file and supply passphrase.

So, please make sure that either cert.pem has private key (along with the certificate) or supply it using --key option.

Also, this documentation mentions that Note that this option assumes a "certificate" file that is the private key and the private certificate concatenated!

How they are concatenated? It is quite easy. Put them one after another in the same file.

You can get more help on this here.

I believe this might help you.

dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib

If you are using ruby-2.7.0 on MacOS Catalina 10.15

$ brew reinstall [email protected]

or

$ rvm reinstall 2.7.0
$ brew tap --repair
$ brew doctor

Pass value to iframe from a window

Two more options, which are not the most elegant but probably easier to understand and implement, especially in case the data that the iframe needs from its parent is just a few vars, not complex objects:

Using the URL Fragment Identifier (#)

In the container:

<iframe name="frame-id" src="http://url_to_iframe#dataToFrame"></iframe>

In the iFrame:

<script>
var dataFromDocument = location.hash.replace(/#/, "");
alert(dataFromDocument); //alerts "dataToFrame"
</script>

Use the iFrame's name

(I don't like this solution - it's abusing the name attribute, but it's an option so I'm mentioning it for the record)

In the container:

<iframe name="dataToFrame" src="http://url_to_iframe"></iframe>

In the iFrame:

<script type="text/javascript">
alert(window.name); // alerts "dataToFrame"
</script>

The name 'ConfigurationManager' does not exist in the current context

For a sanity check, try creating a new Web Application Project, open the code behind for the Default.aspx page. Add a line in Page_Load to access your connection string.

It should have System.Configuration added as reference by default. You should also see the using statement at the top of your code file already.

My code behind file now looks like this and compiles with no problems.

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

namespace WebApplication1
{
  public partial class _Default : System.Web.UI.Page
  {
    protected void Page_Load(object sender, EventArgs e)
    {
      string connString = ConfigurationManager.ConnectionStrings["MyConnectionStringName"].ConnectionString;
    }
  }
}

This assumes I have a connection string in my web.config with a name equal to "MyConnectionStringName" like so...

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="MyConnectionStringName"
            connectionString="Data Source=.;Initial Catalog=MyDatabase;Integrated Security=True"
            providerName="System.Data.SqlClient" />
    </connectionStrings>
</configuration>

Yeah, it's elementary I know. But if you don't have any better ideas sometimes it helps to check against something really simple that you know should work.

How do I get a list of folders and sub folders without the files?

dir /ad /b /s will give the required answer.

Configure apache to listen on port other than 80

Run this command if your ufw(Uncomplicatd Firewall) is enabled . Add for Example port 8080

$ sudo ufw allow 8080/tcp

And you can check the status by running

$ sudo ufw status

For more info check : https://linuxhint.com/ubuntu_allow_port_firewall

How to iterate through SparseArray?

Here is simple Iterator<T> and Iterable<T> implementations for SparseArray<T>:

public class SparseArrayIterator<T> implements Iterator<T> {
    private final SparseArray<T> array;
    private int index;

    public SparseArrayIterator(SparseArray<T> array) {
        this.array = array;
    }

    @Override
    public boolean hasNext() {
        return array.size() > index;
    }

    @Override
    public T next() {
        return array.valueAt(index++);
    }

    @Override
    public void remove() {
        array.removeAt(index);
    }

}

public class SparseArrayIterable<T> implements Iterable<T> {
    private final SparseArray<T> sparseArray;

    public SparseArrayIterable(SparseArray<T> sparseArray) {
        this.sparseArray = sparseArray;
    }

    @Override
    public Iterator<T> iterator() {
        return new SparseArrayIterator<>(sparseArray);
    }
}

If you want to iterate not only a value but also a key:

public class SparseKeyValue<T> {
    private final int key;
    private final T value;

    public SparseKeyValue(int key, T value) {
        this.key = key;
        this.value = value;
    }

    public int getKey() {
        return key;
    }

    public T getValue() {
        return value;
    }
}

public class SparseArrayKeyValueIterator<T> implements Iterator<SparseKeyValue<T>> {
    private final SparseArray<T> array;
    private int index;

    public SparseArrayKeyValueIterator(SparseArray<T> array) {
        this.array = array;
    }

    @Override
    public boolean hasNext() {
        return array.size() > index;
    }

    @Override
    public SparseKeyValue<T> next() {
        SparseKeyValue<T> keyValue = new SparseKeyValue<>(array.keyAt(index), array.valueAt(index));
        index++;
        return keyValue;
    }

    @Override
    public void remove() {
        array.removeAt(index);
    }

}

public class SparseArrayKeyValueIterable<T> implements Iterable<SparseKeyValue<T>> {
    private final SparseArray<T> sparseArray;

    public SparseArrayKeyValueIterable(SparseArray<T> sparseArray) {
        this.sparseArray = sparseArray;
    }

    @Override
    public Iterator<SparseKeyValue<T>> iterator() {
        return new SparseArrayKeyValueIterator<T>(sparseArray);
    }
}

It's useful to create utility methods that return Iterable<T> and Iterable<SparseKeyValue<T>>:

public abstract class SparseArrayUtils {
    public static <T> Iterable<SparseKeyValue<T>> keyValueIterable(SparseArray<T> sparseArray) {
        return new SparseArrayKeyValueIterable<>(sparseArray);
    }

    public static <T> Iterable<T> iterable(SparseArray<T> sparseArray) {
        return new SparseArrayIterable<>(sparseArray);
    }
}

Now you can iterate SparseArray<T>:

SparseArray<String> a = ...;

for (String s: SparseArrayUtils.iterable(a)) {
   // ...
}

for (SparseKeyValue<String> s: SparseArrayUtils.keyValueIterable(a)) {
  // ...
}

Truncate number to two decimal places without rounding

Update (Jan 2021)

Depending on its range, a number in javascript may be shown in scientific notation. For example, if you type 0.0000001 in the console, you may see it as 1e-7, whereas 0.000001 appears unchanged (0.000001). If your application works on a range of numbers for which scientific notation is not involved, you can just ignore this update and use the original answer below.

This update is about adding a function that checks if the number is in scientific format and, if so, converts it into decimal format. Here I'm proposing this one, but you can use any other function that achieves the same goal, according to your application's needs:

function toFixed(x) {
  if (Math.abs(x) < 1.0) {
    var e = parseInt(x.toString().split('e-')[1]);
    if (e) {
        x *= Math.pow(10,e-1);
        x = '0.' + (new Array(e)).join('0') + x.toString().substring(2);
    }
  } else {
    var e = parseInt(x.toString().split('+')[1]);
    if (e > 20) {
        e -= 20;
        x /= Math.pow(10,e);
        x += (new Array(e+1)).join('0');
    }
  }
  return x;
}

Now just apply that function to the parameter (that's the only change with respect to the original answer):

function toFixedTrunc(x, n) {
      x = toFixed(x) 

      // From here on the code is the same than the original answer
      const v = (typeof x === 'string' ? x : x.toString()).split('.');
      if (n <= 0) return v[0];
      let f = v[1] || '';
      if (f.length > n) return `${v[0]}.${f.substr(0,n)}`;
      while (f.length < n) f += '0';
      return `${v[0]}.${f}`
    }

This updated version addresses also a case mentioned in a comment:

toFixedTrunc(0.000000199, 2) => "0.00" 

Again, choose what fits your application needs at best.

Original answer (October 2017)

General solution to truncate (no rounding) a number to the n-th decimal digit and convert it to a string with exactly n decimal digits, for any n=0.

function toFixedTrunc(x, n) {
  const v = (typeof x === 'string' ? x : x.toString()).split('.');
  if (n <= 0) return v[0];
  let f = v[1] || '';
  if (f.length > n) return `${v[0]}.${f.substr(0,n)}`;
  while (f.length < n) f += '0';
  return `${v[0]}.${f}`
}

where x can be either a number (which gets converted into a string) or a string.

Here are some tests for n=2 (including the one requested by OP):

0           => 0.00
0.01        => 0.01
0.5839      => 0.58
0.999       => 0.99
1.01        => 1.01
2           => 2.00
2.551       => 2.55
2.99999     => 2.99
4.27        => 4.27
15.7784514  => 15.77
123.5999    => 123.59

And for some other values of n:

15.001097   => 15.0010 (n=4)
0.000003298 => 0.0000032 (n=7)
0.000003298257899 => 0.000003298257 (n=12)

Use String.split() with multiple delimiters

String[] token=s.split("[.-]");

How to remove MySQL completely with config and library files?

With the command:

sudo apt-get remove --purge mysql\*

you can delete anything related to packages named mysql. Those commands are only valid on debian / debian-based linux distributions (Ubuntu for example).

You can list all installed mysql packages with the command:

sudo dpkg -l | grep -i mysql

For more cleanup of the package cache, you can use the command:

sudo apt-get clean

Also, remember to use the command:

sudo updatedb

Otherwise the "locate" command will display old data.

To install mysql again, use the following command:

sudo apt-get install libmysqlclient-dev mysql-client

This will install the mysql client, libmysql and its headers files.

To install the mysql server, use the command:

sudo apt-get install mysql-server

Removing legend on charts with chart.js v2

The options object can be added to the chart when the new Chart object is created.

var chart1 = new Chart(canvas, {
    type: "pie",
    data: data,
    options: {
         legend: {
            display: false
         },
         tooltips: {
            enabled: false
         }
    }
});

What is the best way to compare floats for almost-equality in Python?

If you want to use it in testing/TDD context, I'd say this is a standard way:

from nose.tools import assert_almost_equals

assert_almost_equals(x, y, places=7) #default is 7

Date Format in Swift

Place it in extension and call it like below. It's easy to use throughout the application.

self.getFormattedDate(strDate: "20-March-2019", currentFomat: "dd-MMM-yyyy", expectedFromat: "yyyy-MM-dd")

Implementation

func getFormattedDate(strDate: String , currentFomat:String, expectedFromat: String) -> String{
    let dateFormatterGet = DateFormatter()
    dateFormatterGet.dateFormat = currentFomat

    let date : Date = dateFormatterGet.date(from: strDate) ?? Date()

    dateFormatterGet.dateFormat = expectedFromat
    return dateFormatterGet.string(from: date)
}

What is the best way to redirect a page using React Router?

One of the simplest way: use Link as follows:

import { Link } from 'react-router-dom';

<Link to={`your-path`} activeClassName="current">{your-link-name}</Link>

If we want to cover the whole div section as link:

 <div>
     <Card as={Link} to={'path-name'}>
         .... 
           card content here
         ....
     </Card>
 </div>

What is the use of hashCode in Java?

hashCode() is used for bucketing in Hash implementations like HashMap, HashTable, HashSet, etc.

The value received from hashCode() is used as the bucket number for storing elements of the set/map. This bucket number is the address of the element inside the set/map.

When you do contains() it will take the hash code of the element, then look for the bucket where hash code points to. If more than 1 element is found in the same bucket (multiple objects can have the same hash code), then it uses the equals() method to evaluate if the objects are equal, and then decide if contains() is true or false, or decide if element could be added in the set or not.

Java: Get first item from a collection

Iterables.get(yourC, indexYouWant)

Because really, if you're using Collections, you should be using Google Collections.

Calculate difference between two dates (number of days)?

For beginners like me that will stumble upon this tiny problem, in a simple line, with sample conversion to int:

int totalDays = Convert.ToInt32((DateTime.UtcNow.Date - myDateTime.Date).TotalDays);

This calculates the total days from today (DateTime.UtcNow.Date) to a desired date (myDateTime.Date).

If myDateTime is yesterday, or older date than today, this will give a positive (+) integer result.

On the other side, if the myDateTime is tomorrow or on the future date, this will give a negative (-) integer result due to rules of addition.

Happy coding! ^_^

How do you fix a MySQL "Incorrect key file" error when you can't repair the table?

You'll need to run this command from the MySQL prompt:

REPAIR TABLE tbl_name USE_FRM;

From MySQL's documentation on the Repair command:

The USE_FRM option is available for use if the .MYI index file is missing or if its header is corrupted. This option tells MySQL not to trust the information in the .MYI file header and to re-create it using information from the .frm file. This kind of repair cannot be done with myisamchk.