Programs & Examples On #Validation application bl

The Enterprise Library Validation Application Block provides a library of classes, called validators, that supplies the code for validating .NET Framework data types. For example, one validator checks for null strings and another validator checks that a number falls within a specified range.

Understanding ibeacon distancing

I'm very thoroughly investigating the matter of accuracy/rssi/proximity with iBeacons and I really really think that all the resources in the Internet (blogs, posts in StackOverflow) get it wrong.

davidgyoung (accepted answer, > 100 upvotes) says:

Note that the term "accuracy" here is iOS speak for distance in meters.

Actually, most people say this but I have no idea why! Documentation makes it very very clear that CLBeacon.proximity:

Indicates the one sigma horizontal accuracy in meters. Use this property to differentiate between beacons with the same proximity value. Do not use it to identify a precise location for the beacon. Accuracy values may fluctuate due to RF interference.

Let me repeat: one sigma accuracy in meters. All 10 top pages in google on the subject has term "one sigma" only in quotation from docs, but none of them analyses the term, which is core to understand this.

Very important is to explain what is actually one sigma accuracy. Following URLs to start with: http://en.wikipedia.org/wiki/Standard_error, http://en.wikipedia.org/wiki/Uncertainty

In physical world, when you make some measurement, you always get different results (because of noise, distortion, etc) and very often results form Gaussian distribution. There are two main parameters describing Gaussian curve:

  1. mean (which is easy to understand, it's value for which peak of the curve occurs).
  2. standard deviation, which says how wide or narrow the curve is. The narrower curve, the better accuracy, because all results are close to each other. If curve is wide and not steep, then it means that measurements of the same phenomenon differ very much from each other, so measurement has a bad quality.

one sigma is another way to describe how narrow/wide is gaussian curve.
It simply says that if mean of measurement is X, and one sigma is s, then 68% of all measurements will be between X - s and X + s.

Example. We measure distance and get a gaussian distribution as a result. The mean is 10m. If s is 4m, then it means that 68% of measurements were between 6m and 14m.

When we measure distance with beacons, we get RSSI and 1-meter calibration value, which allow us to measure distance in meters. But every measurement gives different values, which form gaussian curve. And one sigma (and accuracy) is accuracy of the measurement, not distance!

It may be misleading, because when we move beacon further away, one sigma actually increases because signal is worse. But with different beacon power-levels we can get totally different accuracy values without actually changing distance. The higher power, the less error.

There is a blog post which thoroughly analyses the matter: http://blog.shinetech.com/2014/02/17/the-beacon-experiments-low-energy-bluetooth-devices-in-action/

Author has a hypothesis that accuracy is actually distance. He claims that beacons from Kontakt.io are faulty beacuse when he increased power to the max value, accuracy value was very small for 1, 5 and even 15 meters. Before increasing power, accuracy was quite close to the distance values. I personally think that it's correct, because the higher power level, the less impact of interference. And it's strange why Estimote beacons don't behave this way.

I'm not saying I'm 100% right, but apart from being iOS developer I have degree in wireless electronics and I think that we shouldn't ignore "one sigma" term from docs and I would like to start discussion about it.

It may be possible that Apple's algorithm for accuracy just collects recent measurements and analyses the gaussian distribution of them. And that's how it sets accuracy. I wouldn't exclude possibility that they use info form accelerometer to detect whether user is moving (and how fast) in order to reset the previous distribution distance values because they have certainly changed.

Installing packages in Sublime Text 2

With Package Control in Sublime Text 2, you really need to become cozy with a couple of different things to make it all work:

  1. Always look up a package in the wbond community. There you'll be able to see how many people have installed that package (the more popular, the better) as well as the documentation on the package (if any).
  2. Menu Items under Prefs > Package Control. Here you can install, remove or see a list of all installed packages.
  3. Prefs > Package Settings. Here you'll find the settings that can be tinkered with as well as shortcut keys that are available. Make sure to make any changes in the User Settings, rather than the Default Settings. Otherwise, your settings will be overwritten when that package is updated.
  4. CTRL+SHIFT+P. This will bring up a menu where you can look up a lot of the functions your installed packages can do. Just start typing and it will start filtering.

Execute a stored procedure in another stored procedure in SQL server

Your sp_test: Return fullname

USE [MY_DB]
GO

IF (OBJECT_ID('[dbo].[sp_test]', 'P') IS NOT NULL)
DROP PROCEDURE [dbo].sp_test;
GO

CREATE PROCEDURE [dbo].sp_test 
@name VARCHAR(20),
@last_name VARCHAR(30),
@full_name VARCHAR(50) OUTPUT
AS

SET @full_name = @name + @last_name;

GO

In your sp_main

...
DECLARE @my_name VARCHAR(20);
DECLARE @my_last_name VARCHAR(30);
DECLARE @my_full_name VARCHAR(50);
...

EXEC sp_test @my_name, @my_last_name, @my_full_name OUTPUT;
...

OnClickListener in Android Studio

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

    setContentView(R.layout.activity_my);
    titolorecuperato = (TextView) findViewById(R.id.textView);
    String stitolo = titolorecuperato.getText().toString();

    Button btnHome = (Button) findViewById(R.id.button);

    btnHome.setOnClickListener(new View.OnClickListener() {

       @Override
        public void onClick(View view) {

       }
});

same thing as Nic007 said before.

You do need to write code inside "onCreate" method. Sorry me too for the indent... (first comment here)

How can I align the columns of tables in Bash?

printf is great, but people forget about it.

$ for num in 1 10 100 1000 10000 100000 1000000; do printf "%10s %s\n" $num "foobar"; done
         1 foobar
        10 foobar
       100 foobar
      1000 foobar
     10000 foobar
    100000 foobar
   1000000 foobar

$ for((i=0;i<array_size;i++));
do
    printf "%10s %10d %10s" stringarray[$i] numberarray[$i] anotherfieldarray[%i]
done

Notice I used %10s for strings. %s is the important part. It tells it to use a string. The 10 in the middle says how many columns it is to be. %d is for numerics (digits).

man 1 printf for more info.

Button Center CSS

I realize this is a very old question, but I stumbled across this problem today and I got it to work with

<div style="text-align:center;">
    <button>button1</button>
    <button>button2</button>
</div>

Cheers, Mark

How do I kill an Activity when the Back button is pressed?

public boolean onKeyDown(int keycode, KeyEvent event) {
    if (keycode == KeyEvent.KEYCODE_BACK) {
        moveTaskToBack(true);
    }
    return super.onKeyDown(keycode, event);
}

My app closed with above code.

How to access JSON Object name/value?

Here is a friendly piece of advice. Use something like Chrome Developer Tools or Firebug for Firefox to inspect your Ajax calls and results.

You may also want to invest some time in understanding a helper library like Underscore, which complements jQuery and gives you 60+ useful functions for manipulating data objects with JavaScript.

How to detect when an Android app goes to the background and come back to the foreground

You can use the ProcessLifecycleOwner attaching a lifecycle observer to it.

  public class ForegroundLifecycleObserver implements LifecycleObserver {

    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    public void onAppCreated() {
        Timber.d("onAppCreated() called");
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    public void onAppStarted() {
        Timber.d("onAppStarted() called");
    }

    @OnLifecycleEvent(Event.ON_RESUME)
    public void onAppResumed() {
        Timber.d("onAppResumed() called");
    }

    @OnLifecycleEvent(Event.ON_PAUSE)
    public void onAppPaused() {
        Timber.d("onAppPaused() called");
    }

    @OnLifecycleEvent(Event.ON_STOP)
    public void onAppStopped() {
        Timber.d("onAppStopped() called");
    }
}

then on the onCreate() of your Application class you call this:

ProcessLifecycleOwner.get().getLifecycle().addObserver(new ForegroundLifecycleObserver());

with this you will be able to capture the events of ON_PAUSE and ON_STOP of your application that happen when it goes in background.

Best way to represent a Grid or Table in AngularJS with Bootstrap 3?

With "thousands of rows" your best bet would obviously be to do server side paging. When I looked into the different AngularJs table/grid options a while back there were three clear favourites:

All three are good, but implemented differently. Which one you pick will probably be more based on personal preference than anything else.

ng-grid is probably the most known due to its association with angular-ui, but I personally prefer ng-table, I really like their implementation and how you use it, and they have great documentation and examples available and actively being improved.

How to use the DropDownList's SelectedIndexChanged event

The most basic way you can do this in SelectedIndexChanged events of DropDownLists. Check this code..

    <asp:DropDownList ID="DropDownList1" runat="server" onselectedindexchanged="DropDownList1_SelectedIndexChanged" Width="224px"
        AutoPostBack="True" AppendDataBoundItems="true">
    <asp:DropDownList ID="DropDownList2" runat="server"
        onselectedindexchanged="DropDownList2_SelectedIndexChanged">
    </asp:DropDownList> 


protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    //Load DropDownList2

}
protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
{
    //Load DropDownList3
}

Taking screenshot on Emulator from Android Studio

Android Device Monitor was deprecated in Android Studio 3.1 and removed from Android Studio 3.2. To start the standalone Device Monitor application in Android Studio 3.1 and lower you can run android-sdk/tools/monitor.bat

Java, Shifting Elements in an Array

Instead of shifting by one position you can make this function more general using module like this.

int[] original = { 1, 2, 3, 4, 5, 6 };
int[] reordered = new int[original.length];
int shift = 1;

for(int i=0; i<original.length;i++)
     reordered[i] = original[(shift+i)%original.length];

How to call a stored procedure from Java and JPA

From JPA 2.1 , JPA supports to call stored procedures using the dynamic StoredProcedureQuery, and the declarative @NamedStoredProcedureQuery.

Best way to do a split pane in HTML

Improving on Reza's answer:

  • prevent the browser from interfering with a drag
  • prevent setting an element to a negative size
  • prevent drag getting out of sync with the mouse due to incremental delta interaction with element width saturation

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<html><head><style>

.splitter {
    width: 100%;
    height: 100px;
    display: flex;
}

#separator {
    cursor: col-resize;
    background-color: #aaa;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='30'><path d='M2 0 v30 M5 0 v30 M8 0 v30' fill='none' stroke='black'/></svg>");
    background-repeat: no-repeat;
    background-position: center;
    width: 10px;
    height: 100%;

    /* Prevent the browser's built-in drag from interfering */
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

#first {
    background-color: #dde;
    width: 20%;
    height: 100%;
    min-width: 10px;
}

#second {
    background-color: #eee;
    width: 80%;
    height: 100%;
    min-width: 10px;
}

</style></head><body>

<div class="splitter">
    <div id="first"></div>
    <div id="separator" ></div>
    <div id="second" ></div>
</div>

<script>

// A function is used for dragging and moving
function dragElement(element, direction)
{
    var   md; // remember mouse down info
    const first  = document.getElementById("first");
    const second = document.getElementById("second");

    element.onmousedown = onMouseDown;

    function onMouseDown(e)
    {
        //console.log("mouse down: " + e.clientX);
        md = {e,
              offsetLeft:  element.offsetLeft,
              offsetTop:   element.offsetTop,
              firstWidth:  first.offsetWidth,
              secondWidth: second.offsetWidth
             };

        document.onmousemove = onMouseMove;
        document.onmouseup = () => {
            //console.log("mouse up");
            document.onmousemove = document.onmouseup = null;
        }
    }

    function onMouseMove(e)
    {
        //console.log("mouse move: " + e.clientX);
        var delta = {x: e.clientX - md.e.clientX,
                     y: e.clientY - md.e.clientY};

        if (direction === "H" ) // Horizontal
        {
            // Prevent negative-sized elements
            delta.x = Math.min(Math.max(delta.x, -md.firstWidth),
                       md.secondWidth);

            element.style.left = md.offsetLeft + delta.x + "px";
            first.style.width = (md.firstWidth + delta.x) + "px";
            second.style.width = (md.secondWidth - delta.x) + "px";
        }
    }
}


dragElement( document.getElementById("separator"), "H" );

</script></body></html>
_x000D_
_x000D_
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How do I rename all folders and files to lowercase on Linux?

I needed to do this on a Cygwin setup on Windows 7 and found that I got syntax errors with the suggestions from above that I tried (though I may have missed a working option). However, this solution straight from Ubuntu forums worked out of the can :-)

ls | while read upName; do loName=`echo "${upName}" | tr '[:upper:]' '[:lower:]'`; mv "$upName" "$loName"; done

(NB: I had previously replaced whitespace with underscores using:

for f in *\ *; do mv "$f" "${f// /_}"; done

)

How to get a list of column names on Sqlite3 database?

Just for super noobs like me wondering how or what people meant by

PRAGMA table_info('table_name') 

You want to use use that as your prepare statement as shown below. Doing so selects a table that looks like this except is populated with values pertaining to your table.

cid         name        type        notnull     dflt_value  pk        
----------  ----------  ----------  ----------  ----------  ----------
0           id          integer     99                      1         
1           name                    0                       0

Where id and name are the actual names of your columns. So to get that value you need to select column name by using:

//returns the name
sqlite3_column_text(stmt, 1);
//returns the type
sqlite3_column_text(stmt, 2);

Which will return the current row's column's name. To grab them all or find the one you want you need to iterate through all the rows. Simplest way to do so would be in the manner below.

//where rc is an int variable if wondering :/
rc = sqlite3_prepare_v2(dbPointer, "pragma table_info ('your table name goes here')", -1, &stmt, NULL);

if (rc==SQLITE_OK)
{
    //will continue to go down the rows (columns in your table) till there are no more
    while(sqlite3_step(stmt) == SQLITE_ROW)
    {
        sprintf(colName, "%s", sqlite3_column_text(stmt, 1));
        //do something with colName because it contains the column's name
    }
}

Oracle SQL Developer: Failure - Test failed: The Network Adapter could not establish the connection?

I solved just by: given correct host and port so:

  1. Open oracle net manager
  2. Local
  3. Listener

in Listener on address 2 then copy host to Oracle Developer

finally connect to oracle

Python equivalent for HashMap

You need a dict:

my_dict = {'cheese': 'cake'}

Example code (from the docs):

>>> a = dict(one=1, two=2, three=3)
>>> b = {'one': 1, 'two': 2, 'three': 3}
>>> c = dict(zip(['one', 'two', 'three'], [1, 2, 3]))
>>> d = dict([('two', 2), ('one', 1), ('three', 3)])
>>> e = dict({'three': 3, 'one': 1, 'two': 2})
>>> a == b == c == d == e
True

You can read more about dictionaries here.

Reference to a non-shared member requires an object reference occurs when calling public sub

You either have to make the method Shared or use an instance of the class General:

Dim gen = New General()
gen.updateDynamics(get_prospect.dynamicsID)

or

General.updateDynamics(get_prospect.dynamicsID)

Public Shared Sub updateDynamics(dynID As Int32)
    ' ... '
End Sub

Shared(VB.NET)

Fixing broken UTF-8 encoding

As Dan pointed out: you need to convert them to binary and then convert/correct the encoding.

E.g., for utf8 stored as latin1 the following SQL will fix it:

UPDATE table
   SET field = CONVERT( CAST(field AS BINARY) USING utf8)
 WHERE $broken_field_condition

How to re-enable right click so that I can inspect HTML elements in Chrome?

Open inspect mode before navigating to the page. It worked.hehe

C++ compile time error: expected identifier before numeric constant

Since your compiler probably doesn't support all of C++11 yet, which supports similar syntax, you're getting these errors because you have to initialize your class members in constructors:

Attribute() : name(5),val(5,0) {}

MVC Return Partial View as JSON

You can extract the html string from the PartialViewResult object, similar to the answer to this thread:

Render a view as a string

PartialViewResult and ViewResult both derive from ViewResultBase, so the same method should work on both.

Using the code from the thread above, you would be able to use:

public ActionResult ReturnSpecialJsonIfInvalid(AwesomenessModel model)
{
    if (ModelState.IsValid)
    {
        if(Request.IsAjaxRequest())
            return PartialView("NotEvil", model);
        return View(model)
    }
    if(Request.IsAjaxRequest())
    {
        return Json(new { error = true, message = RenderViewToString(PartialView("Evil", model))});
    }
    return View(model);
}

yii2 redirect in controller action does not work?

Redirects the browser to the specified URL.

This method adds a "Location" header to the current response. Note that it does not send out the header until send() is called. In a controller action you may use this method as follows:

return Yii::$app->getResponse()->redirect($url);

In other places, if you want to send out the "Location" header immediately, you should use the following code:

Yii::$app->getResponse()->redirect($url)->send();
return;

Git diff between current branch and master but not including unmerged master commits

git diff `git merge-base master branch`..branch

Merge base is the point where branch diverged from master.

Git diff supports a special syntax for this:

git diff master...branch

You must not swap the sides because then you would get the other branch. You want to know what changed in branch since it diverged from master, not the other way round.

Loosely related:


Note that .. and ... syntax does not have the same semantics as in other Git tools. It differs from the meaning specified in man gitrevisions.

Quoting man git-diff:

  • git diff [--options] <commit> <commit> [--] [<path>…]

    This is to view the changes between two arbitrary <commit>.

  • git diff [--options] <commit>..<commit> [--] [<path>…]

    This is synonymous to the previous form. If <commit> on one side is omitted, it will have the same effect as using HEAD instead.

  • git diff [--options] <commit>...<commit> [--] [<path>…]

    This form is to view the changes on the branch containing and up to the second <commit>, starting at a common ancestor of both <commit>. "git diff A...B" is equivalent to "git diff $(git-merge-base A B) B". You can omit any one of <commit>, which has the same effect as using HEAD instead.

Just in case you are doing something exotic, it should be noted that all of the <commit> in the above description, except in the last two forms that use ".." notations, can be any <tree>.

For a more complete list of ways to spell <commit>, see "SPECIFYING REVISIONS" section in gitrevisions[7]. However, "diff" is about comparing two endpoints, not ranges, and the range notations ("<commit>..<commit>" and "<commit>...<commit>") do not mean a range as defined in the "SPECIFYING RANGES" section in gitrevisions[7].

FlutterError: Unable to load asset

While I was loading a new image in my asset folder, I just encountered the problem every time.

I run flutter clean & then restarted the Android Studio. Seems like flutter packages caches the asset folder and there is no mechanism to update the cache when a developer adds a new image in the project (Personal thoughts).

What are the default access modifiers in C#?

Namespace level: internal

Type level: private

jQuery: print_r() display equivalent?

You could use very easily reflection to list all properties, methods and values.

For Gecko based browsers you can use the .toSource() method:

var data = new Object();
data["firstname"] = "John";
data["lastname"] = "Smith";
data["age"] = 21;

alert(data.toSource()); //Will return "({firstname:"John", lastname:"Smith", age:21})"

But since you use Firebug, why not just use console.log?

git: fatal: I don't handle protocol '??http'

I used double quotes for the URL and it worked. So something like

git clone "??http://git.fedorahosted.org/git/ibus-typing-booster.git"

works.. single quotes dont help. It has to be double quotes.

ASP.NET Core - Swashbuckle not creating swagger.json file

Adding a relative path worked for me:

app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("../swagger/v1/swagger.json", "My App");
});

How to check if an element of a list is a list (in Python)?

  1. Work out what specific properties of a list you want the items to have. Do they need to be indexable? Sliceable? Do they need an .append() method?

  2. Look up the abstract base class which describes that particular type in the collections module.

  3. Use isinstance:

    isinstance(x, collections.MutableSequence)
    

You might ask "why not just use type(x) == list?" You shouldn't do that, because then you won't support things that look like lists. And part of the Python mentality is duck typing:

I see a bird that walks like a duck and swims like a duck and quacks like a duck, I call that bird a duck

In other words, you shouldn't require that the objects are lists, just that they have the methods you will need. The collections module provides a bunch of abstract base classes, which are a bit like Java interfaces. Any type that is an instance of collections.Sequence, for example, will support indexing.

How to set a Header field on POST a form?

From FormData documention:

XMLHttpRequest Level 2 adds support for the new FormData interface. FormData objects provide a way to easily construct a set of key/value pairs representing form fields and their values, which can then be easily sent using the XMLHttpRequest send() method.

With an XMLHttpRequest you can set the custom headers and then do the POST.

Why use Gradle instead of Ant or Maven?

It's also much easier to manage native builds. Ant and Maven are effectively Java-only. Some plugins exist for Maven that try to handle some native projects, but they don't do an effective job. Ant tasks can be written that compile native projects, but they are too complex and awkward.

We do Java with JNI and lots of other native bits. Gradle simplified our Ant mess considerably. When we started to introduce dependency management to the native projects it was messy. We got Maven to do it, but the equivalent Gradle code was a tiny fraction of what was needed in Maven, and people could read it and understand it without becoming Maven gurus.

Android ClassNotFoundException: Didn't find class on path

I faced this error once when I defined a class that extended a view but referred to this custom view in the layout file with the wrong name. Instead of <com.example.customview/>, I had included <com.customview/> in the XML layout file.

Git push existing repo to a new and different remote repo server?

There is a deleted answer on this question that had a useful link: https://help.github.com/articles/duplicating-a-repository

The gist is

0. create the new empty repository (say, on github)
1. make a bare clone of the repository in some temporary location
2. change to the temporary location
3. perform a mirror-push to the new repository
4. change to another location and delete the temporary location

OP's example:

On your local machine

$ cd $HOME
$ git clone --bare https://git.fedorahosted.org/the/path/to/my_repo.git
$ cd my_repo.git
$ git push --mirror https://github.com/my_username/my_repo.git
$ cd ..
$ rm -rf my_repo.git

How do I check in python if an element of a list is empty?

Just check if that element is equal to None type or make use of NOT operator ,which is equivalent to the NULL type you observe in other languages.

if not A[i]:
    ## do whatever

Anyway if you know the size of your list then you don't need to do all this.

How to install a Python module via its setup.py in Windows?

setup.py is designed to be run from the command line. You'll need to open your command prompt (In Windows 7, hold down shift while right-clicking in the directory with the setup.py file. You should be able to select "Open Command Window Here").

From the command line, you can type

python setup.py --help

...to get a list of commands. What you are looking to do is...

python setup.py install

PHP Fatal error: Class 'PDO' not found

This can also happen if there is a php.ini file in the web app's current working directory. If one has been placed there to change certain settings, it will override the global one.

To avoid this problem, don't use a php.ini file to change settings; instead you can:

  • Specify settings in the vhost declaration
  • Use an .htaccess file with php_flag (see here)
  • Use an .user.ini file (see here)

How to allow user to pick the image with Swift?

For Swift 4
This code working for me!!

import UIKit


class ViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {

    @IBOutlet var imageView: UIImageView!
    @IBOutlet var chooseBuuton: UIButton!
    var imagePicker = UIImagePickerController()

    override func viewDidLoad() {
        super.viewDidLoad()
        imagePicker.delegate = self
    }
    @IBAction func btnClicked() {

    if UIImagePickerController.isSourceTypeAvailable(.savedPhotosAlbum) 
    {
        print("Button capture")
        imagePicker.sourceType = .savedPhotosAlbum;
        imagePicker.allowsEditing = false

        self.present(imagePicker, animated: true, completion: nil)
        }
    }

  @objc func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    let chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage
    imageView.image = chosenImage

    dismiss(animated: true, completion: nil)
    }
}

Bootstrap 3 modal vertical position center

The simplest solution is to add modal dialog styles to the top of the page or import css with this code:

<style>
    .modal-dialog {
    position:absolute;
    top:50% !important;
    transform: translate(0, -50%) !important;
    -ms-transform: translate(0, -50%) !important;
    -webkit-transform: translate(0, -50%) !important;
    margin:auto 50%;
    width:40%;
    height:40%;
    }
</style>

Modal declaration:

    <div class="modal fade" id="exampleModalCenter" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5>
                <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                    <span aria-hidden="true">&times;</span>
                </button>
            </div>
            <div class="modal-body">
                ...
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
                <button type="button" class="btn btn-primary">Save changes</button>
            </div>
        </div>
    </div>
</div>

Modal usage:

<a data-toggle="modal" data-target="#exampleModalCenter">
 ...
</a>

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.

jQuery get value of select onChange

Let me share an example which I developed with BS4, thymeleaf and Spring boot.

I am using two SELECTs, where the second ("subtopic") gets filled by an AJAX call based on the selection of the first("topic").

First, the thymeleaf snippet:

 <div class="form-group">
     <label th:for="topicId" th:text="#{label.topic}">Topic</label>
     <select class="custom-select"
             th:id="topicId" th:name="topicId"
             th:field="*{topicId}"
             th:errorclass="is-invalid" required>
         <option value="" selected
                 th:text="#{option.select}">Select
         </option>
         <optgroup th:each="topicGroup : ${topicGroups}"
                   th:label="${topicGroup}">
             <option th:each="topicItem : ${topics}"
                     th:if="${topicGroup == topicItem.grp} "
                     th:value="${{topicItem.baseIdentity.id}}"
                     th:text="${topicItem.name}"
                     th:selected="${{topicItem.baseIdentity.id==topicId}}">
             </option>
         </optgroup>
         <option th:each="topicIter : ${topics}"
                 th:if="${topicIter.grp == ''} "
                 th:value="${{topicIter.baseIdentity.id}}"
                 th:text="${topicIter.name}"
                 th:selected="${{topicIter.baseIdentity?.id==topicId}}">
         </option>
     </select>
     <small id="topicHelp" class="form-text text-muted"
            th:text="#{label.topic.tt}">select</small>
</div><!-- .form-group -->

<div class="form-group">
    <label for="subtopicsId" th:text="#{label.subtopicsId}">subtopics</label>
    <select class="custom-select"
            id="subtopicsId" name="subtopicsId"
            th:field="*{subtopicsId}"
            th:errorclass="is-invalid" multiple="multiple">
        <option value="" disabled
                th:text="#{option.multiple.optional}">Select
        </option>
        <option th:each="subtopicsIter : ${subtopicsList}"
                th:value="${{subtopicsIter.baseIdentity.id}}"
                th:text="${subtopicsIter.name}">
        </option>
    </select>
    <small id="subtopicsHelp" class="form-text text-muted"
           th:unless="${#fields.hasErrors('subtopicsId')}"
           th:text="#{label.subtopics.tt}">select</small>
    <small id="subtopicsIdError" class="invalid-feedback"
           th:if="${#fields.hasErrors('subtopicsId')}"
           th:errors="*{subtopicsId}">Errors</small>
</div><!-- .form-group -->

I am iterating over a list of topics that is stored in the model context, showing all groups with their topics, and after that all topics that do not have a group. BaseIdentity is an @Embedded composite key BTW.

Now, here's the jQuery that handles changes:

$('#topicId').change(function () {
    selectedOption = $(this).val();
    if (selectedOption === "") {
        $('#subtopicsId').prop('disabled', 'disabled').val('');
        $("#subtopicsId option").slice(1).remove(); // keep first
    } else {
        $('#subtopicsId').prop('disabled', false)
        var orig = $(location).attr('origin');
        var url = orig + "/getsubtopics/" + selectedOption;
        $.ajax({
            url: url,
           success: function (response) {
                  var len = response.length;
                    $("#subtopicsId option[value!='']").remove(); // keep first 
                    for (var i = 0; i < len; i++) {
                        var id = response[i]['baseIdentity']['id'];
                        var name = response[i]['name'];
                        $("#subtopicsId").append("<option value='" + id + "'>" + name + "</option>");
                    }
                },
                error: function (e) {
                    console.log("ERROR : ", e);
                }
        });
    }
}).change(); // and call it once defined

The initial call of change() makes sure it will be executed on page re-load or if a value has been preselected by some initialization in the backend.

BTW: I am using "manual" form validation (see "is-valid"/"is-invalid"), because I (and users) didn't like that BS4 marks non-required empty fields as green. But that's byond scope of this Q and if you are interested then I can post it also.

What does "zend_mm_heap corrupted" mean

I am writing a php extension and also encounter this problem. When i call an extern function with complicated parameters from my extension, this error pop up.

The reason is my not allocating memory for a parameter(char *) in the extern function. If you are writing same kind of extension, please pay attention to this.

How to copy a file along with directory structure/path using python?

take a look at shutil. shutil.copyfile(src, dst) will copy a file to another file.

Note that shutil.copyfile will not create directories that do not already exist. for that, use os.makedirs

Browser Caching of CSS files

That depends on what headers you are sending along with your CSS files. Check your server configuration as you are probably not sending them manually. Do a google search for "http caching" to learn about different caching options you can set. You can force the browser to download a fresh copy of the file everytime it loads it for instance, or you can cache the file for one week...

A quick and easy way to join array elements with a separator (the opposite of split) in Java

You can use replace and replaceAll with regular expressions.

String[] strings = {"a", "b", "c"};

String result = Arrays.asList(strings).toString().replaceAll("(^\\[|\\]$)", "").replace(", ", ",");

Because Arrays.asList().toString() produces: "[a, b, c]", we do a replaceAll to remove the first and last brackets and then (optionally) you can change the ", " sequence for "," (your new separator).

A stripped version (fewer chars):

String[] strings = {"a", "b", "c"};

String result = ("" + Arrays.asList(strings)).replaceAll("(^.|.$)", "").replace(", ", "," );

Regular expressions are very powerful, specially String methods "replaceFirst" and "replaceAll". Give them a try.

Intel's HAXM equivalent for AMD on Windows OS

On my Mobo (ASRock A320M-HD with Ryzen 3 2200G) I have to:

SR-IOV support: enabled
IOMMU: enabled
SVM: enabled

On the OS enable Hyper V.

Resizing an Image without losing any quality

Here is a forum thread that provides a C# image resizing code sample. You could use one of the GD library binders to do resampling in C#.

How to use a keypress event in AngularJS?

(function(angular) {
  'use strict';
angular.module('dragModule', [])
  .directive('myDraggable', ['$document', function($document) {
    return {
      link: function(scope, element, attr) {
         element.bind("keydown keypress", function (event) {
           console.log('keydown keypress', event.which);
            if(event.which === 13) {
                event.preventDefault();
            }
        });
      }
    };
  }]);
})(window.angular);

Could not read JSON: Can not deserialize instance of hello.Country[] out of START_OBJECT token

Another solution:

public class CountryInfoResponse {
  private List<Object> geonames;
}

Usage of a generic Object-List solved my problem, as there were other Datatypes like Boolean too.

How can I install a previous version of Python 3 in macOS using homebrew?

In case anyone face pip issue like below

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.

The root cause is openssl 1.1 doesn’t support python 3.6 anymore. So you need to install old version openssl 1.0

here is the solution:

brew uninstall --ignore-dependencies openssl
brew install https://github.com/tebelorg/Tump/releases/download/v1.0.0/openssl.rb

inject bean reference into a Quartz job in Spring?

Make sure your

AutowiringSpringBeanJobFactory extends SpringBeanJobFactory 

dependency is pulled from

    "org.springframework:spring-context-support:4..."

and NOT from

    "org.springframework:spring-support:2..."

It wanted me to use

@Override
public Job newJob(TriggerFiredBundle bundle, Scheduler scheduler)

instead of

@Override
protected Object createJobInstance(final TriggerFiredBundle bundle)

so was failing to autowire job instance.

Github "Updates were rejected because the remote contains work that you do not have locally."

The error possibly comes because of the different structure of the code that you are committing and that present on GitHub. It creates conflicts which can be solved by

git pull

Merge conflicts resolving:

git push

If you confirm that your new code is all fine you can use:

git push -f origin master

Where -f stands for "force commit".

Table fixed header and scrollable body

Now that “all” browsers support ES6, I’ve incorporated the various suggestions above into a JavaScript class that takes a table as an argument and makes the body scrollable. It lets the browser’s layout engine determine header and body cell widths, and then makes the column widths match each other.

The height of a table can be set explicitly, or made to fill the remaining part of the browser window, and provides callbacks for events such as viewport resizing and/or details elements opening or closing.

Multi-row header support is available, and is especially effective if the table uses the id/headers attributes for accessibility as specified in the WCAC Guidelines, which is not as onerous a requirement as it might seem.

The code does not depend on any libraries, but plays nicely with them if they are being used. (Tested on pages that use JQuery).

The code and sample usage are available on Github.

Recover SVN password from local cache

Your SVN passwords in Ubuntu (12.04) are in:

~/.subversion/auth/svn.simple/

However in newer versions they are encrypted, as earlier someone mentioned. To find gnome-keyring passwords, I suggest You to use 'gkeyring' program.

To install it on Ubuntu – add repository :

sudo add-apt-repository ppa:kampka/ppa
sudo apt-get update

Install it:

sudo apt-get install gkeyring

And run as following:

gkeyring --id 15 --output=name,secret

Try different key ids to find pair matching what you are looking for. Thanks to kampka for the soft.

How to run a PowerShell script without displaying a window?

Here's an approach that that doesn't require command line args or a separate launcher. It's not completely invisible because a window does show momentarily at startup. But it then quickly vanishes. Where that's OK, this is, I think, the easiest approach if you want to launch your script by double-clicking in explorer, or via a Start menu shortcut (including, of course the Startup submenu). And I like that it's part of the code of the script itself, not something external.

Put this at the front of your script:

$t = '[DllImport("user32.dll")] public static extern bool ShowWindow(int handle, int state);'
add-type -name win -member $t -namespace native
[native.win]::ShowWindow(([System.Diagnostics.Process]::GetCurrentProcess() | Get-Process).MainWindowHandle, 0)

How to Populate a DataTable from a Stored Procedure

You can use a SqlDataAdapter:

    SqlDataAdapter adapter = new SqlDataAdapter();
    SqlCommand cmd = new SqlCommand("usp_GetABCD", sqlcon);
    cmd.CommandType = CommandType.StoredProcedure;
    adapter.SelectCommand = cmd;
    DataTable dt = new DataTable();
    adapter.Fill(dt);

Entity Framework - Code First - Can't Store List<String>

Just to simplify -

Entity framework doesn't support primitives. You either create a class to wrap it or add another property to format the list as a string:

public ICollection<string> List { get; set; }
public string ListString
{
    get { return string.Join(",", List); }
    set { List = value.Split(',').ToList(); }
}

How to float 3 divs side by side using CSS?

It is same way as you do for the two divs, just float the third one to left or right too.

<style>
  .left{float:left; width:33%;}
</style>

<div class="left">...</div>
<div class="left">...</div>
<div class="left">...</div>

CASE WHEN statement for ORDER BY clause

Another simple example from here..

SELECT * FROM dbo.Employee
ORDER BY 
 CASE WHEN Gender='Male' THEN EmployeeName END Desc,
 CASE WHEN Gender='Female' THEN Country END ASC

How to avoid warning when introducing NAs by coercion

suppressWarnings() has already been mentioned. An alternative is to manually convert the problematic characters to NA first. For your particular problem, taRifx::destring does just that. This way if you get some other, unexpected warning out of your function, it won't be suppressed.

> library(taRifx)
> x <- as.numeric(c("1", "2", "X"))
Warning message:
NAs introduced by coercion 
> y <- destring(c("1", "2", "X"))
> y
[1]  1  2 NA
> x
[1]  1  2 NA

Inline CSS styles in React: how to implement a:hover?

The simple way is using ternary operator

var Link = React.createClass({
  getInitialState: function(){
    return {hover: false}
  },
  toggleHover: function(){
    this.setState({hover: !this.state.hover})
  },
  render: function() {
    var linkStyle;
    if (this.state.hover) {
      linkStyle = {backgroundColor: 'red'}
    } else {
      linkStyle = {backgroundColor: 'blue'}
    }
    return(
      <div>
        <a style={this.state.hover ? {"backgroundColor": 'red'}: {"backgroundColor": 'blue'}} onMouseEnter={this.toggleHover} onMouseLeave={this.toggleHover}>Link</a>
      </div>
    )
  }

How do I find the index of a character within a string in C?

You can also use strcspn(string, "e") but this may be much slower since it's able to handle searching for multiple possible characters. Using strchr and subtracting the pointer is the best way.

How can you integrate a custom file browser/uploader with CKEditor?

Start by registering your custom browser/uploader when you instantiate CKEditor.

<script type="text/javascript">
CKEDITOR.replace('content', {
    filebrowserUploadUrl: "Upload File Url",//http://localhost/phpwork/test/ckFileUpload.php
    filebrowserWindowWidth  : 800,
    filebrowserWindowHeight : 500
});
</script>

Code for upload file(ckFileUpload.php) & put the upload file on root dir of your project.

// HERE SET THE PATH TO THE FOLDERS FOR IMAGES AND AUDIO ON YOUR SERVER (RELATIVE TO THE ROOT OF YOUR WEBSITE ON SERVER)

$upload_dir = array(
 'img'=> '/phpwork/test/uploads/editor-images/',
 'audio'=> '/phpwork/ezcore_v1/uploads/editor-images/'
);

// HERE PERMISSIONS FOR IMAGE
$imgset = array(
 'maxsize' => 2000,     // maximum file size, in KiloBytes (2 MB)
 'maxwidth' => 900,     // maximum allowed width, in pixels
 'maxheight' => 800,    // maximum allowed height, in pixels
 'minwidth' => 10,      // minimum allowed width, in pixels
 'minheight' => 10,     // minimum allowed height, in pixels
 'type' => array('bmp', 'gif', 'jpg', 'jpeg', 'png'),  // allowed extensions
);

// HERE PERMISSIONS FOR AUDIO
$audioset = array(
 'maxsize' => 20000,    // maximum file size, in KiloBytes (20 MB)
 'type' => array('mp3', 'ogg', 'wav'),  // allowed extensions
);

// If 1 and filename exists, RENAME file, adding "_NR" to the end of filename (name_1.ext, name_2.ext, ..)
// If 0, will OVERWRITE the existing file
define('RENAME_F', 1);

$re = '';
if(isset($_FILES['upload']) && strlen($_FILES['upload']['name']) >1) {
  define('F_NAME', preg_replace('/\.(.+?)$/i', '', basename($_FILES['upload']['name'])));  //get filename without extension

  // get protocol and host name to send the absolute image path to CKEditor
  $protocol = !empty($_SERVER['HTTPS']) ? 'https://' : 'http://';
  $site = $protocol. $_SERVER['SERVER_NAME'] .'/';
  $sepext = explode('.', strtolower($_FILES['upload']['name']));
  $type = end($sepext);    // gets extension
  $upload_dir = in_array($type, $imgset['type']) ? $upload_dir['img'] : $upload_dir['audio'];
  $upload_dir = trim($upload_dir, '/') .'/';

  //checkings for image or audio
  if(in_array($type, $imgset['type'])){
    list($width, $height) = getimagesize($_FILES['upload']['tmp_name']);  // image width and height
    if(isset($width) && isset($height)) {
      if($width > $imgset['maxwidth'] || $height > $imgset['maxheight']) $re .= '\\n Width x Height = '. $width .' x '. $height .' \\n The maximum Width x Height must be: '. $imgset['maxwidth']. ' x '. $imgset['maxheight'];
      if($width < $imgset['minwidth'] || $height < $imgset['minheight']) $re .= '\\n Width x Height = '. $width .' x '. $height .'\\n The minimum Width x Height must be: '. $imgset['minwidth']. ' x '. $imgset['minheight'];
      if($_FILES['upload']['size'] > $imgset['maxsize']*1000) $re .= '\\n Maximum file size must be: '. $imgset['maxsize']. ' KB.';
    }
  }
  else if(in_array($type, $audioset['type'])){
    if($_FILES['upload']['size'] > $audioset['maxsize']*1000) $re .= '\\n Maximum file size must be: '. $audioset['maxsize']. ' KB.';
  }
  else $re .= 'The file: '. $_FILES['upload']['name']. ' has not the allowed extension type.';

  //set filename; if file exists, and RENAME_F is 1, set "img_name_I"
  // $p = dir-path, $fn=filename to check, $ex=extension $i=index to rename
  function setFName($p, $fn, $ex, $i){
    if(RENAME_F ==1 && file_exists($p .$fn .$ex)) return setFName($p, F_NAME .'_'. ($i +1), $ex, ($i +1));
    else return $fn .$ex;
  }

  $f_name = setFName($_SERVER['DOCUMENT_ROOT'] .'/'. $upload_dir, F_NAME, ".$type", 0);
  $uploadpath = $_SERVER['DOCUMENT_ROOT'] .'/'. $upload_dir . $f_name;  // full file path

  // If no errors, upload the image, else, output the errors
  if($re == '') {
    if(move_uploaded_file($_FILES['upload']['tmp_name'], $uploadpath)) {
      $CKEditorFuncNum = $_GET['CKEditorFuncNum'];
      $url = $site. $upload_dir . $f_name;
      $msg = F_NAME .'.'. $type .' successfully uploaded: \\n- Size: '. number_format($_FILES['upload']['size']/1024, 2, '.', '') .' KB';
      $re = in_array($type, $imgset['type']) ? "window.parent.CKEDITOR.tools.callFunction($CKEditorFuncNum, '$url', '$msg')"  //for img
       : 'var cke_ob = window.parent.CKEDITOR; for(var ckid in cke_ob.instances) { if(cke_ob.instances[ckid].focusManager.hasFocus) break;} cke_ob.instances[ckid].insertHtml(\'<audio src="'. $url .'" controls></audio>\', \'unfiltered_html\'); alert("'. $msg .'"); var dialog = cke_ob.dialog.getCurrent();  dialog.hide();';
    }
    else $re = 'alert("Unable to upload the file")';
  }
  else $re = 'alert("'. $re .'")';
}

@header('Content-type: text/html; charset=utf-8');
echo '<script>'. $re .';</script>';

Ck-editor documentation is not clear after doing alot of R&D for custom file upload finally i have found this solution. It work for me and i hope it will helpful to others as well.

Correct way to push into state array

This Code work for me :

fetch('http://localhost:8080')
  .then(response => response.json())
  .then(json => {
  this.setState({mystate: this.state.mystate.push.apply(this.state.mystate, json)})
})

How to get database structure in MySQL via query

Take a look at the INFORMATION_SCHEMA.TABLES table. It contains metadata about all your tables.

Example:

SELECT * FROM `INFORMATION_SCHEMA`.`TABLES`
WHERE TABLE_NAME LIKE 'table1'

The advantage of this over other methods is that you can easily use queries like the one above as subqueries in your other queries.

Format ints into string of hex

Example with some beautifying, similar to the sep option available in python 3.8

def prettyhex(nums, sep=''):
    return sep.join(f'{a:02x}' for a in nums)

numbers = [0, 1, 2, 3, 127, 200, 255]
print(prettyhex(numbers,'-'))

output

00-01-02-03-7f-c8-ff

Reference excel worksheet by name?

There are several options, including using the method you demonstrate, With, and using a variable.

My preference is option 4 below: Dim a variable of type Worksheet and store the worksheet and call the methods on the variable or pass it to functions, however any of the options work.

Sub Test()
  Dim SheetName As String
  Dim SearchText As String
  Dim FoundRange As Range

  SheetName = "test"      
  SearchText = "abc"

  ' 0. If you know the sheet is the ActiveSheet, you can use if directly.
  Set FoundRange = ActiveSheet.UsedRange.Find(What:=SearchText)
  ' Since I usually have a lot of Subs/Functions, I don't use this method often.
  ' If I do, I store it in a variable to make it easy to change in the future or
  ' to pass to functions, e.g.: Set MySheet = ActiveSheet
  ' If your methods need to work with multiple worksheets at the same time, using
  ' ActiveSheet probably isn't a good idea and you should just specify the sheets.

  ' 1. Using Sheets or Worksheets (Least efficient if repeating or calling multiple times)
  Set FoundRange = Sheets(SheetName).UsedRange.Find(What:=SearchText)
  Set FoundRange = Worksheets(SheetName).UsedRange.Find(What:=SearchText)

  ' 2. Using Named Sheet, i.e. Sheet1 (if Worksheet is named "Sheet1"). The
  ' sheet names use the title/name of the worksheet, however the name must
  ' be a valid VBA identifier (no spaces or special characters. Use the Object
  ' Browser to find the sheet names if it isn't obvious. (More efficient than #1)
  Set FoundRange = Sheet1.UsedRange.Find(What:=SearchText)

  ' 3. Using "With" (more efficient than #1)
  With Sheets(SheetName)
    Set FoundRange = .UsedRange.Find(What:=SearchText)
  End With
  ' or possibly...
  With Sheets(SheetName).UsedRange
    Set FoundRange = .Find(What:=SearchText)
  End With

  ' 4. Using Worksheet variable (more efficient than 1)
  Dim MySheet As Worksheet
  Set MySheet = Worksheets(SheetName)
  Set FoundRange = MySheet.UsedRange.Find(What:=SearchText)

  ' Calling a Function/Sub
  Test2 Sheets(SheetName) ' Option 1
  Test2 Sheet1 ' Option 2
  Test2 MySheet ' Option 4

End Sub

Sub Test2(TestSheet As Worksheet)
    Dim RowIndex As Long
    For RowIndex = 1 To TestSheet.UsedRange.Rows.Count
        If TestSheet.Cells(RowIndex, 1).Value = "SomeValue" Then
            ' Do something
        End If
    Next RowIndex
End Sub

Shuffling a list of objects

The shuffling process is "with replacement", so the occurrence of each item may change! At least when when items in your list is also list.

E.g.,

ml = [[0], [1]] * 10

After,

random.shuffle(ml)

The number of [0] may be 9 or 8, but not exactly 10.

Access Form - Syntax error (missing operator) in query expression

Put [] around any field names that had spaces (as Dreden says) and save your query, close it and reopen it.

Using Access 2016, I still had the error message on new queries after I added [] around any field names... until the Query was saved.

Once the Query is saved (and visible in the Objects' List), closed and reopened, the error message disappears. This seems to be a bug from Access.

Docker official registry (Docker Hub) URL

The registry path for official images (without a slash in the name) is library/<image>. Try this instead:

docker pull registry.hub.docker.com/library/busybox

Match all elements having class name starting with a specific string

The following should do the trick:

div[class^='myclass'], div[class*=' myclass']{
    color: #F00;
}

Edit: Added wildcard (*) as suggested by David

How to create a DB for MongoDB container on start up?

If you are looking to remove usernames and passwords from your docker-compose.yml you can use Docker Secrets, here is how I have approached it.

version: '3.6'

services:
  db:
    image: mongo:3
    container_name: mycontainer
  secrets:
    - MONGO_INITDB_ROOT_USERNAME
    - MONGO_INITDB_ROOT_PASSWORD
  environment:
    - MONGO_INITDB_ROOT_USERNAME_FILE=/var/run/secrets/MONGO_INITDB_ROOT_USERNAME
    - MONGO_INITDB_ROOT_PASSWORD_FILE=/var/run/secrets/MONGO_INITDB_ROOT_PASSWORD
secrets:
  MONGO_INITDB_ROOT_USERNAME:
    file:  secrets/${NODE_ENV}_mongo_root_username.txt
  MONGO_INITDB_ROOT_PASSWORD:
    file:  secrets/${NODE_ENV}_mongo_root_password.txt

I have use the file: option for my secrets however, you can also use external: and use the secrets in a swarm.

The secrets are available to any script in the container at /var/run/secrets

The Docker documentation has this to say about storing sensitive data...

https://docs.docker.com/engine/swarm/secrets/

You can use secrets to manage any sensitive data which a container needs at runtime but you don’t want to store in the image or in source control, such as:

Usernames and passwords TLS certificates and keys SSH keys Other important data such as the name of a database or internal server Generic strings or binary content (up to 500 kb in size)

Python - List of unique dictionaries

In case the dictionaries are only uniquely identified by all items (ID is not available) you can use the answer using JSON. The following is an alternative that does not use JSON, and will work as long as all dictionary values are immutable

[dict(s) for s in set(frozenset(d.items()) for d in L)]

How to apply bold text style for an entire row using Apache POI?

This work for me

I set style's font before and make rowheader normally then i set in loop for the style with font bolded on each cell of rowhead. Et voilà first row is bolded.

HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("FirstSheet");
HSSFRow rowhead = sheet.createRow(0); 
HSSFCellStyle style = wb.createCellStyle();
HSSFFont font = wb.createFont();
font.setFontName(HSSFFont.FONT_ARIAL);
font.setFontHeightInPoints((short)10);
font.setBold(true);
style.setFont(font);
rowhead.createCell(0).setCellValue("ID");
rowhead.createCell(1).setCellValue("First");
rowhead.createCell(2).setCellValue("Second");
rowhead.createCell(3).setCellValue("Third");
for(int j = 0; j<=3; j++)
rowhead.getCell(j).setCellStyle(style);

Force unmount of NFS-mounted directory

Your NFS server disappeared.

Ideally your best bet is if the NFS server comes back.

If not, the "umount -f" should have done the trick. It doesn't ALWAYS work, but it often will.

If you happen to know what processes are USING the NFS filesystem, you could try killing those processes and then maybe an unmount would work.

Finally, I'd guess you need to reboot.

Also, DON'T soft-mount your NFS drives. You use hard-mounts to guarantee that they worked. That's necessary if you're doing writes.

Get selected value of a dropdown's item using jQuery

This is what works

    var value= $('option:selected', $('#dropDownId')).val();

ascending/descending in LINQ - can one change the order via parameter?

In terms of how this is implemented, this changes the method - from OrderBy/ThenBy to OrderByDescending/ThenByDescending. However, you can apply the sort separately to the main query...

var qry = from .... // or just dataList.AsEnumerable()/AsQueryable()

if(sortAscending) {
    qry = qry.OrderBy(x=>x.Property);
} else {
    qry = qry.OrderByDescending(x=>x.Property);
}

Any use? You can create the entire "order" dynamically, but it is more involved...

Another trick (mainly appropriate to LINQ-to-Objects) is to use a multiplier, of -1/1. This is only really useful for numeric data, but is a cheeky way of achieving the same outcome.

warning: incompatible implicit declaration of built-in function ‘xyz’

Here is some C code that produces the above mentioned error:

int main(int argc, char **argv) {
  exit(1);
}

Compiled like this on Fedora 17 Linux 64 bit with gcc:

el@defiant ~/foo2 $ gcc -o n n2.c                                                               
n2.c: In function ‘main’:
n2.c:2:3: warning: incompatible implicit declaration of built-in 
function ‘exit’ [enabled by default]
el@defiant ~/foo2 $ ./n 
el@defiant ~/foo2 $ 

To make the warning go away, add this declaration to the top of the file:

#include <stdlib.h>

T-SQL Format integer to 2-digit string

Here is tiny function that left pad value with a given padding char You can specify how many characters to be padded to left..

   Create    function fsPadLeft(@var varchar(200),@padChar char(1)='0',@len int)
      returns varchar(300)
    as
    Begin
      return replicate(@PadChar,@len-Len(@var))+@var
    end

To call :

declare @value int; set @value =2
select dbo.fsPadLeft(@value,'0',2)

How can I create tests in Android Studio?

Android Studio v.2.3.3

Highlight the code context you want to test, and use the hotkey: CTRL+SHIFT+T

Use the dialog interface to complete your setup.

The testing framework is supposed to mirror your project package layout for best results, but you can manually create custom tests, provided you have the correct directory and build settings.

Convert floats to ints in Pandas?

To convert all float columns to int

>>> df = pd.DataFrame(np.random.rand(5, 4) * 10, columns=list('PQRS'))
>>> print(df)
...     P           Q           R           S
... 0   4.395994    0.844292    8.543430    1.933934
... 1   0.311974    9.519054    6.171577    3.859993
... 2   2.056797    0.836150    5.270513    3.224497
... 3   3.919300    8.562298    6.852941    1.415992
... 4   9.958550    9.013425    8.703142    3.588733

>>> float_col = df.select_dtypes(include=['float64']) # This will select float columns only
>>> # list(float_col.columns.values)

>>> for col in float_col.columns.values:
...     df[col] = df[col].astype('int64')

>>> print(df)
...     P   Q   R   S
... 0   4   0   8   1
... 1   0   9   6   3
... 2   2   0   5   3
... 3   3   8   6   1
... 4   9   9   8   3

How to get exception message in Python properly

I had the same problem. I think the best solution is to use log.exception, which will automatically print out stack trace and error message, such as:

try:
    pass
    log.info('Success')
except:
    log.exception('Failed')

Convert double/float to string

I know maybe it is unnecessary, but I made a function which converts float to string:

CODE:

#include <stdio.h>

/** Number on countu **/

int n_tu(int number, int count)
{
    int result = 1;
    while(count-- > 0)
        result *= number;

    return result;
}

/*** Convert float to string ***/
void float_to_string(float f, char r[])
{
    long long int length, length2, i, number, position, sign;
    float number2;

    sign = -1;   // -1 == positive number
    if (f < 0)
    {
        sign = '-';
        f *= -1;
    }

    number2 = f;
    number = f;
    length = 0;  // Size of decimal part
    length2 = 0; // Size of tenth

    /* Calculate length2 tenth part */
    while( (number2 - (float)number) != 0.0 && !((number2 - (float)number) < 0.0) )
    {
         number2 = f * (n_tu(10.0, length2 + 1));
         number = number2;

         length2++;
    }

    /* Calculate length decimal part */
    for (length = (f > 1) ? 0 : 1; f > 1; length++)
        f /= 10;

    position = length;
    length = length + 1 + length2;
    number = number2;
    if (sign == '-')
    {
        length++;
        position++;
    }

    for (i = length; i >= 0 ; i--)
    {
        if (i == (length))
            r[i] = '\0';
        else if(i == (position))
            r[i] = '.';
        else if(sign == '-' && i == 0)
            r[i] = '-';
        else
        {
            r[i] = (number % 10) + '0';
            number /=10;
        }
    }
}

Update style of a component onScroll in React.js

Here is another example using HOOKS fontAwesomeIcon and Kendo UI React
[![screenshot here][1]][1]

import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';


const ScrollBackToTop = () => {
  const [show, handleShow] = useState(false);

  useEffect(() => {
    window.addEventListener('scroll', () => {
      if (window.scrollY > 1200) {
        handleShow(true);
      } else handleShow(false);
    });
    return () => {
      window.removeEventListener('scroll');
    };
  }, []);

  const backToTop = () => {
    window.scroll({ top: 0, behavior: 'smooth' });
  };

  return (
    <div>
      {show && (
      <div className="backToTop text-center">
        <button className="backToTop-btn k-button " onClick={() => backToTop()} >
          <div className="d-none d-xl-block mr-1">Top</div>
          <FontAwesomeIcon icon="chevron-up"/>
        </button>
      </div>
      )}
    </div>
  );
};

export default ScrollBackToTop;```


  [1]: https://i.stack.imgur.com/ZquHI.png

Convert number to month name in PHP

A simple tricks here you can use strtotime() function workable as per your need, a convert number to month name.

1.If you want a result in Jan, Feb and Mar Then try below one with the 'M' as a parameter inside the date.

$month=5;
$nmonth = date('M',strtotime("01-".$month."-".date("Y")));
echo $nmonth;

Output : May

/2. You can try with the 'F' instead of 'M' to get the full month name as an output January February March etc.

$month=1;
$nmonth = date('M',strtotime("01-".$month."-".date("Y")));
echo $nmonth;

Output : January

Retrieving a Foreign Key value with django-rest-framework serializers

Worked on 08/08/2018 and on DRF version 3.8.2:

class ItemSerializer(serializers.ModelSerializer):
    category_name = serializers.ReadOnlyField(source='category.name')

    class Meta:
        model = Item
        read_only_fields = ('id', 'category_name')
        fields = ('id', 'category_name', 'name',)

Using the Meta read_only_fields we can declare exactly which fields should be read_only. Then we need to declare the foreign field on the Meta fields (better be explicit as the mantra goes: zen of python).

how can I Update top 100 records in sql server

Note, the parentheses are required for UPDATE statements:

update top (100) table1 set field1 = 1

Pdf.js: rendering a pdf file using a base64 file source instead of url

According to the examples base64 encoding is directly supported, although I've not tested it myself. Take your base64 string (derived from a file or loaded with any other method, POST/GET, websockets etc), turn it to a binary with atob, and then parse this to getDocument on the PDFJS API likePDFJS.getDocument({data: base64PdfData}); Codetoffel answer does work just fine for me though.

MVC4 input field placeholder

There are such of ways to Bind a Placeholder to View:

1) With use of MVC Data Annotations:

Model:

[Required]
[Display(Prompt = "Enter Your First Name")]
public string FirstName { get; set; }

Razor Syntax:

@Html.TextBoxFor(m => m.FirstName, new { placeholder = @Html.DisplayNameFor(n => n.UserName)})

2) With use of MVC Data Annotations But with DisplayName:

Model:

[Required]
[DisplayName("Enter Your First Name")]
public string FirstName { get; set; }

Razor Syntax:

@Html.TextBoxFor(m => m.FirstName, new { placeholder = @Html.DisplayNameFor(n => n.UserName)})

3) Without use of MVC Data Annotation (recommended):

Razor Syntax:

@Html.TextBoxFor(m => m.FirstName, new { @placeholder = "Enter Your First Name")

How do you transfer or export SQL Server 2005 data to Excel

SSIS is a no-brainer for doing stuff like this and is very straight forward (and this is just the kind of thing it is for).

  1. Right-click the database in SQL Management Studio
  2. Go to Tasks and then Export data, you'll then see an easy to use wizard.
  3. Your database will be the source, you can enter your SQL query
  4. Choose Excel as the target
  5. Run it at end of wizard

If you wanted, you could save the SSIS package as well (there's an option at the end of the wizard) so that you can do it on a schedule or something (and even open and modify to add more functionality if needed).

json_encode(): Invalid UTF-8 sequence in argument

I am very late but if some one working on SLIM to make rest api and getting same error can solve this problem by adding below line as:

<?php

// DbConnect.php file
class DbConnect
{
    //Variable to store database link
    private $con;

    //Class constructor
    function __construct()
    {

    }

    //This method will connect to the database
    function connect()
    {
        //Including the constants.php file to get the database constants
        include_once dirname(__FILE__) . '/Constants.php';

        //connecting to mysql database
        $this->con = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);

        mysqli_set_charset($this->con, "utf8"); // add this line 
        //Checking if any error occured while connecting
        if (mysqli_connect_errno()) {
            echo "Failed to connect to MySQL: " . mysqli_connect_error();
        }

        //finally returning the connection link
        return $this->con;
    }
}

Is there a Python equivalent to Ruby's string interpolation?

Python 3.6 will add literal string interpolation similar to Ruby's string interpolation. Starting with that version of Python (which is scheduled to be released by the end of 2016), you will be able to include expressions in "f-strings", e.g.

name = "Spongebob Squarepants"
print(f"Who lives in a Pineapple under the sea? {name}.")

Prior to 3.6, the closest you can get to this is

name = "Spongebob Squarepants"
print("Who lives in a Pineapple under the sea? %(name)s." % locals())

The % operator can be used for string interpolation in Python. The first operand is the string to be interpolated, the second can have different types including a "mapping", mapping field names to the values to be interpolated. Here I used the dictionary of local variables locals() to map the field name name to its value as a local variable.

The same code using the .format() method of recent Python versions would look like this:

name = "Spongebob Squarepants"
print("Who lives in a Pineapple under the sea? {name!s}.".format(**locals()))

There is also the string.Template class:

tmpl = string.Template("Who lives in a Pineapple under the sea? $name.")
print(tmpl.substitute(name="Spongebob Squarepants"))

List distinct values in a vector in R

another way would be to use dplyr package:

x = c(1,1,2,3,4,4,4)
dplyr::distinct(as.data.frame(x))

YAML equivalent of array of objects in JSON

TL;DR

You want this:

AAPL:
  - shares: -75.088
    date: 11/27/2015
  - shares: 75.088
    date: 11/26/2015

Mappings

The YAML equivalent of a JSON object is a mapping, which looks like these:

# flow style
{ foo: 1, bar: 2 }
# block style
foo: 1
bar: 2

Note that the first characters of the keys in a block mapping must be in the same column. To demonstrate:

# OK
   foo: 1
   bar: 2
# Parse error
   foo: 1
    bar: 2

Sequences

The equivalent of a JSON array in YAML is a sequence, which looks like either of these (which are equivalent):

# flow style
[ foo bar, baz ]
# block style
- foo bar
- baz

In a block sequence the -s must be in the same column.

JSON to YAML

Let's turn your JSON into YAML. Here's your JSON:

{"AAPL": [
  {
    "shares": -75.088,
    "date": "11/27/2015"
  },
  {
    "shares": 75.088,
    "date": "11/26/2015"
  },
]}

As a point of trivia, YAML is a superset of JSON, so the above is already valid YAML—but let's actually use YAML's features to make this prettier.

Starting from the inside out, we have objects that look like this:

{
  "shares": -75.088,
  "date": "11/27/2015"
}

The equivalent YAML mapping is:

shares: -75.088
date: 11/27/2015

We have two of these in an array (sequence):

- shares: -75.088
  date: 11/27/2015
- shares: 75.088
  date: 11/26/2015

Note how the -s line up and the first characters of the mapping keys line up.

Finally, this sequence is itself a value in a mapping with the key AAPL:

AAPL:
  - shares: -75.088
    date: 11/27/2015
  - shares: 75.088
    date: 11/26/2015

Parsing this and converting it back to JSON yields the expected result:

{
  "AAPL": [
    {
      "date": "11/27/2015", 
      "shares": -75.088
    }, 
    {
      "date": "11/26/2015", 
      "shares": 75.088
    }
  ]
}

You can see it (and edit it interactively) here.

How to rename files and folder in Amazon S3?

To rename a folder (which is technically a set of objects with a common prefix as key) you can use the aws cli move command with --recursive option.

aws s3 mv s3://bucket/old_folder s3://bucket/new_folder --recursive

How do I check if a given string is a legal/valid file name under Windows?

Also the destination file system is important.

Under NTFS, some files can not be created in specific directories. E.G. $Boot in root

Vim multiline editing like in sublimetext?

My solution is to use these 2 mappings:

map <leader>n <Esc><Esc>0qq
map <leader>m q:'<,'>-1normal!@q<CR><Down>

How to use them:

  1. Select your lines. If I want to select the next 12 lines I just press V12j
  2. Press <leader>n
  3. Make your changes to the line
  4. Make sure you're in normal mode and then press <leader>m

To make another edit you don't need to make the selection again. Just press <leader>n, make your edit and press <leader>m to apply.


How this works:

  • <Esc><Esc>0qq Exit the visual selection, go to the beginning of the line and start recording a macro.

  • q Stop recording the macro.

  • :'<,'>-1normal!@q<CR> From the start of the visual selection to the line before the end, play the macro on each line.

  • <Down> Go back down to the last line.


You can also just map the same key but for different modes:

vmap <leader>m <Esc><Esc>0qq
nmap <leader>m q:'<,'>-1normal!@q<CR><Down>

Although this messes up your ability to make another edit. You'll have to re-select your lines.

Changing the CommandTimeout in SQL Management studio

Right click in the query pane, select Query Options... and in the Execution->General section (the default when you first open it) there is an Execution time-out setting.

how to check for null with a ng-if values in a view with angularjs?

See the correct way with your example:

<div ng-if="!test.view">1</div>
<div ng-if="!!test.view">2</div>

Regards, Nicholls

How to concatenate strings in windows batch file for loop?

Try this, with strings:

set "var=string1string2string3"

and with string variables:

set "var=%string1%%string2%%string3%"

How to force composer to reinstall a library?

What I did:

  1. Deleted that particular library's folder
  2. composer update --prefer-source vendor/library-name

It fetches the library again along with it's git repo

How do I disable and re-enable a button in with javascript?

you can try with

document.getElementById('btn').disabled = !this.checked"

_x000D_
_x000D_
<input type="submit" name="btn"  id="btn" value="submit" disabled/>_x000D_
_x000D_
<input type="checkbox"  onchange="document.getElementById('btn').disabled = !this.checked"/>
_x000D_
_x000D_
_x000D_

Share application "link" in Android

Call this method:

public static void shareApp(Context context)
{
    final String appPackageName = context.getPackageName();
    Intent sendIntent = new Intent();
    sendIntent.setAction(Intent.ACTION_SEND);
    sendIntent.putExtra(Intent.EXTRA_TEXT, "Check out the App at: https://play.google.com/store/apps/details?id=" + appPackageName);
    sendIntent.setType("text/plain");
    context.startActivity(sendIntent);
}

How to Alter a table for Identity Specification is identity SQL Server

You can't alter the existing columns for identity.

You have 2 options,

Create a new table with identity & drop the existing table

Create a new column with identity & drop the existing column

Approach 1. (New table) Here you can retain the existing data values on the newly created identity column.

CREATE TABLE dbo.Tmp_Names
    (
      Id int NOT NULL
             IDENTITY(1, 1),
      Name varchar(50) NULL
    )
ON  [PRIMARY]
go

SET IDENTITY_INSERT dbo.Tmp_Names ON
go

IF EXISTS ( SELECT  *
            FROM    dbo.Names ) 
    INSERT  INTO dbo.Tmp_Names ( Id, Name )
            SELECT  Id,
                    Name
            FROM    dbo.Names TABLOCKX
go

SET IDENTITY_INSERT dbo.Tmp_Names OFF
go

DROP TABLE dbo.Names
go

Exec sp_rename 'Tmp_Names', 'Names'

Approach 2 (New column) You can’t retain the existing data values on the newly created identity column, The identity column will hold the sequence of number.

Alter Table Names
Add Id_new Int Identity(1, 1)
Go

Alter Table Names Drop Column ID
Go

Exec sp_rename 'Names.Id_new', 'ID', 'Column'

See the following Microsoft SQL Server Forum post for more details:

http://social.msdn.microsoft.com/forums/en-US/transactsql/thread/04d69ee6-d4f5-4f8f-a115-d89f7bcbc032

How to get the html of a div on another page with jQuery ajax?

Ok, You should "construct" the html and find the .content div.

like this:

$.ajax({
   url:href,
   type:'GET',
   success: function(data){
       $('#content').html($(data).find('#content').html());
   }
});

Simple!

How can I select an element by name with jQuery?

You can use any attribute as selector with [attribute_name=value].

$('td[name=tcol1]').hide();

A simple command line to download a remote maven2 artifact to the local repository?

Give them a trivial pom with these jars listed as dependencies and instructions to run:

mvn dependency:go-offline

This will pull the dependencies to the local repo.

A more direct solution is dependency:get, but it's a lot of arguments to type:

mvn dependency:get -DrepoUrl=something -Dartifact=group:artifact:version

Python Socket Multiple Clients

Here is the example from the SocketServer documentation which would make an excellent starting point

import SocketServer

class MyTCPHandler(SocketServer.BaseRequestHandler):
    """
    The RequestHandler class for our server.

    It is instantiated once per connection to the server, and must
    override the handle() method to implement communication to the
    client.
    """

    def handle(self):
        # self.request is the TCP socket connected to the client
        self.data = self.request.recv(1024).strip()
        print "{} wrote:".format(self.client_address[0])
        print self.data
        # just send back the same data, but upper-cased
        self.request.sendall(self.data.upper())

if __name__ == "__main__":
    HOST, PORT = "localhost", 9999

    # Create the server, binding to localhost on port 9999
    server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)

    # Activate the server; this will keep running until you
    # interrupt the program with Ctrl-C
    server.serve_forever()

Try it from a terminal like this

$ telnet localhost 9999
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Hello
HELLOConnection closed by foreign host.
$ telnet localhost 9999
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Sausage
SAUSAGEConnection closed by foreign host.

You'll probably need to use A Forking or Threading Mixin too

How to monitor Java memory usage?

The problem with system.gc, is that the JVM already automatically allocates time to the garbage collector based on memory usage.

However, if you are, for instance, working in a very memory limited condition, like a mobile device, System.gc allows you to manually allocate more time towards this garbage collection, but at the cost of cpu time (but, as you said, you aren't that concerned about performance issues of gc).

Best practice would probably be to only use it where you might be doing large amounts of deallocation (like flushing a large array).

All considered, since you are simply concerned about memory usage, feel free to call gc, or, better yet, see if it makes much of a memory difference in your case, and then decide.

Get DataKey values in GridView RowCommand

I managed to get the value of the DataKeys using this code:

In the GridView I added:

DataKeyNames="ID" OnRowCommand="myRowCommand"

Then in my row command function:

protected void myRowCommand(object sender, GridViewCommandEventArgs e) 
{
    LinkButton lnkBtn = (LinkButton)e.CommandSource;    // the button
    GridViewRow myRow = (GridViewRow)lnkBtn.Parent.Parent;  // the row
    GridView myGrid = (GridView)sender; // the gridview
    string ID = myGrid.DataKeys[myRow.RowIndex].Value.ToString(); // value of the datakey 

    switch (e.CommandName)
    {
      case "cmd1":
      // do something using the ID
      break;
      case "cmd2":
      // do something else using the ID
      break;
    }
 }

How to input a string from user into environment variable from batch file

You can use set with the /p argument:

SET /P variable=[promptString]

The /P switch allows you to set the value of a variable to a line of input entered by the user. Displays the specified promptString before reading the line of input. The promptString can be empty.

So, simply use something like

set /p Input=Enter some text: 

Later you can use that variable as argument to a command:

myCommand %Input%

Be careful though, that if your input might contain spaces it's probably a good idea to quote it:

myCommand "%Input%"

How to Insert BOOL Value to MySQL Database

TRUE and FALSE are keywords, and should not be quoted as strings:

INSERT INTO first VALUES (NULL, 'G22', TRUE);
INSERT INTO first VALUES (NULL, 'G23', FALSE);

By quoting them as strings, MySQL will then cast them to their integer equivalent (since booleans are really just a one-byte INT in MySQL), which translates into zero for any non-numeric string. Thus, you get 0 for both values in your table.

Non-numeric strings cast to zero:

mysql> SELECT CAST('TRUE' AS SIGNED), CAST('FALSE' AS SIGNED), CAST('12345' AS SIGNED);
+------------------------+-------------------------+-------------------------+
| CAST('TRUE' AS SIGNED) | CAST('FALSE' AS SIGNED) | CAST('12345' AS SIGNED) |
+------------------------+-------------------------+-------------------------+
|                      0 |                       0 |                   12345 |
+------------------------+-------------------------+-------------------------+

But the keywords return their corresponding INT representation:

mysql> SELECT TRUE, FALSE;
+------+-------+
| TRUE | FALSE |
+------+-------+
|    1 |     0 |
+------+-------+

Note also, that I have replaced your double-quotes with single quotes as are more standard SQL string enclosures. Finally, I have replaced your empty strings for id with NULL. The empty string may issue a warning.

Remove Trailing Spaces and Update in Columns in SQL Server

To just trim trailing spaces you should use

UPDATE
    TableName
SET
    ColumnName = RTRIM(ColumnName)

However, if you want to trim all leading and trailing spaces then use this

UPDATE
    TableName
SET
    ColumnName = LTRIM(RTRIM(ColumnName))

Proper usage of Java -D command-line parameters

That should be:

java -Dtest="true" -jar myApplication.jar

Then the following will return the value:

System.getProperty("test");

The value could be null, though, so guard against an exception using a Boolean:

boolean b = Boolean.parseBoolean( System.getProperty( "test" ) );

Note that the getBoolean method delegates the system property value, simplifying the code to:

if( Boolean.getBoolean( "test" ) ) {
   // ...
}

Case statement with multiple values in each 'when' block

You might take advantage of ruby's "splat" or flattening syntax.

This makes overgrown when clauses — you have about 10 values to test per branch if I understand correctly — a little more readable in my opinion. Additionally, you can modify the values to test at runtime. For example:

honda  = ['honda', 'acura', 'civic', 'element', 'fit', ...]
toyota = ['toyota', 'lexus', 'tercel', 'rx', 'yaris', ...]
...

if include_concept_cars
  honda += ['ev-ster', 'concept c', 'concept s', ...]
  ...
end

case car
when *toyota
  # Do something for Toyota cars
when *honda
  # Do something for Honda cars
...
end

Another common approach would be to use a hash as a dispatch table, with keys for each value of car and values that are some callable object encapsulating the code you wish to execute.

What is the correct way to declare a boolean variable in Java?

In your example, You don't need to. As a standard programming practice, all variables being referred to inside some code block, say for example try{} catch(){}, and being referred to outside the block as well, you need to declare the variables outside the try block first e.g.

This is helpful when your equals method call throws some exception e.g. NullPointerException;

     boolean isMatch = false;

     try{
         isMatch = email1.equals (email2);
      }catch(NullPointerException npe){
         .....
      }
      System.out.print("Match=="+isMatch);
      if(isMatch){
        ......
      }

Android image caching

Late answer, but I figured I should add a link to my site because I have written a tutorial how to make an image cache for android: http://squarewolf.nl/2010/11/android-image-cache/ Update: the page has been taken offline as the source was outdated. I join @elenasys in her advice to use Ignition.

So to all the people who stumble upon this question and haven't found a solution: hope you enjoy! =D

Where are $_SESSION variables stored?

How does it work? How does it know it's me?

Most sessions set a user-key(called the sessionid) on the user's computer that looks something like this: 765487cf34ert8dede5a562e4f3a7e12. Then, when a session is opened on another page, it scans the computer for a user-key and runs to the server to get your variables.

If you mistakenly clear the cache, then your user-key will also be cleared. You won't be able to get your variables from the server any more since you don't know your id.

port forwarding in windows

I've used this little utility whenever the need arises: http://www.analogx.com/contents/download/network/pmapper/freeware.htm

The last time this utility was updated was in 2009. I noticed on my Win10 machine, it hangs for a few seconds when opening new windows sometimes. Other then that UI glitch, it still does its job fine.

A reference to the dll could not be added

I just ran into that issue and after all the explanations about fixing it with command prompt I found that if you add it directly to the project you can then simply include the library on each page that it's needed

How to print HTML content on click of a button, but not the page?

Here is a pure css version

_x000D_
_x000D_
.example-print {_x000D_
    display: none;_x000D_
}_x000D_
@media print {_x000D_
   .example-screen {_x000D_
       display: none;_x000D_
    }_x000D_
    .example-print {_x000D_
       display: block;_x000D_
    }_x000D_
}
_x000D_
<div class="example-screen">You only see me in the browser</div>_x000D_
_x000D_
<div class="example-print">You only see me in the print</div>
_x000D_
_x000D_
_x000D_

Delete the last two characters of the String

You can use substring function:

s.substring(0,s.length() - 2));

With the first 0, you say to substring that it has to start in the first character of your string and with the s.length() - 2 that it has to finish 2 characters before the String ends.

For more information about substring function you can see here:

http://docs.oracle.com/javase/7/docs/api/java/lang/String.html

Docker error: invalid reference format: repository name must be lowercase

Let me emphasise that Docker doesn't even allow mixed characters.

Good: docker build -t myfirstechoimage:0.1 .

Bad: docker build -t myFirstEchoImage:0.1 .

Why Python 3.6.1 throws AttributeError: module 'enum' has no attribute 'IntFlag'?

When ever I got this problem:

AttributeError: module 'enum' has no attribute 'IntFlag'

simply first i run the command:

unset PYTHONPATH 

and then run my desired command then got success in that.

Get all object attributes in Python?

Use the built-in function dir().

Carriage return and Line feed... Are both required in C#?

System.Environment.NewLine is the constant you are looking for - http://msdn.microsoft.com/en-us/library/system.environment.newline.aspx which will provide environment specific combination that most programs on given OS will consider "next line of text".

In practice most of the text tools treat all variations that include \n as "new line" and you can just use it in your text "foo\nbar". Especially if you are trying to construct multi-line format strings like $"V1 = {value1}\nV2 = {value2}\n". If you are building text with string concatenation consider using NewLine. In any case make sure tools you are using understand output the way you want and you may need for example always use \r\n irrespective of platform if editor of your choice can't correctly open files otherwise.

Note that WriteLine methods use NewLine so if you plan to write text with one these methods avoid using just \n as resulting text may contain mix of \r\n and just \n which may confuse some tools and definitely does not look neat.

For historical background see Difference between \n and \r?

Java JDBC - How to connect to Oracle using Service Name instead of SID

You can also specify the TNS name in the JDBC URL as below

jdbc:oracle:thin:@(DESCRIPTION =(ADDRESS_LIST =(ADDRESS =(PROTOCOL=TCP)(HOST=blah.example.com)(PORT=1521)))(CONNECT_DATA=(SID=BLAHSID)(GLOBAL_NAME=BLAHSID.WORLD)(SERVER=DEDICATED)))

Can't access to HttpContext.Current

Have you included the System.Web assembly in the application?

using System.Web;

If not, try specifying the System.Web namespace, for example:

 System.Web.HttpContext.Current

Reading entire html file to String?

For string operations use StringBuilder or StringBuffer classes for accumulating string data blocks. Do not use += operations for string objects. String class is immutable and you will produce a large amount of string objects upon runtime and it will affect on performance.

Use .append() method of StringBuilder/StringBuffer class instance instead.

Why does JPA have a @Transient annotation?

I will try to answer the question of "why". Imagine a situation where you have a huge database with a lot of columns in a table, and your project/system uses tools to generate entities from database. (Hibernate has those, etc...) Now, suppose that by your business logic you need a particular field NOT to be persisted. You have to "configure" your entity in a particular way. While Transient keyword works on an object - as it behaves within a java language, the @Transient only designed to answer the tasks that pertains only to persistence tasks.

How can I add (simple) tracing in C#?

DotNetCoders has a starter article on it: http://www.dotnetcoders.com/web/Articles/ShowArticle.aspx?article=50. They talk about how to set up the switches in the configuration file and how to write the code, but it is pretty old (2002).

There's another article on CodeProject: A Treatise on Using Debug and Trace classes, including Exception Handling, but it's the same age.

CodeGuru has another article on custom TraceListeners: Implementing a Custom TraceListener

Plot size and resolution with R markdown, knitr, pandoc, beamer

I think that is a frequently asked question about the behavior of figures in beamer slides produced from Pandoc and markdown. The real problem is, R Markdown produces PNG images by default (from knitr), and it is hard to get the size of PNG images correct in LaTeX by default (I do not know why). It is fairly easy, however, to get the size of PDF images correct. One solution is to reset the default graphical device to PDF in your first chunk:

```{r setup, include=FALSE}
knitr::opts_chunk$set(dev = 'pdf')
```

Then all the images will be written as PDF files, and LaTeX will be happy.

Your second problem is you are mixing up the HTML units with LaTeX units in out.width / out.height. LaTeX and HTML are very different technologies. You should not expect \maxwidth to work in HTML, or 200px in LaTeX. Especially when you want to convert Markdown to LaTeX, you'd better not set out.width / out.height (use fig.width / fig.height and let LaTeX use the original size).

Show a div with Fancybox

As far as I know, an input element may not have a href attribute, which is where Fancybox gets its information about the content. The following code uses an a element instead of the input element. Also, this is what I would call the "standard way".

<html>
<head>
  <script type="text/javascript" charset="utf-8" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
  <script type="text/javascript" src="http://fancyapps.com/fancybox/source/jquery.fancybox.pack.js?v=2.0.5"></script>
  <link rel="stylesheet" type="text/css" href="http://fancyapps.com/fancybox/source/jquery.fancybox.css?v=2.0.5" media="screen" />
</head>
<body>

<a href="#divForm" id="btnForm">Load Form</a>

<div id="divForm" style="display:none">
  <form action="tbd">
    File: <input type="file" /><br /><br />
    <input type="submit" />
  </form>
</div>

<script type="text/javascript">
  $(function(){
    $("#btnForm").fancybox();
  });
</script>

</body>
</html>

See it in action on JSBin

Pycharm: run only part of my Python file

Pycharm shortcut for running "Selection" in the console is ALT + SHIFT + e

For this to work properly, you'll have to run everything this way.

enter image description here

Getting values from query string in an url using AngularJS $location

you can use this as well

function getParameterByName(name) {
    name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
    var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
        results = regex.exec(location.search);
    return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
}

var queryValue = getParameterByName('test_user_bLzgB');

Angular 5 Reactive Forms - Radio Button Group

I tried your code, you didn't assign/bind a value to your formControlName.

In HTML file:

<form [formGroup]="form">
   <label>
     <input type="radio" value="Male" formControlName="gender">
       <span>male</span>
   </label>
   <label>
     <input type="radio" value="Female" formControlName="gender">
       <span>female</span>
   </label>
</form>

In the TS file:

  form: FormGroup;
  constructor(fb: FormBuilder) {
    this.name = 'Angular2'
    this.form = fb.group({
      gender: ['', Validators.required]
    });
  }

Make sure you use Reactive form properly: [formGroup]="form" and you don't need the name attribute.

In my sample. words male and female in span tags are the values display along the radio button and Male and Female values are bind to formControlName

See the screenshot: enter image description here

To make it shorter:

<form [formGroup]="form">
  <input type="radio" value='Male' formControlName="gender" >Male
  <input type="radio" value='Female' formControlName="gender">Female
</form>

enter image description here

Hope it helps:)

Pandas dataframe groupby plot

Simple plot,

you can use:

df.plot(x='Date',y='adj_close')

Or you can set the index to be Date beforehand, then it's easy to plot the column you want:

df.set_index('Date', inplace=True)
df['adj_close'].plot()

If you want a chart with one series by ticker on it

You need to groupby before:

df.set_index('Date', inplace=True)
df.groupby('ticker')['adj_close'].plot(legend=True)

enter image description here


If you want a chart with individual subplots:

grouped = df.groupby('ticker')

ncols=2
nrows = int(np.ceil(grouped.ngroups/ncols))

fig, axes = plt.subplots(nrows=nrows, ncols=ncols, figsize=(12,4), sharey=True)

for (key, ax) in zip(grouped.groups.keys(), axes.flatten()):
    grouped.get_group(key).plot(ax=ax)

ax.legend()
plt.show()

enter image description here

Android Volley - BasicNetwork.performRequest: Unexpected response code 400

change

public static final String URL = "http://api-Location";

to

public static final String URL = "https://api-Location"

it's happen because i'm using 000webhostapp app

What is an idiomatic way of representing enums in Go?

Quoting from the language specs:Iota

Within a constant declaration, the predeclared identifier iota represents successive untyped integer constants. It is reset to 0 whenever the reserved word const appears in the source and increments after each ConstSpec. It can be used to construct a set of related constants:

const (  // iota is reset to 0
        c0 = iota  // c0 == 0
        c1 = iota  // c1 == 1
        c2 = iota  // c2 == 2
)

const (
        a = 1 << iota  // a == 1 (iota has been reset)
        b = 1 << iota  // b == 2
        c = 1 << iota  // c == 4
)

const (
        u         = iota * 42  // u == 0     (untyped integer constant)
        v float64 = iota * 42  // v == 42.0  (float64 constant)
        w         = iota * 42  // w == 84    (untyped integer constant)
)

const x = iota  // x == 0 (iota has been reset)
const y = iota  // y == 0 (iota has been reset)

Within an ExpressionList, the value of each iota is the same because it is only incremented after each ConstSpec:

const (
        bit0, mask0 = 1 << iota, 1<<iota - 1  // bit0 == 1, mask0 == 0
        bit1, mask1                           // bit1 == 2, mask1 == 1
        _, _                                  // skips iota == 2
        bit3, mask3                           // bit3 == 8, mask3 == 7
)

This last example exploits the implicit repetition of the last non-empty expression list.


So your code might be like

const (
        A = iota
        C
        T
        G
)

or

type Base int

const (
        A Base = iota
        C
        T
        G
)

if you want bases to be a separate type from int.

Adding a custom header to HTTP request using angular.js

my suggestion will be add a function call settings like this inside the function check the header which is appropriate for it. I am sure it will definitely work. it is perfectly working for me.

function getSettings(requestData) {
    return {
        url: requestData.url,
        dataType: requestData.dataType || "json",
        data: requestData.data || {},
        headers: requestData.headers || {
            "accept": "application/json; charset=utf-8",
            'Authorization': 'Bearer ' + requestData.token
        },
        async: requestData.async || "false",
        cache: requestData.cache || "false",
        success: requestData.success || {},
        error: requestData.error || {},
        complete: requestData.complete || {},
        fail: requestData.fail || {}
    };
}

then call your data like this

    var requestData = {
        url: 'API end point',
        data: Your Request Data,
        token: Your Token
    };

    var settings = getSettings(requestData);
    settings.method = "POST"; //("Your request type")
    return $http(settings);

linq where list contains any in list

Or like this

class Movie
{
  public string FilmName { get; set; }
  public string Genre { get; set; }
}

...

var listofGenres = new List<string> { "action", "comedy" };

var Movies = new List<Movie> {new Movie {Genre="action", FilmName="Film1"},
                new Movie {Genre="comedy", FilmName="Film2"},
                new Movie {Genre="comedy", FilmName="Film3"},
                new Movie {Genre="tragedy", FilmName="Film4"}};

var movies = Movies.Join(listofGenres, x => x.Genre, y => y, (x, y) => x).ToList();

Select distinct using linq

myList.GroupBy(test => test.id)
      .Select(grp => grp.First());

Edit: as getting this IEnumerable<> into a List<> seems to be a mystery to many people, you can simply write:

var result = myList.GroupBy(test => test.id)
                   .Select(grp => grp.First())
                   .ToList();

But one is often better off working with the IEnumerable rather than IList as the Linq above is lazily evaluated: it doesn't actually do all of the work until the enumerable is iterated. When you call ToList it actually walks the entire enumerable forcing all of the work to be done up front. (And may take a little while if your enumerable is infinitely long.)

The flipside to this advice is that each time you enumerate such an IEnumerable the work to evaluate it has to be done afresh. So you need to decide for each case whether it is better to work with the lazily evaluated IEnumerable or to realize it into a List, Set, Dictionary or whatnot.

Ping site and return result in PHP

With the following function you are just sending the pure ICMP packets using socket_create. I got the following code from a user note there. N.B. You must run the following as root.

Although you can't put this in a standard web page you can run it as a cron job and populate a database with the results.

So it's best suited if you need to monitor a site.

function twitterIsUp() {
    return ping('twitter.com');
}

function ping ($host, $timeout = 1) {
    /* ICMP ping packet with a pre-calculated checksum */
    $package = "\x08\x00\x7d\x4b\x00\x00\x00\x00PingHost";
    $socket = socket_create(AF_INET, SOCK_RAW, 1);
    socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array('sec' => $timeout, 'usec' => 0));
    socket_connect($socket, $host, null);

    $ts = microtime(true);
    socket_send($socket, $package, strLen($package), 0);
    if (socket_read($socket, 255)) {    
        $result = microtime(true) - $ts;
    } else {
        $result = false;
    }
    socket_close($socket);

    return $result;
}

Types in Objective-C on iOS

Note that you can also use the C99 fixed-width types perfectly well in Objective-C:

#import <stdint.h>
...
int32_t x; // guaranteed to be 32 bits on any platform

The wikipedia page has a decent description of what's available in this header if you don't have a copy of the C standard (you should, though, since Objective-C is just a tiny extension of C). You may also find the headers limits.h and inttypes.h to be useful.

android.view.InflateException: Binary XML file line #12: Error inflating class <unknown>

In case someone gets similar issues, I had such an issue while inflating the view:

View.inflate(getApplicationContext(), R.layout.my_layout, null)

fixed by replacing getApplicationContext() with this

How to check in Javascript if one element is contained within another

Take a look at Node#compareDocumentPosition.

function isDescendant(ancestor,descendant){
    return ancestor.compareDocumentPosition(descendant) & 
        Node.DOCUMENT_POSITION_CONTAINS;
}

function isAncestor(descendant,ancestor){
    return descendant.compareDocumentPosition(ancestor) & 
        Node.DOCUMENT_POSITION_CONTAINED_BY;
}

Other relationships include DOCUMENT_POSITION_DISCONNECTED, DOCUMENT_POSITION_PRECEDING, and DOCUMENT_POSITION_FOLLOWING.

Not supported in IE<=8.

JavaScript open in a new window, not tab

For me the solution was to have

"location=0"

in the 3rd parameter. Tested on latest FF/Chrome and an old version of IE11

Full method call I use is below (As I like to use a variable width):

window.open(url, "window" + id, 'toolbar=0,location=0,scrollbars=1,statusbar=1,menubar=0,resizable=1,width=' + width + ',height=800,left=100,top=50');

Custom "confirm" dialog in JavaScript?

One other way would be using colorbox

function createConfirm(message, okHandler) {
    var confirm = '<p id="confirmMessage">'+message+'</p><div class="clearfix dropbig">'+
            '<input type="button" id="confirmYes" class="alignleft ui-button ui-widget ui-state-default" value="Yes" />' +
            '<input type="button" id="confirmNo" class="ui-button ui-widget ui-state-default" value="No" /></div>';

    $.fn.colorbox({html:confirm, 
        onComplete: function(){
            $("#confirmYes").click(function(){
                okHandler();
                $.fn.colorbox.close();
            });
            $("#confirmNo").click(function(){
                $.fn.colorbox.close();
            });
    }});
}

How to remove package using Angular CLI?

npm uninstal @angular/material

and also clear file custom-theme.scss

How to transform numpy.matrix or array to scipy sparse matrix

You can pass a numpy array or matrix as an argument when initializing a sparse matrix. For a CSR matrix, for example, you can do the following.

>>> import numpy as np
>>> from scipy import sparse
>>> A = np.array([[1,2,0],[0,0,3],[1,0,4]])
>>> B = np.matrix([[1,2,0],[0,0,3],[1,0,4]])

>>> A
array([[1, 2, 0],
       [0, 0, 3],
       [1, 0, 4]])

>>> sA = sparse.csr_matrix(A)   # Here's the initialization of the sparse matrix.
>>> sB = sparse.csr_matrix(B)

>>> sA
<3x3 sparse matrix of type '<type 'numpy.int32'>'
        with 5 stored elements in Compressed Sparse Row format>

>>> print sA
  (0, 0)        1
  (0, 1)        2
  (1, 2)        3
  (2, 0)        1
  (2, 2)        4

Using CSS td width absolute, position

Try to use

table {
  table-layout: auto;
}

If you use Bootstrap, class table has table-layout: fixed; by default.

How to pass variables from one php page to another without form?

You can pass via GET. So if you want to pass the value foobar from PageA.php to PageB.php, call it as PageB.php?value=foobar.

In PageB.php, you can access it this way:

$value = $_GET['value'];

Setting selection to Nothing when programming Excel

I do not think that this can be done. Here is some code copied with no modifications from Chip Pearson's site: http://www.cpearson.com/excel/UnSelect.aspx.

UnSelectActiveCell

This procedure will remove the Active Cell from the Selection.

Sub UnSelectActiveCell()
    Dim R As Range
    Dim RR As Range
    For Each R In Selection.Cells
        If StrComp(R.Address, ActiveCell.Address, vbBinaryCompare) <> 0 Then
            If RR Is Nothing Then
                Set RR = R
            Else
                Set RR = Application.Union(RR, R)
            End If
        End If
    Next R
    If Not RR Is Nothing Then
        RR.Select
    End If
End Sub

UnSelectCurrentArea

This procedure will remove the Area containing the Active Cell from the Selection.

Sub UnSelectCurrentArea()
    Dim Area As Range
    Dim RR As Range

    For Each Area In Selection.Areas
        If Application.Intersect(Area, ActiveCell) Is Nothing Then
            If RR Is Nothing Then
                Set RR = Area
            Else
                Set RR = Application.Union(RR, Area)
            End If
        End If
    Next Area
    If Not RR Is Nothing Then
        RR.Select
    End If
End Sub

Intercept and override HTTP requests from WebView

Here is my solution I use for my app.

I have several asset folder with css / js / img anf font files.

The application gets all filenames and looks if a file with this name is requested. If yes, it loads it from asset folder.

//get list of files of specific asset folder
        private ArrayList listAssetFiles(String path) {

            List myArrayList = new ArrayList();
            String [] list;
            try {
                list = getAssets().list(path);
                for(String f1 : list){
                    myArrayList.add(f1);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            return (ArrayList) myArrayList;
        }

        //get mime type by url
        public String getMimeType(String url) {
            String type = null;
            String extension = MimeTypeMap.getFileExtensionFromUrl(url);
            if (extension != null) {
                if (extension.equals("js")) {
                    return "text/javascript";
                }
                else if (extension.equals("woff")) {
                    return "application/font-woff";
                }
                else if (extension.equals("woff2")) {
                    return "application/font-woff2";
                }
                else if (extension.equals("ttf")) {
                    return "application/x-font-ttf";
                }
                else if (extension.equals("eot")) {
                    return "application/vnd.ms-fontobject";
                }
                else if (extension.equals("svg")) {
                    return "image/svg+xml";
                }
                type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
            }
            return type;
        }

        //return webresourceresponse
        public WebResourceResponse loadFilesFromAssetFolder (String folder, String url) {
            List myArrayList = listAssetFiles(folder);
            for (Object str : myArrayList) {
                if (url.contains((CharSequence) str)) {
                    try {
                        Log.i(TAG2, "File:" + str);
                        Log.i(TAG2, "MIME:" + getMimeType(url));
                        return new WebResourceResponse(getMimeType(url), "UTF-8", getAssets().open(String.valueOf(folder+"/" + str)));
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            return null;
        }

        //@TargetApi(Build.VERSION_CODES.LOLLIPOP)
        @SuppressLint("NewApi")
        @Override
        public WebResourceResponse shouldInterceptRequest(final WebView view, String url) {
            //Log.i(TAG2, "SHOULD OVERRIDE INIT");
            //String url = webResourceRequest.getUrl().toString();
            String extension = MimeTypeMap.getFileExtensionFromUrl(url);
            //I have some folders for files with the same extension
            if (extension.equals("css") || extension.equals("js") || extension.equals("img")) {
                return loadFilesFromAssetFolder(extension, url);
            }
            //more possible extensions for font folder
            if (extension.equals("woff") || extension.equals("woff2") || extension.equals("ttf") || extension.equals("svg") || extension.equals("eot")) {
                return loadFilesFromAssetFolder("font", url);
            }

            return null;
        }

CSS :not(:last-child):after selector

You can try this, I know is not the answers you are looking for but the concept is the same.

Where you are setting the styles for all the children and then removing it from the last child.

Code Snippet

li
  margin-right: 10px

  &:last-child
    margin-right: 0

Image

enter image description here

Atom menu is missing. How do I re-enable

CONTROL + SHIFT + P and execute command "Tree View: Show"

Can Python test the membership of multiple values in a list?

Both of the answers presented here will not handle repeated elements. For example, if you are testing whether [1,2,2] is a sublist of [1,2,3,4], both will return True. That may be what you mean to do, but I just wanted to clarify. If you want to return false for [1,2,2] in [1,2,3,4], you would need to sort both lists and check each item with a moving index on each list. Just a slightly more complicated for loop.

Days between two dates?

Do you mean full calendar days, or groups of 24 hours?

For simply 24 hours, assuming you're using Python's datetime, then the timedelta object already has a days property:

days = (a - b).days

For calendar days, you'll need to round a down to the nearest day, and b up to the nearest day, getting rid of the partial day on either side:

roundedA = a.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
roundedB = b.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
days = (roundedA - roundedB).days

Default optional parameter in Swift function

Optionals and default parameters are two different things.

An Optional is a variable that can be nil, that's it.

Default parameters use a default value when you omit that parameter, this default value is specified like this: func test(param: Int = 0)

If you specify a parameter that is an optional, you have to provide it, even if the value you want to pass is nil. If your function looks like this func test(param: Int?), you can't call it like this test(). Even though the parameter is optional, it doesn't have a default value.

You can also combine the two and have a parameter that takes an optional where nil is the default value, like this: func test(param: Int? = nil).

MySQL: @variable vs. variable. What's the difference?

MySQL has a concept of user-defined variables.

They are loosely typed variables that may be initialized somewhere in a session and keep their value until the session ends.

They are prepended with an @ sign, like this: @var

You can initialize this variable with a SET statement or inside a query:

SET @var = 1

SELECT @var2 := 2

When you develop a stored procedure in MySQL, you can pass the input parameters and declare the local variables:

DELIMITER //

CREATE PROCEDURE prc_test (var INT)
BEGIN
    DECLARE  var2 INT;
    SET var2 = 1;
    SELECT  var2;
END;
//

DELIMITER ;

These variables are not prepended with any prefixes.

The difference between a procedure variable and a session-specific user-defined variable is that a procedure variable is reinitialized to NULL each time the procedure is called, while the session-specific variable is not:

CREATE PROCEDURE prc_test ()
BEGIN
    DECLARE var2 INT DEFAULT 1;
    SET var2 = var2 + 1;
    SET @var2 = @var2 + 1;
    SELECT  var2, @var2;
END;

SET @var2 = 1;

CALL prc_test();

var2  @var2
---   ---
2     2


CALL prc_test();

var2  @var2
---   ---
2     3


CALL prc_test();

var2  @var2
---   ---
2     4

As you can see, var2 (procedure variable) is reinitialized each time the procedure is called, while @var2 (session-specific variable) is not.

(In addition to user-defined variables, MySQL also has some predefined "system variables", which may be "global variables" such as @@global.port or "session variables" such as @@session.sql_mode; these "session variables" are unrelated to session-specific user-defined variables.)

When to use Hadoop, HBase, Hive and Pig?

MapReduce is just a computing framework. HBase has nothing to do with it. That said, you can efficiently put or fetch data to/from HBase by writing MapReduce jobs. Alternatively you can write sequential programs using other HBase APIs, such as Java, to put or fetch the data. But we use Hadoop, HBase etc to deal with gigantic amounts of data, so that doesn't make much sense. Using normal sequential programs would be highly inefficient when your data is too huge.

Coming back to the first part of your question, Hadoop is basically 2 things: a Distributed FileSystem (HDFS) + a Computation or Processing framework (MapReduce). Like all other FS, HDFS also provides us storage, but in a fault tolerant manner with high throughput and lower risk of data loss (because of the replication). But, being a FS, HDFS lacks random read and write access. This is where HBase comes into picture. It's a distributed, scalable, big data store, modelled after Google's BigTable. It stores data as key/value pairs.

Coming to Hive. It provides us data warehousing facilities on top of an existing Hadoop cluster. Along with that it provides an SQL like interface which makes your work easier, in case you are coming from an SQL background. You can create tables in Hive and store data there. Along with that you can even map your existing HBase tables to Hive and operate on them.

While Pig is basically a dataflow language that allows us to process enormous amounts of data very easily and quickly. Pig basically has 2 parts: the Pig Interpreter and the language, PigLatin. You write Pig script in PigLatin and using Pig interpreter process them. Pig makes our life a lot easier, otherwise writing MapReduce is always not easy. In fact in some cases it can really become a pain.

I had written an article on a short comparison of different tools of the Hadoop ecosystem some time ago. It's not an in depth comparison, but a short intro to each of these tools which can help you to get started. (Just to add on to my answer. No self promotion intended)

Both Hive and Pig queries get converted into MapReduce jobs under the hood.

HTH

How to show current time in JavaScript in the format HH:MM:SS?

new Date().toTimeString().slice(0,8)

Note that toLocaleTimeString() might return something like 9:00:00 AM.

How to see an HTML page on Github as a normal rendered HTML page to see preview in browser, without downloading?

It's really easy to do with github pages, it's just a bit weird the first time you do it. Sorta like the first time you had to juggle 3 kittens while learning to knit. (OK, it's not all that bad)

You need a gh-pages branch:

Basically github.com looks for a gh-pages branch of the repository. It will serve all HTML pages it finds in here as normal HTML directly to the browser.

How do I get this gh-pages branch?

Easy. Just create a branch of your github repo called gh-pages. Specify --orphan when you create this branch, as you don't actually want to merge this branch back into your github branch, you just want a branch that contains your HTML resources.

$ git checkout --orphan gh-pages

What about all the other gunk in my repo, how does that fit in to it?

Nah, you can just go ahead and delete it. And it's safe to do now, because you've been paying attention and created an orphan branch which can't be merged back into your main branch and remove all your code.

I've created the branch, now what?

You need to push this branch up to github.com, so that their automation can kick in and start hosting these pages for you.

git push -u origin gh-pages

But.. My HTML is still not being served!

It takes a few minutes for github to index these branches and fire up the required infrastructure to serve up the content. Up to 10 minutes according to github.

The steps layed out by github.com

https://help.github.com/articles/creating-project-pages-manually

How do I fix certificate errors when running wget on an HTTPS URL in Cygwin?

May be this will help:

wget --no-check-certificate https://blah-blah.tld/path/filename

How to run python script on terminal (ubuntu)?

First create the file you want, with any editor like vi r gedit. And save with. Py extension.In that the first line should be

!/usr/bin/env python

Python math module

import math as m
a=int(input("Enter the no"))
print(m.sqrt(a))

from math import sqrt
print(sqrt(25))

from math import sqrt as s
print(s(25))

from math import *
print(sqrt(25))

All works.

How to add a named sheet at the end of all Excel sheets?

Try this:

Public Enum iSide
iBefore
iAfter
End Enum
Private Function addSheet(ByRef inWB As Workbook, ByVal inBeforeOrAfter As iSide, ByRef inNamePrefix As String, ByVal inName As String) As Worksheet
    On Error GoTo the_dark

    Dim wsSheet As Worksheet
    Dim bFoundWS As Boolean
    bFoundWS = False
    If inNamePrefix <> "" Then
        Set wsSheet = findWS(inWB, inNamePrefix, bFoundWS)
    End If

    If inBeforeOrAfter = iAfter Then
        If wsSheet Is Nothing Or bFoundWS = False Then
            Worksheets.Add(After:=Worksheets(Worksheets.Count)).Name = inName
        Else
            Worksheets.Add(After:=wsSheet).Name = inName
        End If
    Else
        If wsSheet Is Nothing Or bFoundWS = False Then
            Worksheets.Add(Before:=Worksheets(1)).Name = inName
        Else
            Worksheets.Add(Before:=wsSheet).Name = inName
        End If
    End If

    Set addSheet = findWS(inWB, inName, bFoundWS)         ' just to confirm it exists and gets it handle

    the_light:
    Exit Function
    the_dark:
    MsgBox "addSheet: " & inName & ": " & Err.Description, vbOKOnly, "unexpected error"
    Err.Clear
    GoTo the_light
End Function

Bootstrap: Collapse other sections when one is expanded

If you stick to HTML structure and proper selectors according to the Bootstrap convention, you should be alright.

<div class="panel-group" id="accordion">
    <div class="panel panel-default">
      <div class="panel-heading">
        <h4 class="panel-title">
          <a data-toggle="collapse" data-parent="#accordion" href="#collapse1">Collapsible Group 1</a>
        </h4>
      </div>
      <div id="collapse1" class="panel-collapse collapse in">
        <div class="panel-body">Lorem ipsum dolor sit amet, consectetur adipisicing elit,
        sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
        quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</div>
      </div>
    </div>
    <div class="panel panel-default">
      <div class="panel-heading">
        <h4 class="panel-title">
          <a data-toggle="collapse" data-parent="#accordion" href="#collapse2">Collapsible Group 2</a>
        </h4>
      </div>
      <div id="collapse2" class="panel-collapse collapse">
        <div class="panel-body">Lorem ipsum dolor sit amet, consectetur adipisicing elit,
        sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
        quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</div>
      </div>
    </div>
    <div class="panel panel-default">
      <div class="panel-heading">
        <h4 class="panel-title">
          <a data-toggle="collapse" data-parent="#accordion" href="#collapse3">Collapsible Group 3</a>
        </h4>
      </div>
      <div id="collapse3" class="panel-collapse collapse">
        <div class="panel-body">Lorem ipsum dolor sit amet, consectetur adipisicing elit,
        sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
        quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</div>
      </div>
    </div>
</div> 

DEMO

Expanding a parent <div> to the height of its children

For those who can not figure out this in instructions from this answer there:

Try to set padding value more then 0, if child divs have margin-top or margin-bottom you can replace it with padding

For example if you have

#childRightCol
{
    margin-top: 30px;
}
#childLeftCol
{
    margin-bottom: 20px;
}

it'll be better to replace it with:

#parent
{
    padding: 30px 0px 20px 0px;
}

How to remove all null elements from a ArrayList or String Array?

Using Java 8 this can be performed in various ways using streams, parallel streams and removeIf method:

List<String> stringList = new ArrayList<>(Arrays.asList(null, "A", "B", null, "C", null));
List<String> listWithoutNulls1 = stringList.stream()
                .filter(Objects::nonNull)
                .collect(Collectors.toList()); //[A,B,C]
List<String> listWithoutNulls2 = stringList.parallelStream()
                .filter(Objects::nonNull)
                .collect(Collectors.toList()); //[A,B,C]
stringList.removeIf(Objects::isNull); //[A,B,C]

The parallel stream will make use of available processors and will speed up the process for reasonable sized lists. It is always advisable to benchmark before using streams.

What is the best way to merge mp3 files?

What I really wanted was a GUI to reorder them and output them as one file

Playlist Producer does exactly that, decoding and reencoding them into a combined MP3. It's designed for creating mix tapes or simple podcasts, but you might find it useful.

(Disclosure: I wrote the software, and I profit if you buy the Pro Edition. The Lite edition is a free version with a few limitations).

Add text at the end of each line

If you'd like to add text at the end of each line in-place (in the same file), you can use -i parameter, for example:

sed -i'.bak' 's/$/:80/' foo.txt

However -i option is non-standard Unix extension and may not be available on all operating systems.

So you can consider using ex (which is equivalent to vi -e/vim -e):

ex +"%s/$/:80/g" -cwq foo.txt

which will add :80 to each line, but sometimes it can append it to blank lines.

So better method is to check if the line actually contain any number, and then append it, for example:

ex  +"g/[0-9]/s/$/:80/g" -cwq foo.txt

If the file has more complex format, consider using proper regex, instead of [0-9].

Environment Specific application.properties file in Spring Boot application

My Point , IN this arent way asking developer to create all environment related in single go, resulting in risk of exposing Production Configuration to end developer

as per 12-Factor, shouldnt be enviornment specific reside in Enviornment only .

How do we do for CI CD

  • Build Spring one time and promote to aother environment, in that case, if we have spring jar has all environment, it iwll security risk, having all environment variable in GIT

Remove quotes from String in Python

The easiest way is:

s = '"sajdkasjdsaasdasdasds"' 
import json
s = json.loads(s)

Take n rows from a spark dataframe and pass to toPandas()

You can use the limit(n) function:

l = [('Alice', 1),('Jim',2),('Sandra',3)]
df = sqlContext.createDataFrame(l, ['name', 'age'])
df.limit(2).withColumn('age2', df.age + 2).toPandas()

Or:

l = [('Alice', 1),('Jim',2),('Sandra',3)]
df = sqlContext.createDataFrame(l, ['name', 'age'])
df.withColumn('age2', df.age + 2).limit(2).toPandas()

location.host vs location.hostname and cross-browser compatibility?

MDN: https://developer.mozilla.org/en/DOM/window.location

It seems that you will get the same result for both, but hostname contains clear host name without brackets or port number.

How to set the From email address for mailx command?

You can use the "-r" option to set the sender address:

mailx -r [email protected] -s ...

Daemon not running. Starting it now on port 5037

Reference link: http://www.programering.com/a/MTNyUDMwATA.html

Steps I followed 1) Execute the command adb nodaemon server in command prompt Output at command prompt will be: The following error occurred cannot bind 'tcp:5037' The original ADB server port binding failed

2) Enter the following command query which using port 5037 netstat -ano | findstr "5037" The following information will be prompted on command prompt: TCP 127.0.0.1:5037 0.0.0.0:0 LISTENING 9288

3) View the task manager, close all adb.exe

4) Restart eclipse or other IDE

The above steps worked for me.

Origin http://localhost is not allowed by Access-Control-Allow-Origin

I fixed this (for development) with a simple nginx proxy...

# /etc/nginx/sites-enabled/default
server {
  listen 80;
  root /path/to/Development/dir;
  index index.html;

  # from your example
  location /search {
    proxy_pass http://api.master18.tiket.com;
  }
}

How to get week number of the month from the date in sql server 2008

Code is below:

set datefirst 7
declare @dt datetime='29/04/2016 00:00:00'
select (day(@dt)+datepart(WEEKDAY,dateadd(d,-day(@dt),@dt+1)))/7

Foreach value from POST from form

First, please do not use extract(), it can be a security problem because it is easy to manipulate POST parameters

In addition, you don't have to use variable variable names (that sounds odd), instead:

foreach($_POST as $key => $value) {
  echo "POST parameter '$key' has '$value'";
}

To ensure that you have only parameters beginning with 'item_name' you can check it like so:

$param_name = 'item_name';
if(substr($key, 0, strlen($param_name)) == $param_name) {
  // do something
}

Get div tag scroll position using JavaScript

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script type="text/javascript">
        function scollPos() {
            var div = document.getElementById("myDiv").scrollTop;
            document.getElementById("pos").innerHTML = div;
        }
    </script>
</head>
<body>
    <form id="form1">
    <div id="pos">
    </div>
    <div id="myDiv" style="overflow: auto; height: 200px; width: 200px;" onscroll="scollPos();">
        Place some large content here
    </div>
    </form>
</body>
</html>

View list of all JavaScript variables in Google Chrome Console

Is this the kind of output you're looking for?

for(var b in window) { 
  if(window.hasOwnProperty(b)) console.log(b); 
}

This will list everything available on the window object (all the functions and variables, e.g., $ and jQuery on this page, etc.). Though, this is quite a list; not sure how helpful it is...

Otherwise just do window and start going down its tree:

window

This will give you DOMWindow, an expandable/explorable object.

MSIE and addEventListener Problem in Javascript?

As PPK points out here, in IE you can also use

e.cancelBubble = true;

Date query with ISODate in mongodb doesn't seem to work

In the MongoDB shell:

db.getCollection('sensorevents').find({from:{$gt: new ISODate('2015-08-30 16:50:24.481Z')}})

In my nodeJS code ( using Mongoose )

    SensorEvent.Model.find( {
        from: { $gt: new Date( SensorEventListener.lastSeenSensorFrom ) }
    } )

I am querying my sensor events collection to return values where the 'from' field is greater than the given date

How to globally replace a forward slash in a JavaScript string?

You need to wrap the forward slash to avoid cross browser issues or //commenting out.

str = 'this/that and/if';

var newstr = str.replace(/[/]/g, 'ForwardSlash');

phpMyAdmin + CentOS 6.0 - Forbidden

None of the configuration above worked for me on my CentOS 7 server. After hours of searching, that's what worked for me:

Edit file phpMyAdmin.conf

sudo nano /etc/httpd/conf.d/phpMyAdmin.conf

And replace this at the top:

<Directory /usr/share/phpMyAdmin/>
   AddDefaultCharset UTF-8

   <IfModule mod_authz_core.c>
     # Apache 2.4
     <RequireAny>
       #Require ip 127.0.0.1
       #Require ip ::1
       Require all granted
     </RequireAny>
   </IfModule>
   <IfModule !mod_authz_core.c>
     # Apache 2.2
     Order Deny,Allow
     Deny from All
     Allow from 127.0.0.1
     Allow from ::1
   </IfModule>
</Directory>

how to download file in react js

browsers are smart enough to detect the link and downloading it directly when clicking on an anchor tag without using the download attribute.

after getting your file link from the api, just use plain javascript by creating anchor tag and delete it after clicking on it dynamically immediately on the fly.

const link = document.createElement('a');
link.href = `your_link.pdf`;
document.body.appendChild(link);
link.click();
document.body.removeChild(link);

Change the location of the ~ directory in a Windows install of Git Bash

I faced exactly the same issue. My home drive mapped to a network drive. Also

  1. No Write access to home drive
  2. No write access to Git bash profile
  3. No admin rights to change environment variables from control panel.

However below worked from command line and I was able to add HOME to environment variables.

rundll32 sysdm.cpl,EditEnvironmentVariables

How to add a search box with icon to the navbar in Bootstrap 3?

This one I implemented for my website , If some one got more no's of menu item and longer search bar can use this

enter image description here

enter image description here

Here is the code

       <style>
        .navbar-inverse .navbar-nav > li > a {
            color: white !important;
        }

            .navbar-inverse .navbar-nav > li > a:hover {
                text-decoration: underline;
            }

        .navbar-collapse ul li {
            padding-top: 0px;
            padding-bottom: 0px;
        }

            .navbar-collapse ul li a {
                padding-top: 0px;
                padding-bottom: 0px;
            }

        .navbar-brand img {
            width: 200px;
            height: 40px;
        }

        .navbar-inverse {
            background-color: #3A1B37;
        }
    </style>
   <div class="navbar navbar-inverse navbar-fixed-top">
        <div class="container">
            <div class="navbar-header">
                <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                </button>
                <a class="navbar-brand" runat="server" href="~/">
                    <img src="http://placehold.it/200x40/3A1B37/ffffff/?text=Apllicatin"></a>
                <div class="col-md-6 col-sm-8 col-xs-11 navbar-left">
                    <div class="navbar-form " role="search">
                        <div class="input-group">
                            <input type="text" class="form-control" placeholder="Search" name="srch-term" id="srch-term" style="max-width: 100%; width: 100%;">
                            <div class="input-group-btn">
                                <button class="btn btn-default" style="background: rgb(72, 166, 72);" type="submit"><i class="glyphicon glyphicon-search"></i></button>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
            <div class="navbar-collapse collapse">
                <ul class="nav navbar-nav">
                    <li class="navbar-brand  visible-md visible-lg visible-sm" style="visibility: hidden;" runat="server">
                        <img src="http://placehold.it/200x40/3A1B37/ffffff/?text=Apllicatin" />
                    </li>
                    <li><a runat="server" href="~/">Home</a></li>
                    <li><a runat="server" href="~/About">About</a></li>
                    <li><a runat="server" href="~/Contact">Contact</a></li>
                    <li><a runat="server" href="~/">Somthing</a></li>
                    <li><a runat="server" href="~/">Somthing</a></li>
                </ul>
                <ul class="nav navbar-nav navbar-right">
                    <li><a runat="server" href="~/Account/Register">Register</a></li>
                    <li><a runat="server" href="~/Account/Login">Log in</a></li>
                </ul> </div>

        </div>
    </div>

Drop default constraint on a column in TSQL

I would like to refer a previous question, Because I have faced same problem and solved by this solution. First of all a constraint is always built with a Hash value in it's name. So problem is this HASH is varies in different Machine or Database. For example DF__Companies__IsGlo__6AB17FE4 here 6AB17FE4 is the hash value(8 bit). So I am referring a single script which will be fruitful to all

DECLARE @Command NVARCHAR(MAX)
     declare @table_name nvarchar(256)
     declare @col_name nvarchar(256)
     set @table_name = N'ProcedureAlerts'
     set @col_name = N'EmailSent'

     select @Command ='Alter Table dbo.ProcedureAlerts Drop Constraint [' + ( select d.name
     from 
         sys.tables t
         join sys.default_constraints d on d.parent_object_id = t.object_id
         join sys.columns c on c.object_id = t.object_id
                               and c.column_id = d.parent_column_id
     where 
         t.name = @table_name
         and c.name = @col_name) + ']'

    --print @Command
    exec sp_executesql @Command

It will drop your default constraint. However if you want to create it again you can simply try this

ALTER TABLE [dbo].[ProcedureAlerts] ADD DEFAULT((0)) FOR [EmailSent]

Finally, just simply run a DROP command to drop the column.

Got a NumberFormatException while trying to parse a text file for objects

NumberFormatException invoke when you ll try to convert inavlid String for eg:"abc" value to integer..

this is valid string is eg"123". in your case split by space..

split(" "); will split line by " " by space..

How to convert JTextField to String and String to JTextField?

how to convert JTextField to string and string to JTextField in java

If you mean how to get and set String from jTextField then you can use following methods:

String str = jTextField.getText() // get string from jtextfield

and

jTextField.setText(str)  // set string to jtextfield
//or
new JTextField(str)     // set string to jtextfield

You should check JavaDoc for JTextField

Sorted array list in Java

I had the same problem. So I took the source code of java.util.TreeMap and wrote IndexedTreeMap. It implements my own IndexedNavigableMap:

public interface IndexedNavigableMap<K, V> extends NavigableMap<K, V> {
   K exactKey(int index);
   Entry<K, V> exactEntry(int index);
   int keyIndex(K k);
}

The implementation is based on updating node weights in the red-black tree when it is changed. Weight is the number of child nodes beneath a given node, plus one - self. For example when a tree is rotated to the left:

    private void rotateLeft(Entry<K, V> p) {
    if (p != null) {
        Entry<K, V> r = p.right;

        int delta = getWeight(r.left) - getWeight(p.right);
        p.right = r.left;
        p.updateWeight(delta);

        if (r.left != null) {
            r.left.parent = p;
        }

        r.parent = p.parent;


        if (p.parent == null) {
            root = r;
        } else if (p.parent.left == p) {
            delta = getWeight(r) - getWeight(p.parent.left);
            p.parent.left = r;
            p.parent.updateWeight(delta);
        } else {
            delta = getWeight(r) - getWeight(p.parent.right);
            p.parent.right = r;
            p.parent.updateWeight(delta);
        }

        delta = getWeight(p) - getWeight(r.left);
        r.left = p;
        r.updateWeight(delta);

        p.parent = r;
    }
  }

updateWeight simply updates weights up to the root:

   void updateWeight(int delta) {
        weight += delta;
        Entry<K, V> p = parent;
        while (p != null) {
            p.weight += delta;
            p = p.parent;
        }
    }

And when we need to find the element by index here is the implementation that uses weights:

public K exactKey(int index) {
    if (index < 0 || index > size() - 1) {
        throw new ArrayIndexOutOfBoundsException();
    }
    return getExactKey(root, index);
}

private K getExactKey(Entry<K, V> e, int index) {
    if (e.left == null && index == 0) {
        return e.key;
    }
    if (e.left == null && e.right == null) {
        return e.key;
    }
    if (e.left != null && e.left.weight > index) {
        return getExactKey(e.left, index);
    }
    if (e.left != null && e.left.weight == index) {
        return e.key;
    }
    return getExactKey(e.right, index - (e.left == null ? 0 : e.left.weight) - 1);
}

Also comes in very handy finding the index of a key:

    public int keyIndex(K key) {
    if (key == null) {
        throw new NullPointerException();
    }
    Entry<K, V> e = getEntry(key);
    if (e == null) {
        throw new NullPointerException();
    }
    if (e == root) {
        return getWeight(e) - getWeight(e.right) - 1;//index to return
    }
    int index = 0;
    int cmp;
    index += getWeight(e.left);

    Entry<K, V> p = e.parent;
    // split comparator and comparable paths
    Comparator<? super K> cpr = comparator;
    if (cpr != null) {
        while (p != null) {
            cmp = cpr.compare(key, p.key);
            if (cmp > 0) {
                index += getWeight(p.left) + 1;
            }
            p = p.parent;
        }
    } else {
        Comparable<? super K> k = (Comparable<? super K>) key;
        while (p != null) {
            if (k.compareTo(p.key) > 0) {
                index += getWeight(p.left) + 1;
            }
            p = p.parent;
        }
    }
    return index;
}

You can find the result of this work at http://code.google.com/p/indexed-tree-map/

TreeSet/TreeMap (as well as their indexed counterparts from the indexed-tree-map project) do not allow duplicate keys , you can use 1 key for an array of values. If you need a SortedSet with duplicates use TreeMap with values as arrays. I would do that.

Authenticated HTTP proxy with Java

You're almost there, you just have to append:

-Dhttp.proxyUser=someUserName
-Dhttp.proxyPassword=somePassword