Programs & Examples On #Clique problem

In computer science, the clique problem refers to any of the problems related to finding particular complete subgraphs ("cliques") in a graph, i.e., sets of elements where each pair of elements is connected.

Spring configure @ResponseBody JSON format

You can configure the ObjectMapper as a bean in your Spring xml file. What holds a reference to the ObjectMapper is the MappingJacksonJsonView class. You then need to attach the view to a ViewResolver.

Something like this should work:

<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
      <property name="mediaTypes">
      <map>
        <entry key="json" value="application/json" />
        <entry key="html" value="text/html" />
      </map>
    </property>
    <property name="viewResolvers">
      <list>
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
          <property name="prefix" value="/WEB-INF/jsp/" />
          <property name="suffix" value=".jsp" />
        </bean>
      </list>
    </property>
    <property name="defaultViews">
      <list>
        <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">
          <property name="prefixJson" value="false" />
          <property name="objectMapper" value="customObjectMapper" />
        </bean>
      </list>
    </property>
  </bean>

Where customObjectMapper is defined elsewhere in the xml file. Note that you can directly set Spring property values with the Enums Jackson defines; see this question.

Also, ContentNegotiatingViewResolver probably isn't required, it's just the code I am using in an existing project.

Handling multiple IDs in jQuery

Solution:

To your secondary question

var elem1 = $('#elem1'),
    elem2 = $('#elem2'),
    elem3 = $('#elem3');

You can use the variable as the replacement of selector.

elem1.css({'display':'none'}); //will work

In the below case selector is already stored in a variable.

$(elem1,elem2,elem3).css({'display':'none'}); // will not work

How to run Gradle from the command line on Mac bash

./gradlew

Your directory with gradlew is not included in the PATH, so you must specify path to the gradlew. . means "current directory".

How to setup Main class in manifest file in jar produced by NetBeans project

I read and read and read to figure out why I was getting a class not found error, it turns out the manifest.mf had an error in the line:

Main-Class: com.example.MainClass

I fixed the error by going to Project Properties dialog (right-click Project Files), then Run and Main Class and corrected whatever Netbeans decided to put here. Netbean inserted the project name instead of the class name. No idea why. Probably inebriated on muratina...

How can I convert ArrayList<Object> to ArrayList<String>?

Using Java 8 you can do:

List<Object> list = ...;
List<String> strList = list.stream()
                           .map( Object::toString )
                           .collect( Collectors.toList() );

How can I check if given int exists in array?

int index = std::distance(std::begin(myArray), std::find(begin(myArray), end(std::myArray), VALUE));

Returns an invalid index (length of the array) if not found.

How should I set the default proxy to use default credentials?

From .NET 2.0 you shouldn't need to do this. If you do not explicitly set the Proxy property on a web request it uses the value of the static WebRequest.DefaultWebProxy. If you wanted to change the proxy being used by all subsequent WebRequests, you can set this static DefaultWebProxy property.

The default behaviour of WebRequest.DefaultWebProxy is to use the same underlying settings as used by Internet Explorer.

If you wanted to use different proxy settings to the current user then you would need to code

WebRequest webRequest = WebRequest.Create("http://stackoverflow.com/");
webRequest.Proxy = new WebProxy("http://proxyserver:80/",true);

or

WebRequest.DefaultWebProxy = new WebProxy("http://proxyserver:80/",true);

You should also remember the object model for proxies includes the concept that the proxy can be different depending on the destination hostname. This can make things a bit confusing when debugging and checking the property of webRequest.Proxy. Call

webRequest.Proxy.GetProxy(new Uri("http://google.com.au")) to see the actual details of the proxy server that would be used.

There seems to be some debate about whether you can set webRequest.Proxy or WebRequest.DefaultWebProxy = null to prevent the use of any proxy. This seems to work OK for me but you could set it to new DefaultProxy() with no parameters to get the required behaviour. Another thing to check is that if a proxy element exists in your applications config file, the .NET Framework will NOT use the proxy settings in Internet Explorer.

The MSDN Magazine article Take the Burden Off Users with Automatic Configuration in .NET gives further details of what is happening under the hood.

Check number of arguments passed to a Bash script

It might be a good idea to use arithmetic expressions if you're dealing with numbers.

if (( $# != 1 )); then
    >&2 echo "Illegal number of parameters"
fi

>&2 is used to write the error message to stderr.

Printing column separated by comma using Awk command line

A simple, although -less solution in :

while IFS=, read -r a a a b; do echo "$a"; done <inputfile

It works faster for small files (<100 lines) then as it uses less resources (avoids calling the expensive fork and execve system calls).

EDIT from Ed Morton (sorry for hi-jacking the answer, I don't know if there's a better way to address this):

To put to rest the myth that shell will run faster than awk for small files:

$ wc -l file
99 file

$ time while IFS=, read -r a a a b; do echo "$a"; done <file >/dev/null

real    0m0.016s
user    0m0.000s
sys     0m0.015s

$ time awk -F, '{print $3}' file >/dev/null

real    0m0.016s
user    0m0.000s
sys     0m0.015s

I expect if you get a REALY small enough file then you will see the shell script run in a fraction of a blink of an eye faster than the awk script but who cares?

And if you don't believe that it's harder to write robust shell scripts than awk scripts, look at this bug in the shell script you posted:

$ cat file
a,b,-e,d
$ cut -d, -f3 file
-e
$ awk -F, '{print $3}' file
-e
$ while IFS=, read -r a a a b; do echo "$a"; done <file

$

How do I convert a factor into date format?

You were close. format= needs to be added to the as.Date call:

mydate <- factor("1/15/2006 0:00:00")
as.Date(mydate, format = "%m/%d/%Y")
## [1] "2006-01-15"

'Property does not exist on type 'never'

if you're receiving the error in parameter, so keep any or any[] type of input like below

getOptionLabel={(option: any) => option!.name}
 <Autocomplete
    options={tests}
    getOptionLabel={(option: any) => option!.name}
    ....
  />

How to check if a row exists in MySQL? (i.e. check if an email exists in MySQL)

After validation and before INSERT check if username already exists, using mysqli(procedural). This works:

//check if username already exists
       include 'phpscript/connect.php'; //connect to your database

       $sql = "SELECT username FROM users WHERE username = '$username'";
       $result = $conn->query($sql);

       if($result->num_rows > 0) {
           $usernameErr =  "username already taken"; //takes'em back to form
       } else { // go on to INSERT new record

How can I reference a dll in the GAC from Visual Studio?

In VS, right click your project, select "Add Reference...", and you will see all the namespaces that exist in your GAC. Choose Microsoft.SqlServer.Management.RegisteredServers and click OK, and you should be good to go

EDIT:

That is the way you want to do this most of the time. However, after a bit of poking around I found this issue on MS Connect. MS says it is a known deployment issue, and they don't have a work around. The guy says if he copies the dll from the GAC folder and drops it in his bin, it works.

Setting up an MS-Access DB for multi-user access

Access is a great multi-user database. It has lots of built in features to handle the multi-user situation. In fact, it is so very popular because it is such a great multi-user database. There is an upper limit on how many users can all use the database at the same time doing updates and edits - depending on how knowledgeable the developer is about access and how the database has been designed - anywhere from 20 users to approx 50 users. Some access databases can be built to handle up to 50 concurrent users, while many others can handle 20 or 25 concurrent users updating the database. These figures have been observed for databases that have been in use for several or more years and have been discussed many times on the access newsgroups.

How can I create a dropdown menu from a List in Tkinter?

To create a "drop down menu" you can use OptionMenu in tkinter

Example of a basic OptionMenu:

from Tkinter import *

master = Tk()

variable = StringVar(master)
variable.set("one") # default value

w = OptionMenu(master, variable, "one", "two", "three")
w.pack()

mainloop()

More information (including the script above) can be found here.


Creating an OptionMenu of the months from a list would be as simple as:

from tkinter import *

OPTIONS = [
"Jan",
"Feb",
"Mar"
] #etc

master = Tk()

variable = StringVar(master)
variable.set(OPTIONS[0]) # default value

w = OptionMenu(master, variable, *OPTIONS)
w.pack()

mainloop()

In order to retrieve the value the user has selected you can simply use a .get() on the variable that we assigned to the widget, in the below case this is variable:

from tkinter import *

OPTIONS = [
"Jan",
"Feb",
"Mar"
] #etc

master = Tk()

variable = StringVar(master)
variable.set(OPTIONS[0]) # default value

w = OptionMenu(master, variable, *OPTIONS)
w.pack()

def ok():
    print ("value is:" + variable.get())

button = Button(master, text="OK", command=ok)
button.pack()

mainloop()

I would highly recommend reading through this site for further basic tkinter information as the above examples are modified from that site.

Pass variables to Ruby script via command line

tl;dr

I know this is old, but getoptlong wasn't mentioned here and it's probably the best way to parse command line arguments today.


Parsing command line arguments

I strongly recommend getoptlong. It's pretty easy to use and works like a charm. Here is an example extracted from the link above

require 'getoptlong'

opts = GetoptLong.new(
    [ '--help', '-h', GetoptLong::NO_ARGUMENT ],
    [ '--repeat', '-n', GetoptLong::REQUIRED_ARGUMENT ],
    [ '--name', GetoptLong::OPTIONAL_ARGUMENT ]
)

dir = nil
name = nil
repetitions = 1
opts.each do |opt, arg|
    case opt
        when '--help'
            puts <<-EOF
hello [OPTION] ... DIR

-h, --help:
     show help

--repeat x, -n x:
     repeat x times

--name [name]:
     greet user by name, if name not supplied default is John

DIR: The directory in which to issue the greeting.
            EOF
        when '--repeat'
            repetitions = arg.to_i
        when '--name'
            if arg == ''
                name = 'John'
            else
                name = arg
            end
    end
end

if ARGV.length != 1
    puts "Missing dir argument (try --help)"
    exit 0
end

dir = ARGV.shift

Dir.chdir(dir)
for i in (1..repetitions)
    print "Hello"
    if name
        print ", #{name}"
    end
    puts
end

You can call it like this ruby hello.rb -n 6 --name -- /tmp

What OP is trying to do

In this case I think the best option is to use YAML files as suggested in this answer

How to change the integrated terminal in visual studio code or VSCode

I was successful via settings > Terminal > Integrated > Shell: Linux

from there I edited the path of the shell to be /bin/zsh from the default /bin/bash

  • there are also options for OSX and Windows as well

screencap of vs settings view

@charlieParker - here's what i'm seeing for available commands in the command pallette

enter image description here

What's Mongoose error Cast to ObjectId failed for value XXX at path "_id"?

You can also use ObjectId.isValid like the following :

if (!ObjectId.isValid(userId)) return Error({ status: 422 })

Eclipse Generate Javadoc Wizard: what is "Javadoc Command"?

You may need to add a JDK (Java Development Kit) to the installed JRE's within Eclipse

Go to Window->Preferences->Java->Installed JRE's

In the Name column if you do not have a JDK as your default, then you will need to add it.

Click the "Add" Button and locate the JDK on your machine. You may find it in this location: C:\Program Files\Java\jdk1.x.y
Where x and y are numbers.

If there are no JDK's installed on your machine then download and install the Java SE (Standard Edition) from the Oracle website.

Then do the steps above again. Be sure that it is set as the default JRE to use.

Then go back to the Projects->Generate Javadoc... dialog

Now it should work.

Good Luck.

How to run DOS/CMD/Command Prompt commands from VB.NET?

You Can try This To Run Command Then cmd Exits

Process.Start("cmd", "/c YourCode")

You Can try This To Run The Command And Let cmd Wait For More Commands

Process.Start("cmd", "/k YourCode")

JSLint is suddenly reporting: Use the function form of "use strict"

Add a file .jslintrc (or .jshintrc in the case of jshint) at the root of your project with the following content:

{
    "node": true
}

How can I erase all inline styles with javascript and leave only the styles specified in the css style sheet?

If you need to just empty the style of an element then:
element.style.cssText = null;
This should do good. Hope it helps!

How to center buttons in Twitter Bootstrap 3?

According to the Twitter Bootstrap documentation: http://getbootstrap.com/css/#helper-classes-center

<!-- Button -->
<div class="form-group">
   <label class="col-md-4 control-label" for="singlebutton"></label>
   <div class="col-md-4 center-block">
      <button id="singlebutton" name="singlebutton" class="btn btn-primary center-block">
          Next Step!
       </button>
   </div>  
</div>

All the class center-block does is to tell the element to have a margin of 0 auto, the auto being the left/right margins. However, unless the class text-center or css text-align:center; is set on the parent, the element does not know the point to work out this auto calculation from so will not center itself as anticipated.

See an example of the code above here: https://jsfiddle.net/Seany84/2j9pxt1z/

SQL LIKE condition to check for integer?

If you want to search as string, you can cast to text like this:

SELECT * FROM books WHERE price::TEXT LIKE '123%'

How to compare character ignoring case in primitive types

You can change the case of String before using it, like this

String name1 = fname.getText().toString().toLowerCase(); 
String name2 = sname.getText().toString().toLowerCase();

Then continue with rest operation.

Fastest method to escape HTML tags as HTML entities?

The AngularJS source code also has a version inside of angular-sanitize.js.

var SURROGATE_PAIR_REGEXP = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g,
    // Match everything outside of normal chars and " (quote character)
    NON_ALPHANUMERIC_REGEXP = /([^\#-~| |!])/g;
/**
 * Escapes all potentially dangerous characters, so that the
 * resulting string can be safely inserted into attribute or
 * element text.
 * @param value
 * @returns {string} escaped text
 */
function encodeEntities(value) {
  return value.
    replace(/&/g, '&amp;').
    replace(SURROGATE_PAIR_REGEXP, function(value) {
      var hi = value.charCodeAt(0);
      var low = value.charCodeAt(1);
      return '&#' + (((hi - 0xD800) * 0x400) + (low - 0xDC00) + 0x10000) + ';';
    }).
    replace(NON_ALPHANUMERIC_REGEXP, function(value) {
      return '&#' + value.charCodeAt(0) + ';';
    }).
    replace(/</g, '&lt;').
    replace(/>/g, '&gt;');
}

Get current time in milliseconds in Python?

def TimestampMillisec64():
    return int((datetime.datetime.utcnow() - datetime.datetime(1970, 1, 1)).total_seconds() * 1000) 

How do I get just the date when using MSSQL GetDate()?

Slight bias to SQL Server

Summary

DATEADD(day, DATEDIFF(day, 0, GETDATE()), 0)

SQL Server 2008 has date type though. So just use

CAST(GETDATE() AS DATE)

Edit: To add one day, compare to the day before "zero"

DATEADD(day, DATEDIFF(day, -1, GETDATE()), 0)

From cyberkiwi:

An alternative that does not involve 2 functions is (the +1 can be in or ourside the brackets).

DATEDIFF(DAY, 0, GETDATE() +1)

DateDiff returns a number but for all purposes this will work as a date wherever you intend to use this expression, except converting it to VARCHAR directly - in which case you would have used the CONVERT approach directly on GETDATE(), e.g.

convert(varchar, GETDATE() +1, 102)

Android : difference between invisible and gone?

  • View.INVISIBLE->The View is invisible but it will occupy some space in layout

  • View.GONE->The View is not visible and it will not occupy any space in layout

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

Building on what is mentioned in the comments, the simplest solution would be:

@RequestMapping(method = RequestMethod.PUT, consumes = MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public Collection<BudgetDTO> updateConsumerBudget(@RequestBody SomeDto someDto) throws GeneralException, ParseException {

    //whatever

}

class SomeDto {

   private List<WhateverBudgerPerDateDTO> budgetPerDate;


  //getters setters
}

The solution assumes that the HTTP request you are creating actually has

Content-Type:application/json instead of text/plain

apply drop shadow to border-top only?

Something like this?

_x000D_
_x000D_
div {_x000D_
  border: 1px solid #202020;_x000D_
  margin-top: 25px;_x000D_
  margin-left: 25px;_x000D_
  width: 158px;_x000D_
  height: 158px;_x000D_
  padding-top: 25px;_x000D_
  -webkit-box-shadow: 0px -4px 3px rgba(50, 50, 50, 0.75);_x000D_
  -moz-box-shadow: 0px -4px 3px rgba(50, 50, 50, 0.75);_x000D_
  box-shadow: 0px -4px 3px rgba(50, 50, 50, 0.75);_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

how to place last div into right top corner of parent div? (css)

_x000D_
_x000D_
.block1 {_x000D_
    color: red;_x000D_
    width: 100px;_x000D_
    border: 1px solid green;_x000D_
    position: relative;_x000D_
}_x000D_
_x000D_
.block2 {_x000D_
    color: blue;_x000D_
    width: 70px;_x000D_
    border: 2px solid black;_x000D_
    position: absolute;_x000D_
    top: 0px;_x000D_
    right: 0px;_x000D_
}
_x000D_
<div class='block1'>_x000D_
  <p>text</p>_x000D_
  <p>text2</p>_x000D_
  <div class='block2'>block2</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Should do it. Assuming you don't need it to flow.

Auto-loading lib files in Rails 4

This might help someone like me that finds this answer when searching for solutions to how Rails handles the class loading ... I found that I had to define a module whose name matched my filename appropriately, rather than just defining a class:

In file lib/development_mail_interceptor.rb (Yes, I'm using code from a Railscast :))

module DevelopmentMailInterceptor
  class DevelopmentMailInterceptor
    def self.delivering_email(message)
      message.subject = "intercepted for: #{message.to} #{message.subject}"
      message.to = "[email protected]"
    end
  end
end

works, but it doesn't load if I hadn't put the class inside a module.

String.Format like functionality in T-SQL?

If you are using SQL Server 2012 and above, you can use FORMATMESSAGE. eg.

DECLARE @s NVARCHAR(50) = 'World';
DECLARE @d INT = 123;
SELECT FORMATMESSAGE('Hello %s, %d', @s, @d)
-- RETURNS 'Hello World, 123'

More examples from MSDN: FORMATMESSAGE

SELECT FORMATMESSAGE('Signed int %i, %d %i, %d, %+i, %+d, %+i, %+d', 5, -5, 50, -50, -11, -11, 11, 11);
SELECT FORMATMESSAGE('Signed int with leading zero %020i', 5);
SELECT FORMATMESSAGE('Signed int with leading zero 0 %020i', -55);
SELECT FORMATMESSAGE('Unsigned int %u, %u', 50, -50);
SELECT FORMATMESSAGE('Unsigned octal %o, %o', 50, -50);
SELECT FORMATMESSAGE('Unsigned hexadecimal %x, %X, %X, %X, %x', 11, 11, -11, 50, -50);
SELECT FORMATMESSAGE('Unsigned octal with prefix: %#o, %#o', 50, -50);
SELECT FORMATMESSAGE('Unsigned hexadecimal with prefix: %#x, %#X, %#X, %X, %x', 11, 11, -11, 50, -50);
SELECT FORMATMESSAGE('Hello %s!', 'TEST');
SELECT FORMATMESSAGE('Hello %20s!', 'TEST');
SELECT FORMATMESSAGE('Hello %-20s!', 'TEST');
SELECT FORMATMESSAGE('Hello %20s!', 'TEST');

NOTES:

  • Undocumented in 2012
  • Limited to 2044 characters
  • To escape the % sign, you need to double it.
  • If you are logging errors in extended events, calling FORMATMESSAGE comes up as a (harmless) error

Guid is all 0's (zeros)?

Use the static method Guid.NewGuid() instead of calling the default constructor.

var responseObject = proxy.CallService(new RequestObject
{
    Data = "misc. data",
    Guid = Guid.NewGuid()
});

List append() in for loop

You don't need the assignment, list.append(x) will always append x to a and therefore there's no need te redefine a.

a = []
for i in range(5):    
    a.append(i)
print(a)

is all you need. This works because lists are mutable.

Also see the docs on data structures.

Get/pick an image from Android's built-in Gallery app programmatically

basis with the above code, I reflected the code like below, may be it's more suitable:

public String getPath(Uri uri) {
    String selectedImagePath;
    //1:MEDIA GALLERY --- query from MediaStore.Images.Media.DATA
    String[] projection = { MediaStore.Images.Media.DATA };
    Cursor cursor = managedQuery(uri, projection, null, null, null);
    if(cursor != null){
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        selectedImagePath = cursor.getString(column_index);
    }else{
        selectedImagePath = null;
    }

    if(selectedImagePath == null){
        //2:OI FILE Manager --- call method: uri.getPath()
        selectedImagePath = uri.getPath();
    }
    return selectedImagePath;
}

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

There are many other binaries that need to be linked so I think it's much better to try something like sudo update-alternatives --all and choosing the right alternatives for everything else besides java and javac.

Preserve Line Breaks From TextArea When Writing To MySQL

why make is sooooo hard people when it can be soooo easy :)

//here is the pull from the form
$your_form_text = $_POST['your_form_text'];


//line 1 fixes the line breaks - line 2 the slashes
$your_form_text = nl2br($your_form_text);
$your_form_text = stripslashes($your_form_text);

//email away
$message = "Comments: $your_form_text";
mail("[email protected]", "Website Form Submission", $message, $headers);

you will obviously need headers and likely have more fields, but this is your textarea take care of

Using DateTime in a SqlParameter for Stored Procedure, format error

Here is how I add parameters:

sprocCommand.Parameters.Add(New SqlParameter("@Date_Of_Birth",Data.SqlDbType.DateTime))
sprocCommand.Parameters("@Date_Of_Birth").Value = DOB

I am assuming when you write out DOB there are no quotes.

Are you using a third-party control to get the date? I have had problems with the way the text value is generated from some of them.

Lastly, does it work if you type in the .Value attribute of the parameter without referencing DOB?

CSS: Position text in the middle of the page

Try this CSS:

h1 {
    left: 0;
    line-height: 200px;
    margin-top: -100px;
    position: absolute;
    text-align: center;
    top: 50%;
    width: 100%;
}

jsFiddle: http://jsfiddle.net/wprw3/

Reading from file using read() function

fgets would work for you. here is very good documentation on this :-
http://www.cplusplus.com/reference/cstdio/fgets/

If you don't want to use fgets, following method will work for you :-

int readline(FILE *f, char *buffer, size_t len)
{
   char c; 
   int i;

   memset(buffer, 0, len);

   for (i = 0; i < len; i++)
   {   
      int c = fgetc(f); 

      if (!feof(f)) 
      {   
         if (c == '\r')
            buffer[i] = 0;
         else if (c == '\n')
         {   
            buffer[i] = 0;

            return i+1;
         }   
         else
            buffer[i] = c; 
      }   
      else
      {   
         //fprintf(stderr, "read_line(): recv returned %d\n", c);
         return -1; 
      }   
   }   

   return -1; 
}

How to close a Java Swing application from the code

Your JFrame default close action can be set to "DISPOSE_ON_CLOSE" instead of EXIT_ON_CLOSE (why people keep using EXIT_ON_CLOSE is beyond me).

If you have any undisposed windows or non-daemon threads, your application will not terminate. This should be considered a error (and solving it with System.exit is a very bad idea).

The most common culprits are java.util.Timer and a custom Thread you've created. Both should be set to daemon or must be explicitly killed.

If you want to check for all active frames, you can use Frame.getFrames(). If all Windows/Frames are disposed of, then use a debugger to check for any non-daemon threads that are still running.

Creating a JSON array in C#

You're close. This should do the trick:

new {items = new [] {
    new {name = "command" , index = "X", optional = "0"}, 
    new {name = "command" , index = "X", optional = "0"}
}}

If your source was an enumerable of some sort, you might want to do this:

new {items = source.Select(item => new 
{
    name = item.Name, index = item.Index, options = item.Optional
})};

Fitting a Normal distribution to 1D data

Here you are not fitting a normal distribution. Replacing sns.distplot(data) by sns.distplot(data, fit=norm, kde=False) should do the trick.

How to execute a bash command stored as a string with quotes and asterisk

To eliminate the need for the cmd variable, you can do this:

eval 'mysql AMORE -u root --password="password" -h localhost -e "select host from amoreconfig"'

What are the differences and similarities between ffmpeg, libav, and avconv?

Confusing messages

These messages are rather misleading and understandably a source of confusion. Older Ubuntu versions used Libav which is a fork of the FFmpeg project. FFmpeg returned in Ubuntu 15.04 "Vivid Vervet".

The fork was basically a non-amicable result of conflicting personalities and development styles within the FFmpeg community. It is worth noting that the maintainer for Debian/Ubuntu switched from FFmpeg to Libav on his own accord due to being involved with the Libav fork.

The real ffmpeg vs the fake one

For a while both Libav and FFmpeg separately developed their own version of ffmpeg.

Libav then renamed their bizarro ffmpeg to avconv to distance themselves from the FFmpeg project. During the transition period the "not developed anymore" message was displayed to tell users to start using avconv instead of their counterfeit version of ffmpeg. This confused users into thinking that FFmpeg (the project) is dead, which is not true. A bad choice of words, but I can't imagine Libav not expecting such a response by general users.

This message was removed upstream when the fake "ffmpeg" was finally removed from the Libav source, but, depending on your version, it can still show up in Ubuntu because the Libav source Ubuntu uses is from the ffmpeg-to-avconv transition period.

In June 2012, the message was re-worded for the package libav - 4:0.8.3-0ubuntu0.12.04.1. Unfortunately the new "deprecated" message has caused additional user confusion.

Starting with Ubuntu 15.04 "Vivid Vervet", FFmpeg's ffmpeg is back in the repositories again.

libav vs Libav

To further complicate matters, Libav chose a name that was historically used by FFmpeg to refer to its libraries (libavcodec, libavformat, etc). For example the libav-user mailing list, for questions and discussions about using the FFmpeg libraries, is unrelated to the Libav project.

How to tell the difference

If you are using avconv then you are using Libav. If you are using ffmpeg you could be using FFmpeg or Libav. Refer to the first line in the console output to tell the difference: the copyright notice will either mention FFmpeg or Libav.

Secondly, the version numbering schemes differ. Each of the FFmpeg or Libav libraries contains a version.h header which shows a version number. FFmpeg will end in three digits, such as 57.67.100, and Libav will end in one digit such as 57.67.0. You can also view the library version numbers by running ffmpeg or avconv and viewing the console output.

If you want to use the real ffmpeg

Ubuntu 15.04 "Vivid Vervet" or newer

The real ffmpeg is in the repository, so you can install it with:

apt-get install ffmpeg

For older Ubuntu versions

Your options are:

These methods are non-intrusive, reversible, and will not interfere with the system or any repository packages.

Another possible option is to upgrade to Ubuntu 15.04 "Vivid Vervet" or newer and just use ffmpeg from the repository.

Also see

For an interesting blog article on the situation, as well as a discussion about the main technical differences between the projects, see The FFmpeg/Libav situation.

Filtering a data frame by values in a column

Try this:

subset(studentdata, Drink=='water')

that should do it.

How to display an error message in an ASP.NET Web Application

Roughly you can do it like that :

try
{
    //do something
}
catch (Exception ex)
{
    string script = "<script>alert('" + ex.Message + "');</script>";
    if (!Page.IsStartupScriptRegistered("myErrorScript"))
    {
         Page.ClientScript.RegisterStartupScript("myErrorScript", script);
    }
}

But I recommend you to define your custom Exception and throw it anywhere you need. At your page catch this custom exception and register your message box script.

How do I enable the column selection mode in Eclipse?

On Windows and Linux, it's AltShiftA, as RichieHindle pointed out. On OSX it's OptionCommandA (??A). It's also worth noting that the two modes can have different font preferences, so if you've changed the default text font, it can be jarring to toggle block selection modes and see the font change.

Finally, the "search commands" (Ctrl3 or Command3) pop-up will find it for you if you type block. This is useful if you use the feature just frequently enough to forget the hotkey.

notifyDataSetChanged example

I know this is a late response but I was facing a similar issue and I managed to solve it by using notifyDataSetChanged() in the right place.

So my situation was as follows.

I had to update a listview in an action bar tab (fragment) with contents returned from a completely different activity. Initially however, the listview would not reflect any changes. However, when I clicked another tab and then returned to the desired tab,the listview would be updated with the correct content from the other activity. So to solve this I used notifyDataSetChanged() of the action bar adapter in the code of the activity which had to return the data.

This is the code snippet which I used in the activity.

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    switch (item.getItemId()) 
    {
        case R.id.action_new_forward:

            FragmentTab2.mListAdapter.notifyDataSetChanged();//this updates the adapter in my action bar tab
            Intent ina = new Intent(getApplicationContext(), MainActivity.class);
            ina.putExtra("stra", values1);
            startActivity(ina);// This is the code to start the parent activity of my action bar tab(fragment).
    }
}

This activity would return some data to FragmentTab2 and it would directly update my listview in FragmentTab2.

Hope someone finds this useful!

jQuery: How can I show an image popup onclick of the thumbnail?

This is the most popular (9500 stars) and light weight (20KB minify, 7.5KB minify+gzip) popup gallery I think: Magnific-Popup

How to display multiple notifications in android

The problem is with your notificationId. Think it as an array index. Each time you update your notification, the notificationId is the place it takes to store value. As you are not incrementing your int value (in this case, your notificationId), this always replaces the previous one. The best solution I guess is to increment it just after you update a notification. And if you want to keep it persistent, then you can store the value of your notificationId in sharedPreferences. Whenever you come back, you can just grab the last integer value (notificationId stored in sharedPreferences) and use it.

How to compile a c++ program in Linux?

Try this:

g++ -o hi hi.cpp

gcc is only for C

Git - remote: Repository not found

For Mac

Open KeyChain Access and find your pssword account on password category ( you can search it on top right keychain access page)

when you find it , delete all keys related to your git source control. and try it again

enter image description here

Reading data from DataGridView in C#

 private void HighLightGridRows()
 {            
     Debugger.Launch();
     for (int i = 0; i < dtgvAppSettings.Rows.Count; i++)
     {
         String key = dtgvAppSettings.Rows[i].Cells["Key"].Value.ToString();
         if (key.ToLower().Contains("applicationpath") == true)
         {
             dtgvAppSettings.Rows[i].DefaultCellStyle.BackColor = Color.Yellow;
         }
     }
 }

matplotlib.pyplot will not forget previous plots - how can I flush/refresh?

I discovered that this behaviour only occurs after running a particular script, similar to the one in the question. I have no idea why it occurs.

It works (refreshes the graphs) if I put

plt.clf()
plt.cla()
plt.close()

after every plt.show()

The simplest way to resize an UIImage?

Proper Swift 3.0 for iOS 10+ solution: Using ImageRenderer and closure syntax:

func imageWith(newSize: CGSize) -> UIImage {
    let renderer = UIGraphicsImageRenderer(size: newSize)
    let image = renderer.image { _ in
        self.draw(in: CGRect.init(origin: CGPoint.zero, size: newSize))
    }

    return image.withRenderingMode(self.renderingMode)
}

And here's the Objective-C version:

@implementation UIImage (ResizeCategory)
- (UIImage *)imageWithSize:(CGSize)newSize
{
    UIGraphicsImageRenderer *renderer = [[UIGraphicsImageRenderer alloc] initWithSize:newSize];
    UIImage *image = [renderer imageWithActions:^(UIGraphicsImageRendererContext*_Nonnull myContext) {
        [self drawInRect:(CGRect) {.origin = CGPointZero, .size = newSize}];
    }];
    return [image imageWithRenderingMode:self.renderingMode];
}
@end

How to find SQL Server running port?

SQL Server 2000 Programs | MS SQL Server | Client Network Utility | Select TCP_IP then Properties

SQL Server 2005 Programs | SQL Server | SQL Server Configuration Manager | Select Protocols for MSSQLSERVER or select Client Protocols and right click on TCP/IP

How to delete Project from Google Developers Console

For me only way to delete project was switch language to English (UK) - from Polish and then button "DELETE" worked. If anyone have problem with not working or missing options in Google Cloud Platform I suggest switching to english after that everything works like charm...

JSONP call showing "Uncaught SyntaxError: Unexpected token : "

I run this

var data = '{"rut" : "' + $('#cb_rut').val() + '" , "email" : "' + $('#email').val() + '" }';
var data = JSON.parse(data);

$.ajax({
    type: 'GET',
    url: 'linkserverApi',
    success: function(success) {
        console.log('Success!');
        console.log(success);
    },
    error: function() {
        console.log('Uh Oh!');
    },
    jsonp: 'jsonp'

});

And edit header in the response

'Access-Control-Allow-Methods' , 'GET, POST, PUT, DELETE'

'Access-Control-Max-Age' , '3628800'

'Access-Control-Allow-Origin', 'websiteresponseUrl'

'Content-Type', 'text/javascript; charset=utf8'

How do I split a multi-line string into multiple lines?

Like the others said:

inputString.split('\n')  # --> ['Line 1', 'Line 2', 'Line 3']

This is identical to the above, but the string module's functions are deprecated and should be avoided:

import string
string.split(inputString, '\n')  # --> ['Line 1', 'Line 2', 'Line 3']

Alternatively, if you want each line to include the break sequence (CR,LF,CRLF), use the splitlines method with a True argument:

inputString.splitlines(True)  # --> ['Line 1\n', 'Line 2\n', 'Line 3']

Private Variables and Methods in Python

The double underscore. It mangles the name in such a way that it can't be accessed simply through __fieldName from outside the class, which is what you want to begin with if they're to be private. (Though it's still not very hard to access the field.)

class Foo:
    def __init__(self):
        self.__privateField = 4;
        print self.__privateField # yields 4 no problem

foo = Foo()
foo.__privateField
# AttributeError: Foo instance has no attribute '__privateField'

It will be accessible through _Foo__privateField instead. But it screams "I'M PRIVATE DON'T TOUCH ME", which is better than nothing.

SQL Server: Database stuck in "Restoring" state

What fixed it for me was

  1. stopping the instance
  2. creating a backup of the .mdf and .ldf files in the data folder
  3. Restart the instance
  4. delete the database stuck restoring
  5. put the .mdf and.ldf files back into the data folder
  6. Attach the instance to the .mdf and .ldf files

OS X Terminal Colors

When I worked on Mac OS X in the lab I was able to get the terminal colors from using Terminal (rather than X11) and then editing the profile (from the Mac menu bar). The interface is a bit odd on the colors, but you have to set the modified theme as default.

Further settings worked by editing .bashrc.

Building and running app via Gradle and Android Studio is slower than via Eclipse

Hardware

I'm sorry, but upgrading development station to SSD and tons of ram has probably a bigger influence than points below combined.

Tools versions

Increasing build performance has major priority for the development teams, so make sure you are using latest Gradle and Android Gradle Plugin.

Configuration File

Create a file named gradle.properties in whatever directory applies:

  • /home/<username>/.gradle/ (Linux)
  • /Users/<username>/.gradle/ (Mac)
  • C:\Users\<username>\.gradle (Windows)

Append:

# IDE (e.g. Android Studio) users:
# Settings specified in this file will override any Gradle settings
# configured through the IDE.

# For more details on how to configure your build environment visit
# http://www.gradle.org/docs/current/userguide/build_environment.html

# The Gradle daemon aims to improve the startup and execution time of Gradle.
# When set to true the Gradle daemon is to run the build.
# TODO: disable daemon on CI, since builds should be clean and reliable on servers
org.gradle.daemon=true

# Specifies the JVM arguments used for the daemon process.
# The setting is particularly useful for tweaking memory settings.
# https://medium.com/google-developers/faster-android-studio-builds-with-dex-in-process-5988ed8aa37e#.krd1mm27v
org.gradle.jvmargs=-Xmx5120m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8

# When configured, Gradle will run in incubating parallel mode.
# This option should only be used with decoupled projects. More details, visit
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
org.gradle.parallel=true

# Enables new incubating mode that makes Gradle selective when configuring projects. 
# Only relevant projects are configured which results in faster builds for large multi-projects.
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:configuration_on_demand
org.gradle.configureondemand=true

# Set to true or false to enable or disable the build cache. 
# If this parameter is not set, the build cache is disabled by default.
# http://tools.android.com/tech-docs/build-cache
android.enableBuildCache=true

Gradle properties works local if you place them at projectRoot\gradle.properties and globally if you place them at user_home\.gradle\gradle.properties. Properties applied if you run gradle tasks from console or directly from idea:

IDE Settings

It is possible to tweak Gradle-IntelliJ integration from the IDE settings GUI. Enabling "offline work" (check answer from yava below) will disable real network requests on every "sync gradle file".

IDE settings

Native multi-dex

One of the slowest steps of the apk build is converting java bytecode into single dex file. Enabling native multidex (minSdk 21 for debug builds only) will help the tooling to reduce an amount of work (check answer from Aksel Willgert below).

Dependencies

Prefer @aar dependencies over library sub-projects.

Search aar package on mavenCentral, jCenter or use jitpack.io to build any library from github. If you are not editing sources of the dependency library you should not build it every time with your project sources.

Antivirus

Consider to exclude project and cache files from antivirus scanning. This is obviously a trade off with security (don't try this at home!). But if you switch between branches a lot, then antivirus will rescan files before allowing gradle process to use it, which slows build time (in particular AndroidStudio sync project with gradle files and indexing tasks). Measure build time and process CPU with and without antivirus enabled to see if it is related.

Profiling a build

Gradle has built-in support for profiling projects. Different projects are using a different combination of plugins and custom scripts. Using --profile will help to find bottlenecks.

Create Table from JSON Data with angularjs and ng-repeat

The solution you are looking for is in Angular's official tutorial. In this tutorial Phones are loaded from a JSON file using Angulars $http service . In the code below we use $http.get to load a phones.json file saved in the phones directory:

var phonecatApp = angular.module('phonecatApp', []);   
phonecatApp.controller('PhoneListCtrl', function ($scope, $http) {
 $http.get('phones/phones.json').success(function(data) {
$scope.phones = data;
}); 
$scope.orderProp = 'age';
});

We then iterate over the phones:

<table>
  <tbody ng-repeat="i in phones">
    <tr><td>{{i.name}}</td><td>{{$index}}</td></tr>
    <tr ng-repeat="e in i.details">
       <td>{{$index}}</td>
       <td>{{e.foo}}</td>
       <td>{{e.bar}}</td></tr>
  </tbody>
</table>

java Compare two dates

java.util.Date class has before and after method to compare dates.

Date date1 = new Date();
Date date2 = new Date();

if(date1.before(date2)){
    //Do Something
}

if(date1.after(date2)){
    //Do Something else
}

List files ONLY in the current directory

You can use os.scandir(). New function in stdlib starts from Python 3.5.

import os

for entry in os.scandir('.'):
    if entry.is_file():
        print(entry.name)

Faster than os.listdir(). os.walk() implements os.scandir().

Trying to get property of non-object in

Your error

Notice: Trying to get property of non-object in C:\wamp\www\phone\pages\init.php on line 22

Your comment

@22 is <?php echo $sidemenu->mname."<br />";?>

$sidemenu is not an object, and you are trying to access one of its properties.

That is the reason for your error.

How to $http Synchronous call with AngularJS

var EmployeeController = ["$scope", "EmployeeService",
        function ($scope, EmployeeService) {
            $scope.Employee = {};
            $scope.Save = function (Employee) {                
                if ($scope.EmployeeForm.$valid) {
                    EmployeeService
                        .Save(Employee)
                        .then(function (response) {
                            if (response.HasError) {
                                $scope.HasError = response.HasError;
                                $scope.ErrorMessage = response.ResponseMessage;
                            } else {

                            }
                        })
                        .catch(function (response) {

                        });
                }
            }
        }]


var EmployeeService = ["$http", "$q",
            function ($http, $q) {
                var self = this;

                self.Save = function (employee) {
                    var deferred = $q.defer();                
                    $http
                        .post("/api/EmployeeApi/Create", angular.toJson(employee))
                        .success(function (response, status, headers, config) {
                            deferred.resolve(response, status, headers, config);
                        })
                        .error(function (response, status, headers, config) {
                            deferred.reject(response, status, headers, config);
                        });

                    return deferred.promise;
                };

Writing String to Stream and reading it back does not work

I think it would be a lot more productive to use a TextWriter, in this case a StreamWriter to write to the MemoryStream. After that, as other have said, you need to "rewind" the MemoryStream using something like stringAsStream.Position = 0L;.

stringAsStream = new MemoryStream();

// create stream writer with UTF-16 (Unicode) encoding to write to the memory stream
using(StreamWriter sWriter = new StreamWriter(stringAsStream, UnicodeEncoding.Unicode))
{
  sWriter.Write("Lorem ipsum.");
}
stringAsStream.Position = 0L; // rewind

Note that:

StreamWriter defaults to using an instance of UTF8Encoding unless specified otherwise. This instance of UTF8Encoding is constructed without a byte order mark (BOM)

Also, you don't have to create a new UnicodeEncoding() usually, since there's already one as a static member of the class for you to use in convenient utf-8, utf-16, and utf-32 flavors.

And then, finally (as others have said) you're trying to convert the bytes directly to chars, which they are not. If I had a memory stream and knew it was a string, I'd use a TextReader to get the string back from the bytes. It seems "dangerous" to me to mess around with the raw bytes.

jQuery autohide element after 5 seconds

This is how you can set the timeout after you click.

$(".selectorOnWhichEventCapture").on('click', function() {
    setTimeout(function(){
        $(".selector").doWhateverYouWantToDo();
    }, 5000);
});

//5000 = 5sec = 5000 milisec

String replacement in Objective-C

It also posible string replacement with stringByReplacingCharactersInRange:withString:

for (int i = 0; i < card.length - 4; i++) {

    if (![[card substringWithRange:NSMakeRange(i, 1)] isEqual:@" "]) {

        NSRange range = NSMakeRange(i, 1);
        card = [card stringByReplacingCharactersInRange:range withString:@"*"];

    }

} //out: **** **** **** 1234

Set windows environment variables with a batch file

@ECHO OFF

:: %HOMEDRIVE% = C:
:: %HOMEPATH% = \Users\Ruben
:: %system32% ??
:: No spaces in paths
:: Program Files > ProgramFiles
:: cls = clear screen
:: CMD reads the system environment variables when it starts. To re-read those variables you need to restart CMD
:: Use console 2 http://sourceforge.net/projects/console/


:: Assign all Path variables
SET PHP="%HOMEDRIVE%\wamp\bin\php\php5.4.16"
SET SYSTEM32=";%HOMEDRIVE%\Windows\System32"
SET ANT=";%HOMEDRIVE%%HOMEPATH%\Downloads\apache-ant-1.9.0-bin\apache-ant-1.9.0\bin"
SET GRADLE=";%HOMEDRIVE%\tools\gradle-1.6\bin;"
SET ADT=";%HOMEDRIVE%\tools\adt-bundle-windows-x86-20130219\eclipse\jre\bin"
SET ADTTOOLS=";%HOMEDRIVE%\tools\adt-bundle-windows-x86-20130219\sdk\tools"
SET ADTP=";%HOMEDRIVE%\tools\adt-bundle-windows-x86-20130219\sdk\platform-tools"
SET YII=";%HOMEDRIVE%\wamp\www\yii\framework"
SET NODEJS=";%HOMEDRIVE%\ProgramFiles\nodejs"
SET CURL=";%HOMEDRIVE%\tools\curl_734_0_ssl"
SET COMPOSER=";%HOMEDRIVE%\ProgramData\ComposerSetup\bin"
SET GIT=";%HOMEDRIVE%\Program Files\Git\cmd"

:: Set Path variable
setx PATH "%PHP%%SYSTEM32%%NODEJS%%COMPOSER%%YII%%GIT%" /m

:: Set Java variable
setx JAVA_HOME "%HOMEDRIVE%\ProgramFiles\Java\jdk1.7.0_21" /m

PAUSE

Error:java: javacTask: source release 8 requires target release 1.8

You need to go to the /.idea/compiler.xml and change target to required jdk level.

enter image description here

Repository access denied. access via a deployment key is read-only

I would like to re-emphasize the following:

  • You might have added the SSH key to your repository (e.g. ExampleRepo), but this is NOT where the SSH key goes.
  • It is meant to go into YOUR PROFILE. This is the small avatar on the bottom left corner of the screen. Here, you'll find a different place to put your SSH Keys (under Security) > then you add the key here instead.
  • If you accidentally put your SSH key into the repository (as opposed to your account), then delete the one in the repository.

Took me ages to realise, somehow even after reading the answers here it didn't click.

Format numbers in thousands (K) in Excel

Non-Americans take note! If you use Excel with "." as 1000 separator, you need to replace the "," with a "." in the formula, such as:

[>=1000]€ #.##0." K";[<=-1000]-€ #.##0." K";0

The code above will display € 62.123 as "€ 62 K".

Add space between two particular <td>s

you have to set cellpadding and cellspacing that's it.

<table cellpadding="5" cellspacing="5">
<tr> 
<td>One</td> 
<td>Two</td> 
<td>Three</td> 
<td>Four</td> 
</tr>
</table>

How do I set a Windows scheduled task to run in the background?

As noted by Mattias Nordqvist in the comments below, you can also select the radio button option "Run whether user is logged on or not". When saving the task, you will be prompted once for the user password. bambams noted that this wouldn't grant System permissions to the process, and also seems to hide the command window.


It's not an obvious solution, but to make a Scheduled Task run in the background, change the User running the task to "SYSTEM", and nothing will appear on your screen.

enter image description here

enter image description here

enter image description here

How to pretty print nested dictionaries?

Another option with yapf:

from pprint import pformat
from yapf.yapflib.yapf_api import FormatCode

dict_example = {'1': '1', '2': '2', '3': [1, 2, 3, 4, 5], '4': {'1': '1', '2': '2', '3': [1, 2, 3, 4, 5]}}
dict_string = pformat(dict_example)
formatted_code, _ = FormatCode(dict_string)

print(formatted_code)

Output:

{
    '1': '1',
    '2': '2',
    '3': [1, 2, 3, 4, 5],
    '4': {
        '1': '1',
        '2': '2',
        '3': [1, 2, 3, 4, 5]
    }
}

data.map is not a function

If you want to map an object you can use Lodash. Just make sure it's installed via NPM or Yarn and import it.

With Lodash:

Lodash provides a function _.mapValues to map the values and preserve the keys.

_.mapValues({ one: 1, two: 2, three: 3 }, function (v) { return v * 3; });

// => { one: 3, two: 6, three: 9 }

in_array() and multidimensional array

Here is my proposition based on json_encode() solution with :

  • case insensitive option
  • returning the count instead of true
  • anywhere in arrays (keys and values)

If word not found, it still returns 0 equal to false.

function in_array_count($needle, $haystack, $caseSensitive = true) {
    if(!$caseSensitive) {
        return substr_count(strtoupper(json_encode($haystack)), strtoupper($needle));
    }
    return substr_count(json_encode($haystack), $needle);
}

Hope it helps.

How do I print bytes as hexadecimal?

Use C++ streams and restore state afterwards

This is a variation of How do I print bytes as hexadecimal? but:

main.cpp

#include <iomanip>
#include <iostream>

int main() {
    int array[] = {0, 0x8, 0x10, 0x18};
    constexpr size_t size = sizeof(array) / sizeof(array[0]);

    // Sanity check decimal print.
    for (size_t i = 0; i < size; ++i)
        std::cout << array[i] << " ";
    std::cout << std::endl;

    // Hex print and restore default afterwards.
    std::ios cout_state(nullptr);
    cout_state.copyfmt(std::cout);
    std::cout << std::hex << std::setfill('0') << std::setw(2);
    for (size_t i = 0; i < size; ++i)
        std::cout << array[i] << " ";
    std::cout << std::endl;
    std::cout.copyfmt(cout_state);

    // Check that cout state was restored.
    for (size_t i = 0; i < size; ++i)
        std::cout << array[i] << " ";
    std::cout << std::endl;
}

Compile and run:

g++ -o main.out -std=c++11 main.cpp
./main.out

Output:

0 8 16 24 
00 8 10 18 
0 8 16 24

Tested on Ubuntu 16.04, GCC 6.4.0.

org.hibernate.MappingException: Unknown entity

you should add all the entity files in the .addAnnotatedClass(Class) method, if the class needs to be auto discovered.

use this link, it might help..

http://docs.jboss.org/hibernate/stable/core/api/org/hibernate/cfg/AnnotationConfiguration.html

Angular: Cannot find a differ supporting object '[object Object]'

I received this error in my code because I'd not run JSON.parse(result).

So my result was a string instead of an array of objects.

i.e. I got:

"[{},{}]" 

instead of:

[{},{}]

import { Storage } from '@ionic/storage';
...
private static readonly SERVER = 'server';
...
getStorage(): Promise {
  return this.storage.get(LoginService.SERVER);
}
...
this.getStorage()
  .then((value) => {
     let servers: Server[] = JSON.parse(value) as Server[];
                   }
  );

Search for one value in any column of any table inside a database

How to search all columns of all tables in a database for a keyword?

http://vyaskn.tripod.com/search_all_columns_in_all_tables.htm

EDIT: Here's the actual T-SQL, in case of link rot:

CREATE PROC SearchAllTables
(
@SearchStr nvarchar(100)
)
AS
BEGIN

-- Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.
-- Purpose: To search all columns of all tables for a given search string
-- Written by: Narayana Vyas Kondreddi
-- Site: http://vyaskn.tripod.com
-- Tested on: SQL Server 7.0 and SQL Server 2000
-- Date modified: 28th July 2002 22:50 GMT


CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))

SET NOCOUNT ON

DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

WHILE @TableName IS NOT NULL
BEGIN
    SET @ColumnName = ''
    SET @TableName = 
    (
        SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
        FROM    INFORMATION_SCHEMA.TABLES
        WHERE       TABLE_TYPE = 'BASE TABLE'
            AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
            AND OBJECTPROPERTY(
                    OBJECT_ID(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0
    )

    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
    BEGIN
        SET @ColumnName =
        (
            SELECT MIN(QUOTENAME(COLUMN_NAME))
            FROM    INFORMATION_SCHEMA.COLUMNS
            WHERE       TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND TABLE_NAME  = PARSENAME(@TableName, 1)
                AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
                AND QUOTENAME(COLUMN_NAME) > @ColumnName
        )

        IF @ColumnName IS NOT NULL
        BEGIN
            INSERT INTO #Results
            EXEC
            (
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) 
                FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
            )
        END
    END 
END

SELECT ColumnName, ColumnValue FROM #Results
 END

How do I configure HikariCP in my Spring Boot app in my application.properties files?

I came across HikariCP and I was amazed by the benchmarks and I wanted to try it instead of my default choice C3P0 and to my surprise I struggled to get the configurations right probably because the configurations differ based on what combination of tech stack you are using.

I have setup Spring Boot project with JPA, Web, Security starters (Using Spring Initializer) to use PostgreSQL as a database with HikariCP as connection pooling.
I have used Gradle as build tool and I would like to share what worked for me for the following assumptions:

  1. Spring Boot Starter JPA (Web & Security - optional)
  2. Gradle build too
  3. PostgreSQL running and setup with a database (i.e. schema, user, db)

You need the following build.gradle if you are using Gradle or equivalent pom.xml if you are using maven

buildscript {
    ext {
        springBootVersion = '1.5.8.RELEASE'
    }
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'war'

group = 'com'
version = '1.0'
sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies {
    compile('org.springframework.boot:spring-boot-starter-aop')

    // Exclude the tomcat-jdbc since it's used as default for connection pooling
    // This can also be achieved by setting the spring.datasource.type to HikariCP 
    // datasource see application.properties below
    compile('org.springframework.boot:spring-boot-starter-data-jpa') {
        exclude group: 'org.apache.tomcat', module: 'tomcat-jdbc'
    }
    compile('org.springframework.boot:spring-boot-starter-security')
    compile('org.springframework.boot:spring-boot-starter-web')
    runtime('org.postgresql:postgresql')
    testCompile('org.springframework.boot:spring-boot-starter-test')
    testCompile('org.springframework.security:spring-security-test')

    // Download HikariCP but, exclude hibernate-core to avoid version conflicts
    compile('com.zaxxer:HikariCP:2.5.1') {
        exclude group: 'org.hibernate', module: 'hibernate-core'
    }

    // Need this in order to get the HikariCPConnectionProvider
    compile('org.hibernate:hibernate-hikaricp:5.2.11.Final') {
        exclude group: 'com.zaxxer', module: 'HikariCP'
        exclude group: 'org.hibernate', module: 'hibernate-core'
    }
}

There are a bunch of excludes in the above build.gradle and that's because

  1. First exclude, instructs gradle that exclude the jdbc-tomcat connection pool when downloading the spring-boot-starter-data-jpa dependencies. This can be achieved by setting up the spring.datasource.type=com.zaxxer.hikari.HikariDataSource also but, I don't want an extra dependency if I don't need it
  2. Second exclude, instructs gradle to exclude hibernate-core when downloading com.zaxxer dependency and that's because hibernate-core is already downloaded by Spring Boot and we don't want to end up with different versions.
  3. Third exclude, instructs gradle to exclude hibernate-core when downloading hibernate-hikaricp module which is needed in order to make HikariCP use org.hibernate.hikaricp.internal.HikariCPConnectionProvider as connection provider instead of deprecated com.zaxxer.hikari.hibernate.HikariConnectionProvider

Once I figured out the build.gradle and what to keep and what to not, I was ready to copy/paste a datasource configuration into my application.properties and expected everything to work with flying colors but, not really and I stumbled upon the following issues

  • Spring boot failing to find out database details (i.e. url, driver) hence, not able to setup jpa and hibernate (because I didn't name the property key values right)
  • HikariCP falling back to com.zaxxer.hikari.hibernate.HikariConnectionProvider
  • After instructing Spring to use new connection-provider for when auto-configuring hibernate/jpa then HikariCP failed because it was looking for some key/value in the application.properties and was complaining about dataSource, dataSourceClassName, jdbcUrl. I had to debug into HikariConfig, HikariConfigurationUtil, HikariCPConnectionProvider and found out that HikariCP could not find the properties from application.properties because it was named differently.

Anyway, this is where I had to rely on trial and error and make sure that HikariCP is able to pick the properties (i.e. data source that's db details, as well as pooling properties) as well as Sping Boot behave as expected and I ended up with the following application.properties file.

server.contextPath=/
debug=true

# Spring data source needed for Spring boot to behave
# Pre Spring Boot v2.0.0.M6 without below Spring Boot defaults to tomcat-jdbc connection pool included 
# in spring-boot-starter-jdbc and as compiled dependency under spring-boot-starter-data-jpa
spring.datasource.type=com.zaxxer.hikari.HikariDataSource
spring.datasource.url=jdbc:postgresql://localhost:5432/somedb
spring.datasource.username=dbuser
spring.datasource.password=dbpassword

# Hikari will use the above plus the following to setup connection pooling
spring.datasource.hikari.minimumIdle=5
spring.datasource.hikari.maximumPoolSize=20
spring.datasource.hikari.idleTimeout=30000
spring.datasource.hikari.poolName=SpringBootJPAHikariCP
spring.datasource.hikari.maxLifetime=2000000
spring.datasource.hikari.connectionTimeout=30000

# Without below HikariCP uses deprecated com.zaxxer.hikari.hibernate.HikariConnectionProvider
# Surprisingly enough below ConnectionProvider is in hibernate-hikaricp dependency and not hibernate-core
# So you need to pull that dependency but, make sure to exclude it's transitive dependencies or you will end up 
# with different versions of hibernate-core 
spring.jpa.hibernate.connection.provider_class=org.hibernate.hikaricp.internal.HikariCPConnectionProvider

# JPA specific configs
spring.jpa.properties.hibernate.show_sql=true
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.properties.hibernate.use_sql=true
spring.jpa.properties.hibernate.id.new_generator_mappings=false
spring.jpa.properties.hibernate.default_schema=dbschema
spring.jpa.properties.hibernate.search.autoregister_listeners=false
spring.jpa.properties.hibernate.bytecode.use_reflection_optimizer=false

# Enable logging to verify that HikariCP is used, the second entry is specific to HikariCP
logging.level.org.hibernate.SQL=DEBUG
logging.level.com.zaxxer.hikari.HikariConfig=DEBUG
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE 

As shown above the configurations are divided into categories based on following naming patterns

  • spring.datasource.x (Spring auto-configure will pick these, so will HikariCP)
  • spring.datasource.hikari.x (HikariCP picks these to setup the pool, make a note of the camelCase field names)
  • spring.jpa.hibernate.connection.provider_class (Instructs Spring to use new HibernateConnectionProvider)
  • spring.jpa.properties.hibernate.x (Used by Spring to auto-configure JPA, make a note of the field names with underscores)

It's hard to come across a tutorial or post or some resource that shows how the above properties file is used and how the properties should be named. Well, there you have it.

Throwing the above application.properties with build.gradle (or at least similar) into a Spring Boot JPA project version (1.5.8) should work like a charm and connect to your pre-configured database (i.e. in my case it's PostgreSQL that both HikariCP & Spring figure out from the spring.datasource.url on which database driver to use).

I did not see the need to create a DataSource bean and that's because Spring Boot is capable of doing everything for me just by looking into application.properties and that's neat.

The article in HikariCP's github wiki shows how to setup Spring Boot with JPA but, lacks explanation and details.

The above two file is also availble as a public gist https://gist.github.com/rhamedy/b3cb936061cc03acdfe21358b86a5bc6

Best practices with STDIN in Ruby?

I am not quite sure what you need, but I would use something like this:

#!/usr/bin/env ruby

until ARGV.empty? do
  puts "From arguments: #{ARGV.shift}"
end

while a = gets
  puts "From stdin: #{a}"
end

Note that because ARGV array is empty before first gets, Ruby won't try to interpret argument as text file from which to read (behaviour inherited from Perl).

If stdin is empty or there is no arguments, nothing is printed.

Few test cases:

$ cat input.txt | ./myprog.rb
From stdin: line 1
From stdin: line 2

$ ./myprog.rb arg1 arg2 arg3
From arguments: arg1
From arguments: arg2
From arguments: arg3
hi!
From stdin: hi!

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

The problem with the script is that the environment used for the script is not the same as the one used for your tests, so setting the environment variables there does nothing for your tests.

To properly set the variable you need to set it in Jenkins. Go to Manage Jenkins>Manage Nodes>Master>Configure. Check the Environment variables check box, then enter DISPLAY in the name box, and set the value to :1.0.

Additionally you'll need to set permissions, try disabling your xhost access controls using xhost + in the terminal.

Why does NULL = NULL evaluate to false in SQL server

null is unknown in sql so we cant expect two unknowns to be same.

However you can get that behavior by setting ANSI_NULLS to Off(its On by Default) You will be able to use = operator for nulls

SET ANSI_NULLS off
if null=null
print 1
else 
print 2
set ansi_nulls on
if null=null
print 1
else 
print 2

window.location.href not working

The browser is still submitting the form after your code runs.

Add return false; to the handler to prevent that.

how does Request.QueryString work?

Request.QueryString["pID"];

Here Request is a object that retrieves the values that the client browser passed to the server during an HTTP request and QueryString is a collection is used to retrieve the variable values in the HTTP query string.

READ MORE@ http://msdn.microsoft.com/en-us/library/ms524784(v=vs.90).aspx

How to access private data members outside the class without making "friend"s?

You can't. That member is private, it's not visible outside the class. That's the whole point of the public/protected/private modifiers.

(You could probably use dirty pointer tricks though, but my guess is that you'd enter undefined behavior territory pretty fast.)

TypeError: 'int' object is not subscriptable

Just to be clear, all the answers so far are correct, but the reasoning behind them is not explained very well.

The sumall variable is not yet a string. Parentheticals will not convert to a string (e.g. summ = (int(birthday[0])+int(birthday[1])) still returns an integer. It looks like you most likely intended to type str((int(sumall[0])+int(sumall[1]))), but forgot to. The reason the str() function fixes everything is because it converts anything in it compatible to a string.

Setting paper size in FPDF

/*$mpdf = new mPDF('',    // mode - default ''
 '',    // format - A4, for example, default ''
 0,     // font size - default 0
 '',    // default font family
 15,    // margin_left
 15,    // margin right
 16,     // margin top
 16,    // margin bottom
 9,     // margin header
 9,     // margin footer
 'L');  // L - landscape, P - portrait*/

Converting String to Double in Android

  kw=(EditText)findViewById(R.id.kw);
    btn=(Button)findViewById(R.id.btn);
    cost=(TextView )findViewById(R.id.cost);


            btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) { cst =  Double.valueOf(kw.getText().toString());
            cst = cst*0.551;
            cost.setText(cst.toString());
        }
    });

how to make a full screen div, and prevent size to be changed by content?

Or even just:

<div id="full-size">
  Your contents go here
</div>
html,body{ margin:0; padding:0; height:100%; width:100%; }
#full-size{
  height:100%;
  width:100%;
  overflow:hidden; /* or overflow:auto; if you want scrollbars */
}

(html, body can be set to like.. 95%-99% or some such to account for slight inconsistencies in margins, etc.)

What is the difference between atomic / volatile / synchronized?

volatile:

volatile is a keyword. volatile forces all threads to get latest value of the variable from main memory instead of cache. No locking is required to access volatile variables. All threads can access volatile variable value at same time.

Using volatile variables reduces the risk of memory consistency errors, because any write to a volatile variable establishes a happens-before relationship with subsequent reads of that same variable.

This means that changes to a volatile variable are always visible to other threads. What's more, it also means that when a thread reads a volatile variable, it sees not just the latest change to the volatile, but also the side effects of the code that led up the change.

When to use: One thread modifies the data and other threads have to read latest value of data. Other threads will take some action but they won't update data.

AtomicXXX:

AtomicXXX classes support lock-free thread-safe programming on single variables. These AtomicXXX classes (like AtomicInteger) resolves memory inconsistency errors / side effects of modification of volatile variables, which have been accessed in multiple threads.

When to use: Multiple threads can read and modify data.

synchronized:

synchronized is keyword used to guard a method or code block. By making method as synchronized has two effects:

  1. First, it is not possible for two invocations of synchronized methods on the same object to interleave. When one thread is executing a synchronized method for an object, all other threads that invoke synchronized methods for the same object block (suspend execution) until the first thread is done with the object.

  2. Second, when a synchronized method exits, it automatically establishes a happens-before relationship with any subsequent invocation of a synchronized method for the same object. This guarantees that changes to the state of the object are visible to all threads.

When to use: Multiple threads can read and modify data. Your business logic not only update the data but also executes atomic operations

AtomicXXX is equivalent of volatile + synchronized even though the implementation is different. AmtomicXXX extends volatile variables + compareAndSet methods but does not use synchronization.

Related SE questions:

Difference between volatile and synchronized in Java

Volatile boolean vs AtomicBoolean

Good articles to read: ( Above content is taken from these documentation pages)

https://docs.oracle.com/javase/tutorial/essential/concurrency/sync.html

https://docs.oracle.com/javase/tutorial/essential/concurrency/atomic.html

https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/package-summary.html

XAMPP - Error: MySQL shutdown unexpectedly

If your skype is open, Quit skype and try,

or

Go to your xampp/wamp installed, search for httpd.conf. Open that file using textpad/notepad, search for Listen or 80 , update listen port to 8081 and save the file. Restart xampp/wamp, start the servers.


or
follow below steps in skype enter image description here

Parse date string and change format

Just for the sake of completion: when parsing a date using strptime() and the date contains the name of a day, month, etc, be aware that you have to account for the locale.

It's mentioned as a footnote in the docs as well.

As an example:

import locale
print(locale.getlocale())

>> ('nl_BE', 'ISO8859-1')

from datetime import datetime
datetime.strptime('6-Mar-2016', '%d-%b-%Y').strftime('%Y-%m-%d')

>> ValueError: time data '6-Mar-2016' does not match format '%d-%b-%Y'

locale.setlocale(locale.LC_ALL, 'en_US')
datetime.strptime('6-Mar-2016', '%d-%b-%Y').strftime('%Y-%m-%d')

>> '2016-03-06'

CSS Box Shadow - Top and Bottom Only

As Kristian has pointed out, good control over z-values will often solve your problems.

If that does not work you can take a look at CSS Box Shadow Bottom Only on using overflow hidden to hide excess shadow.

I would also have in mind that the box-shadow property can accept a comma-separated list of shadows like this:

box-shadow: 0px 10px 5px #888, 0px -10px 5px #888;

This will give you some control over the "amount" of shadow in each direction.

Have a look at http://www.css3.info/preview/box-shadow/ for more information about box-shadow.

Hope this was what you were looking for!

How do I do a multi-line string in node.js?

node v4 and current versions of node

As of ES6 (and so versions of Node greater than v4), a new "template literal" intrinsic type was added to Javascript (denoted by back-ticks "`") which can also be used to construct multi-line strings, as in:

`this is a 
single string`

which evaluates to: 'this is a\nsingle string'.

Note that the newline at the end of the first line is included in the resulting string.

Template literals were added to allow programmers to construct strings where values or code could be directly injected into a string literal without having to use util.format or other templaters, as in:

let num=10;

console.log(`the result of ${num} plus ${num} is ${num + num}.`);

which will print "the result of 10 plus 10 is 20." to the console.

Older versions of node

Older version of node can use a "line continuation" character allowing you to write multi-line strings such as:

'this is a \
single string'

which evaluates to: 'this is a single string'.

Note that the newline at the end of the first line is not included in the resulting string.

How to calculate an age based on a birthday?

I do it like this:

(Shortened the code a bit)

public struct Age
{
    public readonly int Years;
    public readonly int Months;
    public readonly int Days;

}

public Age( int y, int m, int d ) : this()
{
    Years = y;
    Months = m;
    Days = d;
}

public static Age CalculateAge ( DateTime birthDate, DateTime anotherDate )
{
    if( startDate.Date > endDate.Date )
        {
            throw new ArgumentException ("startDate cannot be higher then endDate", "startDate");
        }

        int years = endDate.Year - startDate.Year;
        int months = 0;
        int days = 0;

        // Check if the last year, was a full year.
        if( endDate < startDate.AddYears (years) && years != 0 )
        {
            years--;
        }

        // Calculate the number of months.
        startDate = startDate.AddYears (years);

        if( startDate.Year == endDate.Year )
        {
            months = endDate.Month - startDate.Month;
        }
        else
        {
            months = ( 12 - startDate.Month ) + endDate.Month;
        }

        // Check if last month was a complete month.
        if( endDate < startDate.AddMonths (months) && months != 0 )
        {
            months--;
        }

        // Calculate the number of days.
        startDate = startDate.AddMonths (months);

        days = ( endDate - startDate ).Days;

        return new Age (years, months, days);
}

// Implement Equals, GetHashCode, etc... as well
// Overload equality and other operators, etc...

}

How can I update a single row in a ListView?

I found the answer, thanks to your information Michelle. You can indeed get the right view using View#getChildAt(int index). The catch is that it starts counting from the first visible item. In fact, you can only get the visible items. You solve this with ListView#getFirstVisiblePosition().

Example:

private void updateView(int index){
    View v = yourListView.getChildAt(index - 
        yourListView.getFirstVisiblePosition());

    if(v == null)
       return;

    TextView someText = (TextView) v.findViewById(R.id.sometextview);
    someText.setText("Hi! I updated you manually!");
}

JQuery .hasClass for multiple values in an if statement

You could use is() instead of hasClass():

if ($('html').is('.m320, .m768')) { ... }

What's the most efficient way to test two integer ranges for overlap?

What does it mean for the ranges to overlap? It means there exists some number C which is in both ranges, i.e.

x1 <= C <= x2

and

y1 <= C <= y2

Now, if we are allowed to assume that the ranges are well-formed (so that x1 <= x2 and y1 <= y2) then it is sufficient to test

x1 <= y2 && y1 <= x2

What's the difference between fill_parent and wrap_content?

Either attribute can be applied to View's (visual control) horizontal or vertical size. It's used to set a View or Layouts size based on either it's contents or the size of it's parent layout rather than explicitly specifying a dimension.

fill_parent (deprecated and renamed MATCH_PARENT in API Level 8 and higher)

Setting the layout of a widget to fill_parent will force it to expand to take up as much space as is available within the layout element it's been placed in. It's roughly equivalent of setting the dockstyle of a Windows Form Control to Fill.

Setting a top level layout or control to fill_parent will force it to take up the whole screen.

wrap_content

Setting a View's size to wrap_content will force it to expand only far enough to contain the values (or child controls) it contains. For controls -- like text boxes (TextView) or images (ImageView) -- this will wrap the text or image being shown. For layout elements it will resize the layout to fit the controls / layouts added as its children.

It's roughly the equivalent of setting a Windows Form Control's Autosize property to True.

Online Documentation

There's some details in the Android code documentation here.

Is the size of C "int" 2 bytes or 4 bytes?

Is the size of C “int” 2 bytes or 4 bytes?

Does an Integer variable in C occupy 2 bytes or 4 bytes?

C allows "bytes" to be something other than 8 bits per "byte".

CHAR_BIT number of bits for smallest object that is not a bit-field (byte) C11dr §5.2.4.2.1 1

A value of something than 8 is increasingly uncommon. For maximum portability, use CHAR_BIT rather than 8. The size of an int in bits in C is sizeof(int) * CHAR_BIT.

#include <limits.h>
printf("(int) Bit size %zu\n", sizeof(int) * CHAR_BIT);

What are the factors that it depends on?

The int bit size is commonly 32 or 16 bits. C specified minimum ranges:

minimum value for an object of type int INT_MIN -32767
maximum value for an object of type int INT_MAX +32767
C11dr §5.2.4.2.1 1

The minimum range for int forces the bit size to be at least 16 - even if the processor was "8-bit". A size like 64 bits is seen in specialized processors. Other values like 18, 24, 36, etc. have occurred on historic platforms or are at least theoretically possible. Modern coding rarely worries about non-power-of-2 int bit sizes.

The computer's processor and architecture drive the int bit size selection.

Yet even with 64-bit processors, the compiler's int size may be 32-bit for compatibility reasons as large code bases depend on int being 32-bit (or 32/16).

Pass props to parent component in React.js

Edit: see the end examples for ES6 updated examples.

This answer simply handle the case of direct parent-child relationship. When parent and child have potentially a lot of intermediaries, check this answer.

Other solutions are missing the point

While they still work fine, other answers are missing something very important.

Is there not a simple way to pass a child's props to its parent using events, in React.js?

The parent already has that child prop!: if the child has a prop, then it is because its parent provided that prop to the child! Why do you want the child to pass back the prop to the parent, while the parent obviously already has that prop?

Better implementation

Child: it really does not have to be more complicated than that.

var Child = React.createClass({
  render: function () {
    return <button onClick={this.props.onClick}>{this.props.text}</button>;
  },
});

Parent with single child: using the value it passes to the child

var Parent = React.createClass({
  getInitialState: function() {
     return {childText: "Click me! (parent prop)"};
  },
  render: function () {
    return (
      <Child onClick={this.handleChildClick} text={this.state.childText}/>
    );
  },
  handleChildClick: function(event) {
     // You can access the prop you pass to the children 
     // because you already have it! 
     // Here you have it in state but it could also be
     //  in props, coming from another parent.
     alert("The Child button text is: " + this.state.childText);
     // You can also access the target of the click here 
     // if you want to do some magic stuff
     alert("The Child HTML is: " + event.target.outerHTML);
  }
});

JsFiddle

Parent with list of children: you still have everything you need on the parent and don't need to make the child more complicated.

var Parent = React.createClass({
  getInitialState: function() {
     return {childrenData: [
         {childText: "Click me 1!", childNumber: 1},
         {childText: "Click me 2!", childNumber: 2}
     ]};
  },
  render: function () {
    var children = this.state.childrenData.map(function(childData,childIndex) {
        return <Child onClick={this.handleChildClick.bind(null,childData)} text={childData.childText}/>;
    }.bind(this));
    return <div>{children}</div>;
  },

  handleChildClick: function(childData,event) {
     alert("The Child button data is: " + childData.childText + " - " + childData.childNumber);
     alert("The Child HTML is: " + event.target.outerHTML);
  }
});

JsFiddle

It is also possible to use this.handleChildClick.bind(null,childIndex) and then use this.state.childrenData[childIndex]

Note we are binding with a null context because otherwise React issues a warning related to its autobinding system. Using null means you don't want to change the function context. See also.

About encapsulation and coupling in other answers

This is for me a bad idea in term of coupling and encapsulation:

var Parent = React.createClass({
  handleClick: function(childComponent) {
     // using childComponent.props
     // using childComponent.refs.button
     // or anything else using childComponent
  },
  render: function() {
    <Child onClick={this.handleClick} />
  }
});

Using props: As I explained above, you already have the props in the parent so it's useless to pass the whole child component to access props.

Using refs: You already have the click target in the event, and in most case this is enough. Additionnally, you could have used a ref directly on the child:

<Child ref="theChild" .../>

And access the DOM node in the parent with

React.findDOMNode(this.refs.theChild)

For more advanced cases where you want to access multiple refs of the child in the parent, the child could pass all the dom nodes directly in the callback.

The component has an interface (props) and the parent should not assume anything about the inner working of the child, including its inner DOM structure or which DOM nodes it declares refs for. A parent using a ref of a child means that you tightly couple the 2 components.

To illustrate the issue, I'll take this quote about the Shadow DOM, that is used inside browsers to render things like sliders, scrollbars, video players...:

They created a boundary between what you, the Web developer can reach and what’s considered implementation details, thus inaccessible to you. The browser however, can traipse across this boundary at will. With this boundary in place, they were able to build all HTML elements using the same good-old Web technologies, out of the divs and spans just like you would.

The problem is that if you let the child implementation details leak into the parent, you make it very hard to refactor the child without affecting the parent. This means as a library author (or as a browser editor with Shadow DOM) this is very dangerous because you let the client access too much, making it very hard to upgrade code without breaking retrocompatibility.

If Chrome had implemented its scrollbar letting the client access the inner dom nodes of that scrollbar, this means that the client may have the possibility to simply break that scrollbar, and that apps would break more easily when Chrome perform its auto-update after refactoring the scrollbar... Instead, they only give access to some safe things like customizing some parts of the scrollbar with CSS.

About using anything else

Passing the whole component in the callback is dangerous and may lead novice developers to do very weird things like calling childComponent.setState(...) or childComponent.forceUpdate(), or assigning it new variables, inside the parent, making the whole app much harder to reason about.


Edit: ES6 examples

As many people now use ES6, here are the same examples for ES6 syntax

The child can be very simple:

const Child = ({
  onClick, 
  text
}) => (
  <button onClick={onClick}>
    {text}
  </button>
)

The parent can be either a class (and it can eventually manage the state itself, but I'm passing it as props here:

class Parent1 extends React.Component {
  handleChildClick(childData,event) {
     alert("The Child button data is: " + childData.childText + " - " + childData.childNumber);
     alert("The Child HTML is: " + event.target.outerHTML);
  }
  render() {
    return (
      <div>
        {this.props.childrenData.map(child => (
          <Child
            key={child.childNumber}
            text={child.childText} 
            onClick={e => this.handleChildClick(child,e)}
          />
        ))}
      </div>
    );
  }
}

But it can also be simplified if it does not need to manage state:

const Parent2 = ({childrenData}) => (
  <div>
     {childrenData.map(child => (
       <Child
         key={child.childNumber}
         text={child.childText} 
         onClick={e => {
            alert("The Child button data is: " + child.childText + " - " + child.childNumber);
                    alert("The Child HTML is: " + e.target.outerHTML);
         }}
       />
     ))}
  </div>
)

JsFiddle


PERF WARNING (apply to ES5/ES6): if you are using PureComponent or shouldComponentUpdate, the above implementations will not be optimized by default because using onClick={e => doSomething()}, or binding directly during the render phase, because it will create a new function everytime the parent renders. If this is a perf bottleneck in your app, you can pass the data to the children, and reinject it inside "stable" callback (set on the parent class, and binded to this in class constructor) so that PureComponent optimization can kick in, or you can implement your own shouldComponentUpdate and ignore the callback in the props comparison check.

You can also use Recompose library, which provide higher order components to achieve fine-tuned optimisations:

// A component that is expensive to render
const ExpensiveComponent = ({ propA, propB }) => {...}

// Optimized version of same component, using shallow comparison of props
// Same effect as React's PureRenderMixin
const OptimizedComponent = pure(ExpensiveComponent)

// Even more optimized: only updates if specific prop keys have changed
const HyperOptimizedComponent = onlyUpdateForKeys(['propA', 'propB'])(ExpensiveComponent)

In this case you could optimize the Child component by using:

const OptimizedChild = onlyUpdateForKeys(['text'])(Child)

Selenium WebDriver: Wait for complex page with JavaScript to load

For the nodejs Selenium library, I used the following snippet. In my case, I was looking for two objects that are added to the window, which in this example are <SOME PROPERTY>, 10000 is the timeout milliseconds, <NEXT STEP HERE> is what happens after the properties are found on the window.

driver.wait( driver => {
    return driver.executeScript( 'if(window.hasOwnProperty(<SOME PROPERTY>) && window.hasOwnProperty(<SOME PROPERTY>)) return true;' ); }, 10000).then( ()=>{
        <NEXT STEP HERE>
}).catch(err => { 
    console.log("looking for window properties", err);
});

Java: splitting the filename into a base and extension

Maybe you could use String#split

To answer your comment:

I'm not sure if there can be more than one . in a filename, but whatever, even if there are more dots you can use the split. Consider e.g. that:

String input = "boo.and.foo";

String[] result = input.split(".");

This will return an array containing:

{ "boo", "and", "foo" }

So you will know that the last index in the array is the extension and all others are the base.

Combine two columns and add into one new column

Did you check the string concatenation function? Something like:

update table_c set column_a = column_b || column_c 

should work. More here

Select records from today, this week, this month php mysql

You can do same thing using single query

SELECT sum(if(DATE(dDate)=DATE(CURRENT_TIMESTAMP),earning,null)) astodays,
       sum(if(YEARWEEK(dDate)=YEARWEEK(CURRENT_DATE),earning,null)) as weeks, 
       IF((MONTH(dDate) = MONTH(CURRENT_TIMESTAMP()) AND YEAR(dDate) = YEAR(CURRENT_TIMESTAMP())),sum(earning),0) AS months,
       IF(YEAR(dDate) = YEAR(CURRENT_TIMESTAMP()),sum(earning),0) AS years, 
       sum(fAdminFinalEarning) as total_earning FROM `earning`

Hope this works.

How to find if element with specific id exists or not

getElementById

Return Value: An Element Object, representing an element with the specified ID. Returns null if no elements with the specified ID exists see: https://www.w3schools.com/jsref/met_document_getelementbyid.asp

Truthy vs Falsy

In JavaScript, a truthy value is a value that is considered true when evaluated in a Boolean context. All values are truthy unless they are defined as falsy (i.e., except for false, 0, "", null, undefined, and NaN). see: https://developer.mozilla.org/en-US/docs/Glossary/Truthy

When the dom element is not found in the document it will return null. null is a Falsy and can be used as boolean expression in the if statement.

var myElement = document.getElementById("myElement");
if(myElement){
  // Element exists
}

How is __eq__ handled in Python and in what order?

When Python2.x sees a == b, it tries the following.

  • If type(b) is a new-style class, and type(b) is a subclass of type(a), and type(b) has overridden __eq__, then the result is b.__eq__(a).
  • If type(a) has overridden __eq__ (that is, type(a).__eq__ isn't object.__eq__), then the result is a.__eq__(b).
  • If type(b) has overridden __eq__, then the result is b.__eq__(a).
  • If none of the above are the case, Python repeats the process looking for __cmp__. If it exists, the objects are equal iff it returns zero.
  • As a final fallback, Python calls object.__eq__(a, b), which is True iff a and b are the same object.

If any of the special methods return NotImplemented, Python acts as though the method didn't exist.

Note that last step carefully: if neither a nor b overloads ==, then a == b is the same as a is b.


From https://eev.ee/blog/2012/03/24/python-faq-equality/

Expected block end YAML error

This error also occurs if you use four-space instead of two-space indentation.

e.g., the following would throw the error:

fields:
    - metadata: {}
        name: colName
        nullable: true

whereas changing indentation to two-spaces would fix it:

fields:
  - metadata: {}
    name: colName
    nullable: true

How to change the blue highlight color of a UITableViewCell?

Based on @user's answer, you can just add this extension anywhere in your app code and have your selection color directly in storyboard editor for every cells of your app :

@IBDesignable extension UITableViewCell {
    @IBInspectable var selectedColor: UIColor? {
        set {
            if let color = newValue {
                selectedBackgroundView = UIView()
                selectedBackgroundView!.backgroundColor = color
            } else {
                selectedBackgroundView = nil
            }
        }
        get {
            return selectedBackgroundView?.backgroundColor
        }
    }
}

UITableViewCell selection color in storyboard

convert epoch time to date

EDIT: Okay, so you don't want your local time (which isn't Australia) to contribute to the result, but instead the Australian time zone. Your existing code should be absolutely fine then, although Sydney is currently UTC+11, not UTC+10.. Short but complete test app:

import java.util.*;
import java.text.*;

public class Test {
    public static void main(String[] args) throws InterruptedException {
        Date date = new Date(1318386508000L);
        DateFormat format = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
        format.setTimeZone(TimeZone.getTimeZone("Etc/UTC"));
        String formatted = format.format(date);
        System.out.println(formatted);
        format.setTimeZone(TimeZone.getTimeZone("Australia/Sydney"));
        formatted = format.format(date);
        System.out.println(formatted);
    }
}

Output:

12/10/2011 02:28:28
12/10/2011 13:28:28

I would also suggest you start using Joda Time which is simply a much nicer date/time API...

EDIT: Note that if your system doesn't know about the Australia/Sydney time zone, it would show UTC. For example, if I change the code about to use TimeZone.getTimeZone("blah/blah") it will show the UTC value twice. I suggest you print TimeZone.getTimeZone("Australia/Sydney").getDisplayName() and see what it says... and check your code for typos too :)

Using RegEx in SQL Server

You will have to build a CLR procedure that provides regex functionality, as this article illustrates.

Their example function uses VB.NET:

Imports System
Imports System.Data.Sql
Imports Microsoft.SqlServer.Server
Imports System.Data.SqlTypes
Imports System.Runtime.InteropServices
Imports System.Text.RegularExpressions
Imports System.Collections 'the IEnumerable interface is here  


Namespace SimpleTalk.Phil.Factor
    Public Class RegularExpressionFunctions
        'RegExIsMatch function
        <SqlFunction(IsDeterministic:=True, IsPrecise:=True)> _
        Public Shared Function RegExIsMatch( _
                                            ByVal pattern As SqlString, _
                                            ByVal input As SqlString, _
                                            ByVal Options As SqlInt32) As SqlBoolean
            If (input.IsNull OrElse pattern.IsNull) Then
                Return SqlBoolean.False
            End If
            Dim RegExOption As New System.Text.RegularExpressions.RegExOptions
            RegExOption = Options
            Return RegEx.IsMatch(input.Value, pattern.Value, RegExOption)
        End Function
    End Class      ' 
End Namespace

...and is installed in SQL Server using the following SQL (replacing '%'-delimted variables by their actual equivalents:

sp_configure 'clr enabled', 1
RECONFIGURE WITH OVERRIDE

IF EXISTS ( SELECT   1
            FROM     sys.objects
            WHERE    object_id = OBJECT_ID(N'dbo.RegExIsMatch') ) 
   DROP FUNCTION dbo.RegExIsMatch
go

IF EXISTS ( SELECT   1
            FROM     sys.assemblies asms
            WHERE    asms.name = N'RegExFunction ' ) 
   DROP ASSEMBLY [RegExFunction]

CREATE ASSEMBLY RegExFunction 
           FROM '%FILE%'
GO

CREATE FUNCTION RegExIsMatch
   (
    @Pattern NVARCHAR(4000),
    @Input NVARCHAR(MAX),
    @Options int
   )
RETURNS BIT
AS EXTERNAL NAME 
   RegExFunction.[SimpleTalk.Phil.Factor.RegularExpressionFunctions].RegExIsMatch
GO

--a few tests
---Is this card a valid credit card?
SELECT dbo.RegExIsMatch ('^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\d{3})\d{11})$','4241825283987487',1)
--is there a number in this string
SELECT dbo.RegExIsMatch( '\d','there is 1 thing I hate',1)
--Verifies number Returns 1
DECLARE @pattern VARCHAR(255)
SELECT @pattern ='[a-zA-Z0-9]\d{2}[a-zA-Z0-9](-\d{3}){2}[A-Za-z0-9]'
SELECT  dbo.RegExIsMatch (@pattern, '1298-673-4192',1),
        dbo.RegExIsMatch (@pattern,'A08Z-931-468A',1),
        dbo.RegExIsMatch (@pattern,'[A90-123-129X',1),
        dbo.RegExIsMatch (@pattern,'12345-KKA-1230',1),
        dbo.RegExIsMatch (@pattern,'0919-2893-1256',1)

Displaying Image in Java

Running your code shows an image for me, after adjusting the path. Can you verify that your image path is correct, try absolute path for instance?

right click context menu for datagridview

Use the CellMouseDown event on the DataGridView. From the event handler arguments you can determine which cell was clicked. Using the PointToClient() method on the DataGridView you can determine the relative position of the pointer to the DataGridView, so you can pop up the menu in the correct location.

(The DataGridViewCellMouseEvent parameter just gives you the X and Y relative to the cell you clicked, which isn't as easy to use to pop up the context menu.)

This is the code I used to get the mouse position, then adjust for the position of the DataGridView:

var relativeMousePosition = DataGridView1.PointToClient(Cursor.Position);
this.ContextMenuStrip1.Show(DataGridView1, relativeMousePosition);

The entire event handler looks like this:

private void DataGridView1_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
{
    // Ignore if a column or row header is clicked
    if (e.RowIndex != -1 && e.ColumnIndex != -1)
    {
        if (e.Button == MouseButtons.Right)
        {
            DataGridViewCell clickedCell = (sender as DataGridView).Rows[e.RowIndex].Cells[e.ColumnIndex];

            // Here you can do whatever you want with the cell
            this.DataGridView1.CurrentCell = clickedCell;  // Select the clicked cell, for instance

            // Get mouse position relative to the vehicles grid
            var relativeMousePosition = DataGridView1.PointToClient(Cursor.Position);

            // Show the context menu
            this.ContextMenuStrip1.Show(DataGridView1, relativeMousePosition);
        }
    }
}

how to convert `content://media/external/images/media/Y` to `file:///storage/sdcard0/Pictures/X.jpg` in android?

If you just want the bitmap, This too works

InputStream inputStream = mContext.getContentResolver().openInputStream(uri);
Bitmap bmp = BitmapFactory.decodeStream(inputStream);
if( inputStream != null ) inputStream.close();

sample uri : content://media/external/images/media/12345

Append key/value pair to hash with << in Ruby

There is merge!.

h = {}
h.merge!(key: "bar")
# => {:key=>"bar"}

How to put/get multiple JSONObjects to JSONArray?

Once you have put the values into the JSONObject then put the JSONObject into the JSONArray staright after.

Something like this maybe:

jsonObj.put("value1", 1);
jsonObj.put("value2", 900);
jsonObj.put("value3", 1368349);
jsonArray.put(jsonObj);

Then create new JSONObject, put the other values into it and add it to the JSONArray:

jsonObj.put("value1", 2);
jsonObj.put("value2", 1900);
jsonObj.put("value3", 136856);
jsonArray.put(jsonObj);

Adding open/closed icon to Twitter Bootstrap collapsibles (accordions)

The Bootstrap Collapse has some Events that you can react to:

$(document).ready(function(){    
    $('#accordProfile').on('shown', function () {
       $(".icon-chevron-down").removeClass("icon-chevron-down").addClass("icon-chevron-up");
    });

    $('#accordProfile').on('hidden', function () {
       $(".icon-chevron-up").removeClass("icon-chevron-up").addClass("icon-chevron-down");
    });
});

Deleting an object in C++

if it crashes on the delete line then you have almost certainly somehow corrupted the heap. We would need to see more code to diagnose the problem since the example you presented has no errors.

Perhaps you have a buffer overflow on the heap which corrupted the heap structures or even something as simple as a "double free" (or in the c++ case "double delete").

Also, as The Fuzz noted, you may have an error in your destructor as well.

And yes, it is completely normal and expected for delete to invoke the destructor, that is in fact one of its two purposes (call destructor then free memory).

Basic Ajax send/receive with node.js

RESTful API (Route):

rtr.route('/testing')
.get((req, res)=>{
    res.render('test')
})
.post((req, res, next)=>{
       res.render('test')
})

AJAX Code:

$(function(){
$('#anyid').on('click', function(e){
    e.preventDefault()
    $.ajax({
        url: '/testing',
        method: 'GET',
        contentType: 'application/json',
        success: function(res){
            console.log('GET Request')
        }
    })
})

$('#anyid').on('submit', function(e){
    e.preventDefault()
    $.ajax({
        url: '/testing',
        method: 'POST',
        contentType: 'application/json',
        data: JSON.stringify({
            info: "put data here to pass in JSON format."
        }),
        success: function(res){
            console.log('POST Request')
        }
    })
})
})

Session timeout in ASP.NET

I don't know about web.config or IIS. But I believe that from C# code you can do it like

Session.Timeout = 60; // 60 is number of minutes

How to represent a fix number of repeats in regular expression?

For Java:

Quantifiers documentation

X, exactly n times: X{n}
X, at least n times: X{n,}
X, at least n but not more than m times: X{n,m}

git pull from master into the development branch

The steps you listed will work, but there's a longer way that gives you more options:

git checkout dmgr2      # gets you "on branch dmgr2"
git fetch origin        # gets you up to date with origin
git merge origin/master

The fetch command can be done at any point before the merge, i.e., you can swap the order of the fetch and the checkout, because fetch just goes over to the named remote (origin) and says to it: "gimme everything you have that I don't", i.e., all commits on all branches. They get copied to your repository, but named origin/branch for any branch named branch on the remote.

At this point you can use any viewer (git log, gitk, etc) to see "what they have" that you don't, and vice versa. Sometimes this is only useful for Warm Fuzzy Feelings ("ah, yes, that is in fact what I want") and sometimes it is useful for changing strategies entirely ("whoa, I don't want THAT stuff yet").

Finally, the merge command takes the given commit, which you can name as origin/master, and does whatever it takes to bring in that commit and its ancestors, to whatever branch you are on when you run the merge. You can insert --no-ff or --ff-only to prevent a fast-forward, or merge only if the result is a fast-forward, if you like.

When you use the sequence:

git checkout dmgr2
git pull origin master

the pull command instructs git to run git fetch, and then the moral equivalent of git merge origin/master. So this is almost the same as doing the two steps by hand, but there are some subtle differences that probably are not too concerning to you. (In particular the fetch step run by pull brings over only origin/master, and it does not update the ref in your repo:1 any new commits winds up referred-to only by the special FETCH_HEAD reference.)

If you use the more-explicit git fetch origin (then optionally look around) and then git merge origin/master sequence, you can also bring your own local master up to date with the remote, with only one fetch run across the network:

git fetch origin
git checkout master
git merge --ff-only origin/master
git checkout dmgr2
git merge --no-ff origin/master

for instance.


1This second part has been changed—I say "fixed"—in git 1.8.4, which now updates "remote branch" references opportunistically. (It was, as the release notes say, a deliberate design decision to skip the update, but it turns out that more people prefer that git update it. If you want the old remote-branch SHA-1, it defaults to being saved in, and thus recoverable from, the reflog. This also enables a new git 1.9/2.0 feature for finding upstream rebases.)

Xcode/Simulator: How to run older iOS version?

To add previous iOS simulator to Xcode 4.2, you need old xcode_3.2.6_and_ios_sdk_4.3.dmg (or similar version) installer file and do as following:

  • Mount the xcode_3.2.6_and_ios_sdk_4.3.dmg file
  • Open mounting disk image and choose menu: Go->Go to Folder...
  • Type /Volumes/Xcode and iOS SDK/Packages/ then click Go. There are many packages and find to iPhoneSimulatorSDK(version).pkg
  • Double click to install package you want to add and wait for installer displays.
  • In Installer click Continue and choose destination, Choose folder...
  • Explorer shows and select Developer folder and click Choose
  • Install and repeat with other simulator as you need.
  • Restart Xcode.

Now there are a list of your installed simulator.

Counting lines, words, and characters within a text file using Python

Try this:

fname = "feed.txt"

num_lines = 0
num_words = 0
num_chars = 0

with open(fname, 'r') as f:
    for line in f:
        words = line.split()

        num_lines += 1
        num_words += len(words)
        num_chars += len(line)

Back to your code:

fname = "feed.txt"
fname = open('feed.txt', 'r')

what's the point of this? fname is a string first and then a file object. You don't really use the string defined in the first line and you should use one variable for one thing only: either a string or a file object.

for line in feed:
    lines = line.split('\n')

line is one line from the file. It does not make sense to split('\n') it.

Clearing UIWebview cache

For swift 2.0:

let cacheSizeMemory = 4*1024*1024; // 4MB
let cacheSizeDisk = 32*1024*1024; // 32MB
let sharedCache = NSURLCache(memoryCapacity: cacheSizeMemory, diskCapacity: cacheSizeDisk, diskPath: "nsurlcache")
NSURLCache.setSharedURLCache(sharedCache)

Html.Raw() in ASP.NET MVC Razor view

You shouldn't be calling .ToString().

As the error message clearly states, you're writing a conditional in which one half is an IHtmlString and the other half is a string.
That doesn't make sense, since the compiler doesn't know what type the entire expression should be.


There is never a reason to call Html.Raw(...).ToString().
Html.Raw returns an HtmlString instance that wraps the original string.
The Razor page output knows not to escape HtmlString instances.

However, calling HtmlString.ToString() just returns the original string value again; it doesn't accomplish anything.

Listen for key press in .NET console app

Addressing cases that some of the other answers don't handle well:

  • Responsive: direct execution of keypress handling code; avoids the vagaries of polling or blocking delays
  • Optionality: global keypress is opt-in; otherwise the app should exit normally
  • Separation of concerns: less invasive listening code; operates independently of normal console app code.

Many of the solutions on this page involve polling Console.KeyAvailable or blocking on Console.ReadKey. While it's true that the .NET Console is not very cooperative here, you can use Task.Run to move towards a more modern Async mode of listening.

The main issue to be aware of is that, by default, your console thread isn't set up for Async operation--meaning that, when you fall out of the bottom of your main function, instead of awaiting Async completions, your AppDoman and process will end. A proper way to address this would be to use Stephen Cleary's AsyncContext to establish full Async support in your single-threaded console program. But for simpler cases, like waiting for a keypress, installing a full trampoline may be overkill.

The example below would be for a console program used in some kind of iterative batch file. In this case, when the program is done with its work, normally it should exit without requiring a keypress, and then we allow an optional key press to prevent the app from exiting. We can pause the cycle to examine things, possibly resuming, or use the pause as a known 'control point' at which to cleanly break out of the batch file.

static void Main(String[] args)
{
    Console.WriteLine("Press any key to prevent exit...");
    var tHold = Task.Run(() => Console.ReadKey(true));

    // ... do your console app activity ...

    if (tHold.IsCompleted)
    {
#if false   // For the 'hold' state, you can simply halt forever...
        Console.WriteLine("Holding.");
        Thread.Sleep(Timeout.Infinite);
#else                            // ...or allow continuing to exit
        while (Console.KeyAvailable)
            Console.ReadKey(true);     // flush/consume any extras
        Console.WriteLine("Holding. Press 'Esc' to exit.");
        while (Console.ReadKey(true).Key != ConsoleKey.Escape)
            ;
#endif
    }
}

Multiline input form field using Bootstrap

The answer by Nick Mitchinson is for Bootstrap version 2.

If you are using Bootstrap version 3, then forms have changed a bit. For bootstrap 3, use the following instead:

<div class="form-horizontal">
    <div class="form-group">
        <div class="col-md-6">
            <textarea class="form-control" rows="3" placeholder="What's up?" required></textarea>
        </div>
    </div>
</div>

Where, col-md-6 will target medium sized devices. You can add col-xs-6 etc to target smaller devices.

rename the columns name after cbind the data

If you offer cbind a set of arguments all of whom are vectors, you will get not a dataframe, but rather a matrix, in this case an all character matrix. They have different features. You can get a dataframe if some of your arguments remain dataframes, Try:

merger <- cbind(Date =as.character(Date),
             weather1[ , c("High", "Low", "Avg..High", "Avg.Low")] , 
             ScnMov =sale$Scanned.Movement[a] )

Presenting modal in iOS 13 fullscreen

Change modalPresentationStyle before presenting

vc.modalPresentationStyle = UIModalPresentationFullScreen;

How do I download and save a file locally on iOS using objective C?

Sometime ago I implemented an easy to use "download manager" library: PTDownloadManager. You could give it a shot!

Add Class to Object on Page Load

This should work:

window.onload = function() {
  document.getElementById('about').className = 'expand';
};

Or if you're using jQuery:

$(function() {
  $('#about').addClass('expand');
});

Getting user input

sys.argv[0] is not the first argument but the filename of the python program you are currently executing. I think you want sys.argv[1]

Better way to sort array in descending order

You may specify a comparer(IComparer implementation) as a parameter in Array.Sort, the order of sorting actually depends on comparer. The default comparer is used in ascending sorting

Which command do I use to generate the build of a Vue app?

in your terminal

npm run build

and you host the dist folder. for more see this video

How to print Two-Dimensional Array like table

public class FormattedTablePrint {

    public static void printRow(int[] row) {
        for (int i : row) {
            System.out.print(i);
            System.out.print("\t");
        }
        System.out.println();
    }

    public static void main(String[] args) {
        int twoDm[][]= new int[7][5];
        int i,j,k=1;

        for(i=0;i<7;i++) {
            for(j=0;j<5;j++) {
                twoDm[i][j]=k;
                k++;
            }
        }

        for(int[] row : twoDm) {
            printRow(row);
        }
    }
}

Output

1   2   3   4   5   
6   7   8   9   10  
11  12  13  14  15  
16  17  18  19  20  
21  22  23  24  25  
26  27  28  29  30  
31  32  33  34  35  

Of course, you might swap the 7 & 5 as mentioned in other answers, to get 7 per row.

How can I show three columns per row?

This may be what you are looking for:

http://jsfiddle.net/L4L67/

_x000D_
_x000D_
body>div {_x000D_
  background: #aaa;_x000D_
  display: flex;_x000D_
  flex-wrap: wrap;_x000D_
}_x000D_
_x000D_
body>div>div {_x000D_
  flex-grow: 1;_x000D_
  width: 33%;_x000D_
  height: 100px;_x000D_
}_x000D_
_x000D_
body>div>div:nth-child(even) {_x000D_
  background: #23a;_x000D_
}_x000D_
_x000D_
body>div>div:nth-child(odd) {_x000D_
  background: #49b;_x000D_
}
_x000D_
<div>_x000D_
  <div></div>_x000D_
  <div></div>_x000D_
  <div></div>_x000D_
  <div></div>_x000D_
  <div></div>_x000D_
  <div></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

input type=file show only button

Ive a really hacky solution with this...

<style type="text/css"> 
    input[type="file"]
    { 
        width: 80px;        
    } 
</style>

<input id="File1" type="file" />

The problem is the width attribute that is hiding the text field will obvously vary between browsers, vary between Windows XP themes and so on. Maybe its something you can work with though?...

Binding Combobox Using Dictionary as the Datasource

I used Sorin Comanescu's solution, but hit a problem when trying to get the selected value. My combobox was a toolstrip combobox. I used the "combobox" property, which exposes a normal combobox.

I had a

 Dictionary<Control, string> controls = new Dictionary<Control, string>();

Binding code (Sorin Comanescu's solution - worked like a charm):

 controls.Add(pictureBox1, "Image");
 controls.Add(dgvText, "Text");
 cbFocusedControl.ComboBox.DataSource = new BindingSource(controls, null);
 cbFocusedControl.ComboBox.ValueMember = "Key";
 cbFocusedControl.ComboBox.DisplayMember = "Value";

The problem was that when I tried to get the selected value, I didn't realize how to retrieve it. After several attempts I got this:

 var control = ((KeyValuePair<Control, string>) cbFocusedControl.ComboBox.SelectedItem).Key

Hope it helps someone else!

How to call a PHP function on the click of a button

You can write like this in JavaScript or jQuery Ajax and call the file

_x000D_
_x000D_
$('#btn').click(function(){_x000D_
  $.ajax({_x000D_
    url:'test.php?call=true',_x000D_
    type:'GET',_x000D_
    success:function(data){_x000D_
    body.append(data);_x000D_
    }_x000D_
  });_x000D_
})
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.1/jquery.min.js"></script>_x000D_
<form  method='get' >_x000D_
_x000D_
  <input type="button" id="btn" value="click">_x000D_
</form>_x000D_
_x000D_
<?php_x000D_
    if(isset($_GET['call'])){_x000D_
_x000D_
        function anyfunction(){_x000D_
            echo "added";_x000D_
_x000D_
            // Your funtion code_x000D_
        }_x000D_
    }_x000D_
?>
_x000D_
_x000D_
_x000D_

string comparison in batch file

Just put quotes around the Environment variable (as you have done) :
if "%DevEnvDir%" == "C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\"
but it's the way you put opening bracket without a space that is confusing it.

Works for me...

C:\if "%gtk_basepath%" == "C:\Program Files\GtkSharp\2.12\" (echo yes)
yes

How to add anything in <head> through jquery/javascript?

In the latest browsers (IE9+) you can also use document.head:

Example:

var favicon = document.createElement('link');
favicon.id = 'myFavicon';
favicon.rel = 'shortcut icon';
favicon.href = 'http://www.test.com/my-favicon.ico';

document.head.appendChild(favicon);

How to loop through a HashMap in JSP?

Depending on what you want to accomplish within the loop, iterate over one of these instead:

  • countries.keySet()
  • countries.entrySet()
  • countries.values()

Apache Proxy: No protocol handler was valid

This can happen if you don't have mod_proxy_http enabled

sudo a2enmod proxy_http

For me to get my https based load balancer working, i had to enable the following:

sudo a2enmod ssl
sudo a2enmod proxy
sudo a2enmod proxy_balancer
sudo a2enmod proxy_http

Hiding user input on terminal in Linux script

Update

In case you want to get fancy by outputting an * for each character they type, you can do something like this (using andreas' read -s solution):

unset password;
while IFS= read -r -s -n1 pass; do
  if [[ -z $pass ]]; then
     echo
     break
  else
     echo -n '*'
     password+=$pass
  fi
done

Without being fancy

echo "Please enter your username";
read username;

echo "Please enter your password";
stty -echo
read password;
stty echo

Get current location of user in Android without using GPS or internet

It appears that it is possible to track a smart phone without using GPS.

Sources:

Primary: "PinMe: Tracking a Smartphone User around the World"

Secondary: "How to Track a Cellphone Without GPS—or Consent"

I have not yet found a link to the team's final code. When I do I will post, if another has not done so.

How to properly create composite primary keys - MYSQL

I would use a composite (multi-column) key.

CREATE TABLE INFO (
    t1ID INT,
    t2ID INT,
    PRIMARY KEY (t1ID, t2ID)
) 

This way you can have t1ID and t2ID as foreign keys pointing to their respective tables as well.

How to get ELMAH to work with ASP.NET MVC [HandleError] attribute?

You can subclass HandleErrorAttribute and override its OnException member (no need to copy) so that it logs the exception with ELMAH and only if the base implementation handles it. The minimal amount of code you need is as follows:

using System.Web.Mvc;
using Elmah;

public class HandleErrorAttribute : System.Web.Mvc.HandleErrorAttribute
{
    public override void OnException(ExceptionContext context)
    {
        base.OnException(context);
        if (!context.ExceptionHandled) 
            return;
        var httpContext = context.HttpContext.ApplicationInstance.Context;
        var signal = ErrorSignal.FromContext(httpContext);
        signal.Raise(context.Exception, httpContext);
    }
}

The base implementation is invoked first, giving it a chance to mark the exception as being handled. Only then is the exception signaled. The above code is simple and may cause issues if used in an environment where the HttpContext may not be available, such as testing. As a result, you will want code that is that is more defensive (at the cost of being slightly longer):

using System.Web;
using System.Web.Mvc;
using Elmah;

public class HandleErrorAttribute : System.Web.Mvc.HandleErrorAttribute
{
    public override void OnException(ExceptionContext context)
    {
        base.OnException(context);
        if (!context.ExceptionHandled       // if unhandled, will be logged anyhow
            || TryRaiseErrorSignal(context) // prefer signaling, if possible
            || IsFiltered(context))         // filtered?
            return;

        LogException(context);
    }

    private static bool TryRaiseErrorSignal(ExceptionContext context)
    {
        var httpContext = GetHttpContextImpl(context.HttpContext);
        if (httpContext == null)
            return false;
        var signal = ErrorSignal.FromContext(httpContext);
        if (signal == null)
            return false;
        signal.Raise(context.Exception, httpContext);
        return true;
    }

    private static bool IsFiltered(ExceptionContext context)
    {
        var config = context.HttpContext.GetSection("elmah/errorFilter")
                        as ErrorFilterConfiguration;

        if (config == null)
            return false;

        var testContext = new ErrorFilterModule.AssertionHelperContext(
                              context.Exception, 
                              GetHttpContextImpl(context.HttpContext));
        return config.Assertion.Test(testContext);
    }

    private static void LogException(ExceptionContext context)
    {
        var httpContext = GetHttpContextImpl(context.HttpContext);
        var error = new Error(context.Exception, httpContext);
        ErrorLog.GetDefault(httpContext).Log(error);
    }

    private static HttpContext GetHttpContextImpl(HttpContextBase context)
    {
        return context.ApplicationInstance.Context;
    }
}

This second version will try to use error signaling from ELMAH first, which involves the fully configured pipeline like logging, mailing, filtering and what have you. Failing that, it attempts to see whether the error should be filtered. If not, the error is simply logged. This implementation does not handle mail notifications. If the exception can be signaled then a mail will be sent if configured to do so.

You may also have to take care that if multiple HandleErrorAttribute instances are in effect then duplicate logging does not occur, but the above two examples should get your started.

configure: error: C compiler cannot create executables

I just had this issue building react-native app when I try to install Pod. I had to export 2 variables:

export CC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
CPP='/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc -E'

How do I `jsonify` a list in Flask?

If you are searching literally the way to return a JSON list in flask and you are completly sure that your variable is a list then the easy way is (where bin is a list of 1's and 0's):

   return jsonify({'ans':bin}), 201

Finally, in your client you will obtain something like

{ "ans": [ 0.0, 0.0, 1.0, 1.0, 0.0 ] }

VB.NET - If string contains "value1" or "value2"

You have to do it like this:

If strMyString.Contains("Something") OrElse strMyString.Contains("Something2") Then
    '[Put Code Here]
End if

Vba macro to copy row from table if value in table meets condition

Try it like this:

Sub testIt()
Dim r As Long, endRow as Long, pasteRowIndex As Long

endRow = 10 ' of course it's best to retrieve the last used row number via a function
pasteRowIndex = 1

For r = 1 To endRow 'Loop through sheet1 and search for your criteria

    If Cells(r, Columns("B").Column).Value = "YourCriteria" Then 'Found

            'Copy the current row
            Rows(r).Select 
            Selection.Copy

            'Switch to the sheet where you want to paste it & paste
            Sheets("Sheet2").Select
            Rows(pasteRowIndex).Select
            ActiveSheet.Paste

            'Next time you find a match, it will be pasted in a new row
            pasteRowIndex = pasteRowIndex + 1


           'Switch back to your table & continue to search for your criteria
            Sheets("Sheet1").Select  
    End If
Next r
End Sub

XAMPP keeps showing Dashboard/Welcome Page instead of the Configuration Page

I had the same problem. I uninstalled the 6.8.14 and installed back older version 5.6.8, and it worked.

Parsing JSON object in PHP using json_decode

Try this example

$json = '{"foo-bar": 12345}';

$obj = json_decode($json);
print $obj->{'foo-bar'}; // 12345

http://php.net/manual/en/function.json-decode.php

NB - two negatives makes a positive . :)

Why do we need middleware for async flow in Redux?

You don't.

But... you should use redux-saga :)

Dan Abramov's answer is right about redux-thunk but I will talk a bit more about redux-saga that is quite similar but more powerful.

Imperative VS declarative

  • DOM: jQuery is imperative / React is declarative
  • Monads: IO is imperative / Free is declarative
  • Redux effects: redux-thunk is imperative / redux-saga is declarative

When you have a thunk in your hands, like an IO monad or a promise, you can't easily know what it will do once you execute. The only way to test a thunk is to execute it, and mock the dispatcher (or the whole outside world if it interacts with more stuff...).

If you are using mocks, then you are not doing functional programming.

Seen through the lens of side-effects, mocks are a flag that your code is impure, and in the functional programmer's eye, proof that something is wrong. Instead of downloading a library to help us check the iceberg is intact, we should be sailing around it. A hardcore TDD/Java guy once asked me how you do mocking in Clojure. The answer is, we usually don't. We usually see it as a sign we need to refactor our code.

Source

The sagas (as they got implemented in redux-saga) are declarative and like the Free monad or React components, they are much easier to test without any mock.

See also this article:

in modern FP, we shouldn’t write programs — we should write descriptions of programs, which we can then introspect, transform, and interpret at will.

(Actually, Redux-saga is like a hybrid: the flow is imperative but the effects are declarative)

Confusion: actions/events/commands...

There is a lot of confusion in the frontend world on how some backend concepts like CQRS / EventSourcing and Flux / Redux may be related, mostly because in Flux we use the term "action" which can sometimes represent both imperative code (LOAD_USER) and events (USER_LOADED). I believe that like event-sourcing, you should only dispatch events.

Using sagas in practice

Imagine an app with a link to a user profile. The idiomatic way to handle this with each middleware would be:

redux-thunk

<div onClick={e => dispatch(actions.loadUserProfile(123)}>Robert</div>

function loadUserProfile(userId) {
  return dispatch => fetch(`http://data.com/${userId}`)
    .then(res => res.json())
    .then(
      data => dispatch({ type: 'USER_PROFILE_LOADED', data }),
      err => dispatch({ type: 'USER_PROFILE_LOAD_FAILED', err })
    );
}

redux-saga

<div onClick={e => dispatch({ type: 'USER_NAME_CLICKED', payload: 123 })}>Robert</div>


function* loadUserProfileOnNameClick() {
  yield* takeLatest("USER_NAME_CLICKED", fetchUser);
}

function* fetchUser(action) {
  try {
    const userProfile = yield fetch(`http://data.com/${action.payload.userId }`)
    yield put({ type: 'USER_PROFILE_LOADED', userProfile })
  } 
  catch(err) {
    yield put({ type: 'USER_PROFILE_LOAD_FAILED', err })
  }
}

This saga translates to:

every time a username gets clicked, fetch the user profile and then dispatch an event with the loaded profile.

As you can see, there are some advantages of redux-saga.

The usage of takeLatest permits to express that you are only interested to get the data of the last username clicked (handle concurrency problems in case the user click very fast on a lot of usernames). This kind of stuff is hard with thunks. You could have used takeEvery if you don't want this behavior.

You keep action creators pure. Note it's still useful to keep actionCreators (in sagas put and components dispatch), as it might help you to add action validation (assertions/flow/typescript) in the future.

Your code becomes much more testable as the effects are declarative

You don't need anymore to trigger rpc-like calls like actions.loadUser(). Your UI just needs to dispatch what HAS HAPPENED. We only fire events (always in the past tense!) and not actions anymore. This means that you can create decoupled "ducks" or Bounded Contexts and that the saga can act as the coupling point between these modular components.

This means that your views are more easy to manage because they don't need anymore to contain that translation layer between what has happened and what should happen as an effect

For example imagine an infinite scroll view. CONTAINER_SCROLLED can lead to NEXT_PAGE_LOADED, but is it really the responsibility of the scrollable container to decide whether or not we should load another page? Then he has to be aware of more complicated stuff like whether or not the last page was loaded successfully or if there is already a page that tries to load, or if there is no more items left to load? I don't think so: for maximum reusability the scrollable container should just describe that it has been scrolled. The loading of a page is a "business effect" of that scroll

Some might argue that generators can inherently hide state outside of redux store with local variables, but if you start to orchestrate complex things inside thunks by starting timers etc you would have the same problem anyway. And there's a select effect that now permits to get some state from your Redux store.

Sagas can be time-traveled and also enables complex flow logging and dev-tools that are currently being worked on. Here is some simple async flow logging that is already implemented:

saga flow logging

Decoupling

Sagas are not only replacing redux thunks. They come from backend / distributed systems / event-sourcing.

It is a very common misconception that sagas are just here to replace your redux thunks with better testability. Actually this is just an implementation detail of redux-saga. Using declarative effects is better than thunks for testability, but the saga pattern can be implemented on top of imperative or declarative code.

In the first place, the saga is a piece of software that permits to coordinate long running transactions (eventual consistency), and transactions across different bounded contexts (domain driven design jargon).

To simplify this for frontend world, imagine there is widget1 and widget2. When some button on widget1 is clicked, then it should have an effect on widget2. Instead of coupling the 2 widgets together (ie widget1 dispatch an action that targets widget2), widget1 only dispatch that its button was clicked. Then the saga listen for this button click and then update widget2 by dispaching a new event that widget2 is aware of.

This adds a level of indirection that is unnecessary for simple apps, but make it more easy to scale complex applications. You can now publish widget1 and widget2 to different npm repositories so that they never have to know about each others, without having them to share a global registry of actions. The 2 widgets are now bounded contexts that can live separately. They do not need each others to be consistent and can be reused in other apps as well. The saga is the coupling point between the two widgets that coordinate them in a meaningful way for your business.

Some nice articles on how to structure your Redux app, on which you can use Redux-saga for decoupling reasons:

A concrete usecase: notification system

I want my components to be able to trigger the display of in-app notifications. But I don't want my components to be highly coupled to the notification system that has its own business rules (max 3 notifications displayed at the same time, notification queueing, 4 seconds display-time etc...).

I don't want my JSX components to decide when a notification will show/hide. I just give it the ability to request a notification, and leave the complex rules inside the saga. This kind of stuff is quite hard to implement with thunks or promises.

notifications

I've described here how this can be done with saga

Why is it called a Saga?

The term saga comes from the backend world. I initially introduced Yassine (the author of Redux-saga) to that term in a long discussion.

Initially, that term was introduced with a paper, the saga pattern was supposed to be used to handle eventual consistency in distributed transactions, but its usage has been extended to a broader definition by backend developers so that it now also covers the "process manager" pattern (somehow the original saga pattern is a specialized form of process manager).

Today, the term "saga" is confusing as it can describe 2 different things. As it is used in redux-saga, it does not describe a way to handle distributed transactions but rather a way to coordinate actions in your app. redux-saga could also have been called redux-process-manager.

See also:

Alternatives

If you don't like the idea of using generators but you are interested by the saga pattern and its decoupling properties, you can also achieve the same with redux-observable which uses the name epic to describe the exact same pattern, but with RxJS. If you're already familiar with Rx, you'll feel right at home.

const loadUserProfileOnNameClickEpic = action$ =>
  action$.ofType('USER_NAME_CLICKED')
    .switchMap(action =>
      Observable.ajax(`http://data.com/${action.payload.userId}`)
        .map(userProfile => ({
          type: 'USER_PROFILE_LOADED',
          userProfile
        }))
        .catch(err => Observable.of({
          type: 'USER_PROFILE_LOAD_FAILED',
          err
        }))
    );

Some redux-saga useful resources

2017 advises

  • Don't overuse Redux-saga just for the sake of using it. Testable API calls only are not worth it.
  • Don't remove thunks from your project for most simple cases.
  • Don't hesitate to dispatch thunks in yield put(someActionThunk) if it makes sense.

If you are frightened of using Redux-saga (or Redux-observable) but just need the decoupling pattern, check redux-dispatch-subscribe: it permits to listen to dispatches and trigger new dispatches in listener.

const unsubscribe = store.addDispatchListener(action => {
  if (action.type === 'ping') {
    store.dispatch({ type: 'pong' });
  }
});

How to SHUTDOWN Tomcat in Ubuntu?

I had a similar problem and found the following command to work:

sudo systemctl stop tomcat

After running this command you can type the following to verify that it is "disabled":

systemctl list-units

output for systemctl list-units

T-SQL: Using a CASE in an UPDATE statement to update certain columns depending on a condition

I know this is a very old question, but this worked for me:

UPDATE TABLE SET FIELD1 =
CASE 
WHEN FIELD1 = Condition1 THEN 'Result1'
WHEN FIELD1 = Condition2 THEN 'Result2'
WHEN FIELD1 = Condition3 THEN 'Result3'
END;

Regards

How do I embed a mp4 movie into my html?

If you have an mp4 video residing at your server, and you want the visitors to stream that over your HTML page.

<video width="480" height="320" controls="controls">
<source src="http://serverIP_or_domain/location_of_video.mp4" type="video/mp4">
</video>

Laravel 5.4 Specific Table Migration

install this package

https://github.com/nilpahar/custom-migration/

and run this command.

php artisan migrate:custom -f migration_name

Javascript Equivalent to C# LINQ Select

Since you're using knockout, you should consider using the knockout utility function arrayMap() and it's other array utility functions.

Here's a listing of array utility functions and their equivalent LINQ methods:

arrayFilter() -> Where()
arrayFirst() -> First()
arrayForEach() -> (no direct equivalent)
arrayGetDistictValues() -> Distinct()
arrayIndexOf() -> IndexOf()
arrayMap() -> Select()
arrayPushAll() -> (no direct equivalent)
arrayRemoveItem() -> (no direct equivalent)
compareArrays() -> (no direct equivalent)

So what you could do in your example is this:

var mapped = ko.utils.arrayMap(selectedFruits, function (fruit) {
    return fruit.id;
});

If you want a LINQ like interface in javascript, you could use a library such as linq.js which offers a nice interface to many of the LINQ methods.

var mapped = Enumerable.From(selectedFruits)
    .Select("$.id") // 1 of 3 different ways to specify a selector function
    .ToArray();

Script Tag - async & defer

Async is suitable if your script doesn’t contains DOM manipulation and other scripts doesn’t depend upon on this. Eg: bootstrap cdn,jquery

Defer is suitable if your script contains DOM manipulation and other scripts depend upon on this.

Eg: <script src=”createfirst.js”> //let this will create element <script src=”showfirst.js”> //after createfirst create element it will show that.

Thus make it: Eg: <script defer src=”createfirst.js”> //let this will create element <script defer src=”showfirst.js”> //after createfirst create element it will

This will execute scripts in order.

But if i made: Eg: <script async src=”createfirst.js”> //let this will create element <script defer src=”showfirst.js”> //after createfirst create element it will

Then, this code might result unexpected results. Coz: if html parser access createfirst script.It won’t stop DOM creation and starts downloading code from src .Once src got resolved/code got downloaded, it will execute immediately parallel with DOM.

What if showfirst.js execute first than createfirst.js.This might be possible if createfirst takes long time (Assume after DOM parsing finished).Then, showfirst will execute immediately.

How to configure SSL certificates with Charles Web Proxy and the latest Android Emulator on Windows?

In Charles, go to Proxy>>Proxy Settings and select the SSL tab. Add your host to the list of Locations.

For example, if your secure call is going to https://secure.example.com, you can enter secure.example.com, or *.example.com.

Once the above is in place, you may need to right-click on the call in the main Charles window and select the SSL Proxying option.

Hope this helps.

Shell equality operators (=, ==, -eq)

Several answers show dangerous examples. OP's example [ $a == $b ] specifically used unquoted variable substitution (as of Oct '17 edit). For [...] that is safe for string equality.

But if you're going to enumerate alternatives like [[...]], you must inform also that the right-hand-side must be quoted. If not quoted, it is a pattern match! (From bash man page: "Any part of the pattern may be quoted to force it to be matched as a string.").

Here in bash, the two statements yielding "yes" are pattern matching, other three are string equality:

$ rht="A*"
$ lft="AB"
$ [ $lft = $rht ] && echo yes
$ [ $lft == $rht ] && echo yes
$ [[ $lft = $rht ]] && echo yes
yes
$ [[ $lft == $rht ]] && echo yes
yes
$ [[ $lft == "$rht" ]] && echo yes
$

creating array without declaring the size - java

You might be looking for a List? Either LinkedList or ArrayList are good classes to take a look at. You can then call toArray() to get the list as an array.

Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

For Jar

Add pom.xml

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

How to subtract hours from a date in Oracle so it affects the day also

Try this:

SELECT to_char(sysdate - (2 / 24), 'MM-DD-YYYY HH24') FROM DUAL

To test it using a new date instance:

SELECT to_char(TO_DATE('11/06/2015 00:00','dd/mm/yyyy HH24:MI') - (2 / 24), 'MM-DD-YYYY HH24:MI') FROM DUAL

Output is: 06-10-2015 22:00, which is the previous day.

Docker CE on RHEL - Requires: container-selinux >= 2.9

I followed many links including the official documentation, however it all ended up in this error:

Requires: container-selinux >= 2.9
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest

The only way it worked for me is as follows (yum upgrade worked I guess):

yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

yum upgrade docker-ce

LINQ: "contains" and a Lambda query

Here is how you can use Contains to achieve what you want:

buildingStatus.Select(item => item.GetCharValue()).Contains(v.Status) this will return a Boolean value.

PowerShell Connect to FTP server and get files

Based on Why does FtpWebRequest download files from the root directory? Can this cause a 553 error?, I wrote a PowerShell script that enabled to download a file from a FTP-Server via explicit FTP over TLS:

# Config
$Username = "USERNAME"
$Password = "PASSWORD"
$LocalFile = "C:\PATH_TO_DIR\FILNAME.EXT"
#e.g. "C:\temp\somefile.txt"
$RemoteFile = "ftp://PATH_TO_REMOTE_FILE"
#e.g. "ftp://ftp.server.com/home/some/path/somefile.txt"

try{ 
    # Create a FTPWebRequest
    $FTPRequest = [System.Net.FtpWebRequest]::Create($RemoteFile)
    $FTPRequest.Credentials = New-Object System.Net.NetworkCredential($Username,$Password)
    $FTPRequest.Method = [System.Net.WebRequestMethods+Ftp]::DownloadFile
    $FTPRequest.UseBinary = $true
    $FTPRequest.KeepAlive = $false
    $FTPRequest.EnableSsl  = $true
    # Send the ftp request
    $FTPResponse = $FTPRequest.GetResponse()
    # Get a download stream from the server response
    $ResponseStream = $FTPResponse.GetResponseStream()
    # Create the target file on the local system and the download buffer
    $LocalFileFile = New-Object IO.FileStream ($LocalFile,[IO.FileMode]::Create)
    [byte[]]$ReadBuffer = New-Object byte[] 1024
    # Loop through the download

    do {
        $ReadLength = $ResponseStream.Read($ReadBuffer,0,1024)
        $LocalFileFile.Write($ReadBuffer,0,$ReadLength)
    }
    while ($ReadLength -ne 0)
}catch [Exception]
{
    $Request = $_.Exception
    Write-host "Exception caught: $Request"
}

Does java have a int.tryparse that doesn't throw an exception for bad data?

Edit -- just saw your comment about the performance problems associated with a potentially bad piece of input data. I don't know offhand how try/catch on parseInt compares to a regex. I would guess, based on very little hard knowledge, that regexes are not hugely performant, compared to try/catch, in Java.

Anyway, I'd just do this:

public Integer tryParse(Object obj) {
  Integer retVal;
  try {
    retVal = Integer.parseInt((String) obj);
  } catch (NumberFormatException nfe) {
    retVal = 0; // or null if that is your preference
  }
  return retVal;
}

How can I check whether an array is null / empty?

I am from .net background. However, java/c# are more/less same.

If you instantiate a non-primitive type (array in your case), it won't be null.
e.g. int[] numbers = new int[3];
In this case, the space is allocated & each of the element has a default value of 0.

It will be null, when you don't new it up.
e.g.

int[] numbers = null; // changed as per @Joachim's suggestion.
if (numbers == null)
{
   System.out.println("yes, it is null. Please new it up");
}

Android Crop Center of Bitmap

You can used following code that can solve your problem.

Matrix matrix = new Matrix();
matrix.postScale(0.5f, 0.5f);
Bitmap croppedBitmap = Bitmap.createBitmap(bitmapOriginal, 100, 100,100, 100, matrix, true);

Above method do postScalling of image before cropping, so you can get best result with cropped image without getting OOM error.

For more detail you can refer this blog

How to convert float to int with Java

Use Math.round(value) then after type cast it to integer.

float a = 8.61f;
int b = (int)Math.round(a);

How to search a list of tuples in Python

[i for i, v in enumerate(L) if v[0] == 53]

ASP MVC href to a controller/view

There are a couple of ways that you can accomplish this. You can do the following:

<li>
     @Html.ActionLink("Clients", "Index", "User", new { @class = "elements" }, null)
</li>

or this:

<li>
     <a href="@Url.Action("Index", "Users")" class="elements">
          <span>Clients</span>
     </a>
</li>

Lately I do the following:

<a href="@Url.Action("Index", null, new { area = string.Empty, controller = "User" }, Request.Url.Scheme)">
     <span>Clients</span>
</a>

The result would have http://localhost/10000 (or with whatever port you are using) to be appended to the URL structure like:

http://localhost:10000/Users

I hope this helps.

Eclipse count lines of code

There's always the "brute force":

  1. Search->File

  2. Type the following in "Containing text" -> ^.*$. Then check the "Regular Expression" checkbox

  3. Type the following in "File name patterns" -> *.java

  4. Click "Search"

  5. Check the number of matches in the "Search" Tab.

How to setup FTP on xampp

I launched ubuntu Xampp server on AWS amazon. And met the same problem with FTP, even though add user to group ftp SFTP and set permissions, owner group of htdocs folder. Finally find the reason in inbound rules in security group, added All TCP, 0 - 65535 rule(0.0.0.0/0,::/0) , then working right!

Error - replacement has [x] rows, data has [y]

You could use cut

 df$valueBin <- cut(df$value, c(-Inf, 250, 500, 1000, 2000, Inf), 
    labels=c('<=250', '250-500', '500-1,000', '1,000-2,000', '>2,000'))

data

 set.seed(24)
 df <- data.frame(value= sample(0:2500, 100, replace=TRUE))

How to delete all records from table in sqlite with Android?

Can be usefull.

public boolean deleteAllFood() {
            SQLiteDatabase db = dbHelper.getReadableDatabase();
            int affectedRows = db.delete(DBHelper.TABLE_NAME_FOOD, null, null);
            return affectedRows > 0;
        }



public class DBProgram {
    private static DBProgram INSTANCE;
    private Context context;
    private DBHelper dbHelper;

    private DBProgram(Context context) {
        // burda bu methodu kullanan activity ile eilestiriyoruz
        this.dbHelper = new DBHelper(context);
    }

    public static synchronized DBProgram getInstance(Context context) {
        if (INSTANCE == null) {
            INSTANCE = new DBProgram(context);
        }
        return INSTANCE;
    }

    //**********************************************
    public boolean updateById(ProgramModel program) {
        SQLiteDatabase database = dbHelper.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(DBHelper.COLUM_NAME_P, program.getProgName());
        contentValues.put(DBHelper.COLUM_DAY_P, program.getDay());
        contentValues.put(DBHelper.COLUMN_WEIGHT_P, program.getWeight());
        contentValues.put(DBHelper.COLUMN_SET_P, program.getSet());
        contentValues.put(DBHelper.COLUMN_REPETITION_P, program.getRepetition());
        int affectedRows = database.update(DBHelper.TABLE_NAME_PROGRAM, contentValues, "PROG_ID_P = ?", new String[]{String.valueOf(program.getId())});
        return affectedRows > 0;
    }
    //**********************************************


    //**********************************************
    // TODO
    public boolean deleteProgramById(int id) {
        SQLiteDatabase database = dbHelper.getReadableDatabase();
        int affectedRows = database.delete(DBHelper.TABLE_NAME_PROGRAM, DBHelper.COLUMN_ID_P + "= ?", new String[]{String.valueOf(id)});
        // return bize etkilenen sira sayisiniini temsil eder
        return affectedRows > 0;
    }
    //**********************************************


    //***************************************************
    public boolean deleteProgramByName(String progName) {
        SQLiteDatabase database = dbHelper.getReadableDatabase();
        final String whereClause = DBHelper.COLUM_NAME_P + "=?";
        final String whereArgs[] = {progName};
        int affectedRows = database.delete(DBHelper.TABLE_NAME_PROGRAM, whereClause, whereArgs);
        return affectedRows > 0;
    }
    //***************************************************


    //************************************** get Meal
    // TODO  WEB Get All  Meals
    public List<ProgramModel> getAllProgram(String name) {
        List<ProgramModel> foodList = new ArrayList<>();
        ProgramModel food;
        SQLiteDatabase database = dbHelper.getReadableDatabase();
        final String kolonlar[] = {DBHelper.COLUMN_ID_P,
                DBHelper.COLUM_NAME_P,
                DBHelper.COLUM_DAY_P,
                DBHelper.COLUMN_WEIGHT_P,
                DBHelper.COLUMN_SET_P,
                DBHelper.COLUMN_REPETITION_P};

        final String whereClause = DBHelper.COLUM_DAY_P + "=?";
        final String whereArgs[] = {name};
        Cursor cursor = database.query(DBHelper.TABLE_NAME_PROGRAM, kolonlar, whereClause, whereArgs, null, null, null);
        while (cursor.moveToNext()) {

            food = new ProgramModel();
            food.setId(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_ID_P)));
            food.setProgName(cursor.getString(cursor.getColumnIndex(DBHelper.COLUM_NAME_P)));
            food.setDay(cursor.getString(cursor.getColumnIndex(DBHelper.COLUM_DAY_P)));
            food.setWeight(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_WEIGHT_P)));
            food.setSet(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_SET_P)));
            food.setRepetition(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_REPETITION_P)));
            foodList.add(food);
        }
        database.close();
        cursor.close();
        return foodList;
    }
    //**************************************


    //**************************************insert FOOD
    //TODO LOCAL insert Foods
    public boolean insertProgram(ProgramModel favorite) {
        boolean result = false;
        ContentValues contentValues = new ContentValues();
        contentValues.put(DBHelper.COLUM_NAME_P, favorite.getProgName());
        contentValues.put(DBHelper.COLUM_DAY_P, favorite.getDay());
        contentValues.put(DBHelper.COLUMN_WEIGHT_P, favorite.getWeight());
        contentValues.put(DBHelper.COLUMN_SET_P, favorite.getSet());
        contentValues.put(DBHelper.COLUMN_REPETITION_P, favorite.getRepetition());
        SQLiteDatabase database = dbHelper.getWritableDatabase();
        long id = database.insert(DBHelper.TABLE_NAME_PROGRAM, null, contentValues);
        if (id != 1) {
            result = true;
        }
        database.close();

        return result;
    }
    //***************************************************

    // *******************************  SQLITE HELPER CLASS ******************
    private class DBHelper extends SQLiteOpenHelper {
        private final Context context;
        private static final String DATABASE_NAME = "PROGRAM_INFO";
        private static final String TABLE_NAME_PROGRAM = "PROGRAM";
        private static final int DATABASE_VERSION = 2;

        // FOOD
        private static final String COLUMN_ID_P = "PROG_ID_P";
        private static final String COLUM_NAME_P = "PROG_NAME_P";
        private static final String COLUM_DAY_P = "PROG_DAY_P";
        private static final String COLUMN_WEIGHT_P = "PROG_WEIGHT_P";
        private static final String COLUMN_SET_P = "PROG_SET_P";
        private static final String COLUMN_REPETITION_P = "PROG_REPETITION_P";

        private final String CREATE_TABLE_PROGRAM = "CREATE TABLE " + TABLE_NAME_PROGRAM +
                " (" + COLUMN_ID_P + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + COLUM_NAME_P + " TEXT, "
                + COLUM_DAY_P + " TEXT, "
                + COLUMN_WEIGHT_P + " INTEGER, "
                + COLUMN_SET_P + " INTEGER, "
                + COLUMN_REPETITION_P + " INTEGER)";

        private static final String DROP_TABLE_PROGRAM = "DROP TABLE IF EXIST " + TABLE_NAME_PROGRAM;

        public DBHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            this.context = context;
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(CREATE_TABLE_PROGRAM);

            Util.showMessage(context, "Database Created");
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            db.execSQL(DROP_TABLE_PROGRAM);
            Util.showMessage(context, "Database Upgrated");
            onCreate(db);
        }

        @Override
        public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            super.onDowngrade(db, oldVersion, newVersion);
        }
    }


}

org.json.simple cannot be resolved

I was facing same issue in my Spring Integration project. I added below JSON dependencies in pom.xml file. It works for me.

<dependency>
  <groupId>org.json</groupId>
  <artifactId>json</artifactId>
  <version>20090211</version>
</dependency>

A list of versions can be found here: https://mvnrepository.com/artifact/org.json/json

ORA-01843 not a valid month- Comparing Dates

In a comment to one of the answers you mention that to_date with a format doesn't help. In another comment you explain that the table is accessed via DBLINK.

So obviously the other system contains an invalid date that Oracle cannot accept. Fix this in the other dbms (or whatever you dblink to) and your query will work.

Having said this, I agree with the others: always use to_date with a format to convert a string literal to a date. Also never use only two digits for a year. For example '23/04/49' means 2049 in your system (format RR), but it confuses the reader (as you see from the answers suggesting a format with YY).

How to loop through an array of objects in swift

The photos property is an optional array and must be unwrapped before accessing its elements (the same as you do to get the count property of the array):

for var i = 0; i < userPhotos!.count ; ++i {
    let url = userPhotos![i].url
}

Insert 2 million rows into SQL Server quickly

I use the bcp utility. (Bulk Copy Program) I load about 1.5 million text records each month. Each text record is 800 characters wide. On my server, it takes about 30 seconds to add the 1.5 million text records into a SQL Server table.

The instructions for bcp are at http://msdn.microsoft.com/en-us/library/ms162802.aspx

How to set a CheckBox by default Checked in ASP.Net MVC

My way is @Html.CheckBoxFor(model => model.As, new { @value= "true" }) (meaning is checked)

Error after upgrading pip: cannot import name 'main'

Check if pip has been cached on another path, to do so, call $ which pip and check that the path is different from the one prompted in the error, if that's the case run:

$ hash -r

When the cache is clear, pip will be working again. reference: http://cheng.logdown.com/posts/2015/06/14/-usr-bin-pip-no-such-file-or-directory

Maven not found in Mac OSX mavericks

brew install maven

Please ensure that you've installed the latest Xcode and Command Line tools.

xcode-select --install