Programs & Examples On #Jca

The Java Connector Architecture (JCA) defines a standard architecture for connecting the Java EE platform to heterogeneous Enterprise Information Systems (EIS). Examples of EISs include Enterprise Resource Planning (ERP), mainframe transaction processing (TP), database and messaging systems

Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

Ok - for me the source of the problem was in serialisation/deserialisation. The object that was being sent and received was as follows where the code is submitted and the code and maskedPhoneNumber is returned.

@ApiObject(description = "What the object is for.")
@JsonIgnoreProperties(ignoreUnknown = true)
public class CodeVerification {

    @ApiObjectField(description = "The code which is to be verified.")
    @NotBlank(message = "mandatory")
    private final String code;

    @ApiObjectField(description = "The masked mobile phone number to which the code was verfied against.")
    private final String maskedMobileNumber;

    public codeVerification(@JsonProperty("code") String code, String maskedMobileNumber) {
        this.code = code;
        this.maskedMobileNumber = maskedMobileNumber;
    }

    public String getcode() {
        return code;
    }

    public String getMaskedMobileNumber() {
        return maskedMobileNumber;
    }
}

The problem was that I didn't have a JsonProperty defined for the maskedMobileNumber in the constructor. i.e. Constructor should have been

public codeVerification(@JsonProperty("code") String code, @JsonProperty("maskedMobileNumber") String maskedMobileNumber) {
    this.code = code;
    this.maskedMobileNumber = maskedMobileNumber;
}

Excel VBA Code: Compile Error in x64 Version ('PtrSafe' attribute required)

I think all you need to do for your function is just add PtrSafe: i.e. the first line of your first function should look like this:

Private Declare PtrSafe Function swe_azalt Lib "swedll32.dll" ......

Caused by: java.security.UnrecoverableKeyException: Cannot recover key

Check if password you are using is correct one by running below command

keytool -keypasswd -new temp123 -keystore awsdemo-keystore.jks -storepass temp123 -alias movie-service -keypass changeit

If you are getting below error then your password is wrong

keytool error: java.security.UnrecoverableKeyException: Cannot recover key

how to save canvas as png image?

I really like Tovask's answer but it doesn't work due to the function having the name download (this answer explains why). I also don't see the point in replacing "data:image/..." with "data:application/...".

The following code has been tested in Chrome and Firefox and seems to work fine in both.

JavaScript:

function prepDownload(a, canvas, name) {
    a.download = name
    a.href = canvas.toDataURL()
}

HTML:

<a href="#" onclick="prepDownload(this, document.getElementById('canvasId'), 'imgName.png')">Download</a>
<canvas id="canvasId"></canvas>

Div Background Image Z-Index Issue

For z-index to work, you also need to give it a position:

header {
    width: 100%;
    height: 100px;
    background: url(../img/top.png) repeat-x;
    z-index: 110;
    position: relative;
}

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

Check the output before the statement that caused current transaction is aborted. This typically means that database threw an exception that your code had ignored and now expecting next queries to return some data.

So you now have a state mismatch between your application, which considers things are fine, and database, that requires you to rollback and re-start your transaction from the beginning.

You should catch all exceptions and rollback transactions in such cases.

Here's a similar issue.

Uncaught ReferenceError: jQuery is not defined

For one, you don't seem to be including jQuery itself in the header but only a bunch of plugins. As for the '<' error, it's impossible to tell without seeing the generated HTML.

Python base64 data decode

Note Slipstream's response, that base64.b64encode and base64.b64decode need bytes-like object, not string.

>>> import base64
>>> a = '{"name": "John", "age": 42}'
>>> base64.b64encode(a)
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/lib/python3.6/base64.py", line 58, in b64encode
    encoded = binascii.b2a_base64(s, newline=False)
TypeError: a bytes-like object is required, not 'str'

How to read data from a file in Lua

Just a little addition if one wants to parse a space separated text file line by line.

read_file = function (path)
local file = io.open(path, "rb") 
if not file then return nil end

local lines = {}

for line in io.lines(path) do
    local words = {}
    for word in line:gmatch("%w+") do 
        table.insert(words, word) 
    end    
  table.insert(lines, words)
end

file:close()
return lines;
end

Removing a model in rails (reverse of "rails g model Title...")

For future questioners: If you can't drop the tables from the console, try to create a migration that drops the tables for you. You should create a migration and then in the file note tables you want dropped like this:

class DropTables < ActiveRecord::Migration
  def up
    drop_table :table_you_dont_want
  end

  def down
    raise ActiveRecord::IrreversibleMigration
  end
end

Configure WAMP server to send email

Configuring a working email client from localhost is quite a chore, I have spent hours of frustration attempting it. I'm sure someone more experienced may be able to help, or they may perhaps agree with me.

If you just want to test, here is a great tool for testing mail locally, that requires almost no configuration:

http://www.toolheap.com/test-mail-server-tool/

It worked right off the bat for me, hope this helps you.

What is the difference between task and thread?

A Task can be seen as a convenient and easy way to execute something asynchronously and in parallel.

Normally a Task is all you need, I cannot remember if I have ever used a thread for something else than experimentation.

You can accomplish the same with a thread (with lots of effort) as you can with a task.

Thread

int result = 0;
Thread thread = new System.Threading.Thread(() => { 
    result = 1; 
});
thread.Start();
thread.Join();
Console.WriteLine(result); //is 1

Task

int result = await Task.Run(() => {
    return 1; 
});
Console.WriteLine(result); //is 1

A task will by default use the Threadpool, which saves resources as creating threads can be expensive. You can see a Task as a higher level abstraction upon threads.

As this article points out, task provides following powerful features over thread.

  • Tasks are tuned for leveraging multicores processors.

  • If system has multiple tasks then it make use of the CLR thread pool internally, and so do not have the overhead associated with creating a dedicated thread using the Thread. Also reduce the context switching time among multiple threads.

  • Task can return a result.There is no direct mechanism to return the result from thread.
  • Wait on a set of tasks, without a signaling construct.

  • We can chain tasks together to execute one after the other.

  • Establish a parent/child relationship when one task is started from another task.

  • Child task exception can propagate to parent task.

  • Task support cancellation through the use of cancellation tokens.

  • Asynchronous implementation is easy in task, using’ async’ and ‘await’ keywords.

Pandas read_sql with parameters

The read_sql docs say this params argument can be a list, tuple or dict (see docs).

To pass the values in the sql query, there are different syntaxes possible: ?, :1, :name, %s, %(name)s (see PEP249).
But not all of these possibilities are supported by all database drivers, which syntax is supported depends on the driver you are using (psycopg2 in your case I suppose).

In your second case, when using a dict, you are using 'named arguments', and according to the psycopg2 documentation, they support the %(name)s style (and so not the :name I suppose), see http://initd.org/psycopg/docs/usage.html#query-parameters.
So using that style should work:

df = psql.read_sql(('select "Timestamp","Value" from "MyTable" '
                     'where "Timestamp" BETWEEN %(dstart)s AND %(dfinish)s'),
                   db,params={"dstart":datetime(2014,6,24,16,0),"dfinish":datetime(2014,6,24,17,0)},
                   index_col=['Timestamp'])

Comparing arrays for equality in C++

Nobody mentions memcmp? This is also a good choice.

/* memcmp example */
#include <stdio.h>
#include <string.h>

int main ()
{
  char buffer1[] = "DWgaOtP12df0";
  char buffer2[] = "DWGAOTP12DF0";

  int n;

  n=memcmp ( buffer1, buffer2, sizeof(buffer1) );

  if (n>0) printf ("'%s' is greater than '%s'.\n",buffer1,buffer2);
  else if (n<0) printf ("'%s' is less than '%s'.\n",buffer1,buffer2);
  else printf ("'%s' is the same as '%s'.\n",buffer1,buffer2);

  return 0;
}

Ref: http://www.cplusplus.com/reference/cstring/memcmp/

Good Patterns For VBA Error Handling

I find the following to work best, called the central error handling approach.

Benefits

You have 2 modes of running your application: Debug and Production. In the Debug mode, the code will stop at any unexpected error and allow you to debug easily by jumping to the line where it occurred by pressing F8 twice. In the Production mode, a meaningful error message will get displayed to the user.

You can throw intentional errors like this, which will stop execution of the code with a message to the user:

Err.Raise vbObjectError, gsNO_DEBUG, "Some meaningful error message to the user"

Err.Raise vbObjectError, gsUSER_MESSAGE, "Some meaningful non-error message to the user"

'Or to exit in the middle of a call stack without a message:
Err.Raise vbObjectError, gsSILENT

Implementation

You need to "wrap" all subroutines and functions with any significant amount of code with the following headers and footers, making sure to specify ehCallTypeEntryPoint in all your entry points. Note the msModule constant as well, which needs to be put in all modules.

Option Explicit
Const msModule As String = "<Your Module Name>"

' This is an entry point 
Public Sub AnEntryPoint()
    Const sSOURCE As String = "AnEntryPoint"
    On Error GoTo ErrorHandler

    'Your code

ErrorExit:
    Exit Sub

ErrorHandler:
    If CentralErrorHandler(Err, ThisWorkbook, msModule, sSOURCE, ehCallTypeEntryPoint) Then
        Stop
        Resume
    Else
        Resume ErrorExit
    End If
End Sub

' This is any other subroutine or function that isn't an entry point
Sub AnyOtherSub()
    Const sSOURCE As String = "AnyOtherSub"
    On Error GoTo ErrorHandler

    'Your code

ErrorExit:
    Exit Sub

ErrorHandler:
    If CentralErrorHandler(Err, ThisWorkbook, msModule, sSOURCE) Then
        Stop
        Resume
    Else
        Resume ErrorExit
    End If
End Sub

The contents of the central error handler module is the following:

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Comments: Error handler code.
'
'           Run SetDebugMode True to use debug mode (Dev mode)
'           It will be False by default (Production mode)
'
' Author:   Igor Popov
' Date:     13 Feb 2014
' Licence:  MIT
'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

Option Explicit
Option Private Module

Private Const msModule As String = "MErrorHandler"

Public Const gsAPP_NAME As String = "<You Application Name>"

Public Const gsSILENT As String = "UserCancel"  'A silent error is when the user aborts an action, no message should be displayed
Public Const gsNO_DEBUG As String = "NoDebug"   'This type of error will display a specific message to the user in situation of an expected (provided-for) error.
Public Const gsUSER_MESSAGE As String = "UserMessage" 'Use this type of error to display an information message to the user

Private Const msDEBUG_MODE_COMPANY = "<Your Company>"
Private Const msDEBUG_MODE_SECTION = "<Your Team>"
Private Const msDEBUG_MODE_VALUE = "DEBUG_MODE"

Public Enum ECallType
    ehCallTypeRegular = 0
    ehCallTypeEntryPoint
End Enum

Public Function DebugMode() As Boolean
    DebugMode = CBool(GetSetting(msDEBUG_MODE_COMPANY, msDEBUG_MODE_SECTION, msDEBUG_MODE_VALUE, 0))
End Function

Public Sub SetDebugMode(Optional bMode As Boolean = True)
    SaveSetting msDEBUG_MODE_COMPANY, msDEBUG_MODE_SECTION, msDEBUG_MODE_VALUE, IIf(bMode, 1, 0)
End Sub

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Comments: The central error handler for all functions
'           Displays errors to the user at the entry point level, or, if we're below the entry point, rethrows it upwards until the entry point is reached
'
'           Returns True to stop and debug unexpected errors in debug mode.
'
'           The function can be enhanced to log errors.
'
' Date          Developer           TDID    Comment
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' 13 Feb 2014   Igor Popov                  Created

Public Function CentralErrorHandler(ErrObj As ErrObject, Wbk As Workbook, ByVal sModule As String, ByVal sSOURCE As String, _
                                    Optional enCallType As ECallType = ehCallTypeRegular, Optional ByVal bRethrowError As Boolean = True) As Boolean

    Static ssModule As String, ssSource As String
    If Len(ssModule) = 0 And Len(ssSource) = 0 Then
        'Remember the module and the source of the first call to CentralErrorHandler
        ssModule = sModule
        ssSource = sSOURCE
    End If
    CentralErrorHandler = DebugMode And ErrObj.Source <> gsNO_DEBUG And ErrObj.Source <> gsUSER_MESSAGE And ErrObj.Source <> gsSILENT
    If CentralErrorHandler Then
        'If it's an unexpected error and we're going to stop in the debug mode, just write the error message to the immediate window for debugging
        Debug.Print "#Err: " & Err.Description
    ElseIf enCallType = ehCallTypeEntryPoint Then
        'If we have reached the entry point and it's not a silent error, display the message to the user in an error box
        If ErrObj.Source <> gsSILENT Then
            Dim sMsg As String: sMsg = ErrObj.Description
            If ErrObj.Source <> gsNO_DEBUG And ErrObj.Source <> gsUSER_MESSAGE Then sMsg = "Unexpected VBA error in workbook '" & Wbk.Name & "', module '" & ssModule & "', call '" & ssSource & "':" & vbCrLf & vbCrLf & sMsg
            MsgBox sMsg, vbOKOnly + IIf(ErrObj.Source = gsUSER_MESSAGE, vbInformation, vbCritical), gsAPP_NAME
        End If
    ElseIf bRethrowError Then
        'Rethrow the error to the next level up if bRethrowError is True (by Default).
        'Otherwise, do nothing as the calling function must be having special logic for handling errors.
        Err.Raise ErrObj.Number, ErrObj.Source, ErrObj.Description
    End If
End Function

To set yourself in the Debug mode, run the following in the Immediate window:

SetDebugMode True

Execute and get the output of a shell command in node.js

You can use the util library that comes with nodejs to get a promise from the exec command and can use that output as you need. Use restructuring to store the stdout and stderr in variables.

_x000D_
_x000D_
const util = require('util');
const exec = util.promisify(require('child_process').exec);

async function lsExample() {
  const {
    stdout,
    stderr
  } = await exec('ls');
  console.log('stdout:', stdout);
  console.error('stderr:', stderr);
}
lsExample();
_x000D_
_x000D_
_x000D_

jQuery Array of all selected checkboxes (by class)

You can also add underscore.js to your project and will be able to do it in one line:

_.map($("input[name='category_ids[]']:checked"), function(el){return $(el).val()})

How to display activity indicator in middle of the iphone screen?

Try this way

UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    activityIndicator.frame = CGRectMake(10.0, 0.0, 40.0, 40.0);
    activityIndicator.center = super_view.center;
    [super_view addSubview: activityIndicator];

[activityIndicator startAnimating];

Remove all unused resources from an android project

Attention Android Wear developers: "Remove Unused Resources" will delete the xml file where you declare the capability name (res/values/wear.xml) and the phone won't be able to connect to the watch. I spent hours trying to figure out this bug in my app.

How to make a new List in Java

List list = new ArrayList();

Or with generics

List<String> list = new ArrayList<String>();

You can, of course, replace string with any type of variable, such as Integer, also.

Oracle - Best SELECT statement for getting the difference in minutes between two DateTime columns?

By default, oracle date subtraction returns a result in # of days.

So just multiply by 24 to get # of hours, and again by 60 for # of minutes.

Example:

select
  round((second_date - first_date) * (60 * 24),2) as time_in_minutes
from
  (
  select
    to_date('01/01/2008 01:30:00 PM','mm/dd/yyyy hh:mi:ss am') as first_date
   ,to_date('01/06/2008 01:35:00 PM','mm/dd/yyyy HH:MI:SS AM') as second_date
  from
    dual
  ) test_data

sorting dictionary python 3

A modern and fast solution, for Python 3.7. May also work in some interpreters of Python 3.6.

TLDR

To sort a dictionary by keys use:

sorted_dict = {k: disordered[k] for k in sorted(disordered)}

Almost three times faster than the accepted answer; probably more when you include imports.

Comment on the accepted answer

The example in the accepted answer instead of iterating over the keys only - with key parameter of sorted() or the default behaviour of dict iteration - iterates over tuples (key, value), which suprisingly turns out to be much slower than comparing the keys only and accessing dictionary elements in a list comprehension.

How to sort by key in Python 3.7

The big change in Python 3.7 is that the dictionaries are now ordered by default.

  • You can generate sorted dict using dict comprehensions.
  • Using OrderedDict might still be preferable for the compatibility sake.
  • Do not use sorted(d.items()) without key.

See:

disordered = {10: 'b', 3: 'a', 5: 'c'}

# sort keys, then get values from original - fast
sorted_dict = {k: disordered[k] for k in sorted(disordered)}

# key = itemgetter - slower
from operator import itemgetter
key = itemgetter(0)
sorted_dict = {k: v for k, v in sorted(disordered.items(), key=key)}

# key = lambda - the slowest
key = lambda item: item[0]
sorted_dict = {k: v for k in sorted(disordered.items(), key=key)} 

Timing results:

Best for {k: d[k] for k in sorted(d)}: 7.507327548999456
Best for {k: v for k, v in sorted(d.items(), key=key_getter)}: 12.031082626002899
Best for {k: v for k, v in sorted(d.items(), key=key_lambda)}: 14.22885995300021

Best for dict(sorted(d.items(), key=key_getter)): 11.209122000000207
Best for dict(sorted(d.items(), key=key_lambda)): 13.289728325995384
Best for dict(sorted(d.items())): 14.231471302999125

Best for OrderedDict(sorted(d.items(), key=key_getter)): 16.609151654003654
Best for OrderedDict(sorted(d.items(), key=key_lambda)): 18.52622927199991
Best for OrderedDict(sorted(d.items())): 19.436101284998585

Testing code:

from timeit import repeat

setup_code = """
from operator import itemgetter
from collections import OrderedDict
import random
random.seed(0)
d = {i: chr(i) for i in [random.randint(0, 120) for repeat in range(120)]}
key_getter = itemgetter(0)
key_lambda = lambda item: item[0]
"""

cases = [
    # fast
    '{k: d[k] for k in sorted(d)}',
    '{k: v for k, v in sorted(d.items(), key=key_getter)}',
    '{k: v for k, v in sorted(d.items(), key=key_lambda)}',
    # slower
    'dict(sorted(d.items(), key=key_getter))',
    'dict(sorted(d.items(), key=key_lambda))',
    'dict(sorted(d.items()))',
    # the slowest 
    'OrderedDict(sorted(d.items(), key=key_getter))',
    'OrderedDict(sorted(d.items(), key=key_lambda))',
    'OrderedDict(sorted(d.items()))',
]

for code in cases:
    times = repeat(code, setup=setup_code, repeat=3)
    print(f"Best for {code}: {min(times)}")

Remove a specific string from an array of string

Define "remove".

Arrays are fixed length and can not be resized once created. You can set an element to null to remove an object reference;

for (int i = 0; i < myStringArray.length(); i++)
{
    if (myStringArray[i].equals(stringToRemove))
    {
        myStringArray[i] = null;
        break;
    }
}

or

myStringArray[indexOfStringToRemove] = null;

If you want a dynamically sized array where the object is actually removed and the list (array) size is adjusted accordingly, use an ArrayList<String>

myArrayList.remove(stringToRemove); 

or

myArrayList.remove(indexOfStringToRemove);

Edit in response to OP's edit to his question and comment below

String r = myArrayList.get(rgenerator.nextInt(myArrayList.size()));

SELECT DISTINCT on one column

I know it was asked over 6 years ago, but knowledge is still knowledge. This is different solution than all above, as I had to run it under SQL Server 2000:

DECLARE @TestData TABLE([ID] int, [SKU] char(6), [Product] varchar(15))
INSERT INTO @TestData values (1 ,'FOO-23', 'Orange')
INSERT INTO @TestData values (2 ,'BAR-23', 'Orange')
INSERT INTO @TestData values (3 ,'FOO-24', 'Apple')
INSERT INTO @TestData values (4 ,'FOO-25', 'Orange')

SELECT DISTINCT  [ID] = ( SELECT TOP 1 [ID]  FROM @TestData Y WHERE Y.[Product] = X.[Product])
                ,[SKU]= ( SELECT TOP 1 [SKU] FROM @TestData Y WHERE Y.[Product] = X.[Product])
                ,[PRODUCT] 
            FROM @TestData X  

Example on ToggleButton

<ToggleButton 
    android:id="@+id/togglebutton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textOn="Vibrate on"
    android:textOff="Vibrate off"
    android:onClick="onToggleClicked"/>

Within the Activity that hosts this layout, the following method handles the click event:

public void onToggleClicked(View view) {
    // Is the toggle on?
    boolean on = ((ToggleButton) view).isChecked();

    if (on) {
        // Enable vibrate
    } else {
        // Disable vibrate
    }
}

select data up to a space?

select left(col, charindex(' ', col) - 1)

Fixed height and width for bootstrap carousel

set style="height:300px !important;" and "imgBanner" for img tag.

<img src="/image/1.jpg" class="imgBanner" style="width:100%; height:300px !important;">

then if you want responsive image, so you can use jquery as:

$.(function(){
   $(window).resize(respWhenResize);
   respWhenResize();
 })



respWhenResize(){
 
       if (pagesize < 578) {
         $('.imgBanner').css('height','200px')
        } else if (pagesize > 578 ) {
            $('.imgBanner').css('height','300px')
        }
     }

Mysql - How to quit/exit from stored procedure

I think this solution is handy if you can test the value of the error field later. This is also applicable by creating a temporary table and returning a list of errors.

DROP PROCEDURE IF EXISTS $procName;
DELIMITER //
CREATE PROCEDURE $procName($params)
BEGIN
    DECLARE error INT DEFAULT 0;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET error = 1;
    SELECT
       $fields
    FROM $tables
    WHERE $where
    ORDER BY $sorting LIMIT 1
    INTO $vars;
    IF error = 0 THEN
       SELECT $vars;
    ELSE
       SELECT 1 AS error;
       SET @error = 0;
    END IF;
END//
CALL $procName($effp);

Format a Go string without printing?

I came to this page specifically looking for a way to format an error string. So if someone needs help with the same, you want to use the fmt.Errorf() function.

The method signature is func Errorf(format string, a ...interface{}) error. It returns the formatted string as a value that satisfies the error interface.

You can look up more details in the documentation - https://golang.org/pkg/fmt/#Errorf.

Working with TIFFs (import, export) in Python using numpy

I use matplotlib for reading TIFF files:

import matplotlib.pyplot as plt
I = plt.imread(tiff_file)

and I will be of type ndarray.

According to the documentation though it is actually PIL that works behind the scenes when handling TIFFs as matplotlib only reads PNGs natively, but this has been working fine for me.

There's also a plt.imsave function for saving.

Get a list of all git commits, including the 'lost' ones

git log --reflog

saved me! I lost mine while merging HEAD and could not find my lates commit! Not showing in source tree but git log --reflog show all my local commits before

Load content with ajax in bootstrap modal

Here is how I solved the issue, might be useful to some:

Ajax modal doesn't seem to be available with boostrap 2.1.1

So I ended up coding it myself:

$('[data-toggle="modal"]').click(function(e) {
  e.preventDefault();
  var url = $(this).attr('href');
  //var modal_id = $(this).attr('data-target');
  $.get(url, function(data) {
      $(data).modal();
  });
});

Example of a link that calls a modal:

<a href="{{ path('ajax_get_messages', { 'superCategoryID': 6, 'sex': sex }) }}" data-toggle="modal">
    <img src="{{ asset('bundles/yopyourownpoet/images/messageCategories/BirthdaysAnniversaries.png') }}" alt="Birthdays" height="120" width="109"/>
</a>

I now send the whole modal markup through ajax.

Credits to drewjoh

Can I make dynamic styles in React Native?

You can bind state value directly to style object. Here is an example:

class Timer extends Component{
 constructor(props){
 super(props);
 this.state = {timer: 0, color: '#FF0000'};
 setInterval(() => {
   this.setState({timer: this.state.timer + 1, color: this.state.timer % 2 == 0 ? '#FF0000' : '#0000FF'});
 }, 1000);
}

render(){
 return (
   <View>

    <Text>Timer:</Text>
    <Text style={{backgroundColor: this.state.color}}>{this.state.timer}</Text>
  </View>
 );
 }
}

How do I use hexadecimal color strings in Flutter?

if you want to use hex code of color which is in this format #123456 then it is very easily be used, create A variables of type Color and assign the following values to it.

Color myHexColor = Color(0xff123456) 

// her you notice I use the 0xff and that is opacity or transparency of the color 
// and you can also change these value .

use myhexcolor and you are ready to go .

if you want to change the opacity of color direct from the hex code then change the ff value in 0xff to the respectively value from the table below.

Hex Opacity Values

100% — FF

95% — F2

90% — E6

85% — D9

80% — CC

75% — BF

70% — B3

65% — A6

60% — 99

55% — 8C

50% — 80

45% — 73

40% — 66

35% — 59

30% — 4D

25% — 40

20% — 33

15% — 26

10% — 1A

5% — 0D

0% — 00

What are Runtime.getRuntime().totalMemory() and freeMemory()?

Codified version of all other answers (at the time of writing):

import java.io.*;

/**
 * This class is based on <a href="http://stackoverflow.com/users/2478930/cheneym">cheneym</a>'s
 * <a href="http://stackoverflow.com/a/18375641/253468">awesome interpretation</a>
 * of the Java {@link Runtime}'s memory query methods, which reflects intuitive thinking.
 * Also includes comments and observations from others on the same question, and my own experience.
 * <p>
 * <img src="https://i.stack.imgur.com/GjuwM.png" alt="Runtime's memory interpretation">
 * <p>
 * <b>JVM memory management crash course</b>:
 * Java virtual machine process' heap size is bounded by the maximum memory allowed.
 * The startup and maximum size can be configured by JVM arguments.
 * JVMs don't allocate the maximum memory on startup as the program running may never require that.
 * This is to be a good player and not waste system resources unnecessarily.
 * Instead they allocate some memory and then grow when new allocations require it.
 * The garbage collector will be run at times to clean up unused objects to prevent this growing.
 * Many parameters of this management such as when to grow/shrink or which GC to use
 * can be tuned via advanced configuration parameters on JVM startup.
 *
 * @see <a href="http://stackoverflow.com/a/42567450/253468">
 *     What are Runtime.getRuntime().totalMemory() and freeMemory()?</a>
 * @see <a href="http://www.oracle.com/technetwork/java/javase/memorymanagement-whitepaper-150215.pdf">
 *     Memory Management in the Sun Java HotSpot™ Virtual Machine</a>
 * @see <a href="http://docs.oracle.com/javase/8/docs/technotes/tools/windows/java.html">
 *     Full VM options reference for Windows</a>
 * @see <a href="http://docs.oracle.com/javase/8/docs/technotes/tools/unix/java.html">
 *     Full VM options reference for Linux, Mac OS X and Solaris</a>
 * @see <a href="http://www.oracle.com/technetwork/articles/java/vmoptions-jsp-140102.html">
 *     Java HotSpot VM Options quick reference</a>
 */
public class SystemMemory {

    // can be white-box mocked for testing
    private final Runtime runtime = Runtime.getRuntime();

    /**
     * <b>Total allocated memory</b>: space currently reserved for the JVM heap within the process.
     * <p>
     * <i>Caution</i>: this is not the total memory, the JVM may grow the heap for new allocations.
     */
    public long getAllocatedTotal() {
        return runtime.totalMemory();
    }

    /**
     * <b>Current allocated free memory</b>: space immediately ready for new objects.
     * <p>
     * <i>Caution</i>: this is not the total free available memory,
     * the JVM may grow the heap for new allocations.
     */
    public long getAllocatedFree() {
        return runtime.freeMemory();
    }

    /**
     * <b>Used memory</b>:
     * Java heap currently used by instantiated objects. 
     * <p>
     * <i>Caution</i>: May include no longer referenced objects, soft references, etc.
     * that will be swept away by the next garbage collection.
     */
    public long getUsed() {
        return getAllocatedTotal() - getAllocatedFree();
    }

    /**
     * <b>Maximum allocation</b>: the process' allocated memory will not grow any further.
     * <p>
     * <i>Caution</i>: This may change over time, do not cache it!
     * There are some JVMs / garbage collectors that can shrink the allocated process memory.
     * <p>
     * <i>Caution</i>: If this is true, the JVM will likely run GC more often.
     */
    public boolean isAtMaximumAllocation() {
        return getAllocatedTotal() == getTotal();
        // = return getUnallocated() == 0;
    }

    /**
     * <b>Unallocated memory</b>: amount of space the process' heap can grow.
     */
    public long getUnallocated() {
        return getTotal() - getAllocatedTotal();
    }

    /**
     * <b>Total designated memory</b>: this will equal the configured {@code -Xmx} value.
     * <p>
     * <i>Caution</i>: You can never allocate more memory than this, unless you use native code.
     */
    public long getTotal() {
        return runtime.maxMemory();
    }

    /**
     * <b>Total free memory</b>: memory available for new Objects,
     * even at the cost of growing the allocated memory of the process.
     */
    public long getFree() {
        return getTotal() - getUsed();
        // = return getAllocatedFree() + getUnallocated();
    }

    /**
     * <b>Unbounded memory</b>: there is no inherent limit on free memory.
     */
    public boolean isBounded() {
        return getTotal() != Long.MAX_VALUE;
    }

    /**
     * Dump of the current state for debugging or understanding the memory divisions.
     * <p>
     * <i>Caution</i>: Numbers may not match up exactly as state may change during the call.
     */
    public String getCurrentStats() {
        StringWriter backing = new StringWriter();
        PrintWriter out = new PrintWriter(backing, false);
        out.printf("Total: allocated %,d (%.1f%%) out of possible %,d; %s, %s %,d%n",
                getAllocatedTotal(),
                (float)getAllocatedTotal() / (float)getTotal() * 100,
                getTotal(),
                isBounded()? "bounded" : "unbounded",
                isAtMaximumAllocation()? "maxed out" : "can grow",
                getUnallocated()
        );
        out.printf("Used: %,d; %.1f%% of total (%,d); %.1f%% of allocated (%,d)%n",
                getUsed(),
                (float)getUsed() / (float)getTotal() * 100,
                getTotal(),
                (float)getUsed() / (float)getAllocatedTotal() * 100,
                getAllocatedTotal()
        );
        out.printf("Free: %,d (%.1f%%) out of %,d total; %,d (%.1f%%) out of %,d allocated%n",
                getFree(),
                (float)getFree() / (float)getTotal() * 100,
                getTotal(),
                getAllocatedFree(),
                (float)getAllocatedFree() / (float)getAllocatedTotal() * 100,
                getAllocatedTotal()
        );
        out.flush();
        return backing.toString();
    }

    public static void main(String... args) {
        SystemMemory memory = new SystemMemory();
        System.out.println(memory.getCurrentStats());
    }
}

What is JAVA_HOME? How does the JVM find the javac path stored in JAVA_HOME?

JAVA_HOME and JRE_HOME are not used by Java itself. Some third-party programs (for example Apache Tomcat) expect one of these environment variables to be set to the installation directory of the JDK or JRE. If you are not using software that requires them, you do not need to set JAVA_HOME and JRE_HOME. PATH is an environment variable used by the operating system (Windows, Mac OS X, Linux) where it will look for native executable programs to run. You should add the bin subdirectory of your JDK installation directory to the PATH, so that you can use the javac and java commands and other JDK tools in a command prompt window. Courtesy: coderanch

How often does python flush to a file?

For file operations, Python uses the operating system's default buffering unless you configure it do otherwise. You can specify a buffer size, unbuffered, or line buffered.

For example, the open function takes a buffer size argument.

http://docs.python.org/library/functions.html#open

"The optional buffering argument specifies the file’s desired buffer size:"

  • 0 means unbuffered,
  • 1 means line buffered,
  • any other positive value means use a buffer of (approximately) that size.
  • A negative buffering means to use the system default, which is usually line buffered for tty devices and fully buffered for other files.
  • If omitted, the system default is used.

code:

bufsize = 0
f = open('file.txt', 'w', buffering=bufsize)

background: fixed no repeat not working on mobile

Fixed positioning is supported on mobile since Android 2.2 and iOS 5.

You need to use device-with viewport on meta and give the background image with somewhere with an id. Then you will get that id with jquery and give that a height. And of course 100% width

<html>
<head>
    <title></title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        #main {
          background: url(1.jpg) no-repeat center center fixed;
          -webkit-background-size: cover;
          -moz-background-size: cover;
          -o-background-size: cover;
          background-size: cover;
          width: 100%;
          overflow: hidden;
        }
    </style>
</head>
<body id="main">

<script src="https://code.jquery.com/jquery-2.1.1.min.js"></script>
<script>
    var hgt = $(window).height();
    $("#main").css("height", hgt)
</script> 

http://jsfiddle.net/talendil/oackpmv5/

add title attribute from css

Quentin is correct, it can't be done with CSS. If you want to add a title attribute, you can do it with JavaScript. Here's an example using jQuery:

$('label').attr('title','mandatory');

How do you list the primary key of a SQL Server table?

Is using MS SQL Server you can do the following:

--List all tables primary keys
select * from information_schema.table_constraints
where constraint_type = 'Primary Key'

You can also filter on the table_name column if you want a specific table.

How to write header row with csv.DictWriter?

Edit:
In 2.7 / 3.2 there is a new writeheader() method. Also, John Machin's answer provides a simpler method of writing the header row.
Simple example of using the writeheader() method now available in 2.7 / 3.2:

from collections import OrderedDict
ordered_fieldnames = OrderedDict([('field1',None),('field2',None)])
with open(outfile,'wb') as fou:
    dw = csv.DictWriter(fou, delimiter='\t', fieldnames=ordered_fieldnames)
    dw.writeheader()
    # continue on to write data

Instantiating DictWriter requires a fieldnames argument.
From the documentation:

The fieldnames parameter identifies the order in which values in the dictionary passed to the writerow() method are written to the csvfile.

Put another way: The Fieldnames argument is required because Python dicts are inherently unordered.
Below is an example of how you'd write the header and data to a file.
Note: with statement was added in 2.6. If using 2.5: from __future__ import with_statement

with open(infile,'rb') as fin:
    dr = csv.DictReader(fin, delimiter='\t')

# dr.fieldnames contains values from first row of `f`.
with open(outfile,'wb') as fou:
    dw = csv.DictWriter(fou, delimiter='\t', fieldnames=dr.fieldnames)
    headers = {} 
    for n in dw.fieldnames:
        headers[n] = n
    dw.writerow(headers)
    for row in dr:
        dw.writerow(row)

As @FM mentions in a comment, you can condense header-writing to a one-liner, e.g.:

with open(outfile,'wb') as fou:
    dw = csv.DictWriter(fou, delimiter='\t', fieldnames=dr.fieldnames)
    dw.writerow(dict((fn,fn) for fn in dr.fieldnames))
    for row in dr:
        dw.writerow(row)

How to set size for local image using knitr for markdown?

Here's some options that keep the file self-contained without retastering the image:

Wrap the image in div tags

<div style="width:300px; height:200px">
![Image](path/to/image)
</div>

Use a stylesheet

test.Rmd

---
title: test
output: html_document
css: test.css
---

## Page with an image {#myImagePage}

![Image](path/to/image)

test.css

#myImagePage img {
  width: 400px;
  height: 200px;
}

If you have more than one image you might need to use the nth-child pseudo-selector for this second option.

JavaScript: What are .extend and .prototype used for?

The extend method for example in jQuery or PrototypeJS, copies all properties from the source to the destination object.

Now about the prototype property, it is a member of function objects, it is part of the language core.

Any function can be used as a constructor, to create new object instances. All functions have this prototype property.

When you use the new operator with on a function object, a new object will be created, and it will inherit from its constructor prototype.

For example:

function Foo () {
}
Foo.prototype.bar = true;

var foo = new Foo();

foo.bar; // true
foo instanceof Foo; // true
Foo.prototype.isPrototypeOf(foo); // true

Cannot access a disposed object - How to fix?

If this happens sporadically then my guess is that it has something to do with the timer.

I'm guessing (and this is only a guess since I have no access to your code) that the timer is firing while the form is being closed. The dbiSchedule object has been disposed but the timer somehow still manages to try to call it. This shouldn't happen, because if the timer has a reference to the schedule object then the garbage collector should see this and not dispose of it.

This leads me to ask: are you calling Dispose() on the schedule object manually? If so, are you doing that before disposing of the timer? Be sure that you release all references to the schedule object before Disposing it (i.e. dispose of the timer beforehand).

Now I realize that a few months have passed between the time you posted this and when I am answering, so hopefully, you have resolved this issue. I'm writing this for the benefit of others who may come along later with a similar issue.

Hope this helps.

Use dynamic variable names in `dplyr`

Another alternative: use {} inside quotation marks to easily create dynamic names. This is similar to other solutions but not exactly the same, and I find it easier.

library(dplyr)
library(tibble)

iris <- as_tibble(iris)

multipetal <- function(df, n) {
  df <- mutate(df, "petal.{n}" := Petal.Width * n)  ## problem arises here
  df
}

for(i in 2:5) {
  iris <- multipetal(df=iris, n=i)
}
iris

I think this comes from dplyr 1.0.0 but not sure (I also have rlang 4.7.0 if it matters).

convert streamed buffers to utf8-string

Single Buffer

If you have a single Buffer you can use its toString method that will convert all or part of the binary contents to a string using a specific encoding. It defaults to utf8 if you don't provide a parameter, but I've explicitly set the encoding in this example.

var req = http.request(reqOptions, function(res) {
    ...

    res.on('data', function(chunk) {
        var textChunk = chunk.toString('utf8');
        // process utf8 text chunk
    });
});

Streamed Buffers

If you have streamed buffers like in the question above where the first byte of a multi-byte UTF8-character may be contained in the first Buffer (chunk) and the second byte in the second Buffer then you should use a StringDecoder. :

var StringDecoder = require('string_decoder').StringDecoder;

var req = http.request(reqOptions, function(res) {
    ...
    var decoder = new StringDecoder('utf8');

    res.on('data', function(chunk) {
        var textChunk = decoder.write(chunk);
        // process utf8 text chunk
    });
});

This way bytes of incomplete characters are buffered by the StringDecoder until all required bytes were written to the decoder.

How to remove old Docker containers

Remove all containers created from a certain image:

docker rm  $(docker ps -a | awk '/myimage:mytag/{print $1}')

Confusion: @NotNull vs. @Column(nullable = false) with JPA and Hibernate

The JPA @Column Annotation

The nullable attribute of the @Column annotation has two purposes:

  • it's used by the schema generation tool
  • it's used by Hibernate during flushing the Persistence Context

Schema Generation Tool

The HBM2DDL schema generation tool translates the @Column(nullable = false) entity attribute to a NOT NULL constraint for the associated table column when generating the CREATE TABLE statement.

As I explained in the Hibernate User Guide, it's better to use a tool like Flyway instead of relying on the HBM2DDL mechanism for generating the database schema.

Persistence Context Flush

When flushing the Persistence Context, Hibernate ORM also uses the @Column(nullable = false) entity attribute:

new Nullability( session ).checkNullability( values, persister, true );

If the validation fails, Hibernate will throw a PropertyValueException, and prevents the INSERT or UPDATE statement to be executed needesly:

if ( !nullability[i] && value == null ) {
    //check basic level one nullablilty
    throw new PropertyValueException(
            "not-null property references a null or transient value",
            persister.getEntityName(),
            persister.getPropertyNames()[i]
        );    
}

The Bean Validation @NotNull Annotation

The @NotNull annotation is defined by Bean Validation and, just like Hibernate ORM is the most popular JPA implementation, the most popular Bean Validation implementation is the Hibernate Validator framework.

When using Hibernate Validator along with Hibernate ORM, Hibernate Validator will throw a ConstraintViolation when validating the entity.

Change Timezone in Lumen or Laravel 5

After changing app.php, make sure you run:

 php artisan config:clear

This is needed to clear the cache of config settings. If you notice that your timestamps are still wrong after changing the timezone in your app.php file, then running the above command should refresh everything, and your new timezone should be effective.

How to determine whether an object has a given property in JavaScript

Since question was regarding clunkiness of property checking, and one regular usecase for that being validation of function argument options objects, thought I'd mention a library-free short way of testing existence of multiple properties. Disclaimer: It does require ECMAScript 5 (but IMO anyone still using IE8 deserves a broken web).

function f(opts) {
  if(!["req1","req2"].every(opts.hasOwnProperty, opts)) {
      throw new Error("IllegalArgumentException");
  }
  alert("ok");
}
f({req1: 123});  // error
f({req1: 123, req2: 456});  // ok

How can I force a long string without any blank to be wrapped?

for block elements:

_x000D_
_x000D_
<textarea style="width:100px; word-wrap:break-word;">_x000D_
  ACTGATCGAGCTGAAGCGCAGTGCGATGCTTCGATGATGCTGACGATGCTACGATGCGAGCATCTACGATCAGTC_x000D_
</textarea>
_x000D_
_x000D_
_x000D_

for inline elements:

_x000D_
_x000D_
<span style="width:100px; word-wrap:break-word; display:inline-block;"> _x000D_
   ACTGATCGAGCTGAAGCGCAGTGCGATGCTTCGATGATGCTGACGATGCTACGATGCGAGCATCTACGATCAGTC_x000D_
</span>
_x000D_
_x000D_
_x000D_

How to transfer some data to another Fragment?

Complete code of passing data using fragment to fragment

Fragment fragment = new Fragment(); // replace your custom fragment class 
Bundle bundle = new Bundle();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
                bundle.putString("key","value"); // use as per your need
                fragment.setArguments(bundle);
                fragmentTransaction.addToBackStack(null);
                fragmentTransaction.replace(viewID,fragment);
                fragmentTransaction.commit();

In custom fragment class

Bundle mBundle = new Bundle();
mBundle = getArguments();
mBundle.getString(key);  // key must be same which was given in first fragment

How do I get PHP errors to display?

    <?php
    // Turn off error reporting
    error_reporting(0);

    // Report runtime errors
    error_reporting(E_ERROR | E_WARNING | E_PARSE);

    // Report all errors
    error_reporting(E_ALL);

    // Same as error_reporting(E_ALL);
    ini_set("error_reporting", E_ALL);

    // Report all errors except E_NOTICE
    error_reporting(E_ALL & ~E_NOTICE);
    ?>

While your site is live, the php.ini file should have display_errors disabled for security reasons. However, for the development environment, display_errors can be enabled for troubleshooting.

How to wait till the response comes from the $http request, in angularjs?

You should use promises for async operations where you don't know when it will be completed. A promise "represents an operation that hasn't completed yet, but is expected in the future." (https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Promise)

An example implementation would be like:

myApp.factory('myService', function($http) {

    var getData = function() {

        // Angular $http() and then() both return promises themselves 
        return $http({method:"GET", url:"/my/url"}).then(function(result){

            // What we return here is the data that will be accessible 
            // to us after the promise resolves
            return result.data;
        });
    };


    return { getData: getData };
});


function myFunction($scope, myService) {
    var myDataPromise = myService.getData();
    myDataPromise.then(function(result) {  

       // this is only run after getData() resolves
       $scope.data = result;
       console.log("data.name"+$scope.data.name);
    });
}

Edit: Regarding Sujoys comment that What do I need to do so that myFuction() call won't return till .then() function finishes execution.

function myFunction($scope, myService) { 
    var myDataPromise = myService.getData(); 
    myDataPromise.then(function(result) { 
         $scope.data = result; 
         console.log("data.name"+$scope.data.name); 
    }); 
    console.log("This will get printed before data.name inside then. And I don't want that."); 
 }

Well, let's suppose the call to getData() took 10 seconds to complete. If the function didn't return anything in that time, it would effectively become normal synchronous code and would hang the browser until it completed.

With the promise returning instantly though, the browser is free to continue on with other code in the meantime. Once the promise resolves/fails, the then() call is triggered. So it makes much more sense this way, even if it might make the flow of your code a bit more complex (complexity is a common problem of async/parallel programming in general after all!)

Is it possible to assign a base class object to a derived class reference with an explicit typecast?

You can use an Extention:

public static void CopyOnlyEqualProperties<T>(this T objDest, object objSource) where T : class
    {
        foreach (PropertyInfo propInfo in typeof(T).GetProperties())
            if (objSource.GetType().GetProperties().Any(z => z.Name == propInfo.Name && z.GetType() == propInfo.GetType()))
                propInfo.SetValue(objDest, objSource.GetType().GetProperties().First(z => z.Name == propInfo.Name && z.GetType() == propInfo.GetType()).GetValue(objSource));
    }

In Code:

public class BaseClass
{
  public string test{ get; set;}
}
public Derived : BaseClass
{
//Some properies
}

public void CopyProps()
{
   BaseClass baseCl =new BaseClass();
   baseCl.test="Hello";
   Derived drv=new Derived();
   drv.CopyOnlyEqualProperties(baseCl);
   //Should return Hello to the console now in derived class.
   Console.WriteLine(drv.test);

}

Android WSDL/SOAP service client

I’ve created a new SOAP client for the Android platform, it is use a JAX-WS generated interfaces, but it is only a proof-of-concept yet.

If you are interested, please try the example and/or watch the source: http://wiki.javaforum.hu/display/ANDROIDSOAP/Home

Update: the version 0.0.4 is out with tutorial:

http://wiki.javaforum.hu/display/ANDROIDSOAP/2012/04/16/Version+0.0.4+released

http://wiki.javaforum.hu/display/ANDROIDSOAP/Step+by+step+tutorial

How do you convert a jQuery object into a string?

With jQuery 1.6, this seems to be a more elegant solution:

$('#element-of-interest').prop('outerHTML');

How do I check for equality using Spark Dataframe without SQL Query?

Worked on Spark V2.*

import sqlContext.implicits._
df.filter($"state" === "TX")

if needs to be compared against a variable (e.g., var):

import sqlContext.implicits._
df.filter($"state" === var)

Note : import sqlContext.implicits._

PowerMockito mock single static method and return object

What you want to do is a combination of part of 1 and all of 2.

You need to use the PowerMockito.mockStatic to enable static mocking for all static methods of a class. This means make it possible to stub them using the when-thenReturn syntax.

But the 2-argument overload of mockStatic you are using supplies a default strategy for what Mockito/PowerMock should do when you call a method you haven't explicitly stubbed on the mock instance.

From the javadoc:

Creates class mock with a specified strategy for its answers to interactions. It's quite advanced feature and typically you don't need it to write decent tests. However it can be helpful when working with legacy systems. It is the default answer so it will be used only when you don't stub the method call.

The default default stubbing strategy is to just return null, 0 or false for object, number and boolean valued methods. By using the 2-arg overload, you're saying "No, no, no, by default use this Answer subclass' answer method to get a default value. It returns a Long, so if you have static methods which return something incompatible with Long, there is a problem.

Instead, use the 1-arg version of mockStatic to enable stubbing of static methods, then use when-thenReturn to specify what to do for a particular method. For example:

import static org.mockito.Mockito.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

class ClassWithStatics {
  public static String getString() {
    return "String";
  }

  public static int getInt() {
    return 1;
  }
}

@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassWithStatics.class)
public class StubJustOneStatic {
  @Test
  public void test() {
    PowerMockito.mockStatic(ClassWithStatics.class);

    when(ClassWithStatics.getString()).thenReturn("Hello!");

    System.out.println("String: " + ClassWithStatics.getString());
    System.out.println("Int: " + ClassWithStatics.getInt());
  }
}

The String-valued static method is stubbed to return "Hello!", while the int-valued static method uses the default stubbing, returning 0.

How to start activity in another application?

If you guys are facing "Permission Denial: starting Intent..." error or if the app is getting crash without any reason during launching the app - Then use this single line code in Manifest

android:exported="true"

Please be careful with finish(); , if you missed out it the app getting frozen. if its mentioned the app would be a smooth launcher.

finish();

The other solution only works for two activities that are in the same application. In my case, application B doesn't know class com.example.MyExampleActivity.class in the code, so compile will fail.

I searched on the web and found something like this below, and it works well.

Intent intent = new Intent();
intent.setComponent(new ComponentName("com.example", "com.example.MyExampleActivity"));
startActivity(intent);

You can also use the setClassName method:

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setClassName("com.hotfoot.rapid.adani.wheeler.android", "com.hotfoot.rapid.adani.wheeler.android.view.activities.MainActivity");
startActivity(intent);
finish();

You can also pass the values from one app to another app :

Intent launchIntent = getApplicationContext().getPackageManager().getLaunchIntentForPackage("com.hotfoot.rapid.adani.wheeler.android.LoginActivity");
if (launchIntent != null) {
    launchIntent.putExtra("AppID", "MY-CHILD-APP1");
    launchIntent.putExtra("UserID", "MY-APP");
    launchIntent.putExtra("Password", "MY-PASSWORD");
    startActivity(launchIntent);
    finish();
} else {
    Toast.makeText(getApplicationContext(), " launch Intent not available", Toast.LENGTH_SHORT).show();
}

PostgreSQL: export resulting data from SQL query to Excel/CSV

This worked for me:

COPY (SELECT * FROM table) 
    TO E'C:\\Program Files (x86)\\PostgreSQL\\8.4\\data\\try.csv';

In my case the problem was with the writing permission to a special folder (though I work as administrator), after changing the path to the original data folder under PostgreSQL I had success.

Parsing JSON array with PHP foreach

You maybe wanted to do the following:

foreach($user->data as $mydata)

    {
         echo $mydata->name . "\n";
         foreach($mydata->values as $values)
         {
              echo $values->value . "\n";
         }
    }        

Implementing a HashMap in C

Well if you know the basics behind them, it shouldn't be too hard.

Generally you create an array called "buckets" that contain the key and value, with an optional pointer to create a linked list.

When you access the hash table with a key, you process the key with a custom hash function which will return an integer. You then take the modulus of the result and that is the location of your array index or "bucket". Then you check the unhashed key with the stored key, and if it matches, then you found the right place.

Otherwise, you've had a "collision" and must crawl through the linked list and compare keys until you match. (note some implementations use a binary tree instead of linked list for collisions).

Check out this fast hash table implementation:

https://attractivechaos.wordpress.com/2009/09/29/khash-h/

Is it possible to use jQuery to read meta tags

For select twitter meta name , you can add a data attribute.

example :

meta name="twitter:card" data-twitterCard="" content=""
$('[data-twitterCard]').attr('content');

How to change an application icon programmatically in Android?

Programatically, you may want to publish the application launcher yourself :

Note: this method no longer works starting with Android 8.0 - Oreo

In your AndroidManifest.xml, add :

<uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT"/>

Then you need create your app launcher intent:

Intent myLauncherIntent = new Intent();
myLauncherIntent.setClassName("your.package.name", "YourLauncherActivityName");
myLauncherIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

Create an install shortcut intent with your app launcher and custom icon:

Intent intent = new Intent();
intent.putExtra(Intent.EXTRA_SHORTCUT_INTENT, myLauncherIntent);
intent.putExtra(Intent.EXTRA_SHORTCUT_NAME, "Application Name");
intent.putExtra
       (
        Intent.EXTRA_SHORTCUT_ICON_RESOURCE,
        Intent.ShortcutIconResource.fromContext
                                    (
                                         getApplicationContext(), 
                                         R.drawable.app_icon
                                    )
       );
intent.setAction("com.android.launcher.action.INSTALL_SHORTCUT");

And finally launch the broadcast intent:

getApplicationContext().sendBroadcast(intent);

How to clear a chart from a canvas so that hover events cannot be triggered?

If you are using chart.js in an Angular project with Typescript, the you can try the following;

Import the library:
    import { Chart } from 'chart.js';

In your Component Class declare the variable and define a method:

  chart: Chart;

  drawGraph(): void {
    if (this.chart) {
      this.chart.destroy();
    }

    this.chart = new Chart('myChart', {
       .........
    });
  }


In HTML Template:
<canvas id="myChart"></canvas>

C# Java HashMap equivalent

Use Dictionary - it uses hashtable but is typesafe.

Also, your Java code for

int a = map.get(key);
//continue with your logic

will be best coded in C# this way:

int a;
if(dict.TryGetValue(key, out a)){
//continue with your logic
}

This way, you can scope the need of variable "a" inside a block and it is still accessible outside the block if you need it later.

java: ArrayList - how can I check if an index exists?

Since java-9 there is a standard way of checking if an index belongs to the array - Objects#checkIndex() :

List<Integer> ints = List.of(1,2,3);
System.out.println(Objects.checkIndex(1,ints.size())); // 1
System.out.println(Objects.checkIndex(10,ints.size())); //IndexOutOfBoundsException

How to use Microsoft.Office.Interop.Excel on a machine without installed MS Office?

You can't use Microsoft.Office.Interop.Excel without having ms office installed.

Just search in google for some libraries, which allows to modify xls or xlsx:

No content to map due to end-of-input jackson parser

For one, @JsonProperty("status") and @JsonProperty("msg") should only be there only when declaring the fields, not on the setters and geters.

In fact, the simplest way to parse this would be

@JsonAutoDetect  //if you don't want to have getters and setters for each JsonProperty
public class StatusResponses {

   @JsonProperty("status")
   private String status;

   @JsonProperty("msg")
   private String message;

}

Excel formula to display ONLY month and year?

First thing first. set the column in which you are working in by clicking on format cells->number-> date and then format e.g Jan-16 representing Jan, 1, 2016. and then apply either of the formulas above.

How to set a bitmap from resource

If you have declare a bitmap object and you want to display it or store this bitmap object. but first you have to assign any image , and you may use the button click event, this code will only demonstrate that how to store the drawable image in bitmap Object.

Bitmap contact_pic = BitmapFactory.decodeResource(
                           v.getContext().getResources(),
                           R.drawable.android_logo
                     );

Now you can use this bitmap object, whether you want to store it, or to use it in google maps while drawing a pic on fixed latitude and longitude, or to use some where else

Confusing "duplicate identifier" Typescript error message

we removed a lib folder from the website folder. this was created by a previous installation of typings. this became duplicate. When this was removed it worked!

How to use if, else condition in jsf to display image

For those like I who just followed the code by skuntsel and received a cryptic stack trace, allow me to save you some time.

It seems c:if cannot by itself be followed by c:otherwise.

The correct solution is as follows:

<c:choose>
    <c:when test="#{some.test}">
        <p>some.test is true</p>
    </c:when>
    <c:otherwise>
        <p>some.test is not true</p>
    </c:otherwise>
</c:choose>

You can add additional c:when tests in as necessary.

Generic Property in C#

You just declare the property the normal way using a generic type:

public MyType<string> PropertyName { get; set; }

If you want to call predefined methods to do something in the get or set, implement the property getter/setter to call those methods.

Magento addFieldToFilter: Two fields, match as OR, not AND

Thanks Anda, your post has been a great help!! However the OR sentence didnt' quite work for me and I was getting an error: getCollection() "invalid argument supplied for foreach".

So this is what I ended with (notice the attribute being specified 3 times instead of 2 in this case):

  $collection->addFieldToFilter('attribute', array(  
    array('attribute'=>'my_field1','eq'=>'my_value1'),            
    array('attribute'=>'my_field2','eq'=>'my_value2') ));

addFieldToFilter first requires a field and then condition -> link.

T-SQL get SELECTed value of stored procedure

there are three ways you can use: the RETURN value, and OUTPUT parameter and a result set

ALSO, watch out if you use the pattern: SELECT @Variable=column FROM table ...

if there are multiple rows returned from the query, your @Variable will only contain the value from the last row returned by the query.

RETURN VALUE
since your query returns an int field, at least based on how you named it. you can use this trick:

CREATE PROCEDURE GetMyInt
( @Param int)
AS
DECLARE @ReturnValue int

SELECT @ReturnValue=MyIntField FROM MyTable WHERE MyPrimaryKeyField = @Param
RETURN @ReturnValue
GO

and now call your procedure like:

DECLARE @SelectedValue int
       ,@Param         int
SET @Param=1
EXEC @SelectedValue = GetMyInt @Param
PRINT @SelectedValue

this will only work for INTs, because RETURN can only return a single int value and nulls are converted to a zero.

OUTPUT PARAMETER
you can use an output parameter:

CREATE PROCEDURE GetMyInt
( @Param     int
 ,@OutValue  int OUTPUT)
AS
SELECT @OutValue=MyIntField FROM MyTable WHERE MyPrimaryKeyField = @Param
RETURN 0
GO

and now call your procedure like:

DECLARE @SelectedValue int
       ,@Param         int
SET @Param=1
EXEC GetMyInt @Param, @SelectedValue OUTPUT
PRINT @SelectedValue 

Output parameters can only return one value, but can be any data type

RESULT SET for a result set make the procedure like:

CREATE PROCEDURE GetMyInt
( @Param     int)
AS
SELECT MyIntField FROM MyTable WHERE MyPrimaryKeyField = @Param
RETURN 0
GO

use it like:

DECLARE @ResultSet table (SelectedValue int)
DECLARE @Param int
SET @Param=1
INSERT INTO @ResultSet (SelectedValue)
    EXEC GetMyInt @Param
SELECT * FROM @ResultSet 

result sets can have many rows and many columns of any data type

eval command in Bash and its typical uses

In the question:

who | grep $(tty | sed s:/dev/::)

outputs errors claiming that files a and tty do not exist. I understood this to mean that tty is not being interpreted before execution of grep, but instead that bash passed tty as a parameter to grep, which interpreted it as a file name.

There is also a situation of nested redirection, which should be handled by matched parentheses which should specify a child process, but bash is primitively a word separator, creating parameters to be sent to a program, therefore parentheses are not matched first, but interpreted as seen.

I got specific with grep, and specified the file as a parameter instead of using a pipe. I also simplified the base command, passing output from a command as a file, so that i/o piping would not be nested:

grep $(tty | sed s:/dev/::) <(who)

works well.

who | grep $(echo pts/3)

is not really desired, but eliminates the nested pipe and also works well.

In conclusion, bash does not seem to like nested pipping. It is important to understand that bash is not a new-wave program written in a recursive manner. Instead, bash is an old 1,2,3 program, which has been appended with features. For purposes of assuring backward compatibility, the initial manner of interpretation has never been modified. If bash was rewritten to first match parentheses, how many bugs would be introduced into how many bash programs? Many programmers love to be cryptic.

Get current time in seconds since the Epoch on Linux, Bash

This is an extension to what @pellucide has done, but for Macs:

To determine the number of seconds since epoch (Jan 1 1970) for any given date (e.g. Oct 21 1973)

$ date -j -f "%b %d %Y %T" "Oct 21 1973 00:00:00" "+%s"
120034800

Please note, that for completeness, I have added the time part to the format. The reason being is that date will take whatever date part you gave it and add the current time to the value provided. For example, if you execute the above command at 4:19PM, without the '00:00:00' part, it will add the time automatically. Such that "Oct 21 1973" will be parsed as "Oct 21 1973 16:19:00". That may not be what you want.

To convert your timestamp back to a date:

$ date -j -r 120034800
Sun Oct 21 00:00:00 PDT 1973

Apple's man page for the date implementation: https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/date.1.html

catching stdout in realtime from subprocess

On Linux, I had the same problem of getting rid of the buffering. I finally used "stdbuf -o0" (or, unbuffer from expect) to get rid of the PIPE buffering.

proc = Popen(['stdbuf', '-o0'] + cmd, stdout=PIPE, stderr=PIPE)
stdout = proc.stdout

I could then use select.select on stdout.

See also https://unix.stackexchange.com/questions/25372/

How to delete columns in numpy.array

Removing Matrix columns that contain NaN. This is a lengthy answer, but hopefully easy to follow.

def column_to_vector(matrix, i):
    return [row[i] for row in matrix]
import numpy
def remove_NaN_columns(matrix):
    import scipy
    import math
    from numpy import column_stack, vstack

    columns = A.shape[1]
    #print("columns", columns)
    result = []
    skip_column = True
    for column in range(0, columns):
        vector = column_to_vector(A, column)
        skip_column = False
        for value in vector:
            # print(column, vector, value, math.isnan(value) )
            if math.isnan(value):
                skip_column = True
        if skip_column == False:
            result.append(vector)
    return column_stack(result)

### test it
A = vstack(([ float('NaN'), 2., 3., float('NaN')], [ 1., 2., 3., 9]))
print("A shape", A.shape, "\n", A)
B = remove_NaN_columns(A)
print("B shape", B.shape, "\n", B)

A shape (2, 4) 
 [[ nan   2.   3.  nan]
 [  1.   2.   3.   9.]]
B shape (2, 2) 
 [[ 2.  3.]
 [ 2.  3.]]

How to make Git "forget" about a file that was tracked but is now in .gitignore?

I think, that maybe git can't totally forget about file because of its conception (section "Snapshots, Not Differences").

This problem is absent, for example, when using CVS. CVS stores information as a list of file-based changes. Information for CVS is a set of files and the changes made to each file over time.

But in Git every time you commit, or save the state of your project, it basically takes a picture of what all your files look like at that moment and stores a reference to that snapshot. So, if you added file once, it will always be present in that snapshot.

These 2 articles were helpful for me:

git assume-unchanged vs skip-worktree and How to ignore changes in tracked files with Git

Basing on it I do the following, if file is already tracked:

git update-index --skip-worktree <file>

From this moment all local changes in this file will be ignored and will not go to remote. If file is changed on remote, conflict will occure, when git pull. Stash won't work. To resolve it, copy file content to the safe place and follow these steps:

git update-index --no-skip-worktree <file>
git stash
git pull 

File content will be replaced by the remote content. Paste your changes from safe place to file and perform again:

git update-index --skip-worktree <file>

If everyone, who works with project, will perform git update-index --skip-worktree <file>, problems with pull should be absent. This solution is OK for configurations files, when every developer has their own project configuration.

It is not very convenient to do this every time, when file has been changed on remote, but can protect it from overwriting by remote content.

Reload content in modal (twitter bootstrap)

You can force Modal to refresh the popup by adding this line at the end of the hide method of the Modal plugin (If you are using bootstrap-transition.js v2.1.1, it should be at line 836)

this.$element.removeData()

Or with an event listener

$('#modal').on('hidden', function() {
    $(this).data('modal').$element.removeData();
})

Markdown: continue numbered list

If you happen to be using the Ruby gem redcarpet to render Markdown, you may still have this problem.

You can escape the numbering, and redcarpet will happily ignore any special meaning:

1\. Some heading

text text
text text

text text

2\. Some other heading

blah blah

more blah blah

How to reference static assets within vue javascript

It works for me by using require syntax like this:

$('.eventSlick').slick({
    dots: true,
    slidesToShow: 3,
    slidesToScroll: 1,
    autoplay: false,
    autoplaySpeed: 2000,
    arrows: true,
    draggable: false,
    prevArrow: '<button type="button" data-role="none" class="slick-prev"><img src="' + require("@/assets/img/icon/Arrow_Left.svg")+'"></button>',

eclipse won't start - no java virtual machine was found

Some time this happens when your Java folder get updated.

Open Eclipse folder and search file eclipse.ini. Open the eclipse.ini file and check whether jre version is same as jre available in your java folder.

I faced same problem when my jre got changed from jre1.8.0_101 to jre1.8.0_111.

C:\Program Files\Java\jre1.8.0_101\bin to C:\Program Files\Java\jre1.8.0_111\bin

What's the difference between IFrame and Frame?

The only reasons I can think of are actually in the wiki article you referenced to mention a couple...

"The "Verified by Visa" system has drawn some criticism, since it is hard for users to differentiate between the legitimate Verified by Visa pop-up window or inline frame, and a fraudulent phishing site."

"as of 2008, most web browsers do not provide a simple way to check the security certificate for the contents of an iframe"

If you read the Criticism section in the article it details all the potential security flaws.

Otherwise the only difference is the fact that an IFrame is an inline frame and a Frame is part of a Frameset. Which means more layout problems than anything else!

Replace substring with another substring C++

I think all solutions will fail if the length of the replacing string is different from the length of the string to be replaced. (search for "abc" and replace by "xxxxxx") A general approach might be:

void replaceAll( string &s, const string &search, const string &replace ) {
    for( size_t pos = 0; ; pos += replace.length() ) {
        // Locate the substring to replace
        pos = s.find( search, pos );
        if( pos == string::npos ) break;
        // Replace by erasing and inserting
        s.erase( pos, search.length() );
        s.insert( pos, replace );
    }
}

How to pass parameters in GET requests with jQuery

Had the same problem where I specified data but the browser was sending requests to URL ending with [Object object].

You should have processData set to true.

processData: true, // You should comment this out if is false or set to true

Validate that a string is a positive integer

return ((parseInt(str, 10).toString() == str) && str.indexOf('-') === -1);

won't work if you give a string like '0001' though

python: iterate a specific range in a list

listOfStuff =([a,b], [c,d], [e,f], [f,g])

for item in listOfStuff[1:3]:
    print item

You have to iterate over a slice of your tuple. The 1 is the first element you need and 3 (actually 2+1) is the first element you don't need.

Elements in a list are numerated from 0:

listOfStuff =([a,b], [c,d], [e,f], [f,g])
               0      1      2      3

[1:3] takes elements 1 and 2.

React Js: Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

I also had the same issue when trying to fetch the data from "/src" folder. Moving the file into the "/public" solved the problem from.

Convert base64 png data to javascript file objects

Way 1: only works for dataURL, not for other types of url.

function dataURLtoFile(dataurl, filename) {
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
        bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while(n--){
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new File([u8arr], filename, {type:mime});
}

//Usage example:
var file = dataURLtoFile('data:image/png;base64,......', 'a.png');
console.log(file);

Way 2: works for any type of url, (http url, dataURL, blobURL, etc...)

//return a promise that resolves with a File instance
function urltoFile(url, filename, mimeType){
    mimeType = mimeType || (url.match(/^data:([^;]+);/)||'')[1];
    return (fetch(url)
        .then(function(res){return res.arrayBuffer();})
        .then(function(buf){return new File([buf], filename, {type:mimeType});})
    );
}

//Usage example:
urltoFile('data:image/png;base64,......', 'a.png')
.then(function(file){
    console.log(file);
})

Both works in Chrome and Firefox.

How do I conditionally add attributes to React components?

I think this may be useful for those who would like attribute's value to be a function:

import { RNCamera } from 'react-native-camera';
[...]

export default class MyView extends React.Component {

    _myFunction = (myObject) => {
        console.log(myObject.type); //
    }

    render() {

        var scannerProps = Platform.OS === 'ios' ? 
        {
            onBarCodeRead : this._myFunction
        } 
        : 
        { 
            // here you can add attribute(s) for other platforms
        }

        return (
            // it is just a part of code for MyView's layout
            <RNCamera 
                ref={ref => { this.camera = ref; }}
                style={{ flex: 1, justifyContent: 'flex-end', alignItems: 'center', }}
                type={RNCamera.Constants.Type.back}
                flashMode={RNCamera.Constants.FlashMode.on}
                {...scannerProps}
            />
        );
    }
}

posting hidden value

I'm not sure what you just did there, but from what I can tell this is what you're asking for:

bookingfacilities.php

<form action="successfulbooking.php" method="post">
    <input type="hidden" name="date" value="<?php echo $date; ?>">  
    <input type="submit" value="Submit Form">
</form>

successfulbooking.php

<?php
    $date = $_POST['date'];
    // add code here
?>

Not sure what you want to do with that third page(booking_now.php) too.

How to write a multidimensional array to a text file?

If you don't need a human-readable output, another option you could try is to save the array as a MATLAB .mat file, which is a structured array. I despise MATLAB, but the fact that I can both read and write a .mat in very few lines is convenient.

Unlike Joe Kington's answer, the benefit of this is that you don't need to know the original shape of the data in the .mat file, i.e. no need to reshape upon reading in. And, unlike using pickle, a .mat file can be read by MATLAB, and probably some other programs/languages as well.

Here is an example:

import numpy as np
import scipy.io

# Some test data
x = np.arange(200).reshape((4,5,10))

# Specify the filename of the .mat file
matfile = 'test_mat.mat'

# Write the array to the mat file. For this to work, the array must be the value
# corresponding to a key name of your choice in a dictionary
scipy.io.savemat(matfile, mdict={'out': x}, oned_as='row')

# For the above line, I specified the kwarg oned_as since python (2.7 with 
# numpy 1.6.1) throws a FutureWarning.  Here, this isn't really necessary 
# since oned_as is a kwarg for dealing with 1-D arrays.

# Now load in the data from the .mat that was just saved
matdata = scipy.io.loadmat(matfile)

# And just to check if the data is the same:
assert np.all(x == matdata['out'])

If you forget the key that the array is named in the .mat file, you can always do:

print matdata.keys()

And of course you can store many arrays using many more keys.

So yes – it won't be readable with your eyes, but only takes 2 lines to write and read the data, which I think is a fair trade-off.

Take a look at the docs for scipy.io.savemat and scipy.io.loadmat and also this tutorial page: scipy.io File IO Tutorial

Alternative to iFrames with HTML5

If you want to do this and control the server from which the base page or content is being served, you can use Cross Origin Resource Sharing (http://www.w3.org/TR/access-control/) to allow client-side JavaScript to load data into a <div> via XMLHttpRequest():

// I safely ignore IE 6 and 5 (!) users
// because I do not wish to proliferate
// broken software that will hurt other
// users of the internet, which is what
// you're doing when you write anything
// for old version of IE (5/6)
xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
  if(xhr.readyState == 4 && xhr.status == 200) {
    document.getElementById('displayDiv').innerHTML = xhr.responseText;
  }
};
xhr.open('GET', 'http://api.google.com/thing?request=data', true);
xhr.send();

Now for the lynchpin of this whole operation, you need to write code for your server that will give clients the Access-Control-Allow-Origin header, specifying which domains you want the client-side code to be able to access via XMLHttpRequest(). The following is an example of PHP code you can include at the top of your page in order to send these headers to clients:

<?php
  header('Access-Control-Allow-Origin: http://api.google.com');
  header('Access-Control-Allow-Origin: http://some.example.com');
?>

Break promise chain and call a function based on the step in the chain where it is broken (rejected)

Try ro use this like libs:

https://www.npmjs.com/package/promise-chain-break

    db.getData()
.then(pb((data) => {
    if (!data.someCheck()) {
        tellSomeone();

        // All other '.then' calls will be skiped
        return pb.BREAK;
    }
}))
.then(pb(() => {
}))
.then(pb(() => {
}))
.catch((error) => {
    console.error(error);
});

How To fix white screen on app Start up?

enter image description here

Like you tube.. initially they show icon screen instead of white screen. And after 2 seconds shows home screen.

first create an XML drawable in res/drawable.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:drawable="@color/gray"/>

    <item>
        <bitmap
            android:gravity="center"
            android:src="@mipmap/ic_launcher"/>
    </item>

</layer-list>

Next, you will set this as your splash activity’s background in the theme. Navigate to your styles.xml file and add a new theme for your splash activity

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
    </style>

    <style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">
        <item name="android:windowBackground">@drawable/background_splash</item>
    </style>

</resources>

In your new SplashTheme, set the window background attribute to your XML drawable. Configure this as your splash activity’s theme in your AndroidManifest.xml:

<activity
    android:name=".SplashActivity"
    android:theme="@style/SplashTheme">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

This link gives what you want. step by step procedure. https://www.bignerdranch.com/blog/splash-screens-the-right-way/

UPDATE:

The layer-list can be even simpler like this (which also accepts vector drawables for the centered logo, unlike the <bitmap> tag):

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- Background color -->
    <item android:drawable="@color/gray"/>

    <!-- Logo at the center of the screen -->
    <item
        android:drawable="@mipmap/ic_launcher"
        android:gravity="center"/>
</layer-list>

How can I install an older version of a package via NuGet?

As of NuGet 2.8, there is a feature to downgrade a package.

NuGet 2.8 Release Notes

Example:

The following command entered into the Package Manager Console will downgrade the Couchbase client to version 1.3.1.0.

Update-Package CouchbaseNetClient -Version 1.3.1.0

Result:

Updating 'CouchbaseNetClient' from version '1.3.3' to '1.3.1.0' in project [project name].
Removing 'CouchbaseNetClient 1.3.3' from [project name].
Successfully removed 'CouchbaseNetClient 1.3.3' from [project name].

Something to note as per crimbo below:

This approach doesn't work for downgrading from one prerelease version to other prerelease version - it only works for downgrading to a release version

javascript push multidimensional array

Use []:

cookie_value_add.push([productID,itemColorTitle, itemColorPath]);

or

arrayToPush.push([value1, value2, ..., valueN]);

How do you select a particular option in a SELECT element in jQuery?

Exactly it will work try this below methods

For normal select option

<script>    
    $(document).ready(function() {
    $("#id").val('select value here');
       });
        </script>

For select 2 option trigger option need to use

<script>    
        $(document).ready(function() {
        $("#id").val('select value here').trigger('change');
           });
            </script>

ip address validation in python using regex

The following will check whether an IP is valid or not: If the IP is within 0.0.0.0 to 255.255.255.255, then the output will be true, otherwise it will be false:

[0<=int(x)<256 for x in re.split('\.',re.match(r'^\d+\.\d+\.\d+\.\d+$',your_ip).group(0))].count(True)==4

Example:

your_ip = "10.10.10.10"
[0<=int(x)<256 for x in re.split('\.',re.match(r'^\d+\.\d+\.\d+\.\d+$',your_ip).group(0))].count(True)==4

Output:

>>> your_ip = "10.10.10.10"
>>> [0<=int(x)<256 for x in re.split('\.',re.match(r'^\d+\.\d+\.\d+\.\d+$',your_ip).group(0))].count(True)==4
True
>>> your_ip = "10.10.10.256"
>>> [0<=int(x)<256 for x in re.split('\.',re.match(r'^\d+\.\d+\.\d+\.\d+$',your_ip).group(0))].count(True)==4
False
>>>

In Python, how do I determine if an object is iterable?

This isn't sufficient: the object returned by __iter__ must implement the iteration protocol (i.e. next method). See the relevant section in the documentation.

In Python, a good practice is to "try and see" instead of "checking".

Android disable screen timeout while app is running

Simple add below line into your MainActivity and your App never turn lights off.

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

How to change font of UIButton with Swift

You should go through the titleLabel property.

button.titleLabel.font

The font property has been deprecated since iOS 3.0.

Determine command line working directory when running node bin script

Here's what worked for me:

console.log(process.mainModule.filename);

Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code

Try the below:

  1. pod deintegrate
  2. pod install
  3. XCode Clean build

Or, One-Liner:

pod deintegrate; pod install

An existing connection was forcibly closed by the remote host

This error occurred in my application with the CIP-protocol whenever I didn't Send or received data in less than 10s.

This was caused by the use of the forward open method. You can avoid this by working with an other method, or to install an update rate of less the 10s that maintain your forward-open-connection.

How to Use Order By for Multiple Columns in Laravel 4?

You can do as @rmobis has specified in his answer, [Adding something more into it]

Using order by twice:

MyTable::orderBy('coloumn1', 'DESC')
    ->orderBy('coloumn2', 'ASC')
    ->get();

and the second way to do it is,

Using raw order by:

MyTable::orderByRaw("coloumn1 DESC, coloumn2 ASC");
    ->get();

Both will produce same query as follow,

SELECT * FROM `my_tables` ORDER BY `coloumn1` DESC, `coloumn2` ASC

As @rmobis specified in comment of first answer you can pass like an array to order by column like this,

$myTable->orders = array(
    array('column' => 'coloumn1', 'direction' => 'desc'), 
    array('column' => 'coloumn2', 'direction' => 'asc')
);

one more way to do it is iterate in loop,

$query = DB::table('my_tables');

foreach ($request->get('order_by_columns') as $column => $direction) {
    $query->orderBy($column, $direction);
}

$results = $query->get();

Hope it helps :)

How can I split a delimited string into an array in PHP?

explode has some very big problems in real life usage:

count(explode(',', null)); // 1 !! 
explode(',', null); // [""] not an empty array, but an array with one empty string!
explode(',', ""); // [""]
explode(',', "1,"); // ["1",""] ending commas are also unsupported, kinda like IE8

this is why i prefer preg_split

preg_split('@,@', $string, NULL, PREG_SPLIT_NO_EMPTY)

the entire boilerplate:

/** @brief wrapper for explode
 * @param string|int|array $val string will explode. '' return []. int return string in array (1 returns ['1']). array return itself. for other types - see $as_is
 * @param bool $as_is false (default): bool/null return []. true: bool/null return itself.
 * @param string $delimiter default ','
 * @return array|mixed
 */
public static function explode($val, $as_is = false, $delimiter = ',')
{
    // using preg_split (instead of explode) because it is the best way to handle ending comma and avoid empty string converted to ['']
    return (is_string($val) || is_int($val)) ?
        preg_split('@' . preg_quote($delimiter, '@') . '@', $val, NULL, PREG_SPLIT_NO_EMPTY)
        :
        ($as_is ? $val : (is_array($val) ? $val : []));
}

Android Shared preferences for creating one time activity (example)

Setting values in Preference:

// MY_PREFS_NAME - a static String variable like: 
//public static final String MY_PREFS_NAME = "MyPrefsFile";
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
 editor.putString("name", "Elena");
 editor.putInt("idName", 12);
 editor.apply();

Retrieve data from preference:

SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE); 
String name = prefs.getString("name", "No name defined");//"No name defined" is the default value.
int idName = prefs.getInt("idName", 0); //0 is the default value.

More info:

Using Shared Preferences

Shared Preferences

SQL LEFT JOIN Subquery Alias

I recognize that the answer works and has been accepted but there is a much cleaner way to write that query. Tested on mysql and postgres.

SELECT wpoi.order_id As No_Commande
FROM  wp_woocommerce_order_items AS wpoi
LEFT JOIN wp_postmeta AS wpp ON wpoi.order_id = wpp.post_id 
                            AND wpp.meta_key = '_shipping_first_name'
WHERE  wpoi.order_id =2198 

What is the difference between Jupyter Notebook and JupyterLab?

(I am using JupyterLab with Julia)

First thing is that Jupyter lab from my previous use offers more 'themes' which is great on the eyes, and also fontsize changes independent of the browser, so that makes it closer to that of an IDE. There are some specifics I like such as changing the 'code font size' and leaving the interface font size to be the same.

Major features that are great is

  • the drag and drop of cells so that you can easily rearrange the code
  • collapsing cells with a single mouse click and a small mark to remind of their placement

What is paramount though is the ability to have split views of the tabs and the terminal. If you use Emacs, then you probably enjoyed having multiple buffers with horizontal and vertical arrangements with one of them running a shell (terminal), and with jupyterlab this can be done, and the arrangement is made with drags and drops which in Emacs is typically done with sets of commands.

(I do not believe that there is a learning curve added to those that have not used the 'notebook' original version first. You can dive straight into this IDE experience)

Bootstrap close responsive menu "on click"

I really liked Jake Taylor's idea of doing it without additional JavaScript and taking advantage of Bootstrap's collapse toggle. I found you can fix the "flickering" issue present when the menu isn't in collapsed mode by modifying the data-target selector slightly to include the in class. So it looks like this:

<li><a href="#Products" data-toggle="collapse" data-target=".navbar-collapse.in">Products</a></li>

I didn't test it with nested dropdowns/menus, so YMMV.

Twitter Bootstrap dropdown menu

You must include jQuery in the project.

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

I didn't find any doc about this so I just opened a random code example from tutorialrepublic.com http://www.tutorialrepublic.com/twitter-bootstrap-tutorial/bootstrap-dropdowns.php

Hope this helps someone else.

Convert or extract TTC font to TTF - how to?

If you've got a Mac the easiest way to split those would be to use DfontSplitter, available at https://peter.upfold.org.uk/projects/dfontsplitter

The Windows version they provide doesn't work with ttc files.

getApplication() vs. getApplicationContext()

It seems to have to do with context wrapping. Most classes derived from Context are actually a ContextWrapper, which essentially delegates to another context, possibly with changes by the wrapper.

The context is a general abstraction that supports mocking and proxying. Since many contexts are bound to a limited-lifetime object such as an Activity, there needs to be a way to get a longer-lived context, for purposes such as registering for future notifications. That is achieved by Context.getApplicationContext(). A logical implementation is to return the global Application object, but nothing prevents a context implementation from returning a wrapper or proxy with a suitable lifetime instead.

Activities and services are more specifically associated with an Application object. The usefulness of this, I believe, is that you can create and register in the manifest a custom class derived from Application and be certain that Activity.getApplication() or Service.getApplication() will return that specific object of that specific type, which you can cast to your derived Application class and use for whatever custom purpose.

In other words, getApplication() is guaranteed to return an Application object, while getApplicationContext() is free to return a proxy instead.

What is the logic behind the "using" keyword in C++?

In C++11, the using keyword when used for type alias is identical to typedef.

7.1.3.2

A typedef-name can also be introduced by an alias-declaration. The identifier following the using keyword becomes a typedef-name and the optional attribute-specifier-seq following the identifier appertains to that typedef-name. It has the same semantics as if it were introduced by the typedef specifier. In particular, it does not define a new type and it shall not appear in the type-id.

Bjarne Stroustrup provides a practical example:

typedef void (*PFD)(double);    // C style typedef to make `PFD` a pointer to a function returning void and accepting double
using PF = void (*)(double);    // `using`-based equivalent of the typedef above
using P = [](double)->void; // using plus suffix return type, syntax error
using P = auto(double)->void // Fixed thanks to DyP

Pre-C++11, the using keyword can bring member functions into scope. In C++11, you can now do this for constructors (another Bjarne Stroustrup example):

class Derived : public Base { 
public: 
    using Base::f;    // lift Base's f into Derived's scope -- works in C++98
    void f(char);     // provide a new f 
    void f(int);      // prefer this f to Base::f(int) 

    using Base::Base; // lift Base constructors Derived's scope -- C++11 only
    Derived(char);    // provide a new constructor 
    Derived(int);     // prefer this constructor to Base::Base(int) 
    // ...
}; 

Ben Voight provides a pretty good reason behind the rationale of not introducing a new keyword or new syntax. The standard wants to avoid breaking old code as much as possible. This is why in proposal documents you will see sections like Impact on the Standard, Design decisions, and how they might affect older code. There are situations when a proposal seems like a really good idea but might not have traction because it would be too difficult to implement, too confusing, or would contradict old code.


Here is an old paper from 2003 n1449. The rationale seems to be related to templates. Warning: there may be typos due to copying over from PDF.

First let’s consider a toy example:

template <typename T>
class MyAlloc {/*...*/};

template <typename T, class A>
class MyVector {/*...*/};

template <typename T>

struct Vec {
typedef MyVector<T, MyAlloc<T> > type;
};
Vec<int>::type p; // sample usage

The fundamental problem with this idiom, and the main motivating fact for this proposal, is that the idiom causes the template parameters to appear in non-deducible context. That is, it will not be possible to call the function foo below without explicitly specifying template arguments.

template <typename T> void foo (Vec<T>::type&);

So, the syntax is somewhat ugly. We would rather avoid the nested ::type We’d prefer something like the following:

template <typename T>
using Vec = MyVector<T, MyAlloc<T> >; //defined in section 2 below
Vec<int> p; // sample usage

Note that we specifically avoid the term “typedef template” and introduce the new syntax involving the pair “using” and “=” to help avoid confusion: we are not defining any types here, we are introducing a synonym (i.e. alias) for an abstraction of a type-id (i.e. type expression) involving template parameters. If the template parameters are used in deducible contexts in the type expression then whenever the template alias is used to form a template-id, the values of the corresponding template parameters can be deduced – more on this will follow. In any case, it is now possible to write generic functions which operate on Vec<T> in deducible context, and the syntax is improved as well. For example we could rewrite foo as:

template <typename T> void foo (Vec<T>&);

We underscore here that one of the primary reasons for proposing template aliases was so that argument deduction and the call to foo(p) will succeed.


The follow-up paper n1489 explains why using instead of using typedef:

It has been suggested to (re)use the keyword typedef — as done in the paper [4] — to introduce template aliases:

template<class T> 
    typedef std::vector<T, MyAllocator<T> > Vec;

That notation has the advantage of using a keyword already known to introduce a type alias. However, it also displays several disavantages among which the confusion of using a keyword known to introduce an alias for a type-name in a context where the alias does not designate a type, but a template; Vec is not an alias for a type, and should not be taken for a typedef-name. The name Vec is a name for the family std::vector< [bullet] , MyAllocator< [bullet] > > – where the bullet is a placeholder for a type-name. Consequently we do not propose the “typedef” syntax. On the other hand the sentence

template<class T>
    using Vec = std::vector<T, MyAllocator<T> >;

can be read/interpreted as: from now on, I’ll be using Vec<T> as a synonym for std::vector<T, MyAllocator<T> >. With that reading, the new syntax for aliasing seems reasonably logical.

I think the important distinction is made here, aliases instead of types. Another quote from the same document:

An alias-declaration is a declaration, and not a definition. An alias- declaration introduces a name into a declarative region as an alias for the type designated by the right-hand-side of the declaration. The core of this proposal concerns itself with type name aliases, but the notation can obviously be generalized to provide alternate spellings of namespace-aliasing or naming set of overloaded functions (see ? 2.3 for further discussion). [My note: That section discusses what that syntax can look like and reasons why it isn't part of the proposal.] It may be noted that the grammar production alias-declaration is acceptable anywhere a typedef declaration or a namespace-alias-definition is acceptable.

Summary, for the role of using:

  • template aliases (or template typedefs, the former is preferred namewise)
  • namespace aliases (i.e., namespace PO = boost::program_options and using PO = ... equivalent)
  • the document says A typedef declaration can be viewed as a special case of non-template alias-declaration. It's an aesthetic change, and is considered identical in this case.
  • bringing something into scope (for example, namespace std into the global scope), member functions, inheriting constructors

It cannot be used for:

int i;
using r = i; // compile-error

Instead do:

using r = decltype(i);

Naming a set of overloads.

// bring cos into scope
using std::cos;

// invalid syntax
using std::cos(double);

// not allowed, instead use Bjarne Stroustrup function pointer alias example
using test = std::cos(double);

How to convert NSNumber to NSString

or try NSString *string = [NSString stringWithFormat:@"%d", [NSNumber intValue], nil];

Alter column in SQL Server

To set a default value to a column, try this:

ALTER TABLE tb_TableName
ALTER COLUMN Record_Status SET DEFAULT 'default value'

Enable CORS in Web API 2

Late reply for future reference. What was working for me was enabling it by nuget and then adding custom headers into web.config.

How to change XAMPP apache server port?

If the XAMPP server is running for the moment, stop XAMPP server.

Follow these steps to change the port number.

Open the file in following location.

[XAMPP Installation Folder]/apache/conf/httpd.conf

Open the httpd.conf file and search for the String:

Listen 80

This is the port number used by XAMMP.

Then search for the string ServerName and update the Port Number which you entered earlier for Listen

Now save and re-start XAMPP server.

AngularJS app.run() documentation?

Here's the calling order:

  1. app.config()
  2. app.run()
  3. directive's compile functions (if they are found in the dom)
  4. app.controller()
  5. directive's link functions (again, if found)

Here's a simple demo where you can watch each one executing (and experiment if you'd like).

From Angular's module docs:

Run blocks - get executed after the injector is created and are used to kickstart the application. Only instances and constants can be injected into run blocks. This is to prevent further system configuration during application run time.

Run blocks are the closest thing in Angular to the main method. A run block is the code which needs to run to kickstart the application. It is executed after all of the services have been configured and the injector has been created. Run blocks typically contain code which is hard to unit-test, and for this reason should be declared in isolated modules, so that they can be ignored in the unit-tests.

One situation where run blocks are used is during authentications.

How to generate a random string of a fixed length in Go?

how random count in :

count, one := big.NewInt(0), big.NewInt(1)
count.SetString("100000000000000000000000", 10)

Finding square root without using sqrt function?

This a very simple recursive approach.

double mySqrt(double v, double test) {
    if (abs(test * test - v) < 0.0001) {
        return test;
    }

    double highOrLow = v / test;
    return mySqrt(v, (test + highOrLow) / 2.0);
}
double mySqrt(double v) {
    return mySqrt(v, v/2.0);
}

How can I tell how many objects I've stored in an S3 bucket?

Using AWS CLI

aws s3 ls s3://mybucket/ --recursive | wc -l 

or

aws cloudwatch get-metric-statistics \
  --namespace AWS/S3 --metric-name NumberOfObjects \
  --dimensions Name=BucketName,Value=BUCKETNAME \
              Name=StorageType,Value=AllStorageTypes \
  --start-time 2016-11-05T00:00 --end-time 2016-11-05T00:10 \
  --period 60 --statistic Average

Note: The above cloudwatch command seems to work for some while not for others. Discussed here: https://forums.aws.amazon.com/thread.jspa?threadID=217050

Using AWS Web Console

You can look at cloudwatch's metric section to get approx number of objects stored. enter image description here

I have approx 50 Million products and it took more than an hour to count using aws s3 ls

Add CSS to <head> with JavaScript?

As you are trying to add a string of CSS to <head> with JavaScript? injecting a string of CSS into a page it is easier to do this with the <link> element than the <style> element.

The following adds p { color: green; } rule to the page.

<link rel="stylesheet" type="text/css" href="data:text/css;charset=UTF-8,p%20%7B%20color%3A%20green%3B%20%7D" />

You can create this in JavaScript simply by URL encoding your string of CSS and adding it the HREF attribute. Much simpler than all the quirks of <style> elements or directly accessing stylesheets.

var linkElement = this.document.createElement('link');
linkElement.setAttribute('rel', 'stylesheet');
linkElement.setAttribute('type', 'text/css');
linkElement.setAttribute('href', 'data:text/css;charset=UTF-8,' + encodeURIComponent(myStringOfstyles));

This will work in IE 5.5 upwards

The solution you have marked will work but this solution requires fewer dom operations and only a single element.

Fastest way to check a string contain another substring in JavaScript?

I've found that using a simple for loop, iterating over all elements in the string and comparing using charAt performs faster than indexOf or Regex. The code and proof is available at JSPerf.

ETA: indexOf and charAt both perform similarly terrible on Chrome Mobile according to Browser Scope data listed on jsperf.com

What is the meaning of "int(a[::-1])" in Python?

Assuming a is a string. The Slice notation in python has the syntax -

list[<start>:<stop>:<step>]

So, when you do a[::-1], it starts from the end towards the first taking each element. So it reverses a. This is applicable for lists/tuples as well.

Example -

>>> a = '1234'
>>> a[::-1]
'4321'

Then you convert it to int and then back to string (Though not sure why you do that) , that just gives you back the string.

python "TypeError: 'numpy.float64' object cannot be interpreted as an integer"

Similar situation. It was working. Then, I started to include pytables. At first view, no reason to errors. I decided to use another function, that has a domain constraint (elipse) and received the following error:

TypeError: 'numpy.float64' object cannot be interpreted as an integer

or

TypeError: 'numpy.float64' object is not iterable

The crazy thing: the previous function I was using, no code changed, started to return the same error. My intermediary function, already used was:

def MinMax(x, mini=0, maxi=1)
    return max(min(x,mini), maxi)

The solution was avoid numpy or math:

def MinMax(x, mini=0, maxi=1)
    x = [x_aux if x_aux > mini else mini for x_aux in x]
    x = [x_aux if x_aux < maxi else maxi for x_aux in x]
    return max(min(x,mini), maxi)

Then, everything calm again. It was like one library possessed max and min!

Undefined class constant 'MYSQL_ATTR_INIT_COMMAND' with pdo

I got the same error, on debian6, when I had not yet installed php5-mysql.

So I installed it, then restarted apache2

apt-get install php5-mysql
/etc/init.d/apache2 restart

Then the error went away.

If you have the same error on Ubuntu, instead of:

/etc/init.d/apache2 restart  

Type:

service apache2 restart

MVC 5 Access Claims Identity User Data

I make my own extended class to see what I need, so when I need into my controller or my View, I only add the using to my namespace something like this:

public static class UserExtended
{
    public static string GetFullName(this IPrincipal user)
    {
        var claim = ((ClaimsIdentity)user.Identity).FindFirst(ClaimTypes.Name);
        return claim == null ? null : claim.Value;
    }
    public static string GetAddress(this IPrincipal user)
    {
        var claim = ((ClaimsIdentity)user.Identity).FindFirst(ClaimTypes.StreetAddress);
        return claim == null ? null : claim.Value;
    }
    public ....
    {
      .....
    }
}

In my controller:

using XXX.CodeHelpers.Extended;

var claimAddress = User.GetAddress();

In my razor:

@using DinexWebSeller.CodeHelpers.Extended;

@User.GetFullName()

Don't understand why UnboundLocalError occurs (closure)

The reason of why your code throws an UnboundLocalError is already well explained in other answers.

But it seems to me that you're trying to build something that works like itertools.count().

So why don't you try it out, and see if it suits your case:

>>> from itertools import count
>>> counter = count(0)
>>> counter
count(0)
>>> next(counter)
0
>>> counter
count(1)
>>> next(counter)
1
>>> counter
count(2)

How do I discard unstaged changes in Git?

No matter what state your repo is in you can always reset to any previous commit:

git reset --hard <commit hash>

This will discard all changes which were made after that commit.

How to to send mail using gmail in Laravel?

Using a G Suite account

If you are using a G Suite account, anything you try will fail. At least at the time, this answer is being typed. You must use @gmail.com account, anything else like @example.com will not work.

After you use the gmail.com address. You just need to update .env as most of the people already mentioned.

MAIL_MAILER=smtp
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
MAIL_USERNAME=****@gmail.com
MAIL_PASSWORD=16digitapppassword
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS=****@gmail.com
MAIL_FROM_NAME="${APP_NAME}"

Don't forget to create an App password, if you don't see the option probably your 2-factor authentication is not enabled. And there is no need to allow less secure apps if you follow this approach.

Android Studio: Default project directory

At some point I too tried to do this, but the Android Studio doesn’t work quite like Eclipse does.

It's simpler: if you create a project at, say /home/USER/Projects/AndroidStudio/MyApplication from there on all new projects will default to /home/USER/Projects/AndroidStudio.

You can also edit ~/.AndroidStudioPreview/config/options/ide.general.xml (in linux) and change the line that reads <option name="lastProjectLocation" value="$USER_HOME$/AndroidStudioProjects" /> to <option name="lastProjectLocation" value="$USER_HOME$/Projects/AndroidStudio" />, but be aware that as soon as you create a project anywhere else this will change to that place and all new projects will default to it.

Hope this helps, but the truth is there really isn't much more to it other than what I explained here.

Let me know if you need anything else.

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

This uses the above ideas but makes it a derived 'more sensitive' collection:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Collections;

namespace somethingelse
{
    public class ObservableCollectionEx<T> : ObservableCollection<T> where T : INotifyPropertyChanged
    {
        // this collection also reacts to changes in its components' properties

        public ObservableCollectionEx() : base()
        {
            this.CollectionChanged +=new System.Collections.Specialized.NotifyCollectionChangedEventHandler(ObservableCollectionEx_CollectionChanged);
        }

        void ObservableCollectionEx_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
        {
            if (e.Action == NotifyCollectionChangedAction.Remove)
            {
                foreach(T item in e.OldItems)
                {
                    //Removed items
                    item.PropertyChanged -= EntityViewModelPropertyChanged;
                }
            }
            else if (e.Action == NotifyCollectionChangedAction.Add)
            {
                foreach(T item in e.NewItems)
                {
                    //Added items
                    item.PropertyChanged += EntityViewModelPropertyChanged;
                }     
            }       
        }

        public void EntityViewModelPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            //This will get called when the property of an object inside the collection changes - note you must make it a 'reset' - I don't know, why
            NotifyCollectionChangedEventArgs args = new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset);
            OnCollectionChanged(args);
        }
    }
}

How to detect installed version of MS-Office?

If you've installed 32-bit Office on a 64-bit machine, you may need to check for the presence of "SOFTWARE\Wow6432Node\Microsoft\Office\12.0\", substituting the 12.0 with the appropriate version. This is certainly the case for Office 2007 installed on 64-bit Windows 7.

Note that Office 2010 (== 14.0) is the first Office for which a 64-bit version exists.

How to stop a function

A simple return statement will 'stop' or return the function; in precise terms, it 'returns' function execution to the point at which the function was called - the function is terminated without further action.

That means you could have a number of places throughout your function where it might return. Like this:

def player():
    # do something here
    check_winner_variable = check_winner()  # check something 
    if check_winner_variable == '1': 
        return
    second_test_variable = second_test()
    if second_test_variable == '1': 
        return
       
    # let the computer do something
    computer()

How to read a file in reverse order?

a simple function to create a second file reversed (linux only):

import os
def tac(file1, file2):
     print(os.system('tac %s > %s' % (file1,file2)))

how to use

tac('ordered.csv', 'reversed.csv')
f = open('reversed.csv')

Check if cookie exists else set cookie to Expire in 10 days

if (/(^|;)\s*visited=/.test(document.cookie)) {
    alert("Hello again!");
} else {
    document.cookie = "visited=true; max-age=" + 60 * 60 * 24 * 10; // 60 seconds to a minute, 60 minutes to an hour, 24 hours to a day, and 10 days.
    alert("This is your first time!");
}

is one way to do it. Note that document.cookie is a magic property, so you don't have to worry about overwriting anything, either.

There are also more convenient libraries to work with cookies, and if you don’t need the information you’re storing sent to the server on every request, HTML5’s localStorage and friends are convenient and useful.

Visual Studio Code cannot detect installed git

Update 2020 (Mac)

Went through this $h!† again after updating to Catalina, which requires an XCode update.

And to clarify, while this post is about VS Code, this issue, is system wide. Your git install is affected/hosed. You can try to run git in your terminal/bash/zsh or whatever it is now and it just won't.

Same fix, just update XCode, start it up and agree to license. That's it.


Old post, but just hit this on MAC/OSXso hope this helps someone.

Symptoms:

  • You've been using VS Code for some time and have no issues with Git
  • You install XCode (for whatever reason - OS update, etc)
  • After installing XCode, VS Code suddenly "can't find Git and asks you to either install or set the Path in settings"

Quick fix:

Run XCode (for the first time, after installing) and agree to license. That's it.

How I stumbled upon this "fix":

After going through numerous tips about checking git, e.g. which git and git --version, the latter actually offered clues with this Terminal message:

Agreeing to the Xcode/iOS license requires admin privileges, please run “sudo xcodebuild -license” and then retry this command.

As to why XCode would even wrap it's hands on git, WAT

Happy holidays and happy coding :)

Laravel 5.2 Missing required parameters for [Route: user.profile] [URI: user/{nickname}/profile]

Route::group(['middleware' => 'web'], function () {
Route::auth();

Route::get('/', ['as' => 'home', 'uses' => 'BaseController@index']);

Route::group(['namespace' => 'User', 'prefix' => 'user'], function(){
    Route::get('{nickname}/settings', ['as' => 'user.settings', 'uses' => 'SettingsController@index']);
    Route::get('{nickname}/profile', ['as' => 'user.profile', 'uses' => 'ProfileController@index']);
});
});

Opening port 80 EC2 Amazon web services

For those of you using Centos (and perhaps other linux distibutions), you need to make sure that its FW (iptables) allows for port 80 or any other port you want.

See here on how to completely disable it (for testing purposes only!). And here for specific rules

Best way to handle multiple constructors in Java

I would do the following:

public class Book
{
    private final String title;
    private final String isbn;

    public Book(final String t, final String i)
    {
        if(t == null)
        {
            throw new IllegalArgumentException("t cannot be null");
        }

        if(i == null)
        {
            throw new IllegalArgumentException("i cannot be null");
        }

        title = t;
        isbn  = i;
    }
}

I am making the assumption here that:

1) the title will never change (hence title is final) 2) the isbn will never change (hence isbn is final) 3) that it is not valid to have a book without both a title and an isbn.

Consider a Student class:

public class Student
{
    private final StudentID id;
    private String firstName;
    private String lastName;

    public Student(final StudentID i,
                   final String    first,
                   final String    last)
    {
        if(i == null)
        {
            throw new IllegalArgumentException("i cannot be null"); 
        }

        if(first == null)
        {
            throw new IllegalArgumentException("first cannot be null"); 
        }

        if(last == null)
        {
            throw new IllegalArgumentException("last cannot be null"); 
        }

        id        = i;
        firstName = first;
        lastName  = last;
    }
}

There a Student must be created with an id, a first name, and a last name. The student ID can never change, but a persons last and first name can change (get married, changes name due to losing a bet, etc...).

When deciding what constrructors to have you really need to think about what makes sense to have. All to often people add set/get methods because they are taught to - but very often it is a bad idea.

Immutable classes are much better to have (that is classes with final variables) over mutable ones. This book: http://books.google.com/books?id=ZZOiqZQIbRMC&pg=PA97&sig=JgnunNhNb8MYDcx60Kq4IyHUC58#PPP1,M1 (Effective Java) has a good discussion on immutability. Look at items 12 and 13.

SQL TRUNCATE DATABASE ? How to TRUNCATE ALL TABLES

I use this script

EXEC sp_MSForEachTable ‘ALTER TABLE ? NOCHECK CONSTRAINT ALL’
EXEC sp_MSForEachTable ‘DELETE FROM ?’
EXEC sp_MSForEachTable ‘ALTER TABLE ? CHECK CONSTRAINT ALL’
GO

The best way to calculate the height in a binary search tree? (balancing an AVL-tree)

Here's where it gets confusing, the text states "If the balance factor of R is 1, it means the insertion occurred on the (external) right side of that node and a left rotation is needed". But from m understanding the text said (as I quoted) that if the balance factor was within [-1, 1] then there was no need for balancing?

R is the right-hand child of the current node N.

If balance(N) = +2, then you need a rotation of some sort. But which rotation to use? Well, it depends on balance(R): if balance(R) = +1 then you need a left-rotation on N; but if balance(R) = -1 then you will need a double-rotation of some sort.

Injection of autowired dependencies failed;

public class Organization {

    @Id
    @Column(name="org_id")
    @GeneratedValue
    private int id;

    @Column(name="org_name")
    private String name;

    @Column(name="org_office_address1")
    private String address1;

    @Column(name="org_office_addres2")
    private String address2;

    @Column(name="city")
    private String city;

    @Column(name="state")
    private String state;

    @Column(name="country")
    private String country;

    @JsonIgnore
    @OneToOne
    @JoinColumn(name="pkg_id")
    private int pkgId;

    public int getPkgId() {
        return pkgId;
    }

    public void setPkgId(int pkgId) {
        this.pkgId = pkgId;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    @Column(name="pincode")
    private String pincode;

    @OneToMany(mappedBy = "organization", cascade=CascadeType.ALL, fetch = FetchType.EAGER)
    private Set<OrganizationBranch> organizationBranch = new HashSet<OrganizationBranch>(0);

    @Column(name="status")
    private String status = "ACTIVE";

    @Column(name="project_id")
    private int redmineProjectId;

    public int getRedmineProjectId() {
        return redmineProjectId;
    }

    public void setRedmineProjectId(int redmineProjectId) {
        this.redmineProjectId = redmineProjectId;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public Set<OrganizationBranch> getOrganizationBranch() {
        return organizationBranch;
    }

    public void setOrganizationBranch(Set<OrganizationBranch> organizationBranch) {
        this.organizationBranch = organizationBranch;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress1() {
        return address1;
    }

    public void setAddress1(String address1) {
        this.address1 = address1;
    }

    public String getAddress2() {
        return address2;
    }

    public void setAddress2(String address2) {
        this.address2 = address2;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public String getPincode() {
        return pincode;
    }

    public void setPincode(String pincode) {
        this.pincode = pincode;
    }
}

You change the private int pkgId line in change datatype int to primitive class name or add annotation @autowired

How do I generate random numbers in Dart?

Use Dart Generators, that is used to produce a sequence of number or values.

 main(){ 
       print("Sequence Number");
       oddnum(10).forEach(print);
     }
    Iterable<int> oddnum(int num) sync*{
     int k=num;
     while(k>=0){
       if(k%2==1){
        yield k;
       }
      k--;
     } 
}

Angular: Can't find Promise, Map, Set and Iterator

I had similar issue where it was not recognizing Promise.resolve() method. I changed "target" value from ES5 to ES6 in tsconfig.json. That solved the problem.

Hope this helps.

How To Get The Current Year Using Vba

Try =Year(Now()) and format the cell as General.

How to get commit history for just one branch?

I know it's very late for this one... But here is a (not so simple) oneliner to get what you were looking for:

git show-branch --all 2>/dev/null | grep -E "\[$(git branch | grep -E '^\*' | awk '{ printf $2 }')" | tail -n+2 | sed -E "s/^[^\[]*?\[/[/"
  • We are listing commits with branch name and relative positions to actual branch states with git show-branch (sending the warnings to /dev/null).
  • Then we only keep those with our branch name inside the bracket with grep -E "\[$BRANCH_NAME".
  • Where actual $BRANCH_NAME is obtained with git branch | grep -E '^\*' | awk '{ printf $2 }' (the branch with a star, echoed without that star).
  • From our results, we remove the redundant line at the beginning with tail -n+2.
  • And then, we fianlly clean up the output by removing everything preceding [$BRANCH_NAME] with sed -E "s/^[^\[]*?\[/[/".

onMeasure custom view explanation

actually, your answer is not complete as the values also depend on the wrapping container. In case of relative or linear layouts, the values behave like this:

  • EXACTLY match_parent is EXACTLY + size of the parent
  • AT_MOST wrap_content results in an AT_MOST MeasureSpec
  • UNSPECIFIED never triggered

In case of an horizontal scroll view, your code will work.

How to get summary statistics by group

after 5 long years I'm sure not much attention is going to be received for this answer, But still to make all options complete, here is the one with data.table

library(data.table)
setDT(df)[ , list(mean_gr = mean(dt), sum_gr = sum(dt)) , by = .(group)]
#   group mean_gr sum_gr
#1:     A      61    244
#2:     B      66    396
#3:     C      68    408
#4:     D      61    488 

How to extract or unpack an .ab file (Android Backup file)

As per https://android.stackexchange.com/a/78183/239063 you can run a one line command in Linux to add in an appropriate tar header to extract it.

( printf "\x1f\x8b\x08\x00\x00\x00\x00\x00" ; tail -c +25 backup.ab ) | tar xfvz -

Replace backup.ab with the path to your file.

AttributeError: 'numpy.ndarray' object has no attribute 'append'

I got this error after change a loop in my program, let`s see:

for ...
  for ... 
     x_batch.append(one_hot(int_word, vocab_size))
     y_batch.append(one_hot(int_nb, vocab_size, value))
  ...
  ...
  if ...
        x_batch = np.asarray(x_batch)
        y_batch = np.asarray(y_batch)
...

In fact, I was reusing the variable and forgot to reset them inside the external loop, like the comment of John Lyon:

for ...
  x_batch = []
  y_batch = []
  for ... 
     x_batch.append(one_hot(int_word, vocab_size))
     y_batch.append(one_hot(int_nb, vocab_size, value))
  ...
  ...
  if ...
        x_batch = np.asarray(x_batch)
        y_batch = np.asarray(y_batch)
...

Then, check if you are using np.asarray() or something like that.

Jackson - How to process (deserialize) nested JSON?

I'm quite late to the party, but one approach is to use a static inner class to unwrap values:

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

class Scratch {
    private final String aString;
    private final String bString;
    private final String cString;
    private final static String jsonString;

    static {
        jsonString = "{\n" +
                "  \"wrap\" : {\n" +
                "    \"A\": \"foo\",\n" +
                "    \"B\": \"bar\",\n" +
                "    \"C\": \"baz\"\n" +
                "  }\n" +
                "}";
    }

    @JsonCreator
    Scratch(@JsonProperty("A") String aString,
            @JsonProperty("B") String bString,
            @JsonProperty("C") String cString) {
        this.aString = aString;
        this.bString = bString;
        this.cString = cString;
    }

    @Override
    public String toString() {
        return "Scratch{" +
                "aString='" + aString + '\'' +
                ", bString='" + bString + '\'' +
                ", cString='" + cString + '\'' +
                '}';
    }

    public static class JsonDeserializer {
        private final Scratch scratch;

        @JsonCreator
        public JsonDeserializer(@JsonProperty("wrap") Scratch scratch) {
            this.scratch = scratch;
        }

        public Scratch getScratch() {
            return scratch;
        }
    }

    public static void main(String[] args) throws JsonProcessingException {
        ObjectMapper objectMapper = new ObjectMapper();
        Scratch scratch = objectMapper.readValue(jsonString, Scratch.JsonDeserializer.class).getScratch();
        System.out.println(scratch.toString());
    }
}

However, it's probably easier to use objectMapper.configure(SerializationConfig.Feature.UNWRAP_ROOT_VALUE, true); in conjunction with @JsonRootName("aName"), as pointed out by pb2q

Change multiple files

@PaulR posted this as a comment, but people should view it as an answer (and this answer works best for my needs):

sed -i 's/abc/xyz/g' xa*

This will work for a moderate amount of files, probably on the order of tens, but probably not on the order of millions.

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

The only solution that worked for me

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

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

  1. Cleaning/Rebuilding

  2. Cleaning bin, obj folders

  3. Changing namespace

Setting up foreign keys in phpMyAdmin?

Newer versions of phpMyAdmin don't have the "Relation View" option anymore, in which case you'll have to execute a statement to achieve the same thing. For example

ALTER TABLE employees
    ADD CONSTRAINT fk_companyid FOREIGN KEY (companyid)
    REFERENCES companies (id)
    ON DELETE CASCADE;

In this example, if a row from companies is deleted, all employees with that companyid are also deleted.

Difference between a View's Padding and Margin

Sometimes you can achieve the same result by playing only with padding OR margin. Example :

Say View X contains view Y (aka : View Y is inside View X).

-View Y with Margin=30 OR View X with Padding=30 will achieve the same result: View Y will have an offset of 30.

Webdriver Unable to connect to host 127.0.0.1 on port 7055 after 45000 ms

I had the same issue with firefox 38.

After using following version dependencies, I could resolve the issue.

    <dependency>
        <groupId>org.seleniumhq.selenium</groupId>
        <artifactId>selenium-java</artifactId>
        <version>2.53.0</version>
    </dependency>

    <dependency>
        <groupId>org.seleniumhq.selenium</groupId>
        <artifactId>selenium-firefox-driver</artifactId>
        <version>2.53.0</version>
    </dependency> 

Hide text within HTML?

Not sure if this was what you were asking for, but I was personally trying to 'hide' some info in my html so that if someone inspected it, they would see the text in the source code.

It turns out that you can add ANY attribute, and so long as it isn't understood by the browser, it will just be left buried in the tag. My code was an easter egg: For people who couldn't afford to do the Makers Academy course, I basically encouraged them to inspect the element, where they would be given a secret URL where they could apply for a special, cut-price course (it's in haml, but it's the same idea in HTML):

.entry
        %h2 I can't afford to do the course... What should I do?
        %p{:url_you_should_visit => 'http://ronin.makersacademy.com'} Inspect and you shall find.

Or in html:

<p url_you_should_visit="http://ronin.makersacademy.com">Inspect and you shall find.</p>

Because 'url' is not a recognised html attribute, it makes no difference but is still discoverable. You could do the same with anything you wanted. You could have an attribute (in html) like:

<p thanks="Thanks to all the bloggers that helped me"> Some text </p>

And they'll be able to find your little easter egg if they want it... Hope that helps - it certainly helped me :)

Node.js res.setHeader('content-type', 'text/javascript'); pushing the response javascript as file download

You can directly set the content type like below:

res.writeHead(200, {'Content-Type': 'text/plain'});

For reference go through the nodejs Docs link.

Apache and IIS side by side (both listening to port 80) on windows2003

I see this is quite an old post, but came across this looking for an answer for this problem. After reading some of the answers they seem very long winded, so after about 5 mins I managed to solve the problem very simply as follows:

httpd.conf for Apache leave the listen port as 80 and 'Server Name' as FQDN/IP :80.

Now for IIS go to Administrative Services > IIS Manager > 'Sites' in the Left hand nav drop down > in the right window select the top line (default web site) then bindings on the right.

Now select http > edit and change to 81 and enter your local IP for the server/pc and in domain enter either your FQDN (www.domain.com) or external IP close.

Restart both servers ensure your ports are open on both router and firewall, done.

This sounds long winded but literally took 5 mins of playing about. works perfectly.

System: Windows 8, IIS 8, Apache 2.2

Apache won't run in xampp

Try stopping Apache and MySql and starting them again in the following order.

  1. Apache
  2. MySql
  3. Etc...

Wait for both services to stop properly before restarting. Turning them on and off too quickly gives the same problem.

Inspired by lansharks answer.

android: how to change layout on button click?

It is very simple, just do this:

t4.setOnClickListener(new OnClickListener(){

        @Override
        public void onClick(View v) {

            launchQuiz2();          // TODO Auto-generated method stub

        }

        private void launchQuiz2() {
            Intent i = new Intent(MainActivity.this, Quiz2.class);
            startActivity(i);
            // TODO Auto-generated method stub

        }

    });

Get absolute path of initially run script

echo realpath(dirname(__FILE__));

If you place this in an included file, it prints the path to this include. To get the path of the parent script, replace __FILE__ with $_SERVER['PHP_SELF']. But be aware that PHP_SELF is a security risk!

Clear the entire history stack and start a new activity on Android

Advanced Reuseable Kotlin:

You can set the flag directly using setter method. In Kotlin or is the replacement for the Java bitwise or |.

intent.flags = FLAG_ACTIVITY_NEW_TASK or FLAG_ACTIVITY_CLEAR_TASK

If you plan to use this regularly, create an Intent extension function

fun Intent.clearStack() {
    flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}

You can then directly call this function before starting the intent

intent.clearStack()

If you need the option to add additional flags in other situations, add an optional param to the extension function.

fun Intent.clearStack(additionalFlags: Int = 0) {
    flags = additionalFlags or Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}

MySQL Update Column +1?

update table_name set field1 = field1 + 1;

What is the meaning of "Failed building wheel for X" in pip install?

I would like to add that if you only have Python3 on your system then you need to start using pip3 instead of pip.

You can install pip3 using the following command;

sudo apt install python3-pip -y

After this you can try to install the package you need with;

sudo pip3 install <package>

What is the difference between min SDK version/target SDK version vs. compile SDK version?

The min sdk version is the minimum version of the Android operating system required to run your application.

The target sdk version is the version of Android that your app was created to run on.

The compile sdk version is the the version of Android that the build tools uses to compile and build the application in order to release, run, or debug.

Usually the compile sdk version and the target sdk version are the same.

TypeError: tuple indices must be integers, not str

I think you should do

for index, row in result: 

If you wanna access by name.

Updating an object with setState in React

try this,it should work fine

this.setState(Object.assign(this.state.jasper,{name:'someOtherName'}));

how to extract only the year from the date in sql server 2008?

year(table_column)

Example:

select * from mytable where year(transaction_day)='2013' 

How do I call REST API from an android app?

  1. If you want to integrate Retrofit (all steps defined here):

Goto my blog : retrofit with kotlin

  1. Please use android-async-http library.

the link below explains everything step by step.

http://loopj.com/android-async-http/

Here are sample apps:

  1. http://www.techrepublic.com/blog/software-engineer/calling-restful-services-from-your-android-app/

  2. http://blog.strikeiron.com/bid/73189/Integrate-a-REST-API-into-Android-Application-in-less-than-15-minutes

Create a class :

public class HttpUtils {
  private static final String BASE_URL = "http://api.twitter.com/1/";
 
  private static AsyncHttpClient client = new AsyncHttpClient();

  public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(getAbsoluteUrl(url), params, responseHandler);
  }

  public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.post(getAbsoluteUrl(url), params, responseHandler);
  }
      
  public static void getByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(url, params, responseHandler);
  }

  public static void postByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.post(url, params, responseHandler);
  }

  private static String getAbsoluteUrl(String relativeUrl) {
      return BASE_URL + relativeUrl;
  }
}

Call Method :

    RequestParams rp = new RequestParams();
    rp.add("username", "aaa"); rp.add("password", "aaa@123");
                    
    HttpUtils.post(AppConstant.URL_FEED, rp, new JsonHttpResponseHandler() {
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
            // If the response is JSONObject instead of expected JSONArray
            Log.d("asd", "---------------- this is response : " + response);
            try {
                JSONObject serverResp = new JSONObject(response.toString());                                                
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }                   
        }
            
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONArray timeline) {
            // Pull out the first event on the public timeline
                    
        }
    });

Please grant internet permission in your manifest file.

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

you can add compile 'com.loopj.android:android-async-http:1.4.9' for Header[] and compile 'org.json:json:20160212' for JSONObject in build.gradle file if required.

How to source virtualenv activate in a Bash script

Although it doesn't add the "(.env)" prefix to the shell prompt, I found this script works as expected.

#!/bin/bash
script_dir=`dirname $0`
cd $script_dir
/bin/bash -c ". ../.env/bin/activate; exec /bin/bash -i"

e.g.

user@localhost:~/src$ which pip
/usr/local/bin/pip
user@localhost:~/src$ which python
/usr/bin/python
user@localhost:~/src$ ./shell
user@localhost:~/src$ which pip
~/.env/bin/pip
user@localhost:~/src$ which python
~/.env/bin/python
user@localhost:~/src$ exit
exit

How do we change the URL of a working GitLab install?

There are detailed notes on this that helped me completely, located here.

Jonathon Reinhart has already answered with the key bit, to edit /etc/gitlab/gitlab.rb, alter the external_url and then run sudo gitlab-ctl reconfigure; sudo gitlab-ctl restart

However I needed to go a bit further and docs I linked above explained it. So what I ended up with looks like:

external_url 'https://gitlab.toilethumor.com'
nginx['ssl_certificate'] = "/www/ssl/star_toilethumor.com-chained.crt"
nginx['ssl_certificate_key'] = "/www/ssl/star_toilethumor.com.key"
nginx['proxy_set_headers'] = {
 "X-Forwarded-Proto" => "http",
 "CUSTOM_HEADER" => "VALUE"
}

Above, I've explicitly declared where my SSL goodies are on this server. And that's of course followed by

sudo gitlab-ctl reconfigure
sudo gitlab-ctl restart

Also, when you switch the omnibus package to https, the bundled nginx will only serve on port 443. Since all my stuff is reached via reverse proxy, this part was potentially significant.

As I went through this, I screwed something up and it helpful to find the actual nginx logs, this lead me there:

sudo gitlab-ctl tail nginx

Apply global variable to Vuejs

you can use Vuex to handle all your global data

Regex to match 2 digits, optional decimal, two digits

^(\d{0,2}\\.)?\d{1,2}$

\d{1,2}$ matches a 1-2 digit number with nothing after it (3, 33, etc.), (\d{0,2}\.)? matches optionally a number 0-2 digits long followed by a period (3., 44., ., etc.). Put them together and you've got your regex.

Adding author name in Eclipse automatically to existing files

Shift + Alt + J will help you add author name in existing file.

To add author name automatically,
go to Preferences --> --> Code Style --> Code Templates

Preferences -- Java -- Code Style -- Code Templates

in case you don't find above option in new versions of Eclipse - install it from https://marketplace.eclipse.org/content/jautodoc

Make a VStack fill the width of the screen in SwiftUI

 var body: some View {
      VStack {
           CarouselView().edgesIgnoringSafeArea(.all)           
           List {
                ForEach(viewModel.parents) { k in
                    VideosRowView(parent: k)
                }
           }
    }
 }

What does ECU units, CPU core and memory mean when I launch a instance

ECU = EC2 Compute Unit. More from here: http://aws.amazon.com/ec2/faqs/#What_is_an_EC2_Compute_Unit_and_why_did_you_introduce_it

Amazon EC2 uses a variety of measures to provide each instance with a consistent and predictable amount of CPU capacity. In order to make it easy for developers to compare CPU capacity between different instance types, we have defined an Amazon EC2 Compute Unit. The amount of CPU that is allocated to a particular instance is expressed in terms of these EC2 Compute Units. We use several benchmarks and tests to manage the consistency and predictability of the performance from an EC2 Compute Unit. One EC2 Compute Unit provides the equivalent CPU capacity of a 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor. This is also the equivalent to an early-2006 1.7 GHz Xeon processor referenced in our original documentation. Over time, we may add or substitute measures that go into the definition of an EC2 Compute Unit, if we find metrics that will give you a clearer picture of compute capacity.

Focus Input Box On Load

If you can't add to the BODY tag for some reason, you can add this AFTER the Form:

<SCRIPT type="text/javascript">
    document.yourFormName.yourFieldName.focus();
</SCRIPT>

Hive: Convert String to Integer

If the value is between –2147483648 and 2147483647, cast(string_filed as int) will work. else cast(string_filed as bigint) will work

    hive> select cast('2147483647' as int);
    OK
    2147483647
    
    hive> select cast('2147483648' as int);
    OK
    NULL
    
    hive> select cast('2147483648' as bigint);
    OK
    2147483648

How to retrieve a recursive directory and file list from PowerShell excluding some files and folders?

Recently, I explored the possibilities to parameterize the folder to scan through and the place where the result of recursive scan will be stored. At the end, I also did summarize the number of folders scanned and number of files inside as well. Sharing it with community in case it may help other developers.

    ##Script Starts
    #read folder to scan and file location to be placed

    $whichFolder = Read-Host -Prompt 'Which folder to Scan?'  
    $whereToPlaceReport = Read-Host -Prompt 'Where to place Report'
    $totalFolders = 1
    $totalFiles = 0

    Write-Host "Process started..."

    #IMP separator ? : used as a file in window cannot contain this special character in the file name

    #Get Foldernames into Variable for ForEach Loop
    $DFSFolders = get-childitem -path $whichFolder | where-object {$_.Psiscontainer -eq "True"} |select-object name ,fullName

    #Below Logic for Main Folder
    $mainFiles = get-childitem -path "C:\Users\User\Desktop" -file
    ("Folder Path" + "?" + "Folder Name" + "?" + "File Name " + "?"+ "File Length" )| out-file "$whereToPlaceReport\Report.csv" -Append

    #Loop through folders in main Directory
    foreach($file in $mainFiles)
    {

    $totalFiles = $totalFiles + 1
    ("C:\Users\User\Desktop" + "?" + "Main Folder" + "?"+ $file.name + "?" + $file.length ) | out-file "$whereToPlaceReport\Report.csv" -Append
    }


    foreach ($DFSfolder in $DFSfolders)
    {
    #write the folder name in begining
    $totalFolders = $totalFolders + 1

    write-host " Reading folder C:\Users\User\Desktop\$($DFSfolder.name)"
    #$DFSfolder.fullName | out-file "C:\Users\User\Desktop\PoC powershell\ok2.csv" -Append
    #For Each Folder obtain objects in a specified directory, recurse then filter for .sft file type, obtain the filename, then group, sort and eventually show the file name and total incidences of it.

    $files = get-childitem -path "$whichFolder\$($DFSfolder.name)" -recurse

    foreach($file in $files)
    {
    $totalFiles = $totalFiles + 1
    ($DFSfolder.fullName + "?" + $DFSfolder.name + "?"+ $file.name + "?" + $file.length ) | out-file "$whereToPlaceReport\Report.csv" -Append
    }

    }


    # If running in the console, wait for input before closing.
    if ($Host.Name -eq "ConsoleHost")
    {

    Write-Host "" 
    Write-Host ""
    Write-Host ""

    Write-Host  "                            **Summary**"  -ForegroundColor Red
    Write-Host  "                            ------------" -ForegroundColor Red

    Write-Host  "                           Total Folders Scanned = $totalFolders "  -ForegroundColor Green
    Write-Host  "                           Total Files   Scanned = $totalFiles "     -ForegroundColor Green

    Write-Host "" 
    Write-Host "" 
        Write-Host "I have done my Job,Press any key to exit" -ForegroundColor white
        $Host.UI.RawUI.FlushInputBuffer()   # Make sure buffered input doesn't "press a key" and skip the ReadKey().
        $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyUp") > $null
    }

##Output

enter image description here

##Bat Code to run above powershell command

@ECHO OFF
SET ThisScriptsDirectory=%~dp0
SET PowerShellScriptPath=%ThisScriptsDirectory%MyPowerShellScript.ps1
PowerShell -NoProfile -ExecutionPolicy Bypass -Command "& {Start-Process PowerShell -ArgumentList '-NoProfile -ExecutionPolicy Bypass -File ""%PowerShellScriptPath%""' -Verb RunAs}";

How to write loop in a Makefile?

A simple, shell/platform-independent, pure macro solution is ...

# GNU make (`gmake`) compatible; ref: <https://www.gnu.org/software/make/manual>
define EOL

$()
endef
%sequence = $(if $(word ${1},${2}),$(wordlist 1,${1},${2}),$(call %sequence,${1},${2} $(words _ ${2})))

.PHONY: target
target:
    $(foreach i,$(call %sequence,10),./a.out ${i}${EOL})

Perfect 100% width of parent container for a Bootstrap input?

Just add box-sizing:

input[type="text"] {
    box-sizing: border-box;
}

Is there a typescript List<> and/or Map<> class/library?

It's very easy to write that yourself, and that way you have more control over things.. As the other answers say, TypeScript is not aimed at adding runtime types or functionality.

Map:

class Map<T> {
    private items: { [key: string]: T };

    constructor() {
        this.items = {};
    }

    add(key: string, value: T): void {
        this.items[key] = value;
    }

    has(key: string): boolean {
        return key in this.items;
    }

    get(key: string): T {
        return this.items[key];
    }
}

List:

class List<T> {
    private items: Array<T>;

    constructor() {
        this.items = [];
    }

    size(): number {
        return this.items.length;
    }

    add(value: T): void {
        this.items.push(value);
    }

    get(index: number): T {
        return this.items[index];
    }
}

I haven't tested (or even tried to compile) this code, but it should give you a starting point.. you can of course then change what ever you want and add the functionality that YOU need...

As for your "special needs" from the List, I see no reason why to implement a linked list, since the javascript array lets you add and remove items.
Here's a modified version of the List to handle the get prev/next from the element itself:

class ListItem<T> {
    private list: List<T>;
    private index: number;

    public value: T;

    constructor(list: List<T>, value: T, index: number) {
        this.list = list;
        this.index = index;
        this.value = value;
    }

    prev(): ListItem<T> {
        return this.list.get(this.index - 1);
    }

    next(): ListItem<T> {
        return this.list.get(this.index + 1);   
    }
}

class List<T> {
    private items: Array<ListItem<T>>;

    constructor() {
        this.items = [];
    }

    size(): number {
        return this.items.length;
    }

    add(value: T): void {
        this.items.push(new ListItem<T>(this, value, this.size()));
    }

    get(index: number): ListItem<T> {
        return this.items[index];
    }
}

Here too you're looking at untested code..

Hope this helps.


Edit - as this answer still gets some attention

Javascript has a native Map object so there's no need to create your own:

let map = new Map();
map.set("key1", "value1");
console.log(map.get("key1")); // value1

Age from birthdate in python

The simplest way is using python-dateutil

import datetime

import dateutil

def birthday(date):
    # Get the current date
    now = datetime.datetime.utcnow()
    now = now.date()

    # Get the difference between the current date and the birthday
    age = dateutil.relativedelta.relativedelta(now, date)
    age = age.years

    return age

Vertically align an image inside a div with responsive height

Use this css, as you already have the markup for it:

.img-container {
    position: absolute;
    top: 50%;
    left: 50%;
}

.img-container > img {
  margin-top:-50%;
  margin-left:-50%;  
}

Here is a working JsBin: http://jsbin.com/ihilUnI/1/edit

This solution only works for square images (because a percentage margin-top value depends on the width of the container, not the height). For random-size images, you can do the following:

.img-container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%); /* add browser-prefixes */
}

Working JsBin solution: http://jsbin.com/ihilUnI/2/edit

Is there a portable way to get the current username in Python?

These might work. I don't know how they behave when running as a service. They aren't portable, but that's what os.name and ifstatements are for.

win32api.GetUserName()

win32api.GetUserNameEx(...) 

See: http://timgolden.me.uk/python/win32_how_do_i/get-the-owner-of-a-file.html

Get a random item from a JavaScript array

Use underscore (or loDash :)):

var randomArray = [
   '#cc0000','#00cc00', '#0000cc'
];

// use _.sample
var randomElement = _.sample(randomArray);

// manually use _.random
var randomElement = randomArray[_.random(randomArray.length-1)];

Or to shuffle an entire array:

// use underscore's shuffle function
var firstRandomElement = _.shuffle(randomArray)[0];

CSS - Syntax to select a class within an id

This will also work and you don't need the extra class:

#navigation li li {}

If you have a third level of LI's you may have to reset/override some of the styles they will inherit from the above selector. You can target the third level like so:

#navigation li li li {}

Java - Find shortest path between 2 points in a distance weighted map

Maintain a list of nodes you can travel to, sorted by the distance from your start node. In the beginning only your start node will be in the list.

While you haven't reached your destination: Visit the node closest to the start node, this will be the first node in your sorted list. When you visit a node, add all its neighboring nodes to your list except the ones you have already visited. Repeat!

Where can I get a list of Countries, States and Cities?

The UN maintains a list of countries and "states" / regions for economic trade. That DB is available here: http://www.unece.org/cefact/locode/welcome.html

How to use vagrant in a proxy environment?

The question does not mention the VM Provider but in my case, I use Virtual Box under the same environment. There is an option in the Virtual Box GUI that I needed to enable in order to make it work. Is located in the Virtual Box app preferences: File >> Preferences... >> Proxy. Once I configured this, I was able to work without problems. Hope this tip can also help you guys.

What's the best way to identify hidden characters in the result of a query in SQL Server (Query Analyzer)?

You can always use the DATALENGTH Function to determine if you have extra white space characters in text fields. This won't make the text visible but will show you where there are extra white space characters.

    SELECT DATALENGTH('MyTextData ') AS BinaryLength, LEN('MyTextData ') AS TextLength

This will produce 11 for BinaryLength and 10 for TextLength.

In a table your SQL would like this:

    SELECT * 
    FROM tblA
    WHERE DATALENGTH(MyTextField) > LEN(MyTextField)

This function is usable in all versions of SQL Server beginning with 2005.

What is String pool in Java?

When the JVM loads classes, or otherwise sees a literal string, or some code interns a string, it adds the string to a mostly-hidden lookup table that has one copy of each such string. If another copy is added, the runtime arranges it so that all the literals refer to the same string object. This is called "interning". If you say something like

String s = "test";
return (s == "test");

it'll return true, because the first and second "test" are actually the same object. Comparing interned strings this way can be much, much faster than String.equals, as there's a single reference comparison rather than a bunch of char comparisons.

You can add a string to the pool by calling String.intern(), which will give you back the pooled version of the string (which could be the same string you're interning, but you'd be crazy to rely on that -- you often can't be sure exactly what code has been loaded and run up til now and interned the same string). The pooled version (the string returned from intern) will be equal to any identical literal. For example:

String s1 = "test";
String s2 = new String("test");  // "new String" guarantees a different object

System.out.println(s1 == s2);  // should print "false"

s2 = s2.intern();
System.out.println(s1 == s2);  // should print "true"

How to use confirm using sweet alert?

document.querySelector('#from1').onsubmit = function(e){

 swal({
    title: "Are you sure?",
    text: "You will not be able to recover this imaginary file!",
    type: "warning",
    showCancelButton: true,
    confirmButtonColor: '#DD6B55',
    confirmButtonText: 'Yes, I am sure!',
    cancelButtonText: "No, cancel it!",
    closeOnConfirm: false,
    closeOnCancel: false
 },
 function(isConfirm){

   if (isConfirm){
     swal("Shortlisted!", "Candidates are successfully shortlisted!", "success");

    } else {
      swal("Cancelled", "Your imaginary file is safe :)", "error");
         e.preventDefault();
    }
 });
};

How to compile Go program consisting of multiple files?

When you separate code from main.go into for example more.go, you simply pass that file to go build/go run/go install as well.

So if you previously ran

go build main.go

you now simply

go build main.go more.go

As further information:

go build --help

states:

If the arguments are a list of .go files, build treats them as a list of source files specifying a single package.


Notice that go build and go install differ from go run in that the first two state to expect package names as arguments, while the latter expects go files. However, the first two will also accept go files as go install does.

If you are wondering: build will just build the packages/files, install will produce object and binary files in your GOPATH, and run will compile and run your program.

How to Lock/Unlock screen programmatically?

Edit:

As some folks needs help in Unlocking device after locking programmatically, I came through post Android screen lock/ unlock programatically, please have look, may help you.

Original Answer was:

You need to get Admin permission and you can lock phone screen

please check below simple tutorial to achive this one

Lock Phone Screen Programmtically

also here is the code example..

LockScreenActivity.java

public class LockScreenActivity extends Activity implements OnClickListener {  
 private Button lock;  
 private Button disable;  
 private Button enable;  
 static final int RESULT_ENABLE = 1;  

     DevicePolicyManager deviceManger;  
     ActivityManager activityManager;  
     ComponentName compName;  

    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  

        deviceManger = (DevicePolicyManager)getSystemService(  
          Context.DEVICE_POLICY_SERVICE);  
        activityManager = (ActivityManager)getSystemService(  
          Context.ACTIVITY_SERVICE);  
        compName = new ComponentName(this, MyAdmin.class);  

        setContentView(R.layout.main);  

        lock =(Button)findViewById(R.id.lock);  
        lock.setOnClickListener(this);  

        disable = (Button)findViewById(R.id.btnDisable);  
        enable =(Button)findViewById(R.id.btnEnable);  
        disable.setOnClickListener(this);  
        enable.setOnClickListener(this);  
    }  

 @Override  
 public void onClick(View v) {  

  if(v == lock){  
    boolean active = deviceManger.isAdminActive(compName);  
             if (active) {  
                 deviceManger.lockNow();  
             }  
  }  

  if(v == enable){  
   Intent intent = new Intent(DevicePolicyManager  
     .ACTION_ADD_DEVICE_ADMIN);  
            intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,  
                    compName);  
            intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,  
                    "Additional text explaining why this needs to be added.");  
            startActivityForResult(intent, RESULT_ENABLE);  
  }  

  if(v == disable){  
     deviceManger.removeActiveAdmin(compName);  
              updateButtonStates();  
  }    
 }  

 private void updateButtonStates() {  

        boolean active = deviceManger.isAdminActive(compName);  
        if (active) {  
            enable.setEnabled(false);  
            disable.setEnabled(true);  

        } else {  
            enable.setEnabled(true);  
            disable.setEnabled(false);  
        }      
 }  

  protected void onActivityResult(int requestCode, int resultCode, Intent data) {  
         switch (requestCode) {  
             case RESULT_ENABLE:  
                 if (resultCode == Activity.RESULT_OK) {  
                     Log.i("DeviceAdminSample", "Admin enabled!");  
                 } else {  
                     Log.i("DeviceAdminSample", "Admin enable FAILED!");  
                 }  
                 return;  
         }  
         super.onActivityResult(requestCode, resultCode, data);  
     }  
}

MyAdmin.java

public class MyAdmin extends DeviceAdminReceiver{  


    static SharedPreferences getSamplePreferences(Context context) {  
        return context.getSharedPreferences(  
          DeviceAdminReceiver.class.getName(), 0);  
    }  

    static String PREF_PASSWORD_QUALITY = "password_quality";  
    static String PREF_PASSWORD_LENGTH = "password_length";  
    static String PREF_MAX_FAILED_PW = "max_failed_pw";  

    void showToast(Context context, CharSequence msg) {  
        Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();  
    }  

    @Override  
    public void onEnabled(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: enabled");  
    }  

    @Override  
    public CharSequence onDisableRequested(Context context, Intent intent) {  
        return "This is an optional message to warn the user about disabling.";  
    }  

    @Override  
    public void onDisabled(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: disabled");  
    }  

    @Override  
    public void onPasswordChanged(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: pw changed");  
    }  

    @Override  
    public void onPasswordFailed(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: pw failed");  
    }  

    @Override  
    public void onPasswordSucceeded(Context context, Intent intent) {  
        showToast(context, "Sample Device Admin: pw succeeded");  
    }  

}

How to change ReactJS styles dynamically?

Ok, finally found the solution.

Probably due to lack of experience with ReactJS and web development...

    var Task = React.createClass({
    render: function() {
      var percentage = this.props.children + '%';
      ....
        <div className="ui-progressbar-value ui-widget-header ui-corner-left" style={{width : percentage}}/>
      ...

I created the percentage variable outside in the render function.

How to enable/disable bluetooth programmatically in android

try this:

//this method to check bluetooth is enable or not: true if enable, false is not enable
public static boolean isBluetoothEnabled()
    {
        BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (!mBluetoothAdapter.isEnabled()) {
            // Bluetooth is not enable :)
            return false;
        }
        else{
            return true;
        }

    }

//method to enable bluetooth
    public static void enableBluetooth(){
        BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (!mBluetoothAdapter.isEnabled()) {
            mBluetoothAdapter.enable();
        }
    }

//method to disable bluetooth
    public static void disableBluetooth(){
        BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (mBluetoothAdapter.isEnabled()) {
            mBluetoothAdapter.disable();
        }
    }

Add these permissions in manifest

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>