Programs & Examples On #U2

U2 refers to the family of products that revolve around two MultiValue Databases called UniData and UniVerse. U2 includes connectivity tools, development tools and a 4GL development environment.

Search input with an icon Bootstrap 4

I made another variant with dropdown menu (perhaps for advanced search etc).. Here is how it looks like:

Bootstrap 4 searh bar with dropdown menu

<div class="input-group my-4 col-6 mx-auto">
    <input class="form-control py-2 border-right-0 border" type="search" placeholder="Type something..." id="example-search-input">
    <span class="input-group-append">
        <button type="button" class="btn btn-outline-primary dropdown-toggle dropdown-toggle-split border border-left-0 border-right-0 rounded-0" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
            <span class="sr-only">Toggle Dropdown</span>
        </button>
        <button class="btn btn-outline-primary rounded-right" type="button">
            <i class="fas fa-search"></i>
        </button>
        <div class="dropdown-menu dropdown-menu-right">
            <a class="dropdown-item" href="#">Action</a>
            <a class="dropdown-item" href="#">Another action</a>
            <a class="dropdown-item" href="#">Something else here</a>
            <div role="separator" class="dropdown-divider"></div>
            <a class="dropdown-item" href="#">Separated link</a>
        </div>
    </span>
</div>

Note: It appears green in the screenshot because my site main theme is green.

Multiple conditions in ngClass - Angular 4

I hope this is one of the basic conditional classes

Solution: 1

<section [ngClass]="(condition)? 'class1 class2 ... classN' : 'another class1 ... classN' ">

Solution 2

<section [ngClass]="(condition)? 'class1 class2 ... classN' : '(condition)? 'class1 class2 ... classN':'another class' ">

Solution 3

<section [ngClass]="'myclass': condition, 'className2': condition2">

Bootstrap 4: Multilevel Dropdown Inside Navigation

I found this multidrop-down menu which work great in all device.

Also, have hover style

It supports multi-level submenus with bootstrap 4.

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_x000D_
$( document ).ready( function () {_x000D_
    $( '.navbar a.dropdown-toggle' ).on( 'click', function ( e ) {_x000D_
        var $el = $( this );_x000D_
        var $parent = $( this ).offsetParent( ".dropdown-menu" );_x000D_
        $( this ).parent( "li" ).toggleClass( 'show' );_x000D_
_x000D_
        if ( !$parent.parent().hasClass( 'navbar-nav' ) ) {_x000D_
            $el.next().css( { "top": $el[0].offsetTop, "left": $parent.outerWidth() - 4 } );_x000D_
        }_x000D_
        $( '.navbar-nav li.show' ).not( $( this ).parents( "li" ) ).removeClass( "show" );_x000D_
        return false;_x000D_
    } );_x000D_
} );
_x000D_
.navbar-light .navbar-nav .nav-link {_x000D_
    color: rgb(64, 64, 64);_x000D_
}_x000D_
.btco-menu li > a {_x000D_
    padding: 10px 15px;_x000D_
    color: #000;_x000D_
}_x000D_
_x000D_
.btco-menu .active a:focus,_x000D_
.btco-menu li a:focus ,_x000D_
.navbar > .show > a:focus{_x000D_
    background: transparent;_x000D_
    outline: 0;_x000D_
}_x000D_
_x000D_
.dropdown-menu .show > .dropdown-toggle::after{_x000D_
    transform: rotate(-90deg);_x000D_
}
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">_x000D_
_x000D_
<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>_x000D_
_x000D_
<nav class="navbar navbar-toggleable-md navbar-light bg-faded btco-menu">_x000D_
    <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">_x000D_
        <span class="navbar-toggler-icon"></span>_x000D_
    </button>_x000D_
    <a class="navbar-brand" href="#">Navbar</a>_x000D_
    <div class="collapse navbar-collapse" id="navbarNavDropdown">_x000D_
        <ul class="navbar-nav">_x000D_
            <li class="nav-item active">_x000D_
                <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>_x000D_
            </li>_x000D_
            <li class="nav-item">_x000D_
                <a class="nav-link" href="#">Features</a>_x000D_
            </li>_x000D_
            <li class="nav-item">_x000D_
                <a class="nav-link" href="#">Pricing</a>_x000D_
            </li>_x000D_
            <li class="nav-item dropdown">_x000D_
                <a class="nav-link dropdown-toggle" href="https://bootstrapthemes.co" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown link</a>_x000D_
                <ul class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">_x000D_
                    <li><a class="dropdown-item" href="#">Action</a></li>_x000D_
                    <li><a class="dropdown-item" href="#">Another action</a></li>_x000D_
                    <li><a class="dropdown-item dropdown-toggle" href="#">Submenu</a>_x000D_
                        <ul class="dropdown-menu">_x000D_
                            <li><a class="dropdown-item" href="#">Submenu action</a></li>_x000D_
                            <li><a class="dropdown-item" href="#">Another submenu action</a></li>_x000D_
_x000D_
                            <li><a class="dropdown-item dropdown-toggle" href="#">Subsubmenu</a>_x000D_
                                <ul class="dropdown-menu">_x000D_
                                    <li><a class="dropdown-item" href="#">Subsubmenu action</a></li>_x000D_
                                    <li><a class="dropdown-item" href="#">Another subsubmenu action</a></li>_x000D_
                                </ul>_x000D_
                            </li>_x000D_
                            <li><a class="dropdown-item dropdown-toggle" href="#">Second subsubmenu</a>_x000D_
                                <ul class="dropdown-menu">_x000D_
                                    <li><a class="dropdown-item" href="#">Subsubmenu action</a></li>_x000D_
                                    <li><a class="dropdown-item" href="#">Another subsubmenu action</a></li>_x000D_
                                </ul>_x000D_
                            </li>_x000D_
                        </ul>_x000D_
                    </li>_x000D_
                </ul>_x000D_
            </li>_x000D_
        </ul>_x000D_
    </div>_x000D_
</nav>
_x000D_
_x000D_
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Align button to the right

try to put your script and link on the head like this:

<html>
  <head>
     <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">
     <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"> 
     </script>
  </head>
  <body>
     <div class="row">
        <h3 class="one">Text</h3>
        <button class="btn btn-secondary pull-right">Button</button>
     </div>
  </body>
</html>

`col-xs-*` not working in Bootstrap 4

If you want to apply an extra small class in Bootstrap 4,you need to use col-. important thing to know is that col-xs- is dropped in Bootstrap4

How to use requirements.txt to install all dependencies in a python project

pip install -r requirements.txt for python 2.x

pip3 install -r requirements.txt for python 3.x (in case multiple versions are installed)

Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?

Even without looking at assembly, the most obvious reason is that /= 2 is probably optimized as >>=1 and many processors have a very quick shift operation. But even if a processor doesn't have a shift operation, the integer division is faster than floating point division.

Edit: your milage may vary on the "integer division is faster than floating point division" statement above. The comments below reveal that the modern processors have prioritized optimizing fp division over integer division. So if someone were looking for the most likely reason for the speedup which this thread's question asks about, then compiler optimizing /=2 as >>=1 would be the best 1st place to look.


On an unrelated note, if n is odd, the expression n*3+1 will always be even. So there is no need to check. You can change that branch to

{
   n = (n*3+1) >> 1;
   count += 2;
}

So the whole statement would then be

if (n & 1)
{
    n = (n*3 + 1) >> 1;
    count += 2;
}
else
{
    n >>= 1;
    ++count;
}

http post - how to send Authorization header?

I had the same issue. This is my solution using angular documentation and firebase Token:

getService()  {

const accessToken=this.afAuth.auth.currentUser.getToken().then(res=>{
  const httpOptions = {
    headers: new HttpHeaders({
      'Content-Type':  'application/json',
      'Authorization': res
    })
  };
  return this.http.get('Url',httpOptions)
    .subscribe(res => console.log(res));
}); }}

How to reset the state of a Redux store?

I have created actions to clear state. So when I dispatch a logout action creator I dispatch actions to clear state as well.

User record action

export const clearUserRecord = () => ({
  type: CLEAR_USER_RECORD
});

Logout action creator

export const logoutUser = () => {
  return dispatch => {
    dispatch(requestLogout())
    dispatch(receiveLogout())
    localStorage.removeItem('auth_token')
    dispatch({ type: 'CLEAR_USER_RECORD' })
  }
};

Reducer

const userRecords = (state = {isFetching: false,
  userRecord: [], message: ''}, action) => {
  switch (action.type) {
    case REQUEST_USER_RECORD:
    return { ...state,
      isFetching: true}
    case RECEIVE_USER_RECORD:
    return { ...state,
      isFetching: false,
      userRecord: action.user_record}
    case USER_RECORD_ERROR:
    return { ...state,
      isFetching: false,
      message: action.message}
    case CLEAR_USER_RECORD:
    return {...state,
      isFetching: false,
      message: '',
      userRecord: []}
    default:
      return state
  }
};

I am not sure if this is optimal?

Shrink to fit content in flexbox, or flex-basis: content workaround?

I want columns One and Two to shrink/grow to fit rather than being fixed.

Have you tried: flex-basis: auto

or this:

flex: 1 1 auto, which is short for:

  • flex-grow: 1 (grow proportionally)
  • flex-shrink: 1 (shrink proportionally)
  • flex-basis: auto (initial size based on content size)

or this:

main > section:first-child {
    flex: 1 1 auto;
    overflow-y: auto;
}

main > section:nth-child(2) {
    flex: 1 1 auto;
    overflow-y: auto;
}

main > section:last-child {
    flex: 20 1 auto;
    display: flex;
    flex-direction: column;  
}

revised demo

Related:

In CSS Flexbox, why are there no "justify-items" and "justify-self" properties?

I know this doesn't use flexbox, but for the simple use-case of three items (one at left, one at center, one at right), this can be accomplished easily using display: grid on the parent, grid-area: 1/1/1/1; on the children, and justify-self for positioning of those children.

_x000D_
_x000D_
<div style="border: 1px solid red; display: grid; width: 100px; height: 25px;">_x000D_
  <div style="border: 1px solid blue; width: 25px; grid-area: 1/1/1/1; justify-self: left;"></div>_x000D_
  <div style="border: 1px solid blue; width: 25px; grid-area: 1/1/1/1; justify-self: center;"></div>_x000D_
  <div style="border: 1px solid blue; width: 25px; grid-area: 1/1/1/1; justify-self: right;"></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

R * not meaningful for factors ERROR

new[,2] is a factor, not a numeric vector. Transform it first

new$MY_NEW_COLUMN <-as.numeric(as.character(new[,2])) * 5

Disable a link in Bootstrap

I think you need the btn class.
It would be like this:

<a class="btn disabled" href="#">Disabled link</a>

How can I make a CSS glass/blur effect work for an overlay?

Here's a possible solution.

HTML

<img id="source" src="http://www.byui.edu/images/agriculture-life-sciences/flower.jpg" />

<div id="crop">
    <img id="overlay" src="http://www.byui.edu/images/agriculture-life-sciences/flower.jpg" />
</div>

CSS

#crop {
    overflow: hidden;

    position: absolute;
    left: 100px;
    top: 100px;

    width: 450px;
    height: 150px;
}

#overlay {
    -webkit-filter:blur(4px);
    filter:blur(4px);

    width: 450px;
}

#source {
    height: 300px;
    width: auto;
    position: absolute;
    left: 100px;
    top: 100px;
}

I know the CSS can be simplified and you probably should get rid of the ids. The idea here is to use a div as a cropping container and then apply blur on duplicate of the image. Fiddle

To make this work in Firefox, you would have to use SVG hack.

Unable to obtain LocalDateTime from TemporalAccessor when parsing LocalDateTime (Java 8)

For anyone who landed here with this error, like I did:

Unable to obtain LocalDateTime from TemporalAccessor: {HourOfAmPm=0, MinuteOfHour=0}

It came from a the following line:

LocalDateTime.parse(date, DateTimeFormatter.ofPattern("M/d/yy h:mm"));

It turned out that it was because I was using a 12hr Hour pattern on a 0 hour, instead of a 24hr pattern.

Changing the hour to 24hr pattern by using a capital H fixes it:

LocalDateTime.parse(date, DateTimeFormatter.ofPattern("M/d/yy H:mm"));

Eclipse: Java was started but returned error code=13

I also faced the error code when i upgraded my java version to 1.8. The problem was with my eclipse.

My jdk which was installed on my system is of 32 - bit and my eclipse was of 64 - bit.

So solve this problem i downloaded the 32 - bit eclipse.

IMO this Architecture miss match problem

Plese match your architecture type of JDK and eclipse.

"The system cannot find the file C:\ProgramData\Oracle\Java\javapath\java.exe"

Updating the PATH Environment Variable

If you do not set the PATH variable, you need to specify the full path to the executable file every time you run it, such as:

C:\> "C:\Program Files\Java\jdk1.8.0\bin\javac" MyClass.java


It is useful to set the PATH variable permanently so it will persist after rebooting.
To set the PATH variable permanently, add the full path of the jdk1.8.0\bin directory to the PATH variable. Typically, this full path looks something like
C:\Program Files\Java\jdk1.8.0\bin.
Set the PATH variable as follows on Microsoft Windows:

  • Click Start, then Control Panel, then System.
  • Click Advanced, then Environment Variables.
  • Add the location of the bin folder of the JDK installation to the PATH variable in System Variables.
    The following is a typical value for the PATH variable:

    C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files\Java\jdk1.8.0\bin

    Note:

  • The PATH environment variable is a series of directories separated by semicolons (;) and is not case-sensitive. Microsoft Windows looks for programs in the PATH directories in order, from left to right.

  • You should only have one bin directory for a JDK in the path at a time. Those following the first instance are ignored.

  • If you are not sure where to add the JDK path, append it.

The new path takes effect in each new command window you open after setting the PATH variable.

Bootstrap 3 Horizontal Divider (not in a dropdown)

Currently it only works for the .dropdown-menu:

.dropdown-menu .divider {
  height: 1px;
  margin: 9px 0;
  overflow: hidden;
  background-color: #e5e5e5;
}

If you want it for other use, in your own css, following the bootstrap.css create another one:

.divider {
  height: 1px;
  width:100%;
  display:block; /* for use on default inline elements like span */
  margin: 9px 0;
  overflow: hidden;
  background-color: #e5e5e5;
}

Package name does not correspond to the file path - IntelliJ

You should declare in the Project structure(Ctrl+Alt+Shift+s) in the Module section mark your folders which of them are source package(blue one) and which are test ...

How to remove element from array in forEach loop?

You could also use indexOf instead to do this

var i = review.indexOf('\u2022 \u2022 \u2022');
if (i !== -1) review.splice(i,1);

how to get curl to output only http response body (json) and no other headers etc

I was executing a get request an also want to see just the response and nothing else, seems like magic is done with -silent,-s option.

From the curl man page:

-s, --silent Silent or quiet mode. Don't show progress meter or error messages. Makes Curl mute. It will still output the data you ask for, potentially even to the terminal/stdout unless you redirect it.

Below the examples:

curl -s "http://host:8080/some/resource"
curl -silent "http://host:8080/some/resource"

Using custom headers

curl -s -H "Accept: application/json" "http://host:8080/some/resource")

Using POST method with a header

curl -s -X POST -H "Content-Type: application/json" "http://host:8080/some/resource") -d '{ "myBean": {"property": "value"}}'

You can also customize the output for specific values with -w, below the options I use to get just response codes of the curl:

curl -s -o /dev/null -w "%{http_code}" "http://host:8080/some/resource"

How to read html from a url in python 3

urllib.request.urlopen(url).read() should return you the raw HTML page as a string.

How to find what code is run by a button or element in Chrome using Developer Tools

Solution 1: Framework blackboxing

Works great, minimal setup and no third parties.

According to Chrome's documentation:

What happens when you blackbox a script?

Exceptions thrown from library code will not pause (if Pause on exceptions is enabled), Stepping into/out/over bypasses the library code, Event listener breakpoints don't break in library code, The debugger will not pause on any breakpoints set in library code. The end result is you are debugging your application code instead of third party resources.

Here's the updated workflow:
  1. Pop open Chrome Developer Tools (F12 or ?+?+i), go to settings (upper right, or F1). Find a tab on the left called "Blackboxing"

enter image description here

  1. This is where you put the RegEx pattern of the files you want Chrome to ignore while debugging. For example: jquery\..*\.js (glob pattern/human translation: jquery.*.js)
  2. If you want to skip files with multiple patterns you can add them using the pipe character, |, like so: jquery\..*\.js|include\.postload\.js (which acts like an "or this pattern", so to speak. Or keep adding them with the "Add" button.
  3. Now continue to Solution 3 described down below.

Bonus tip! I use Regex101 regularly (but there are many others: ) to quickly test my rusty regex patterns and find out where I'm wrong with the step-by-step regex debugger. If you are not yet "fluent" in Regular Expressions I recommend you start using sites that help you write and visualize them such as http://buildregex.com/ and https://www.debuggex.com/

You can also use the context menu when working in the Sources panel. When viewing a file, you can right-click in the editor and choose Blackbox Script. This will add the file to the list in the Settings panel:

enter image description here


Solution 2: Visual Event

enter image description here

It's an excellent tool to have:

Visual Event is an open-source Javascript bookmarklet which provides debugging information about events that have been attached to DOM elements. Visual Event shows:

  • Which elements have events attached to them
  • The type of events attached to an element
  • The code that will be run with the event is triggered
  • The source file and line number for where the attached function was defined (Webkit browsers and Opera only)


Solution 3: Debugging

You can pause the code when you click somewhere in the page, or when the DOM is modified... and other kinds of JS breakpoints that will be useful to know. You should apply blackboxing here to avoid a nightmare.

In this instance, I want to know what exactly goes on when I click the button.

  1. Open Dev Tools -> Sources tab, and on the right find Event Listener Breakpoints:

    enter image description here

  2. Expand Mouse and select click

  3. Now click the element (execution should pause), and you are now debugging the code. You can go through all code pressing F11 (which is Step in). Or go back a few jumps in the stack. There can be a ton of jumps


Solution 4: Fishing keywords

With Dev Tools activated, you can search the whole codebase (all code in all files) with ?+?+F or:

enter image description here

and searching #envio or whatever the tag/class/id you think starts the party and you may get somewhere faster than anticipated.

Be aware sometimes there's not only an img but lots of elements stacked, and you may not know which one triggers the code.


If this is a bit out of your knowledge, take a look at Chrome's tutorial on debugging.

Saving binary data as file using JavaScript from a browser

This is possible if the browser supports the download property in anchor elements.

var sampleBytes = new Int8Array(4096);

var saveByteArray = (function () {
    var a = document.createElement("a");
    document.body.appendChild(a);
    a.style = "display: none";
    return function (data, name) {
        var blob = new Blob(data, {type: "octet/stream"}),
            url = window.URL.createObjectURL(blob);
        a.href = url;
        a.download = name;
        a.click();
        window.URL.revokeObjectURL(url);
    };
}());

saveByteArray([sampleBytes], 'example.txt');


JSFiddle: http://jsfiddle.net/VB59f/2

Vagrant error : Failed to mount folders in Linux guest

by now the mounting works on some machines (ubuntu) and some doesn't (centos 7) but installing the plugin solves it

vagrant plugin install vagrant-vbguest

without having to do anything else on top of that, just

vagrant reload

Bootstrap Align Image with text

Try using .pull-left to left align image along with text.

Ex:

<p>At the time all text elements goes here.At the time all text elements goes here. At the time all text elements goes here.<img src="images/hello-missing.jpg" class="pull-left img-responsive" style="padding:15px;" /> to uncovering the truth .</p>

What's the location of the JavaFX runtime JAR file, jfxrt.jar, on Linux?

Mine were located here on Ubuntu 18.04 when I installed JavaFX using apt install openjfx (as noted already by @jewelsea above)

/usr/share/java/openjfx/jre/lib/ext/jfxrt.jar
/usr/lib/jvm/java-8-openjdk-amd64/jre/lib/ext/jfxrt.jar

Running powershell script within python script, how to make python print the powershell output while it is running

I don't have Python 2.7 installed, but in Python 3.3 calling Popen with stdout set to sys.stdout worked just fine. Not before I had escaped the backslashes in the path, though.

>>> import subprocess
>>> import sys
>>> p = subprocess.Popen(['powershell.exe', 'C:\\Temp\\test.ps1'], stdout=sys.stdout)
>>> Hello World
_

Bootstrap 3 .img-responsive images are not responsive inside fieldset in FireFox

In my case I only wanted the image to behave responsively at mobile scale so I created a css style .myimgrsfix that only kicks in at mobile scale

.myimgrsfix {
    @media(max-width:767px){
        width:100%;
    }
}

and applied that to the image <img class='img-responsive myimgrsfix' src='whatever.gif'>

json: cannot unmarshal object into Go value of type

Here's a fixed version of it: http://play.golang.org/p/w2ZcOzGHKR

The biggest fix that was needed is when Unmarshalling an array, that property needs to be an array/slice in the struct as well.

For example:

{ "things": ["a", "b", "c"] }

Would Unmarshal into a:

type Item struct {
    Things []string
}

And not into:

type Item struct {
    Things string
}

The other thing to watch out for when Unmarshaling is that the types line up exactly. It will fail when Unmarshalling a JSON string representation of a number into an int or float field -- "1" needs to Unmarshal into a string, not into an int like we saw with ShippingAdditionalCost int

Replace non-ASCII characters with a single space

What about this one?

def replace_trash(unicode_string):
     for i in range(0, len(unicode_string)):
         try:
             unicode_string[i].encode("ascii")
         except:
              #means it's non-ASCII
              unicode_string=unicode_string[i].replace(" ") #replacing it with a single space
     return unicode_string

Bootstrap 3 : Vertically Center Navigation Links when Logo Increasing The Height of Navbar

add this to your stylesheet. line-height should match the height of your logo

.navbar-nav li a {
 line-height: 50px;
}

Check out the fiddle at: http://jsfiddle.net/nD4tW/

How to select some rows with specific rownames from a dataframe?

df <- data.frame(x=rnorm(10), y=rnorm(10))
rownames(df) <-  letters[1:10]
df[c('a','b'),]

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 13: ordinal not in range(128)

I got this error when trying to install a python package in a Docker container. For me, the issue was that the docker image did not have a locale configured. Adding the following code to the Dockerfile solved the problem for me.

# Avoid ascii errors when reading files in Python
RUN apt-get install -y locales && locale-gen en_US.UTF-8
ENV LANG='en_US.UTF-8' LANGUAGE='en_US:en' LC_ALL='en_US.UTF-8'

How to simulate POST request?

It would be helpful if you provided more information - e.g. what OS your using, what you want to accomplish, etc. But, generally speaking cURL is a very powerful command-line tool I frequently use (in linux) for imitating HTML requests:

For example:

curl --data "post1=value1&post2=value2&etc=valetc" http://host/resource

OR, for a RESTful API:

curl -X POST -d @file http://host/resource

You can check out more information here-> http://curl.haxx.se/


EDITs:

OK. So basically you're looking to stress test your REST server? Then cURL really isn't helpful unless you want to write your own load-testing program, even then sockets would be the way to go. I would suggest you check out Gatling. The Gatling documentation explains how to set up the tool, and from there your can run all kinds of GET, POST, PUT and DELETE requests.

Unfortunately, short of writing your own program - i.e. spawning a whole bunch of threads and inundating your REST server with different types of requests - you really have to rely on a stress/load-testing toolkit. Just using a REST client to send requests isn't going to put much stress on your server.


More EDITs

So in order to simulate a post request on a socket, you basically have to build the initial socket connection with the server. I am not a C# guy, so I can't tell you exactly how to do that; I'm sure there are 1001 C# socket tutorials on the web. With most RESTful APIs you usually need to provide a URI to tell the server what to do. For example, let's say your API manages a library, and you are using a POST request to tell the server to update information about a book with an id of '34'. Your URI might be

http://localhost/library/book/34

Therefore, you should open a connection to localhost on port 80 (or 8080, or whatever port your server is on), and pass along an HTML request header. Going with the library example above, your request header might look as follows:

POST library/book/34 HTTP/1.0\r\n
X-Requested-With: XMLHttpRequest\r\n
Content-Type: text/html\r\n
Referer: localhost\r\n
Content-length: 36\r\n\r\n
title=Learning+REST&author=Some+Name

From here, the server should shoot back a response header, followed by whatever the API is programed to tell the client - usually something to say the POST succeeded or failed. To stress test your API, you should essentially do this over and over again by creating a threaded process.

Also, if you are posting JSON data, you will have to alter your header and content accordingly. Frankly, if you are looking to do this quick and clean, I would suggest using python (or perl) which has several libraries for creating POST, PUT, GET and DELETE request, as well as POSTing and PUTing JSON data. Otherwise, you might end up doing more programming than stress testing. Hope this helps!

Content Security Policy "data" not working for base64 Images in Chrome 28

According to the grammar in the CSP spec, you need to specify schemes as scheme:, not just scheme. So, you need to change the image source directive to:

img-src 'self' data:;

How to find files recursively by file type and copy them to a directory while in ssh?

Paul Dardeau answer is perfect, the only thing is, what if all the files inside those folders are not PDF files and you want to grab it all no matter the extension. Well just change it to

find . -name "*.*" -type f -exec cp {} ./pdfsfolder \;

Just to sum up!

How to use z-index in svg elements?

There is no z-index for svgs. But svg determines which of your elements are the uppermost by theire position in the DOM. Thus you can remove the Object and place it to the end of the svg making it the "last rendered" element. That one is then rendered "topmost" visually.


Using jQuery:

function moveUp(thisObject){
    thisObject.appendTo(thisObject.parents('svg>g'));
}

usage:

moveUp($('#myTopElement'));

Using D3.js:

d3.selection.prototype.moveUp = function() {
    return this.each(function() {
        this.parentNode.appendChild(this);
    });
};

usage:

myTopElement.moveUp();

How to get some values from a JSON string in C#?

my string

var obj = {"Status":0,"Data":{"guid":"","invitationGuid":"","entityGuid":"387E22AD69-4910-430C-AC16-8044EE4A6B24443545DD"},"Extension":null}

Following code to get guid:

var userObj = JObject.Parse(obj);
var userGuid = Convert.ToString(userObj["Data"]["guid"]);

python 3.2 UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 9629: character maps to <undefined>

When you open the file you want to write to, open it with a specific encoding that can handle all the characters.

with open('filename', 'w', encoding='utf-8') as f:
    print(r['body'], file=f)

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

My solotion for responsive/dropdown navbar with angular-ui bootstrap (when update to angular 1.5 and, ui-bootrap 1.2.1)
index.html

     ...    
    <link rel="stylesheet" href="/css/app.css">
</head>
<body>


<nav class="navbar navbar-inverse navbar-fixed-top">
        <div class="container">
            <input type="checkbox" id="navbar-toggle-cbox">
            <div class="navbar-header">
                <label for="navbar-toggle-cbox" class="navbar-toggle" 
                       ng-init="navCollapsed = true" 
                       ng-click="navCollapsed = !navCollapsed"  
                       aria-controls="navbar">
                    <span class="sr-only">Toggle navigation</span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                </label>
                <a class="navbar-brand" href="#">Project name</a>
                 <div id="navbar" class="collapse navbar-collapse"  ng-class="{'in':!navCollapsed}">
                    <ul class="nav navbar-nav">
                        <li class="active"><a href="/view1">Home</a></li>
                        <li><a href="/view2">About</a></li>
                        <li><a href="#">Contact</a></li>
                        <li uib-dropdown>
                            <a href="#" uib-dropdown-toggle>Dropdown <b class="caret"></b></a>
                            <ul uib-dropdown-menu role="menu" aria-labelledby="split-button">
                                <li role="menuitem"><a href="#">Action</a></li>
                                <li role="menuitem"><a href="#">Another action</a></li>                                   
                            </ul>
                        </li>

                    </ul>
                 </div>
            </div>
        </div>
    </nav>

app.css

/* show the collapse when navbar toggle is checked */
#navbar-toggle-cbox:checked ~ .collapse {
    display: block;
}

/* the checkbox used only internally; don't display it */
#navbar-toggle-cbox {
  display:none
}

Counter exit code 139 when running, but gdb make it through

exit code 139 (people say this means memory fragmentation)

No, it means that your program died with signal 11 (SIGSEGV on Linux and most other UNIXes), also known as segmentation fault.

Could anybody tell me why the run fails but debug doesn't?

Your program exhibits undefined behavior, and can do anything (that includes appearing to work correctly sometimes).

Your first step should be running this program under Valgrind, and fixing all errors it reports.

If after doing the above, the program still crashes, then you should let it dump core (ulimit -c unlimited; ./a.out) and then analyze that core dump with GDB: gdb ./a.out core; then use where command.

Invalid character in identifier

A little bit late but I got the same error and I realized that it was because I copied some code from a PDF. Check the difference between these two: - - The first one is from hitting the minus sign on keyboard and the second is from a latex generated PDF.

UnicodeEncodeError: 'charmap' codec can't encode - character maps to <undefined>, print function

For debugging purposes, you could use print(repr(data)).

To display text, always print Unicode. Don't hardcode the character encoding of your environment such as Cp850 inside your script. To decode the HTTP response, see A good way to get the charset/encoding of an HTTP response in Python.

To print Unicode to Windows console, you could use win-unicode-console package.

move div with CSS transition

transition-property:width;

This should work. you have to have browser dependent code

How to upgrade rubygems

Install rubygems-update

gem install rubygems-update
update_rubygems
gem update --system

run this commands as root or use sudo.

select data up to a space?

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

How to fix 'Microsoft Excel cannot open or save any more documents'

Go to this key on Registry Editor (Run | Regedit) HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

change key Cache to something like C:\Windows\Temp

My similar problem was solved like this.

Regards,

Ripley

how to save canvas as png image?

var canvasId = chart.id + '-canvas';
var canvasDownloadId = chart.id + '-download-canvas';
var canvasHtml = Ext.String.format('<canvas id="{0}" width="{1}" height="{2}"></canvas><a id="{3}"/>',
canvasId,
chart.getWidth(),
chart.getHeight(),
canvasDownloadId);
var canvasElement = reportBuilder.add({ html: canvasHtml });

var canvas = document.getElementById(canvasId);

var canvasDownload = document.getElementById(canvasDownloadId);
canvasDownload.href = chart.getImage().data;
canvasDownload.download = 'chart';

canvasDownload.click();

Not receiving Google OAuth refresh token

Rich Sutton's answer finally worked for me, after I realized that adding access_type=offline is done on the front end client's request for an authorization code, not the back end request that exchanges that code for an access_token. I've added a comment to his answer and this link at Google for more info about refreshing tokens.

P.S. If you are using Satellizer, here is how to add that option to the $authProvider.google in AngularJS.

How to convert image into byte array and byte array to base64 String in android?

Try this:

// convert from bitmap to byte array
public byte[] getBytesFromBitmap(Bitmap bitmap) {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    bitmap.compress(CompressFormat.JPEG, 70, stream);
    return stream.toByteArray();
}

// get the base 64 string
String imgString = Base64.encodeToString(getBytesFromBitmap(someImg), 
                       Base64.NO_WRAP);

Why fragments, and when to use fragments instead of activities?

Fragments lives within the Activity and has:

  • its own lifecycle
  • its own layout
  • its own child fragments and etc.

Think of Fragments as a sub activity of the main activity it belongs to, it cannot exist of its own and it can be called/reused again and again. Hope this helps :)

Python string to unicode

Decode it with the unicode-escape codec:

>>> a="Hello\u2026"
>>> a.decode('unicode-escape')
u'Hello\u2026'
>>> print _
Hello…

This is because for a non-unicode string the \u2026 is not recognised but is instead treated as a literal series of characters (to put it more clearly, 'Hello\\u2026'). You need to decode the escapes, and the unicode-escape codec can do that for you.

Note that you can get unicode to recognise it in the same way by specifying the codec argument:

>>> unicode(a, 'unicode-escape')
u'Hello\u2026'

But the a.decode() way is nicer.

javascript - pass selected value from popup window to parent window input box

If you want a popup window rather than a <div />, I would suggest the following approach.

In your parent page, you call a small helper method to show the popup window:

<input type="button" name="choice" onClick="selectValue('sku1')" value="?">

Add the following JS methods:

function selectValue(id)
{
    // open popup window and pass field id
    window.open('sku.php?id=' + encodeURIComponent(id),'popuppage',
      'width=400,toolbar=1,resizable=1,scrollbars=yes,height=400,top=100,left=100');
}

function updateValue(id, value)
{
    // this gets called from the popup window and updates the field with a new value
    document.getElementById(id).value = value;
}

Your sku.php receives the selected field via $_GET['id'] and uses it to construct the parent callback function:

?>
<script type="text/javascript">
function sendValue(value)
{
    var parentId = <?php echo json_encode($_GET['id']); ?>;
    window.opener.updateValue(parentId, value);
    window.close();
}
</script>

For each row in your popup, change code to this:

<td><input type=button value="Select" onClick="sendValue('<?php echo $rows['packcode']; ?>')" /></td>

Following this approach, the popup window doesn't need to know how to update fields in the parent form.

How to parse JSON without JSON.NET library?

I use this...but have never done any metro app development, so I don't know of any restrictions on libraries available to you. (note, you'll need to mark your classes as with DataContract and DataMember attributes)

public static class JSONSerializer<TType> where TType : class
{
    /// <summary>
    /// Serializes an object to JSON
    /// </summary>
    public static string Serialize(TType instance)
    {
        var serializer = new DataContractJsonSerializer(typeof(TType));
        using (var stream = new MemoryStream())
        {
            serializer.WriteObject(stream, instance);
            return Encoding.Default.GetString(stream.ToArray());
        }
    }

    /// <summary>
    /// DeSerializes an object from JSON
    /// </summary>
    public static TType DeSerialize(string json)
    {
        using (var stream = new MemoryStream(Encoding.Default.GetBytes(json)))
        {
            var serializer = new DataContractJsonSerializer(typeof(TType));
            return serializer.ReadObject(stream) as TType;
        }
    }
}

So, if you had a class like this...

[DataContract]
public class MusicInfo
{
    [DataMember]
    public string Name { get; set; }

    [DataMember]
    public string Artist { get; set; }

    [DataMember]
    public string Genre { get; set; }

    [DataMember]
    public string Album { get; set; }

    [DataMember]
    public string AlbumImage { get; set; }

    [DataMember]
    public string Link { get; set; }

}

Then you would use it like this...

var musicInfo = new MusicInfo
{
     Name = "Prince Charming",
     Artist = "Metallica",
     Genre = "Rock and Metal",
     Album = "Reload",
     AlbumImage = "http://up203.siz.co.il/up2/u2zzzw4mjayz.png",
     Link = "http://f2h.co.il/7779182246886"
};

// This will produce a JSON String
var serialized = JSONSerializer<MusicInfo>.Serialize(musicInfo);

// This will produce a copy of the instance you created earlier
var deserialized = JSONSerializer<MusicInfo>.DeSerialize(serialized);

Eclipse hangs on loading workbench

The procedure shown at http://off-topic.biz/en/eclipse-hangs-at-startup-showing-only-the-splash-screen/ worked for me:

  1. cd .metadata/.plugins
  2. mv org.eclipse.core.resources org.eclipse.core.resources.bak
  3. Start eclipse. (It should show an error message or an empty workspace because no project is found.)
  4. Close all open editors tabs.
  5. Exit eclipse.
  6. rm -rf org.eclipse.core.resources (Delete the newly created directory.)
  7. mv org.eclipse.core.resources.bak/ org.eclipse.core.resources (Restore the original directory.)
  8. Start eclipse and start working. :-)

In other answers:

eclipse -clean -clearPersistedState

is mentioned - which seems to have the same or even better effect.

Here is a script for MacOS (using Macports) and Linux (tested on Ubuntu with Eclipse Equinox) to do the start with an an optional kill of the running eclipse. You might want to adapt the script to your needs. If you add new platforms please edit the script right in this answer.

#!/bin/bash
# WF 2014-03-14
#
# ceclipse:
#   start Eclipse cleanly
#
#   this script calls eclipse with -clean and -clearPersistedState
#   if an instance of eclipse is already running the user is asked
#   if it should be killed first and if answered yes the process will be killed
#
# usage: ceclipse
#

#
# error
#
#   show an error message and exit
#
#   params:
#     1: l_msg - the message to display
error() {
  local l_msg="$1"
  echo "error: $l_msg" 1>&2
  exit 1 
}

#
# autoinstall
#
#  check that l_prog is available by calling which
#  if not available install from given package depending on Operating system
#
#  params: 
#    1: l_prog: The program that shall be checked
#    2: l_linuxpackage: The apt-package to install from
#    3: l_macospackage: The MacPorts package to install from
#
autoinstall() {
  local l_prog=$1
  local l_linuxpackage=$2
  local l_macospackage=$3
  echo "checking that $l_prog  is installed on os $os ..."
  which $l_prog 
  if [ $? -eq 1 ]
  then
    case $os in 
      # Mac OS
      Darwin) 
        echo "installing $l_prog from MacPorts package $l_macospackage"        
        sudo port install $l_macospackage
      ;;
      # e.g. Ubuntu/Fedora/Debian/Suse
      Linux)
        echo "installing $l_prog from apt-package $l_linuxpackage"        
        sudo apt-get install $l_linuxpackage
      ;;
      # git bash (Windows)
      MINGW32_NT-6.1)
        error "$l_prog ist not installed"
      ;;
      *)
        error "unknown operating system $os" 
    esac
  fi
}

# global operating system variable
os=`uname`

# first set 
#  eclipse_proc - the name of the eclipse process to look for
#  eclipse_app - the name of the eclipse application to start
case $os in 
    # Mac OS
    Darwin) 
      eclipse_proc="Eclipse.app" 
      eclipse_app="/Applications/eclipse/Eclipse.app/Contents/MacOS/eclipse"
      ;;
    # e.g. Ubuntu/Fedora/Debian/Suse
    Linux)
      eclipse_proc="/usr/lib/eclipse//plugins/org.eclipse.equinox.launcher_1.2.0.dist.jar"
      eclipse_app=`which eclipse`
      ;;
    # git bash (Windows)
    MINGW32_NT-6.1)
      eclipse_app=`which eclipse`
      error "$os not implemented yet"
      ;;
    *)
      error "unknown operating system $os" 
esac

# check that pgrep is installed or install it
autoinstall pgrep procps

# check whether eclipse process is running
# first check that we only find one process
echo "looking for $eclipse_proc process"
pgrep -fl "$eclipse_proc"
# can't use -c option on MacOS - use platform independent approach 
#eclipse_count=`pgrep -cfl "$eclipse_proc"`
eclipse_count=`pgrep -fl "$eclipse_proc" | wc -l | tr -d ' '`

# check how many processes matched
case $eclipse_count in
  # no eclipse - do nothing
  0) ;;
  # exactly one - offer to kill it
  1) 
     echo "Eclipse is running - shall i kill and restart it with -clean? y/n?"
       read answer
       case $answer in
         y|Y) ;;
           *) error "aborted ..." ;;
       esac
     echo "killing current $eclipse_proc"
     pkill -f "$eclipse_proc"
     ;;
  # multiple - this is bogus
  *) error "$eclipse_count processes matching $eclipse_proc found - please adapt $0";;
esac

tmp=/tmp/eclipse$$
echo "starting eclipse cleanly ... using $tmp for nohup.out"
mkdir -p $tmp
cd $tmp

# start eclipse with clean options
nohup $eclipse_app -clean -clearPersistedState&

How to convert JSON to CSV format and store in a variable

Here is the latest answer using a well optimized and nice csv plugin: (The code may not work on stackoverflow here but will work in your project as i have tested it myself)

Using jquery and jquery.csv library (Very well optimized and perfectly escapes everything) https://github.com/typeiii/jquery-csv

_x000D_
_x000D_
// Create an array of objects
const data = [
    { name: "Item 1", color: "Green", size: "X-Large" },
    { name: "Item 2", color: "Green", size: "X-Large" },
    { name: "Item 3", color: "Green", size: "X-Large" }
];

// Convert to csv
const csv = $.csv.fromObjects(data);

// Download file as csv function
const downloadBlobAsFile = function(csv, filename){
    var downloadLink = document.createElement("a");
    var blob = new Blob([csv], { type: 'text/csv' });
    var url = URL.createObjectURL(blob);
    downloadLink.href = url;
    downloadLink.download = filename;
    document.body.appendChild(downloadLink);
    downloadLink.click();
    document.body.removeChild(downloadLink);
}

// Download csv file
downloadBlobAsFile(csv, 'filename.csv');
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdn.tutorialjinni.com/jquery-csv/1.0.11/jquery.csv.min.js"></script>
_x000D_
_x000D_
_x000D_

jQuery `.is(":visible")` not working in Chrome

If you read the jquery docs, there are numerous reasons for something to not be considered visible/hidden:

They have a CSS display value of none.

They are form elements with type="hidden".

Their width and height are explicitly set to 0.

An ancestor element is hidden, so the element is not shown on the page.

http://api.jquery.com/visible-selector/

Here's a small jsfiddle example with one visible and one hidden element:

http://jsfiddle.net/tNjLb/

Getting RSA private key from PEM BASE64 Encoded private key file

As others have responded, the key you are trying to parse doesn't have the proper PKCS#8 headers which Oracle's PKCS8EncodedKeySpec needs to understand it. If you don't want to convert the key using openssl pkcs8 or parse it using JDK internal APIs you can prepend the PKCS#8 header like this:

static final Base64.Decoder DECODER = Base64.getMimeDecoder();

private static byte[] buildPKCS8Key(File privateKey) throws IOException {
  final String s = new String(Files.readAllBytes(privateKey.toPath()));
  if (s.contains("--BEGIN PRIVATE KEY--")) {
    return DECODER.decode(s.replaceAll("-----\\w+ PRIVATE KEY-----", ""));
  }
  if (!s.contains("--BEGIN RSA PRIVATE KEY--")) {
    throw new RuntimeException("Invalid cert format: "+ s);
  }

  final byte[] innerKey = DECODER.decode(s.replaceAll("-----\\w+ RSA PRIVATE KEY-----", ""));
  final byte[] result = new byte[innerKey.length + 26];
  System.arraycopy(DECODER.decode("MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKY="), 0, result, 0, 26);
  System.arraycopy(BigInteger.valueOf(result.length - 4).toByteArray(), 0, result, 2, 2);
  System.arraycopy(BigInteger.valueOf(innerKey.length).toByteArray(), 0, result, 24, 2);
  System.arraycopy(innerKey, 0, result, 26, innerKey.length);
  return result;
}

Once that method is in place you can feed it's output to the PKCS8EncodedKeySpec constructor like this: new PKCS8EncodedKeySpec(buildPKCS8Key(privateKey));

How to send FormData objects with Ajax-requests in jQuery?

I believe you could do it like this :

var fd = new FormData();    
fd.append( 'file', input.files[0] );

$.ajax({
  url: 'http://example.com/script.php',
  data: fd,
  processData: false,
  contentType: false,
  type: 'POST',
  success: function(data){
    alert(data);
  }
});

Notes:

  • Setting processData to false lets you prevent jQuery from automatically transforming the data into a query string. See the docs for more info.

  • Setting the contentType to false is imperative, since otherwise jQuery will set it incorrectly.

How do I test if a recordSet is empty? isNull?

A simple way is to write it:

Dim rs As Object
Set rs = Me.Recordset.Clone
If Me.Recordset.RecordCount = 0 then 'checks for number of records
   msgbox "There is no records" 
End if

enum Values to NSString (iOS)

This will be validated by compiler, so you won't mix up indices accidentally.

NSDictionary *stateStrings =
 @{
   @(MCSessionStateNotConnected) : @"MCSessionStateNotConnected",
   @(MCSessionStateConnecting) : @"MCSessionStateConnecting",
   @(MCSessionStateConnected) : @"MCSessionStateConnected",
  };
NSString *stateString = [stateStrings objectForKey:@(state)];

var stateStrings: [MCSessionState: String] = [
    .notConnected : "MCSessionState.notConnected",
    .connecting : "MCSessionState.connecting",
    .connected : "MCSessionState.connected"
]
var stateString = stateStrings[MCSessionState.Connected]

UPDATE: A more Swifty way is to extend the enum with CustomStringConvertible conformance. Also, this way the compiler will safeguard to implement every new addition to the underlying enum (whereas using arrays does not), as switch statements must be exhaustive.

extension MCSessionState: CustomStringConvertible {
    
    public var description: String {
        switch self {
        case .notConnected:
            return "MCSessionState.notConnected"
        case .connecting:
            return "MCSessionState.connecting"
        case .connected:
            return "MCSessionState.connected"
        @unknown default:
            return "Unknown"
        }
    }
}

// You can use it like this.
var stateString = MCSessionState.connected.description

// Or this.
var stateString = "\(MCSessionState.connected)"

Creating Unicode character from its number

Unfortunatelly, to remove one backlash as mentioned in first comment (newbiedoodle) don't lead to good result. Most (if not all) IDE issues syntax error. The reason is in this, that Java Escaped Unicode format expects syntax "\uXXXX", where XXXX are 4 hexadecimal digits, which are mandatory. Attempts to fold this string from pieces fails. Of course, "\u" is not the same as "\\u". The first syntax means escaped 'u', second means escaped backlash (which is backlash) followed by 'u'. It is strange, that on the Apache pages is presented utility, which doing exactly this behavior. But in reality, it is Escape mimic utility. Apache has some its own utilities (i didn't testet them), which do this work for you. May be, it is still not that, what you want to have. Apache Escape Unicode utilities But this utility 1 have good approach to the solution. With combination described above (MeraNaamJoker). My solution is create this Escaped mimic string and then convert it back to unicode (to avoid real Escaped Unicode restriction). I used it for copying text, so it is possible, that in uencode method will be better to use '\\u' except '\\\\u'. Try it.

  /**
   * Converts character to the mimic unicode format i.e. '\\u0020'.
   * 
   * This format is the Java source code format.
   * 
   *   CharUtils.unicodeEscaped(' ') = "\\u0020"
   *   CharUtils.unicodeEscaped('A') = "\\u0041"
   * 
   * @param ch  the character to convert
   * @return is in the mimic of escaped unicode string, 
   */
  public static String unicodeEscaped(char ch) {
    String returnStr;
    //String uniTemplate = "\u0000";
    final static String charEsc = "\\u";

    if (ch < 0x10) {
      returnStr = "000" + Integer.toHexString(ch);
    }
    else if (ch < 0x100) {
      returnStr = "00" + Integer.toHexString(ch);
    }
    else if (ch < 0x1000) {
      returnStr = "0" + Integer.toHexString(ch);
    }
    else
      returnStr = "" + Integer.toHexString(ch);

    return charEsc + returnStr;
  }

  /**
   * Converts the string from UTF8 to mimic unicode format i.e. '\\u0020'.
   * notice: i cannot use real unicode format, because this is immediately translated
   * to the character in time of compiling and editor (i.e. netbeans) checking it
   * instead reaal unicode format i.e. '\u0020' i using mimic unicode format '\\u0020'
   * as a string, but it doesn't gives the same results, of course
   * 
   * This format is the Java source code format.
   * 
   *   CharUtils.unicodeEscaped(' ') = "\\u0020"
   *   CharUtils.unicodeEscaped('A') = "\\u0041"
   * 
   * @param String - nationalString in the UTF8 string to convert
   * @return is the string in JAVA unicode mimic escaped
   */
  public String encodeStr(String nationalString) throws UnsupportedEncodingException {
    String convertedString = "";

    for (int i = 0; i < nationalString.length(); i++) {
      Character chs = nationalString.charAt(i);
      convertedString += unicodeEscaped(chs);
    }
    return convertedString;
  }

  /**
   * Converts the string from mimic unicode format i.e. '\\u0020' back to UTF8.
   * 
   * This format is the Java source code format.
   * 
   *   CharUtils.unicodeEscaped(' ') = "\\u0020"
   *   CharUtils.unicodeEscaped('A') = "\\u0041"
   * 
   * @param String - nationalString in the JAVA unicode mimic escaped
   * @return is the string in UTF8 string
   */
  public String uencodeStr(String escapedString) throws UnsupportedEncodingException {
    String convertedString = "";

    String[] arrStr = escapedString.split("\\\\u");
    String str, istr;
    for (int i = 1; i < arrStr.length; i++) {
      str = arrStr[i];
      if (!str.isEmpty()) {
        Integer iI = Integer.parseInt(str, 16);
        char[] chaCha = Character.toChars(iI);
        convertedString += String.valueOf(chaCha);
      }
    }
    return convertedString;
  }

UnicodeEncodeError: 'ascii' codec can't encode character u'\u2013' in position 3 2: ordinal not in range(128)

I had the same problem. This work fine for me:

str(objdata).encode('utf-8')

what does this mean ? image/png;base64?

That data:image/png;base64 URL is cool, I’ve never run into it before. The long encrypted link is the actual image, i.e. no image call to the server. See RFC 2397 for details.

Side note: I have had trouble getting larger base64 images to render on IE8. I believe IE8 has a 32K limit that can be problematic for larger files. See this other StackOverflow thread for details.

C++ - unable to start correctly (0xc0150002)

I faced this issue, when I was supplying the executable folder with a, by the .exe requested DLL. In my case, the DLL I supplied to the .exe was searching for another necessary DLL which was not available. The searching DLL was not capable of telling that it can not find the necessary DLL.

You might check the DLLs you're loading and the dependencies of these DLL's.

PHP session handling errors

When using latest WHM (v66.0.23) you may go to MultiPHP INI Editor choose PHP version and set session.save_path to default i.e. /var/cpanel/php/sessions/ea-php70 instead of previous simple tmp - this helped me to get rid of such errors.

Android SDK installation doesn't find JDK

Non of these solutions worked for me. I fixed it by temporarily changing the filename of C:\Windows\System32\java.exe to java_.exe

UnicodeEncodeError: 'latin-1' codec can't encode character

Character U+201C Left Double Quotation Mark is not present in the Latin-1 (ISO-8859-1) encoding.

It is present in code page 1252 (Western European). This is a Windows-specific encoding that is based on ISO-8859-1 but which puts extra characters into the range 0x80-0x9F. Code page 1252 is often confused with ISO-8859-1, and it's an annoying but now-standard web browser behaviour that if you serve your pages as ISO-8859-1, the browser will treat them as cp1252 instead. However, they really are two distinct encodings:

>>> u'He said \u201CHello\u201D'.encode('iso-8859-1')
UnicodeEncodeError
>>> u'He said \u201CHello\u201D'.encode('cp1252')
'He said \x93Hello\x94'

If you are using your database only as a byte store, you can use cp1252 to encode and other characters present in the Windows Western code page. But still other Unicode characters which are not present in cp1252 will cause errors.

You can use encode(..., 'ignore') to suppress the errors by getting rid of the characters, but really in this century you should be using UTF-8 in both your database and your pages. This encoding allows any character to be used. You should also ideally tell MySQL you are using UTF-8 strings (by setting the database connection and the collation on string columns), so it can get case-insensitive comparison and sorting right.

Python base64 data decode

Interesting if maddening puzzle...but here's the best I could get:

The data seems to repeat every 8 bytes or so.

import struct
import base64

target = \
r'''Q5YACgAAAABDlgAbAAAAAEOWAC0AAAAAQ5YAPwAAAABDlgdNAAAAAEOWB18AAAAAQ5YH 
[snip.]
ZAAAAABExxniAAAAAETH/rQAAAAARMf/MwAAAABEx/+yAAAAAETIADEAAAAA''' 

data = base64.b64decode(target)

cleaned_data = []
struct_format = ">ff"
for i in range(len(data) // 8):
   cleaned_data.append(struct.unpack_from(struct_format, data, 8*i))

That gives output like the following (a sampling of lines from the first 100 or so):

(300.00030517578125, 0.0)
(300.05975341796875, 241.93943786621094)
(301.05612182617187, 0.0)
(301.05667114257812, 8.7439727783203125)
(326.9617919921875, 0.0)
(326.96826171875, 0.0)
(328.34432983398438, 280.55218505859375)

That first number does seem to monotonically increase through the entire set. If you plot it:

import matplotlib.pyplot as plt
f, ax = plt.subplots()
ax.plot(*zip(*cleaned_data))

enter image description here

format = 'hhhh' (possibly with various paddings/directions (e.g. '<hhhh', '<xhhhh') also might be worth a look (again, random lines):

(-27069, 2560, 0, 0)
(-27069, 8968, 0, 0)
(-27069, 13576, 3139, -18487)
(-27069, 18184, 31043, -5184)
(-27069, -25721, -25533, -8601)
(-27069, -7289, 0, 0)
(-25533, 31066, 0, 0)
(-25533, -29350, 0, 0)
(-25533, 25179, 0, 0)
(-24509, -1888, 0, 0)
(-24509, -4447, 0, 0)
(-23741, -14725, 32067, 27475)
(-23741, -3973, 0, 0)
(-23485, 4908, -29629, -20922)

How to Load RSA Private Key From File

Two things. First, you must base64 decode the mykey.pem file yourself. Second, the openssl private key format is specified in PKCS#1 as the RSAPrivateKey ASN.1 structure. It is not compatible with java's PKCS8EncodedKeySpec, which is based on the SubjectPublicKeyInfo ASN.1 structure. If you are willing to use the bouncycastle library you can use a few classes in the bouncycastle provider and bouncycastle PKIX libraries to make quick work of this.

import java.io.BufferedReader;
import java.io.FileReader;
import java.security.KeyPair;
import java.security.Security;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.PEMKeyPair;
import org.bouncycastle.openssl.PEMParser;
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;

// ...   

String keyPath = "mykey.pem";
BufferedReader br = new BufferedReader(new FileReader(keyPath));
Security.addProvider(new BouncyCastleProvider());
PEMParser pp = new PEMParser(br);
PEMKeyPair pemKeyPair = (PEMKeyPair) pp.readObject();
KeyPair kp = new JcaPEMKeyConverter().getKeyPair(pemKeyPair);
pp.close();
samlResponse.sign(Signature.getInstance("SHA1withRSA").toString(), kp.getPrivate(), certs);

Python Unicode Encode Error

Don't hardcode the character encoding of your environment inside your script; print Unicode text directly instead:

assert isinstance(text, unicode) # or str on Python 3
print(text)

If your output is redirected to a file (or a pipe); you could use PYTHONIOENCODING envvar, to specify the character encoding:

$ PYTHONIOENCODING=utf-8 python your_script.py >output.utf8

Otherwise, python your_script.py should work as is -- your locale settings are used to encode the text (on POSIX check: LC_ALL, LC_CTYPE, LANG envvars -- set LANG to a utf-8 locale if necessary).

To print Unicode on Windows, see this answer that shows how to print Unicode to Windows console, to a file, or using IDLE.

Changing Locale within the app itself

In Android M the top solution won't work. I've written a helper class to fix that which you should call from your Application class and all Activities (I would suggest creating a BaseActivity and then make all the Activities inherit from it.

Note: This will also support properly RTL layout direction.

Helper class:

public class LocaleUtils {

    private static Locale sLocale;

    public static void setLocale(Locale locale) {
        sLocale = locale;
        if(sLocale != null) {
            Locale.setDefault(sLocale);
        }
    }

    public static void updateConfig(ContextThemeWrapper wrapper) {
        if(sLocale != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            Configuration configuration = new Configuration();
            configuration.setLocale(sLocale);
            wrapper.applyOverrideConfiguration(configuration);
        }
    }

    public static void updateConfig(Application app, Configuration configuration) {
        if (sLocale != null && Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
            //Wrapping the configuration to avoid Activity endless loop
            Configuration config = new Configuration(configuration);
            // We must use the now-deprecated config.locale and res.updateConfiguration here,
            // because the replacements aren't available till API level 24 and 17 respectively.
            config.locale = sLocale;
            Resources res = app.getBaseContext().getResources();
            res.updateConfiguration(config, res.getDisplayMetrics());
        }
    }
}

Application:

public class App extends Application {
    public void onCreate(){
        super.onCreate();

        LocaleUtils.setLocale(new Locale("iw"));
        LocaleUtils.updateConfig(this, getBaseContext().getResources().getConfiguration());
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        LocaleUtils.updateConfig(this, newConfig);
    }
}

BaseActivity:

public class BaseActivity extends Activity {
    public BaseActivity() {
        LocaleUtils.updateConfig(this);
    }
}

How to resolve javax.mail.AuthenticationFailedException issue?

You need to implement a custom Authenticator

import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;


class GMailAuthenticator extends Authenticator {
     String user;
     String pw;
     public GMailAuthenticator (String username, String password)
     {
        super();
        this.user = username;
        this.pw = password;
     }
    public PasswordAuthentication getPasswordAuthentication()
    {
       return new PasswordAuthentication(user, pw);
    }
}

Now use it in the Session

Session session = Session.getInstance(props, new GMailAuthenticator(username, password));

Also check out the JavaMail FAQ

Can't connect to MySQL server error 111

If you're running cPanel/WHM, make sure that IP is whitelisted in the firewall. You will als need to add that IP to the remote SQL IP list in the cPanel account you're trying to connect to.

Ball to Ball Collision - Detection and Handling

I implemented this code in JavaScript using the HTML Canvas element, and it produced wonderful simulations at 60 frames per second. I started the simulation off with a collection of a dozen balls at random positions and velocities. I found that at higher velocities, a glancing collision between a small ball and a much larger one caused the small ball to appear to STICK to the edge of the larger ball, and moved up to around 90 degrees around the larger ball before separating. (I wonder if anyone else observed this behavior.)

Some logging of the calculations showed that the Minimum Translation Distance in these cases was not large enough to prevent the same balls from colliding in the very next time step. I did some experimenting and found that I could solve this problem by scaling up the MTD based on the relative velocities:

dot_velocity = ball_1.velocity.dot(ball_2.velocity);
mtd_factor = 1. + 0.5 * Math.abs(dot_velocity * Math.sin(collision_angle));
mtd.multplyScalar(mtd_factor);

I verified that before and after this fix, the total kinetic energy was conserved for every collision. The 0.5 value in the mtd_factor was the approximately the minumum value found to always cause the balls to separate after a collision.

Although this fix introduces a small amount of error in the exact physics of the system, the tradeoff is that now very fast balls can be simulated in a browser without decreasing the time step size.

Character reading from file in Python

This is Pythons way do show you unicode encoded strings. But i think you should be able to print the string on the screen or write it into a new file without any problems.

>>> test = u"I don\u2018t like this"
>>> test
u'I don\u2018t like this'
>>> print test
I don‘t like this

Understanding the Rails Authenticity Token

What happens

When the user views a form to create, update, or destroy a resource, the Rails app creates a random authenticity_token, stores this token in the session, and places it in a hidden field in the form. When the user submits the form, Rails looks for the authenticity_token, compares it to the one stored in the session, and if they match the request is allowed to continue.

Why it happens

Since the authenticity token is stored in the session, the client cannot know its value. This prevents people from submitting forms to a Rails app without viewing the form within that app itself. Imagine that you are using service A, you logged into the service and everything is ok. Now imagine that you went to use service B, and you saw a picture you like, and pressed on the picture to view a larger size of it. Now, if some evil code was there at service B, it might send a request to service A (which you are logged into), and ask to delete your account, by sending a request to http://serviceA.com/close_account. This is what is known as CSRF (Cross Site Request Forgery).

If service A is using authenticity tokens, this attack vector is no longer applicable, since the request from service B would not contain the correct authenticity token, and will not be allowed to continue.

API docs describes details about meta tag:

CSRF protection is turned on with the protect_from_forgery method, which checks the token and resets the session if it doesn't match what was expected. A call to this method is generated for new Rails applications by default. The token parameter is named authenticity_token by default. The name and value of this token must be added to every layout that renders forms by including csrf_meta_tags in the HTML head.

Notes

Keep in mind, Rails only verifies not idempotent methods (POST, PUT/PATCH and DELETE). GET request are not checked for authenticity token. Why? because the HTTP specification states that GET requests is idempotent and should not create, alter, or destroy resources at the server, and the request should be idempotent (if you run the same command multiple times, you should get the same result every time).

Also the real implementation is a bit more complicated as defined in the beginning, ensuring better security. Rails does not issue the same stored token with every form. Neither does it generate and store a different token every time. It generates and stores a cryptographic hash in a session and issues new cryptographic tokens, which can be matched against the stored one, every time a page is rendered. See request_forgery_protection.rb.

Lessons

Use authenticity_token to protect your not idempotent methods (POST, PUT/PATCH, and DELETE). Also make sure not to allow any GET requests that could potentially modify resources on the server.


EDIT: Check the comment by @erturne regarding GET requests being idempotent. He explains it in a better way than I have done here.

How can I recover the return value of a function passed to multiprocessing.Process?

Thought I'd simplify the simplest examples copied from above, working for me on Py3.6. Simplest is multiprocessing.Pool:

import multiprocessing
import time

def worker(x):
    time.sleep(1)
    return x

pool = multiprocessing.Pool()
print(pool.map(worker, range(10)))

You can set the number of processes in the pool with, e.g., Pool(processes=5). However it defaults to CPU count, so leave it blank for CPU-bound tasks. (I/O-bound tasks often suit threads anyway, as the threads are mostly waiting so can share a CPU core.) Pool also applies chunking optimization.

(Note that the worker method cannot be nested within a method. I initially defined my worker method inside the method that makes the call to pool.map, to keep it all self-contained, but then the processes couldn't import it, and threw "AttributeError: Can't pickle local object outer_method..inner_method". More here. It can be inside a class.)

(Appreciate the original question specified printing 'represent!' rather than time.sleep(), but without it I thought some code was running concurrently when it wasn't.)


Py3's ProcessPoolExecutor is also two lines (.map returns a generator so you need the list()):

from concurrent.futures import ProcessPoolExecutor
with ProcessPoolExecutor() as executor:
    print(list(executor.map(worker, range(10))))

With plain Processes:

import multiprocessing
import time

def worker(x, queue):
    time.sleep(1)
    queue.put(x)

queue = multiprocessing.SimpleQueue()
tasks = range(10)

for task in tasks:
    multiprocessing.Process(target=worker, args=(task, queue,)).start()

for _ in tasks:
    print(queue.get())

Use SimpleQueue if all you need is put and get. The first loop starts all the processes, before the second makes the blocking queue.get calls. I don't think there's any reason to call p.join() too.

Retrofit and GET using parameters

AFAIK, {...} can only be used as a path, not inside a query-param. Try this instead:

public interface FooService {    

    @GET("/maps/api/geocode/json?sensor=false")
    void getPositionByZip(@Query("address") String address, Callback<String> cb);
}

If you have an unknown amount of parameters to pass, you can use do something like this:

public interface FooService {    

    @GET("/maps/api/geocode/json")
    @FormUrlEncoded
    void getPositionByZip(@FieldMap Map<String, String> params, Callback<String> cb);
}

Firefox setting to enable cross domain Ajax request

To allow cross domain:

  1. enter about:config
  2. accept to be careful
  3. enter security.fileuri.strict_origin_policy in the search bar
  4. change to false

You can now close the tab. Normally you can now make cross domain request with this config.

See here for more details.

Shorten string without cutting words in JavaScript

You can use truncate one-liner below:

_x000D_
_x000D_
const text = "The string that I want to truncate!";_x000D_
_x000D_
const truncate = (str, len) => str.substring(0, (str + ' ').lastIndexOf(' ', len));_x000D_
_x000D_
console.log(truncate(text, 14));
_x000D_
_x000D_
_x000D_

Sum all the elements java arraylist

I haven't tested it but it should work.

public double incassoMargherita()
{
    double sum = 0;
    for(int i = 0; i < m.size(); i++)
    {
        sum = sum + m.get(i);
    }
    return sum;
}

How do I animate constraint changes?

Generally, you just need to update constraints and call layoutIfNeeded inside the animation block. This can be either changing the .constant property of an NSLayoutConstraint, adding remove constraints (iOS 7), or changing the .active property of constraints (iOS 8 & 9).

Sample Code:

[UIView animateWithDuration:0.3 animations:^{
    // Move to right
    self.leadingConstraint.active = false;
    self.trailingConstraint.active = true;

    // Move to bottom
    self.topConstraint.active = false;
    self.bottomConstraint.active = true;

    // Make the animation happen
    [self.view setNeedsLayout];
    [self.view layoutIfNeeded];
}];

Sample Setup:

Xcode Project so sample animation project.

Controversy

There are some questions about whether the constraint should be changed before the animation block, or inside it (see previous answers).

The following is a Twitter conversation between Martin Pilkington who teaches iOS, and Ken Ferry who wrote Auto Layout. Ken explains that though changing constants outside of the animation block may currently work, it's not safe and they should really be change inside the animation block. https://twitter.com/kongtomorrow/status/440627401018466305

Animation:

Sample Project

Here's a simple project showing how a view can be animated. It's using Objective C and animates the view by changing the .active property of several constraints. https://github.com/shepting/SampleAutoLayoutAnimation

Using JQuery to check if no radio button in a group has been checked

I think this is a simple example, how to check if a radio in a group of radios was checked.

if($('input[name=html_elements]:checked').length){
    //a radio button was checked
}else{
    //there was no radio button checked
} 

Java generics - ArrayList initialization

You can't assign a List<Number> to a reference of type List<Integer> because List<Number> allows types of numbers other than Integer. If you were allowed to do that, the following would be allowed:

List<Number> numbers = new ArrayList<Number>();
numbers.add(1.1); // add a double
List<Integer> ints = numbers;
Integer fail = ints.get(0); // ClassCastException!

The type List<Integer> is making a guarantee that anything it contains will be an Integer. That's why you're allowed to get an Integer out of it without casting. As you can see, if the compiler allowed a List of another type such as Number to be assigned to a List<Integer> that guarantee would be broken.

Assigning a List<Integer> to a reference of a type such as List<?> or List<? extends Number> is legal because the ? means "some unknown subtype of the given type" (where the type is Object in the case of just ? and Number in the case of ? extends Number).

Since ? indicates that you do not know what specific type of object the List will accept, it isn't legal to add anything but null to it. You are, however, allowed to retrieve any object from it, which is the purpose of using a ? extends X bounded wildcard type. Note that the opposite is true for a ? super X bounded wildcard type... a List<? super Integer> is "a list of some unknown type that is at least a supertype of Integer". While you don't know exactly what type of List it is (could be List<Integer>, List<Number>, List<Object>) you do know for sure that whatever it is, an Integer can be added to it.

Finally, new ArrayList<?>() isn't legal because when you're creating an instance of a paramterized class like ArrayList, you have to give a specific type parameter. You could really use whatever in your example (Object, Foo, it doesn't matter) since you'll never be able to add anything but null to it since you're assigning it directly to an ArrayList<?> reference.

How to create a self-signed certificate for a domain name for development?

With IIS's self-signed certificate feature, you cannot set the common name (CN) for the certificate, and therefore cannot create a certificate bound to your choice of subdomain.

One way around the problem is to use makecert.exe, which is bundled with the .Net 2.0 SDK. On my server it's at:

C:\Program Files\Microsoft.Net\SDK\v2.0 64bit\Bin\makecert.exe

You can create a signing authority and store it in the LocalMachine certificates repository as follows (these commands must be run from an Administrator account or within an elevated command prompt):

makecert.exe -n "CN=My Company Development Root CA,O=My Company,
 OU=Development,L=Wallkill,S=NY,C=US" -pe -ss Root -sr LocalMachine
 -sky exchange -m 120 -a sha1 -len 2048 -r

You can then create a certificate bound to your subdomain and signed by your new authority:

(Note that the the value of the -in parameter must be the same as the CN value used to generate your authority above.)

makecert.exe -n "CN=subdomain.example.com" -pe -ss My -sr LocalMachine
 -sky exchange -m 120 -in "My Company Development Root CA" -is Root
 -ir LocalMachine -a sha1 -eku 1.3.6.1.5.5.7.3.1

Your certificate should then appear in IIS Manager to be bound to your site as explained in Tom Hall's post.

All kudos for this solution to Mike O'Brien for his excellent blog post at http://www.mikeobrien.net/blog/creating-self-signed-wildcard

How do you read a CSV file and display the results in a grid in Visual Basic 2010?

For Each line As String In System.IO.File.ReadAllLines("D:\abc.csv")
    DataGridView1.Rows.Add(line.Split(","))
Next

horizontal line and right way to code it in html, css

I'd go for semantic markup, use an <hr/>.

Unless it's just a border what you want, then you can use a combination of padding, border and margin, to get the desired bound.

How to find the files that are created in the last hour in unix

UNIX filesystems (generally) don't store creation times. Instead, there are only access time, (data) modification time, and (inode) change time.

That being said, find has -atime -mtime -ctime predicates:

$ man 1 find
...
-ctime  n
        The primary shall evaluate as true if the time of last change of
        file status information subtracted from the initialization time,
        divided by 86400 (with any remainder discarded), is n.
...

Thus find -ctime 0 finds everything for which the inode has changed (e.g. includes file creation, but also counts link count and permissions and filesize change) less than an hour ago.

SQL JOIN vs IN performance?

The optimizer should be smart enough to give you the same result either way for normal queries. Check the execution plan and they should give you the same thing. If they don't, I would normally consider the JOIN to be faster. All systems are different, though, so you should profile the code on your system to be sure.

How to make node.js require absolute? (instead of relative)

Just want to follow up on the great answer from Paolo Moretti and Browserify. If you are using a transpiler (e.g., babel, typescript) and you have separate folders for source and transpiled code like src/ and dist/, you could use a variation of the solutions as

node_modules

With the following directory structure:

app
  node_modules
    ... // normal npm dependencies for app
  src
    node_modules
      app
        ... // source code
  dist
    node_modules
      app
        ... // transpiled code

you can then let babel etc to transpile src directory to dist directory.

symlink

Using symlink we can get rid some levels of nesting:

app
  node_modules
    ... // normal npm dependencies for app
  src
    node_modules
      app // symlinks to '..'
    ... // source code
  dist
    node_modules
      app // symlinks to '..'
    ... // transpiled code

A caveat with babel --copy-files The --copy-files flag of babel does not deal with symlinks well. It may keep navigating into the .. symlink and recusively seeing endless files. A workaround is to use the following directory structure:

app
  node_modules
    app // symlink to '../src'
    ... // normal npm dependencies for app
  src
    ... // source code
  dist
    node_modules
      app // symlinks to '..'
    ... // transpiled code

In this way, code under src will still have app resolved to src, whereas babel would not see symlinks anymore.

How can I set Image source with base64

Try using setAttribute instead:

document.getElementById('img')
    .setAttribute(
        'src', 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=='
    );

Real answer: (And make sure you remove the line-breaks in the base64.)

Maintain image aspect ratio when changing height

I have been playing around flexbox lately and i came to solution for this through experimentation and the following reasoning. However, in reality I'm not sure if this is exactly what happens.

If real width is affected by flex system. So after width of elements hit max width of parent they extra width set in css is ignored. Then it's safe to set width to 100%.

Since height of img tag is derived from image itself then setting height to 0% could do something. (this is where i am unclear as to what...but it made sense to me that it should fix it)

DEMO

(remember saw it here first!)

.slider {
    display: flex;
}
.slider img {
    height: 0%;
    width: 100%;
    margin: 0 5px;
}

Works only in chrome yet

How do I restrict an input to only accept numbers?

All the above solutions are quite large, i wanted to give my 2 cents on this.

I am only checking if the value inputed is a number or not, and checking if it's not blank, that's all.

Here is the html:

<input type="text" ng-keypress="CheckNumber()"/>

Here is the JS:

$scope.CheckKey = function () {
    if (isNaN(event.key) || event.key === ' ' || event.key === '') {
        event.returnValue = '';
    }
};

It's quite simple.

I belive this wont work on Paste tho, just so it's known.

For Paste, i think you would need to use the onChange event and parse the whole string, quite another beast the tamme. This is specific for typing.

UPDATE for Paste: just add this JS function:

$scope.CheckPaste = function () {
    var paste = event.clipboardData.getData('text');

    if (isNaN(paste)) {
        event.preventDefault();
        return false;
    }
};

And the html input add the trigger:

<input type="text" ng-paste="CheckPaste()"/>

I hope this helps o/

What is the path for the startup folder in windows 2008 server

You can easily reach them by using the Run window and entering:

shell:startup

and

shell:common startup

Source.

How to list all databases in the mongo shell?

For database list:

show databases
show dbs

For table/collection list:

show collections
show tables
db.getCollectionNames()

How to generate xsd from wsdl

(WHEN .wsdl is referring to .xsd/schemas using import) If you're using the WMB Tooklit (v8.0.0.4 WMB) then you can find .xsd using following steps :

Create library (optional) > Right Click , New Message Model File > Select SOAP XML > Choose Option 'I already have WSDL for my data' > 'Select file outside workspace' > 'Select the WSDL bindings to Import' (if there are multiple) > Finish.

This will give you the .xsd and .wsdl files in your Workspace (Application Perspective).

Change Button color onClick

There are indeed global variables in javascript. You can learn more about scopes, which are helpful in this situation.

Your code could look like this:

<script>
    var count = 1;
    function setColor(btn, color) {
        var property = document.getElementById(btn);
        if (count == 0) {
            property.style.backgroundColor = "#FFFFFF"
            count = 1;        
        }
        else {
            property.style.backgroundColor = "#7FFF00"
            count = 0;
        }
    }
</script>

Hope this helps.

What is the difference between task and thread?

I usually use Task to interact with Winforms and simple background worker to make it not freezing the UI. here an example when I prefer using Task

private async void buttonDownload_Click(object sender, EventArgs e)
{
    buttonDownload.Enabled = false;
    await Task.Run(() => {
        using (var client = new WebClient())
        {
            client.DownloadFile("http://example.com/file.mpeg", "file.mpeg");
        }
    })
    buttonDownload.Enabled = true;
}

VS

private void buttonDownload_Click(object sender, EventArgs e)
{
    buttonDownload.Enabled = false;
    Thread t = new Thread(() =>
    {
        using (var client = new WebClient())
        {
            client.DownloadFile("http://example.com/file.mpeg", "file.mpeg");
        }
        this.Invoke((MethodInvoker)delegate()
        {
            buttonDownload.Enabled = true;
        });
    });
    t.IsBackground = true;
    t.Start();
}

the difference is you don't need to use MethodInvoker and shorter code.

Role/Purpose of ContextLoaderListener in Spring?

Your understanding is correct. I wonder why you don't see any advantages in ContextLoaderListener. For example, you need to build a session factory (to manage database). This operation can take some time, so it's better to do it on startup. Of course you can do it with init servlets or something else, but the advantage of Spring's approach is that you make configuration without writing code.

Iterate through Nested JavaScript Objects

In case you want to deeply iterate into a complex (nested) object for each key & value, you can do so using Object.keys(), recursively:

const iterate = (obj) => {
    Object.keys(obj).forEach(key => {

    console.log(`key: ${key}, value: ${obj[key]}`)

    if (typeof obj[key] === 'object') {
            iterate(obj[key])
        }
    })
}

REPL example.

What is the ideal data type to use when storing latitude / longitude in a MySQL database?

We store latitude/longitude X 1,000,000 in our oracle database as NUMBERS to avoid round off errors with doubles.

Given that latitude/longitude to the 6th decimal place was 10 cm accuracy that was all we needed. Many other databases also store lat/long to the 6th decimal place.

Understanding `scale` in R

This is a late addition but I was looking for information on the scale function myself and though it might help somebody else as well.

To modify the response from Ricardo Saporta a little bit.
Scaling is not done using standard deviation, at least not in version 3.6.1 of R, I base this on "Becker, R. (2018). The new S language. CRC Press." and my own experimentation.

X.man.scaled <- X/sqrt(sum(X^2)/(length(X)-1))
X.aut.scaled <- scale(X, center = F)

The result of these rows are exactly the same, I show it without centering because of simplicity.

I would respond in a comment but did not have enough reputation.

Reorder HTML table rows using drag-and-drop

Apparently the question poorly describes the OP's problem, but this question is the top search result for dragging to reorder table rows, so that is what I will answer. I wasn't interested in bringing in jQuery UI for something so simple, so here is a jQuery only solution:

_x000D_
_x000D_
$(".grab").mousedown(function(e) {
  var tr = $(e.target).closest("TR"),
    si = tr.index(),
    sy = e.pageY,
    b = $(document.body),
    drag;
  if (si == 0) return;
  b.addClass("grabCursor").css("userSelect", "none");
  tr.addClass("grabbed");

  function move(e) {
    if (!drag && Math.abs(e.pageY - sy) < 10) return;
    drag = true;
    tr.siblings().each(function() {
      var s = $(this),
        i = s.index(),
        y = s.offset().top;
      if (i > 0 && e.pageY >= y && e.pageY < y + s.outerHeight()) {
        if (i < tr.index())
          tr.insertAfter(s);
        else
          tr.insertBefore(s);
        return false;
      }
    });
  }

  function up(e) {
    if (drag && si != tr.index()) {
      drag = false;
      alert("moved!");
    }
    $(document).unbind("mousemove", move).unbind("mouseup", up);
    b.removeClass("grabCursor").css("userSelect", "none");
    tr.removeClass("grabbed");
  }
  $(document).mousemove(move).mouseup(up);
});
_x000D_
.grab {
  cursor: grab;
}

.grabbed {
  box-shadow: 0 0 13px #000;
}

.grabCursor,
.grabCursor * {
  cursor: grabbing !important;
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<table>
  <tr>
    <th></th>
    <th>Table Header</th>
  </tr>
  <tr>
    <td class="grab">&#9776;</td>
    <td>Table Cell 1</td>
  </tr>
  <tr>
    <td class="grab">&#9776;</td>
    <td>Table Cell 2</td>
  </tr>
  <tr>
    <td class="grab">&#9776;</td>
    <td>Table Cell 3</td>
  </tr>
</table>
_x000D_
_x000D_
_x000D_

Note si == 0 and i > 0 ignores the first row, which for me contains TH tags. Replace the alert with your "drag finished" logic.

Typing the Enter/Return key using Python and Selenium

You just do this:

final private WebElement input = driver.findElement(By.id("myId"));
input.clear();
input.sendKeys(value); // The value we want to set to input
input.sendKeys(Keys.RETURN);

What's the best way to get the current URL in Spring MVC?

Java's URI Class can help you out of this:

public static String getCurrentUrl(HttpServletRequest request){
    URL url = new URL(request.getRequestURL().toString());
    String host  = url.getHost();
    String userInfo = url.getUserInfo();
    String scheme = url.getProtocol();
    String port = url.getPort();
    String path = request.getAttribute("javax.servlet.forward.request_uri");
    String query = request.getAttribute("javax.servlet.forward.query_string");

    URI uri = new URI(scheme,userInfo,host,port,path,query,null)
    return uri.toString();
}

How To Execute SSH Commands Via PHP

Use the ssh2 functions. Anything you'd do via an exec() call can be done directly using these functions, saving you a lot of connections and shell invocations.

How to center a checkbox in a table cell?

My problem was that there was a parent style with position: absolute !important which I was not allowed to edit.

So I gave my specific checkbox position: relative !important and it fixed the vertical misalignment issue.

Difference between SelectedItem, SelectedValue and SelectedValuePath

To answer a little more conceptually:

SelectedValuePath defines which property (by its name) of the objects bound to the ListBox's ItemsSource will be used as the item's SelectedValue.

For example, if your ListBox is bound to a collection of Person objects, each of which has Name, Age, and Gender properties, SelectedValuePath=Name will cause the value of the selected Person's Name property to be returned in SelectedValue.

Note that if you override the ListBox's ControlTemplate (or apply a Style) that specifies what property should display, SelectedValuePath cannot be used.

SelectedItem, meanwhile, returns the entire Person object currently selected.

(Here's a further example from MSDN, using TreeView)

Update: As @Joe pointed out, the DisplayMemberPath property is unrelated to the Selected* properties. Its proper description follows:

Note that these values are distinct from DisplayMemberPath (which is defined on ItemsControl, not Selector), but that property has similar behavior to SelectedValuePath: in the absence of a style/template, it identifies which property of the object bound to item should be used as its string representation.

How to insert multiple rows from array using CodeIgniter framework?

Assembling one INSERT statement with multiple rows is much faster in MySQL than one INSERT statement per row.

That said, it sounds like you might be running into string-handling problems in PHP, which is really an algorithm problem, not a language one. Basically, when working with large strings, you want to minimize unnecessary copying. Primarily, this means you want to avoid concatenation. The fastest and most memory efficient way to build a large string, such as for inserting hundreds of rows at one, is to take advantage of the implode() function and array assignment.

$sql = array(); 
foreach( $data as $row ) {
    $sql[] = '("'.mysql_real_escape_string($row['text']).'", '.$row['category_id'].')';
}
mysql_query('INSERT INTO table (text, category) VALUES '.implode(',', $sql));

The advantage of this approach is that you don't copy and re-copy the SQL statement you've so far assembled with each concatenation; instead, PHP does this once in the implode() statement. This is a big win.

If you have lots of columns to put together, and one or more are very long, you could also build an inner loop to do the same thing and use implode() to assign the values clause to the outer array.

Windows 7 SDK installation failure

Uninstalling all C++ redistributables and unchecking the C++ option worked for me. Note that I have VS2010 SP1, and VS2012 installed already.

How to resolve Error : Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation

This error can be resolved by adding MessageBoxOptions.ServiceNotification.

MessageBox.Show(msg, "Print Error", System.Windows.Forms.MessageBoxButtons.YesNo, 
   System.Windows.Forms.MessageBoxIcon.Error,     
   System.Windows.Forms.MessageBoxDefaultButton.Button1, 
   System.Windows.Forms.MessageBoxOptions.ServiceNotification); 

But it is not going to show any dialog box if your web application is installed on IIS or server.Because in IIS or server it is hosted on worker process which dont have any desktop.

Get list of Excel files in a folder using VBA

Ok well this might work for you, a function that takes a path and returns an array of file names in the folder. You could use an if statement to get just the excel files when looping through the array.

Function listfiles(ByVal sPath As String)

    Dim vaArray     As Variant
    Dim i           As Integer
    Dim oFile       As Object
    Dim oFSO        As Object
    Dim oFolder     As Object
    Dim oFiles      As Object

    Set oFSO = CreateObject("Scripting.FileSystemObject")
    Set oFolder = oFSO.GetFolder(sPath)
    Set oFiles = oFolder.Files

    If oFiles.Count = 0 Then Exit Function

    ReDim vaArray(1 To oFiles.Count)
    i = 1
    For Each oFile In oFiles
        vaArray(i) = oFile.Name
        i = i + 1
    Next

    listfiles = vaArray

End Function

It would be nice if we could just access the files in the files object by index number but that seems to be broken in VBA for whatever reason (bug?).

HTML5 Video not working in IE 11

It was due to IE Document-mode version too low. Press 'F12' and using higher version( My case, above version 9 is OK)

overlay a smaller image on a larger image python OpenCv

A simple 4on4 pasting function that works-

def paste(background,foreground,pos=(0,0)):
    #get position and crop pasting area if needed
    x = pos[0]
    y = pos[1]
    bgWidth = background.shape[0]
    bgHeight = background.shape[1]
    frWidth = foreground.shape[0]
    frHeight = foreground.shape[1]
    width = bgWidth-x
    height = bgHeight-y
    if frWidth<width:
        width = frWidth
    if frHeight<height:
        height = frHeight
    # normalize alpha channels from 0-255 to 0-1
    alpha_background = background[x:x+width,y:y+height,3] / 255.0
    alpha_foreground = foreground[:width,:height,3] / 255.0
    # set adjusted colors
    for color in range(0, 3):
        fr = alpha_foreground * foreground[:width,:height,color]
        bg = alpha_background * background[x:x+width,y:y+height,color] * (1 - alpha_foreground)
        background[x:x+width,y:y+height,color] = fr+bg
    # set adjusted alpha and denormalize back to 0-255
    background[x:x+width,y:y+height,3] = (1 - (1 - alpha_foreground) * (1 - alpha_background)) * 255
    return background

How to evaluate a math expression given in string form?

import java.util.*;

public class check { 
   int ans;
   String str="7 + 5";
   StringTokenizer st=new StringTokenizer(str);

   int v1=Integer.parseInt(st.nextToken());
   String op=st.nextToken();
   int v2=Integer.parseInt(st.nextToken());

   if(op.equals("+")) { ans= v1 + v2; }
   if(op.equals("-")) { ans= v1 - v2; }
   //.........
}

Is there a SELECT ... INTO OUTFILE equivalent in SQL Server Management Studio?

In SSMS, "Query" menu item... "Results to"... "Results to File"

Shortcut = CTRL+shift+F

You can set it globally too

"Tools"... "Options"... "Query Results"... "SQL Server".. "Default destination" drop down

Edit: after comment

In SSMS, "Query" menu item... "SQLCMD" mode

This allows you to run "command line" like actions.

A quick test in my SSMS 2008

:OUT c:\foo.txt
SELECT * FROM sys.objects

Edit, Sep 2012

:OUT c:\foo.txt
SET NOCOUNT ON;SELECT * FROM sys.objects

What is the way of declaring an array in JavaScript?

If you are creating an array whose main feature is it's length, rather than the value of each index, defining an array as var a=Array(length); is appropriate.

eg-

String.prototype.repeat= function(n){
    n= n || 1;
    return Array(n+1).join(this);
}

What's the best way to identify hidden characters in the result of a query in SQL Server (Query Analyzer)?

Create a function that addresses all the whitespace possibilites and enable only those that seem appropriate:

SELECT dbo.ShowWhiteSpace(myfield) from mytable

Uncomment only those whitespace cases you want to test for:


CREATE FUNCTION dbo.ShowWhiteSpace (@str varchar(8000))
RETURNS varchar(8000)
AS
BEGIN
     DECLARE @ShowWhiteSpace varchar(8000);
     SET @ShowWhiteSpace = @str
     SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(32), '[?]')
     SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(13), '[CR]')
     SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(10), '[LF]')
     SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(9),  '[TAB]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(1),  '[SOH]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(2),  '[STX]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(3),  '[ETX]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(4),  '[EOT]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(5),  '[ENQ]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(6),  '[ACK]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(7),  '[BEL]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(8),  '[BS]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(11), '[VT]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(12), '[FF]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(14), '[SO]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(15), '[SI]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(16), '[DLE]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(17), '[DC1]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(18), '[DC2]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(19), '[DC3]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(20), '[DC4]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(21), '[NAK]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(22), '[SYN]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(23), '[ETB]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(24), '[CAN]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(25), '[EM]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(26), '[SUB]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(27), '[ESC]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(28), '[FS]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(29), '[GS]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(30), '[RS]')
--   SET @ShowWhiteSpace = REPLACE( @ShowWhiteSpace, CHAR(31), '[US]')
     RETURN(@ShowWhiteSpace)
END

Could not transfer artifact org.apache.maven.plugins:maven-surefire-plugin:pom:2.7.1 from/to central (http://repo1.maven.org/maven2)

This is solved for me when I update maven and check the option "Force update of Snapshots/Releases" in Eclipse. this clears all errors. So right click on project -> Maven -> update project, then check the above option -> Ok. Hope this helps you.

Checking if date is weekend PHP

For guys like me, who aren't minimalistic, there is a PECL extension called "intl". I use it for idn conversion since it works way better than the "idn" extension and some other n1 classes like "IntlDateFormatter".

Well, what I want to say is, the "intl" extension has a class called "IntlCalendar" which can handle many international countries (e.g. in Saudi Arabia, sunday is not a weekend day). The IntlCalendar has a method IntlCalendar::isWeekend for that. Maybe you guys give it a shot, I like that "it works for almost every country" fact on these intl-classes.

EDIT: Not quite sure but since PHP 5.5.0, the intl extension is bundled with PHP (--enable-intl).

How to turn NaN from parseInt into 0 for an empty string?

I created a 2 prototype to handle this for me, one for a number, and one for a String.

// This is a safety check to make sure the prototype is not already defined.
Function.prototype.method = function (name, func) {
    if (!this.prototype[name]) {
        this.prototype[name] = func;
        return this;
    }
};

// returns the int value or -1 by default if it fails
Number.method('tryParseInt', function (defaultValue) {
    return parseInt(this) == this ? parseInt(this) : (defaultValue === undefined ? -1 : defaultValue);
});

// returns the int value or -1 by default if it fails
String.method('tryParseInt', function (defaultValue) {
    return parseInt(this) == this ? parseInt(this) : (defaultValue === undefined ? -1 : defaultValue);
});

If you dont want to use the safety check, use

String.prototype.tryParseInt = function(){
    /*Method body here*/
};
Number.prototype.tryParseInt = function(){
     /*Method body here*/
};

Example usage:

var test = 1;
console.log(test.tryParseInt()); // returns 1

var test2 = '1';
console.log(test2.tryParseInt()); // returns 1

var test3 = '1a';
console.log(test3.tryParseInt()); // returns -1 as that is the default

var test4 = '1a';
console.log(test4.tryParseInt(0));// returns 0, the specified default value

How to describe table in SQL Server 2008?

You can use keyboard short-cut for Description/ detailed information of Table in SQL Server 2008.

Follow steps:

  1. Write Table Name,
  2. Select it, and press Alt + F1
  3. It will show detailed information/ description of mentioned table as,

    1) Table created date,
    2) Columns Description,
    3) Identity,
    4) Indexes,
    5) Constraints,
    6) References etc. As shown Below [example]:

Alt+F1 Demo

Enable SQL Server Broker taking too long

Enabling SQL Server Service Broker requires a database lock. Stop the SQL Server Agent and then execute the following:

USE master ;
GO

ALTER DATABASE [MyDatabase] SET ENABLE_BROKER ;
GO

Change [MyDatabase] with the name of your database in question and then start SQL Server Agent.

If you want to see all the databases that have Service Broker enabled or disabled, then query sys.databases, for instance:

SELECT
    name, database_id, is_broker_enabled
FROM sys.databases

How do I set up cron to run a file just once at a specific time?

You really want to use at. It is exactly made for this purpose.

echo /usr/bin/the_command options | at now + 1 day

However if you don't have at, or your hosting company doesn't provide access to it, you could make a self-deleting cron entry.

Sadly, this will remove all your cron entries. However, if you only have one, this is fine.

0 0 2 12 * crontab -r ; /home/adm/bin/the_command options

The command crontab -r removes your crontab entry. Luckily the rest of the command line will still execute.

WARNING: This is dangerous! It removes ALL cron entries. If you have many, this will remove them all, not just the one that has the "crontab -r" line!

Create Test Class in IntelliJ

I can see some people have asked, so on OSX you can still go to navigate->test or use cmd+shift+T

Remember you have to be focused in the class for this to work

PHP Deprecated: Methods with the same name

As mentioned in the error, the official manual and the comments:

Replace

public function TSStatus($host, $queryPort)

with

public function __construct($host, $queryPort)

Notice: Undefined variable: _SESSION in "" on line 9

First, you'll need to add session_start() at the top of any page that you wish to use SESSION variables on.

Also, you should check to make sure the variable is set first before using it:

if(isset($_SESSION['SESS_fname'])){
    echo $_SESSION['SESS_fname'];
}

Or, simply:

echo (isset($_SESSION['SESS_fname']) ? $_SESSION['SESS_fname'] : "Visitor");

Get an element by index in jQuery

You could skip the jquery and just use CSS style tagging:

 <ul>
 <li>India</li>
 <li>Indonesia</li>
 <li style="background-color:#343434;">China</li>
 <li>United States</li>
 <li>United Kingdom</li>
 </ul>

Is this very likely to create a memory leak in Tomcat?

I added the following to @PreDestroy method in my CDI @ApplicationScoped bean, and when I shutdown TomEE 1.6.0 (tomcat7.0.39, as of today), it clears the thread locals.

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package pf;

import java.lang.ref.WeakReference;
import java.lang.reflect.Array;
import java.lang.reflect.Field;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 * @author Administrator
 * 
 * google-gson issue # 402: Memory Leak in web application; comment # 25
 * https://code.google.com/p/google-gson/issues/detail?id=402
 */
public class ThreadLocalImmolater {

    final Logger logger = LoggerFactory.getLogger(ThreadLocalImmolater.class);

    Boolean debug;

    public ThreadLocalImmolater() {
        debug = true;
    }

    public Integer immolate() {
        int count = 0;
        try {
            final Field threadLocalsField = Thread.class.getDeclaredField("threadLocals");
            threadLocalsField.setAccessible(true);
            final Field inheritableThreadLocalsField = Thread.class.getDeclaredField("inheritableThreadLocals");
            inheritableThreadLocalsField.setAccessible(true);
            for (final Thread thread : Thread.getAllStackTraces().keySet()) {
                    count += clear(threadLocalsField.get(thread));
                    count += clear(inheritableThreadLocalsField.get(thread));
            }
            logger.info("immolated " + count + " values in ThreadLocals");
        } catch (Exception e) {
            throw new Error("ThreadLocalImmolater.immolate()", e);
        }
        return count;
    }

    private int clear(final Object threadLocalMap) throws Exception {
        if (threadLocalMap == null)
                return 0;
        int count = 0;
        final Field tableField = threadLocalMap.getClass().getDeclaredField("table");
        tableField.setAccessible(true);
        final Object table = tableField.get(threadLocalMap);
        for (int i = 0, length = Array.getLength(table); i < length; ++i) {
            final Object entry = Array.get(table, i);
            if (entry != null) {
                final Object threadLocal = ((WeakReference)entry).get();
                if (threadLocal != null) {
                    log(i, threadLocal);
                    Array.set(table, i, null);
                    ++count;
                }
            }
        }
        return count;
    }

    private void log(int i, final Object threadLocal) {
        if (!debug) {
            return;
        }
        if (threadLocal.getClass() != null &&
            threadLocal.getClass().getEnclosingClass() != null &&
            threadLocal.getClass().getEnclosingClass().getName() != null) {

            logger.info("threadLocalMap(" + i + "): " +
                        threadLocal.getClass().getEnclosingClass().getName());
        }
        else if (threadLocal.getClass() != null &&
                 threadLocal.getClass().getName() != null) {
            logger.info("threadLocalMap(" + i + "): " + threadLocal.getClass().getName());
        }
        else {
            logger.info("threadLocalMap(" + i + "): cannot identify threadlocal class name");
        }
    }

}

Please explain the exec() function and its family

The exec(3,3p) functions replace the current process with another. That is, the current process stops, and another runs instead, taking over some of the resources the original program had.

linq where list contains any in list

If you use HashSet instead of List for listofGenres you can do:

var genres = new HashSet<Genre>() { "action", "comedy" };   
var movies = _db.Movies.Where(p => genres.Overlaps(p.Genres));

Finding and removing non ascii characters from an Oracle Varchar2

Do this, it will work.

trim(replace(ntwk_slctor_key_txt, chr(0), ''))

jQuery Event Keypress: Which key was pressed?

Try this

$('#searchbox input').bind('keypress', function(e) {
    if(e.keyCode==13){
        // Enter pressed... do anything here...
    }
});

How do I get the type of a variable?

#include <typeinfo>

...
string s = typeid(YourClass).name()

Smooth GPS data

This might come a little late...

I wrote this KalmanLocationManager for Android, which wraps the two most common location providers, Network and GPS, kalman-filters the data, and delivers updates to a LocationListener (like the two 'real' providers).

I use it mostly to "interpolate" between readings - to receive updates (position predictions) every 100 millis for instance (instead of the maximum gps rate of one second), which gives me a better frame rate when animating my position.

Actually, it uses three kalman filters, on for each dimension: latitude, longitude and altitude. They're independent, anyway.

This makes the matrix math much easier: instead of using one 6x6 state transition matrix, I use 3 different 2x2 matrices. Actually in the code, I don't use matrices at all. Solved all equations and all values are primitives (double).

The source code is working, and there's a demo activity. Sorry for the lack of javadoc in some places, I'll catch up.

Jquery split function

Javascript String objects have a split function, doesn't really need to be jQuery specific

 var str = "nice.test"
 var strs = str.split(".")

strs would be

 ["nice", "test"]

I'd be tempted to use JSON in your example though. The php could return the JSON which could easily be parsed

 success: function(data) {
   var items = JSON.parse(data)
 }

How do I force git pull to overwrite everything on every pull?

If you haven't commit the local changes yet since the last pull/clone, you can use:

git checkout *
git pull

checkout will clear your local changes with the last local commit, and pull will sincronize it to the remote repository

How can I provide multiple conditions for data trigger in WPF?

To elaborate on @serine's answer and illustrate working with non-trivial multi-valued condition: I had a need to show a "dim-out" overlay on an item for the boolean condition NOT a AND (b OR NOT c).

For background, this is a "Multiple Choice" question. If the user picks a wrong answer it becomes disabled (dimmed out and cannot be selected again). An automated agent has the ability to focus on any particular choice to give an explanation (border highlighted). When the agent focuses on an item, it should not be dimmed out even if it is disabled. All items that are not in focused are marked de-focused, and should be dimmed out.

The logic for dimming is thus:

NOT IsFocused AND (IsDefocused OR NOT Enabled)

To implement this logic, I made a generic IMultiValueConverter named (awkwardly) to match my logic

// 'P' represents a parenthesis
//     !  a &&  ( b ||  !  c )
class NOT_a_AND_P_b_OR_NOT_c_P : IMultiValueConverter
{
    // redacted [...] for brevity
    public object Convert(object[] values, ...)
    {
        bool a = System.Convert.ToBoolean(values[0]);
        bool b = System.Convert.ToBoolean(values[1]);
        bool c = System.Convert.ToBoolean(values[2]);

        return !a && (b || !c);
    }
    ...
}

In the XAML I use this in a MultiDataTrigger in a <Style><Style.Triggers> resource

<MultiDataTrigger>
    <MultiDataTrigger.Conditions>
        <!-- when the equation is TRUE ... -->
        <Condition Value="True">
            <Condition.Binding>
                <MultiBinding Converter="{StaticResource NOT_a_AND_P_b_OR_NOT_c_P}">
                    <!-- NOT IsFocus AND ( IsDefocused OR NOT Enabled ) -->
                    <Binding Path="IsFocus"/>
                    <Binding Path="IsDefocused" />
                    <Binding Path="Enabled" />
                </MultiBinding>
            </Condition.Binding>
        </Condition>
    </MultiDataTrigger.Conditions>
    <MultiDataTrigger.Setters>
        <!-- ... show the 'dim-out' overlay -->
        <Setter Property="Visibility" Value="Visible" />
    </MultiDataTrigger.Setters>
</MultiDataTrigger>

And for completeness sake, my converter is defined in a ResourceDictionary

<ResourceDictionary xmlns:conv="clr-namespace:My.Converters" ...>
    <conv:NOT_a_AND_P_b_OR_NOT_c_P x:Key="NOT_a_AND_P_b_OR_NOT_c_P" />
</ResourceDictionary>

How to change collation of database, table, column?

Better variant to generate SQL script by SQL request. It will not ruin defaults/nulls.

SELECT concat
    (
        'ALTER TABLE ', 
            t1.TABLE_SCHEMA, 
            '.', 
            t1.table_name, 
            ' MODIFY ', 
            t1.column_name, 
            ' ', 
            t1.column_type,
            ' CHARACTER SET utf8 COLLATE utf8_general_ci',
            if(t1.is_nullable='YES', ' NULL', ' NOT NULL'),
            if(t1.column_default is not null, concat(' DEFAULT \'', t1.column_default, '\''), ''),
            ';'
    )
from 
    information_schema.columns t1
where 
    t1.TABLE_SCHEMA like 'your_table_here' AND
    t1.COLLATION_NAME IS NOT NULL AND
    t1.COLLATION_NAME NOT IN ('utf8_general_ci');

Bold words in a string of strings.xml in Android

strings.xml

<string name="sentence">This price is <b>%1$s</b> USD</string>

page.java

String successMessage = getText(R.string.message,"5.21");

This price 5.21 USD

How to read the last row with SQL Server

SELECT * from Employees where [Employee ID] = ALL (SELECT MAX([Employee ID]) from Employees)

How do I create a local database inside of Microsoft SQL Server 2014?

Warning! SQL Server 14 Express, SQL Server Management Studio, and SQL 2014 LocalDB are separate downloads, make sure you actually installed SQL Server and not just the Management Studio! SQL Server 14 express with LocalDB download link

Youtube video about entire process.
Writeup with pictures about installing SQL Server

How to select a local server:

When you are asked to connect to a 'database server' right when you open up SQL Server Management Studio do this:

1) Make sure you have Server Type: Database

2) Make sure you have Authentication: Windows Authentication (no username & password)

3) For the server name field look to the right and select the drop down arrow, click 'browse for more'

4) New window pops up 'Browse for Servers', make sure to pick 'Local Servers' tab and under 'Database Engine' you will have the local server you set up during installation of SQL Server 14

How do I create a local database inside of Microsoft SQL Server 2014?

1) After you have connected to a server, bring up the Object Explorer toolbar under 'View' (Should open by default)

2) Now simply right click on 'Databases' and then 'Create new Database' to be taken through the database creation tools!

Reading a key from the Web.Config using ConfigurationManager

Try using the WebConfigurationManager class instead. For example:

string userName = WebConfigurationManager.AppSettings["PFUserName"]

How to get all the AD groups for a particular user?

This code works even faster (two 1.5 faster than my previous version):

    public List<String> GetUserGroups(WindowsIdentity identity)
    {
        List<String> groups = new List<String>();

        String userName = identity.Name;
        int pos = userName.IndexOf(@"\");
        if (pos > 0) userName = userName.Substring(pos + 1);

        PrincipalContext domain = new PrincipalContext(ContextType.Domain, "riomc.com");
        UserPrincipal user = UserPrincipal.FindByIdentity(domain, IdentityType.SamAccountName, userName); // NGeodakov

        DirectoryEntry de = new DirectoryEntry("LDAP://RIOMC.com");
        DirectorySearcher search = new DirectorySearcher(de);
        search.Filter = "(&(objectClass=group)(member=" + user.DistinguishedName + "))";
        search.PropertiesToLoad.Add("cn");
        search.PropertiesToLoad.Add("samaccountname");
        search.PropertiesToLoad.Add("memberOf");

        SearchResultCollection results = search.FindAll();
        foreach (SearchResult sr in results)
        {
            GetUserGroupsRecursive(groups, sr, de);
        }

        return groups;
    }

    public void GetUserGroupsRecursive(List<String> groups, SearchResult sr, DirectoryEntry de)
    {
        if (sr == null) return;

        String group = (String)sr.Properties["cn"][0];
        if (String.IsNullOrEmpty(group))
        {
            group = (String)sr.Properties["samaccountname"][0];
        }
        if (!groups.Contains(group))
        {
            groups.Add(group);
        }

        DirectorySearcher search;
        SearchResult sr1;
        String name;
        int equalsIndex, commaIndex;
        foreach (String dn in sr.Properties["memberof"])
        {
            equalsIndex = dn.IndexOf("=", 1);
            if (equalsIndex > 0)
            {
                commaIndex = dn.IndexOf(",", equalsIndex + 1);
                name = dn.Substring(equalsIndex + 1, commaIndex - equalsIndex - 1);

                search = new DirectorySearcher(de);
                search.Filter = "(&(objectClass=group)(|(cn=" + name + ")(samaccountname=" + name + ")))";
                search.PropertiesToLoad.Add("cn");
                search.PropertiesToLoad.Add("samaccountname");
                search.PropertiesToLoad.Add("memberOf");
                sr1 = search.FindOne();
                GetUserGroupsRecursive(groups, sr1, de);
            }
        }
    }

Can't specify the 'async' modifier on the 'Main' method of a console app

Newest version of C# - C# 7.1 allows to create async console app. To enable C# 7.1 in project, you have to upgrade your VS to at least 15.3, and change C# version to C# 7.1 or C# latest minor version. To do this, go to Project properties -> Build -> Advanced -> Language version.

After this, following code will work:

internal class Program
{
    public static async Task Main(string[] args)
    {
         (...)
    }

HTML/CSS: Making two floating divs the same height

You can get equal height columns in CSS by applying bottom padding of a large amount, bottom negative margin of the same amount and surrounding the columns with a div that has overflow hidden. Vertically centering the text is a little trickier but this should help you on the way.

_x000D_
_x000D_
#container {_x000D_
  overflow: hidden;_x000D_
      width: 100%;_x000D_
}_x000D_
#left-col {_x000D_
  float: left;_x000D_
  width: 50%;_x000D_
  background-color: orange;_x000D_
  padding-bottom: 500em;_x000D_
  margin-bottom: -500em;_x000D_
}_x000D_
#right-col {_x000D_
  float: left;_x000D_
  width: 50%;_x000D_
  margin-right: -1px; /* Thank you IE */_x000D_
  border-left: 1px solid black;_x000D_
  background-color: red;_x000D_
  padding-bottom: 500em;_x000D_
  margin-bottom: -500em;_x000D_
}
_x000D_
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"_x000D_
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">_x000D_
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">_x000D_
_x000D_
<head></head>_x000D_
_x000D_
<body>_x000D_
  <div id="container">_x000D_
    <div id="left-col">_x000D_
      <p>Test content</p>_x000D_
      <p>longer</p>_x000D_
    </div>_x000D_
    <div id="right-col">_x000D_
      <p>Test content</p>_x000D_
    </div>_x000D_
  </div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

I think it worth mentioning that the previous answer by streetpc has invalid html, the doctype is XHTML and there are single quotes around the attributes. Also worth noting is that you dont need an extra element with clear on in order to clear the internal floats of the container. If you use overflow hidden this clears the floats in all non-IE browsers and then just adding something to give hasLayout such as width or zoom:1 will cause IE to clear its internal floats.

I have tested this in all modern browsers FF3+ Opera9+ Chrome Safari 3+ and IE6/7/8. It may seem like an ugly trick but it works well and I use it in production a lot.

I hope this helps.

How to get the Full file path from URI

I had a hard time trying to figure this out on Xamarin. From the suggestions above I came up with this solution.

private string getRealPathFromURI(Android.Net.Uri contentUri)
{
    string filename = "";
    string thepath = "";
    Android.Net.Uri filePathUri;
    ICursor cursor = this.ContentResolver.Query(contentUri, null, null, null, null);

    if (cursor.MoveToFirst())
    {
        int column_index = cursor.GetColumnIndex(MediaStore.Images.Media.InterfaceConsts.Data);//Instead of "MediaStore.Images.Media.DATA" can be used "_data"
        filePathUri = Android.Net.Uri.Parse(cursor.GetString(column_index));
        filename = filePathUri.LastPathSegment;
        thepath = filePathUri.Path;
    }

    return thepath;
}

How do I remove files saying "old mode 100755 new mode 100644" from unstaged changes in Git?

The accepted answer to set git config core.filemode false, works, but with consequences. Setting core.filemode to false tells git to ignore any executable bit changes on the filesystem so it won't view this as a change. If you do need to stage an executable bit change for this repository anytime in the future, you would have to do it manually, or set core.filemode back to true.

A less consequential alternative, if all the modified files should have mode 100755, is to do something like

chmod 100755 $(git ls-files --modified)

which just does exactly the change in mode, no more, no less, without additional implications.

(in my case, it was due to a OneDrive sync with my filesystem on MacOS; by not changing core.filemode, I'm leaving the possibility open that the mode change might happen again in the future; in my case, I'd like to know if it happens again, and changing core.filemode will hide it from me, which I don't want)

Setting HttpContext.Current.Session in a unit test

Try this way..

public static HttpContext getCurrentSession()
  {
        HttpContext.Current = new HttpContext(new HttpRequest("", ConfigurationManager.AppSettings["UnitTestSessionURL"], ""), new HttpResponse(new System.IO.StringWriter()));
        System.Web.SessionState.SessionStateUtility.AddHttpSessionStateToContext(
        HttpContext.Current, new HttpSessionStateContainer("", new SessionStateItemCollection(), new HttpStaticObjectsCollection(), 20000, true,
        HttpCookieMode.UseCookies, SessionStateMode.InProc, false));
        return HttpContext.Current;
  }

How do I launch a program from command line without opening a new cmd window?

I think if you closed a program

taskkill /f /im "winamp.exe" 
//....(winamp.exe is example)...

end, so if you want to start a program that you can use

start "" /normal winamp.exe 

(/norma,/max/min are that process value cpu)

ALSO

start "filepath"enter image description here

if you want command line without openning an new window you write that

start /b "filepath"enter image description here

/B is Start application without creating a new window. The application has ^C handling ignored. Unless the application enables ^C processing, ^Break is the only way to interrupt the application.

Write a function that returns the longest palindrome in a given string

_x000D_
_x000D_
#longest palindrome_x000D_
s='HYTBCABADEFGHABCDEDCBAGHTFYW123456789987654321ZWETYGDE'_x000D_
out1=[]_x000D_
def substring(x):_x000D_
    for i in range(len(x)):_x000D_
        a=x[i:]_x000D_
        b=x[:-i]_x000D_
        out1.append(a)_x000D_
        out1.append(b)_x000D_
        _x000D_
    return out1_x000D_
_x000D_
for i in range(len(s)):_x000D_
    substring(s[i:])    _x000D_
final=set([item for item in out1 if len(item)>2])_x000D_
final_x000D_
palind={item:len(item) for item in final if item==item[::-1]}_x000D_
print(palind)_x000D_
sorted(palind.items(),reverse=True, key=lambda x: x[1])[0]
_x000D_
_x000D_
_x000D_

{'DED': 3, '123456789987654321': 18, '67899876': 8, 'ABCDEDCBA': 9, '456789987654': 12, '34567899876543': 14, 'BCDEDCB': 7, 'ABA': 3, '5678998765': 10, '2345678998765432': 16, 'CDEDC': 5, '789987': 6, '8998': 4} ('123456789987654321', 18)

How to Calculate Execution Time of a Code Snippet in C++

Thats how i do it, not much code, easy to understand, fits my needs:

void bench(std::function<void()> fnBench, std::string name, size_t iterations)
{
    if (iterations == 0)
        return;
    if (fnBench == nullptr)
        return;
    std::chrono::high_resolution_clock::time_point start, end;
    if (iterations == 1)
    {
        start = std::chrono::high_resolution_clock::now();
        fnBench();
        end = std::chrono::high_resolution_clock::now();
    }
    else
    {
        start = std::chrono::high_resolution_clock::now();
        for (size_t i = 0; i < iterations; ++i)
            fnBench();
        end = std::chrono::high_resolution_clock::now();
    }
    printf
    (
        "bench(*, \"%s\", %u) = %4.6lfs\r\n",
        name.c_str(),
        iterations,
        std::chrono::duration_cast<std::chrono::duration<double>>(end - start).count()
    );
}

Usage:

bench
(
    []() -> void // function
    {
        // Put your code here
    },
    "the name of this", // name
    1000000 // iterations
);

Is Unit Testing worth the effort?

Who are you trying to convince? Engineers or manager? If you are trying to convince your engineer co-workers I think your best bet is to appeal to their desire to make a high quality piece of software. There are numerous studies that show it finds bugs, and if they care about doing a good job, that should be enough for them.

If you are trying to convince management, you will most likely have to do some kind of cost/benefit reasoning saying that the cost of the defects that will be undetected is greater than the cost of writing the tests. Be sure to include intagable costs too, such as loss of customer confidence, etc.

Difference between onLoad and ng-init in angular

From angular's documentation,

ng-init SHOULD NOT be used for any initialization. It should be used only for aliasing. https://docs.angularjs.org/api/ng/directive/ngInit

onload should be used if any expression needs to be evaluated after a partial view is loaded (by ng-include). https://docs.angularjs.org/api/ng/directive/ngInclude

The major difference between them is when used with ng-include.

<div ng-include="partialViewUrl" onload="myFunction()"></div>

In this case, myFunction is called everytime the partial view is loaded.

<div ng-include="partialViewUrl" ng-init="myFunction()"></div>

Whereas, in this case, myFunction is called only once when the parent view is loaded.

Getting a HeadlessException: No X11 DISPLAY variable was set

I assume you're trying to tunnel into some unix box.

Make sure X11 forwarding is enabled in your PuTTY settings.

enter image description here

JavaScript module pattern with example

Here https://toddmotto.com/mastering-the-module-pattern you can find the pattern thoroughly explained. I would add that the second thing about modular JavaScript is how to structure your code in multiple files. Many folks may advice you here to go with AMD, yet I can say from experience that you will end up on some point with slow page response because of numerous HTTP requests. The way out is pre-compilation of your JavaScript modules (one per file) into a single file following CommonJS standard. Take a look at samples here http://dsheiko.github.io/cjsc/

Static Block in Java

A static block executes once in the life cycle of any program, another property of static block is that it executes before the main method.

Round a double to 2 decimal places

I think this is easier:

double time = 200.3456;
DecimalFormat df = new DecimalFormat("#.##");      
time = Double.valueOf(df.format(time));

System.out.println(time); // 200.35

Note that this will actually do the rounding for you, not just formatting.

How to shrink temp tablespace in oracle?

Oh My Goodness! Look at the size of my temporary table space! Or... how to shrink temporary tablespaces in Oracle.

Yes I ran a query to see how big my temporary tablespace is:

SQL> SELECT tablespace_name, file_name, bytes
2  FROM dba_temp_files WHERE tablespace_name like 'TEMP%';

TABLESPACE_NAME   FILE_NAME                                 BYTES
----------------- -------------------------------- --------------
TEMP              /the/full/path/to/temp01.dbf     13,917,200,000

The first question you have to ask is why the temporary tablespace is so large. You may know the answer to this off the top of your head. It may be due to a large query that you just run with a sort that was a mistake (I have done that more than once.) It may be due to some other exceptional circumstance. If that is the case then all you need to do to clean up is to shrink the temporary tablespace and move on in life.

But what if you don't know? Before you decide to shrink you may need to do some investigation into the causes of the large tablespace. If this happens on a regular basis then it is possible that your database just needs that much space.

The dynamic performance view

V$TEMPSEG_USAGE

can be very useful in determining the cause.

Maybe you just don't care about the cause and you just need to shrink it. This is your third day on the job. The data in the database is only 200MiB if data and the temporary tablespace is 13GiB - Just shrink it and move on. If it grows again then we will look into the cause. In the mean time I am out of space on that disk volume and I just need the space back.

Let's take a look at shrinking it. It will depend a little on what version of Oracle you are running and how the temporary tablespace was set up.
Oracle will do it's best to keep you from making any horrendous mistakes so we will just try the commands and if they don't work we will shrink in a new way.

First let's try to shrink the datafile. If we can do that then we get back the space and we can worry about why it grew tomorrow.

SQL>
SQL> alter database tempfile '/the/full/path/to/temp01.dbf' resize 256M; 
alter database tempfile '/the/full/path/to/temp01.dbf' resize 256M
*   
ERROR at line 1:
ORA-03297: file contains used data beyond requested RESIZE value

Depending on the error message you may want to try this with different sizes that are smaller than the current site of the file. I have had limited success with this. Oracle will only shrink the file if the temporary tablespace is at the head of the file and if it is smaller than the size you specify. Some old Oracle documentation (they corrected this) said that you could issue the command and the error message would tell you what size you could shrink to. By the time I started working as a DBA this was not true. You just had to guess and re-run the command a bunch of times and see if it worked.

Alright. That didn't work. How about this.

SQL> alter tablespace YOUR_TEMP_TABLESPACE_NAME shrink space keep 256M;

If you are in 11g (Maybee in 10g too) this is it! If it works you may want to go back to the previous command and give it some more tries.

But what if that fails. If the temporary tablespace is the default temporary that was set up when the database was installed then you may need to do a lot more work. At this point I usually re-evaluate if I really need that space back. After all disk space only costs $X.XX a GiB. Usually I don't want to make changes like this during production hours. That means working at 2AM AGAIN! (Not that I really object to working at 2AM - it is just that... Well I like to sleep too. And my wife likes to have me at home at 2AM... not roaming the downtown streets at 4AM trying to remember where I parked my car 3 hours earlier. I have heard of that "telecommuting" thing. I just worry that I will get half way through and then my internet connectivity will fail - then I have to rush downtown to fix it all before folks show up in the morning to use the database.)

Ok... Back to the serious stuff... If the temporary tablespace you want to shrink is your default temporary tablespace, you will have to first create a new temporary tablespace, set it as the default temporary tablespace then drop your old default temporary tablespace and recreate it. Afterwords drop the second temporary table created.

SQL> CREATE TEMPORARY TABLESPACE temp2
2  TEMPFILE '/the/full/path/to/temp2_01.dbf' SIZE 5M REUSE
3  AUTOEXTEND ON NEXT 1M MAXSIZE unlimited
4  EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M;

Tablespace created.

SQL> ALTER DATABASE DEFAULT TEMPORARY TABLESPACE temp2;

Database altered.

SQL> DROP TABLESPACE temp INCLUDING CONTENTS AND DATAFILES;

Tablespace dropped.


SQL> CREATE TEMPORARY TABLESPACE temp
2  TEMPFILE '/the/full/path/to/temp01.dbf' SIZE 256M REUSE
3  AUTOEXTEND ON NEXT 128M MAXSIZE unlimited
4  EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M;

Tablespace created.

SQL> ALTER DATABASE DEFAULT TEMPORARY TABLESPACE temp;

Database altered.

SQL> DROP TABLESPACE temp2 INCLUDING CONTENTS AND DATAFILES;

Tablespace dropped.

Hopefully one of these things will help!

How to replace <span style="font-weight: bold;">foo</span> by <strong>foo</strong> using PHP and regex?

$text='<span style="font-weight: bold;">Foo</span>';
$text=preg_replace( '/<span style="font-weight: bold;">(.*?)<\/span>/', '<strong>$1</strong>',$text);

Note: only work for your example.

Equivalent of LIMIT and OFFSET for SQL Server?

Since, I test more times this script more useful by 1 million records each page 100 records with pagination work faster my PC execute this script 0 sec while compare with mysql have own limit and offset about 4.5 sec to get the result.

Someone may miss understanding Row_Number() always sort by specific field. In case we need to define only row in sequence should use:

ROW_NUMBER() OVER (ORDER BY (SELECT NULL))

SELECT TOP {LIMIT} * FROM (
      SELECT TOP {LIMIT} + {OFFSET} ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS ROW_NO,*
      FROM  {TABLE_NAME}
) XX WHERE ROW_NO > {OFFSET}

Explain:

  • {LIMIT}: Number of records for each page
  • {OFFSET}: Number of skip records

Count number of occurences for each unique value

length(unique(df$col)) is the most simple way I can see.

Effective swapping of elements of an array in Java

public class SwapElements {

public static void main(String[] args) {

    int[] arr1 = new int[5];
    int[] arr2 = {10,20,30,40};

    System.out.println("arr1 Before Swapping " + Arrays.toString(arr1));
    System.out.println("arr2 Before Swapping " + Arrays.toString(arr2));

    int temp[];
    arr1[3] = 5;
    arr1[0] = 2;
    arr1[1] = 3;
    arr1[2] = 6;
    arr1[4] = 10;

    temp = arr1;
    arr1 = arr2;
    arr2 = temp;
    System.out.println("arr1 after Swapping " + Arrays.toString(arr1));
    System.out.println("arr2 after Swapping " + Arrays.toString(arr2));
}

}

JavaScript ES6 promise for loop

You can use async/await for this. I would explain more, but there's nothing really to it. It's just a regular for loop but I added the await keyword before the construction of your Promise

What I like about this is your Promise can resolve a normal value instead of having a side effect like your code (or other answers here) include. This gives you powers like in The Legend of Zelda: A Link to the Past where you can affect things in both the Light World and the Dark World – ie, you can easily work with data before/after the Promised data is available without having to resort to deeply nested functions, other unwieldy control structures, or stupid IIFEs.

// where DarkWorld is in the scary, unknown future
// where LightWorld is the world we saved from Ganondorf
LightWorld ... await DarkWorld

So here's what that will look like ...

_x000D_
_x000D_
const someProcedure = async n =>_x000D_
  {_x000D_
    for (let i = 0; i < n; i++) {_x000D_
      const t = Math.random() * 1000_x000D_
      const x = await new Promise(r => setTimeout(r, t, i))_x000D_
      console.log (i, x)_x000D_
    }_x000D_
    return 'done'_x000D_
  }_x000D_
_x000D_
someProcedure(10).then(x => console.log(x)) // => Promise_x000D_
// 0 0_x000D_
// 1 1_x000D_
// 2 2_x000D_
// 3 3_x000D_
// 4 4_x000D_
// 5 5_x000D_
// 6 6_x000D_
// 7 7_x000D_
// 8 8_x000D_
// 9 9_x000D_
// done
_x000D_
_x000D_
_x000D_

See how we don't have to deal with that bothersome .then call within our procedure? And async keyword will automatically ensure that a Promise is returned, so we can chain a .then call on the returned value. This sets us up for great success: run the sequence of n Promises, then do something important – like display a success/error message.

Remove all of x axis labels in ggplot

You have to set to element_blank() in theme() elements you need to remove

ggplot(data = diamonds, mapping = aes(x = clarity)) + geom_bar(aes(fill = cut))+
  theme(axis.title.x=element_blank(),
        axis.text.x=element_blank(),
        axis.ticks.x=element_blank())

How to select date without time in SQL

Use CAST(GETDATE() as date) that worked for me, simple.

How can I start PostgreSQL on Windows?

first find your binaries file where it is saved. get the path in terminal mine is

C:\Users\LENOVO\Documents\postgresql-9.5.21-1-windows-x64-binaries (1)\pgsql\bin

then find your local user data path, it is in mostly

C:\usr\local\pgsql\data

now all we have to hit following command in the binary terminal path:

C:\Users\LENOVO\Documents\postgresql-9.5.21-1-windows-x64-binaries (1)\pgsql\bin>pg_ctl -D "C:\usr\local\pgsql\data" start

all done!

autovaccum launcher started! cheers!

How to get a value from a Pandas DataFrame and not the index and object type

Use the values attribute to return the values as a np array and then use [0] to get the first value:

In [4]:
df.loc[df.Letters=='C','Letters'].values[0]

Out[4]:
'C'

EDIT

I personally prefer to access the columns using subscript operators:

df.loc[df['Letters'] == 'C', 'Letters'].values[0]

This avoids issues where the column names can have spaces or dashes - which mean that accessing using ..

How to save an HTML5 Canvas as an image on a server?

If you want to save data that is derived from a Javascript canvas.toDataURL() function, you have to convert blanks into plusses. If you do not do that, the decoded data is corrupted:

<?php
  $encodedData = str_replace(' ','+',$encodedData);
  $decocedData = base64_decode($encodedData);
?>

http://php.net/manual/ro/function.base64-decode.php

PHP - remove all non-numeric characters from a string

You can use preg_replace in this case;

$res = preg_replace("/[^0-9]/", "", "Every 6 Months" );

$res return 6 in this case.

If want also to include decimal separator or thousand separator check this example:

$res = preg_replace("/[^0-9.]/", "", "$ 123.099");

$res returns "123.099" in this case

Include period as decimal separator or thousand separator: "/[^0-9.]/"

Include coma as decimal separator or thousand separator: "/[^0-9,]/"

Include period and coma as decimal separator and thousand separator: "/[^0-9,.]/"

Querying data by joining two tables in two database on different servers

If the database link option is not available, another route you could take is to link the tables via ODBC to something such as MS Access or Crystal reports and do the join there.

Could not load file or assembly 'log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=692fbea5521e1304'

I tried all of that things and it doesn't worked for me.

I Just installed SAPCrystalReport in my computer and it's working now.

Multiple rows to one comma-separated value in Sql Server

Test Data

DECLARE @Table1 TABLE(ID INT, Value INT)
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400)

Query

SELECT  ID
       ,STUFF((SELECT ', ' + CAST(Value AS VARCHAR(10)) [text()]
         FROM @Table1 
         WHERE ID = t.ID
         FOR XML PATH(''), TYPE)
        .value('.','NVARCHAR(MAX)'),1,2,' ') List_Output
FROM @Table1 t
GROUP BY ID

Result Set

+--------------------------+
¦ ID ¦     List_Output     ¦
¦----+---------------------¦
¦  1 ¦  100, 200, 300, 400 ¦
+--------------------------+

SQL Server 2017 and Later Versions

If you are working on SQL Server 2017 or later versions, you can use built-in SQL Server Function STRING_AGG to create the comma delimited list:

DECLARE @Table1 TABLE(ID INT, Value INT);
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400);


SELECT ID , STRING_AGG([Value], ', ') AS List_Output
FROM @Table1
GROUP BY ID;

Result Set

+--------------------------+
¦ ID ¦     List_Output     ¦
¦----+---------------------¦
¦  1 ¦  100, 200, 300, 400 ¦
+--------------------------+

Fastest way to convert Image to Byte array

public static class HelperExtensions
{
    //Convert Image to byte[] array:
    public static byte[] ToByteArray(this Image imageIn)
    {
        var ms = new MemoryStream();
        imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
        return ms.ToArray();
    }

    //Convert byte[] array to Image:
    public static Image ToImage(this byte[] byteArrayIn)
    {
        var ms = new MemoryStream(byteArrayIn);
        var returnImage = Image.FromStream(ms);
        return returnImage;
    }
}

Java: JSON -> Protobuf & back conversion

For protobuf 2.5, use the dependency:

"com.googlecode.protobuf-java-format" % "protobuf-java-format" % "1.2"

Then use the code:

com.googlecode.protobuf.format.JsonFormat.merge(json, builder)
com.googlecode.protobuf.format.JsonFormat.printToString(proto)

Javascript: console.log to html

I come a bit late with a more advanced version of Arun P Johny's answer. His solution doesn't handle multiple console.log() arguments and doesn't give an access to the original function.

Here's my version:

_x000D_
_x000D_
(function (logger) {_x000D_
    console.old = console.log;_x000D_
    console.log = function () {_x000D_
        var output = "", arg, i;_x000D_
_x000D_
        for (i = 0; i < arguments.length; i++) {_x000D_
            arg = arguments[i];_x000D_
            output += "<span class=\"log-" + (typeof arg) + "\">";_x000D_
_x000D_
            if (_x000D_
                typeof arg === "object" &&_x000D_
                typeof JSON === "object" &&_x000D_
                typeof JSON.stringify === "function"_x000D_
            ) {_x000D_
                output += JSON.stringify(arg);   _x000D_
            } else {_x000D_
                output += arg;   _x000D_
            }_x000D_
_x000D_
            output += "</span>&nbsp;";_x000D_
        }_x000D_
_x000D_
        logger.innerHTML += output + "<br>";_x000D_
        console.old.apply(undefined, arguments);_x000D_
    };_x000D_
})(document.getElementById("logger"));_x000D_
_x000D_
// Testing_x000D_
console.log("Hi!", {a:3, b:6}, 42, true);_x000D_
console.log("Multiple", "arguments", "here");_x000D_
console.log(null, undefined);_x000D_
console.old("Eyy, that's the old and boring one.");
_x000D_
body {background: #333;}_x000D_
.log-boolean,_x000D_
.log-undefined {color: magenta;}_x000D_
.log-object,_x000D_
.log-string {color: orange;}_x000D_
.log-number {color: cyan;}
_x000D_
<pre id="logger"></pre>
_x000D_
_x000D_
_x000D_

I took it a tiny bit further and added a class to each log so you can color it. It outputs all arguments as seen in the Chrome console. You also have access to the old log via console.old().

Here's a minified version of the script above to paste inline, just for you:

<script>
    !function(o){console.old=console.log,console.log=function(){var n,e,t="";for(e=0;e<arguments.length;e++)t+='<span class="log-'+typeof(n=arguments[e])+'">',"object"==typeof n&&"object"==typeof JSON&&"function"==typeof JSON.stringify?t+=JSON.stringify(n):t+=n,t+="</span>&nbsp;";o.innerHTML+=t+"<br>",console.old.apply(void 0,arguments)}}
    (document.body);
</script>

Replace document.body in the parentheses with whatever element you wish to log into.

How to bind 'touchstart' and 'click' events but not respond to both?

This is the fix that I "create" and it take out the GhostClick and implements the FastClick. Try on your own and let us know if it worked for you.

$(document).on('touchstart click', '.myBtn', function(event){
        if(event.handled === false) return
        event.stopPropagation();
        event.preventDefault();
        event.handled = true;

        // Do your magic here

});

How do you push just a single Git branch (and no other branches)?

By default git push updates all the remote branches. But you can configure git to update only the current branch to it's upstream.

git config push.default upstream

It means git will update only the current (checked out) branch when you do git push.

Other valid options are:

  • nothing : Do not push anything (error out) unless a refspec is explicitly given. This is primarily meant for people who want to avoid mistakes by always being explicit.
  • matching : Push all branches having the same name on both ends. (default option prior to Ver 1.7.11)
  • upstream: Push the current branch to its upstream branch. This mode only makes sense if you are pushing to the same repository you would normally pull from (i.e. central workflow). No need to have the same name for local and remote branch.
  • tracking : Deprecated, use upstream instead.
  • current : Push the current branch to the remote branch of the same name on the receiving end. Works in both central and non-central workflows.
  • simple : [available since Ver 1.7.11] in centralized workflow, work like upstream with an added safety to refuse to push if the upstream branch’s name is different from the local one. When pushing to a remote that is different from the remote you normally pull from, work as current. This is the safest option and is suited for beginners. This mode has become the default in Git 2.0.

PostgreSQL error 'Could not connect to server: No such file or directory'

I don't really know Mac or Homebrew, but I know PostgreSQL very well.

You want to figure out where the logs are from PostgreSQL trying to start and what the socket directory is for PostgreSQL. By default when you build PG, the socket directory is /tmp/. If you didn't change that when you built PG and then you started PG, you should be able to see a socket file in /tmp if you do: ls -al /tmp

The socket file starts with a ".", so you won't see it with the '-a' to ls.

If you don't see a socket there, and you don't see anything from ps awux | grep postgres, then PG is probably not running, or maybe it is and it's the OSX-installed one. What might be happening is that you might be getting a conflict on listening on port 5432 on localhost- use netstat -anp to see what, if anything, is listening on 5432. If a Mac OSX PG is already listening on that port then that might be the problem.

Hope that helps. I have heard that homebrew can make things a bit ugly and a lot of people I've talked to encourage using a VM instead.

When should an IllegalArgumentException be thrown?

When talking about "bad input", you should consider where the input is coming from.

Is the input entered by a user or another external system you don't control, you should expect the input to be invalid, and always validate it. It's perfectly ok to throw a checked exception in this case. Your application should 'recover' from this exception by providing an error message to the user.

If the input originates from your own system, e.g. your database, or some other parts of your application, you should be able to rely on it to be valid (it should have been validated before it got there). In this case it's perfectly ok to throw an unchecked exception like an IllegalArgumentException, which should not be caught (in general you should never catch unchecked exceptions). It is a programmer's error that the invalid value got there in the first place ;) You need to fix it.

How to get current url in view in asp.net core 1.0

public string BuildAbsolute(PathString path, QueryString query = default(QueryString), FragmentString fragment = default(FragmentString))
{
    var rq = httpContext.Request;
    return Microsoft.AspNetCore.Http.Extensions.UriHelper.BuildAbsolute(rq.Scheme, rq.Host, rq.PathBase, path, query, fragment);
}

Calling the base constructor in C#

Modify your constructor to the following so that it calls the base class constructor properly:

public class MyExceptionClass : Exception
{
    public MyExceptionClass(string message, string extrainfo) : base(message)
    {
        //other stuff here
    }
}

Note that a constructor is not something that you can call anytime within a method. That's the reason you're getting errors in your call in the constructor body.

How can I use numpy.correlate to do autocorrelation?

I think there are 2 things that add confusion to this topic:

  1. statistical v.s. signal processing definition: as others have pointed out, in statistics we normalize auto-correlation into [-1,1].
  2. partial v.s. non-partial mean/variance: when the timeseries shifts at a lag>0, their overlap size will always < original length. Do we use the mean and std of the original (non-partial), or always compute a new mean and std using the ever changing overlap (partial) makes a difference. (There's probably a formal term for this, but I'm gonna use "partial" for now).

I've created 5 functions that compute auto-correlation of a 1d array, with partial v.s. non-partial distinctions. Some use formula from statistics, some use correlate in the signal processing sense, which can also be done via FFT. But all results are auto-correlations in the statistics definition, so they illustrate how they are linked to each other. Code below:

import numpy
import matplotlib.pyplot as plt

def autocorr1(x,lags):
    '''numpy.corrcoef, partial'''

    corr=[1. if l==0 else numpy.corrcoef(x[l:],x[:-l])[0][1] for l in lags]
    return numpy.array(corr)

def autocorr2(x,lags):
    '''manualy compute, non partial'''

    mean=numpy.mean(x)
    var=numpy.var(x)
    xp=x-mean
    corr=[1. if l==0 else numpy.sum(xp[l:]*xp[:-l])/len(x)/var for l in lags]

    return numpy.array(corr)

def autocorr3(x,lags):
    '''fft, pad 0s, non partial'''

    n=len(x)
    # pad 0s to 2n-1
    ext_size=2*n-1
    # nearest power of 2
    fsize=2**numpy.ceil(numpy.log2(ext_size)).astype('int')

    xp=x-numpy.mean(x)
    var=numpy.var(x)

    # do fft and ifft
    cf=numpy.fft.fft(xp,fsize)
    sf=cf.conjugate()*cf
    corr=numpy.fft.ifft(sf).real
    corr=corr/var/n

    return corr[:len(lags)]

def autocorr4(x,lags):
    '''fft, don't pad 0s, non partial'''
    mean=x.mean()
    var=numpy.var(x)
    xp=x-mean

    cf=numpy.fft.fft(xp)
    sf=cf.conjugate()*cf
    corr=numpy.fft.ifft(sf).real/var/len(x)

    return corr[:len(lags)]

def autocorr5(x,lags):
    '''numpy.correlate, non partial'''
    mean=x.mean()
    var=numpy.var(x)
    xp=x-mean
    corr=numpy.correlate(xp,xp,'full')[len(x)-1:]/var/len(x)

    return corr[:len(lags)]


if __name__=='__main__':

    y=[28,28,26,19,16,24,26,24,24,29,29,27,31,26,38,23,13,14,28,19,19,\
            17,22,2,4,5,7,8,14,14,23]
    y=numpy.array(y).astype('float')

    lags=range(15)
    fig,ax=plt.subplots()

    for funcii, labelii in zip([autocorr1, autocorr2, autocorr3, autocorr4,
        autocorr5], ['np.corrcoef, partial', 'manual, non-partial',
            'fft, pad 0s, non-partial', 'fft, no padding, non-partial',
            'np.correlate, non-partial']):

        cii=funcii(y,lags)
        print(labelii)
        print(cii)
        ax.plot(lags,cii,label=labelii)

    ax.set_xlabel('lag')
    ax.set_ylabel('correlation coefficient')
    ax.legend()
    plt.show()

Here is the output figure:

enter image description here

We don't see all 5 lines because 3 of them overlap (at the purple). The overlaps are all non-partial auto-correlations. This is because computations from the signal processing methods (np.correlate, FFT) don't compute a different mean/std for each overlap.

Also note that the fft, no padding, non-partial (red line) result is different, because it didn't pad the timeseries with 0s before doing FFT, so it's circular FFT. I can't explain in detail why, that's what I learned from elsewhere.

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

If you're using RStudio, please consider never using the rm(list = ls()) approach!* Instead, you should build your workflow around frequently employing the Ctrl+Shift+F10 shortcut to restart your R session. This is the fastest way to both nuke the current set of user-defined variables AND to clear loaded packages, devices, etc. The reproducibility of your work will increase markedly by adopting this habit.

See this excellent thread on Rstudio community for (h/t @kierisi) for a more thorough discussion (the main gist is captured by what I've stated already).

I must admit my own first few years of R coding featured script after script starting with the rm "trick" -- I'm writing this answer as advice to anyone else who may be starting out their R careers.

*of course there are legitimate uses for this -- much like attach -- but beginning users will be much better served (IMO) crossing that bridge at a later date.

Customize list item bullets using CSS

Based on @dzimney answer and similar to @Crisman answer (but different)

That answer is good but has indention problem (bullets appear inside of li scope). Probably you don't want this. See simple example list below (this is a default HTML list):

  • Lorem ipsum dolor sit amet, ei cum offendit partiendo iudicabit. At mei quaestio honestatis, duo dicit affert persecuti ei. Etiam nusquam cu his, nec alterum posidonium philosophia te. Nec an purto iudicabit, no vix quod clita expetendis.

  • Quem suscipiantur no eos, sed impedit explicari ea, falli inermis comprehensam est in. Vide dicunt ancillae cum te, habeo delenit deserunt mei in. Tale sint ex his, ipsum essent appellantur et cum.

But if you use the mentioned answer the list will be like below (ignoring the size of the bullets):

Lorem ipsum dolor sit amet, ei cum offendit partiendo iudicabit. At mei quaestio honestatis, duo dicit affert persecuti ei. Etiam nusquam cu his, nec alterum posidonium philosophia te. Nec an purto iudicabit, no vix quod clita expetendis.

Quem suscipiantur no eos, sed impedit explicari ea, falli inermis comprehensam est in. Vide dicunt ancillae cum te, habeo delenit deserunt mei in. Tale sint ex his, ipsum essent appellantur et cum.


So I recommend this approach that resolves the issue:

_x000D_
_x000D_
li {_x000D_
    list-style-type: none;_x000D_
    position: relative;    /* It's needed for setting position to absolute in the next rule. */_x000D_
}_x000D_
_x000D_
li::before {_x000D_
    content: '¦';_x000D_
    position: absolute;_x000D_
    left: -0.8em;          /* Adjust this value so that it appears where you want. */_x000D_
    font-size: 1.1em;      /* Adjust this value so that it appears what size you want. */_x000D_
}
_x000D_
<ul>_x000D_
    <li>Lorem ipsum dolor sit amet, ei cum offendit partiendo iudicabit. At mei quaestio honestatis, duo dicit affert persecuti ei. Etiam nusquam cu his, nec alterum posidonium philosophia te. Nec an purto iudicabit, no vix quod clita expetendis.</li>_x000D_
    <li>Quem suscipiantur no eos, sed impedit explicari ea, falli inermis comprehensam est in. Vide dicunt ancillae cum te, habeo delenit deserunt mei in. Tale sint ex his, ipsum essent appellantur et cum.</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

How do I force Kubernetes to re-pull an image?

My hack during development is to change my Deployment manifest to add the latest tag and always pull like so

image: etoews/my-image:latest
imagePullPolicy: Always

Then I delete the pod manually

kubectl delete pod my-app-3498980157-2zxhd

Because it's a Deployment, Kubernetes will automatically recreate the pod and pull the latest image.

Node.js Logging

Winston is a pretty good logging library. You can write logs out to a file using it.

Code would look something like:

var winston = require('winston');

var logger = new (winston.Logger)({
  transports: [
    new (winston.transports.Console)({ json: false, timestamp: true }),
    new winston.transports.File({ filename: __dirname + '/debug.log', json: false })
  ],
  exceptionHandlers: [
    new (winston.transports.Console)({ json: false, timestamp: true }),
    new winston.transports.File({ filename: __dirname + '/exceptions.log', json: false })
  ],
  exitOnError: false
});

module.exports = logger;

You can then use this like:

var logger = require('./log');

logger.info('log to file');

Where are my postgres *.conf files?

To get the location of the pg_hba.conf file, you can also query the database like

SHOW hba_file;

You should get something like

            hba_file             
---------------------------------
 /var/lib/pgsql/data/pg_hba.conf
(1 row)

What are pipe and tap methods in Angular tutorial?

You are right, the documentation lacks of those methods. However when I dug into rxjs repository, I found nice comments about tap (too long to paste here) and pipe operators:

  /**
   * Used to stitch together functional operators into a chain.
   * @method pipe
   * @return {Observable} the Observable result of all of the operators having
   * been called in the order they were passed in.
   *
   * @example
   *
   * import { map, filter, scan } from 'rxjs/operators';
   *
   * Rx.Observable.interval(1000)
   *   .pipe(
   *     filter(x => x % 2 === 0),
   *     map(x => x + x),
   *     scan((acc, x) => acc + x)
   *   )
   *   .subscribe(x => console.log(x))
   */

In brief:

Pipe: Used to stitch together functional operators into a chain. Before we could just do observable.filter().map().scan(), but since every RxJS operator is a standalone function rather than an Observable's method, we need pipe() to make a chain of those operators (see example above).

Tap: Can perform side effects with observed data but does not modify the stream in any way. Formerly called do(). You can think of it as if observable was an array over time, then tap() would be an equivalent to Array.forEach().

IIS Manager in Windows 10

  • Run appwiz.cpl - brings up Programs and Features
  • Choose "Turn Windows Features On/Off"
  • Select the IIS Services you need

CardView Corner Radius

An easy way to achieve this would be:

1.Make a custom background resource (like a rectangle shape) with rounded corners.

2.set this custom background using the command -

cardView = view.findViewById(R.id.card_view2);
cardView.setBackgroundResource(R.drawable.card_view_bg);

this worked for me.

The XML layout I made with top left and bottom right radius.

<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="@color/white" />
<corners android:topLeftRadius="18dp" android:bottomRightRadius="18dp" />
</shape>

In your case, you need to change only topLeftRadius as well as topRightRadius.

If you have a layout that overlaps with the corners of the card view and has a different color maybe, then you might need a different background resource file for the layout and in the xml set this background resource to your layout.

I tried and tested the above method. Hope this helps you.

github changes not staged for commit

WARNING! THIS WILL DELETE THE ENTIRE GIT HISTORY FOR YOUR SUBMODULE. ONLY DO THIS IF YOU CREATED THE SUBMODULE BY ACCIDENT. CERTAINLY NOT WHAT YOU WANT TO DO IN MOST CASES.

In my situation, there was a sub-directory which had a .git directory.

What I do is simply remove that .git directory from my sub-directory.

Create an ISO date object in javascript

This worked for me:

_x000D_
_x000D_
var start = new Date("2020-10-15T00:00:00.000+0000");
 //or
start = new date("2020-10-15T00:00:00.000Z");

collection.find({
    start_date:{
        $gte: start
    }
})...etc
_x000D_
_x000D_
_x000D_ new Date(2020,9,15,0,0,0,0) may lead to wrong date: i mean non ISO format (remember javascript count months from 0 to 11 so it's 9 for october)

How to scroll to specific item using jQuery?

For what it's worth, this is how I managed to achieve such behavior for a general element which can be inside a DIV with scrolling (without knowing the container)

It creates a fake input of the height of the target element, and then puts a focus to it, and the browser will take care about the rest no matter how deep within the scrollable hierarchy you are. Works like a charm.

var $scrollTo = $('#someId'),
inputElem = $('<input type="text"></input>');

$scrollTo.prepend(inputElem);
inputElem.css({
  position: 'absolute',
  width: '1px',
  height: $scrollTo.height()
});
inputElem.focus();
inputElem.remove();

List of encodings that Node.js supports

The encodings are spelled out in the buffer documentation.

Buffers and character encodings:

Character Encodings

  • utf8: Multi-byte encoded Unicode characters. Many web pages and other document formats use UTF-8. This is the default character encoding.
  • utf16le: Multi-byte encoded Unicode characters. Unlike utf8, each character in the string will be encoded using either 2 or 4 bytes.
  • latin1: Latin-1 stands for ISO-8859-1. This character encoding only supports the Unicode characters from U+0000 to U+00FF.

Binary-to-Text Encodings

  • base64: Base64 encoding. When creating a Buffer from a string, this encoding will also correctly accept "URL and Filename Safe Alphabet" as specified in RFC 4648, Section 5.
  • hex: Encode each byte as two hexadecimal characters.

Legacy Character Encodings

  • ascii: For 7-bit ASCII data only. Generally, there should be no reason to use this encoding, as 'utf8' (or, if the data is known to always be ASCII-only, 'latin1') will be a better choice when encoding or decoding ASCII-only text.
  • binary: Alias for 'latin1'.
  • ucs2: Alias of 'utf16le'.

How to get the last value of an ArrayList

If you use a LinkedList instead , you can access the first element and the last one with just getFirst() and getLast() (if you want a cleaner way than size() -1 and get(0))

Implementation

Declare a LinkedList

LinkedList<Object> mLinkedList = new LinkedList<>();

Then this are the methods you can use to get what you want, in this case we are talking about FIRST and LAST element of a list

/**
     * Returns the first element in this list.
     *
     * @return the first element in this list
     * @throws NoSuchElementException if this list is empty
     */
    public E getFirst() {
        final Node<E> f = first;
        if (f == null)
            throw new NoSuchElementException();
        return f.item;
    }

    /**
     * Returns the last element in this list.
     *
     * @return the last element in this list
     * @throws NoSuchElementException if this list is empty
     */
    public E getLast() {
        final Node<E> l = last;
        if (l == null)
            throw new NoSuchElementException();
        return l.item;
    }

    /**
     * Removes and returns the first element from this list.
     *
     * @return the first element from this list
     * @throws NoSuchElementException if this list is empty
     */
    public E removeFirst() {
        final Node<E> f = first;
        if (f == null)
            throw new NoSuchElementException();
        return unlinkFirst(f);
    }

    /**
     * Removes and returns the last element from this list.
     *
     * @return the last element from this list
     * @throws NoSuchElementException if this list is empty
     */
    public E removeLast() {
        final Node<E> l = last;
        if (l == null)
            throw new NoSuchElementException();
        return unlinkLast(l);
    }

    /**
     * Inserts the specified element at the beginning of this list.
     *
     * @param e the element to add
     */
    public void addFirst(E e) {
        linkFirst(e);
    }

    /**
     * Appends the specified element to the end of this list.
     *
     * <p>This method is equivalent to {@link #add}.
     *
     * @param e the element to add
     */
    public void addLast(E e) {
        linkLast(e);
    }

So , then you can use

mLinkedList.getLast(); 

to get the last element of the list.

Java: Finding the highest value in an array

An easy way without using collections

public void findHighestNoInArray() {
        int[] a = {1,2,6,8,9};
        int large = a[0];
            for(int num : a) {
                if(large < num) {
                    large = num;
                }
            }
            System.out.println("Large number is "+large+"");
        }

Open an html page in default browser with VBA?

I find the most simple is

shell "explorer.exe URL"

This also works to open local folders.

What is the unix command to see how much disk space there is and how much is remaining?

df -g .

Option g for Size in GBs Block and . for current working directory.

How to Scroll Down - JQuery

I mostly use following code to scroll down

$('html, body').animate({ scrollTop:  $(SELECTOR).offset().top - 50 }, 'slow');

C++ initial value of reference to non-const must be an lvalue

When you pass a pointer by a non-const reference, you are telling the compiler that you are going to modify that pointer's value. Your code does not do that, but the compiler thinks that it does, or plans to do it in the future.

To fix this error, either declare x constant

// This tells the compiler that you are not planning to modify the pointer
// passed by reference
void test(float * const &x){
    *x = 1000;
}

or make a variable to which you assign a pointer to nKByte before calling test:

float nKByte = 100.0;
// If "test()" decides to modify `x`, the modification will be reflected in nKBytePtr
float *nKBytePtr = &nKByte;
test(nKBytePtr);

nvm keeps "forgetting" node in new terminal session

This question has mentioned for the OSX, but it happened to me in my linux OS. I tried using nvm alias default <version> but for each new terminal session the used node version was forgotten. so, here is the solution that i figured out.

make sure to set a default alias for node version,put the following code in .bashrc, and source .bashrc.

export NVM_DIR="/home/bonnie/.nvm"
## If the file exists and is not empty
if [ -s "$NVM_DIR/nvm.sh" ]; then
    ## Source it
    source "$NVM_DIR/nvm.sh"
fi
NODE_DEFAULT_VERSION=$(<"$NVM_DIR/alias/default")
export PATH="$NVM_DIR/versions/node/$NODE_DEFAULT_VERSION/bin":$PATH

descriptive solution link

jQuery issue - #<an Object> has no method

Ignore me. I'm sorry everyone. I'd mistyped the url of the script. Thanks to Simon Ainley for the prod in the right direction.

Sorry again. Thanks.

Mercurial — revert back to old version and continue from there

I just encountered a case of needing to revert just one file to previous revision, right after I had done commit and push. Shorthand syntax for specifying these revisions isn't covered by the other answers, so here's command to do that

hg revert path/to/file -r-2

That -2 will revert to the version before last commit, using -1 would just revert current uncommitted changes.

SOAP vs REST (differences)

Among many others already covered in the many answers, I would highlight that SOAP enables to define a contract, the WSDL, which define the operations supported, complex types, etc. SOAP is oriented to operations, but REST is oriented at resources. Personally I would select SOAP for complex interfaces between internal enterprise applications, and REST for public, simpler, stateless interfaces with the outside world.

enter image description here

How to use Tomcat 8.5.x and TomEE 7.x with Eclipse?

You have to patch catalina.jar, as this is version number the WTP adapter looks at. It's a quite useless check, and the adapter should allow you to start the server anyway, but nobody has though of that yet.

For years and with every version of Tomcat this is always a problem.

To patch you can do the following:

  • cd [tomcat or tomee home]/lib
  • mkdir catalina
  • cd catalina/
  • unzip ../catalina.jar
  • vim org/apache/catalina/util/ServerInfo.properties

Make sure it looks like the following (the version numbers all need to start with 8.0):

server.info=Apache Tomcat/8.0.0
server.number=8.0.0
server.built=May 11 2016 21:49:07 UTC

Then:

  • jar uf ../catalina.jar org/apache/catalina/util/ServerInfo.properties
  • cd ..
  • rm -rf catalina

Examples of GoF Design Patterns in Java's core libraries

The Abstract Factory pattern is used in various places. E.g., DatagramSocketImplFactory, PreferencesFactory. There are many more---search the Javadoc for interfaces which have the word "Factory" in their name.

Also there are quite a few instances of the Factory pattern, too.

Run C++ in command prompt - Windows

Sure, it's how most compilers got started. GCC is probably the most popular (comes with most flavors of *nix). Syntax is just gcc my_source_code.cpp, or gcc -o my_executable.exe my_source_code.cpp. It gets more complicated, of course, when you have multiple source files (as in implementation; anything #included works automatically as long as GCC can find it).

MinGW appears to be a version of GCC for Windows, if that's what you're using. I haven't tried it though.

Pretty sure most IDEs also include a command line interface. I know Visual Studio does, though I have never used it.

get name of a variable or parameter

Alternatively,

1) Without touching System.Reflection namespace,

GETNAME(new { myInput });

public static string GETNAME<T>(T myInput) where T : class
{
    if (myInput == null)
        return string.Empty;

    return myInput.ToString().TrimStart('{').TrimEnd('}').Split('=')[0].Trim();
}

2) The below one can be faster though (from my tests)

GETNAME(new { variable });
public static string GETNAME<T>(T myInput) where T : class
{
    if (myInput == null)
        return string.Empty;

    return typeof(T).GetProperties()[0].Name;
}

You can also extend this for properties of objects (may be with extension methods):

new { myClass.MyProperty1 }.GETNAME();

You can cache property values to improve performance further as property names don't change during runtime.

The Expression approach is going to be slower for my taste. To get parameter name and value together in one go see this answer of mine

How to create a Java / Maven project that works in Visual Studio Code?

This is not a particularly good answer as it explains how to run your java code n VS Code and not necessarily a Maven project, but it worked for me because I could not get around to doing the manual configuration myself. I decided to use this method instead since it is easier and faster.

Install VSCode (and for windows, set your environment variables), then install vscode:extension/vscjava.vscode-java-pack as detailed above, and then install the code runner extension pack, which basically sets up the whole process (in the background) as explained in the accepted answer above and then provides a play button to run your java code when you're ready.

This was all explained in this video.

Again, this is not the best solution, but if you want to cut to the chase, you may find this answer useful.

Text border using css (border around text)

text-shadow: -1px 0 black, 0 1px black, 1px 0 black, 0 -1px black;

Extract the filename from a path

You can try this:

[System.IO.FileInfo]$path = "D:\Server\User\CUST\MEA\Data\In\Files\CORRECTED\CUST_MEAFile.csv"
# Returns name and extension
$path.Name
# Returns just name
$path.BaseName

String array initialization in Java

First up, this has got nothing to do with String, it is about arrays.. and that too specifically about declarative initialization of arrays.

As discussed by everyone in almost every answer here, you can, while declaring a variable, use:

String names[] = {"x","y","z"};

However, post declaration, if you want to assign an instance of an Array:

names = new String[] {"a","b","c"};

AFAIK, the declaration syntax is just a syntactic sugar and it is not applicable anymore when assigning values to variables because when values are assigned you need to create an instance properly.

However, if you ask us why it is so? Well... good luck getting an answer to that. Unless someone from the Java committee answers that or there is explicit documentation citing the said syntactic sugar.

GitLab remote: HTTP Basic: Access denied and fatal Authentication

Note: do not mix GitLab SSL settings and GitLab SSH keys.

If what you have configured in your GitLab profile is an SSH public key, then your HTTPS URL would not use it.

Regarding your HTTPS credentials, double-check:

  • if the two-factor authentication is disabled, or
  • if you have special characters in your username or password, or
  • if you have a Git credential helper: git config credential.helper.

Why can't I see the "Report Data" window when creating reports?

I was in a weird situation in VS2019 where choosing View -> Report Data did nothing, and pressing Ctrl-Alt-D did nothing. The Report Data window had just strangely appeared on the left for no reason, when it was supposed to be on the right, and so I had moved it back to the right and then made it auto-hide. Not long after that it disappeared and would refuse to reappear. Possibly it was off-screen but hard to say.

To fix, I had to resort to using Window -> Reset Window Layout which restored its position and I was able to use it again.

Laravel check if collection is empty

To determine if there are any results you can do any of the following:

if ($mentor->first()) { } 
if (!$mentor->isEmpty()) { }
if ($mentor->count()) { }
if (count($mentor)) { }
if ($mentor->isNotEmpty()) { }

Notes / References

->first()

https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Collection.html#method_first

isEmpty() https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Collection.html#method_isEmpty

->count()

https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Collection.html#method_count

count($mentors) works because the Collection implements Countable and an internal count() method:

https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Collection.html#method_count

isNotEmpty()

https://laravel.com/docs/5.7/collections#method-isnotempty

So what you can do is :

if (!$mentors->intern->employee->isEmpty()) { }

Changing a specific column name in pandas DataFrame

Following short code can help:

df3 = df3.rename(columns={c: c.replace(' ', '') for c in df3.columns})

Remove spaces from columns.

strdup() - what does it do in C?

The statement:

strcpy(ptr2, ptr1);

is equivalent to (other than the fact this changes the pointers):

while(*ptr2++ = *ptr1++);

Whereas:

ptr2 = strdup(ptr1);

is equivalent to:

ptr2 = malloc(strlen(ptr1) + 1);
if (ptr2 != NULL) strcpy(ptr2, ptr1);

So, if you want the string which you have copied to be used in another function (as it is created in heap section), you can use strdup, else strcpy is enough,

How do I change the background color of a plot made with ggplot2

Here's a custom theme to make the ggplot2 background white and a bunch of other changes that's good for publications and posters. Just tack on +mytheme. If you want to add or change options by +theme after +mytheme, it will just replace those options from +mytheme.

library(ggplot2)
library(cowplot)
theme_set(theme_cowplot())

mytheme = list(
    theme_classic()+
        theme(panel.background = element_blank(),strip.background = element_rect(colour=NA, fill=NA),panel.border = element_rect(fill = NA, color = "black"),
              legend.title = element_blank(),legend.position="bottom", strip.text = element_text(face="bold", size=9),
              axis.text=element_text(face="bold"),axis.title = element_text(face="bold"),plot.title = element_text(face = "bold", hjust = 0.5,size=13))
)

ggplot(data=data.frame(a=c(1,2,3), b=c(2,3,4)), aes(x=a, y=b)) + mytheme + geom_line()

custom ggplot theme

Get request URL in JSP which is forwarded by Servlet

To get the current path from within the JSP file you can simply do one of the following:

<%= request.getContextPath() %>
<%= request.getRequestURI() %>
<%= request.getRequestURL() %>

How to navigate through a vector using iterators? (C++)

Typically, iterators are used to access elements of a container in linear fashion; however, with "random access iterators", it is possible to access any element in the same fashion as operator[].

To access arbitrary elements in a vector vec, you can use the following:

vec.begin()                  // 1st
vec.begin()+1                // 2nd
// ...
vec.begin()+(i-1)            // ith
// ...
vec.begin()+(vec.size()-1)   // last

The following is an example of a typical access pattern (earlier versions of C++):

int sum = 0;
using Iter = std::vector<int>::const_iterator;
for (Iter it = vec.begin(); it!=vec.end(); ++it) {
    sum += *it;
}

The advantage of using iterator is that you can apply the same pattern with other containers:

sum = 0;
for (Iter it = lst.begin(); it!=lst.end(); ++it) {
    sum += *it;
}

For this reason, it is really easy to create template code that will work the same regardless of the container type. Another advantage of iterators is that it doesn't assume the data is resident in memory; for example, one could create a forward iterator that can read data from an input stream, or that simply generates data on the fly (e.g. a range or random number generator).

Another option using std::for_each and lambdas:

sum = 0;
std::for_each(vec.begin(), vec.end(), [&sum](int i) { sum += i; });

Since C++11 you can use auto to avoid specifying a very long, complicated type name of the iterator as seen before (or even more complex):

sum = 0;
for (auto it = vec.begin(); it!=vec.end(); ++it) {
    sum += *it;
}

And, in addition, there is a simpler for-each variant:

sum = 0;
for (auto value : vec) {
    sum += value;
}

And finally there is also std::accumulate where you have to be careful whether you are adding integer or floating point numbers.

How to display a database table on to the table in the JSP page

Tracking ID Track
    <br>
    <%String id = request.getParameter("track_id");%>
       <%if (id.length() == 0) {%>
    <b><h1>Please Enter Tracking ID</h1></b>
    <% } else {%>
    <div class="container">
        <table border="1" class="table" >
            <thead>
                <tr class="warning" >
                    <td ><h4>Track ID</h4></td>
                    <td><h4>Source</h4></td>
                    <td><h4>Destination</h4></td>
                    <td><h4>Current Status</h4></td>

                </tr>
            </thead>
            <%
                try {
                    connection = DriverManager.getConnection(connectionUrl + database, userid, password);
                    statement = connection.createStatement();
                    String sql = "select * from track where track_id="+ id;
                    resultSet = statement.executeQuery(sql);
                    while (resultSet.next()) {
            %>
            <tr class="info">
                <td><%=resultSet.getString("track_id")%></td>
                <td><%=resultSet.getString("source")%></td>
                <td><%=resultSet.getString("destination")%></td>
                <td><%=resultSet.getString("status")%></td>
            </tr>
            <%
                    }
                    connection.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            %>
        </table>

        <%}%>
</body>

How do I copy the contents of one stream to another?

The basic questions that differentiate implementations of "CopyStream" are:

  • size of the reading buffer
  • size of the writes
  • Can we use more than one thread (writing while we are reading).

The answers to these questions result in vastly different implementations of CopyStream and are dependent on what kind of streams you have and what you are trying to optimize. The "best" implementation would even need to know what specific hardware the streams were reading and writing to.

Drawable-hdpi, Drawable-mdpi, Drawable-ldpi Android

To declare different layouts and bitmaps you'd like to use for the different screens, you must place these alternative resources in separate directories/folders.

This means that if you generate a 200x200 image for xhdpi devices, you should generate the same resource in 150x150 for hdpi, 100x100 for mdpi, and 75x75 for ldpi devices.

Then, place the files in the appropriate drawable resource directory:

MyProject/
    res/
        drawable-xhdpi/
            awesomeimage.png
        drawable-hdpi/
            awesomeimage.png
        drawable-mdpi/
            awesomeimage.png
        drawable-ldpi/
            awesomeimage.png

Any time you reference @drawable/awesomeimage, the system selects the appropriate bitmap based on the screen's density.

Using PowerShell to write a file in UTF-8 without the BOM

Starting from version 6 powershell supports the UTF8NoBOM encoding both for set-content and out-file and even uses this as default encoding.

So in the above example it should simply be like this:

$MyFile | Out-File -Encoding UTF8NoBOM $MyPath

How to check the version of scipy

From the python command prompt:

import scipy
print scipy.__version__

In python 3 you'll need to change it to:

print (scipy.__version__)

Replacement for "rename" in dplyr

While not exactly renaming, dplyr::select_all() can be used to reformat column names. This example replaces spaces and periods with an underscore and converts everything to lower case:

iris %>%  
  select_all(~gsub("\\s+|\\.", "_", .)) %>% 
  select_all(tolower) %>% 
  head(2)
  sepal_length sepal_width petal_length petal_width species
1          5.1         3.5          1.4         0.2  setosa
2          4.9         3.0          1.4         0.2  setosa

go to character in vim

:goto 21490 will take you to the 21490th byte in the buffer.

Angular and Typescript: Can't find names - Error: cannot find name

For Angular 2.0.0-rc.0 adding node_modules/angular2/typings/browser.d.ts won't work. First add typings.json file to your solution, with this content:

{
    "ambientDependencies": {
        "es6-shim": "github:DefinitelyTyped/DefinitelyTyped/es6-shim/es6-shim.d.ts#7de6c3dd94feaeb21f20054b9f30d5dabc5efabd"
    }
}

And then update the package.json file to include this postinstall:

"scripts": {
    "postinstall": "typings install"
},

Now run npm install

Also now you should ignore typings folder in your tsconfig.json file as well:

 "exclude": [
        "node_modules",
        "typings/main",
        "typings/main.d.ts"
    ]

Update

Now AngularJS 2.0 is using core-js instead of es6-shim. Follow its quick start typings.json file for more info.

Stop absolutely positioned div from overlapping text

Short answer: There's no way to do it using CSS only.

Long(er) answer: Why? Because when you do position: absolute;, that takes your element out of the document's regular flow, so there's no way for the text to have any positional-relationship with it, unfortunately.

One of the possible alternatives is to float: right; your div, but if that doesn't achieve what you want, you'll have to use JavaScript/jQuery, or just come up with a better layout.

TensorFlow: "Attempting to use uninitialized value" in variable initialization

I want to give my resolution, it work when i replace the line [session = tf.Session()] with [sess = tf.InteractiveSession()]. Hope this will be useful to others.

Error: Unable to run mksdcard SDK tool

For Ubuntu, you can try:

sudo apt-get install lib32z1 lib32ncurses5 lib32bz2-1.0 lib32stdc++6

For Cent OS/RHEL try :

sudo yum install zlib.i686 ncurses-libs.i686 bzip2-libs.i686 

Then, re-install the Android Studio and get success.

How to print to console when using Qt

#include <QTextStream>
...
qDebug()<<"Bla bla bla";

Convert unsigned int to signed int C

To understand why, you need to know that the CPU represents signed numbers using the two's complement (maybe not all, but many).

    byte n = 1; //0000 0001 =  1
    n = ~n + 1; //1111 1110 + 0000 0001 = 1111 1111 = -1

And also, that the type int and unsigned int can be of different sized depending on your CPU. When doing specific stuff like this:

   #include <stdint.h>
   int8_t ibyte;
   uint8_t ubyte;
   int16_t iword;
   //......

How to clear all input fields in a specific div with jQuery?

inspired from https://stackoverflow.com/a/10892768/2087666 but I use the selector instead of a class and prefer if over switch:

function clearAllInputs(selector) {
  $(selector).find(':input').each(function() {
    if(this.type == 'submit'){
          //do nothing
      }
      else if(this.type == 'checkbox' || this.type == 'radio') {
        this.checked = false;
      }
      else if(this.type == 'file'){
        var control = $(this);
        control.replaceWith( control = control.clone( true ) );
      }else{
        $(this).val('');
      }
   });
}

this should take care of almost all input inside any selector.

How to measure elapsed time

From Java 8 onward you can try the following:

import java.time.*;
import java.time.temporal.ChronoUnit;

Instant start_time = Instant.now();
// Your code
Instant stop_time = Instant.now();

System.out.println(Duration.between(start_time, stop_time).toMillis());

//or

System.out.println(ChronoUnit.MILLIS.between(start_time, stop_time));

How to declare variable and use it in the same Oracle SQL script?

Just want to add Matas' answer. Maybe it's obvious, but I've searched for a long time to figure out that the variable is accessible only inside the BEGIN-END construction, so if you need to use it in some code later, you need to put this code inside the BEGIN-END block.

Note that these blocks can be nested:

DECLARE x NUMBER;
BEGIN
    SELECT PK INTO x FROM table1 WHERE col1 = 'test';

    DECLARE y NUMBER;
    BEGIN
        SELECT PK INTO y FROM table2 WHERE col2 = x;

        INSERT INTO table2 (col1, col2)
        SELECT y,'text'
        FROM dual
        WHERE exists(SELECT * FROM table2);

        COMMIT;
    END;
END;

What is managed or unmanaged code in programming?

Here is some text from MSDN about unmanaged code.

Some library code needs to call into unmanaged code (for example, native code APIs, such as Win32). Because this means going outside the security perimeter for managed code, due caution is required.

Here is some other complimentary explication about Managed code:

  • Code that is executed by the CLR.
  • Code that targets the common language runtime, the foundation of the .NET Framework, is known as managed code.
  • Managed code supplies the metadata necessary for the CLR to provide services such as memory management, cross-language integration, code access security, and automatic lifetime control of objects. All code based on IL executes as managed code.
  • Code that executes under the CLI execution environment.

For your problem:

I think it's because NUnit execute your code for UnitTesting and might have some part of it that is unmanaged. But I am not sure about it, so do not take this for gold. I am sure someone will be able to give you more information about it. Hope it helps!

Eclipse: Syntax Error, parameterized types are only if source level is 1.5

It can be resolved as follows:

Go to Project properties.

Then 'Java Compiler' -> Check the box ('Enable project specific settings')

Change the compiler compliance level to '5.0' & click ok

Select the checkbox for "Use default compliance settings"

How to add leading zeros for for-loop in shell?

why not printf '%02d' $num? See help printf for this internal bash command.

Converting a string to JSON object

You can use the JSON.parse() for that.

See docs at MDN

Example:

var myObj = JSON.parse('{"p": 5}');
console.log(myObj);

How does a ArrayList's contains() method evaluate objects?

The ArrayList uses the equals method implemented in the class (your case Thing class) to do the equals comparison.

How to execute an external program from within Node.js?

The simplest way is:

const { exec } = require("child_process")
exec('yourApp').unref()

unref is necessary to end your process without waiting for "yourApp"

Here are the exec docs

Variable declaration in a header file

What about this solution?

#ifndef VERSION_H
#define VERSION_H

static const char SVER[] = "14.2.1";
static const char AVER[] = "1.1.0.0";

#else

extern static const char SVER[];
extern static const char AVER[];

#endif /*VERSION_H */

The only draw back I see is that the include guard doesn't save you if you include it twice in the same file.

Splitting on first occurrence

From the docs:

str.split([sep[, maxsplit]])

Return a list of the words in the string, using sep as the delimiter string. If maxsplit is given, at most maxsplit splits are done (thus, the list will have at most maxsplit+1 elements).

s.split('mango', 1)[1]

javac is not recognized as an internal or external command, operable program or batch file

try this.. I had it too but now it solved in XP..

C:\ YourFolder >set path=C:\Program Files\Java\jdk1.7.0_09\bin;
C:\ YourFolder >javac YourCode.java

What is the difference between JSF, Servlet and JSP?

JSF is an advanced framework wherein its very easy to implement Model-View-Controller (MVC) based architecture for projects. Main advantage of JSF over JSP is the easy dynamic rendering of the components on the browser based upon conditions and easy integration of ajax events.

The front end of the JSF application i.e. xhtml files are the ones which are shown to the user via browser. These xhtml files internally invoke managed beans e.g. controllers wherein actual application logic is written.

The controllers internally invoke various services which communicate with database (using Hibernate or JPA API). This is how the flow happens in short.

JSF is also used in combination with RichFaces which is a framework for giving rich look and feel to your web application.

JSF + RichFaces + Hibernate/JPA is a good technology to learn for sure !

Placeholder Mixin SCSS/CSS

I use exactly the same sass mixin placeholder as NoDirection wrote. I find it in sass mixins collection here and I'm very satisfied with it. There's a text that explains a mixins option more.

Representational state transfer (REST) and Simple Object Access Protocol (SOAP)

Simple explanation about SOAP and REST

SOAP - "Simple Object Access Protocol"

SOAP is a method of transferring messages, or small amounts of information, over the Internet. SOAP messages are formatted in XML and are typically sent using HTTP (hypertext transfer protocol).


Rest - Representational state transfer

Rest is a simple way of sending and receiving data between client and server and it doesn't have very many standards defined. You can send and receive data as JSON, XML or even plain text. It's light weighted compared to SOAP.


enter image description here

Return a `struct` from a function in C

You can assign structs in C. a = b; is valid syntax.

You simply left off part of the type -- the struct tag -- in your line that doesn't work.

How can I remove a pytz timezone from a datetime object?

To remove a timezone (tzinfo) from a datetime object:

# dt_tz is a datetime.datetime object
dt = dt_tz.replace(tzinfo=None)

If you are using a library like arrow, then you can remove timezone by simply converting an arrow object to to a datetime object, then doing the same thing as the example above.

# <Arrow [2014-10-09T10:56:09.347444-07:00]>
arrowObj = arrow.get('2014-10-09T10:56:09.347444-07:00')

# datetime.datetime(2014, 10, 9, 10, 56, 9, 347444, tzinfo=tzoffset(None, -25200))
tmpDatetime = arrowObj.datetime

# datetime.datetime(2014, 10, 9, 10, 56, 9, 347444)
tmpDatetime = tmpDatetime.replace(tzinfo=None)

Why would you do this? One example is that mysql does not support timezones with its DATETIME type. So using ORM's like sqlalchemy will simply remove the timezone when you give it a datetime.datetime object to insert into the database. The solution is to convert your datetime.datetime object to UTC (so everything in your database is UTC since it can't specify timezone) then either insert it into the database (where the timezone is removed anyway) or remove it yourself. Also note that you cannot compare datetime.datetime objects where one is timezone aware and another is timezone naive.

##############################################################################
# MySQL example! where MySQL doesn't support timezones with its DATETIME type!
##############################################################################

arrowObj = arrow.get('2014-10-09T10:56:09.347444-07:00')

arrowDt = arrowObj.to("utc").datetime

# inserts datetime.datetime(2014, 10, 9, 17, 56, 9, 347444, tzinfo=tzutc())
insertIntoMysqlDatabase(arrowDt)

# returns datetime.datetime(2014, 10, 9, 17, 56, 9, 347444)
dbDatetimeNoTz = getFromMysqlDatabase()

# cannot compare timzeone aware and timezone naive
dbDatetimeNoTz == arrowDt # False, or TypeError on python versions before 3.3

# compare datetimes that are both aware or both naive work however
dbDatetimeNoTz == arrowDt.replace(tzinfo=None) # True

How Does Modulus Divison Work

Maybe the example with an clock could help you understand the modulo.

A familiar use of modular arithmetic is its use in the 12-hour clock, in which the day is divided into two 12 hour periods.

Lets say we have currently this time: 15:00
But you could also say it is 3 pm

This is exactly what modulo does:

15 / 12 = 1, remainder 3

You find this example better explained on wikipedia: Wikipedia Modulo Article

Loop through an array in JavaScript

The optimized approach is to cache the length of array and using the single variable pattern, initializing all variables with a single var keyword.

var i, max, myStringArray = ["Hello", "World"];
for (i = 0, max = myStringArray.length; i < max; i++) {
    alert(myStringArray[i]);

    // Do something
}

If the order of iteration does not matter then you should try reversed loop. It is the fastest as it reduces overhead condition testing and decrement is in one statement:

var i,myStringArray = ["item1","item2"];
for (i =  myStringArray.length; i--) {
    alert(myStringArray[i]);
}

Or better and cleaner to use a while loop:

var myStringArray = ["item1","item2"],i = myStringArray.length;
while(i--) {
   // Do something with fruits[i]
}

ImportError: No module named sklearn.cross_validation

It must relate to the renaming and deprecation of cross_validation sub-module to model_selection. Try substituting cross_validation to model_selection

What causes the error "undefined reference to (some function)"?

It's a linker error. ld is the linker, so if you get an error message ending with "ld returned 1 exit status", that tells you that it's a linker error.

The error message tells you that none of the object files you're linking against contains a definition for avergecolumns. The reason for that is that the function you've defined is called averagecolumns (in other words: you misspelled the function name when calling the function (and presumably in the header file as well - otherwise you'd have gotten a different error at compile time)).

In C#, can a class inherit from another class and an interface?

I found the answer to the second part of my questions. Yes, a class can implement an interface that is in a different class as long that the interface is declared as public.

How to push a new folder (containing other folders and files) to an existing git repo?

You need to git add my_project to stage your new folder. Then git add my_project/* to stage its contents. Then commit what you've staged using git commit and finally push your changes back to the source using git push origin master (I'm assuming you wish to push to the master branch).

Converting list to numpy array

If you have a list of lists, you only needed to use ...

import numpy as np
...
npa = np.asarray(someListOfLists, dtype=np.float32)

per this LINK in the scipy / numpy documentation. You just needed to define dtype inside the call to asarray.

Good examples using java.util.logging

There are many examples and also of different types for logging. Take a look at the java.util.logging package.

Example code:

import java.util.logging.Logger;

public class Main {

  private static Logger LOGGER = Logger.getLogger("InfoLogging");

  public static void main(String[] args) {
    LOGGER.info("Logging an INFO-level message");
  }
}

Without hard-coding the class name:

import java.util.logging.Logger;

public class Main {
  private static final Logger LOGGER = Logger.getLogger(
    Thread.currentThread().getStackTrace()[0].getClassName() );

  public static void main(String[] args) {
    LOGGER.info("Logging an INFO-level message");
  }
}

What are database normal forms and can you give examples?

1NF is the most basic of normal forms - each cell in a table must contain only one piece of information, and there can be no duplicate rows.

2NF and 3NF are all about being dependent on the primary key. Recall that a primary key can be made up of multiple columns. As Chris said in his response:

The data depends on the key [1NF], the whole key [2NF] and nothing but the key [3NF] (so help me Codd).

2NF

Say you have a table containing courses that are taken in a certain semester, and you have the following data:

|-----Primary Key----|               uh oh |
                                           V
CourseID | SemesterID | #Places  | Course Name  |
------------------------------------------------|
IT101    |   2009-1   | 100      | Programming  |
IT101    |   2009-2   | 100      | Programming  |
IT102    |   2009-1   | 200      | Databases    |
IT102    |   2010-1   | 150      | Databases    |
IT103    |   2009-2   | 120      | Web Design   |

This is not in 2NF, because the fourth column does not rely upon the entire key - but only a part of it. The course name is dependent on the Course's ID, but has nothing to do with which semester it's taken in. Thus, as you can see, we have duplicate information - several rows telling us that IT101 is programming, and IT102 is Databases. So we fix that by moving the course name into another table, where CourseID is the ENTIRE key.

Primary Key |

CourseID    |  Course Name |
---------------------------|
IT101       | Programming  |
IT102       | Databases    |
IT103       | Web Design   |

No redundancy!

3NF

Okay, so let's say we also add the name of the teacher of the course, and some details about them, into the RDBMS:

|-----Primary Key----|                           uh oh |
                                                       V
Course  |  Semester  |  #Places   |  TeacherID  | TeacherName  |
---------------------------------------------------------------|
IT101   |   2009-1   |  100       |  332        |  Mr Jones    |
IT101   |   2009-2   |  100       |  332        |  Mr Jones    |
IT102   |   2009-1   |  200       |  495        |  Mr Bentley  |
IT102   |   2010-1   |  150       |  332        |  Mr Jones    |
IT103   |   2009-2   |  120       |  242        |  Mrs Smith   |

Now hopefully it should be obvious that TeacherName is dependent on TeacherID - so this is not in 3NF. To fix this, we do much the same as we did in 2NF - take the TeacherName field out of this table, and put it in its own, which has TeacherID as the key.

 Primary Key |

 TeacherID   | TeacherName  |
 ---------------------------|
 332         |  Mr Jones    |
 495         |  Mr Bentley  |
 242         |  Mrs Smith   |

No redundancy!!

One important thing to remember is that if something is not in 1NF, it is not in 2NF or 3NF either. So each additional Normal Form requires everything that the lower normal forms had, plus some extra conditions, which must all be fulfilled.

What is the difference between static_cast<> and C style casting?

struct A {};
struct B : A {};
struct C {}; 

int main()
{
    A* a = new A;    

    int i = 10;

    a = (A*) (&i); // NO ERROR! FAIL!

    //a = static_cast<A*>(&i); ERROR! SMART!

    A* b = new B;

    B* b2 = static_cast<B*>(b); // NO ERROR! SMART!

    C* c = (C*)(b); // NO ERROR! FAIL!

    //C* c = static_cast<C*>(b); ERROR! SMART!
}

How to get tf.exe (TFS command line client)?

You can also try TFS CLI for Node.js which is a cross-platform CLI for Microsoft Team Foundation Server and Visual Studio Team Services.

Get Root Directory Path of a PHP project

I want to point to the way Wordpress handles this:

define( 'ABSPATH', dirname( __FILE__ ) . '/' );

As Wordpress is very heavy used all over the web and also works fine locally I have much trust in this method. You can find this definition on the bottom of your wordpress wp-config.php file

Is there an easy way to convert Android Application to IPad, IPhone

In the box is working on being able to convert android projects to iOS

https://code.google.com/p/in-the-box/

MySQL TEXT vs BLOB vs CLOB

TEXT is a data-type for text based input. On the other hand, you have BLOB and CLOB which are more suitable for data storage (images, etc) due to their larger capacity limits (4GB for example).

As for the difference between BLOB and CLOB, I believe CLOB has character encoding associated with it, which implies it can be suited well for very large amounts of text.

BLOB and CLOB data can take a long time to retrieve, relative to how quick data from a TEXT field can be retrieved. So, use only what you need.

cut or awk command to print first field of first row

try this:

head -1 /etc/*release | awk '{print $1}'

How to apply a low-pass or high-pass filter to an array in Matlab?

Look at the filter function.

If you just need a 1-pole low-pass filter, it's

xfilt = filter(a, [1 a-1], x);

where a = T/τ, T = the time between samples, and τ (tau) is the filter time constant.

Here's the corresponding high-pass filter:

xfilt = filter([1-a a-1],[1 a-1], x);

If you need to design a filter, and have a license for the Signal Processing Toolbox, there's a bunch of functions, look at fvtool and fdatool.

How to add a .dll reference to a project in Visual Studio

You probably are looking for AddReference dialog accessible from Project Context Menu (right click..)

From there you can reference dll's, after which you can reference namespaces that you need in your code.

Best way to define error codes/strings in Java?

I (and the rest of our team in my company) prefer to raise exceptions instead of returning error codes. Error codes have to be checked everywhere, passed around, and tend to make the code unreadable when the amount of code becomes bigger.

The error class would then define the message.

PS: and actually also care for internationalization !
PPS: you could also redefine the raise-method and add logging, filtering etc. if required (at leastin environments, where the Exception classes and friends are extendable/changeable)

React fetch data in server before render

A very simple example of this

import React, { Component } from 'react';
import { View, Text } from 'react-native';

export default class App extends React.Component  {

    constructor(props) {
      super(props);

      this.state = {
        data : null
      };
    }

    componentWillMount() {
        this.renderMyData();
    }

    renderMyData(){
        fetch('https://your url')
            .then((response) => response.json())
            .then((responseJson) => {
              this.setState({ data : responseJson })
            })
            .catch((error) => {
              console.error(error);
            });
    }

    render(){
        return(
            <View>
                {this.state.data ? <MyComponent data={this.state.data} /> : <MyLoadingComponnents /> }
            </View>
        );
    }
}

VBA Excel - Insert row below with same format including borders and frames

Private Sub cmdInsertRow_Click()

    Dim lRow As Long
    Dim lRsp As Long
    On Error Resume Next

    lRow = Selection.Row()
    lRsp = MsgBox("Insert New row above " & lRow & "?", _
            vbQuestion + vbYesNo)
    If lRsp <> vbYes Then Exit Sub

    Rows(lRow).Select
    Selection.Copy
    Rows(lRow + 1).Select
    Selection.Insert Shift:=xlDown
    Application.CutCopyMode = False

   'Paste formulas and conditional formatting in new row created
    Rows(lRow).PasteSpecial Paste:=xlPasteFormulas, Operation:=xlNone

End Sub

This is what I use. Tested and working,

Thanks,

The imported project "C:\Microsoft.CSharp.targets" was not found

This link on MSDN also helps a lot to understand the reason why it doesn't work. $(MSBuildToolsPath) is the path to Microsoft.Build.Engine v3.5 (inserted automatically in a project file when you create in VS2008). If you try to build your project for .Net 2.0, be sure that you changed this path to $(MSBuildBinPath) which is the path to Microsoft.Build.Engine v2.0.

Multiple HttpPost method in Web API controller

Put Route Prefix [RoutePrefix("api/Profiles")] at the controller level and put a route at action method [Route("LikeProfile")]. Don't need to change anything in global.asax file

namespace KhandalVipra.Controllers
{
    [RoutePrefix("api/Profiles")]
    public class ProfilesController : ApiController
    {
        // POST: api/Profiles/LikeProfile
        [Authorize]
        [HttpPost]
        [Route("LikeProfile")]
        [ResponseType(typeof(List<Like>))]
        public async Task<IHttpActionResult> LikeProfile()
        {
        }
    }
}