Programs & Examples On #Query builder

A query-builder is a set of classes and methods that is able to programmatically build queries.

Select entries between dates in doctrine 2

Look how I format my date $jour in the parameters. It depends if you use a expr()->like or a expr()->lte

$qb
        ->select('e')
        ->from('LdbPlanningBundle:EventEntity', 'e')
        ->where(
            $qb->expr()->andX(
                $qb->expr()->orX(
                    $qb->expr()->like('e.start', ':jour1'),
                    $qb->expr()->like('e.end', ':jour1'),
                    $qb->expr()->andX(
                        $qb->expr()->lte('e.start', ':jour2'),
                        $qb->expr()->gte('e.end', ':jour2')
                    )
                ),
                $qb->expr()->eq('e.user', ':user')
            )
        )
        ->andWhere('e.user = :user ')
        ->setParameter('user', $user)
        ->setParameter('jour1', '%'.$jour->format('Y-m-d').'%')
        ->setParameter('jour2', $jour->format('Y-m-d'))
        ->getQuery()
        ->getArrayResult()
    ;

How to select from subquery using Laravel Query Builder?

The solution of @JarekTkaczyk it is exactly what I was looking for. The only thing I miss is how to do it when you are using DB::table() queries. In this case, this is how I do it:

$other = DB::table( DB::raw("({$sub->toSql()}) as sub") )->select(
    'something', 
    DB::raw('sum( qty ) as qty'), 
    'foo', 
    'bar'
);
$other->mergeBindings( $sub );
$other->groupBy('something');
$other->groupBy('foo');
$other->groupBy('bar');
print $other->toSql();
$other->get();

Special atention how to make the mergeBindings without using the getQuery() method

Laravel whereIn OR whereIn

You have a orWhereIn function in Laravel. It takes the same parameters as the whereIn function.

It's not in the documentation but you can find it in the laravel API. http://laravel.com/api/4.1/

That should give you this:

$query-> orWhereIn('products.value', $f);

How to select distinct query using symfony2 doctrine query builder?

This works:

$category = $catrep->createQueryBuilder('cc')
        ->select('cc.categoryid')
        ->where('cc.contenttype = :type')
        ->setParameter('type', 'blogarticle')
        ->distinct()
        ->getQuery();

$categories = $category->getResult();

Edit for Symfony 3 & 4.

You should use ->groupBy('cc.categoryid') instead of ->distinct()

Laravel Query Builder where max id

For Laravel ^5

Orders::max('id');

I used it is short and best;

How to use WHERE IN with Doctrine 2

I found that, despite what the docs indicate, the only way to get this to work is like this:

$ids = array(...); // Array of your values
$qb->add('where', $qb->expr()->in('r.winner', $ids));

http://groups.google.com/group/doctrine-dev/browse_thread/thread/fbf70837293676fb

DB query builder toArray() laravel 4

toArray is a model method of Eloquent, so you need to a Eloquent model, try this:

 User::where('name', '=', 'Jhon')->get()->toArray();

http://laravel.com/docs/eloquent#collections

Laravel 5.2 - pluck() method returns array

laravel pluck returns an array

if your query is:

 $name = DB::table('users')->where('name', 'John')->pluck('name');

then the array is like this (key is the index of the item. auto incremented value):

[
    1 => "name1",
    2 => "name2",
    .
    .
    .
    100 => "name100"
]

but if you do like this:

$name = DB::table('users')->where('name', 'John')->pluck('name','id');

then the key is actual index in the database.

key||value
[
    1 => "name1",
    2 => "name2",
    .
    .
    .
    100 => "name100"
]

you can set any value as key.

Jquery Validate custom error message location

What you should use is the errorLabelContainer

_x000D_
_x000D_
jQuery(function($) {_x000D_
  var validator = $('#form').validate({_x000D_
    rules: {_x000D_
      first: {_x000D_
        required: true_x000D_
      },_x000D_
      second: {_x000D_
        required: true_x000D_
      }_x000D_
    },_x000D_
    messages: {},_x000D_
    errorElement : 'div',_x000D_
    errorLabelContainer: '.errorTxt'_x000D_
  });_x000D_
});
_x000D_
.errorTxt{_x000D_
  border: 1px solid red;_x000D_
  min-height: 20px;_x000D_
}
_x000D_
<script type="text/javascript" src="http://code.jquery.com/jquery-1.11.1.js"></script>_x000D_
<script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.12.0/jquery.validate.js"></script>_x000D_
<script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.12.0/additional-methods.js"></script>_x000D_
_x000D_
<form id="form" method="post" action="">_x000D_
  <input type="text" name="first" />_x000D_
  <input type="text" name="second" />_x000D_
  <div class="errorTxt"></div>_x000D_
  <input type="submit" class="button" value="Submit" />_x000D_
</form>
_x000D_
_x000D_
_x000D_


If you want to retain your structure then

_x000D_
_x000D_
jQuery(function($) {_x000D_
  var validator = $('#form').validate({_x000D_
    rules: {_x000D_
      first: {_x000D_
        required: true_x000D_
      },_x000D_
      second: {_x000D_
        required: true_x000D_
      }_x000D_
    },_x000D_
    messages: {},_x000D_
    errorPlacement: function(error, element) {_x000D_
      var placement = $(element).data('error');_x000D_
      if (placement) {_x000D_
        $(placement).append(error)_x000D_
      } else {_x000D_
        error.insertAfter(element);_x000D_
      }_x000D_
    }_x000D_
  });_x000D_
});
_x000D_
#errNm1 {_x000D_
  border: 1px solid red;_x000D_
}_x000D_
#errNm2 {_x000D_
  border: 1px solid green;_x000D_
}
_x000D_
<script type="text/javascript" src="http://code.jquery.com/jquery-1.11.1.js"></script>_x000D_
<script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.12.0/jquery.validate.js"></script>_x000D_
<script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.12.0/additional-methods.js"></script>_x000D_
_x000D_
<form id="form" method="post" action="">_x000D_
  <input type="text" name="first" data-error="#errNm1" />_x000D_
  <input type="text" name="second" data-error="#errNm2" />_x000D_
  <div class="errorTxt">_x000D_
    <span id="errNm2"></span>_x000D_
    <span id="errNm1"></span>_x000D_
  </div>_x000D_
  <input type="submit" class="button" value="Submit" />_x000D_
</form>
_x000D_
_x000D_
_x000D_

Get SSID when WIFI is connected

This is a follow up to the answer given by @EricWoodruff.

You could use netInfo's getExtraInfo() to get wifi SSID.

if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals (action)) {
    NetworkInfo netInfo = intent.getParcelableExtra (WifiManager.EXTRA_NETWORK_INFO);
    if (ConnectivityManager.TYPE_WIFI == netInfo.getType ()) {
        String ssid = info.getExtraInfo()
        Log.d(TAG, "WiFi SSID: " + ssid)
    }
}

If you are not using BroadcastReceiver check this answer to get SSID using Context

This is tested on Android Oreo 8.1.0

What is the difference between compare() and compareTo()?

The methods do not have to give the same answers. That depends on which objects/classes you call them.

If you are implementing your own classes which you know you want to compare at some stage, you may have them implement the Comparable interface and implement the compareTo() method accordingly.

If you are using some classes from an API which do not implement the Comparable interface, but you still want to compare them. I.e. for sorting. You may create your own class which implements the Comparator interface and in its compare() method you implement the logic.

How to use View.OnTouchListener instead of onClick

for use sample touch listener just you need this code

@Override
public boolean onTouch(View view, MotionEvent motionEvent) {

    ClipData data = ClipData.newPlainText("", "");
    View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view);
    view.startDrag(data, shadowBuilder, null, 0);

    return true;
}

How to read a text file into a list or an array with Python

So you want to create a list of lists... We need to start with an empty list

list_of_lists = []

next, we read the file content, line by line

with open('data') as f:
    for line in f:
        inner_list = [elt.strip() for elt in line.split(',')]
        # in alternative, if you need to use the file content as numbers
        # inner_list = [int(elt.strip()) for elt in line.split(',')]
        list_of_lists.append(inner_list)

A common use case is that of columnar data, but our units of storage are the rows of the file, that we have read one by one, so you may want to transpose your list of lists. This can be done with the following idiom

by_cols = zip(*list_of_lists)

Another common use is to give a name to each column

col_names = ('apples sold', 'pears sold', 'apples revenue', 'pears revenue')
by_names = {}
for i, col_name in enumerate(col_names):
    by_names[col_name] = by_cols[i]

so that you can operate on homogeneous data items

 mean_apple_prices = [money/fruits for money, fruits in
                     zip(by_names['apples revenue'], by_names['apples_sold'])]

Most of what I've written can be speeded up using the csv module, from the standard library. Another third party module is pandas, that lets you automate most aspects of a typical data analysis (but has a number of dependencies).


Update While in Python 2 zip(*list_of_lists) returns a different (transposed) list of lists, in Python 3 the situation has changed and zip(*list_of_lists) returns a zip object that is not subscriptable.

If you need indexed access you can use

by_cols = list(zip(*list_of_lists))

that gives you a list of lists in both versions of Python.

On the other hand, if you don't need indexed access and what you want is just to build a dictionary indexed by column names, a zip object is just fine...

file = open('some_data.csv')
names = get_names(next(file))
columns = zip(*((x.strip() for x in line.split(',')) for line in file)))
d = {}
for name, column in zip(names, columns): d[name] = column

Send array with Ajax to PHP script

If you have been trying to send a one dimentional array and jquery was converting it to comma separated values >:( then follow the code below and an actual array will be submitted to php and not all the comma separated bull**it.

Say you have to attach a single dimentional array named myvals.

jQuery('#someform').on('submit', function (e) {
    e.preventDefault();
    var data = $(this).serializeArray();

    var myvals = [21, 52, 13, 24, 75]; // This array could come from anywhere you choose 
    for (i = 0; i < myvals.length; i++) {
        data.push({
            name: "myvals[]", // These blank empty brackets are imp!
            value: myvals[i]
        });
    }

jQuery.ajax({
    type: "post",
    url: jQuery(this).attr('action'),
    dataType: "json",
    data: data, // You have to just pass our data variable plain and simple no Rube Goldberg sh*t.
    success: function (r) {
...

Now inside php when you do this

print_r($_POST);

You will get ..

Array
(
    [someinputinsidetheform] => 023
    [anotherforminput] => 111
    [myvals] => Array
        (
            [0] => 21
            [1] => 52
            [2] => 13
            [3] => 24
            [4] => 75
        )
)

Pardon my language, but there are hell lot of Rube-Goldberg solutions scattered all over the web and specially on SO, but none of them are elegant or solve the problem of actually posting a one dimensional array to php via ajax post. Don't forget to spread this solution.

Docker is installed but Docker Compose is not ? why?

I'm installing on a Raspberry Pi 3, on Raspbian OS. The curl method didn't resolve to a valid response. It also said {error: Not Found}, I took a look at the URL https://github.com/docker/compose/releases/download/1.11.2/docker-compose-Linux-armv7l and it was not valid. I guess there was no build there.

This guide https://github.com/hypriot/arm-compose worked for me.

sudo apt-get update
sudo apt-get install -y apt-transport-https
echo "deb https://packagecloud.io/Hypriot/Schatzkiste/debian/ jessie main" | sudo tee /etc/apt/sources.list.d/hypriot.list
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 37BBEE3F7AD95B3F
sudo apt-get update
sudo apt-get install docker-compose

Run bash script as daemon

To run it as a full daemon from a shell, you'll need to use setsid and redirect its output. You can redirect the output to a logfile, or to /dev/null to discard it. Assuming your script is called myscript.sh, use the following command:

setsid myscript.sh >/dev/null 2>&1 < /dev/null &

This will completely detach the process from your current shell (stdin, stdout and stderr). If you want to keep the output in a logfile, replace the first /dev/null with your /path/to/logfile.

You have to redirect the output, otherwise it will not run as a true daemon (it will depend on your shell to read and write output).

Is there a way to split a widescreen monitor in to two or more virtual monitors?

The only software that I found that already exists is Matrox PowerDesk. Among other things it lets you split a monitor into 2 virtual desktops. You have to have a compatible matrox video card though. It also does a bunch of other multi-monitor functions.

KnockoutJs v2.3.0 : Error You cannot apply bindings multiple times to the same element

I finally solved mine by returning { controlsDescendantBindings: true } in the init function of the binding handler. See this

Reading a UTF8 CSV file with Python

The link to the help page is the same for python 2.6 and as far as I know there was no change in the csv module since 2.5 (besides bug fixes). Here is the code that just works without any encoding/decoding (file da.csv contains the same data as the variable data). I assume that your file should be read correctly without any conversions.

test.py:

## -*- coding: utf-8 -*-
#
# NOTE: this first line is important for the version b) read from a string(unicode) variable
#

import csv

data = \
"""0665000FS10120684,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Bleu
0665000FS10120689,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Gris
0665000FS10120687,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Vert"""

# a) read from a file
print 'reading from a file:'
for (f1, f2, f3) in csv.reader(open('da.csv'), dialect=csv.excel):
    print (f1, f2, f3)

# b) read from a string(unicode) variable
print 'reading from a list of strings:'
reader = csv.reader(data.split('\n'), dialect=csv.excel)
for (f1, f2, f3) in reader:
    print (f1, f2, f3)

da.csv:

0665000FS10120684,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Bleu
0665000FS10120689,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Gris
0665000FS10120687,SD1200IS,Appareil photo numérique PowerShot de 10 Mpx de Canon avec trépied (SD1200IS) - Vert

using CASE in the WHERE clause

This is working Oracle example but it should work in MySQL too.

You are missing smth - see IN after END Replace 'IN' with '=' sign for a single value.

SELECT empno, ename, job
  FROM scott.emp
 WHERE (CASE WHEN job = 'MANAGER' THEN '1'  
         WHEN job = 'CLERK'   THEN '2' 
         ELSE '0'  END) IN (1, 2)

CSS3 equivalent to jQuery slideUp and slideDown?

Getting height transitions to work can be a bit tricky mainly because you have to know the height to animate for. This is further complicated by padding in the element to be animated.

Here is what I came up with:

use a style like this:

    .slideup, .slidedown {
        max-height: 0;            
        overflow-y: hidden;
        -webkit-transition: max-height 0.8s ease-in-out;
        -moz-transition: max-height 0.8s ease-in-out;
        -o-transition: max-height 0.8s ease-in-out;
        transition: max-height 0.8s ease-in-out;
    }
    .slidedown {            
        max-height: 60px ;  // fixed width                  
    }

Wrap your content into another container so that the container you're sliding has no padding/margins/borders:

  <div id="Slider" class="slideup">
    <!-- content has to be wrapped so that the padding and
            margins don't effect the transition's height -->
    <div id="Actual">
            Hello World Text
        </div>
  </div>

Then use some script (or declarative markup in binding frameworks) to trigger the CSS classes.

  $("#Trigger").click(function () {
    $("#Slider").toggleClass("slidedown slideup");
  });

Example here: http://plnkr.co/edit/uhChl94nLhrWCYVhRBUF?p=preview

This works fine for fixed size content. For a more generic soltution you can use code to figure out the size of the element when the transition is activated. The following is a jQuery plug-in that does just that:

$.fn.slideUpTransition = function() {
    return this.each(function() {
        var $el = $(this);
        $el.css("max-height", "0");
        $el.addClass("height-transition-hidden");
    });
};

$.fn.slideDownTransition = function() {
    return this.each(function() {
        var $el = $(this);
        $el.removeClass("height-transition-hidden");

        // temporarily make visible to get the size
        $el.css("max-height", "none");
        var height = $el.outerHeight();

        // reset to 0 then animate with small delay
        $el.css("max-height", "0");

        setTimeout(function() {
            $el.css({
                "max-height": height
            });
        }, 1);
    });
};

which can be triggered like this:

$("#Trigger").click(function () {

    if ($("#SlideWrapper").hasClass("height-transition-hidden"))
        $("#SlideWrapper").slideDownTransition();
    else
        $("#SlideWrapper").slideUpTransition();
});

against markup like this:

<style>
#Actual {
    background: silver;
    color: White;
    padding: 20px;
}

.height-transition {
    -webkit-transition: max-height 0.5s ease-in-out;
    -moz-transition: max-height 0.5s ease-in-out;
    -o-transition: max-height 0.5s ease-in-out;
    transition: max-height 0.5s ease-in-out;
    overflow-y: hidden;            
}
.height-transition-hidden {            
    max-height: 0;            
}
</style>
<div id="SlideWrapper" class="height-transition height-transition-hidden">
    <!-- content has to be wrapped so that the padding and
        margins don't effect the transition's height -->
    <div id="Actual">
     Your actual content to slide down goes here.
    </div>
</div>

Example: http://plnkr.co/edit/Wpcgjs3FS4ryrhQUAOcU?p=preview

I wrote this up recently in a blog post if you're interested in more detail:

http://weblog.west-wind.com/posts/2014/Feb/22/Using-CSS-Transitions-to-SlideUp-and-SlideDown

How to obtain the absolute path of a file via Shell (BASH/ZSH/SH)?

There is generally no such thing as the absolute path to a file (this statement means that there may be more than one in general, hence the use of the definite article the is not appropriate). An absolute path is any path that start from the root "/" and designates a file without ambiguity independently of the working directory.(see for example wikipedia).

A relative path is a path that is to be interpreted starting from another directory. It may be the working directory if it is a relative path being manipulated by an application (though not necessarily). When it is in a symbolic link in a directory, it is generally intended to be relative to that directory (though the user may have other uses in mind).

Hence an absolute path is just a path relative to the root directory.

A path (absolute or relative) may or may not contain symbolic links. If it does not, it is also somewhat impervious to changes in the linking structure, but this is not necessarily required or even desirable. Some people call canonical path ( or canonical file name or resolved path) an absolute path in which all symbolic links have been resolved, i.e. have been replaced by a path to whetever they link to. The commands realpath and readlink both look for a canonical path, but only realpath has an option for getting an absolute path without bothering to resolve symbolic links (along with several other options to get various kind of paths, absolute or relative to some directory).

This calls for several remarks:

  1. symbolic links can only be resolved if whatever they are supposed to link to is already created, which is obviously not always the case. The commands realpath and readlink have options to account for that.
  2. a directory on a path can later become a symbolic link, which means that the path is no longer canonical. Hence the concept is time (or environment) dependent.
  3. even in the ideal case, when all symbolic links can be resolved, there may still be more than one canonical path to a file, for two reasons:
    • the partition containing the file may have been mounted simultaneously (ro) on several mount points.
    • there may be hard links to the file, meaning essentially the the file exists in several different directories.

Hence, even with the much more restrictive definition of canonical path, there may be several canonical paths to a file. This also means that the qualifier canonical is somewhat inadequate since it usually implies a notion of uniqueness.

This expands a brief discussion of the topic in an answer to another similar question at Bash: retrieve absolute path given relative

My conclusion is that realpath is better designed and much more flexible than readlink. The only use of readlink that is not covered by realpath is the call without option returning the value of a symbolic link.

How to display list items on console window in C#

Assume that we need to view some data in command prompt which are coming from a database table. First we create a list. Team_Details is my property class.

    List<Team_Details> teamDetails = new List<Team_Details>();

Then you can connect to the database and do the data retrieving part and save it to the list as follows.

            string connetionString = "Data Source=.;Initial Catalog=your DB name;Integrated Security=True;MultipleActiveResultSets=True";
            using (SqlConnection conn = new SqlConnection(connetionString)){
            string getTeamDetailsQuery = "select * from Team";
            conn.Open();
            using (SqlCommand cmd = new SqlCommand(getTeamDetailsQuery, conn))
                    {
                        SqlDataReader rdr = cmd.ExecuteReader();
                    {
                        teamDetails.Add(new Team_Details
                        {
                            Team_Name = rdr.GetString(rdr.GetOrdinal("Team_Name")),
                            Team_Lead = rdr.GetString(rdr.GetOrdinal("Team_Lead")),
                        });
                    }

Then you can print this list in command prompt as follows.

foreach (Team_Details i in teamDetails)
                        {
                            Console.WriteLine(i.Team_Name);
                            Console.WriteLine(i.Team_Lead);
                        }

How to solve error message: "Failed to map the path '/'."

I had the same issue (MVC 4) under IIS 7. It turned out that the App Pool identity didn't have the correct authorization to the site's path.

Can linux cat command be used for writing text to file?

cat > filename.txt

enter the text until EOF for save the text use : ctrl+d

if you want to read that .txt file use

cat filename.txt

and one thing .txt is not mandatory, its for your reference.

Precision String Format Specifier In Swift

I don't know about two decimal places, but here's how you can print floats with zero decimal places, so I'd imagine that can be 2 place, 3, places ... (Note: you must convert CGFloat to Double to pass to String(format:) or it will see a value of zero)

func logRect(r: CGRect, _ title: String = "") {
    println(String(format: "[ (%.0f, %.0f), (%.0f, %.0f) ] %@",
        Double(r.origin.x), Double(r.origin.y), Double(r.size.width), Double(r.size.height), title))
}

iOS 7 - Status bar overlaps the view

To hide status bar in ios7 follow these simple steps :

In Xcode goto "Resources" folder and open "(app name)-Info.plist file".

  • check for "View controller based status bar appearance" key and set its value "NO"
  • check for "Status bar is initially hidden" key and set its value "YES"

If the keys are not there then you can add it by selecting "information property list" at top and click + icon

Mvn install or Mvn package

mvn install is the option that is most often used.
mvn package is seldom used, only if you're debugging some issue with the maven build process.

See: http://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html

Note that mvn package will only create a jar file.
mvn install will do that and install the jar (and class etc.) files in the proper places if other code depends on those jars.

I usually do a mvn clean install; this deletes the target directory and recreates all jars in that location.
The clean helps with unneeded or removed stuff that can sometimes get in the way.
Rather then debug (some of the time) just start fresh all of the time.

Multiple FROMs - what it means

As of May 2017, multiple FROMs can be used in a single Dockerfile.
See "Builder pattern vs. Multi-stage builds in Docker" (by Alex Ellis) and PR 31257 by Tõnis Tiigi.

The general syntax involves adding FROM additional times within your Dockerfile - whichever is the last FROM statement is the final base image. To copy artifacts and outputs from intermediate images use COPY --from=<base_image_number>.

FROM golang:1.7.3 as builder
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v golang.org/x/net/html  
COPY app.go    .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/github.com/alexellis/href-counter/app    .
CMD ["./app"]  

The result would be two images, one for building, one with just the resulting app (much, much smaller)

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

multi               latest              bcbbf69a9b59        6 minutes ago       10.3MB  
golang              1.7.3               ef15416724f6        4 months ago        672MB  

what is a base image?

A set of files, plus EXPOSE'd ports, ENTRYPOINT and CMD.
You can add files and build a new image based on that base image, with a new Dockerfile starting with a FROM directive: the image mentioned after FROM is "the base image" for your new image.

does it mean that if I declare neo4j/neo4j in a FROM directive, that when my image is run the neo database will automatically run and be available within the container on port 7474?

Only if you don't overwrite CMD and ENTRYPOINT.
But the image in itself is enough: you would use a FROM neo4j/neo4j if you had to add files related to neo4j for your particular usage of neo4j.

Python: Removing spaces from list objects

replace() does not operate in-place, you need to assign its result to something. Also, for a more concise syntax, you could supplant your for loop with a one-liner: hello_no_spaces = map(lambda x: x.replace(' ', ''), hello)

Can I pass variable to select statement as column name in SQL Server

You can't use variable names to bind columns or other system objects, you need dynamic sql

DECLARE @value varchar(10)  
SET @value = 'intStep'  
DECLARE @sqlText nvarchar(1000); 

SET @sqlText = N'SELECT ' + @value + ' FROM dbo.tblBatchDetail'
Exec (@sqlText)

How do I extend a class with c# extension methods?

They provide the capability to extend existing types by adding new methods with no modifications necessary to the type. Calling methods from objects of the extended type within an application using instance method syntax is known as ‘‘extending’’ methods. Extension methods are not instance members on the type. The key point to remember is that extension methods, defined as static methods, are in scope only when the namespace is explicitly imported into your application source code via the using directive. Even though extension methods are defined as static methods, they are still called using instance syntax.

Check the full example here http://www.dotnetreaders.com/articles/Extension_methods_in_C-sharp.net,Methods_in_C_-sharp/201

Example:

class Extension
    {
        static void Main(string[] args)
        {
            string s = "sudhakar";
            Console.WriteLine(s.GetWordCount());
            Console.ReadLine();
        }

    }
    public static class MyMathExtension
    {

        public static int GetWordCount(this System.String mystring)
        {
            return mystring.Length;
        }
    }

Change multiple files

Those commands won't work in the default sed that comes with Mac OS X.

From man 1 sed:

-i extension
             Edit files in-place, saving backups with the specified
             extension.  If a zero-length extension is given, no backup 
             will be saved.  It is not recommended to give a zero-length
             extension when in-place editing files, as you risk corruption
             or partial content in situations where disk space is exhausted, etc.

Tried

sed -i '.bak' 's/old/new/g' logfile*

and

for i in logfile*; do sed -i '.bak' 's/old/new/g' $i; done

Both work fine.

how do I use an enum value on a switch statement in C++

You're on the right track. You may read the user input into an integer and switch on that:

enum Choice
{
  EASY = 1, 
  MEDIUM = 2, 
  HARD = 3
};

int i = -1;

// ...<present the user with a menu>...

cin >> i;

switch(i)
{
  case EASY:
    cout << "Easy\n";
    break;
  case MEDIUM:
    cout << "Medium\n";
    break;
  case HARD:
    cout << "Hard\n";
    break;
  default:
    cout << "Invalid Selection\n";
    break;
}

Looping through all the properties of object php

Before you run the $object through a foreach loop you have to convert it to an array:

$array = (array) $object;  

 foreach($array as $key=>$val){
      echo "$key: $val";
      echo "<br>";
 }

What is the difference between an abstract function and a virtual function?

If a class derives from this abstract class, it is then forced to override the abstract member. This is different from the virtual modifier, which specifies that the member may optionally be overridden.

PHP list of specific files in a directory

You can extend the RecursiveFilterIterator class like this:

class ExtensionFilter extends RecursiveFilterIterator
{
  /**
  * Hold the extensions pass to the class constructor 
  */
  protected $extensions;

  /**
   * ExtensionFilter constructor.
   *  
   * @param RecursiveIterator $iterator
   * @param string|array $extensions Extension to filter as an array ['php'] or
   * as string with commas in between 'php, exe, ini'
   */
  public function __construct(RecursiveIterator $iterator, $extensions)
  {
     parent::__construct($iterator);
     $this->extensions = is_array($extensions) ? $extensions :  array_map('trim', explode(',', $extensions));
  }

  public function accept()
  {
      if ($this->hasChildren()) {
         return true;
      }

      return $this->current()->isFile() &&
         in_array(strtolower($this->current()->getExtension()), $this->extensions);
  }

  public function getChildren()
  {
     return new self($this->getInnerIterator()->getChildren(), $this->extensions);
  }

Now you can instantiate RecursiveDirectoryIterator with path as an argument like this:

 $iterator = new RecursiveDirectoryIterator('\path\to\dir');
 $iterator = new ExtensionFilter($iterator, 'xml, php, ini');

 foreach($iterator as $file)
 {
   echo $file . '<br />';
 }

This will list files under the current folder only.

To get the files in subdirectories also, pass the $iterator ( ExtensionFIlter Iterator) to RecursiveIteratorIterator as argument:

$iterator = new RecursiveIteratorIterator($iterator, RecursiveIteratorIterator::SELF_FIRST);

Now run the foreach loop on this iterator. You will get the files with specified extension

Note:-- Also make sure to run the ExtensionFilter before RecursiveIteratorIterator, otherwise you will get all the files

Delete files older than 15 days using PowerShell

The given answers will only delete files (which admittedly is what is in the title of this post), but here's some code that will first delete all of the files older than 15 days, and then recursively delete any empty directories that may have been left behind. My code also uses the -Force option to delete hidden and read-only files as well. Also, I chose to not use aliases as the OP is new to PowerShell and may not understand what gci, ?, %, etc. are.

$limit = (Get-Date).AddDays(-15)
$path = "C:\Some\Path"

# Delete files older than the $limit.
Get-ChildItem -Path $path -Recurse -Force | Where-Object { !$_.PSIsContainer -and $_.CreationTime -lt $limit } | Remove-Item -Force

# Delete any empty directories left behind after deleting the old files.
Get-ChildItem -Path $path -Recurse -Force | Where-Object { $_.PSIsContainer -and (Get-ChildItem -Path $_.FullName -Recurse -Force | Where-Object { !$_.PSIsContainer }) -eq $null } | Remove-Item -Force -Recurse

And of course if you want to see what files/folders will be deleted before actually deleting them, you can just add the -WhatIf switch to the Remove-Item cmdlet call at the end of both lines.

The code shown here is PowerShell v2.0 compatible, but I also show this code and the faster PowerShell v3.0 code as handy reusable functions on my blog.

How to select distinct query using symfony2 doctrine query builder?

If you use the "select()" statement, you can do this:

$category = $catrep->createQueryBuilder('cc')
    ->select('DISTINCT cc.contenttype')
    ->Where('cc.contenttype = :type')
    ->setParameter('type', 'blogarticle')
    ->getQuery();

$categories = $category->getResult();

Oracle: what is the situation to use RAISE_APPLICATION_ERROR?

Just to elaborate a bit more on Henry's answer, you can also use specific error codes, from raise_application_error and handle them accordingly on the client side. For example:

Suppose you had a PL/SQL procedure like this to check for the existence of a location record:

   PROCEDURE chk_location_exists
   (
      p_location_id IN location.gie_location_id%TYPE
   )
   AS
      l_cnt INTEGER := 0;
   BEGIN
      SELECT COUNT(*)
        INTO l_cnt
        FROM location
       WHERE gie_location_id = p_location_id;

       IF l_cnt = 0
       THEN
          raise_application_error(
             gc_entity_not_found,
             'The associated location record could not be found.');
       END IF;
   END;

The raise_application_error allows you to raise a specific error code. In your package header, you can define: gc_entity_not_found INTEGER := -20001;

If you need other error codes for other types of errors, you can define other error codes using -20002, -20003, etc.

Then on the client side, you can do something like this (this example is for C#):

/// <summary>
/// <para>Represents Oracle error number when entity is not found in database.</para>
/// </summary>
private const int OraEntityNotFoundInDB = 20001;

And you can execute your code in a try/catch

try
{
   // call the chk_location_exists SP
}
catch (Exception e)
{
    if ((e is OracleException) && (((OracleException)e).Number == OraEntityNotFoundInDB))
    {
        // create an EntityNotFoundException with message indicating that entity was not found in
        // database; use the message of the OracleException, which will indicate the table corresponding
        // to the entity which wasn't found and also the exact line in the PL/SQL code where the application
        // error was raised
        return new EntityNotFoundException(
            "A required entity was not found in the database: " + e.Message);
    }
}

Rotate a div using javascript

I recently had to build something similar. You can check it out in the snippet below.

The version I had to build uses the same button to start and stop the spinner, but you can manipulate to code if you have a button to start the spin and a different button to stop the spin

Basically, my code looks like this...

Run Code Snippet

_x000D_
_x000D_
var rocket = document.querySelector('.rocket');_x000D_
var btn = document.querySelector('.toggle');_x000D_
var rotate = false;_x000D_
var runner;_x000D_
var degrees = 0;_x000D_
_x000D_
function start(){_x000D_
    runner = setInterval(function(){_x000D_
        degrees++;_x000D_
        rocket.style.webkitTransform = 'rotate(' + degrees + 'deg)';_x000D_
    },50)_x000D_
}_x000D_
_x000D_
function stop(){_x000D_
    clearInterval(runner);_x000D_
}_x000D_
_x000D_
btn.addEventListener('click', function(){_x000D_
    if (!rotate){_x000D_
        rotate = true;_x000D_
        start();_x000D_
    } else {_x000D_
        rotate = false;_x000D_
        stop();_x000D_
    }_x000D_
})
_x000D_
body {_x000D_
  background: #1e1e1e;_x000D_
}    _x000D_
_x000D_
.rocket {_x000D_
    width: 150px;_x000D_
    height: 150px;_x000D_
    margin: 1em;_x000D_
    border: 3px dashed teal;_x000D_
    border-radius: 50%;_x000D_
    background-color: rgba(128,128,128,0.5);_x000D_
    display: flex;_x000D_
    justify-content: center;_x000D_
    align-items: center;_x000D_
  }_x000D_
  _x000D_
  .rocket h1 {_x000D_
    margin: 0;_x000D_
    padding: 0;_x000D_
    font-size: .8em;_x000D_
    color: skyblue;_x000D_
    letter-spacing: 1em;_x000D_
    text-shadow: 0 0 10px black;_x000D_
  }_x000D_
  _x000D_
  .toggle {_x000D_
    margin: 10px;_x000D_
    background: #000;_x000D_
    color: white;_x000D_
    font-size: 1em;_x000D_
    padding: .3em;_x000D_
    border: 2px solid red;_x000D_
    outline: none;_x000D_
    letter-spacing: 3px;_x000D_
  }
_x000D_
<div class="rocket"><h1>SPIN ME</h1></div>_x000D_
<button class="toggle">I/0</button>
_x000D_
_x000D_
_x000D_

How do you Sort a DataTable given column and direction?

Create a DataView. You cannot sort a DataTable directly, but you can create a DataView from the DataTable and sort that.

Creating: http://msdn.microsoft.com/en-us/library/hy5b8exc.aspx

Sorting: http://msdn.microsoft.com/en-us/library/13wb36xf.aspx

The following code example creates a view that shows all the products where the number of units in stock is less than or equal to the reorder level, sorted first by supplier ID and then by product name.

DataView prodView = new DataView(prodDS.Tables["Products"], "UnitsInStock <= ReorderLevel", "SupplierID, ProductName", DataViewRowState.CurrentRows);

Correct owner/group/permissions for Apache 2 site files/folders under Mac OS X?

On my 10.6 system:

vhosts folder:
 owner:root
 group:wheel
 permissions:755

vhost.conf files:
 owner:root
 group:wheel
 permissions:644

jQuery - trapping tab select event

This post shows a complete working HTML file as an example of triggering code to run when a tab is clicked. The .on() method is now the way that jQuery suggests that you handle events.

jQuery development history

To make something happen when the user clicks a tab can be done by giving the list element an id.

<li id="list">

Then referring to the id.

$("#list").on("click", function() {
 alert("Tab Clicked!");
});

Make sure that you are using a current version of the jQuery api. Referencing the jQuery api from Google, you can get the link here:

https://developers.google.com/speed/libraries/devguide#jquery

Here is a complete working copy of a tabbed page that triggers an alert when the horizontal tab 1 is clicked.

<!-- This HTML doc is modified from an example by:  -->
<!-- http://keith-wood.name/uiTabs.html#tabs-nested -->

<head>
<meta charset="utf-8">
<title>TabDemo</title>

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.23/themes/south-street/jquery-ui.css">

<style>
pre {
clear: none;
}
div.showCode {
margin-left: 8em;
}
.tabs {
margin-top: 0.5em;
}
.ui-tabs { 
padding: 0.2em; 
background: url(http://code.jquery.com/ui/1.8.23/themes/south-street/images/ui-bg_highlight-hard_100_f5f3e5_1x100.png) repeat-x scroll 50% top #F5F3E5; 
border-width: 1px; 
} 
.ui-tabs .ui-tabs-nav { 
padding-left: 0.2em; 
background: url(http://code.jquery.com/ui/1.8.23/themes/south-street/images/ui-bg_gloss-wave_100_ece8da_500x100.png) repeat-x scroll 50% 50% #ECE8DA; 
border: 1px solid #D4CCB0;
-moz-border-radius: 6px; 
-webkit-border-radius: 6px; 
border-radius: 6px; 
} 
.ui-tabs-nav .ui-state-active {
border-color: #D4CCB0;
}
.ui-tabs .ui-tabs-panel { 
background: transparent; 
border-width: 0px; 
}
.ui-tabs-panel p {
margin-top: 0em;
}
#minImage {
margin-left: 6.5em;
}
#minImage img {
padding: 2px;
border: 2px solid #448844;
vertical-align: bottom;
}

#tabs-nested > .ui-tabs-panel {
padding: 0em;
}
#tabs-nested-left {
position: relative;
padding-left: 6.5em;
}
#tabs-nested-left .ui-tabs-nav {
position: absolute;
left: 0.25em;
top: 0.25em;
bottom: 0.25em;
width: 6em;
padding: 0.2em 0 0.2em 0.2em;
}
#tabs-nested-left .ui-tabs-nav li {
right: 1px;
width: 100%;
border-right: none;
border-bottom-width: 1px !important;
-moz-border-radius: 4px 0px 0px 4px;
-webkit-border-radius: 4px 0px 0px 4px;
border-radius: 4px 0px 0px 4px;
overflow: hidden;
}
#tabs-nested-left .ui-tabs-nav li.ui-tabs-selected,
#tabs-nested-left .ui-tabs-nav li.ui-state-active {
border-right: 1px solid transparent;
}
#tabs-nested-left .ui-tabs-nav li a {
float: right;
width: 100%;
text-align: right;
}
#tabs-nested-left > div {
height: 10em;
overflow: auto;
}
</pre>

</style>

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.23/jquery-ui.min.js"></script>

<script>
    $(function() {
    $('article.tabs').tabs();
    });
</script>

</head>
<body>
<header role="banner">
    <h1>jQuery UI Tabs Styling</h1>
</header>

<section>

<article id="tabs-nested" class="tabs">
<script>
    $(document).ready(function(){
    $("#ForClick").on("click", function() {
        alert("Tab Clicked!");
    });
    });
</script>
<ul>
    <li id="ForClick"><a href="#tabs-nested-1">First</a></li>
    <li><a href="#tabs-nested-2">Second</a></li>
    <li><a href="#tabs-nested-3">Third</a></li>
</ul>
<div id="tabs-nested-1">
    <article id="tabs-nested-left" class="tabs">
        <ul>
            <li><a href="#tabs-nested-left-1">First</a></li>
            <li><a href="#tabs-nested-left-2">Second</a></li>
            <li><a href="#tabs-nested-left-3">Third</a></li>
        </ul>
        <div id="tabs-nested-left-1">
            <p>Nested tabs, horizontal then vertical.</p>


<form action="/sign" method="post">
  <div><textarea name="content" rows="5" cols="100"></textarea></div>
  <div><input type="submit" value="Sign Guestbook"></div>
</form>
        </div>
        <div id="tabs-nested-left-2">
            <p>Nested Left Two</p>
        </div>
        <div id="tabs-nested-left-3">
            <p>Nested Left Three</p>
        </div>
    </article>
</div>
<div id="tabs-nested-2">
    <p>Tab Two Main</p>
</div>
<div id="tabs-nested-3">
    <p>Tab Three Main</p>
</div>
</article>

</section>

</body>
</html>

Laravel - Session store not set on request

Laravel [5.4]

My solution was to use global session helper: session()

Its functionality is a little bit harder than $request->session().

writing:

session(['key'=>'value']);

pushing:

session()->push('key', $notification);

retrieving:

session('key');

Display PDF file inside my android application

This is the perfect solution that worked for me without any 3rd party library.

Rendering a PDF Document in Android Activity/Fragment (Using PdfRenderer)

What is the difference between FragmentPagerAdapter and FragmentStatePagerAdapter?

FragmentStatePagerAdapter = To accommodate a large number of fragments in ViewPager. As this adapter destroys the fragment when it is not visible to the user and only savedInstanceState of the fragment is kept for further use. This way a low amount of memory is used and a better performance is delivered in case of dynamic fragments.

add/remove active class for ul list with jquery?

_x000D_
_x000D_
$(document).ready(function(){_x000D_
    $('.cliked').click(function() {_x000D_
        $(".cliked").removeClass("liactive");_x000D_
        $(this).addClass("liactive");_x000D_
    });_x000D_
});
_x000D_
.liactive {_x000D_
    background: orange;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<ul_x000D_
  className="sidebar-nav position-fixed "_x000D_
  style="height:450px;overflow:scroll"_x000D_
>_x000D_
    <li>_x000D_
        <a className="cliked liactive" href="#">_x000D_
            check Kyc Status_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            My Investments_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            My SIP_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            My Tax Savers Fund_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            Transaction History_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            Invest Now_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            My Profile_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            FAQ`s_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            Suggestion Portfolio_x000D_
        </a>_x000D_
    </li>_x000D_
    <li>_x000D_
        <a className="cliked" href="#">_x000D_
            Bluk Lumpsum / Bulk SIP_x000D_
        </a>_x000D_
    </li>_x000D_
</ul>;
_x000D_
_x000D_
_x000D_

How does one create an InputStream from a String?

Instead of CharSet.forName, using com.google.common.base.Charsets from Google's Guava (http://code.google.com/p/guava-libraries/wiki/StringsExplained#Charsets) is is slightly nicer:

InputStream is = new ByteArrayInputStream( myString.getBytes(Charsets.UTF_8) );

Which CharSet you use depends entirely on what you're going to do with the InputStream, of course.

Array from dictionary keys in swift

NSDictionary is Class(pass by reference) NSDictionary is class type Dictionary is Structure(pass by value) Dictionary is structure of key and value ====== Array from NSDictionary ======

NSDictionary has allKeys and allValues get properties with type [Any].NSDictionary has get [Any] properties for allkeys and allvalues

  let objesctNSDictionary = 
    NSDictionary.init(dictionary: ["BR": "Brazil", "GH": "Ghana", "JP": "Japan"])
            let objectArrayOfAllKeys:Array = objesctNSDictionary.allKeys
            let objectArrayOfAllValues:Array = objesctNSDictionary.allValues
            print(objectArrayOfAllKeys)
            print(objectArrayOfAllValues)

====== Array From Dictionary ======

Apple reference for Dictionary's keys and values properties. enter image description here

enter image description here

let objectDictionary:Dictionary = 
            ["BR": "Brazil", "GH": "Ghana", "JP": "Japan"]
    let objectArrayOfAllKeys:Array = Array(objectDictionary.keys)          
    let objectArrayOfAllValues:Array = Array(objectDictionary.values)
    print(objectArrayOfAllKeys)
    print(objectArrayOfAllValues)

Convert Numeric value to Varchar

i think it should be

select convert(varchar(10),StandardCost) +'S' from DimProduct where ProductKey = 212

or

select cast(StandardCost as varchar(10)) + 'S' from DimProduct where ProductKey = 212

jQuery: How can I create a simple overlay?

Here's a fully encapsulated version which adds an overlay (including a share button) to any IMG element where data-photo-overlay='true.

JSFiddle http://jsfiddle.net/wloescher/7y6UX/19/

HTML

<img id="my-photo-id" src="http://cdn.sstatic.net/stackexchange/img/logos/so/so-logo.png" alt="Photo" data-photo-overlay="true" />

CSS

#photoOverlay {
    background: #ccc;
    background: rgba(0, 0, 0, .5);
    display: none;
    height: 50px;
    left: 0;
    position: absolute;
    text-align: center;
    top: 0;
    width: 50px;
    z-index: 1000;
}

#photoOverlayShare {
    background: #fff;
    border: solid 3px #ccc;
    color: #ff6a00;
    cursor: pointer;
    display: inline-block;
    font-size: 14px;
    margin-left: auto;
    margin: 15px;
    padding: 5px;
    position: absolute;
    left: calc(100% - 100px);
    text-transform: uppercase;
    width: 50px;
}

JavaScript

(function () {
    // Add photo overlay hover behavior to selected images
    $("img[data-photo-overlay='true']").mouseenter(showPhotoOverlay);

    // Create photo overlay elements
    var _isPhotoOverlayDisplayed = false;
    var _photoId;
    var _photoOverlay = $("<div id='photoOverlay'></div>");
    var _photoOverlayShareButton = $("<div id='photoOverlayShare'>Share</div>");

    // Add photo overlay events
    _photoOverlay.mouseleave(hidePhotoOverlay);
    _photoOverlayShareButton.click(sharePhoto);

    // Add photo overlay elements to document
    _photoOverlay.append(_photoOverlayShareButton);
    _photoOverlay.appendTo(document.body);

    // Show photo overlay
    function showPhotoOverlay(e) {
        // Get sender 
        var sender = $(e.target || e.srcElement);

        // Check to see if overlay is already displayed
        if (!_isPhotoOverlayDisplayed) {
            // Set overlay properties based on sender
            _photoOverlay.width(sender.width());
            _photoOverlay.height(sender.height());

            // Position overlay on top of photo
            if (sender[0].x) {
                _photoOverlay.css("left", sender[0].x + "px");
                _photoOverlay.css("top", sender[0].y) + "px";
            }
            else {
                // Handle IE incompatibility
                _photoOverlay.css("left", sender.offset().left);
                _photoOverlay.css("top", sender.offset().top);
            }

            // Get photo Id
            _photoId = sender.attr("id");

            // Show overlay
            _photoOverlay.animate({ opacity: "toggle" });
            _isPhotoOverlayDisplayed = true;
        }
    }

    // Hide photo overlay
    function hidePhotoOverlay(e) {
        if (_isPhotoOverlayDisplayed) {
            _photoOverlay.animate({ opacity: "toggle" });
            _isPhotoOverlayDisplayed = false;
        }
    }

    // Share photo
    function sharePhoto() {
        alert("TODO: Share photo. [PhotoId = " + _photoId + "]");
        }
    }
)();

Bash script plugin for Eclipse?

I tried ShellEd, but it wouldn't recognize any of my shell scripts, even when I restarted eclipse. I added the ksh interpreter and made it the default, but it made no diffence.

Finally, I closed the tab that was open and displaying a ksh file, then re-opened it. That made it work correctly. After having used it for a while, I can also recommend it.

What does `void 0` mean?

void is a reserved JavaScript keyword. It evaluates the expression and always returns undefined.

How can I use delay() with show() and hide() in Jquery

from jquery api

Added to jQuery in version 1.4, the .delay() method allows us to delay the execution of functions that follow it in the queue. It can be used with the standard effects queue or with a custom queue. Only subsequent events in a queue are delayed; for example this will not delay the no-arguments forms of .show() or .hide() which do not use the effects queue.

http://api.jquery.com/delay/

Sort an array in Java

Arrays.sort(yourArray)

will do the job perfectly

JQuery Ajax Post results in 500 Internal Server Error

I was able to find the solution using the Chrome debugger (I don't have Firebug or other third-party tools installed)

  • Go to developer tab (CTRL+MAJ+I)
  • Network > click on the request which failed, in red > Preview

It showed me that I had a problem on the server, when I was returning a value which was self-referencing.

Showing/Hiding Table Rows with Javascript - can do with ID - how to do with Class?

JQuery 10.1.2 has a nice show and hide functions that encapsulate the behavior you are talking about. This would save you having to write a new function or keep track of css classes.

$("new").show();

$("new").hide();

w3cSchool link to JQuery show and hide

Reverse order of foreach list items

Walking Backwards

If you're looking for a purely PHP solution, you can also simply count backwards through the list, access it front-to-back:

$accounts = Array(
  '@jonathansampson',
  '@f12devtools',
  '@ieanswers'
);

$index = count($accounts);

while($index) {
  echo sprintf("<li>%s</li>", $accounts[--$index]);
}

The above sets $index to the total number of elements, and then begins accessing them back-to-front, reducing the index value for the next iteration.

Reversing the Array

You could also leverage the array_reverse function to invert the values of your array, allowing you to access them in reverse order:

$accounts = Array(
  '@jonathansampson',
  '@f12devtools',
  '@ieanswers'
);

foreach ( array_reverse($accounts) as $account ) {
  echo sprintf("<li>%s</li>", $account);
}

Deep copy an array in Angular 2 + TypeScript

The only solution I've found (almost instantly after posting the question), is to loop through the array and use Object.assign()

Like this:

public duplicateArray() {
  let arr = [];
  this.content.forEach((x) => {
    arr.push(Object.assign({}, x));
  })
  arr.map((x) => {x.status = DEFAULT});
  return this.content.concat(arr);
}

I know this is not optimal. And I wonder if there's any better solutions.

Get current time in milliseconds in Python?

time.time() may only give resolution to the second, the preferred approach for milliseconds is datetime.

from datetime import datetime
dt = datetime.now()
dt.microsecond

Open Popup window using javascript

First point is- showing multiple popups is not desirable in terms of usability.

But you can achieve it by using multiple popup names

var newwindow;
function createPop(url, name)
{    
   newwindow=window.open(url,name,'width=560,height=340,toolbar=0,menubar=0,location=0');  
   if (window.focus) {newwindow.focus()}
}

Better approach will be showing both in a single page in two different iFrames or Divs.

Update:

So I will suggest to create a new tab in the test.aspx page to show the report, instead of replacing the image content and placing the pdf.

What is the canonical way to trim a string in Ruby without creating a new string?

If you are using Ruby on Rails there is a squish

> @title = " abc "
 => " abc " 

> @title.squish
 => "abc"
> @title
 => " abc "

> @title.squish!
 => "abc"
> @title
 => "abc" 

If you are using just Ruby you want to use strip

Herein lies the gotcha.. in your case you want to use strip without the bang !

while strip! certainly does return nil if there was no action it still updates the variable so strip! cannot be used inline. If you want to use strip inline you can use the version without the bang !

strip! using multi line approach

> tokens["Title"] = " abc "
 => " abc "
> tokens["Title"].strip!
 => "abc"
> @title = tokens["Title"]
 => "abc"

strip single line approach... YOUR ANSWER

> tokens["Title"] = " abc "
 => " abc "
> @title = tokens["Title"].strip if tokens["Title"].present?
 => "abc"

How to remove specific element from an array using python

If you want to delete the index of array:

Use array_name.pop(index_no.)

ex:-

>>> arr = [1,2,3,4]
>>> arr.pop(2)
>>>arr
[1,2,4]

If you want to delete a particular string/element from the array then

>>> arr1 = ['python3.6' , 'python2' ,'python3']
>>> arr1.remove('python2')
>>> arr1
['python3.6','python3']

What are the most widely used C++ vector/matrix math/linear algebra libraries, and their cost and benefit tradeoffs?

I found this library quite simple and functional (http://kirillsprograms.com/top_Vectors.php). These are bare bone vectors implemented via C++ templates. No fancy stuff - just what you need to do with vectors (add, subtract multiply, dot, etc).

How to simulate a mouse click using JavaScript?

JavaScript Code

   //this function is used to fire click event
    function eventFire(el, etype){
      if (el.fireEvent) {
        el.fireEvent('on' + etype);
      } else {
        var evObj = document.createEvent('Events');
        evObj.initEvent(etype, true, false);
        el.dispatchEvent(evObj);
      }
    }

function showPdf(){
  eventFire(document.getElementById('picToClick'), 'click');
}

HTML Code

<img id="picToClick" data-toggle="modal" data-target="#pdfModal" src="img/Adobe-icon.png" ng-hide="1===1">
  <button onclick="showPdf()">Click me</button>

creating list of objects in Javascript

Going off of tbradley22's answer, but using .map instead:

var a = ["car", "bike", "scooter"];
a.map(function(entry) {
    var singleObj = {};
    singleObj['type'] = 'vehicle';
    singleObj['value'] = entry;
    return singleObj;
});

How to change the style of a DatePicker in android?

As AlertDialog.THEME attributes are deprecated, while creating DatePickerDialog you should pass one of these parameters for int themeResId

  • android.R.style.Theme_DeviceDefault_Dialog_Alert
  • android.R.style.Theme_DeviceDefault_Light_Dialog_Alert
  • android.R.style.Theme_Material_Light_Dialog_Alert
  • android.R.style.Theme_Material_Dialog_Alert

Angular2 RC5: Can't bind to 'Property X' since it isn't a known property of 'Child Component'

There are multiple possible causes for this error:

1) When you put the property 'x' inside brackets you are trying to bind to it. Therefore first thing to check is if the property 'x' is defined in your component with an Input() decorator

Your html file:

<body [x]="...">

Your class file:

export class YourComponentClass {

  @Input()
  x: string;
  ...
}

(make sure you also have the parentheses)

2) Make sure you registered your component/directive/pipe classes in NgModule:

@NgModule({
  ...
  declarations: [
    ...,
    YourComponentClass
  ],
  ...
})

See https://angular.io/guide/ngmodule#declare-directives for more details about declare directives.

3) Also happens if you have a typo in your angular directive. For example:

<div *ngif="...">
     ^^^^^

Instead of:

<div *ngIf="...">

This happens because under the hood angular converts the asterisk syntax to:

<div [ngIf]="...">

Axios get access to response header fields

In case of CORS requests, browsers can only access the following response headers by default:

  • Cache-Control
  • Content-Language
  • Content-Type
  • Expires
  • Last-Modified
  • Pragma

If you would like your client app to be able to access other headers, you need to set the Access-Control-Expose-Headers header on the server:

Access-Control-Expose-Headers: Access-Token, Uid

How do I completely uninstall Node.js, and reinstall from beginning (Mac OS X)

Apparently, there was a /Users/myusername/local folder that contained a include with node and lib with node and node_modules. How and why this was created instead of in my /usr/local folder, I do not know.

Deleting these local references fixed the phantom v0.6.1-pre. If anyone has an explanation, I'll choose that as the correct answer.

EDIT:

You may need to do the additional instructions as well:

sudo rm -rf /usr/local/{lib/node{,/.npm,_modules},bin,share/man}/{npm*,node*,man1/node*}

which is the equivalent of (same as above)...

sudo rm -rf /usr/local/bin/npm /usr/local/share/man/man1/node* /usr/local/lib/dtrace/node.d ~/.npm ~/.node-gyp 

or (same as above) broken down...

To completely uninstall node + npm is to do the following:

  1. go to /usr/local/lib and delete any node and node_modules
  2. go to /usr/local/include and delete any node and node_modules directory
  3. if you installed with brew install node, then run brew uninstall node in your terminal
  4. check your Home directory for any local or lib or include folders, and delete any node or node_modules from there
  5. go to /usr/local/bin and delete any node executable

You may also need to do:

sudo rm -rf /opt/local/bin/node /opt/local/include/node /opt/local/lib/node_modules
sudo rm -rf /usr/local/bin/npm /usr/local/share/man/man1/node.1 /usr/local/lib/dtrace/node.d

Additionally, NVM modifies the PATH variable in $HOME/.bashrc, which must be reverted manually.

Then download nvm and follow the instructions to install node. The latest versions of node come with npm, I believe, but you can also reinstall that as well.

react hooks useEffect() cleanup for only componentWillUnmount?

useEffect are isolated within its own scope and gets rendered accordingly. Image from https://reactjs.org/docs/hooks-custom.html

enter image description here

Bootstrap Modal Backdrop Remaining

Using the code below continuously adds 7px padding on the body element every time you open and close a modal.

$('modalId').modal('hide');
$('body').removeClass('modal-open');
$('.modal-backdrop').remove();`

For those who still use Bootstrap 3, here is a hack'ish workaround.

$('#modalid').modal('hide');
$('.modal-backdrop').hide();
document.body.style.paddingRight = '0'
document.getElementsByTagName("body")[0].style.overflowY = "auto";

How to convert Set to Array?

via https://speakerdeck.com/anguscroll/es6-uncensored by Angus Croll

It turns out, we can use spread operator:

var myArr = [...mySet];

Or, alternatively, use Array.from:

var myArr = Array.from(mySet);

How do I make a LinearLayout scrollable?

You cannot make a LinearLayout scrollable because it is not a scrollable container.

Only scrollable containers such as ScrollView, HorizontalScrollView, ListView, GridView, ExpandableListView can be made scrollable.

I suggest you place your LinearLayout inside a ScrollView which will by default show vertical scrollbars if there is enough content to scroll.

<?xml version="1.0" encoding="utf-8"?>
<ScrollView ...>

    <LinearLayout ...>

        ...
        ...

    </LinearLayout>

</ScrollView>

Note : ScrollView takes only one view as its child. So better that child view be a Linear Layout

How do I trim whitespace from a string?

This will remove all leading and trailing whitespace in myString:

myString.strip()

Using awk to print all columns from the nth to the last

Awk examples looks complex here, here is simple Bash shell syntax:

command | while read -a cols; do echo ${cols[@]:1}; done

Where 1 is your nth column counting from 0.


Example

Given this content of file (in.txt):

c1
c1 c2
c1 c2 c3
c1 c2 c3 c4
c1 c2 c3 c4 c5

here is the output:

$ while read -a cols; do echo ${cols[@]:1}; done < in.txt 

c2
c2 c3
c2 c3 c4
c2 c3 c4 c5

Windows equivalent of OS X Keychain?

If you are on windows got to control pannel -> windows Credentials

How can I show and hide elements based on selected option with jQuery?

<script>  
$(document).ready(function(){
    $('#colorselector').on('change', function() {
      if ( this.value == 'red')
      {
        $("#divid").show();
      }
      else
      {
        $("#divid").hide();
      }
    });
});
</script>

Do like this for every value

MongoDB: Server has startup warnings ''Access control is not enabled for the database''

Mongodb v3.4

You need to do the following to create a secure database:

Make sure the user starting the process has permissions and that the directories exist (/data/db in this case).

1) Start MongoDB without access control.

mongod --port 27017 --dbpath /data/db

2) Connect to the instance.

mongo --port 27017

3) Create the user administrator (in the admin authentication database).

use admin
db.createUser(
  {
    user: "myUserAdmin",
    pwd: "abc123",
    roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
  }
)

4) Re-start the MongoDB instance with access control.

mongod --auth --port 27017 --dbpath /data/db

5) Connect and authenticate as the user administrator.

mongo --port 27017 -u "myUserAdmin" -p "abc123" --authenticationDatabase "admin"

6) Create additional users as needed for your deployment (e.g. in the test authentication database).

use test
db.createUser(
  {
    user: "myTester",
    pwd: "xyz123",
    roles: [ { role: "readWrite", db: "test" },
             { role: "read", db: "reporting" } ]
  }
)

7) Connect and authenticate as myTester.

mongo --port 27017 -u "myTester" -p "xyz123" --authenticationDatabase "test"

I basically just explained the short version of the official docs here: https://docs.mongodb.com/master/tutorial/enable-authentication/

Call child component method from parent class - Angular

Angular – Call Child Component’s Method in Parent Component’s Template

You have ParentComponent and ChildComponent that looks like this.

parent.component.html

enter image description here

parent.component.ts

import {Component} from '@angular/core';

@Component({
  selector: 'app-parent',
  templateUrl: './parent.component.html',
  styleUrls: ['./parent.component.css']
})
export class ParentComponent {
  constructor() {
  }
}

child.component.html

<p>
  This is child
</p>

child.component.ts

import {Component} from '@angular/core';

@Component({
  selector: 'app-child',
  templateUrl: './child.component.html',
  styleUrls: ['./child.component.css']
})
export class ChildComponent {
  constructor() {
  }

  doSomething() {
    console.log('do something');
  }
}

When serve, it looks like this:

enter image description here

When user focus on ParentComponent’s input element, you want to call ChildComponent’s doSomething() method.

Simply do this:

  1. Give app-child selector in parent.component.html a DOM variable name (prefix with # – hashtag), in this case we call it appChild.
  2. Assign expression value (of the method you want to call) to input element’s focus event.

enter image description here

The result:

enter image description here

Connect with SSH through a proxy

@rogerdpack for windows platform it is really hard to find a nc.exe with -X(http_proxy), however, I have found nc can be replaced by ncat, full example as follows:

Host github.com
     HostName github.com
         #ProxyCommand nc -X connect -x 127.0.0.1:1080 %h %p
         ProxyCommand ncat --proxy 127.0.0.1:1080 %h %p
     User git
     Port 22
     IdentityFile D:\Users\Administrator\.ssh\github_key

and ncat with --proxy can do a perfect work

How to get root directory in yii2

Use "getAlias" in Yii2

   \Yii::getAlias('@webroot')

Get exit code for command in bash/ksh

Below is the fixed code:

#!/bin/ksh
safeRunCommand() {
  typeset cmnd="$*"
  typeset ret_code

  echo cmnd=$cmnd
  eval $cmnd
  ret_code=$?
  if [ $ret_code != 0 ]; then
    printf "Error : [%d] when executing command: '$cmnd'" $ret_code
    exit $ret_code
  fi
}

command="ls -l | grep p"
safeRunCommand "$command"

Now if you look into this code few things that I changed are:

  • use of typeset is not necessary but a good practice. It make cmnd and ret_code local to safeRunCommand
  • use of ret_code is not necessary but a good practice to store return code in some variable (and store it ASAP) so that you can use it later like I did in printf "Error : [%d] when executing command: '$command'" $ret_code
  • pass the command with quotes surrounding the command like safeRunCommand "$command". If you dont then cmnd will get only the value ls and not ls -l. And it is even more important if your command contains pipes.
  • you can use typeset cmnd="$*" instead of typeset cmnd="$1" if you want to keep the spaces. You can try with both depending upon how complex is your command argument.
  • eval is used to evaluate so that command containing pipes can work fine

NOTE: Do remember some commands give 1 as return code even though there is no error like grep. If grep found something it will return 0 else 1.

I had tested with KSH/BASH. And it worked fine. Let me know if u face issues running this.

How to COUNT rows within EntityFramework without loading contents?

Well, even the SELECT COUNT(*) FROM Table will be fairly inefficient, especially on large tables, since SQL Server really can't do anything but do a full table scan (clustered index scan).

Sometimes, it's good enough to know an approximate number of rows from the database, and in such a case, a statement like this might suffice:

SELECT 
    SUM(used_page_count) * 8 AS SizeKB,
    SUM(row_count) AS [RowCount], 
    OBJECT_NAME(OBJECT_ID) AS TableName
FROM 
    sys.dm_db_partition_stats
WHERE 
    OBJECT_ID = OBJECT_ID('YourTableNameHere')
    AND (index_id = 0 OR index_id = 1)
GROUP BY 
    OBJECT_ID

This will inspect the dynamic management view and extract the number of rows and the table size from it, given a specific table. It does so by summing up the entries for the heap (index_id = 0) or the clustered index (index_id = 1).

It's quick, it's easy to use, but it's not guaranteed to be 100% accurate or up to date. But in many cases, this is "good enough" (and put much less burden on the server).

Maybe that would work for you, too? Of course, to use it in EF, you'd have to wrap this up in a stored proc or use a straight "Execute SQL query" call.

Marc

What are the different NameID format used for?

About this I think you can reference to http://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-tech-overview-2.0.html.

Here're my understandings about this, with the Identity Federation Use Case to give a details for those concepts:

  • Persistent identifiers-

IdP provides the Persistent identifiers, they are used for linking to the local accounts in SPs, but they identify as the user profile for the specific service each alone. For example, the persistent identifiers are kind of like : johnForAir, jonhForCar, johnForHotel, they all just for one specified service, since it need to link to its local identity in the service.

  • Transient identifiers-

Transient identifiers are what IdP tell the SP that the users in the session have been granted to access the resource on SP, but the identities of users do not offer to SP actually. For example, The assertion just like “Anonymity(Idp doesn’t tell SP who he is) has the permission to access /resource on SP”. SP got it and let browser to access it, but still don’t know Anonymity' real name.

  • unspecified identifiers-

The explanation for it in the spec is "The interpretation of the content of the element is left to individual implementations". Which means IdP defines the real format for it, and it assumes that SP knows how to parse the format data respond from IdP. For example, IdP gives a format data "UserName=XXXXX Country=US", SP get the assertion, and can parse it and extract the UserName is "XXXXX".

What are the rules for JavaScript's automatic semicolon insertion (ASI)?

The most contextual description of JavaScript's Automatic Semicolon Insertion I have found comes from a book about Crafting Interpreters.

JavaScript’s “automatic semicolon insertion” rule is the odd one. Where other languages assume most newlines are meaningful and only a few should be ignored in multi-line statements, JS assumes the opposite. It treats all of your newlines as meaningless whitespace unless it encounters a parse error. If it does, it goes back and tries turning the previous newline into a semicolon to get something grammatically valid.

He goes on to describe it as you would code smell.

This design note would turn into a design diatribe if I went into complete detail about how that even works, much less all the various ways that that is a bad idea. It’s a mess. JavaScript is the only language I know where many style guides demand explicit semicolons after every statement even though the language theoretically lets you elide them.

Facebook Graph API error code list

I was looking for the same thing and I just found this list

https://developers.facebook.com/docs/reference/api/errors/

How to use RecyclerView inside NestedScrollView?

This is what working for me

<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</android.support.v4.widget.NestedScrollView>

How can I get an int from stdio in C?

The solution is quite simple ... you're reading getchar() which gives you the first character in the input buffer, and scanf just parsed it (really don't know why) to an integer, if you just forget the getchar for a second, it will read the full buffer until a newline char.

printf("> ");
int x;
scanf("%d", &x);
printf("got the number: %d", x);

Outputs

> [prompt expecting input, lets write:] 1234 [Enter]
got the number: 1234

What is the purpose of mvnw and mvnw.cmd files?

By far the best option nowadays would be using a maven container as a builder tool. A mvn.sh script like this would be enough:

#!/bin/bash
docker run --rm -ti \
 -v $(pwd):/opt/app \
 -w /opt/app \
 -e TERM=xterm \
 -v $HOME/.m2:/root/.m2 \
 maven mvn "$@"

How can I center text (horizontally and vertically) inside a div block?

Add the line display: table-cell; to your CSS content for that div.

Only table cells support the vertical-align: middle;, but you can give that [table-cell] definition to the div...

A live example is here: http://jsfiddle.net/tH2cc/

div{
    height: 90px;
    width: 90px;
    text-align: center;
    border: 1px solid silver;
    display: table-cell; // This says treat this element like a table cell
    vertical-align:middle; // Now we can center vertically like in a TD
}

Preprocessor check if multiple defines are not defined

#if !defined(MANUF) || !defined(SERIAL) || !defined(MODEL)

Git "error: The branch 'x' is not fully merged"

I did not have the upstream branch on my local git. I had created a local branch from master, git checkout -b mybranch . I created a branch with bitbucket GUI on the upstream git and pushed my local branch (mybranch) to that upstream branch. Once I did a git fetch on my local git to retrieve the upstream branch, I could do a git branch -d mybranch.

Map enum in JPA with fixed values?

Possibly close related code of Pascal

@Entity
@Table(name = "AUTHORITY_")
public class Authority implements Serializable {

    public enum Right {
        READ(100), WRITE(200), EDITOR(300);

        private Integer value;

        private Right(Integer value) {
            this.value = value;
        }

        // Reverse lookup Right for getting a Key from it's values
        private static final Map<Integer, Right> lookup = new HashMap<Integer, Right>();
        static {
            for (Right item : Right.values())
                lookup.put(item.getValue(), item);
        }

        public Integer getValue() {
            return value;
        }

        public static Right getKey(Integer value) {
            return lookup.get(value);
        }

    };

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "AUTHORITY_ID")
    private Long id;

    @Column(name = "RIGHT_ID")
    private Integer rightId;

    public Right getRight() {
        return Right.getKey(this.rightId);
    }

    public void setRight(Right right) {
        this.rightId = right.getValue();
    }

}

How to execute an external program from within Node.js?

exec has memory limitation of buffer size of 512k. In this case it is better to use spawn. With spawn one has access to stdout of executed command at run time

var spawn = require('child_process').spawn;
var prc = spawn('java',  ['-jar', '-Xmx512M', '-Dfile.encoding=utf8', 'script/importlistings.jar']);

//noinspection JSUnresolvedFunction
prc.stdout.setEncoding('utf8');
prc.stdout.on('data', function (data) {
    var str = data.toString()
    var lines = str.split(/(\r?\n)/g);
    console.log(lines.join(""));
});

prc.on('close', function (code) {
    console.log('process exit code ' + code);
});

Specifying colClasses in the read.csv

If we combine what @Hendy and @Oddysseus Ithaca contributed, we get cleaner and a more general (i.e., adaptable?) chunk of code.

    data <- read.csv("test.csv", head = F, colClasses = c(V36 = "character", V38 = "character"))                        

Adding default parameter value with type hint in Python

Your second way is correct.

def foo(opts: dict = {}):
    pass

print(foo.__annotations__)

this outputs

{'opts': <class 'dict'>}

It's true that's it's not listed in PEP 484, but type hints are an application of function annotations, which are documented in PEP 3107. The syntax section makes it clear that keyword arguments works with function annotations in this way.

I strongly advise against using mutable keyword arguments. More information here.

"unrecognized import path" with go get

$ unset GOROOT worked for me. As most answers suggest your GOROOT is invalid.

In angular $http service, How can I catch the "status" of error?

Your arguments are incorrect, error doesn't return an object containing status and message, it passed them as separate parameters in the order described below.

Taken from the angular docs:

  • data – {string|Object} – The response body transformed with the transform functions.
  • status – {number} – HTTP status code of the response.
  • headers – {function([headerName])} – Header getter function.
  • config – {Object} – The configuration object that was used to generate the request.
  • statusText – {string} – HTTP status text of the response.

So you'd need to change your code to:

$http.get(dataUrl)
    .success(function (data){
        $scope.data.products = data;
    })
    .error(function (error, status){
        $scope.data.error = { message: error, status: status};
        console.log($scope.data.error.status); 
  }); 

Obviously, you don't have to create an object representing the error, you could just create separate scope properties but the same principle applies.

CSS to make HTML page footer stay at bottom of the page with a minimum height, but not overlap the page

I have used in my many projects and never got any single issue :)

for your reference, Code are in snippet

_x000D_
_x000D_
* {_x000D_
 margin: 0;_x000D_
}_x000D_
html, body {_x000D_
 height: 100%;_x000D_
}_x000D_
.wrapper {_x000D_
 min-height: 100%;_x000D_
 height: auto !important; /* This line and the next line are not necessary unless you need IE6 support */_x000D_
 height: 100%;_x000D_
 margin: 0 auto -50px; /* the bottom margin is the negative value of the footer's height */_x000D_
  background:green;_x000D_
}_x000D_
.footer, .push {_x000D_
 height: 50px; /* .push must be the same height as .footer */_x000D_
}_x000D_
_x000D_
.footer{_x000D_
  background:gold;_x000D_
  }
_x000D_
<html>_x000D_
<head>_x000D_
<meta charset="utf-8">_x000D_
<title>Untitled Document</title>_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
  <div class="wrapper">_x000D_
    Content Area_x000D_
    </div>_x000D_
  _x000D_
  <div class="push">_x000D_
    </div>_x000D_
  _x000D_
  <div class="footer">_x000D_
    Footer Area_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

How do I force a favicon refresh?

This works for Chrome:

  • on Mac: delete file

    ${user.home}/Library/Application Support/Google/Chrome/Default/Favicons

  • on Windows: delete files

    C:\Users[username]\AppData\Local\Google\Chrome\User Data\Default\Favicons C:\Users[username]\AppData\Local\Google\Chrome\User Data\Default\Favicons-journal

source

How to convert buffered image to image and vice-versa?

BufferedImage is a subclass of Image. You don't need to do any conversion.

How to use concerns in Rails 4

I felt most of the examples here demonstrated the power of module rather than how ActiveSupport::Concern adds value to module.

Example 1: More readable modules.

So without concerns this how a typical module will be.

module M
  def self.included(base)
    base.extend ClassMethods
    base.class_eval do
      scope :disabled, -> { where(disabled: true) }
    end
  end

  def instance_method
    ...
  end

  module ClassMethods
    ...
  end
end

After refactoring with ActiveSupport::Concern.

require 'active_support/concern'

module M
  extend ActiveSupport::Concern

  included do
    scope :disabled, -> { where(disabled: true) }
  end

  class_methods do
    ...
  end

  def instance_method
    ...
  end
end

You see instance methods, class methods and included block are less messy. Concerns will inject them appropriately for you. That's one advantage of using ActiveSupport::Concern.


Example 2: Handle module dependencies gracefully.

module Foo
  def self.included(base)
    base.class_eval do
      def self.method_injected_by_foo_to_host_klass
        ...
      end
    end
  end
end

module Bar
  def self.included(base)
    base.method_injected_by_foo_to_host_klass
  end
end

class Host
  include Foo # We need to include this dependency for Bar
  include Bar # Bar is the module that Host really needs
end

In this example Bar is the module that Host really needs. But since Bar has dependency with Foo the Host class have to include Foo (but wait why does Host want to know about Foo? Can it be avoided?).

So Bar adds dependency everywhere it goes. And order of inclusion also matters here. This adds lot of complexity/dependency to huge code base.

After refactoring with ActiveSupport::Concern

require 'active_support/concern'

module Foo
  extend ActiveSupport::Concern
  included do
    def self.method_injected_by_foo_to_host_klass
      ...
    end
  end
end

module Bar
  extend ActiveSupport::Concern
  include Foo

  included do
    self.method_injected_by_foo_to_host_klass
  end
end

class Host
  include Bar # It works, now Bar takes care of its dependencies
end

Now it looks simple.

If you are thinking why can't we add Foo dependency in Bar module itself? That won't work since method_injected_by_foo_to_host_klass have to be injected in a class that's including Bar not on Bar module itself.

Source: Rails ActiveSupport::Concern

Java Constructor Inheritance

A derived class is not the the same class as its base class and you may or may not care whether any members of the base class are initialized at the time of the construction of the derived class. That is a determination made by the programmer not by the compiler.

javascript: Disable Text Select

Simple Copy this text and put on the before </body>

function disableselect(e) {
  return false
}

function reEnable() {
  return true
}

document.onselectstart = new Function ("return false")

if (window.sidebar) {
  document.onmousedown = disableselect
  document.onclick = reEnable
}

How to get all Windows service names starting with a common word?

Using PowerShell, you can use the following

Get-Service | Where-Object {$_.displayName.StartsWith("NATION-")} | Select name

This will show a list off all services which displayname starts with "NATION-".

You can also directly stop or start the services;

Get-Service | Where-Object {$_.displayName.StartsWith("NATION-")} | Stop-Service
Get-Service | Where-Object {$_.displayName.StartsWith("NATION-")} | Start-Service

or simply

Get-Service | Where-Object {$_.displayName.StartsWith("NATION-")} | Restart-Service

How do I get the current year using SQL on Oracle?

Another option is:

SELECT *
  FROM TABLE
 WHERE EXTRACT( YEAR FROM date_field) = EXTRACT(YEAR FROM sysdate) 

How to split comma separated string using JavaScript?

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_x000D_
var result;_x000D_
result = "1,2,3".split(","); _x000D_
console.log(result);
_x000D_
_x000D_
_x000D_

More info on W3Schools describing the String Split function.

Convert String to System.IO.Stream

Try this:

// convert string to stream
byte[] byteArray = Encoding.UTF8.GetBytes(contents);
//byte[] byteArray = Encoding.ASCII.GetBytes(contents);
MemoryStream stream = new MemoryStream(byteArray);

and

// convert stream to string
StreamReader reader = new StreamReader(stream);
string text = reader.ReadToEnd();

LaTeX package for syntax highlighting of code in various languages

LGrind does this. It's a mature LaTeX package that's been around since adam was a cowboy and has support for many programming languages.

React with ES7: Uncaught TypeError: Cannot read property 'state' of undefined

You have to bind your event handlers to correct context (this):

onChange={this.setAuthorState.bind(this)}

Print all key/value pairs in a Java ConcurrentHashMap

The ConcurrentHashMap is very similar to the HashMap class, except that ConcurrentHashMap offers internally maintained concurrency. It means you do not need to have synchronized blocks when accessing ConcurrentHashMap in multithreaded application.

To get all key-value pairs in ConcurrentHashMap, below code which is similar to your code works perfectly:

//Initialize ConcurrentHashMap instance
ConcurrentHashMap<String, Integer> m = new ConcurrentHashMap<String, Integer>();

//Print all values stored in ConcurrentHashMap instance
for each (Entry<String, Integer> e : m.entrySet()) {
  System.out.println(e.getKey()+"="+e.getValue());
}

Above code is reasonably valid in multi-threaded environment in your application. The reason, I am saying 'reasonably valid' is that, above code yet provides thread safety, still it can decrease the performance of application.

Hope this helps you.

How can I add reflection to a C++ application?

If you declare a pointer to a function like this:

int (*func)(int a, int b);

You can assign a place in memory to that function like this (requires libdl and dlopen)

#include <dlfcn.h>

int main(void)
{
    void *handle;
    char *func_name = "bla_bla_bla";
    handle = dlopen("foo.so", RTLD_LAZY);
    *(void **)(&func) = dlsym(handle, func_name);
    return func(1,2);
}

To load a local symbol using indirection, you can use dlopen on the calling binary (argv[0]).

The only requirement for this (other than dlopen(), libdl, and dlfcn.h) is knowing the arguments and type of the function.

Unix command to find lines common in two files

Maybe you mean comm ?

Compare sorted files FILE1 and FILE2 line by line.

With no options, produce three-column output. Column one contains lines unique to FILE1, column two contains lines unique to FILE2, and column three contains lines common to both files.

The secret in finding these information are the info pages. For GNU programs, they are much more detailed than their man-pages. Try info coreutils and it will list you all the small useful utils.

How to get commit history for just one branch?

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

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

How to pass optional parameters while omitting some other optional parameters?

you can use optional variable by ? or if you have multiple optional variable by ..., example:

function details(name: string, country="CA", address?: string, ...hobbies: string) {
    // ...
}

In the above:

  • name is required
  • country is required and has a default value
  • address is optional
  • hobbies is an array of optional params

Error CS1705: "which has a higher version than referenced assembly"

for SharePoint, make sure that under your root folder you don't have a "bin" folder with your DLL's, if so just delete it. (and change "Copy Local" to false in VS).

How do synchronized static methods work in Java and can I use it for loading Hibernate entities?

If it is something to do with the data in your database, why not utilize database isolation locking to achieve?

Error: Unable to run mksdcard SDK tool

This is what worked for me

When I tried the Accepted ans my Android Studio hangs on start-up

This is the link

http://tools.android.com/tech-docs/linux-32-bit-libraries

and This is the Command

$ sudo apt-get install libc6:i386 libncurses5:i386 libstdc++6:i386 lib32z1

Hide Utility Class Constructor : Utility classes should not have a public or default constructor

If this class is only a utility class, you should make the class final and define a private constructor:

public final class FilePathHelper {

   private FilePathHelper() {
      //not called
   }
}

This prevents the default parameter-less constructor from being used elsewhere in your code. Additionally, you can make the class final, so that it can't be extended in subclasses, which is a best practice for utility classes. Since you declared only a private constructor, other classes wouldn't be able to extend it anyway, but it is still a best practice to mark the class as final.

How to bind WPF button to a command in ViewModelBase?

 <Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Button Command="{Binding ClickCommand}" Width="100" Height="100" Content="wefwfwef"/>
</Grid>

the code behind for the window:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModelBase();
    }
}

The ViewModel:

public class ViewModelBase
{
    private ICommand _clickCommand;
    public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), ()=> CanExecute));
        }
    }
     public bool CanExecute
     {
        get
        {
            // check if executing is allowed, i.e., validate, check if a process is running, etc. 
            return true/false;
        }
     }

    public void MyAction()
    {

    }
}

Command Handler:

 public class CommandHandler : ICommand
{
    private Action _action;
    private Func<bool> _canExecute;

    /// <summary>
    /// Creates instance of the command handler
    /// </summary>
    /// <param name="action">Action to be executed by the command</param>
    /// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
    public CommandHandler(Action action, Func<bool> canExecute)
    {
        _action = action;
        _canExecute = canExecute;
    }

    /// <summary>
    /// Wires CanExecuteChanged event 
    /// </summary>
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    /// <summary>
    /// Forcess checking if execute is allowed
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool CanExecute(object parameter)
    {
        return _canExecute.Invoke();
    }

    public void Execute(object parameter)
    {
        _action();
    }
}

I hope this will give you the idea.

SQLite3 database or disk is full / the database disk image is malformed

while using Google App Engine, i had this problem. For some reason i did following since then Google App Engine was never starting.

$ echo '' > /tmp/appengine.apprtc.root/*.db

To fix it i required to do manually:

$ sqlite3 datastore.db
sqlite> begin immediate;
<press CTRL+Z>
$ cp datastore.db logs.db

And then run the Google App Engine with flag:

$ dev_appserver.py --clear_datastore --clear_search_index

after that it finally worked.

Convert Newtonsoft.Json.Linq.JArray to a list of specific object type

Just call array.ToObject<List<SelectableEnumItem>>() method. It will return what you need.

Documentation: Convert JSON to a Type

What's the fastest way to convert String to Number in JavaScript?

I find that num * 1 is simple, clear, and works for integers and floats...

Add custom headers to WebView resource requests - android

I came accross the same problem and solved.

As said before you need to create your custom WebViewClient and override the shouldInterceptRequest method.

WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request)

That method should issue a webView.loadUrl while returning an "empty" WebResourceResponse.

Something like this:

@Override
public boolean shouldInterceptRequest(WebView view, WebResourceRequest request) {

    // Check for "recursive request" (are yor header set?)
    if (request.getRequestHeaders().containsKey("Your Header"))
        return null;

    // Add here your headers (could be good to import original request header here!!!)
    Map<String, String> customHeaders = new HashMap<String, String>();
    customHeaders.put("Your Header","Your Header Value");
    view.loadUrl(url, customHeaders);

    return new WebResourceResponse("", "", null);
}

Open a webpage in the default browser

This worked perfectly for me. Since this is for personal use, I used Firefox as my browser.

 Dim url As String
    url = "http://www.google.com"
    Process.Start("Firefox", url)

Partly JSON unmarshal into a map in Go

Further to Stephen Weinberg's answer, I have since implemented a handy tool called iojson, which helps to populate data to an existing object easily as well as encoding the existing object to a JSON string. A iojson middleware is also provided to work with other middlewares. More examples can be found at https://github.com/junhsieh/iojson

Example:

func main() {
    jsonStr := `{"Status":true,"ErrArr":[],"ObjArr":[{"Name":"My luxury car","ItemArr":[{"Name":"Bag"},{"Name":"Pen"}]}],"ObjMap":{}}`

    car := NewCar()

    i := iojson.NewIOJSON()

    if err := i.Decode(strings.NewReader(jsonStr)); err != nil {
        fmt.Printf("err: %s\n", err.Error())
    }

    // populating data to a live car object.
    if v, err := i.GetObjFromArr(0, car); err != nil {
        fmt.Printf("err: %s\n", err.Error())
    } else {
        fmt.Printf("car (original): %s\n", car.GetName())
        fmt.Printf("car (returned): %s\n", v.(*Car).GetName())

        for k, item := range car.ItemArr {
            fmt.Printf("ItemArr[%d] of car (original): %s\n", k, item.GetName())
        }

        for k, item := range v.(*Car).ItemArr {
            fmt.Printf("ItemArr[%d] of car (returned): %s\n", k, item.GetName())
        }
    }
}

Sample output:

car (original): My luxury car
car (returned): My luxury car
ItemArr[0] of car (original): Bag
ItemArr[1] of car (original): Pen
ItemArr[0] of car (returned): Bag
ItemArr[1] of car (returned): Pen

Left-pad printf with spaces

If you want exactly 40 spaces before the string then you should just do:

printf("                                        %s\n", myStr );

If that is too dirty, you can do (but it will be slower than manually typing the 40 spaces): printf("%40s%s", "", myStr );

If you want the string to be lined up at column 40 (that is, have up to 39 spaces proceeding it such that the right most character is in column 40) then do this: printf("%40s", myStr);

You can also put "up to" 40 spaces AfTER the string by doing: printf("%-40s", myStr);

Is this how you define a function in jQuery?

No, you can just write the function as:

$(document).ready(function() {
    MyBlah("hello");
});

function MyBlah(blah) {
    alert(blah);
}

This calls the function MyBlah on content ready.

'typeid' versus 'typeof' in C++

C++ language has no such thing as typeof. You must be looking at some compiler-specific extension. If you are talking about GCC's typeof, then a similar feature is present in C++11 through the keyword decltype. Again, C++ has no such typeof keyword.

typeid is a C++ language operator which returns type identification information at run time. It basically returns a type_info object, which is equality-comparable with other type_info objects.

Note, that the only defined property of the returned type_info object has is its being equality- and non-equality-comparable, i.e. type_info objects describing different types shall compare non-equal, while type_info objects describing the same type have to compare equal. Everything else is implementation-defined. Methods that return various "names" are not guaranteed to return anything human-readable, and even not guaranteed to return anything at all.

Note also, that the above probably implies (although the standard doesn't seem to mention it explicitly) that consecutive applications of typeid to the same type might return different type_info objects (which, of course, still have to compare equal).

Get HTML source of WebElement in Selenium WebDriver using Python

And in PHPUnit Selenium test it's like this:

$text = $this->byCssSelector('.some-class-nmae')->attribute('innerHTML');

How to refresh or show immediately in datagridview after inserting?

Only need to fill datagrid again like this:

this.XXXTableAdapter.Fill(this.DataSet.XXX);

If you use automaticlly connect from dataGridView this code create automaticlly in Form_Load()

C# difference between == and Equals()

== and .Equals are both dependent upon the behavior defined in the actual type and the actual type at the call site. Both are just methods / operators which can be overridden on any type and given any behavior the author so desires. In my experience, I find it's common for people to implement .Equals on an object but neglect to implement operator ==. This means that .Equals will actually measure the equality of the values while == will measure whether or not they are the same reference.

When I'm working with a new type whose definition is in flux or writing generic algorithms, I find the best practice is the following

  • If I want to compare references in C#, I use Object.ReferenceEquals directly (not needed in the generic case)
  • If I want to compare values I use EqualityComparer<T>.Default

In some cases when I feel the usage of == is ambiguous I will explicitly use Object.Reference equals in the code to remove the ambiguity.

Eric Lippert recently did a blog post on the subject of why there are 2 methods of equality in the CLR. It's worth the read

How to convert this var string to URL in Swift

in swift 4 to convert to url use URL

let fileUrl = URL.init(fileURLWithPath: filePath)

or

let fileUrl = URL(fileURLWithPath: filePath)

Best way to do Version Control for MS Excel

I found a very simple solution to this question which meets my needs. I add one line to the bottom of all of my macros which exports a *.txt file with the entire macro code each time it is run. The code:

ActiveWorkbook.VBProject.VBComponents("moduleName").Export"C:\Path\To\Spreadsheet\moduleName.txt"

(Found on Tom's Tutorials, which also covers some setup you may need to get this working.)

Since I'll always run the macro whenever I'm working on the code, I'm guaranteed that git will pick up the changes. The only annoying part is that if I need to checkout an earlier version, I have to manually copy/paste from the *.txt into the spreadsheet.

StringIO in Python3

Roman Shapovalov's code should work in Python 3.x as well as Python 2.6/2.7. Here it is again with the complete example:

import io
import numpy
x = "1 3\n 4.5 8"
numpy.genfromtxt(io.BytesIO(x.encode()))

Output:

array([[ 1. ,  3. ],
       [ 4.5,  8. ]])

Explanation for Python 3.x:

  • numpy.genfromtxt takes a byte stream (a file-like object interpreted as bytes instead of Unicode).
  • io.BytesIO takes a byte string and returns a byte stream. io.StringIO, on the other hand, would take a Unicode string and and return a Unicode stream.
  • x gets assigned a string literal, which in Python 3.x is a Unicode string.
  • encode() takes the Unicode string x and makes a byte string out of it, thus giving io.BytesIO a valid argument.

The only difference for Python 2.6/2.7 is that x is a byte string (assuming from __future__ import unicode_literals is not used), and then encode() takes the byte string x and still makes the same byte string out of it. So the result is the same.


Since this is one of SO's most popular questions regarding StringIO, here's some more explanation on the import statements and different Python versions.

Here are the classes which take a string and return a stream:

  • io.BytesIO (Python 2.6, 2.7, and 3.x) - Takes a byte string. Returns a byte stream.
  • io.StringIO (Python 2.6, 2.7, and 3.x) - Takes a Unicode string. Returns a Unicode stream.
  • StringIO.StringIO (Python 2.x) - Takes a byte string or Unicode string. If byte string, returns a byte stream. If Unicode string, returns a Unicode stream.
  • cStringIO.StringIO (Python 2.x) - Faster version of StringIO.StringIO, but can't take Unicode strings which contain non-ASCII characters.

Note that StringIO.StringIO is imported as from StringIO import StringIO, then used as StringIO(...). Either that, or you do import StringIO and then use StringIO.StringIO(...). The module name and class name just happen to be the same. It's similar to datetime that way.

What to use, depending on your supported Python versions:

  • If you only support Python 3.x: Just use io.BytesIO or io.StringIO depending on what kind of data you're working with.

  • If you support both Python 2.6/2.7 and 3.x, or are trying to transition your code from 2.6/2.7 to 3.x: The easiest option is still to use io.BytesIO or io.StringIO. Although StringIO.StringIO is flexible and thus seems preferred for 2.6/2.7, that flexibility could mask bugs that will manifest in 3.x. For example, I had some code which used StringIO.StringIO or io.StringIO depending on Python version, but I was actually passing a byte string, so when I got around to testing it in Python 3.x it failed and had to be fixed.

    Another advantage of using io.StringIO is the support for universal newlines. If you pass the keyword argument newline='' into io.StringIO, it will be able to split lines on any of \n, \r\n, or \r. I found that StringIO.StringIO would trip up on \r in particular.

    Note that if you import BytesIO or StringIO from six, you get StringIO.StringIO in Python 2.x and the appropriate class from io in Python 3.x. If you agree with my previous paragraphs' assessment, this is actually one case where you should avoid six and just import from io instead.

  • If you support Python 2.5 or lower and 3.x: You'll need StringIO.StringIO for 2.5 or lower, so you might as well use six. But realize that it's generally very difficult to support both 2.5 and 3.x, so you should consider bumping your lowest supported version to 2.6 if at all possible.

jQuery: set selected value of dropdown list?

You can select dropdown option value by name

jQuery("#option_id").find("option:contains('Monday')").each(function()
{
 if( jQuery(this).text() == 'Monday' )
 {
  jQuery(this).attr("selected","selected");
  }
});

How to find unused/dead code in java projects

Eclipse can show/highlight code that can't be reached. JUnit can show you code coverage, but you'd need some tests and have to decide if the relevant test is missing or the code is really unused.

How do I create JavaScript array (JSON format) dynamically?

What I do is something just a little bit different from @Chase answer:

var employees = {};

// ...and then:
employees.accounting = new Array();

for (var i = 0; i < someArray.length; i++) {
    var temp_item = someArray[i];

    // Maybe, here make something like:
    // temp_item.name = 'some value'

    employees.accounting.push({
        "firstName" : temp_item.firstName,
        "lastName"  : temp_item.lastName,
        "age"       : temp_item.age
    });
}

And that work form me!

I hope it could be useful for some body else!

How to use both onclick and target="_blank"

Just use window.open():

window.open('Prosjektplan.pdf')

Anyway, what guys are saying on comments is true. You better use <a target="_blank"> instead of click events.

Open another page in php

Use something like header( 'Location: /my-other-page.html' ); to redirect. You can't have sent any other data on the page before you do this though.

Popup window in PHP?

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

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

And this in your body:

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

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

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

-----EDIT-----

To display it using php try this:

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

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

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

How to drop SQL default constraint without knowing its name?

I hope this could be helpful for whom has similar problem . In ObjectExplorer window, select your database=> Tables,=> your table=> Constraints. If the customer is defined on create column time, you can see the default name of constraint including the column name. then use:

ALTER TABLE  yourTableName DROP CONSTRAINT DF__YourTa__NewCo__47127295;

(the constraint name is just an example)

Enable/Disable Anchor Tags using AngularJS

Disclaimer:

The OP has made this comment on another answer:

We can have ngDisabled for buttons or input tags; by using CSS we can make the button to look like anchor tag but that doesn't help much! I was more keen on looking how it can be done using directive approach or angular way of doing it?


You can use a variable inside the scope of your controller to disable the links/buttons according to the last button/link that you've clicked on by using ng-click to set the variable at the correct value and ng-disabled to disable the button when needed according to the value in the variable.

I've updated your Plunker to give you an idea.

But basically, it's something like this:

 <div>
       <button ng-click="create()" ng-disabled="state === 'edit'">CREATE</button><br/>
       <button ng-click="edit()" ng-disabled="state === 'create'">EDIT</button><br/>
       <button href="" ng-click="delete()" ng-disabled="state === 'create' || state === 'edit'">DELETE</button>
    </div>

Lombok is not generating getter and setter

If you are using maven and Eclipse, must be installed manually.

  1. Verify pom

_x000D_
_x000D_
 <dependency>_x000D_
            <groupId>org.projectlombok</groupId>_x000D_
            <artifactId>lombok</artifactId>_x000D_
            <version>1.18.10</version>_x000D_
            <type>jar</type>_x000D_
        </dependency>
_x000D_
_x000D_
_x000D_

  1. go to Maven Dependencies

enter image description here

  1. Right click in the library and Run as Java aplication

enter image description here

  1. Especify location IDE, install and close IDE (Eclipse). enter image description here

Error: Local workspace file ('angular.json') could not be found

Uninstall the old version of Angular cli, and install Angular CLI global:

Update Angular cli global package to the next version, "@angular/compiler-cli": "^6.0.0"

npm uninstall -g @angular/cli
npm cache verify
npm install -g @angular/cli@next

Generate a new project and default application by running the following command:

ng new my-project
cd my-project
ng serve

What is the "-->" operator in C/C++?

There is a space missing between -- and >. x is post decremented, that is, decremented after checking the condition x>0 ?.

How can I generate an apk that can run without server with react-native?

You will have to create a key to sign the apk. Use below to create your key:

 keytool -genkey -v -keystore my-app-key.keystore -alias my-app-alias -keyalg RSA -keysize 2048 -validity 10000

Use a password when prompted

Once the key is generated, use it to generate the installable build:

 react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res/

Generate the build using gradle

 cd android && ./gradlew assembleRelease

Upload the APK to your phone. The -r flag will replace the existing app (if it exists)

adb install -r ./app/build/outputs/apk/app-release-unsigned.apk

A more detailed description is mentioned here: https://facebook.github.io/react-native/docs/signed-apk-android.html

UPDATE: Based on comments by @shashuec and @Fallen

if you get error

ENOENT: no such file or directory, open 'android/app/src/main/assets/index.android.bundle'

run mkdir android/app/src/main/assets

High CPU Utilization in java application - why?

You may be victim of a garbage collection problem.

When your application requires memory and it's getting low on what it's configured to use the garbage collector will run often which consume a lot of CPU cycles. If it can't collect anything your memory will stay low so it will be run again and again. When you redeploy your application the memory is cleared and the garbage collection won't happen more than required so the CPU utilization stays low until it's full again.

You should check that there is no possible memory leak in your application and that it's well configured for memory (check the -Xmx parameter, see What does Java option -Xmx stand for?)

Also, what are you using as web framework? JSF relies a lot on sessions and consumes a lot of memory, consider being stateless at most!

How can I call controller/view helper methods from the console in Ruby on Rails?

Inside any controller action or view, you can invoke the console by calling the console method.

For example, in a controller:

class PostsController < ApplicationController
  def new
    console
    @post = Post.new
  end
end

Or in a view:

<% console %>

<h2>New Post</h2>

This will render a console inside your view. You don't need to care about the location of the console call; it won't be rendered on the spot of its invocation but next to your HTML content.

See: http://guides.rubyonrails.org/debugging_rails_applications.html

Custom exception type

Yes. You can throw anything you want: integers, strings, objects, whatever. If you want to throw an object, then simply create a new object, just as you would create one under other circumstances, and then throw it. Mozilla's Javascript reference has several examples.

How to keep a VMWare VM's clock in sync?

I'll answer for Windows guests. If you have VMware Tools installed, then the taskbar's notification area (near the clock) has an icon for VMware Tools. Double-click that and set your options.

If you don't have VMware Tools installed, you can still set the clock's option for internet time to sync with some NTP server. If your physical machine serves the NTP protocol to your guest machines then you can get that done with host-only networking. Otherwise you'll have to let your guests sync with a genuine NTP server out on the internet, for example time.windows.com.

Can I change the color of Font Awesome's icon color?

You can change the Font Awesome's icon color with the bootstrap class

use

text-color

example

text-white

Jquery $.ajax fails in IE on cross domain calls

Note, adding

$.support.cors = true;

was sufficient to force $.ajax calls to work on IE8

How to do multiple arguments to map function where one remains the same in python?

Map can contain multiple arguments, the standard way is

map(add, a, b)

In your question, it should be

map(add, a, [2]*len(a))

Error message "No exports were found that match the constraint contract name"

Clearing the folders didn't work for me. So I went to 'Programs and Features' and used the change button to startup the Visual Studio 2013 setup.

In the setup I choose the repair function and that fixed the problem for me.

How to do Select All(*) in linq to sql

I often need to retrieve 'all' columns, except a few. so Select(x => x) does not work for me.

LINQPad's editor can auto-expand * to all columns.

enter image description here

after select '* all', LINQPad expands *, then I can remove not-needed columns.

enter image description here

Re-ordering factor levels in data frame

Assuming your dataframe is mydf:

mydf$task <- factor(mydf$task, levels = c("up", "down", "left", "right", "front", "back"))

Google drive limit number of download

Sure Google has a limit of downloads so that you don't abuse the system. These are the limits if you are using Gmail:

The following limits apply for Google Apps for Business or Education editions. Limits for domains during trial are lower. These limits may change without notice in order to protect Google’s infrastructure.

Bandwidth limits

Limit                          Per hour            Per day
Download via web client        750 MB              1250 MB
Upload via web client          300 MB              500 MB
POP and IMAP bandwidth limits

Limit                Per day
Download via IMAP    2500 MB
Download via POP     1250 MB
Upload via IMAP      500 MB

check out this link

JavaScript error: "is not a function"

For more generic advice on debugging this kind of problem MDN have a good article TypeError: "x" is not a function:

It was attempted to call a value like a function, but the value is not actually a function. Some code expects you to provide a function, but that didn't happen.

Maybe there is a typo in the function name? Maybe the object you are calling the method on does not have this function? For example, JavaScript objects have no map function, but JavaScript Array object do.

Basically the object (all functions in js are also objects) does not exist where you think it does. This could be for numerous reasons including(not an extensive list):

  • Missing script library
  • Typo
  • The function is within a scope that you currently do not have access to, e.g.:

_x000D_
_x000D_
var x = function(){_x000D_
   var y = function() {_x000D_
      alert('fired y');_x000D_
   }_x000D_
};_x000D_
    _x000D_
//the global scope can't access y because it is closed over in x and not exposed_x000D_
//y is not a function err triggered_x000D_
x.y();
_x000D_
_x000D_
_x000D_

  • Your object/function does not have the function your calling:

_x000D_
_x000D_
var x = function(){_x000D_
   var y = function() {_x000D_
      alert('fired y');_x000D_
   }_x000D_
};_x000D_
    _x000D_
//z is not a function error (as above) triggered_x000D_
x.z();
_x000D_
_x000D_
_x000D_

DateTime format to SQL format using C#

   DateTime date1 = new DateTime();

    date1 = Convert.ToDateTime(TextBox1.Text);
    Label1.Text = (date1.ToLongTimeString()); //11:00 AM
    Label2.Text = date1.ToLongDateString(); //Friday, November 1, 2019;
    Label3.Text = date1.ToString();
    Label4.Text = date1.ToShortDateString();
    Label5.Text = date1.ToShortTimeString();

What are access specifiers? Should I inherit with private, protected or public?

The explanation from Scott Meyers in Effective C++ might help understand when to use them:

Public inheritance should model "is-a relationship," whereas private inheritance should be used for "is-implemented-in-terms-of" - so you don't have to adhere to the interface of the superclass, you're just reusing the implementation.

Excel: Searching for multiple terms in a cell

This will do it for you:

=IF(OR(ISNUMBER(SEARCH("Gingrich",C3)),ISNUMBER(SEARCH("Obama",C3))),"1","")

Given this function in the column to the right of the names (which are in column C), the result is:

Romney  
Gingrich    1
Obama       1

JSON for List of int

Assuming your ints are 0, 375, 668,5 and 6:

{
    "Id": "610",
    "Name": "15",
    "Description": "1.99",
    "ItemModList": [
                       0,
                       375,
                       668,
                       5,
                       6
                   ]
}

I suggest that you change "Id": "610" to "Id": 610 since it is a integer/long and not a string. You can read more about the JSON format and examples here http://json.org/

Objective-C declared @property attributes (nonatomic, copy, strong, weak)

This link has the break down

http://clang.llvm.org/docs/AutomaticReferenceCounting.html#ownership.spelling.property

assign implies __unsafe_unretained ownership.

copy implies __strong ownership, as well as the usual behavior of copy semantics on the setter.

retain implies __strong ownership.

strong implies __strong ownership.

unsafe_unretained implies __unsafe_unretained ownership.

weak implies __weak ownership.

Color text in discord

Discord doesn't allow colored text. Though, currently, you have two options to "mimic" colored text.

Option #1 (Markdown code-blocks)

Discord supports Markdown and uses highlight.js to highlight code-blocks. Some programming languages have specific color outputs from highlight.js and can be used to mimic colored output.

To use code-blocks, send a normal message in this format (Which follows Markdown's standard format).

```language
message
```

Languages that currently reproduce nice colors: prolog (red/orange), css (yellow).

Option #2 (Embeds)

Discord now supports Embeds and Webhooks, which can be used to display colored blocks, they also support markdown. For documentation on how to use Embeds, please read your lib's documentation.

(Embed Cheat-sheet)
Embed Cheat-sheet

git - Your branch is ahead of 'origin/master' by 1 commit

git reset HEAD <file1> <file2> ...

remove the specified files from the next commit

javascript find and remove object in array based on key value

I agree with the answers, a simple way if you want to find an object by id and remove it is simply like below code.

   var obj = JSON.parse(data);
   var newObj = obj.filter(item=>item.Id!=88);
       

How to stop creating .DS_Store on Mac?

Its is possible by using mach_inject. Take a look at Death to .DS_Store

I found that overriding HFSPlusPropertyStore::FlushChanges() with a function that simply did nothing, successfully prevented the creation of .DS_Store files on both Snow Leopard and Lion.

DeathToDSStore source code

NOTE: On 10.11 you can not inject code into system apps.

Get a timestamp in C in microseconds?

use an unsigned long long (i.e. a 64 bit unit) to represent the system time:

typedef unsigned long long u64;

u64 u64useconds;
struct timeval tv;

gettimeofday(&tv,NULL);
u64useconds = (1000000*tv.tv_sec) + tv.tv_usec;

Using Environment Variables with Vue.js

If you are using Vue cli 3, only variables that start with VUE_APP_ will be loaded.

In the root create a .env file with:

VUE_APP_ENV_VARIABLE=value

And, if it's running, you need to restart serve so that the new env vars can be loaded.

With this, you will be able to use process.env.VUE_APP_ENV_VARIABLE in your project (.js and .vue files).

Update

According to @ali6p, with Vue Cli 3, isn't necessary to install dotenv dependency.

Which is the correct C# infinite loop, for (;;) or while (true)?

In terms of code readability while(true) in whatever language I feel makes more sense. In terms of how the computer sees it there really shouldn't be any difference in today's society of very efficient compilers and interpreters.

If there is any performance difference to be had I'm sure the translation to MSIL will optimise away. You could check that if you really wanted to.

Why am I getting AttributeError: Object has no attribute

These kind of bugs are common when Python multi-threading. What happens is that, on interpreter tear-down, the relevant module (myThread in this case) goes through a sort-of del myThread.

The call self.sample() is roughly equivalent to myThread.__dict__["sample"](self). But if we're during the interpreter's tear-down sequence, then its own dictionary of known types might've already had myThread deleted, and now it's basically a NoneType - and has no 'sample' attribute.

How can I remove an SSH key?

The solution for me (openSUSE Leap 42.3, KDE) was to rename the folder ~/.gnupg which apparently contained the cached keys and profiles.

After KDE logout/logon the ssh-add/agent is running again and the folder is created from scratch, but the old keys are all gone.

I didn't have success with the other approaches.

Convert an image (selected by path) to base64 string

Try this

using (Image image = Image.FromFile(Path))
{
    using (MemoryStream m = new MemoryStream())
    {
        image.Save(m, image.RawFormat);
        byte[] imageBytes = m.ToArray();

        // Convert byte[] to Base64 String
        string base64String = Convert.ToBase64String(imageBytes);
        return base64String;
    }
}

Python - How to concatenate to a string in a for loop?

If you must, this is how you can do it in a for loop:

mylist = ['first', 'second', 'other']
endstring = ''
for s in mylist:
  endstring += s

but you should consider using join():

''.join(mylist)

PHP how to get the base domain/url?

2 lines to solve it

$actual_link = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http") . "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
$myDomain = preg_replace('/^www\./', '', parse_url($actual_link, PHP_URL_HOST));

Difference between save and saveAndFlush in Spring data jpa

On saveAndFlush, changes will be flushed to DB immediately in this command. With save, this is not necessarily true, and might stay just in memory, until flush or commit commands are issued.

But be aware, that even if you flush the changes in transaction and do not commit them, the changes still won't be visible to the outside transactions until the commit in this transaction.

In your case, you probably use some sort of transactions mechanism, which issues commit command for you if everything works out fine.

Reading an image file into bitmap from sdcard, why am I getting a NullPointerException?

Try this code:

Bitmap bitmap = null;
File f = new File(_path);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
try {
    bitmap = BitmapFactory.decodeStream(new FileInputStream(f), null, options);
} catch (FileNotFoundException e) {
    e.printStackTrace();
}         
image.setImageBitmap(bitmap);

Format certain floating dataframe columns into percentage in pandas

Often times we are interested in calculating the full significant digits, but for the visual aesthetics, we may want to see only few decimal point when we display the dataframe.

In jupyter-notebook, pandas can utilize the html formatting taking advantage of the method called style.

For the case of just seeing two significant digits of some columns, we can use this code snippet:

Given dataframe

import numpy as np
import pandas as pd

df = pd.DataFrame({'var1': [1.458315, 1.576704, 1.629253, 1.6693310000000001, 1.705139, 1.740447, 1.77598, 1.812037, 1.85313, 1.9439849999999999],
          'var2': [1.500092, 1.6084450000000001, 1.652577, 1.685456, 1.7120959999999998, 1.741961, 1.7708009999999998, 1.7993270000000001, 1.8229819999999999, 1.8684009999999998],
          'var3': [-0.0057090000000000005, -0.005122, -0.0047539999999999995, -0.003525, -0.003134, -0.0012230000000000001, -0.0017230000000000001, -0.002013, -0.001396, 0.005732]})

print(df)
       var1      var2      var3
0  1.458315  1.500092 -0.005709
1  1.576704  1.608445 -0.005122
2  1.629253  1.652577 -0.004754
3  1.669331  1.685456 -0.003525
4  1.705139  1.712096 -0.003134
5  1.740447  1.741961 -0.001223
6  1.775980  1.770801 -0.001723
7  1.812037  1.799327 -0.002013
8  1.853130  1.822982 -0.001396
9  1.943985  1.868401  0.005732

Style to get required format

    df.style.format({'var1': "{:.2f}",'var2': "{:.2f}",'var3': "{:.2%}"})

Gives:

var1    var2    var3
id          
0   1.46    1.50    -0.57%
1   1.58    1.61    -0.51%
2   1.63    1.65    -0.48%
3   1.67    1.69    -0.35%
4   1.71    1.71    -0.31%
5   1.74    1.74    -0.12%
6   1.78    1.77    -0.17%
7   1.81    1.80    -0.20%
8   1.85    1.82    -0.14%
9   1.94    1.87    0.57%

Update

If display command is not found try following:

from IPython.display import display

df_style = df.style.format({'var1': "{:.2f}",'var2': "{:.2f}",'var3': "{:.2%}"})

display(df_style)

Requirements

  • To use display command, you need to have installed Ipython in your machine.
  • The display command does not work in online python interpreter which do not have IPyton installed such as https://repl.it/languages/python3
  • The display command works in jupyter-notebook, jupyter-lab, Google-colab, kaggle-kernels, IBM-watson,Mode-Analytics and many other platforms out of the box, you do not even have to import display from IPython.display

What does "commercial use" exactly mean?

"Commercial use" in cases like this is actually just a shorthand to indicate that the product is dual-licensed under both an open source and a traditional paid-for commercial license.

Any "true" open source license will not discriminate against commercial use. (See clause 6 of the Open Source Definition.) However, open source licenses like the GPL contain clauses that are incompatible with most companies' approach to commercial software (since the GPL requires that you make your source code available if you incorporate GPL'ed code into your product).

Duel-licensing is a way to accommodate this and also provides a revenue stream for the company providing the software. For users that don't mind the restrictions of the GPL and don't need support, the product is available under an open source license. For users for whom the GPL's restrictions would be incompatible with their business model, and for users that do need support, a commercial license is available.

You gave the specific example of the Screwturn wiki, which is dual-licensed under the GPL and a commercial license. Under the terms of the GPL (i.e., without getting a "commercial" license), you can do the following:

  • Use it internally as much as you want (see here)
  • Run it on your internal servers for external users / clients / customers, or run it on your internal servers for paying clients if you're an ISP / hosting provider. (If Screwturn were licensed under the AGPL instead of the GPL, that might restrict this.)
  • Distribute it to others, either free of charge or for a payment that covers the shipping, as long as you're willing to also distribute the source code
  • Incorporate it into your product, as long as you're willing to also distribute the source code, and as long as either (a) it remains a separate program that you merely aggregate with your product or (b) you release the source code to your product under an open source license compatible with the GPL

In other words, there's a lot that you can do without getting a commercial license. This is especially true for web-based software, since people can use web-based software without it being distributed to them. Screwturn's web site even acknowledges this: they state that the commercial license is for "either integrating it in a commercial application, or using it in an enterprise environment where free software is not allowed," not for any use related to commerce.

All of the preceding is merely my understanding and is not intended to be legal advice. Consult your lawyer to be certain.

Use of min and max functions in C++

fmin and fmax are only for floating point and double variables.

min and max are template functions that allow comparison of any types, given a binary predicate. They can also be used with other algorithms to provide complex functionality.

How to clear an EditText on click?

//To clear When Clear Button is Clicked

firstName = (EditText) findViewById(R.id.firstName);

    clear = (Button) findViewById(R.id.clearsearchSubmit);

    clear.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (v.getId() == R.id.clearsearchSubmit);
            firstName.setText("");
        }
    });

This will help to clear the wrong keywords that you have typed in so instead of pressing backspace again and again you can simply click the button to clear everything.It Worked For me. Hope It Helps

How do I access the $scope variable in browser's console using AngularJS?

This requires jQuery to be installed as well, but works perfectly for a dev environment. It looks through each element to get the instances of the scopes then returns them labelled with there controller names. Its also removing any property start with a $ which is what angularjs generally uses for its configuration.

let controllers = (extensive = false) => {
            let result = {};
            $('*').each((i, e) => {
                let scope = angular.element(e).scope();
                if(Object.prototype.toString.call(scope) === '[object Object]' && e.hasAttribute('ng-controller')) {
                    let slimScope = {};
                    for(let key in scope) {
                        if(key.indexOf('$') !== 0 && key !== 'constructor' || extensive) {
                            slimScope[key] = scope[key];
                        }
                    }
                    result[$(e).attr('ng-controller')] = slimScope;
                }
            });

            return result;
        }

How can I pad an integer with zeros on the left?

Here is another way to pad an integer with zeros on the left. You can increase the number of zeros as per your convenience. Have added a check to return the same value as is in case of negative number or a value greater than or equals to zeros configured. You can further modify as per your requirement.

/**
 * 
 * @author Dinesh.Lomte
 *
 */
public class AddLeadingZerosToNum {
    
    /**
     * 
     * @param args
     */
    public static void main(String[] args) {
        
        System.out.println(getLeadingZerosToNum(0));
        System.out.println(getLeadingZerosToNum(7));
        System.out.println(getLeadingZerosToNum(13));
        System.out.println(getLeadingZerosToNum(713));
        System.out.println(getLeadingZerosToNum(7013));
        System.out.println(getLeadingZerosToNum(9999));
    }
    /**
     * 
     * @param num
     * @return
     */
    private static String getLeadingZerosToNum(int num) {
        // Initializing the string of zeros with required size
        String zeros = new String("0000");
        // Validating if num value is less then zero or if the length of number 
        // is greater then zeros configured to return the num value as is
        if (num < 0 || String.valueOf(num).length() >= zeros.length()) {
            return String.valueOf(num);
        }
        // Returning zeros in case if value is zero.
        if (num == 0) {
            return zeros;
        }
        return new StringBuilder(zeros.substring(0, zeros.length() - 
                String.valueOf(num).length())).append(
                        String.valueOf(num)).toString();
    }
}

Input

0

7

13

713

7013

9999

Output

0000

0007

0013

7013

9999

Marker in leaflet, click event

Additional relevant info: A common need is to pass the ID of the object represented by the marker to some ajax call for the purpose of fetching more info from the server.

It seems that when we do:

marker.on('click', function(e) {...

The e points to a MouseEvent, which does not let us get to the marker object. But there is a built-in this object which strangely, requires us to use this.options to get to the options object which let us pass anything we need. In the above case, we can pass some ID in an option, let's say objid then within the function above, we can get the value by invoking: this.options.objid

converting epoch time with milliseconds to datetime

those are miliseconds, just divide them by 1000, since gmtime expects seconds ...

time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(1236472051807/1000.0))

What does <T> denote in C#

It is a generic type parameter, see Generics documentation.

T is not a reserved keyword. T, or any given name, means a type parameter. Check the following method (just as a simple example).

T GetDefault<T>()
{
    return default(T);
}

Note that the return type is T. With this method you can get the default value of any type by calling the method as:

GetDefault<int>(); // 0
GetDefault<string>(); // null
GetDefault<DateTime>(); // 01/01/0001 00:00:00
GetDefault<TimeSpan>(); // 00:00:00

.NET uses generics in collections, ... example:

List<int> integerList = new List<int>();

This way you will have a list that only accepts integers, because the class is instancited with the type T, in this case int, and the method that add elements is written as:

public class List<T> : ...
{
    public void Add(T item);
}

Some more information about generics.

You can limit the scope of the type T.

The following example only allows you to invoke the method with types that are classes:

void Foo<T>(T item) where T: class
{
}

The following example only allows you to invoke the method with types that are Circle or inherit from it.

void Foo<T>(T item) where T: Circle
{
}

And there is new() that says you can create an instance of T if it has a parameterless constructor. In the following example T will be treated as Circle, you get intellisense...

void Foo<T>(T item) where T: Circle, new()
{
    T newCircle = new T();
}

As T is a type parameter, you can get the object Type from it. With the Type you can use reflection...

void Foo<T>(T item) where T: class
{
    Type type = typeof(T);
}

As a more complex example, check the signature of ToDictionary or any other Linq method.

public static Dictionary<TKey, TSource> ToDictionary<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector);

There isn't a T, however there is TKey and TSource. It is recommended that you always name type parameters with the prefix T as shown above.

You could name TSomethingFoo if you want to.

How to create nested directories using Mkdir in Golang?

If the issue is to create all the necessary parent directories, you could consider using os.MkDirAll()

MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error.

The path_test.go is a good illustration on how to use it:

func TestMkdirAll(t *testing.T) {
    tmpDir := TempDir()
    path := tmpDir + "/_TestMkdirAll_/dir/./dir2"
    err := MkdirAll(path, 0777)
    if err != nil {
    t.Fatalf("MkdirAll %q: %s", path, err)
    }
    defer RemoveAll(tmpDir + "/_TestMkdirAll_")
...
}

(Make sure to specify a sensible permission value, as mentioned in this answer)

Core dump file is not generated

Make sure your current directory (at the time of crash -- server may change directories) is writable. If the server calls setuid, the directory has to be writable by that user.

Also check /proc/sys/kernel/core_pattern. That may redirect core dumps to another directory, and that directory must be writable. More info here.

Hiding a sheet in Excel 2007 (with a password) OR hide VBA code in Excel

Here is what you do in Excel 2003:

  1. In your sheet of interest, go to Format -> Sheet -> Hide and hide your sheet.
  2. Go to Tools -> Protection -> Protect Workbook, make sure Structure is selected, and enter your password of choice.

Here is what you do in Excel 2007:

  1. In your sheet of interest, go to Home ribbon -> Format -> Hide & Unhide -> Hide Sheet and hide your sheet.
  2. Go to Review ribbon -> Protect Workbook, make sure Structure is selected, and enter your password of choice.

Once this is done, the sheet is hidden and cannot be unhidden without the password. Make sense?


If you really need to keep some calculations secret, try this: use Access (or another Excel workbook or some other DB of your choice) to calculate what you need calculated, and export only the "unclassified" results to your Excel workbook.

Python string.join(list) on object array rather than string array

The built-in string constructor will automatically call obj.__str__:

''.join(map(str,list))

MySQL Insert query doesn't work with WHERE clause

A way to use INSERT and WHERE is

INSERT INTO MYTABLE SELECT 953,'Hello',43 WHERE 0 in (SELECT count(*) FROM MYTABLE WHERE myID=953); In this case ist like an exist-test. There is no exception if you run it two or more times...

Is there a cross-browser onload event when clicking the back button?

Guys, I found that JQuery has only one effect: the page is reloaded when the back button is pressed. This has nothing to do with "ready".

How does this work? Well, JQuery adds an onunload event listener.

// http://code.jquery.com/jquery-latest.js
jQuery(window).bind("unload", function() { // ...

By default, it does nothing. But somehow this seems to trigger a reload in Safari, Opera and Mozilla -- no matter what the event handler contains.

[edit(Nickolay): here's why it works that way: webkit.org, developer.mozilla.org. Please read those articles (or my summary in a separate answer below) and consider whether you really need to do this and make your page load slower for your users.]

Can't believe it? Try this:

<body onunload=""><!-- This does the trick -->
<script type="text/javascript">
    alert('first load / reload');
    window.onload = function(){alert('onload')};
</script>
<a href="http://stackoverflow.com">click me, then press the back button</a>
</body>

You will see similar results when using JQuery.

You may want to compare to this one without onunload

<body><!-- Will not reload on back button -->
<script type="text/javascript">
    alert('first load / reload');
    window.onload = function(){alert('onload')};
</script>
<a href="http://stackoverflow.com">click me, then press the back button</a>
</body>

Get bottom and right position of an element

Here is a jquery function that returns an object of any class or id on the page

var elementPosition = function(idClass) {
            var element = $(idClass);
            var offset = element.offset();

            return {
                'top': offset.top,
                'right': offset.left + element.outerWidth(),
                'bottom': offset.top + element.outerHeight(),
                'left': offset.left,
            };
        };


        console.log(elementPosition('#my-class-or-id'));

How to set variable from a SQL query?

You can use this, but remember that your query gives 1 result, multiple results will throw the exception.

declare @ModelID uniqueidentifer
Set @ModelID = (select Top(1) modelid from models where areaid = 'South Coast')

Another way:

Select Top(1)@ModelID = modelid from models where areaid = 'South Coast'

Why can't I display a pound (£) symbol in HTML?

You need to save your PHP script file in UTF-8 encoding, and leave the <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> in the HTML.

For text editor, I recommend Notepad++, because it can detect and display the actual encoding of the file (in the lower right corner of the editor), and you can convert it as well.

Remove NaN from pandas series

If you have a pandas serie with NaN, and want to remove it (without loosing index):

serie = serie.dropna()

# create data for example
data = np.array(['g', 'e', 'e', 'k', 's']) 
ser = pd.Series(data)
ser.replace('e', np.NAN)
print(ser)

0      g
1    NaN
2    NaN
3      k
4      s
dtype: object

# the code
ser = ser.dropna()
print(ser)

0    g
3    k
4    s
dtype: object

How to fix curl: (60) SSL certificate: Invalid certificate chain

After attempting all of the above solutions to eliminate the "curl: (60) SSL certificate problem: unable to get local issuer certificate" error, the solution that finally worked for me on OSX 10.9 was:

  1. Locate the curl certificate PEM file location 'curl-config --ca' -- > /usr/local/etc/openssl/cert.pem

  2. Use the folder location to identify the PEM file 'cd /usr/local/etc/openssl'

  3. Create a backup of the cert.pem file 'cp cert.pem cert_pem.bkup'

  4. Download the updated Certificate file from the curl website 'sudo wget http://curl.haxx.se/ca/cacert.pem'

  5. Copy the downloaded PEM file to replace the old PEM file 'cp cacert.pem cert.pem'

    This is a modified version of a solution posted to correct the same issue in Ubuntu found here:

https://serverfault.com/questions/151157/ubuntu-10-04-curl-how-do-i-fix-update-the-ca-bundle

Error Message: Type or namespace definition, or end-of-file expected

  1. Make sure you have System.Web referenced
  2. Get rid of the two } at the end.

Server returned HTTP response code: 401 for URL: https

Try This. You need pass the authentication to let the server know its a valid user. You need to import these two packages and has to include a jersy jar. If you dont want to include jersy jar then import this package

import sun.misc.BASE64Encoder;

import com.sun.jersey.core.util.Base64;
import sun.net.www.protocol.http.HttpURLConnection;

and then,

String encodedAuthorizedUser = getAuthantication("username", "password");
URL url = new URL("Your Valid Jira URL");
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setRequestProperty ("Authorization", "Basic " + encodedAuthorizedUser );

 public String getAuthantication(String username, String password) {
   String auth = new String(Base64.encode(username + ":" + password));
   return auth;
 }

How to remove/ignore :hover css style on touch devices

It was helpful for me: link

function hoverTouchUnstick() {
    // Check if the device supports touch events
    if('ontouchstart' in document.documentElement) {
        // Loop through each stylesheet
        for(var sheetI = document.styleSheets.length - 1; sheetI >= 0; sheetI--) {
            var sheet = document.styleSheets[sheetI];
            // Verify if cssRules exists in sheet
            if(sheet.cssRules) {
                // Loop through each rule in sheet
                for(var ruleI = sheet.cssRules.length - 1; ruleI >= 0; ruleI--) {
                    var rule = sheet.cssRules[ruleI];
                    // Verify rule has selector text
                    if(rule.selectorText) {
                        // Replace hover psuedo-class with active psuedo-class
                        rule.selectorText = rule.selectorText.replace(":hover", ":active");
                    }
                }
            }
        }
    }
}

Turn off enclosing <p> tags in CKEditor 3.0

I'm doing something I'm not proud of as workaround. In my Python servlet that actually saves to the database, I do:

if description.startswith('<p>') and description.endswith('</p>'):
    description = description[3:-4]