Programs & Examples On #Business logic layer

The business logic layer (BLL) is the layer in a multi-layer software architecture which separates the business logic from other layers such as the data access layer (DAL) and user interface (UI or presentation layer).

Separation of business logic and data access in django

I'm mostly agree with chosen answer (https://stackoverflow.com/a/12857584/871392), but want to add option in Making Queries section.

One can define QuerySet classes for models for make filter queries and so on. After that you can proxy this queryset class for model's manager, like build-in Manager and QuerySet classes do.

Although, if you had to query several data models to get one domain model, it seems more reasonable to me to put this in separate module like suggested before.

Displaying the build date

A different, PCL-friendly approach would be to use an MSBuild inline task to substitute the build time into a string that is returned by a property on the app. We are using this approach successfully in an app that has Xamarin.Forms, Xamarin.Android, and Xamarin.iOS projects.

EDIT:

Simplified by moving all of the logic into the SetBuildDate.targets file, and using Regex instead of simple string replace so that the file can be modified by each build without a "reset".

The MSBuild inline task definition (saved in a SetBuildDate.targets file local to the Xamarin.Forms project for this example):

<Project xmlns='http://schemas.microsoft.com/developer/msbuild/2003' ToolsVersion="12.0">

  <UsingTask TaskName="SetBuildDate" TaskFactory="CodeTaskFactory" 
    AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v12.0.dll">
    <ParameterGroup>
      <FilePath ParameterType="System.String" Required="true" />
    </ParameterGroup>
    <Task>
      <Code Type="Fragment" Language="cs"><![CDATA[

        DateTime now = DateTime.UtcNow;
        string buildDate = now.ToString("F");
        string replacement = string.Format("BuildDate => \"{0}\"", buildDate);
        string pattern = @"BuildDate => ""([^""]*)""";
        string content = File.ReadAllText(FilePath);
        System.Text.RegularExpressions.Regex rgx = new System.Text.RegularExpressions.Regex(pattern);
        content = rgx.Replace(content, replacement);
        File.WriteAllText(FilePath, content);
        File.SetLastWriteTimeUtc(FilePath, now);

   ]]></Code>
    </Task>
  </UsingTask>

</Project>

Invoking the above inline task in the Xamarin.Forms csproj file in target BeforeBuild:

  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
       Other similar extension points exist, see Microsoft.Common.targets.  -->
  <Import Project="SetBuildDate.targets" />
  <Target Name="BeforeBuild">
    <SetBuildDate FilePath="$(MSBuildProjectDirectory)\BuildMetadata.cs" />
  </Target>

The FilePath property is set to a BuildMetadata.cs file in the Xamarin.Forms project that contains a simple class with a string property BuildDate, into which the build time will be substituted:

public class BuildMetadata
{
    public static string BuildDate => "This can be any arbitrary string";
}

Add this file BuildMetadata.cs to project. It will be modified by every build, but in a manner that allows repeated builds (repeated replacements), so you may include or omit it in source control as desired.

Byte Array and Int conversion in Java

I found a simple way in com.google.common.primitives which is in the [Maven:com.google.guava:guava:12.0.1]

long newLong = Longs.fromByteArray(oldLongByteArray);
int newInt = Ints.fromByteArray(oldIntByteArray);

Have a nice try :)

How to count check-boxes using jQuery?

You can do it by using name attibute, class, id or just universal checkbox; If you want to count only checked number of checkbox.

By the class name :

var countChk = $('checkbox.myclassboxName:checked').length;

By name attribute :

var countByName= $('checkbox[name=myAllcheckBoxName]:checked').length;

Complete code

$('checkbox.className').blur(function() {
    //count only checked checkbox 
    $('checkbox[name=myAllcheckBoxName]:checked').length;
});

How to convert this var string to URL in Swift

To Convert file path in String to NSURL, observe the following code

var filePathUrl = NSURL.fileURLWithPath(path)

C# elegant way to check if a property's property is null

You're obviously looking for the Nullable Monad:

string result = new A().PropertyB.PropertyC.Value;

becomes

string result = from a in new A()
                from b in a.PropertyB
                from c in b.PropertyC
                select c.Value;

This returns null, if any of the nullable properties are null; otherwise, the value of Value.

class A { public B PropertyB { get; set; } }
class B { public C PropertyC { get; set; } }
class C { public string Value { get; set; } }

LINQ extension methods:

public static class NullableExtensions
{
    public static TResult SelectMany<TOuter, TInner, TResult>(
        this TOuter source,
        Func<TOuter, TInner> innerSelector,
        Func<TOuter, TInner, TResult> resultSelector)
        where TOuter : class
        where TInner : class
        where TResult : class
    {
        if (source == null) return null;
        TInner inner = innerSelector(source);
        if (inner == null) return null;
        return resultSelector(source, inner);
    }
}

ALTER TABLE, set null in not null column, PostgreSQL 9.1

ALTER TABLE person ALTER COLUMN phone DROP NOT NULL;

More details in the manual: http://www.postgresql.org/docs/9.1/static/sql-altertable.html

ASP.NET Forms Authentication failed for the request. Reason: The ticket supplied has expired

I was getting this same error, in our case it was caused by a load balancer. We hade to make sure that the persistance was set to Source IP. Otherwise the login form was opened by one server, and processed by the other, which would fail to set the authentication cookie correctly. Maybe this helps someone else

remove empty lines from text file with PowerShell

This removes trailing whitespace and blank lines from file.txt

PS C:\Users\> (gc file.txt) | Foreach {$_.TrimEnd()} | where {$_ -ne ""} | Set-Content file.txt

What is pluginManagement in Maven's pom.xml?

The difference between <pluginManagement/> and <plugins/> is that a <plugin/> under:

  • <pluginManagement/> defines the settings for plugins that will be inherited by modules in your build. This is great for cases where you have a parent pom file.

  • <plugins/> is a section for the actual invocation of the plugins. It may or may not be inherited from a <pluginManagement/>.

You don't need to have a <pluginManagement/> in your project, if it's not a parent POM. However, if it's a parent pom, then in the child's pom, you need to have a declaration like:

<plugins>
    <plugin>
        <groupId>com.foo</groupId>
        <artifactId>bar-plugin</artifactId>
    </plugin>
</plugins>

Notice how you aren't defining any configuration. You can inherit it from the parent, unless you need to further adjust your invocation as per the child project's needs.

For more specific information, you can check:

What is %timeit in python?

IPython intercepts those, they're called built-in magic commands, here's the list: https://ipython.org/ipython-doc/dev/interactive/magics.html

You can also create your own custom magics, https://ipython.org/ipython-doc/dev/config/custommagics.html

Your timeit is here https://ipython.org/ipython-doc/dev/interactive/magics.html#magic-timeit

Regex Match all characters between two strings

In case anyone is looking for an example of this within a Jenkins context. It parses the build.log and if it finds a match it fails the build with the match.

import java.util.regex.Matcher;
import java.util.regex.Pattern;

node{    
    stage("parse"){
        def file = readFile 'build.log'

        def regex = ~"(?s)(firstStringToUse(.*)secondStringToUse)"
        Matcher match = regex.matcher(file)
        match.find() {
            capturedText = match.group(1)
            error(capturedText)
        }
    }
}

bootstrap 3 navbar collapse button not working

I had a similar problem. Looked over the html several times and was sure it was correct. Then I started playing around with the order of jquery and bootstrap javascript.

Originally I had bootstrap.min.js loading BEFORE jquery.min.js. In this state, the menu would not expand when clicking on the menu icon.

Then I changed the order so that bootstrap.min.js came after jquery.min.js, and this solved the problem. I don't know enough about javascript to explain why this caused the problem (or fixed it), but that is what worked for me.

Additional info:

Both scripts are located at the bottom of the page, just before the tag. Both scripts are hosted on CDNs, not locally hosted.

If you're pretty sure your code is correct, give this a try.

JavaScriptSerializer - JSON serialization of enum as string

And for VB.net I found the following works:

Dim sec = New Newtonsoft.Json.Converters.StringEnumConverter()
sec.NamingStrategy() = New Serialization.CamelCaseNamingStrategy

Dim JSON_s As New JsonSerializer
JSON_s.Converters.Add(sec)

Dim jsonObject As JObject
jsonObject = JObject.FromObject(SomeObject, JSON_s)
Dim text = jsonObject.ToString

IO.File.WriteAllText(filePath, text)

javac: file not found: first.java Usage: javac <options> <source files>

first set the path of jdk bin steps to be follow: - open computer properties. - Advanced system settings - Environment Variables look for the system variables -Click on the "path" variable - Edit copy the jdk bin path and done.

The Problem is you just open the command prompt which is default set on current user like "C:\users\ABC>" You have to change the location where your .java file store like "D:\javafiles>"

Now you are able to run the command javac filename.java

What is the maximum characters for the NVARCHAR(MAX)?

From MSDN Documentation

nvarchar [ ( n | max ) ]

Variable-length Unicode string data. n defines the string length and can be a value from 1 through 4,000. max indicates that the maximum storage size is 2^31-1 bytes (2 GB). The storage size, in bytes, is two times the actual length of data entered + 2 bytes

How do I pass data between Activities in Android application?

1st way: In your current Activity, when you create object of intent to open new screen:

  String value="xyz";
  Intent intent = new Intent(CurrentActivity.this, NextActivity.class);    
  intent.putExtra("key", value);
  startActivity(intent);

Then in the nextActivity in onCreate method, retrieve those values which you pass from previous activity:

  if (getIntent().getExtras() != null) {
      String value = getIntent().getStringExtra("key");
      //The key argument must always match that used send and retrive value from one activity to another.
  }

2nd way: You can create bundle object and put values in bundle and then put bundle object in intent from your current activity -

  String value="xyz";
  Intent intent = new Intent(CurrentActivity.this, NextActivity.class);  
  Bundle bundle = new Bundle();
  bundle.putInt("key", value);  
  intent.putExtra("bundle_key", bundle);
  startActivity(intent);

Then in the nextActivity in onCreate method, retrieve those values which you pass from previous activity:

  if (getIntent().getExtras() != null) {
      Bundle bundle = getIntent().getStringExtra("bundle_key");    
      String value = bundle.getString("key");
      //The key argument must always match that used send and retrive value from one activity to another.
  }

You can also use bean class to pass data between classes using serialization.

How to display databases in Oracle 11g using SQL*Plus

SELECT NAME FROM v$database; shows the database name in oracle

Single TextView with multiple colored text

if (Build.VERSION.SDK_INT >= 24) {
     Html.fromHtml(String, flag) // for 24 API  and more
 } else {
     Html.fromHtml(String) // or for older API 
 }

for 24 API and more (flag)

public static final int FROM_HTML_MODE_COMPACT = 63;
public static final int FROM_HTML_MODE_LEGACY = 0;
public static final int FROM_HTML_OPTION_USE_CSS_COLORS = 256;
public static final int FROM_HTML_SEPARATOR_LINE_BREAK_BLOCKQUOTE = 32;
public static final int FROM_HTML_SEPARATOR_LINE_BREAK_DIV = 16;
public static final int FROM_HTML_SEPARATOR_LINE_BREAK_HEADING = 2;
public static final int FROM_HTML_SEPARATOR_LINE_BREAK_LIST = 8;
public static final int FROM_HTML_SEPARATOR_LINE_BREAK_LIST_ITEM = 4;
public static final int FROM_HTML_SEPARATOR_LINE_BREAK_PARAGRAPH = 1;
public static final int TO_HTML_PARAGRAPH_LINES_CONSECUTIVE = 0;
public static final int TO_HTML_PARAGRAPH_LINES_INDIVIDUAL = 1;

More Info

How do I set an absolute include path in PHP?

Another option is to create a file in the $_SERVER['DOCUMENT_ROOT'] directory with the definition of your absolute path.

For example, if your $_SERVER['DOCUMENT_ROOT'] directory is

C:\wamp\www\

create a file (i.e. my_paths.php) containing this

<?php if(!defined('MY_ABS_PATH')) define('MY_ABS_PATH',$_SERVER['DOCUMENT_ROOT'].'MyProyect/')

Now you only need to include in every file inside your MyProyect folder this file (my_paths.php), so you can user MY_ABS_PATH as an absolute path for MyProject.

How can I put strings in an array, split by new line?

Using only the 'base' package is also a solution for simple cases:

> s <- "a\nb\rc\r\nd"
> l <- strsplit(s,"\r\n|\n|\r")
> l  # the whole list...
[[1]]
[1] "a" "b" "c" "d"
> l[[1]][1] # ... or individual elements
[1] "a"
> l[[1]][2]
[1] "b"
> fun <- function(x) c('Line content:', x) # handle as you wish
> lapply(unlist(l), fun)

How to insert the current timestamp into MySQL database using a PHP insert query

Don't like any of those solutions.

this is how i do it:

$update_query = "UPDATE db.tablename SET insert_time=now() WHERE username='" 
            . sqlEsc($somename) . "' ;";

then i use my own sqlEsc function:

function sqlEsc($val) 
{
    global $mysqli;
    return mysqli_real_escape_string($mysqli, $val);
}

Get a list of all functions and procedures in an Oracle database

SELECT * FROM ALL_OBJECTS WHERE OBJECT_TYPE IN ('FUNCTION','PROCEDURE','PACKAGE')

The column STATUS tells you whether the object is VALID or INVALID. If it is invalid, you have to try a recompile, ORACLE can't tell you if it will work before.

How do I get elapsed time in milliseconds in Ruby?

I think the answer is incorrectly chosen, that method gives seconds, not milliseconds.

t = Time.now.t­o_f
=> 1382471965.146

Here I suppose the floating value are the milliseconds

Difference between View and ViewGroup in Android

In simple words View is the UI element which we interact with when we use an app,like button,edit text and image etc.View is the child class of Android.view.View While View group is the container which contains all these views inside it in addition to several othe viewgroups like linear or Frame Layout etc. Example if we design & take the root element as Linear layout now our main layout is linear layout inside it we can take another view group (i.e another Linear layout) & many other views like buttons or textview etc.

Create a .tar.bz2 file Linux

Try this from different folder:

sudo tar -cvjSf folder.tar.bz2 folder/*

symfony2 : failed to write cache directory

I move the whole directory from my Windows installation to a unix production server and I got the same error. To fix it, I just ran these two lines in unix and everything started to run fine

rm -rf app/cache/*
rm -rf app/logs/*

xsd:boolean element type accept "true" but not "True". How can I make it accept it?

You cannot.

According to the XML Schema specification, a boolean is true or false. True is not valid:


  3.2.2.1 Lexical representation
  An instance of a datatype that is defined as ·boolean· can have the 
  following legal literals {true, false, 1, 0}. 

  3.2.2.2 Canonical representation
  The canonical representation for boolean is the set of 
  literals {true, false}. 

If the tool you are using truly validates against the XML Schema standard, then you cannot convince it to accept True for a boolean.

Get file version in PowerShell

Here an alternative method. It uses Get-WmiObject CIM_DATAFILE to select the version.

(Get-WmiObject -Class CIM_DataFile -Filter "Name='C:\\Windows\\explorer.exe'" | Select-Object Version).Version

how to call scalar function in sql server 2008

For some reason I was not able to use my scalar function until I referenced it using brackets, like so:

select [dbo].[fun_functional_score]('01091400003')

XPath selecting a node with some attribute value equals to some other node's attribute value

I think this is what you want:

/grand/parent/child[@id="#grand"]

check if a file is open in Python

Using

try:
with open("path", "r") as file:#or just open

may cause some troubles when file is opened by some other processes (i.e. user opened it manually). You can solve your poblem using win32com library. Below code checks if any excel files are opened and if none of them matches the name of your particular one, openes a new one.

import win32com.client as win32
xl = win32.gencache.EnsureDispatch('Excel.Application')

my_workbook = "wb_name.xls"
xlPath="my_wb_path//" + my_workbook


if xl.Workbooks.Count > 0:
    # if none of opened workbooks matches the name, openes my_workbook 
    if not any(i.Name == my_workbook for i in xl.Workbooks): 
        xl.Workbooks.Open(Filename=xlPath)
        xl.Visible = True
#no workbooks found, opening
else:  
    xl.Workbooks.Open(Filename=xlPath)
    xl.Visible = True

'xl.Visible = True is not necessary, used just for convenience'

Hope this will help

Deleting elements from std::set while iterating

C++20 will have "uniform container erasure", and you'll be able to write:

std::erase_if(numbers, [](int n){ return n % 2 == 0 });

And that will work for vector, set, deque, etc. See cppReference for more info.

document.getelementbyId will return null if element is not defined?

console.log(document.getElementById('xx') ) evaluates to null.

document.getElementById('xx') !=null evaluates to false

You should use document.getElementById('xx') !== null as it is a stronger equality check.

How to know the git username and email saved during configuration?

If you want to check or set the user name and email you can use the below command

Check user name

git config user.name

Set user name

git config user.name "your_name"

Check your email

git config user.email

Set/change your email

git config user.email "[email protected]"

List/see all configuration

git config --list

C# Pass Lambda Expression as Method Parameter

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

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

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

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

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

How do I set up HttpContent for my HttpClient PostAsync second parameter?

    public async Task<ActionResult> Index()
    {
        apiTable table = new apiTable();
        table.Name = "Asma Nadeem";
        table.Roll = "6655";

        string str = "";
        string str2 = "";

        HttpClient client = new HttpClient();

        string json = JsonConvert.SerializeObject(table);

        StringContent httpContent = new StringContent(json, System.Text.Encoding.UTF8, "application/json");

        var response = await client.PostAsync("http://YourSite.com/api/apiTables", httpContent);

        str = "" + response.Content + " : " + response.StatusCode;

        if (response.IsSuccessStatusCode)
        {       
            str2 = "Data Posted";
        }

        return View();
    }

How to run Node.js as a background process and never die?

nohup node server.js > /dev/null 2>&1 &

  1. nohup means: Do not terminate this process even when the stty is cut off.
  2. > /dev/null means: stdout goes to /dev/null (which is a dummy device that does not record any output).
  3. 2>&1 means: stderr also goes to the stdout (which is already redirected to /dev/null). You may replace &1 with a file path to keep a log of errors, e.g.: 2>/tmp/myLog
  4. & at the end means: run this command as a background task.

No resource found that matches the given name '@style/Theme.AppCompat.Light'

The steps described above do work, however I've encountered this problem on IntelliJ IDEA and have found that I'm having these problems with existing projects and the only solution is to remove the 'appcompat' module (not the library) and re-import it.

Difference between string and char[] types in C++

Arkaitz is correct that string is a managed type. What this means for you is that you never have to worry about how long the string is, nor do you have to worry about freeing or reallocating the memory of the string.

On the other hand, the char[] notation in the case above has restricted the character buffer to exactly 256 characters. If you tried to write more than 256 characters into that buffer, at best you will overwrite other memory that your program "owns". At worst, you will try to overwrite memory that you do not own, and your OS will kill your program on the spot.

Bottom line? Strings are a lot more programmer friendly, char[]s are a lot more efficient for the computer.

Expression must be a modifiable L-value

lvalue means "left value" -- it should be assignable. You cannot change the value of text since it is an array, not a pointer.

Either declare it as char pointer (in this case it's better to declare it as const char*):

const char *text;
if(number == 2) 
    text = "awesome"; 
else 
    text = "you fail";

Or use strcpy:

char text[60];
if(number == 2) 
    strcpy(text, "awesome"); 
else 
    strcpy(text, "you fail");

Simple example for Intent and Bundle

For example :

In MainActivity :

Intent intent = new Intent(this, OtherActivity.class);
intent.putExtra(OtherActivity.KEY_EXTRA, yourDataObject);
startActivity(intent);

In OtherActivity :

public static final String KEY_EXTRA = "com.example.yourapp.KEY_BOOK";

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  String yourDataObject = null;

  if (getIntent().hasExtra(KEY_EXTRA)) {
      yourDataObject = getIntent().getStringExtra(KEY_EXTRA);
  } else {
      throw new IllegalArgumentException("Activity cannot find  extras " + KEY_EXTRA);
  }
  // do stuff
}

More informations here : http://developer.android.com/reference/android/content/Intent.html

When to use: Java 8+ interface default method, vs. abstract method

Whenever we have a choice between abstract class and interface we should always (almost) prefer default (also known as defender or virtual extensions) methods.

  1. Default methods have put an end to classic pattern of interface and a companion class that implements most or all of the methods in that interface. An example is Collection and AbstractCollection. Now we should implement the methods in the interface itself to provide default functionality. The classes which implement the interface has choice to override the methods or inherit the default implementation.

  2. Another important use of default methods is interface evolution. Suppose I had a class Ball as:

    public class Ball implements Collection { ... }

Now in Java 8 a new feature streams in introduced. We can get a stream by using stream method added to the interface. If stream were not a default method all the implementations for Collection interface would have broken as they would not be implementing this new method. Adding a non-default method to an interface is not source-compatible.

But suppose we do not recompile the class and use an old jar file which contains this class Ball. The class will load fine without this missing method, instances can be created and it seems everything is working fine. BUT if program invokes stream method on instance of Ball we will get AbstractMethodError. So making method default solved both the problems.

Java 9 has got even private methods in interface which can be used to encapsulate the common code logic that was used in the interface methods that provided a default implementation.

HTML5 Email input pattern attribute

In HTML5 you can use the new 'email' type: http://www.w3.org/TR/html-markup/input.email.html

For example:

<input type="email" id="email" />

If the browser implements HTML5 it will make sure that the user has entered a valid email address in the field. Note that if the browser doesn't implement HTML5, it will be treated like a 'text' type, ie:

<input type="text" id="email" />

Material effect on button with background color

I used the backgroundTint and foreground:

<Button
    android:layout_width="match_parent"
    android:layout_height="40dp"
    android:backgroundTint="@color/colorAccent"
    android:foreground="?android:attr/selectableItemBackground"
    android:textColor="@android:color/white"
    android:textSize="10sp"/>

Pass table as parameter into sql server UDF

The following will enable you to quickly remove the duplicate,null values and return only the valid one as list.

CREATE TABLE DuplicateTable (Col1 INT)
INSERT INTO DuplicateTable
SELECT 8
UNION ALL
SELECT 1--duplicate
UNION ALL
SELECT 2 --duplicate
UNION ALL
SELECT 1
UNION ALL
SELECT 3
UNION ALL
SELECT 4
UNION ALL
SELECT 5
UNION 
SELECT NULL
GO

WITH CTE (COl1,DuplicateCount)
AS
(
SELECT COl1,
ROW_NUMBER() OVER(PARTITION BY COl1 ORDER BY Col1) AS DuplicateCount
FROM DuplicateTable
WHERE (col1 IS NOT NULL) 
)
SELECT COl1
FROM CTE
WHERE DuplicateCount =1
GO

CTE are valid in SQL 2005 , you could then store the values in a temp table and use it with your function.

How to efficiently change image attribute "src" from relative URL to absolute using jQuery?

Your code can simplified a lot to

$('img', resp).attr('src', function(idx, urlRelative ) {
    return self.config.proxy_server + self.config.location_images + urlRelative;
});

Display date in dd/mm/yyyy format in vb.net

Try this.

 var dateAsString = DateTime.Now.ToString("dd/MM/yyyy");
// dateAsString = "09/07/2013"

and also check this link for more formatting data and time

How to TryParse for Enum value?

There's currently no out of the box Enum.TryParse. This has been requested on Connect (Still no Enum.TryParse) and got a response indicating possible inclusion in the next framework after .NET 3.5. You'll have to implement the suggested workarounds for now.

How to escape indicator characters (i.e. : or - ) in YAML

According to the YAML spec, neither the : nor the - should be a problem. : is only a key separator with a space after it, and - is only an array indicator at the start of a line with a space after it.

But if your YAML implementation has a problem with it, you potentially have lots of options:

- url: 'http://www.example-site.com/'
- url: "http://www.example-site.com/"
- url:
    http://www.example-site.com/
- url: >-
    http://www.example-site.com/
- url: |-
    http://www.example-site.com/

There is explicitly no form of escaping possible in "plain style", however.

using jquery $.ajax to call a PHP function

You may use my library that does that automatically, I've been improving it for the past 2 years http://phery-php-ajax.net

Phery::instance()->set(array(
   'phpfunction' => function($data){
      /* Do your thing */
      return PheryResponse::factory(); // do your dom manipulation, return JSON, etc
   }
))->process();

The javascript would be simple as

phery.remote('phpfunction');

You can pass all the dynamic javascript part to the server, with a query builder like chainable interface, and you may pass any type of data back to the PHP. For example, some functions that would take too much space in the javascript side, could be called in the server using this (in this example, mcrypt, that in javascript would be almost impossible to accomplish):

function mcrypt(variable, content, key){
  phery.remote('mcrypt_encrypt', {'var': variable, 'content': content, 'key':key || false});
}

//would use it like (you may keep the key on the server, safer, unless it's encrypted for the user)
window.variable = '';
mcrypt('variable', 'This must be encoded and put inside variable', 'my key');

and in the server

Phery::instance()->set(array(
  'mcrypt_encrypt' => function($data){
     $r = new PheryResponse;

     $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
     $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
     $encrypted = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $data['key'] ? : 'my key', $data['content'], MCRYPT_MODE_ECB, $iv);
     return $r->set_var($data['variable'], $encrypted);
     // or call a callback with the data, $r->call($data['callback'], $encrypted);
  }
))->process();

Now the variable will have the encrypted data.

SMTP error 554

Can be caused by a miss configured SPF record on the senders end.

Unix tail equivalent command in Windows Powershell

I took @hajamie's solution and wrapped it up into a slightly more convenient script wrapper.

I added an option to start from an offset before the end of the file, so you can use the tail-like functionality of reading a certain amount from the end of the file. Note the offset is in bytes, not lines.

There's also an option to continue waiting for more content.

Examples (assuming you save this as TailFile.ps1):

.\TailFile.ps1 -File .\path\to\myfile.log -InitialOffset 1000000
.\TailFile.ps1 -File .\path\to\myfile.log -InitialOffset 1000000 -Follow:$true
.\TailFile.ps1 -File .\path\to\myfile.log -Follow:$true

And here is the script itself...

param (
    [Parameter(Mandatory=$true,HelpMessage="Enter the path to a file to tail")][string]$File = "",
    [Parameter(Mandatory=$true,HelpMessage="Enter the number of bytes from the end of the file")][int]$InitialOffset = 10248,
    [Parameter(Mandatory=$false,HelpMessage="Continuing monitoring the file for new additions?")][boolean]$Follow = $false
)

$ci = get-childitem $File
$fullName = $ci.FullName

$reader = new-object System.IO.StreamReader(New-Object IO.FileStream($fullName, [System.IO.FileMode]::Open, [System.IO.FileAccess]::Read, [IO.FileShare]::ReadWrite))
#start at the end of the file
$lastMaxOffset = $reader.BaseStream.Length - $InitialOffset

while ($true)
{
    #if the file size has not changed, idle
    if ($reader.BaseStream.Length -ge $lastMaxOffset) {
        #seek to the last max offset
        $reader.BaseStream.Seek($lastMaxOffset, [System.IO.SeekOrigin]::Begin) | out-null

        #read out of the file until the EOF
        $line = ""
        while (($line = $reader.ReadLine()) -ne $null) {
            write-output $line
        }

        #update the last max offset
        $lastMaxOffset = $reader.BaseStream.Position
    }

    if($Follow){
        Start-Sleep -m 100
    } else {
        break;
    }
}

How do you cast a List of supertypes to a List of subtypes?

This should would work

List<TestA> testAList = new ArrayList<>();
List<TestB> testBList = new ArrayList<>()
testAList.addAll(new ArrayList<>(testBList));

The intel x86 emulator accelerator (HAXM installer) revision 6.0.5 is showing not compatible with windows

Did you read https://software.intel.com/en-us/blogs/2014/03/14/troubleshooting-intel-haxm?

It says "Make sure "Hyper-V", a Windows feature, is not installed/enabled on your system. Hyper-V captures the VT virtualization capability of the CPU, and HAXM and Hyper-V cannot run at the same time. Read this blog: Creating a "no hypervisor" boot entry." https://blogs.msdn.microsoft.com/virtual_pc_guy/2008/04/14/creating-a-no-hypervisor-boot-entry/

I've created the boot entry that disables HyperV and it's working

Rename a table in MySQL

RENAME TABLE tb1 TO tb2;

tb1 - current table name. tb2 - the name you want your table to be called.

Where do alpha testers download Google Play Android apps?

Another issue of that page if you use multiple playstore accounts:

In some cases you still get a 404, even if you are currently logged in with the right account, the one you joined the beta community with. As a workaround, you can clear the browser cache, use another browser for the beta signup, or just use the incognito mode of your browser.

Generating a PDF file from React Components

You can use ReactDOMServer to render your component to HTML and then use this on jsPDF.

First do the imports:

import React from "react";
import ReactDOMServer from "react-dom/server";
import jsPDF from 'jspdf';

then:

var doc = new jsPDF();
doc.fromHTML(ReactDOMServer.renderToStaticMarkup(this.render()));
doc.save("myDocument.pdf");

Prefer to use:

renderToStaticMarkup

instead of:

renderToString

As the former include HTML code that react relies on.

Python: Find a substring in a string and returning the index of the substring

late to the party, was searching for same, as "in" is not valid, I had just created following.

def find_str(full, sub):
    index = 0
    sub_index = 0
    position = -1
    for ch_i,ch_f in enumerate(full) :
        if ch_f.lower() != sub[sub_index].lower():
            position = -1
            sub_index = 0
        if ch_f.lower() == sub[sub_index].lower():
            if sub_index == 0 :
                position = ch_i

            if (len(sub) - 1) <= sub_index :
                break
            else:
                sub_index += 1

    return position

print(find_str("Happy birthday", "py"))
print(find_str("Happy birthday", "rth"))
print(find_str("Happy birthday", "rh"))

which produces

3
8
-1

remove lower() in case case insensitive find not needed.

How to access Anaconda command prompt in Windows 10 (64-bit)

How to add anaconda installation directory to your PATH variables

1. open environmental variables window

Do this by either going to my computer and then right clicking the background for the context menu > "properties". On the left side open "advanced system settings" or just search for "env..." in start menu ([Win]+[s] keys).

Then click on environment variables

If you struggle with this step read this explanation.

2. Edit Path in the user environmental variables section and add three new entries:

  • D:\path\to\anaconda3
  • D:\path\to\anaconda3\Scripts
  • D:\path\to\anaconda3\Library\bin

D:\path\to\anaconda3 should be the folder where you have installed anaconda

Click [OK] on all opened windows.

If you did everything correctly, you can test a conda command by opening a new powershell window.

conda --version

This should output something like: conda 4.8.2

Error:Unable to locate adb within SDK in Android Studio

try this: File->project Structure into Project Structure Left > SDKs SDK location select Android SDK location (old version use Press +, add another sdk)

Remove the newline character in a list read from a file

You could actually put the newlines to good use by reading the entire file into memory as a single long string and then use them to split that into the list of grades.

with open("grades.dat") as input:
    grades = [line.split(",") for line in input.read().splitlines()]
etc...

How to retrieve form values from HTTPPOST, dictionary or?

You could have your controller action take an object which would reflect the form input names and the default model binder will automatically create this object for you:

[HttpPost]
public ActionResult SubmitAction(SomeModel model)
{
    var value1 = model.SimpleProp1;
    var value2 = model.SimpleProp2;
    var value3 = model.ComplexProp1.SimpleProp1;
    ...

    ... return something ...
}

Another (obviously uglier) way is:

[HttpPost]
public ActionResult SubmitAction()
{
    var value1 = Request["SimpleProp1"];
    var value2 = Request["SimpleProp2"];
    var value3 = Request["ComplexProp1.SimpleProp1"];
    ...

    ... return something ...
}

IIS Manager in Windows 10

It most likely means that IIS Management Console was not installed, and modern Windows administrator/IT pro should be able to quickly check this by issuing this command:

Get-WindowsFeature *Web*

And if it is missing just quickly add this via the following command:

Add-WindowsFeature Web-Mgmt-Console

GUI options mentioned above are also valid (see answer from @Joe Wu) but PowerShell it is best way to do IT for IT Pro or let's put it as "if you have to do this slightly more often than once a year" :)

String to HashMap JAVA

Use StringTokenizer to parse the string.

String s ="SALES:0,SALE_PRODUCTS:1,EXPENSES:2,EXPENSES_ITEMS:3";
    Map<String, Integer> lMap=new HashMap<String, Integer>();


    StringTokenizer st=new StringTokenizer(s, ",");
    while(st.hasMoreTokens())
    {
        String [] array=st.nextToken().split(":");
        lMap.put(array[0], Integer.valueOf(array[1]));
    }

Pandas group-by and sum

You can set the groupby column to index then using sum with level

df.set_index(['Fruit','Name']).sum(level=[0,1])
Out[175]: 
               Number
Fruit   Name         
Apples  Bob        16
        Mike        9
        Steve      10
Oranges Bob        67
        Tom        15
        Mike       57
        Tony        1
Grapes  Bob        35
        Tom        87
        Tony       15

Class has no initializers Swift

My answer addresses the error in general and not the exact code of the OP. No answer mentioned this note so I just thought I add it.

The code below would also generate the same error:

class Actor {
    let agent : String? // BAD! // Its value is set to nil, and will always be nil and that's stupid so Xcode is saying not-accepted.  
    // Technically speaking you have a way around it, you can help the compiler and enforce your value as a constant. See Option3
}

Others mentioned that Either you create initializers or you make them optional types, using ! or ? which is correct. However if you have an optional member/property, that optional should be mutable ie var. If you make a let then it would never be able to get out of its nil state. That's bad!

So the correct way of writing it is:

Option1

class Actor {
    var agent : String? // It's defaulted to `nil`, but also has a chance so it later can be set to something different || GOOD!
}

Or you can write it as:

Option2

class Actor {
let agent : String? // It's value isn't set to nil, but has an initializer || GOOD!

init (agent: String?){
    self.agent = agent // it has a chance so its value can be set!
    }
}

or default it to any value (including nil which is kinda stupid)

Option3

class Actor {
let agent : String? = nil // very useless, but doable.
let company: String? = "Universal" 
}

If you are curious as to why let (contrary to var) isn't initialized to nil then read here and here

What happened to the .pull-left and .pull-right classes in Bootstrap 4?

The classes are float-right float-sm-right etc.

The media queries are mobile-first, so using float-sm-right would affect small screen sizes and anything wider, so there's no reason to add a class for each width. Just use the smallest screen you want to affect or float-right for all screen widths.

Official Docs:

Classes: https://getbootstrap.com/docs/4.4/utilities/float/

Updating: https://getbootstrap.com/docs/4.4/migration/#utilities

If you are updating an existing project based on an earlier version of Bootstrap, you can use sass extend to apply the rules to the old class names:

.pull-right {
    @extend .float-right;
}
.pull-left {
    @extend .float-left;
}

Duplicate Entire MySQL Database

This worked for me with command prompt, from OUTSIDE mysql shell:

# mysqldump -u root -p password db1 > dump.sql
# mysqladmin -u root -p password create db2
# mysql -u root -p password db2 < dump.sql

This looks for me the best way. If zipping "dump.sql" you can symply store it as a compressed backup. Cool! For a 1GB database with Innodb tables, about a minute to create "dump.sql", and about three minutes to dump data into the new DB db2.

Straight copying the hole db directory (mysql/data/db1) didn't work for me, I guess because of the InnoDB tables.

Starting of Tomcat failed from Netbeans

Also, it is very likely, that problem with proxy settings.

Any who didn't overcome Tomact starting problrem, - try in NetBeans choose No Proxy in the Tools -> Options -> General tab.

It helped me.

Ionic 2: Cordova is not available. Make sure to include cordova.js or run in a device/simulator (running in emulator)

The livereload plugin fails to serve cordova.js file and serves // mock cordova file during development.

FIX: You need go to node_modules/@ionic/app-scripts/dist/dev-server/serve-config.js

and replace

exports.ANDROID_PLATFORM_PATH = path.join('platforms', 'android', 'assets', 'www');

to

exports.ANDROID_PLATFORM_PATH = path.join('platforms', 'android', 'app', 'src', 'main', 'assets', 'www');

Using Default Arguments in a Function

Pass an array to the function, instead of individual parameters and use null coalescing operator (PHP 7+).

Below, I'm passing an array with 2 items. Inside the function, I'm checking if value for item1 is set, if not assigned default vault.

$args = ['item2' => 'item2',
        'item3' => 'value3'];

    function function_name ($args) {
        isset($args['item1']) ? $args['item1'] : 'default value';
    }

When do you use Java's @Override annotation and why?

I use it as much as can to identify when a method is being overriden. If you look at the Scala programming language, they also have an override keyword. I find it useful.

Tracking changes in Windows registry

PhiLho has mentioned AutoRuns in passing, but I think it deserves elaboration.

It doesn't scan the whole registry, just the parts containing references to things which get loaded automatically (EXEs, DLLs, drivers etc.) which is probably what you are interested in. It doesn't track changes but can export to a text file, so you can run it before and after installation and do a diff.

How to enumerate an object's properties in Python?

for one-liners:

print vars(theObject)

Multiple values in single-value context

Yes, there is.

Surprising, huh? You can get a specific value from a multiple return using a simple mute function:

package main

import "fmt"
import "strings"

func µ(a ...interface{}) []interface{} {
    return a
}

type A struct {
    B string
    C func()(string)
}

func main() {
    a := A {
        B:strings.TrimSpace(µ(E())[1].(string)),
        C:µ(G())[0].(func()(string)),
    }

    fmt.Printf ("%s says %s\n", a.B, a.C())
}

func E() (bool, string) {
    return false, "F"
}

func G() (func()(string), bool) {
    return func() string { return "Hello" }, true
}

https://play.golang.org/p/IwqmoKwVm-

Notice how you select the value number just like you would from a slice/array and then the type to get the actual value.

You can read more about the science behind that from this article. Credits to the author.

how to read value from string.xml in android?

Details

  • Android Studio 3.1.4
  • Kotlin version: 1.2.60

Task

  • single line use
  • minimum code
  • use suggestions from the compiler

Step 1. Application()

Get link to the context of you application

class MY_APPLICATION_NAME: Application() {

    companion object {
        private lateinit var instance: MY_APPLICATION_NAME

        fun getAppContext(): Context = instance.applicationContext
    }

    override fun onCreate() {
        instance = this
        super.onCreate()
    }

}

Step 2. Add int extension

inline fun Int.toLocalizedString(): String = MY_APPLICATION_NAME.getAppContext().resources.getString(this)

Usage

strings.xml

<resources>
    <!-- .......  -->
    <string name="no_internet_connection">No internet connection</string>
    <!-- .......  -->
</resources>

Get string value:

val errorMessage = R.string.no_internet_connection.toLocalizedString()

Results

enter image description here enter image description here

How to position the Button exactly in CSS

So, the trick here is to use absolute positioning calc like this:

top: calc(50% - XYpx);
left: calc(50% - XYpx);

where XYpx is half the size of your image, in my case, the image was a square. Of course, in this now obsolete case, the image must also change its size proportionally in response to window resize to be able to remain at the center without looking out of proportion.

OS X Framework Library not loaded: 'Image not found'

I think there is no fixed way to solve this problem since it might be caused by different reason. I also had this problem last week, I don't know when and exactly what cause this problem, only when I run it on simulator with Xcode or try to install it onto the phone, then it reports such kind of error, But when I run it with react-native run-ios with terminal, there is no problem.

I checked all the ways posted on the internet, like renew certificate, change settings in Xcode (all of ways mentions above), actually all of settings in Xcode were already set as it requested before, none of ways works for me. Until this morning when I delete the pods and reinstall, the error finally gonna after a week. If you are also using cocoapod and then error was just show up without any specific reason, maybe you can try my way.

  1. Check my cocoapods version.
  2. Update it if there is new version available.
  3. Go to your project folder, delete your Podfile.lock , Pods file, project xcworkspace.
  4. Run pod install

Detect page change on DataTable

I got it working using:

$('#id-of-table').on('draw.dt', function() {
    // do action here
});

Marker content (infoWindow) Google Maps

Although this question has already been answered, I think this approach is better : http://jsfiddle.net/kjy112/3CvaD/ extract from this question on StackOverFlow google maps - open marker infowindow given the coordinates:

Each marker gets an "infowindow" entry :

function createMarker(lat, lon, html) {
    var newmarker = new google.maps.Marker({
        position: new google.maps.LatLng(lat, lon),
        map: map,
        title: html
    });

    newmarker['infowindow'] = new google.maps.InfoWindow({
            content: html
        });

    google.maps.event.addListener(newmarker, 'mouseover', function() {
        this['infowindow'].open(map, this);
    });
}

javascript remove "disabled" attribute from html input

method 1 <input type="text" onclick="this.disabled=false;" disabled>
<hr>
method 2 <input type="text" onclick="this.removeAttribute('disabled');" disabled>
<hr>
method 3 <input type="text" onclick="this.removeAttribute('readonly');" readonly>

code of the previous answers don't seem to work in inline mode, but there is a workaround: method 3.

see demo https://jsfiddle.net/eliz82/xqzccdfg/

PHP Function Comments

You can get the comments of a particular method by using the ReflectionMethod class and calling ->getDocComment().

http://www.php.net/manual/en/reflectionclass.getdoccomment.php

java.lang.ClassNotFoundException: Didn't find class on path: dexpathlist

One possible reason would be the incorrect path of the activity in the Apps AndroidManifest.xml file. Register the activity with in your AndroidManifest.xml with full relative path like below.

<activity android:name="<full_path>.ActivityName" />

SyntaxError: Unexpected Identifier in Chrome's Javascript console

Replace

 var myNewString = myOldString.replace ("username," visitorName);

with

 var myNewString = myOldString.replace("username", visitorName);

How to resize html canvas element?

This worked for me just now:

<canvas id="c" height="100" width="100" style="border:1px solid red"></canvas>
<script>
var c = document.getElementById('c');
alert(c.height + ' ' + c.width);
c.height = 200;
c.width = 200;
alert(c.height + ' ' + c.width);
</script>

Converting an object to a string

If you want a minimalist method of converting a variable to a string for an inline expression type situation, ''+variablename is the best I have golfed.

If 'variablename' is an object and you use the empty string concatenation operation, it will give the annoying [object Object], in which case you probably want Gary C.'s enormously upvoted JSON.stringify answer to the posted question, which you can read about on Mozilla's Developer Network at the link in that answer at the top.

Interface vs Abstract Class (general OO)

An interface defines a contract for a service or set of services. They provide polymorphism in a horizontal manner in that two completely unrelated classes can implement the same interface but be used interchangeably as a parameter of the type of interface they implement, as both classes have promised to satisfy the set of services defined by the interface. Interfaces provide no implementation details.

An abstract class defines a base structure for its sublcasses, and optionally partial implementation. Abstract classes provide polymorphism in a vertical, but directional manner, in that any class that inherits the abstract class can be treated as an instance of that abstract class but not the other way around. Abstract classes can and often do contain implementation details, but cannot be instantiated on their own- only their subclasses can be "newed up".

C# does allow for interface inheritance as well, mind you.

Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server."

Some times due to some code you get HTML tags in a text filed, like I was replacing some characters with new line BR tag of HTML and by mistake I also replaced it in the text that was supposed to be displayed in a Multiline text box so my multiline text box had a new line HTML tag BR in it coming dynamically due to my string replace function and I started getting this JavaScript error and as this HTML code was displayed in a text box that was in an update panel I start getting this error so I made the correction and all was fine. So before copying pasting anything please look at your code and see that all tag are closed proper and no irrelevant code data is coming to text boxes or Drop down lists. This error always come due to ill formed tags and irrelevant data.

How to create and show common dialog (Error, Warning, Confirmation) in JavaFX 2.0?

Adapted from answer here: https://stackoverflow.com/a/7505528/921224

javafx.scene.control.Alert

For a an in depth description of how to use JavaFX dialogs see: JavaFX Dialogs (official) by code.makery. They are much more powerful and flexible than Swing dialogs and capable of far more than just popping up messages.

import javafx.scene.control.Alert
import javafx.scene.control.Alert.AlertType;
import javafx.application.Platform;

public class ClassNameHere
{

    public static void infoBox(String infoMessage, String titleBar)
    {
        /* By specifying a null headerMessage String, we cause the dialog to
           not have a header */
        infoBox(infoMessage, titleBar, null);
    }

    public static void infoBox(String infoMessage, String titleBar, String headerMessage)
    {
        Alert alert = new Alert(AlertType.INFORMATION);
        alert.setTitle(titleBar);
        alert.setHeaderText(headerMessage);
        alert.setContentText(infoMessage);
        alert.showAndWait();
    }
}

One thing to keep in mind is that JavaFX is a single threaded GUI toolkit, which means this method should be called directly from the JavaFX application thread. If you have another thread doing work, which needs a dialog then see these SO Q&As: JavaFX2: Can I pause a background Task / Service? and Platform.Runlater and Task Javafx.

To use this method call:

ClassNameHere.infoBox("YOUR INFORMATION HERE", "TITLE BAR MESSAGE");

or

ClassNameHere.infoBox("YOUR INFORMATION HERE", "TITLE BAR MESSAGE", "HEADER MESSAGE");

MySQL foreign key constraints, cascade delete

I got confused by the answer to this question, so I created a test case in MySQL, hope this helps

-- Schema
CREATE TABLE T1 (
    `ID` int not null auto_increment,
    `Label` varchar(50),
    primary key (`ID`)
);

CREATE TABLE T2 (
    `ID` int not null auto_increment,
    `Label` varchar(50),
    primary key (`ID`)
);

CREATE TABLE TT (
    `IDT1` int not null,
    `IDT2` int not null,
    primary key (`IDT1`,`IDT2`)
);

ALTER TABLE `TT`
    ADD CONSTRAINT `fk_tt_t1` FOREIGN KEY (`IDT1`) REFERENCES `T1`(`ID`) ON DELETE CASCADE,
    ADD CONSTRAINT `fk_tt_t2` FOREIGN KEY (`IDT2`) REFERENCES `T2`(`ID`) ON DELETE CASCADE;

-- Data
INSERT INTO `T1` (`Label`) VALUES ('T1V1'),('T1V2'),('T1V3'),('T1V4');
INSERT INTO `T2` (`Label`) VALUES ('T2V1'),('T2V2'),('T2V3'),('T2V4');
INSERT INTO `TT` (`IDT1`,`IDT2`) VALUES
(1,1),(1,2),(1,3),(1,4),
(2,1),(2,2),(2,3),(2,4),
(3,1),(3,2),(3,3),(3,4),
(4,1),(4,2),(4,3),(4,4);

-- Delete
DELETE FROM `T2` WHERE `ID`=4; -- Delete one field, all the associated fields on tt, will be deleted, no change in T1
TRUNCATE `T2`; -- Can't truncate a table with a referenced field
DELETE FROM `T2`; -- This will do the job, delete all fields from T2, and all associations from TT, no change in T1

Converting a string to a date in JavaScript

new Date(2000, 10, 1) will give you "Wed Nov 01 2000 00:00:00 GMT+0100 (CET)"

See that 0 for month gives you January

How to remove MySQL completely with config and library files?

Just a little addition to the answer of @dAm2k :

In addition to sudo apt-get remove --purge mysql\*

I've done a sudo apt-get remove --purge mariadb\*.

I seems that in the new release of debian (stretch), when you install mysql it install mariadb package with it.

Hope it helps.

Using the passwd command from within a shell script

The only solution works on Ubuntu 12.04:

echo -e "new_password\nnew_password" | (passwd user)

But the second option only works when I change from:

echo "password:name" | chpasswd

To:

echo "user:password" | chpasswd

See explanations in original post: Changing password via a script

Call child method from parent

you can use ref to call the function of the child component from the parent

Functional Component Solution

in functional component, you have to use useImperativeHandle for getting ref into a child like below

import React, { forwardRef, useRef, useImperativeHandle } from 'react';
export default function ParentFunction() {
    const childRef = useRef();
    return (
        <div className="container">
            <div>
                Parent Component
            </div>
            <button
                onClick={() => { childRef.current.showAlert() }}
            >
            Call Function
            </button>
            <Child ref={childRef}/>
        </div>
    )
}
const Child = forwardRef((props, ref) => {
    useImperativeHandle(
        ref,
        () => ({
            showAlert() {
                alert("Child Function Called")
            }
        }),
    )
    return (
       <div>Child Component</div>
    )
})

Class Component Solution

Child.js

import s from './Child.css';

class Child extends Component {
 getAlert() {
    alert('clicked');
 }
 render() {
  return (
    <h1>Hello</h1>
  );
 }
}

export default Child;

Parent.js

class Parent extends Component {
 render() {
  onClick() {
    this.refs.child.getAlert();
  }
  return (
    <div>
      <Child ref="child" />
      <button onClick={this.onClick}>Click</button>
    </div>
  );
 }
}

Real world use of JMS/message queues?

I have seen JMS used in different commercial and academic projects. JMS can easily come into your picture, whenever you want to have a totally decoupled distributed systems. Generally speaking, when you need to send your request from one node, and someone in your network takes care of it without/with giving the sender any information about the receiver.

In my case, I have used JMS in developing a message-oriented middleware (MOM) in my thesis, where specific types of object-oriented objects are generated in one side as your request, and compiled and executed on the other side as your response.

Python integer incrementing with ++

Simply put, the ++ and -- operators don't exist in Python because they wouldn't be operators, they would have to be statements. All namespace modification in Python is a statement, for simplicity and consistency. That's one of the design decisions. And because integers are immutable, the only way to 'change' a variable is by reassigning it.

Fortunately we have wonderful tools for the use-cases of ++ and -- in other languages, like enumerate() and itertools.count().

POST JSON to API using Rails and HTTParty

I solved this by adding .to_json and some heading information

@result = HTTParty.post(@urlstring_to_post.to_str, 
    :body => { :subject => 'This is the screen name', 
               :issue_type => 'Application Problem', 
               :status => 'Open', 
               :priority => 'Normal', 
               :description => 'This is the description for the problem'
             }.to_json,
    :headers => { 'Content-Type' => 'application/json' } )

Remove warning messages in PHP

You can put an @ in front of your function call to suppress all error messages.

@yourFunctionHere();

PHP header(Location: ...): Force URL change in address bar

use

header("Location: index.php"); //this work in my site

read more on header() at php documentation.

Jenkins Git Plugin: How to build specific tag?

I was able to do that by using the "branches to build" parameter:

Branch Specifier (blank for default): tags/[tag-name]

Replace [tag-name] by the name of your tag.

How do I replace a double-quote with an escape-char double-quote in a string using JavaScript?

var str = 'Dude, he totally said that "You Rock!"';
var var1 = str.replace(/\"/g,"\\\"");
alert(var1);

browser.msie error after update to jQuery 1.9.1

You can detect the IE browser by this way.

(navigator.userAgent.toLowerCase().indexOf('msie 6') != -1)

you can get reference on this URL: jquery.browser.msie Alternative

What is the most efficient way to create a dictionary of two pandas Dataframe columns?

I found a faster way to solve the problem, at least on realistically large datasets using: df.set_index(KEY).to_dict()[VALUE]

Proof on 50,000 rows:

df = pd.DataFrame(np.random.randint(32, 120, 100000).reshape(50000,2),columns=list('AB'))
df['A'] = df['A'].apply(chr)

%timeit dict(zip(df.A,df.B))
%timeit pd.Series(df.A.values,index=df.B).to_dict()
%timeit df.set_index('A').to_dict()['B']

Output:

100 loops, best of 3: 7.04 ms per loop  # WouterOvermeire
100 loops, best of 3: 9.83 ms per loop  # Jeff
100 loops, best of 3: 4.28 ms per loop  # Kikohs (me)

How to pass prepareForSegue: an object

I have a sender class, like this

@class MyEntry;

@interface MySenderEntry : NSObject
@property (strong, nonatomic) MyEntry *entry;
@end

@implementation MySenderEntry
@end

I use this sender class for passing objects to prepareForSeque:sender:

-(void)didSelectItemAtIndexPath:(NSIndexPath*)indexPath
{
    MySenderEntry *sender = [MySenderEntry new];
    sender.entry = [_entries objectAtIndex:indexPath.row];
    [self performSegueWithIdentifier:SEGUE_IDENTIFIER_SHOW_ENTRY sender:sender];
}

-(void)prepareForSegue:(UIStoryboardSegue*)segue sender:(id)sender
{
    if ([[segue identifier] isEqualToString:SEGUE_IDENTIFIER_SHOW_ENTRY]) {
        NSAssert([sender isKindOfClass:[MySenderEntry class]], @"MySenderEntry");
        MySenderEntry *senderEntry = (MySenderEntry*)sender;
        MyEntry *entry = senderEntry.entry;
        NSParameterAssert(entry);

        [segue destinationViewController].delegate = self;
        [segue destinationViewController].entry = entry;
        return;
    }

    if ([[segue identifier] isEqualToString:SEGUE_IDENTIFIER_HISTORY]) {
        // ...
        return;
    }

    if ([[segue identifier] isEqualToString:SEGUE_IDENTIFIER_FAVORITE]) {
        // ...
        return;
    }
}

Using column alias in WHERE clause of MySQL query produces an error

Standard SQL (or MySQL) does not permit the use of column aliases in a WHERE clause because

when the WHERE clause is evaluated, the column value may not yet have been determined.

(from MySQL documentation). What you can do is calculate the column value in the WHERE clause, save the value in a variable, and use it in the field list. For example you could do this:

SELECT `users`.`first_name`, `users`.`last_name`, `users`.`email`,
@postcode AS `guaranteed_postcode`
FROM `users` LEFT OUTER JOIN `locations`
ON `users`.`id` = `locations`.`user_id`
WHERE (@postcode := SUBSTRING(`locations`.`raw`,-6,4)) NOT IN
(
 SELECT `postcode` FROM `postcodes` WHERE `region` IN
 (
  'australia'
 )
)

This avoids repeating the expression when it grows complicated, making the code easier to maintain.

Should I use <i> tag for icons instead of <span>?

I'm jumping in here a little late, but came across this page when pondering it myself. Of course I don't know how Facebook or Twitter justified it, but here is my own thought process for what it's worth.

In the end, I concluded that this practice is not that unsemantic (is that a word?). In fact, besides shortness and the nice association of "i is for icon," I think it's actually the most semantic choice for an icon when a straightforward <img> tag is not practical.

1. The usage is consistent with the spec.

While it may not be what the W3 mainly had in mind, it seems to me the official spec for <i> could accommodate an icon pretty easily. After all, the reply-arrow symbol is saying "reply" in another way. It expresses a technical term that may be unfamiliar to the reader and would be typically italicized. ("Here at Twitter, this is what we call a reply arrow.") And it is a term from another language: a symbolic language.

If, instead of the arrow symbol, Twitter used <i>shout out</i> or <i>[Japanese character for reply]</i> (on an English page), that would be consistent with the spec. Then why not <i>[reply arrow]</i>? (I'm talking strictly HTML semantics here, not accessibility, which I'll get to.)

As far as I can see, the only part of the spec explicitly violated by icon usage is the "span of text" phrase (when the tag doesn't contain text also). It is clear that the <i> tag is mainly meant for text, but that's a pretty small detail compared with the overall intent of the tag. The important question for this tag is not what format of content it contains, but what the meaning of that content is.

This is especially true when you consider that the line between "text" and "icon" can be almost nonexistent on websites. Text may look like more like an icon (as in the Japanese example) or an icon may look like text (as in a jpg button that says "Submit" or a cat photo with an overlaid caption) or text may be replaced or enhanced with an image via CSS. Text, image - who cares? It's all content. As long as everyone - humans with impairments, browsers with impairments, search engine spiders, and other machines of various kinds can understand that meaning, we've done our job.

So the fact that the writers of the spec didn't think (or choose) to clarify this shouldn't tie our hands from doing what makes sense and is consistent with the spirit of the tag. The <a> tag was originally intended to take the user somewhere else, but now it might pop up a lightbox. Big whoop, right? If someone had figured out how to pop up a lightbox on click before the spec caught up, they still should have used the <a> tag, not a <span>, even if it wasn't entirely consistent with the current definition - because it came the closest and was still consistent with the spirit of the tag ("something will happen when you click here"). Same deal with <i> - whatever type of thing you put inside it, or however creatively you use it, it expresses the general idea of an alternate or set-apart term.

2. The <i> tag adds semantic meaning to an icon element.

The alternative option to carry an icon class by itself is <span>, which of course has no semantic meaning whatsoever. When a machine asks the <span> what it contains, it says, "I don't know. Could be anything." But the <i> tag says, "I contain a different way of saying something than the usual way, or maybe an unfamiliar term." That's not the same as "I contain an icon," but it's a lot closer to it than <span> got!

3. Eventually, common usage makes right.

In addition to the above, it's worth considering that machine readers (whether search engine, screen reader, or whatever) may at any time begin to take into account that Facebook, Twitter, and other websites use the <i> tag for icons. They don't care about the spec as much as they care about extracting meaning from code by whatever means necessary. So they might use this knowledge of common usage to simply record that "there may be an icon here" or do something more advanced like triggering a look into the CSS for a hint to meaning, or who knows what. So if you choose to use the <i> for icons on your website, you may be providing more meaning than the spec does.

Moreover, if this usage becomes widespread, it will likely be included in the spec in the future. Then you'll be going through your code, replacing <span>s with <i>'s! So it may make sense to get on board with what seems to be the direction of the spec, especially when it doesn't clearly conflict with the current spec. Common usage tends to dictate language rules more than the other way around. If you're old enough, do you remember that "Web site" was the official spelling when the word was new? Dictionaries insisted there must be a space and Web must be capitalized. There were semantic reasons for that. But common usage said, "Whatever, that's stupid. I'm using 'website' because it's more concise and looks better." And before long, dictionaries officially acknowledged that spelling as correct.

4. So I'm going ahead and using it.

So, <i> provides more meaning to machines because of the spec, it provides more meaning to humans because we easily associate "i" with "icon", and it's only one letter long. Win! And if you make sure to include equivalent text either inside the <i> tag or right next to it (as Twitter does), then screen readers understand where to click to reply, the link is usable if CSS doesn't load, and human readers with good eyesight and a decent browser see a pretty icon. With all this in mind, I don't see the downside.

get the latest fragment in backstack

Keep your own back stack: myBackStack. As you Add a fragment to the FragmentManager, also add it to myBackStack. In onBackStackChanged() pop from myBackStack when its length is greater than getBackStackEntryCount.

Adjust table column width to content size

The problem was the table width. I had used width: 100% for the table. The table columns are adjusted automatically after removing the width tag.

Cannot declare instance members in a static class in C#

As John Weldon said all members must be static in a static class. Try

public static class employee
{
     static NameValueCollection appSetting = ConfigurationManager.AppSettings;    

}

How do you format the day of the month to say "11th", "21st" or "23rd" (ordinal indicator)?

Here is an approach that updates a DateTimeFormatter pattern with the correct suffix literal if it finds the pattern d'00', e.g. for day of month 1 it would be replaced with d'st'. Once the pattern has been updated it can then just be fed into the DateTimeFormatter to do the rest.

private static String[] suffixes = {"th", "st", "nd", "rd"};

private static String updatePatternWithDayOfMonthSuffix(TemporalAccessor temporal, String pattern) {
    String newPattern = pattern;
    // Check for pattern `d'00'`.
    if (pattern.matches(".*[d]'00'.*")) {
        int dayOfMonth = temporal.get(ChronoField.DAY_OF_MONTH);
        int relevantDigits = dayOfMonth < 30 ? dayOfMonth % 20 : dayOfMonth % 30;
        String suffix = suffixes[relevantDigits <= 3 ? relevantDigits : 0];
        newPattern = pattern.replaceAll("[d]'00'", "d'" + suffix + "'");
    }

    return newPattern;
}

It does require that the original pattern is updated just prior to every formatting call, e.g.

public static String format(TemporalAccessor temporal, String pattern) {
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern(updatePatternWithDayOfMonthSuffix(temporal, pattern));
    return formatter.format(temporal);
}

So this is useful if the formatting pattern is defined outside of Java code, e.g. a template, where as if you can define the pattern in Java then the answer by @OleV.V. might be more appropriate

Get Line Number of certain phrase in file Python

listStr = open("file_name","mode")

if "search element" in listStr:
    print listStr.index("search element")  # This will gives you the line number

Merging cells in Excel using Apache POI

You can use :

sheet.addMergedRegion(new CellRangeAddress(startRowIndx, endRowIndx, startColIndx,endColIndx));

Make sure the CellRangeAddress does not coincide with other merged regions as that will throw an exception.

  • If you want to merge cells one above another, keep column indexes same
  • If you want to merge cells which are in a single row, keep the row indexes same
  • Indexes are zero based

For what you were trying to do this should work:

sheet.addMergedRegion(new CellRangeAddress(rowNo, rowNo, 0, 3));

JQuery Validate Dropdown list

    <div id="msg"></div>
<!-- put above tag on body to see selected value or error -->
<script>
    $(function(){
        $("#HoursEntry").change(function(){
            var HoursEntry = $("#HoursEntry option:selected").val();
            console.log(HoursEntry);
            if(HoursEntry == "")
            {
                $("#msg").html("Please select at least One option");
                return false;
            }
            else
            {
                $("#msg").html("selected val is  "+HoursEntry);
            }
        });
    });
</script>

change figure size and figure format in matplotlib

You can change the size of the plot by adding this before you create the figure.

plt.rcParams["figure.figsize"] = [16,9]

Git - How to fix "corrupted" interactive rebase?

I'm using git version 2.19.2.windows.1.

the only thing that worked for me was to remove the .git/rebase-apply/ directory and do a git reset --hard.

How can I create an utility class?

I would make the class final and every method would be static.

So the class cannot be extended and the methods can be called by Classname.methodName. If you add members, be sure that they work thread safe ;)

How to convert a byte array to Stream

In your case:

MemoryStream ms = new MemoryStream(buffer);

get dictionary value by key

That is not how the TryGetValue works. It returns true or false based on whether the key is found or not, and sets its out parameter to the corresponding value if the key is there.

If you want to check if the key is there or not and do something when it's missing, you need something like this:

bool hasValue = Data_Array.TryGetValue("XML_File", out value);
if (hasValue) {
    xmlfile = value;
} else {
    // do something when the value is not there
}

PDF to image using Java

jPDFImages is not free but a commercial library which converts PDF pages to images in JPEG, TIFF or PNG format. The output image size is customizable.

How to hide a div after some time period?

_x000D_
_x000D_
$().ready(function(){_x000D_
_x000D_
  $('div.alert').delay(1500);_x000D_
   $('div.alert').hide(1000);_x000D_
});
_x000D_
div.alert{_x000D_
color: green;_x000D_
background-color: rgb(50,200,50, .5);_x000D_
padding: 10px;_x000D_
text-align: center;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<div class="alert"><p>Inserted Successfully . . .</p></div>
_x000D_
_x000D_
_x000D_

jQuery .load() call doesn't execute JavaScript in loaded HTML file

You've almost got it. Tell jquery you want to load only the script:

$("#myBtn").click(function() {
    $("#myDiv").load("trackingCode.html script");
});

How to create a css rule for all elements except one class?

The safest bet is to create a class on those tables and use that. Currently getting something like this to work in all major browsers is unlikely.

What is the best comment in source code you have ever encountered?

Best comment I ever saw was

/* 
  There is no accounting for pointers 
*/

How to rollback just one step using rake db:migrate

  try {
        $result=DB::table('users')->whereExists(function ($Query){
            $Query->where('id','<','14162756');
            $Query->whereBetween('password',[14162756,48384486]);
            $Query->whereIn('id',[3,8,12]);
        });
    }catch (\Exception $error){
        Log::error($error);
        DB::rollBack(1);
        return redirect()->route('bye');
    }

Group query results by month and year in postgresql

I can't believe the accepted answer has so many upvotes -- it's a horrible method.

Here's the correct way to do it, with date_trunc:

   SELECT date_trunc('month', txn_date) AS txn_month, sum(amount) as monthly_sum
     FROM yourtable
 GROUP BY txn_month

It's bad practice but you might be forgiven if you use

 GROUP BY 1

in a very simple query.

You can also use

 GROUP BY date_trunc('month', txn_date)

if you don't want to select the date.

Pandas groupby month and year

You can use either resample or Grouper (which resamples under the hood).

First make sure that the datetime column is actually of datetimes (hit it with pd.to_datetime). It's easier if it's a DatetimeIndex:

In [11]: df1
Out[11]:
            abc  xyz
Date
2013-06-01  100  200
2013-06-03  -20   50
2013-08-15   40   -5
2014-01-20   25   15
2014-02-21   60   80

In [12]: g = df1.groupby(pd.Grouper(freq="M"))  # DataFrameGroupBy (grouped by Month)

In [13]: g.sum()
Out[13]:
            abc  xyz
Date
2013-06-30   80  250
2013-07-31  NaN  NaN
2013-08-31   40   -5
2013-09-30  NaN  NaN
2013-10-31  NaN  NaN
2013-11-30  NaN  NaN
2013-12-31  NaN  NaN
2014-01-31   25   15
2014-02-28   60   80

In [14]: df1.resample("M", how='sum')  # the same
Out[14]:
            abc  xyz
Date
2013-06-30   40  125
2013-07-31  NaN  NaN
2013-08-31   40   -5
2013-09-30  NaN  NaN
2013-10-31  NaN  NaN
2013-11-30  NaN  NaN
2013-12-31  NaN  NaN
2014-01-31   25   15
2014-02-28   60   80

Note: Previously pd.Grouper(freq="M") was written as pd.TimeGrouper("M"). The latter is now deprecated since 0.21.


I had thought the following would work, but it doesn't (due to as_index not being respected? I'm not sure.). I'm including this for interest's sake.

If it's a column (it has to be a datetime64 column! as I say, hit it with to_datetime), you can use the PeriodIndex:

In [21]: df
Out[21]:
        Date  abc  xyz
0 2013-06-01  100  200
1 2013-06-03  -20   50
2 2013-08-15   40   -5
3 2014-01-20   25   15
4 2014-02-21   60   80

In [22]: pd.DatetimeIndex(df.Date).to_period("M")  # old way
Out[22]:
<class 'pandas.tseries.period.PeriodIndex'>
[2013-06, ..., 2014-02]
Length: 5, Freq: M

In [23]: per = df.Date.dt.to_period("M")  # new way to get the same

In [24]: g = df.groupby(per)

In [25]: g.sum()  # dang not quite what we want (doesn't fill in the gaps)
Out[25]:
         abc  xyz
2013-06   80  250
2013-08   40   -5
2014-01   25   15
2014-02   60   80

To get the desired result we have to reindex...

PHP Parse error: syntax error, unexpected end of file in a CodeIgniter View

Unexpected end of file means that something else was expected before the PHP parser reached the end of the script.

Judging from your HUGE file, it's probably that you're missing a closing brace (}) from an if statement.

Please at least attempt the following things:

  1. Separate your code from your view logic.
  2. Be consistent, you're using an end ; in some of your embedded PHP statements, and not in others, ie. <?php echo base_url(); ?> vs <?php echo $this->layouts->print_includes() ?>. It's not required, so don't use it (or do, just do one or the other).
  3. Repeated because it's important, separate your concerns. There's no need for all of this code.
  4. Use an IDE, it will help you with errors such as this going forward.

Convert regular Python string to raw string

Just format like that:

s = "your string"; raw_s = r'{0}'.format(s)

Jquery Date picker Default Date

Use the defaultDate option

$( ".selector" ).datepicker({ defaultDate: '01/01/01' });

If you change your date format, make sure to change the input into defaultDate (e.g. '01-01-2001')

Turn off auto formatting in Visual Studio

In my case, it was ReSharper.

Test if ReSharper

StackOverflow: How can I disable ReSharper in Visual Studio and enable it again?

Prevent ReSharper from reformatting code

StackOverflow: Is there a way to mark up code to tell ReSharper not to format it?

Update 2017-03-01

It was ReSharper in the end:

enter image description here

Update 2020-12-18

On the latest version of ReSharper, there are more options: untick everything on this page, and ensure all dropdowns are set to the equivalent of None.

ReSharper "typing assist" is like a 3-year-old trying to "help" build a card castle. A simple backspace or an enter key will (poorly) reformat entire blocks of code, requiring it to be undone or painfully formatted back to the original.

And if that is not enough, this is the bit that adds delays when typing so sometimes it feels like trying to run in skis.

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

You can wrap it in your own function:

function isNullAndUndef(variable) {

    return (variable !== null && variable !== undefined);
}

How to find whether MySQL is installed in Red Hat?

Type mysql --version to see if it is installed.

To find location use find -name mysql.

Set specific precision of a BigDecimal

 BigDecimal decPrec = (BigDecimal)yo.get("Avg");
 decPrec = decPrec.setScale(5, RoundingMode.CEILING);
 String value= String.valueOf(decPrec);

This way you can set specific precision of a BigDecimal.

The value of decPrec was 1.5726903423607562595809913132345426 which is rounded off to 1.57267.

Compare two Lists for differences

I hope that I am understing your question correctly, but you can do this very quickly with Linq. I'm assuming that universally you will always have an Id property. Just create an interface to ensure this.

If how you identify an object to be the same changes from class to class, I would recommend passing in a delegate that returns true if the two objects have the same persistent id.

Here is how to do it in Linq:

List<Employee> listA = new List<Employee>();
        List<Employee> listB = new List<Employee>();

        listA.Add(new Employee() { Id = 1, Name = "Bill" });
        listA.Add(new Employee() { Id = 2, Name = "Ted" });

        listB.Add(new Employee() { Id = 1, Name = "Bill Sr." });
        listB.Add(new Employee() { Id = 3, Name = "Jim" });

        var identicalQuery = from employeeA in listA
                             join employeeB in listB on employeeA.Id equals employeeB.Id
                             select new { EmployeeA = employeeA, EmployeeB = employeeB };

        foreach (var queryResult in identicalQuery)
        {
            Console.WriteLine(queryResult.EmployeeA.Name);
            Console.WriteLine(queryResult.EmployeeB.Name);
        }

How to write super-fast file-streaming code in C#?

How large is length? You may do better to re-use a fixed sized (moderately large, but not obscene) buffer, and forget BinaryReader... just use Stream.Read and Stream.Write.

(edit) something like:

private static void copy(string srcFile, string dstFile, int offset,
     int length, byte[] buffer)
{
    using(Stream inStream = File.OpenRead(srcFile))
    using (Stream outStream = File.OpenWrite(dstFile))
    {
        inStream.Seek(offset, SeekOrigin.Begin);
        int bufferLength = buffer.Length, bytesRead;
        while (length > bufferLength &&
            (bytesRead = inStream.Read(buffer, 0, bufferLength)) > 0)
        {
            outStream.Write(buffer, 0, bytesRead);
            length -= bytesRead;
        }
        while (length > 0 &&
            (bytesRead = inStream.Read(buffer, 0, length)) > 0)
        {
            outStream.Write(buffer, 0, bytesRead);
            length -= bytesRead;
        }
    }        
}

Getting the source HTML of the current page from chrome extension

Here is my solution:

chrome.runtime.onMessage.addListener(function(request, sender) {
        if (request.action == "getSource") {
            this.pageSource = request.source;
            var title = this.pageSource.match(/<title[^>]*>([^<]+)<\/title>/)[1];
            alert(title)
        }
    });

    chrome.tabs.query({ active: true, currentWindow: true }, tabs => {
        chrome.tabs.executeScript(
            tabs[0].id,
            { code: 'var s = document.documentElement.outerHTML; chrome.runtime.sendMessage({action: "getSource", source: s});' }
        );
    });

How to print object array in JavaScript?

You can just use the following syntax and the object will be fully shown in the console:

console.log('object evt: %O', object);

I use Chrome browser don't know if this is adaptable for other browsers.

process.env.NODE_ENV is undefined

In macOS for those who are using the express version 4.x.x and using the DOTENV plugin, need to use like this:

  1. After installing the plugin import like the following in the file where you init the application: require('dotenv').config({path: path.resolve(__dirname+'/.env')});

  2. In the root directory create a file '.env' and add the varaiable like:

    NODE_ENV=development or NODE_ENV = development

Align text in a table header

In HTML5, the easiest, and fastest, way to center your <th>THcontent</th> is to add a colspan like this:

<th colspan="3">Thcontent</th> 

This will work if your table is three columns. So if you have a four-column table, add a colspan of 4, etc.

You can manage the location furthermore in the CSS file while you have put your colspan in HTML like I said.

th { 
    text-align: center; /* Or right or left */
}

Copy directory to another directory using ADD command

Indeed ADD go /usr/local/ will add content of go folder and not the folder itself, you can use Thomasleveil solution or if that did not work for some reason you can change WORKDIR to /usr/local/ then add your directory to it like:

WORKDIR /usr/local/
COPY go go/

or

WORKDIR /usr/local/go
COPY go ./

But if you want to add multiple folders, it will be annoying to add them like that, the only solution for now as I see it from my current issue is using COPY . . and exclude all unwanted directories and files in .dockerignore, let's say I got folders and files:

- src 
- tmp 
- dist 
- assets 
- go 
- justforfun 
- node_modules 
- scripts 
- .dockerignore 
- Dockerfile 
- headache.lock 
- package.json 

and I want to add src assets package.json justforfun go so:

in Dockerfile:

FROM galaxy:latest

WORKDIR /usr/local/
COPY . .

in .dockerignore file:

node_modules
headache.lock
tmp
dist

Or for more fun (or you like to confuse more people make them suffer as well :P) can be:

*
!src 
!assets 
!go 
!justforfun 
!scripts 
!package.json 

In this way you ignore everything, but excluding what you want to be copied or added only from "ignore list".

It is a late answer but adding more ways to do the same covering even more cases.

How to escape a while loop in C#

If you need to continue with additional logic use...

break;

or if you have a value to return...

return my_value_to_be_returned;

However, looking at your code, I believe you will control the loop with the revised example below without using a break or return...

private void CheckLog()
        {
            bool continueLoop = true;
            while (continueLoop)
            {
                Thread.Sleep(5000);
                if (!System.IO.File.Exists("Command.bat")) continue;
                using (System.IO.StreamReader sr = System.IO.File.OpenText("Command.bat"))
                {
                    string s = "";
                    while (continueLoop && (s = sr.ReadLine()) != null)
                    {
                        if (s.Contains("mp4:production/CATCHUP/"))
                        {
                            RemoveEXELog();

                            Process p = new Process();
                            p.StartInfo.WorkingDirectory = "dump";
                            p.StartInfo.FileName = "test.exe"; 
                            p.StartInfo.Arguments = s; 
                            p.Start();
                            continueLoop = false;
                        }
                    }
                }
            }
        }

Error starting Tomcat from NetBeans - '127.0.0.1*' is not recognized as an internal or external command

I didnt try Sumama Waheed's answer but what worked for me was replacing the bin/catalina.jar with a working jar (I disposed of an older tomcat) and after adding in NetBeans, I put the original catalina.jar again.

What is the correct way to write HTML using Javascript?

The document.write method is very limited. You can only use it before the page has finished loading. You can't use it to update the contents of a loaded page.

What you probably want is innerHTML.

Add a duration to a moment (moment.js)

I am working on an application in which we track live route. Passenger wants to show current position of driver and the expected arrival time to reach at his/her location. So I need to add some duration into current time.

So I found the below mentioned way to do the same. We can add any duration(hour,minutes and seconds) in our current time by moment:

var travelTime = moment().add(642, 'seconds').format('hh:mm A');// it will add 642 seconds in the current time and will give time in 03:35 PM format

var travelTime = moment().add(11, 'minutes').format('hh:mm A');// it will add 11 mins in the current time and will give time in 03:35 PM format; can use m or minutes 

var travelTime = moment().add(2, 'hours').format('hh:mm A');// it will add 2 hours in the current time and will give time in 03:35 PM format

It fulfills my requirement. May be it can help you.

How to use border with Bootstrap

You can't just add a border to the span because it will break the layout because of the way width is calculate: width = border + padding + width. Since the container is 940px and the span is 940px, adding 2px border (so 4px altogether) will make it look off centered. The work around is to change the width to include the 4px border (original - 4px) or have another div inside that creates the 2px border.

Google Chrome redirecting localhost to https

Tried everything mentioned (browser preferences, hsts, etc.) but nothing worked for me.

I solved it by adding a trailing .localhost to the host aliases.

Like this:

127.0.0.1    myproject.localhost
127.0.0.1    dev.project.localhost

How to find length of a string array?

I think you are looking for this

String[] car = new String[10];
int size = car.length;

How to run TestNG from command line

You need to have the testng.jar under classpath.

try C:\projectfred> java -cp "path-tojar/testng.jar:path_to_yourtest_classes" org.testng.TestNG testng.xml

Update:

Under linux I ran this command and it would be some thing similar on Windows either

test/bin# java -cp ".:../lib/*" org.testng.TestNG testng.xml

Directory structure:

/bin - All my test packages are under bin including testng.xml
/src - All source files are under src
/lib - All libraries required for the execution of tests are under this.

Once I compile all sources they go under bin directory. So, in the classpath I need to specify contents of bin directory and all the libraries like testng.xml, loggers etc over here. Also copy testng.xml to bin folder if you dont want to specify the full path where the testng.xml is available.

 /bin
    -- testng.xml
    -- testclasses
    -- Properties files if any.
 /lib
    -- testng.jar
    -- log4j.jar

Update:

Go to the folder MyProject and type run the java command like the way shown below:-

java -cp ".: C:\Program Files\jbdevstudio4\studio\plugins\*" org.testng.TestNG testng.xml

I believe the testng.xml file is under C:\Users\me\workspace\MyProject if not please give the full path for testng.xml file

What's the difference between an argument and a parameter?

When we create the method (function) in Java, the method like this..

data-type name of the method (data-type variable-name)

In the parenthesis, these are the parameters, and when we call the method (function) we pass the value of this parameter, which are called the arguments.

MySQL Stored procedure variables from SELECT statements

You simply need to enclose your SELECT statements in parentheses to indicate that they are subqueries:

SET cityLat = (SELECT cities.lat FROM cities WHERE cities.id = cityID);

Alternatively, you can use MySQL's SELECT ... INTO syntax. One advantage of this approach is that both cityLat and cityLng can be assigned from a single table-access:

SELECT lat, lng INTO cityLat, cityLng FROM cities WHERE id = cityID;

However, the entire procedure can be replaced with a single self-joined SELECT statement:

SELECT   b.*, HAVERSINE(a.lat, a.lng, b.lat, b.lng) AS dist
FROM     cities AS a, cities AS b
WHERE    a.id = cityID
ORDER BY dist
LIMIT    10;

Visual studio code CSS indentation and formatting

Install HookyQR.beautify extension. It will beautify your javascript, JSON, CSS, Sass, and HTML in Visual Studio Code. It is the most use extensions for this purpose

What is the correct Performance Counter to get CPU and Memory Usage of a Process?

From this post:

To get the entire PC CPU and Memory usage:

using System.Diagnostics;

Then declare globally:

private PerformanceCounter theCPUCounter = 
   new PerformanceCounter("Processor", "% Processor Time", "_Total"); 

Then to get the CPU time, simply call the NextValue() method:

this.theCPUCounter.NextValue();

This will get you the CPU usage

As for memory usage, same thing applies I believe:

private PerformanceCounter theMemCounter = 
   new PerformanceCounter("Memory", "Available MBytes");

Then to get the memory usage, simply call the NextValue() method:

this.theMemCounter.NextValue();

For a specific process CPU and Memory usage:

private PerformanceCounter theCPUCounter = 
   new PerformanceCounter("Process", "% Processor Time",              
   Process.GetCurrentProcess().ProcessName);

where Process.GetCurrentProcess().ProcessName is the process name you wish to get the information about.

private PerformanceCounter theMemCounter = 
   new PerformanceCounter("Process", "Working Set",
   Process.GetCurrentProcess().ProcessName);

where Process.GetCurrentProcess().ProcessName is the process name you wish to get the information about.

Note that Working Set may not be sufficient in its own right to determine the process' memory footprint -- see What is private bytes, virtual bytes, working set?

To retrieve all Categories, see Walkthrough: Retrieving Categories and Counters

The difference between Processor\% Processor Time and Process\% Processor Time is Processor is from the PC itself and Process is per individual process. So the processor time of the processor would be usage on the PC. Processor time of a process would be the specified processes usage. For full description of category names: Performance Monitor Counters

An alternative to using the Performance Counter

Use System.Diagnostics.Process.TotalProcessorTime and System.Diagnostics.ProcessThread.TotalProcessorTime properties to calculate your processor usage as this article describes.

How do I clone a specific Git branch?

To clone a branch without fetching other branches:

mkdir $BRANCH
cd $BRANCH
git init
git remote add -t $BRANCH -f origin $REMOTE_REPO
git checkout $BRANCH

How can I get stock quotes using Google Finance API?

Here is an example that you can use. Havent got Google Finance yet, but Here is the Yahoo Example. You will need the HTMLAgilityPack , Which is awesome. Happy Symbol Hunting.

Call the procedure by using YahooStockRequest(string Symbols);

Where Symbols = a comma-delimited string of symbols, or just one symbol

public string YahooStockRequest(string Symbols,bool UseYahoo=true)
        {
            {
                string StockQuoteUrl = string.Empty;

                try
                {
                    // Use Yahoo finance service to download stock data from Yahoo
                    if (UseYahoo)
                    {
                        string YahooSymbolString = Symbols.Replace(",","+");
                        StockQuoteUrl = @"http://finance.yahoo.com/q?s=" + YahooSymbolString + "&ql=1";
                    }
                    else
                    {
                        //Going to Put Google Finance here when I Figure it out.
                    }

                    // Initialize a new WebRequest.
                    HttpWebRequest webreq = (HttpWebRequest)WebRequest.Create(StockQuoteUrl);
                    // Get the response from the Internet resource.
                    HttpWebResponse webresp = (HttpWebResponse)webreq.GetResponse();
                    // Read the body of the response from the server.

                    HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
                    string pageSource;
                    using (StreamReader sr = new StreamReader(webresp.GetResponseStream()))
                    {
                        pageSource = sr.ReadToEnd();
                    }
                    doc.LoadHtml(pageSource.ToString());
                    if (UseYahoo)
                    {
                        string Results=string.Empty;
                        //loop through each Symbol that you provided with a "," delimiter
                        foreach (string SplitSymbol in Symbols.Split(new char[] { ',' }))
                        {
                            Results+=SplitSymbol + " : " + doc.GetElementbyId("yfs_l10_" + SplitSymbol).InnerText + Environment.NewLine;
                        }
                        return (Results);
                    }
                    else
                    {
                        return (doc.GetElementbyId("ref_14135_l").InnerText);
                    }

                }
                catch (WebException Webex)
                {
                    return("SYSTEM ERROR DOWNLOADING SYMBOL: " + Webex.ToString());

                }

            }
        }

Eclipse says: “Workspace in use or cannot be created, chose a different one.” How do I unlock a workspace?

The reason this was happening to me (with Photon) was easily fixed by changing an Eclipse general preference:

Window -> Preferences -> General: Uncheck: "Always run in background"

Once you make that change, whenever you shutdown Eclipse, it will no longer leave the javaw.exe process running in the background. I’m guessing this is a bug in Photon (or a bug with using the Amazon Corretto OpenJDK version of Java with Eclipse) that will one day be fixed.

What are good message queue options for nodejs?

you could use redis with the lightning fast node_redis client. It even has built-in pubsub semantics.

Javascript - How to detect if document has loaded (IE 7/Firefox 3)

You probably want to use something like jQuery, which makes JS programming easier.

Something like:

$(document).ready(function(){
   // Your code here
});

Would seem to do what you are after.

Facebook Open Graph not clearing cache

Years later and this is still a common problem, but its not always facebook's cache: It is very often human error (allow me to elaborate)

OG:TYPE effects your image scrape:

  1. https://ogp.me/#type_article not the same as https://ogp.me/#type_website

Be aware that og:type=website will cause any /sub-pages/ of that url to become "canonical". This means you will have trouble getting your images to update using the scraper no matter what you do.

Consider this "assumption and common mistake"

-<meta property="og:type" content="website" /> => https://www.example.org (parent)
-<meta property="og:type" content="website" /> => https://www.example.org/sub-page/
-<meta property="og:type" content="website" /> => https://www.example.org/sub-page/child-2/
- Ergo: /sub-page/ and /child-2/ will inherit the og:image of the parent

Those are not "all websites", 1 is a website, the others are articles.

If you do that Facebook will think all of those are canonical and it will put the FIRST og:image into all of them. (try it, you'll see) - if you set the og:url to be your root or parent domain you've told facebook they are all canonical. (there is good reason for that, but its off topic)

Consider this solution (which is what most people "really want")

-<meta property="og:type" content="article" /> => https://www.example.org/sub-page/
-<meta property="og:type" content="article" /> => https://www.example.org/sub-page/child-2/

If you do that now Facebook will give you far far less problems with scraping your NEW images.

In closing, YES the cache busters, random vars, changing urls and suggestions here can work, but they will seem like "intermittent voodoo" if the og:type is not specified correctly.

PS: remember that a CDN or serverside cache will serve to Facebook's scraper even if you "think" you can see the most recent version. (I wont spend any time on this other than to point out it will waste colossal amounts of your time if not double checked.)

How to switch databases in psql?

Though not explicitly stated in the question, the purpose is to connect to a specific schema/database.

Another option is to directly connect to the schema. Example:

sudo -u postgres psql -d my_database_name

Source from man psql:

-d dbname
--dbname=dbname
   Specifies the name of the database to connect to. This is equivalent to specifying dbname as the first non-option argument on the command line.

   If this parameter contains an = sign or starts with a valid URI prefix (postgresql:// or postgres://), it is treated as a conninfo string. See Section 31.1.1, “Connection Strings”, in the
   documentation for more information.

Controlling number of decimal digits in print output in R

One more solution able to control the how many decimal digits to print out based on needs (if you don't want to print redundant zero(s))

For example, if you have a vector as elements and would like to get sum of it

elements <- c(-1e-05, -2e-04, -3e-03, -4e-02, -5e-01, -6e+00, -7e+01, -8e+02)
sum(elements)
## -876.5432

Apparently, the last digital as 1 been truncated, the ideal result should be -876.54321, but if set as fixed printing decimal option, e.g sprintf("%.10f", sum(elements)), redundant zero(s) generate as -876.5432100000

Following the tutorial here: printing decimal numbers, if able to identify how many decimal digits in the certain numeric number, like here in -876.54321, there are 5 decimal digits need to print, then we can set up a parameter for format function as below:

decimal_length <- 5
formatC(sum(elements), format = "f", digits = decimal_length)
## -876.54321

We can change the decimal_length based on each time query, so it can satisfy different decimal printing requirement.

How can I make a button have a rounded border in Swift?

I think the easiest and the cleanest way, is to use protocol to avoid inherit and code repetition. You can change this properties directly from storyboard

protocol Traceable {
    var cornerRadius: CGFloat { get set }
    var borderColor: UIColor? { get set }
    var borderWidth: CGFloat { get set }
}

extension UIView: Traceable {

    @IBInspectable var cornerRadius: CGFloat {
        get { return layer.cornerRadius }
        set {
            layer.masksToBounds = true
            layer.cornerRadius = newValue
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            guard let cgColor = layer.borderColor else { return nil }
            return  UIColor(cgColor: cgColor)
        }
        set { layer.borderColor = newValue?.cgColor }
    }

    @IBInspectable var borderWidth: CGFloat {
        get { return layer.borderWidth }
        set { layer.borderWidth = newValue }
    }
}

Update

In this link you can find an example with the utility of Traceable protocol

enter image description here

undefined offset PHP error

Undefined offset error in PHP is Like 'ArrayIndexOutOfBoundException' in Java.

example:

<?php
$arr=array('Hello','world');//(0=>Hello,1=>world)
echo $arr[2];
?>

error: Undefined offset 2

It means you're referring to an array key that doesn't exist. "Offset" refers to the integer key of a numeric array, and "index" refers to the string key of an associative array.

How to export DataTable to Excel

Try this function pass the datatable and file path where you want to export

public void CreateCSVFile(ref DataTable dt, string strFilePath)
{            
    try
    {
        // Create the CSV file to which grid data will be exported.
        StreamWriter sw = new StreamWriter(strFilePath, false);
        // First we will write the headers.
        //DataTable dt = m_dsProducts.Tables[0];
        int iColCount = dt.Columns.Count;
        for (int i = 0; i < iColCount; i++)
        {
            sw.Write(dt.Columns[i]);
            if (i < iColCount - 1)
            {
                sw.Write(",");
            }
        }
        sw.Write(sw.NewLine);

        // Now write all the rows.

        foreach (DataRow dr in dt.Rows)
        {
            for (int i = 0; i < iColCount; i++)
            {
                if (!Convert.IsDBNull(dr[i]))
                {
                    sw.Write(dr[i].ToString());
                }
                if (i < iColCount - 1)
                {
                    sw.Write(",");
                }
            }

            sw.Write(sw.NewLine);
        }
        sw.Close();
    }
    catch (Exception ex)
    {
        throw ex;
    }
}

JavaScript/JQuery: $(window).resize how to fire AFTER the resize is completed?

Actually, as I know, you can't do some actions exactly when resize is off, simply because you don't know future user's actions. But you can assume the time passed between two resize events, so if you wait a little more than this time and no resize is made, you can call your function.
Idea is that we use setTimeout and it's id in order to save or delete it. For example we know that time between two resize events is 500ms, therefore we will wait 750ms.

_x000D_
_x000D_
var a;_x000D_
$(window).resize(function(){_x000D_
  clearTimeout(a);_x000D_
  a = setTimeout(function(){_x000D_
    // call your function_x000D_
  },750);_x000D_
});
_x000D_
_x000D_
_x000D_

R: how to label the x-axis of a boxplot

If you read the help file for ?boxplot, you'll see there is a names= parameter.

     boxplot(apple, banana, watermelon, names=c("apple","banana","watermelon"))

enter image description here

How do I determine the dependencies of a .NET application?

To browse .NET code dependencies, you can use the capabilities of the tool NDepend. The tool proposes:

For example such query can look like:

from m in Methods 
let depth = m.DepthOfIsUsing("NHibernate.NHibernateUtil.Entity(Type)") 
where depth  >= 0 && m.IsUsing("System.IDisposable")
orderby depth
select new { m, depth }

And its result looks like: (notice the code metric depth, 1 is for direct callers, 2 for callers of direct callers...) (notice also the Export to Graph button to export the query result to a Call Graph)

NDepend dependencies browsing through C# LINQ query

The dependency graph looks like:

NDepend Dependency Graph

The dependency matrix looks like:

NDepend Dependency Matrix

The dependency matrix is de-facto less intuitive than the graph, but it is more suited to browse complex sections of code like:

NDepend Matrix vs Graph

Disclaimer: I work for NDepend

How to determine device screen size category (small, normal, large, xlarge) using code?

Thanks for the answers above, that helped me a lot :-) But for those (like me) forced to still support Android 1.5 we can use java reflection for backward compatible:

Configuration conf = getResources().getConfiguration();
int screenLayout = 1; // application default behavior
try {
    Field field = conf.getClass().getDeclaredField("screenLayout");
    screenLayout = field.getInt(conf);
} catch (Exception e) {
    // NoSuchFieldException or related stuff
}
// Configuration.SCREENLAYOUT_SIZE_MASK == 15
int screenType = screenLayout & 15;
// Configuration.SCREENLAYOUT_SIZE_SMALL == 1
// Configuration.SCREENLAYOUT_SIZE_NORMAL == 2
// Configuration.SCREENLAYOUT_SIZE_LARGE == 3
// Configuration.SCREENLAYOUT_SIZE_XLARGE == 4
if (screenType == 1) {
    ...
} else if (screenType == 2) {
    ...
} else if (screenType == 3) {
    ...
} else if (screenType == 4) {
    ...
} else { // undefined
    ...
}

How do I get PHP errors to display?

If it is on the command line, you can run php with -ddisplay_errors=1 to override the setting in php.ini:

php -ddisplay_errors=1 script.php

MySQL maximum memory usage

in /etc/my.cnf:

[mysqld]
...

performance_schema = 0

table_cache = 0
table_definition_cache = 0
max-connect-errors = 10000

query_cache_size = 0
query_cache_limit = 0

...

Good work on server with 256MB Memory.

Count the number of occurrences of a string in a VARCHAR field?

try this:

 select TITLE,
        (length(DESCRIPTION )-length(replace(DESCRIPTION ,'value','')))/5 as COUNT 
  FROM <table> 


SQL Fiddle Demo

Apache 13 permission denied in user's home directory

Can't you set the Loglevel in httpd.conf to debug? (I'm using FreeBSD)

ee usr/local/etc/apache22/httpd.conf

change loglevel :

'LogLevel: Control the number of messages logged to the error_log. Possible values include: debug, info, notice, warn, error, crit, alert, emerg.'

Try changing to debug and re-checking the error log after that.

Difference between EXISTS and IN in SQL?

If you are using the IN operator, the SQL engine will scan all records fetched from the inner query. On the other hand if we are using EXISTS, the SQL engine will stop the scanning process as soon as it found a match.

Android ADB devices unauthorized

Try this uncheck the "verify apps via USB" in developer options and then turn on and off the "USB Debugging". It works with me.

How to analyse the heap dump using jmap in java

If you use Eclipse as your IDE I would recommend the excellent eclipse plugin memory analyzer

Another option is to use JVisualVM, it can read (and create) heap dumps as well, and is shipped with every JDK. You can find it in the bin directory of your JDK.

JCheckbox - ActionListener and ItemListener?

For reference, here's an sscce that illustrates the difference. Console:

SELECTED
ACTION_PERFORMED
DESELECTED
ACTION_PERFORMED

Code:

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;

/** @see http://stackoverflow.com/q/9882845/230513 */
public class Listeners {

    private void display() {
        JFrame f = new JFrame("Listeners");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JCheckBox b = new JCheckBox("JCheckBox");
        b.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println(e.getID() == ActionEvent.ACTION_PERFORMED
                    ? "ACTION_PERFORMED" : e.getID());
            }
        });
        b.addItemListener(new ItemListener() {

            @Override
            public void itemStateChanged(ItemEvent e) {
                System.out.println(e.getStateChange() == ItemEvent.SELECTED
                    ? "SELECTED" : "DESELECTED");
            }
        });
        JPanel p = new JPanel();
        p.add(b);
        f.add(p);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Listeners().display();
            }
        });
    }
}

Can you issue pull requests from the command line on GitHub?

I'm using simple alias to create pull request,

alias pr='open -n -a "Google Chrome" --args "https://github.com/user/repo/compare/pre-master...nawarkhede:$(git_current_branch)\?expand\=1"'

AngularJS : Initialize service with asynchronous data

So I found a solution. I created an angularJS service, we'll call it MyDataRepository and I created a module for it. I then serve up this javascript file from my server-side controller:

HTML:

<script src="path/myData.js"></script>

Server-side:

@RequestMapping(value="path/myData.js", method=RequestMethod.GET)
public ResponseEntity<String> getMyDataRepositoryJS()
{
    // Populate data that I need into a Map
    Map<String, String> myData = new HashMap<String,String>();
    ...
    // Use Jackson to convert it to JSON
    ObjectMapper mapper = new ObjectMapper();
    String myDataStr = mapper.writeValueAsString(myData);

    // Then create a String that is my javascript file
    String myJS = "'use strict';" +
    "(function() {" +
    "var myDataModule = angular.module('myApp.myData', []);" +
    "myDataModule.service('MyDataRepository', function() {" +
        "var myData = "+myDataStr+";" +
        "return {" +
            "getData: function () {" +
                "return myData;" +
            "}" +
        "}" +
    "});" +
    "})();"

    // Now send it to the client:
    HttpHeaders responseHeaders = new HttpHeaders();
    responseHeaders.add("Content-Type", "text/javascript");
    return new ResponseEntity<String>(myJS , responseHeaders, HttpStatus.OK);
}

I can then inject MyDataRepository where ever I need it:

someOtherModule.service('MyOtherService', function(MyDataRepository) {
    var myData = MyDataRepository.getData();
    // Do what you have to do...
}

This worked great for me, but I am open to any feedback if anyone has any. }

Express.js Response Timeout

In case you would like to use timeout middleware and exclude a specific route:

var timeout = require('connect-timeout');
app.use(timeout('5s')); //set 5s timeout for all requests

app.use('/my_route', function(req, res, next) {
    req.clearTimeout(); // clear request timeout
    req.setTimeout(20000); //set a 20s timeout for this request
    next();
}).get('/my_route', function(req, res) {
    //do something that takes a long time
});

TypeError: tuple indices must be integers, not str

Like the error says, row is a tuple, so you can't do row["pool_number"]. You need to use the index: row[0].

How to install python-dateutil on Windows?

Looks like the setup.py uses easy_install (i.e. setuptools). Just install the setuptools package and you will be all set.

To install setuptools in Python 2.6, see the answer to this question.

How to add icons to React Native app

This is helpful for people struggling to find better site to generate icons and splashscreen

How to make padding:auto work in CSS?

You can reset the padding (and I think everything else) with initial to the default.

p {
    padding: initial;
}

In Spring MVC, how can I set the mime type header when using @ResponseBody

You may not be able to do it with @ResponseBody, but something like this should work:

package xxx;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class FooBar {
  @RequestMapping(value="foo/bar", method = RequestMethod.GET)
  public void fooBar(HttpServletResponse response) throws IOException {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    out.write(myService.getJson().getBytes());
    response.setContentType("application/json");
    response.setContentLength(out.size());
    response.getOutputStream().write(out.toByteArray());
    response.getOutputStream().flush();
  }
}

How to change fontFamily of TextView in Android

What you want is not possible. You must need to set TypeFace in your Code.

In XML what you can do is

android:typeface="sans" | "serif" | "monospace"

other then this you can not play much with the Fonts in XML. :)

For Arial you need to set type face in your code.

Elevating process privilege programmatically?

According to the article Chris Corio: Teach Your Apps To Play Nicely With Windows Vista User Account Control, MSDN Magazine, Jan. 2007, only ShellExecute checks the embedded manifest and prompts the user for elevation if needed, while CreateProcess and other APIs don't. Hope it helps.

See also: same article as .chm.

css3 transition animation on load?

Very little Javascript is necessary:

window.onload = function() {
    document.body.className += " loaded";
}

Now the CSS:

.fadein {
    opacity: 0;
    -moz-transition: opacity 1.5s;
    -webkit-transition: opacity 1.5s;
    -o-transition: opacity 1.5s;
    transition: opacity 1.5s;
}

body.loaded .fadein {
    opacity: 1;
}

I know the question said "without Javascript", but I think it's worth pointing out that there is an easy solution involving one line of Javascript.

It could even be inline Javascript, something like that:

<body onload="document.body.className += ' loaded';" class="fadein">

That's all the JavaScript that's needed.

Change default text in input type="file"?

My solution...

HTML :

<input type="file" id="uploadImages" style="display:none;" multiple>

<input type="button" id="callUploadImages" value="Select">
<input type="button" id="uploadImagesInfo" value="0 file(s)." disabled>
<input type="button" id="uploadProductImages" value="Upload">

Jquery:

$('#callUploadImages').click(function(){

    $('#uploadImages').click();
});

$('#uploadImages').change(function(){

    var uploadImages = $(this);
    $('#uploadImagesInfo').val(uploadImages[0].files.length+" file(s).");
});

This is just evil :D

Is a LINQ statement faster than a 'foreach' loop?

Why should LINQ be faster? It also uses loops internally.

Most of the times, LINQ will be a bit slower because it introduces overhead. Do not use LINQ if you care much about performance. Use LINQ because you want shorter better readable and maintainable code.

How to change an element's title attribute using jQuery

I beleive

$("#myElement").attr("title", "new title value")

or

$("#myElement").prop("title", "new title value")

should do the trick...

I think you can find all the core functions in the jQuery Docs, although I hate the formatting.

Add space between cells (td) using css

Mine is:

border-spacing: 10px;
border-collapse: separate;

What is the difference between ExecuteScalar, ExecuteReader and ExecuteNonQuery?

ExecuteNonQuery

This ExecuteNonQuery method will be used only for insert, update and delete, Create, and SET statements. ExecuteNonQuery method will return number of rows effected with INSERT, DELETE or UPDATE operations.

ExecuteScalar

It’s very fast to retrieve single values from database. Execute Scalar will return single row single column value i.e. single value, on execution of SQL Query or Stored procedure using command object. ExecuteReader

Execute Reader will be used to return the set of rows, on execution of SQL Query or Stored procedure using command object. This one is forward only retrieval of records and it is used to read the table values from first to last.

For loop in Oracle SQL

You will certainly be able to do that using WITH clause, or use analytic functions available in Oracle SQL.

With some effort you'd be able to get anything out of them in terms of cycles as in ordinary procedural languages. Both approaches are pretty powerful compared to ordinary SQL.

http://www.dba-oracle.com/t_with_clause.htm

http://www.orafaq.com/node/55

It requires some effort though. Don't be afraid to post a concrete example.

Using simple pseudo table DUAL helps too.

Ignore files that have already been committed to a Git repository

Yes - .gitignore system only ignores files not currently under version control from git.

I.e. if you've already added a file called test.txt using git-add, then adding test.txt to .gitignore will still cause changes to test.txt to be tracked.

You would have to git rm test.txt first and commit that change. Only then will changes to test.txt be ignored.

How to fix an UnsatisfiedLinkError (Can't find dependent libraries) in a JNI project

I was facing same issue with ffmpeg library after merging two Android projects as one project.

Actually issue was arriving due to two different versions of ffmpeg library but they were loaded with same names in memory. One library was placed in JNiLibs while other was inside another library used as module. I was not able to modify the code of module as it was readonly so I renamed the one used in my own code to ffmpegCamera and loaded it in memory with same name.

System.loadLibrary("ffmpegCamera");

This resolved the issue and now both versions of libraries are loading well as separate name and process id in memory.

Correct way to create rounded corners in Twitter Bootstrap

With bootstrap4 you can easily do it like this :-

class="rounded" 

or

class="rounded-circle"

Angular ng-repeat add bootstrap row every 3 or 4 cols

Okay, this solution is far simpler than the ones already here, and allows different column widths for different device widths.

<div class="row">
    <div ng-repeat="image in images">
        <div class="col-xs-6 col-sm-4 col-md-3 col-lg-2">
            ... your content here ...
        </div>
        <div class="clearfix visible-lg" ng-if="($index + 1) % 6 == 0"></div>
        <div class="clearfix visible-md" ng-if="($index + 1) % 4 == 0"></div>
        <div class="clearfix visible-sm" ng-if="($index + 1) % 3 == 0"></div>
        <div class="clearfix visible-xs" ng-if="($index + 1) % 2 == 0"></div>
    </div>
</div>

Note that the % 6 part is supposed to equal the number of resulting columns. So if on the column element you have the class col-lg-2 there will be 6 columns, so use ... % 6.

This technique (excluding the ng-if) is actually documented here: Bootstrap docs