Programs & Examples On #Watch window

How to set initial value and auto increment in MySQL?

You could also set it in the create table statement.

`CREATE TABLE(...) AUTO_INCREMENT=1000`

See full command of running/stopped container in Docker

docker ps --no-trunc will display the full command along with the other details of the running containers.

File Not Found when running PHP with Nginx

Try another *fastcgi_param* something like

fastcgi_param SCRIPT_FILENAME /usr/share/nginx/html$fastcgi_script_name;

Limiting the output of PHP's echo to 200 characters

function TitleTextLimit($text,$limit=200){
 if(strlen($text)<=$limit){
    echo $text;
 }else{
    $text = substr($text,0,$limit) . '...';
    echo $text;
 }

How do I add an "Add to Favorites" button or link on my website?

Credit to @Gert Grenander , @Alaa.Kh , and Ross Shanon

Trying to make some order:

it all works - all but the firefox bookmarking function. for some reason the 'window.sidebar.addPanel' is not a function for the debugger, though it is working fine.

The problem is that it takes its values from the calling <a ..> tag: title as the bookmark name and href as the bookmark address. so this is my code:

javascript:

$("#bookmarkme").click(function () {
  var url = 'http://' + location.host; // i'm in a sub-page and bookmarking the home page
  var name = "Snir's Homepage";

  if (navigator.userAgent.toLowerCase().indexOf('chrome') > -1){ //chrome
    alert("In order to bookmark go to the homepage and press " 
        + (navigator.userAgent.toLowerCase().indexOf('mac') != -1 ? 
            'Command/Cmd' : 'CTRL') + "+D.")
  } 
  else if (window.sidebar) { // Mozilla Firefox Bookmark
    //important for firefox to add bookmarks - remember to check out the checkbox on the popup
    $(this).attr('rel', 'sidebar');
    //set the appropriate attributes
    $(this).attr('href', url);
    $(this).attr('title', name);

    //add bookmark:
    //  window.sidebar.addPanel(name, url, '');
    //  window.sidebar.addPanel(url, name, '');
    window.sidebar.addPanel('', '', '');
  } 
  else if (window.external) { // IE Favorite
        window.external.addFavorite(url, name);
  } 
  return;
});

html:

  <a id="bookmarkme" href="#" title="bookmark this page">Bookmark This Page</a>

In internet explorer there is a different between 'addFavorite': <a href="javascript:window.external.addFavorite('http://tiny.cc/snir','snir-site')">..</a> and 'AddFavorite': <span onclick="window.external.AddFavorite(location.href, document.title);">..</span>.

example here: http://www.yourhtmlsource.com/javascript/addtofavorites.html

Important, in chrome we can't add bookmarks using js (aspnet-i): http://www.codeproject.com/Questions/452899/How-to-add-bookmark-in-Google-Chrome-Opera-and-Saf

How can I get the content of CKEditor using JQuery?

version 4.8.0

$('textarea').data('ckeditorInstance').getData();

PostgreSQL: How to change PostgreSQL user password?

TLDR:

On many systems, a user's account often contains a period, or some sort of punction (user: john.smith, horise.johnson). IN these cases a modification will have to be made to the accepted answer above. The change requires the username to be double-quoted.

Example:

ALTER USER "username.lastname" WITH PASSWORD 'password'; 

Rational:

Postgres is quite picky on when to use a 'double quote' and when to use a 'single quote'. Typically when providing a string you would use a single quote.

boolean in an if statement

Since you already initialized clearly as bool, I think === operator is not required.

What is ROWS UNBOUNDED PRECEDING used for in Teradata?

ROWS UNBOUNDED PRECEDING is no Teradata-specific syntax, it's Standard SQL. Together with the ORDER BY it defines the window on which the result is calculated.

Logically a Windowed Aggregate Function is newly calculated for each row within the PARTITION based on all ROWS between a starting row and an ending row.

Starting and ending rows might be fixed or relative to the current row based on the following keywords:

  • CURRENT ROW, the current row
  • UNBOUNDED PRECEDING, all rows before the current row -> fixed
  • UNBOUNDED FOLLOWING, all rows after the current row -> fixed
  • x PRECEDING, x rows before the current row -> relative
  • y FOLLOWING, y rows after the current row -> relative

Possible kinds of calculation include:

  • Both starting and ending row are fixed, the window consists of all rows of a partition, e.g. a Group Sum, i.e. aggregate plus detail rows
  • One end is fixed, the other relative to current row, the number of rows increases or decreases, e.g. a Running Total, Remaining Sum
  • Starting and ending row are relative to current row, the number of rows within a window is fixed, e.g. a Moving Average over n rows

So SUM(x) OVER (ORDER BY col ROWS UNBOUNDED PRECEDING) results in a Cumulative Sum or Running Total

11 -> 11
 2 -> 11 +  2                = 13
 3 -> 13 +  3 (or 11+2+3)    = 16
44 -> 16 + 44 (or 11+2+3+44) = 60

How to backup Sql Database Programmatically in C#

you can connect to the database using SqlConnection and SqlCommand and execute the following command text for example:

BACKUP DATABASE [MyDatabase] TO  DISK = 'C:\....\MyDatabase.bak'

See here for examples.

Example: Communication between Activity and Service using Messaging

Great tutorial, fantastic presentation. Neat, simple, short and very explanatory. Although, notification.setLatestEventInfo(this, getText(R.string.service_label), text, contentIntent); method is no more. As trante stated here, good approach would be:

private static final int NOTIFICATION_ID = 45349;

private void showNotification() {
    NotificationCompat.Builder builder =
            new NotificationCompat.Builder(this)
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle("My Notification Title")
                    .setContentText("Something interesting happened");

    Intent targetIntent = new Intent(this, MainActivity.class);
    PendingIntent contentIntent = PendingIntent.getActivity(this, 0, targetIntent, PendingIntent.FLAG_UPDATE_CURRENT);
    builder.setContentIntent(contentIntent);
    _nManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    _nManager.notify(NOTIFICATION_ID, builder.build());
}

@Override
public void onDestroy() {
    super.onDestroy();
    if (_timer != null) {_timer.cancel();}
    _counter=0;
    _nManager.cancel(NOTIFICATION_ID); // Cancel the persistent notification.
    Log.i("PlaybackService", "Service Stopped.");
    _isRunning = false;
}

Checked myself, everything works like a charm (activity and service names may differ from original).

How to use a link to call JavaScript?

Unobtrusive JavaScript, no library dependency:

<html>
<head>
    <script type="text/javascript">

        // Wait for the page to load first
        window.onload = function() {

          //Get a reference to the link on the page
          // with an id of "mylink"
          var a = document.getElementById("mylink");

          //Set code to run when the link is clicked
          // by assigning a function to "onclick"
          a.onclick = function() {

            // Your code here...

            //If you don't want the link to actually 
            // redirect the browser to another page,
            // "google.com" in our example here, then
            // return false at the end of this block.
            // Note that this also prevents event bubbling,
            // which is probably what we want here, but won't 
            // always be the case.
            return false;
          }
        }
    </script>
</head>
<body>
    <a id="mylink" href="http://www.google.com">linky</a>        
</body>
</html>

How to dynamically insert a <script> tag via jQuery after page load?

Here is a much clearer way — no need for jQuery — which adds a script as the last child of <body>:

document.body.innerHTML +='<script src="mycdn.js"><\/script>'

But if you want to add and load scripts use Rocket Hazmat's method.

Function stoi not declared

stoi is a C++11 function. If you aren't using a compiler that understands C++11, this simply won't compile.

You can use a stringstream instead to read the input:

stringstream ss(hours0);
ss >> hours;

Determine which MySQL configuration file is being used

I installed mysql use brew install mysql

mysqld --verbose --help | less

And it shows:

enter image description here

How to merge rows in a column into one cell in excel?

For those who have Excel 2016 (and I suppose next versions), there is now directly the CONCAT function, which will replace the CONCATENATE function.

So the correct way to do it in Excel 2016 is :

=CONCAT(A1:A4)

which will produce :

Iamaboy

For users of olders versions of Excel, the other answers are relevant.

How to clear Route Caching on server: Laravel 5.2.37

For your case solution is :

php artisan cache:clear
php artisan route:cache

Optimizing Route Loading is a must on production :

If you are building a large application with many routes, you should make sure that you are running the route:cache Artisan command during your deployment process:

php artisan route:cache

This command reduces all of your route registrations into a single method call within a cached file, improving the performance of route registration when registering hundreds of routes.

Since this feature uses PHP serialization, you may only cache the routes for applications that exclusively use controller based routes. PHP is not able to serialize Closures.

Laravel 5 clear cache from route, view, config and all cache data from application

I would like to share my experience and solution. when i was working on my laravel e commerce website with gitlab. I was fetching one issue suddenly my view cache with error during development. i did try lot to refresh and something other but i can't see any more change in my view, but at last I did resolve my problem using laravel command so, let's see i added several command for clear cache from view, route, config etc.

Reoptimized class loader:

php artisan optimize

Clear Cache facade value:

php artisan cache:clear

Clear Route cache:

php artisan route:cache

Clear View cache:

php artisan view:clear

Clear Config cache:

php artisan config:cache

Try/catch does not seem to have an effect

If you want try/catch to work for all errors (not just the terminating errors) you can manually make all errors terminating by setting the ErrorActionPreference.

try {

   $ErrorActionPreference = "Stop"; #Make all errors terminating
   get-item filethatdoesntexist; # normally non-terminating
   write-host "You won't hit me";  
} catch{
   Write-Host "Caught the exception";
   Write-Host $Error[0].Exception;
}finally{
   $ErrorActionPreference = "Continue"; #Reset the error action pref to default
}

Alternatively... you can make your own trycatch function that accepts scriptblocks so that your try catch calls are not as kludge. I have mine return true/false just in case i need to check if there was an error... but it doesnt have to. Also, exception logging is optional, and can be taken care of in the catch, but i found myself always calling the logging function in the catch block, so i added it to the try catch function.

function log([System.String] $text){write-host $text;}

function logException{
    log "Logging current exception.";
    log $Error[0].Exception;
}


function mytrycatch ([System.Management.Automation.ScriptBlock] $try,
                    [System.Management.Automation.ScriptBlock] $catch,
                    [System.Management.Automation.ScriptBlock]  $finally = $({})){



# Make all errors terminating exceptions.
    $ErrorActionPreference = "Stop";

    # Set the trap
    trap [System.Exception]{
        # Log the exception.
        logException;

        # Execute the catch statement
        & $catch;

        # Execute the finally statement
        & $finally

        # There was an exception, return false
        return $false;
    }

    # Execute the scriptblock
    & $try;

    # Execute the finally statement
    & $finally

    # The following statement was hit.. so there were no errors with the scriptblock
    return $true;
}


#execute your own try catch
mytrycatch {
        gi filethatdoesnotexist; #normally non-terminating
        write-host "You won't hit me."
    } {
        Write-Host "Caught the exception";
    }

Android view pager with page indicator

You Can create a Linear layout containing an array of TextView (mDots). To represent the textView as Dots provide this HTML source in your code . refer my code . I got this information from Youtube Channel TVAC Studio . here the code : `

    addDotsIndicator(0);
    viewPager.addOnPageChangeListener(viewListener);
}

public void addDotsIndicator(int position)
{
        mDots = new TextView[5];
        mDotLayout.removeAllViews();

        for (int i = 0; i<mDots.length ; i++)
        {
             mDots[i]=new TextView(this);
             mDots[i].setText(Html.fromHtml("&#8226;"));            //HTML for dots
             mDots[i].setTextSize(35);
             mDots[i].setTextColor(getResources().getColor(R.color.colorAccent));

             mDotLayout.addView(mDots[i]);
        }

        if(mDots.length>0)
        {
            mDots[position].setTextColor(getResources().getColor(R.color.orange));
        }
}

ViewPager.OnPageChangeListener viewListener = new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int position, float positionOffset, int 
   positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {

        addDotsIndicator(position);
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
};`

Create a custom View by inflating a layout?

Yes you can do this. RelativeLayout, LinearLayout, etc are Views so a custom layout is a custom view. Just something to consider because if you wanted to create a custom layout you could.

What you want to do is create a Compound Control. You'll create a subclass of RelativeLayout, add all our your components in code (TextView, etc), and in your constructor you can read the attributes passed in from the XML. You can then pass that attribute to your title TextView.

http://developer.android.com/guide/topics/ui/custom-components.html

How do I write the 'cd' command in a makefile?

Like this:

target:
    $(shell cd ....); \
    # ... commands execution in this directory
    # ... no need to go back (using "cd -" or so)
    # ... next target will be automatically in prev dir

Good luck!

Among $_REQUEST, $_GET and $_POST which one is the fastest?

I only ever use _GET or _POST. I prefer to have control.

What I don't like about either code fragment in the OP is that they discard the information on which HTTP method was used. And that information is important for input sanitization.

For example, if a script accepts data from a form that's going to be entered into the DB then the form had better use POST (use GET only for idempotent actions). But if the script receives the input data via the GET method then it should (normally) be rejected. For me, such a situation might warrant writing a security violation to the error log since it's a sign somebody is trying something on.

With either code fragment in the OP, this sanitization wouldn't be possible.

java: use StringBuilder to insert at the beginning

Difference Between String, StringBuilder And StringBuffer Classes
String
String is immutable ( once created can not be changed )object. The object created as a
String is stored in the Constant String Pool.
Every immutable object in Java is thread-safe, which implies String is also thread-safe. String
can not be used by two threads simultaneously.
String once assigned can not be changed.
StringBuffer
StringBuffer is mutable means one can change the value of the object. The object created
through StringBuffer is stored in the heap. StringBuffer has the same methods as the
StringBuilder , but each method in StringBuffer is synchronized that is StringBuffer is thread
safe .
Due to this, it does not allow two threads to simultaneously access the same method. Each
method can be accessed by one thread at a time.
But being thread-safe has disadvantages too as the performance of the StringBuffer hits due
to thread-safe property. Thus StringBuilder is faster than the StringBuffer when calling the
same methods of each class.
String Buffer can be converted to the string by using
toString() method.

    StringBuffer demo1 = new StringBuffer("Hello") ;

// The above object stored in heap and its value can be changed.
/
// Above statement is right as it modifies the value which is allowed in the StringBuffer
StringBuilder
StringBuilder is the same as the StringBuffer, that is it stores the object in heap and it can also
be modified. The main difference between the StringBuffer and StringBuilder is
that StringBuilder is also not thread-safe.
StringBuilder is fast as it is not thread-safe.
/
// The above object is stored in the heap and its value can be modified
/
// Above statement is right as it modifies the value which is allowed in the StringBuilder

How to Select a substring in Oracle SQL up to a specific character?

You need to get the position of the first underscore (using INSTR) and then get the part of the string from 1st charecter to (pos-1) using substr.

  1  select 'ABC_blahblahblah' test_string,
  2         instr('ABC_blahblahblah','_',1,1) position_underscore,
  3         substr('ABC_blahblahblah',1,instr('ABC_blahblahblah','_',1,1)-1) result
  4*   from dual
SQL> /

TEST_STRING      POSITION_UNDERSCORE RES
---------------- ------------------  ---
ABC_blahblahblah                  4  ABC

Instr documentation

Susbtr Documentation

How to use DISTINCT and ORDER BY in same SELECT statement?

SELECT DISTINCT Category FROM MonitoringJob ORDER BY Category ASC

#pragma mark in Swift?

For those who are interested in using extensions vs pragma marks (as mentioned in the first comment), here is how to implement it from a Swift Engineer:

import UIKit

class SwiftTableViewController: UITableViewController {

    init(coder aDecoder: NSCoder!) {
        super.init(coder: aDecoder)

    }

    override func viewDidLoad() {
        super.viewDidLoad()

    }
}

extension SwiftTableViewController {
    override func numberOfSectionsInTableView(tableView: UITableView?) -> Int {
        return 1
    }

    override func tableView(tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
        return 5
    }

    override func tableView(tableView: UITableView?, cellForRowAtIndexPath indexPath: NSIndexPath?) -> UITableViewCell? {
        let cell = tableView?.dequeueReusableCellWithIdentifier("myCell", forIndexPath: indexPath) as UITableViewCell;

        cell.textLabel.text = "Hello World"

        return cell
    }

}

It's also not necessarily the best practice, but this is how you do it if you like.

How To Check If A Key in **kwargs Exists?

You want

if 'errormessage' in kwargs:
    print("found it")

To get the value of errormessage

if 'errormessage' in kwargs:
    print("errormessage equals " + kwargs.get("errormessage"))

In this way, kwargs is just another dict. Your first example, if kwargs['errormessage'], means "get the value associated with the key "errormessage" in kwargs, and then check its bool value". So if there's no such key, you'll get a KeyError.

Your second example, if errormessage in kwargs:, means "if kwargs contains the element named by "errormessage", and unless "errormessage" is the name of a variable, you'll get a NameError.

I should mention that dictionaries also have a method .get() which accepts a default parameter (itself defaulting to None), so that kwargs.get("errormessage") returns the value if that key exists and None otherwise (similarly kwargs.get("errormessage", 17) does what you might think it does). When you don't care about the difference between the key existing and having None as a value or the key not existing, this can be handy.

Markdown and including multiple files

Multimarkdown has this natively. It calls it file transclusion:

{{some_other_file.txt}}

is all it takes. Weird name, but ticks all the boxes.

Map with Key as String and Value as List in Groovy

Groovy accepts nearly all Java syntax, so there is a spectrum of choices, as illustrated below:

// Java syntax 

Map<String,List> map1  = new HashMap<>();
List list1 = new ArrayList();
list1.add("hello");
map1.put("abc", list1); 
assert map1.get("abc") == list1;

// slightly less Java-esque

def map2  = new HashMap<String,List>()
def list2 = new ArrayList()
list2.add("hello")
map2.put("abc", list2)
assert map2.get("abc") == list2

// typical Groovy

def map3  = [:]
def list3 = []
list3 << "hello"
map3.'abc'= list3
assert map3.'abc' == list3

How to measure time elapsed on Javascript?

var seconds = 0;
setInterval(function () {
  seconds++;
}, 1000);

There you go, now you have a variable counting seconds elapsed. Since I don't know the context, you'll have to decide whether you want to attach that variable to an object or make it global.

Set interval is simply a function that takes a function as it's first parameter and a number of milliseconds to repeat the function as it's second parameter.

You could also solve this by saving and comparing times.

EDIT: This answer will provide very inconsistent results due to things such as the event loop and the way browsers may choose to pause or delay processing when a page is in a background tab. I strongly recommend using the accepted answer.

IIS7 deployment - duplicate 'system.web.extensions/scripting/scriptResourceHandler' section

This error message seems to come up in various situations.

In my case, on top of my application's Web.Config file I had an extra Web.Config file in the root folder (C:\Inetpub\www.root). Probably left there after some testing, I had forgotten all about it, and couldn't figure out what the problem was.

Removing it solved the problem for me.

Installing a plain plugin jar in Eclipse 3.5

Since the advent of p2, you should be using the dropins directory instead.

To be completely clear create "plugins" under "/dropins" and make sure to restart eclipse with the "-clean" option.

Python: Converting from ISO-8859-1/latin1 to UTF-8

For Python 3:

bytes(apple,'iso-8859-1').decode('utf-8')

I used this for a text incorrectly encoded as iso-8859-1 (showing words like VeÅ\x99ejné) instead of utf-8. This code produces correct version Verejné.

How to prevent errno 32 broken pipe?

This might be because you are using two method for inserting data into database and this cause the site to slow down.

def add_subscriber(request, email=None):
    if request.method == 'POST':
        email = request.POST['email_field']
        e = Subscriber.objects.create(email=email).save()  <==== 
        return HttpResponseRedirect('/')
    else:
        return HttpResponseRedirect('/')

In above function, the error is where arrow is pointing. The correct implementation is below:

def add_subscriber(request, email=None):
    if request.method == 'POST':
        email = request.POST['email_field']
        e = Subscriber.objects.create(email=email)
        return HttpResponseRedirect('/')
    else:
        return HttpResponseRedirect('/')

Eclipse error "Could not find or load main class"

I ran into this error today because I set up a hello world program and then cut and pasted a new program into the same file. To fix the problem of not finding hello world as the last was called I clicked Run-> Run Configurations and then under Main Class I clicked search and it found my new class name and replaced it with the correct new name in the text that I pasted. This is a newbie problem I know but it is also easy to fix. I hope this helps someone! Douglas

C++ class forward declaration

In order for new T to compile, T must be a complete type. In your case, when you say new tile_tree_apple inside the definition of tile_tree::tick, tile_tree_apple is incomplete (it has been forward declared, but its definition is later in your file). Try moving the inline definitions of your functions to a separate source file, or at least move them after the class definitions.

Something like:

class A
{
    void f1();
    void f2();
};
class B
{
   void f3();
   void f4();
};

inline void A::f1() {...}
inline void A::f2() {...}
inline void B::f3() {...}
inline void B::f4() {...}

When you write your code this way, all references to A and B in these methods are guaranteed to refer to complete types, since there are no more forward references!

SQL-Server: Is there a SQL script that I can use to determine the progress of a SQL Server backup or restore process?

Here's a simple script that generally does the trick for me:

SELECT command, percent_complete,total_elapsed_time, estimated_completion_time, start_time
  FROM sys.dm_exec_requests
  WHERE command IN ('RESTORE DATABASE','BACKUP DATABASE') 

JPA Query selecting only specific columns without using Criteria Query?

Projections can be used to select only specific properties(columns) of an entity object.

From the docs

Spring Data Repositories usually return the domain model when using query methods. However, sometimes, you may need to alter the view of that model for various reasons. In this section, you will learn how to define projections to serve up simplified and reduced views of resources.

Define an interface with only the getters you want.

interface CustomObject {  
    String getA(); // Actual property name is A
    String getB(); // Actual property name is B 
}

Now return CustomObject from your repository like so :

public interface YOU_REPOSITORY_NAME extends JpaRepository<YOUR_ENTITY, Long> {
    CustomObject findByObjectName(String name);
}

URLEncoder not able to translate space character

Am I using the wrong method? What is the correct method I should be using?

Yes, this method java.net.URLEncoder.encode wasn't made for converting " " to "20%" according to spec (source).

The space character " " is converted into a plus sign "+".

Even this is not the correct method, you can modify this to: System.out.println(java.net.URLEncoder.encode("Hello World", "UTF-8").replaceAll("\\+", "%20"));have a nice day =).

Using :before CSS pseudo element to add image to modal

Content and before are both highly unreliable across browsers. I would suggest sticking with jQuery to accomplish this. I'm not sure what you're doing to figure out if this carrot needs to be added or not, but you should get the overall idea:

$(".Modal").before("<img src='blackCarrot.png' class='ModalCarrot' />");

How do you setLayoutParams() for an ImageView?

Old thread but I had the same problem now. If anyone encounters this he'll probably find this answer:

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(30, 30);
yourImageView.setLayoutParams(layoutParams);

This will work only if you add the ImageView as a subView to a LinearLayout. If you add it to a RelativeLayout you will need to call:

RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(30, 30);
yourImageView.setLayoutParams(layoutParams);

Put text at bottom of div

Thanks @Harry the following code works for me:

.your-div{
   vertical-align: bottom;
   display: table-cell;
}

How do I search a Perl array for a matching string?

Perl string match can also be used for a simple yes/no.

my @foo=("hello", "world", "foo", "bar");

if ("@foo" =~ /\bhello\b/){
    print "found";
}
else{
    print "not found";
}

How to find Oracle Service Name

Found here, no DBA : Checking oracle sid and database name

select * from global_name;

Remove padding from columns in Bootstrap 3

I guess it's easier to just use

margin:-30px;

to override the original value set by bootstrap.

I've tried

margin: 0px -30px 0px -30px;

and it worked for me.

How to extract table as text from the PDF using Python?

If your pdf is text-based and not a scanned document (i.e. if you can click and drag to select text in your table in a PDF viewer), then you can use the module camelot-py with

import camelot
tables = camelot.read_pdf('foo.pdf')

You then can choose how you want to save the tables (as csv, json, excel, html, sqlite), and whether the output should be compressed in a ZIP archive.

tables.export('foo.csv', f='csv', compress=False)

Edit: tabula-py appears roughly 6 times faster than camelot-py so that should be used instead.

import camelot
import cProfile
import pstats
import tabula

cmd_tabula = "tabula.read_pdf('table.pdf', pages='1', lattice=True)"
prof_tabula = cProfile.Profile().run(cmd_tabula)
time_tabula = pstats.Stats(prof_tabula).total_tt

cmd_camelot = "camelot.read_pdf('table.pdf', pages='1', flavor='lattice')"
prof_camelot = cProfile.Profile().run(cmd_camelot)
time_camelot = pstats.Stats(prof_camelot).total_tt

print(time_tabula, time_camelot, time_camelot/time_tabula)

gave

1.8495559890000015 11.057014036000016 5.978199147125147

How to create localhost database using mysql?

removing temp files, and did you restart the computer or stop the MySQL service? That's the error message you get when there isn't a MySQL server running.

How to link to a <div> on another page?

You can add hash info in next page url to move browser at specific position(any html element), after page is loaded.

This is can done in this way:

add hash in the url of next_page : example.com#hashkey

$( document ).ready(function() {

  ##get hash code at next page
  var hashcode = window.location.hash;

  ## move page to any specific position of next page(let that is div with id "hashcode")
  $('html,body').animate({scrollTop: $('div#'+hascode).offset().top},'slow');

});

Set Font Color, Font Face and Font Size in PHPExcel

I recommend you start reading the documentation (4.6.18. Formatting cells). When applying a lot of formatting it's better to use applyFromArray() According to the documentation this method is also suppose to be faster when you're setting many style properties. There's an annex where you can find all the possible keys for this function.

This will work for you:

$phpExcel = new PHPExcel();

$styleArray = array(
    'font'  => array(
        'bold'  => true,
        'color' => array('rgb' => 'FF0000'),
        'size'  => 15,
        'name'  => 'Verdana'
    ));

$phpExcel->getActiveSheet()->getCell('A1')->setValue('Some text');
$phpExcel->getActiveSheet()->getStyle('A1')->applyFromArray($styleArray);

To apply font style to complete excel document:

 $styleArray = array(
   'font'  => array(
        'bold'  => true,
        'color' => array('rgb' => 'FF0000'),
        'size'  => 15,
        'name'  => 'Verdana'
    ));      
 $phpExcel->getDefaultStyle()
    ->applyFromArray($styleArray);

animating addClass/removeClass with jQuery

Although, the question is fairly old, I'm adding info not present in other answers.

The OP is using stop() to stop the current animation as soon as the event completes. However, using the right mix of parameters with the function should help. eg. stop(true,true) or stop(true,false) as this affects the queued animations well.

The following link illustrates a demo that shows the different parameters available with stop() and how they differ from finish().

http://api.jquery.com/finish/

Although the OP had no issues using JqueryUI, this is for other users who may come across similar scenarios but cannot use JqueryUI/need to support IE7 and 8 too.

django change default runserver port

  1. Create enviroment variable in your .bashrc

    export RUNSERVER_PORT=8010

  2. Create alias

    alias runserver='django-admin runserver $RUNSERVER_PORT'

Im using zsh and virtualenvs wrapper. I put export in projects postactivate script and asign port for every project.

workon someproject
runserver

use std::fill to populate vector with increasing numbers

I've seen the answers with std::generate but you can also "improve" that by using static variables inside the lambda, instead of declaring a counter outside of the function or creating a generator class :

std::vector<int> vec;
std::generate(vec.begin(), vec.end(), [] {
    static int i = 0;
    return i++;
});

I find it a little more concise

Using custom fonts using CSS?

there's also an interesting tool called CUFON. There's a demonstration of how to use it in this blog It's really simple and interesting. Also, it doesn't allow people to ctrl+c/ctrl+v the generated content.

How to calculate the angle between a line and the horizontal axis?

I have found a solution in Python that is working well !

from math import atan2,degrees

def GetAngleOfLineBetweenTwoPoints(p1, p2):
    return degrees(atan2(p2 - p1, 1))

print GetAngleOfLineBetweenTwoPoints(1,3)

redirect to current page in ASP.Net

http://en.wikipedia.org/wiki/Post/Redirect/Get

The most common way to implement this pattern in ASP.Net is to use Response.Redirect(Request.RawUrl)

Consider the differences between Redirect and Transfer. Transfer really isn't telling the browser to forward to a clear form, it's simply returning a cleared form. That may or may not be what you want.

Response.Redirect() does not a waste round trip. If you post to a script that clears the form by Server.Transfer() and reload you will be asked to repost by most browsers since the last action was a HTTP POST. This may cause your users to unintentionally repeat some action, eg. place a second order which will have to be voided later.

QtCreator: No valid kits found

Though OP is asking about Windows, this error also occurs on Ubuntu Linux and Google lists this result first when you search for the error"QtCreator: No valid kits found".

On Ubuntu this is solved by running:

For Qt5:

sudo apt-get install qt5-default

For Qt4:

sudo apt-get install qt4-dev-tools libqt4-dev libqt4-core libqt4-gui

This question is answered here and here, though those entries are less SEO-friendly...

Should try...catch go inside or outside a loop?

Performance: as Jeffrey said in his reply, in Java it doesn't make much difference.

Generally, for readability of the code, your choice of where to catch the exception depends upon whether you want the loop to keep processing or not.

In your example you returned upon catching an exception. In that case, I'd put the try/catch around the loop. If you simply want to catch a bad value but carry on processing, put it inside.

The third way: You could always write your own static ParseFloat method and have the exception handling dealt with in that method rather than your loop. Making the exception handling isolated to the loop itself!

class Parsing
{
    public static Float MyParseFloat(string inputValue)
    {
        try
        {
            return Float.parseFloat(inputValue);
        }
        catch ( NumberFormatException e )
        {
            return null;
        }
    }

    // ....  your code
    for(int i = 0; i < max; i++) 
    {
        String myString = ...;
        Float myNum = Parsing.MyParseFloat(myString);
        if ( myNum == null ) return;
        myFloats[i] = (float) myNum;
    }
}

How to make a HTTP PUT request?


protected void UpdateButton_Click(object sender, EventArgs e)
        {
            var values = string.Format("Name={0}&Family={1}&Id={2}", NameToUpdateTextBox.Text, FamilyToUpdateTextBox.Text, IdToUpdateTextBox.Text);
            var bytes = Encoding.ASCII.GetBytes(values);
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(string.Format("http://localhost:51436/api/employees"));
            request.Method = "PUT";
            request.ContentType = "application/x-www-form-urlencoded";
            using (var requestStream = request.GetRequestStream())
            {
                requestStream.Write(bytes, 0, bytes.Length);
            }
            var response =  (HttpWebResponse) request.GetResponse();

            if (response.StatusCode == HttpStatusCode.OK)
                UpdateResponseLabel.Text = "Update completed";
            else
                UpdateResponseLabel.Text = "Error in update";
        }

Get current AUTO_INCREMENT value for any table

You can get all of the table data by using this query:

SHOW TABLE STATUS FROM `DatabaseName` WHERE `name` LIKE 'TableName' ;

You can get exactly this information by using this query:

SELECT `AUTO_INCREMENT`
FROM  INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'DatabaseName'
AND   TABLE_NAME   = 'TableName';

Disable beep of Linux Bash on Windows 10

Uncommenting set bell-style none in /etc/inputrc and creating a .bash_profile with setterm -blength 0 didn't stop vim from beeping.

What worked for me was creating a .vimrc file in my home directory with set visualbell.

Source: https://linuxconfig.org/turn-off-beep-bell-on-linux-terminal

OPTION (RECOMPILE) is Always Faster; Why?

To add to the excellent list (given by @CodeCowboyOrg) of situations where OPTION(RECOMPILE) can be very helpful,

  1. Table Variables. When you are using table variables, there will not be any pre-built statistics for the table variable, often leading to large differences between estimated and actual rows in the query plan. Using OPTION(RECOMPILE) on queries with table variables allows generation of a query plan that has a much better estimate of the row numbers involved. I had a particularly critical use of a table variable that was unusable, and which I was going to abandon, until I added OPTION(RECOMPILE). The run time went from hours to just a few minutes. That is probably unusual, but in any case, if you are using table variables and working on optimizing, it's well worth seeing whether OPTION(RECOMPILE) makes a difference.

Is there a query language for JSON?

Another way to look at this would be to use mongoDB You can store your JSON in mongo and then query it via the mongodb query syntax.

How to get Locale from its String representation in Java?

This answer may be a little late, but it turns out that parsing out the string is not as ugly as the OP assumed. I found it quite simple and concise:

public static Locale fromString(String locale) {
    String parts[] = locale.split("_", -1);
    if (parts.length == 1) return new Locale(parts[0]);
    else if (parts.length == 2
            || (parts.length == 3 && parts[2].startsWith("#")))
        return new Locale(parts[0], parts[1]);
    else return new Locale(parts[0], parts[1], parts[2]);
}

I tested this (on Java 7) with all the examples given in the Locale.toString() documentation: "en", "de_DE", "_GB", "en_US_WIN", "de__POSIX", "zh_CN_#Hans", "zh_TW_#Hant-x-java", and "th_TH_TH_#u-nu-thai".

IMPORTANT UPDATE: This is not recommended for use in Java 7+ according to the documentation:

In particular, clients who parse the output of toString into language, country, and variant fields can continue to do so (although this is strongly discouraged), although the variant field will have additional information in it if script or extensions are present.

Use Locale.forLanguageTag and Locale.toLanguageTag instead, or if you must, Locale.Builder.

How do you implement a good profanity filter?

If you can do something like Digg/Stackoverflow where the users can downvote/mark obscene content... do so.

Then all you need to do is review the "naughty" users, and block them if they break the rules.

Iterating through a list to render multiple widgets in Flutter?

Basically when you hit 'return' on a function the function will stop and will not continue your iteration, so what you need to do is put it all on a list and then add it as a children of a widget

you can do something like this:

  Widget getTextWidgets(List<String> strings)
  {
    List<Widget> list = new List<Widget>();
    for(var i = 0; i < strings.length; i++){
        list.add(new Text(strings[i]));
    }
    return new Row(children: list);
  }

or even better, you can use .map() operator and do something like this:

  Widget getTextWidgets(List<String> strings)
  {
    return new Row(children: strings.map((item) => new Text(item)).toList());
  }

Select query to get data from SQL Server

SqlCommand.ExecuteNonQuery Method

You can use the ExecuteNonQuery to perform catalog operations (for example, querying the structure of a database or creating database objects such as tables), or to change the data in a database without using a DataSet by executing UPDATE, INSERT, or DELETE statements. Although the ExecuteNonQuery returns no rows, any output parameters or return values mapped to parameters are populated with data. For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. When a trigger exists on a table being inserted or updated, the return value includes the number of rows affected by both the insert or update operation and the number of rows affected by the trigger or triggers. For all other types of statements, the return value is -1. If a rollback occurs, the return value is also -1.

SqlCommand.ExecuteScalar Method Executes a Transact-SQL statement against the connection and returns the number of rows affected.

So to get no. of statements returned by SELECT statement you have to use ExecuteScalar method.

Reference: http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.executenonquery(v=vs.110).aspx

So try below code:

SqlConnection conn = new SqlConnection("Data Source=;Initial Catalog=;Persist Security Info=True;User ID=;Password=");
conn.Open();

SqlCommand command = new SqlCommand("Select id from [table1] where name=@zip", conn);
command.Parameters.AddWithValue("@zip","india");
 // int result = command.ExecuteNonQuery();
using (SqlDataReader reader = command.ExecuteReader())
{
  if (reader.Read())
  {
     Console.WriteLine(String.Format("{0}",reader["id"]));
   }
}

conn.Close();

The project cannot be built until the build path errors are resolved.

This happens when libraries added to the project doesn't have the correct path.

  1. Right click on your project (from package explorer)
  2. Got build path -> configure build path
  3. Select the libraries tab
  4. Fix the path error (give the correct path) by editing jars or classes at fault

Calculating average of an array list?

Use a double for the sum, otherwise you are doing an integer division and you won't get any decimals:

private double calculateAverage(List <Integer> marks) {
    if (marks == null || marks.isEmpty()) {
        return 0;
    }

    double sum = 0;
    for (Integer mark : marks) {
        sum += mark;
    }

    return sum / marks.size();
}

or using the Java 8 stream API:

    return marks.stream().mapToInt(i -> i).average().orElse(0);

How do I ignore files in Subversion?

SVN ignore is easy to manage in TortoiseSVN. Open TortoiseSVN and right-click on file menu then select Add to ignore list.

This will add the files in the svn:ignore property. When we checking in the files then those file which is matched with svn:ignore that will be ignored and will not commit.

In Visual Studio project we have added following files to ignore:

bin obj
*.exe
*.dll
*.pdb
*.suo

We are managing source code on SVN of Comparetrap using this method successfully

Returning JSON object from an ASP.NET page

no problem doing it with asp.... it's most natural to do so with MVC, but can be done with standard asp as well.

The MVC framework has all sorts of helper classes for JSON, if you can, I'd suggest sussing in some MVC-love, if not, you can probably easily just get the JSON helper classes used by MVC in and use them in the context of asp.net.

edit:

here's an example of how to return JSON data with MVC. This would be in your controller class. This is out of the box functionality with MVC--when you crate a new MVC project this stuff gets auto-created so it's nothing special. The only thing that I"m doing is returning an actionResult that is JSON. The JSON method I'm calling is a method on the Controller class. This is all very basic, default MVC stuff:

public ActionResult GetData()
{
    var data = new { Name="kevin", Age=40 };
    return Json(data, JsonRequestBehavior.AllowGet);
}

This return data could be called via JQuery as an ajax call thusly:

$.get("/Reader/GetData/", function(data) { someJavacriptMethodOnData(data); });

CSS values using HTML5 data attribute

You can create with javascript some css-rules, which you can later use in your styles: http://jsfiddle.net/ARTsinn/vKbda/

var addRule = (function (sheet) {
    if(!sheet) return;
    return function (selector, styles) {
        if (sheet.insertRule) return sheet.insertRule(selector + " {" + styles + "}", sheet.cssRules.length);
        if (sheet.addRule) return sheet.addRule(selector, styles);
    }
}(document.styleSheets[document.styleSheets.length - 1]));

var i = 101;
while (i--) {
    addRule("[data-width='" + i + "%']", "width:" + i + "%");
}

This creates 100 pseudo-selectors like this:

[data-width='1%'] { width: 1%; }
[data-width='2%'] { width: 2%; }
[data-width='3%'] { width: 3%; }
...
[data-width='100%'] { width: 100%; }

Note: This is a bit offtopic, and not really what you (or someone) wants, but maybe helpful.

Changing element style attribute dynamically using JavaScript

It's almost correct.

Since the - is a javascript operator, you can't really have that in property names. If you were setting, border or something single-worded like that instead, your code would work just fine.

However, the thing you need to remember for padding-top, and for any hyphenated attribute name, is that in javascript, you remove the hyphen, and make the next letter uppercase, so in your case that'd be paddingTop.

There are some other exceptions. JavaScript has some reserved words, so you can't set float like that, for instance. Instead, in some browsers you need to use cssFloat and in others styleFloat. It is for discrepancies like this that it is recommended that you use a framework such as jQuery, that handles browser incompatibilities for you...

Split string into strings by length?

  • :param s: str; source string
  • :param w: int; width to split on

Using the textwrap module:

PyDocs-textwrap

import textwrap
def wrap(s, w):
    return textwrap.fill(s, w)

:return str:

Inspired by Alexander's Answer

PyDocs-data structures

def wrap(s, w):
    return [s[i:i + w] for i in range(0, len(s), w)]
  • :return list:

Inspired by Eric's answer

PyDocs-regex

import re
def wrap(s, w):    
    sre = re.compile(rf'(.{{{w}}})')
    return [x for x in re.split(sre, s) if x]
  • :return list:

Complete Code Examples/Alternative Methods

How to import an existing directory into Eclipse?

These days, there's a better solution for importing an existing PHP project. The PDT plugin now has an option on the New PHP Project dialog just for this. So:

From File->New->PHP Project:

New PHP Project Dialog with "Create project at existing location" options badly circled

Rounding to two decimal places in Python 2.7?

You can use str.format(), too:

>>> print "financial return of outcome 1 = {:.2f}".format(1.23456)
financial return of outcome 1 = 1.23

Disable browser 'Save Password' functionality

I haven't had any issues using this method:

Use autocomplete="off", add a hidden password field and then another non-hidden one. The browser tries to auto complete the hidden one if it doesn't respect autocomplete="off"

In Angular, I need to search objects in an array

A dirty and easy solution could look like

$scope.showdetails = function(fish_id) {
    angular.forEach($scope.fish, function(fish, key) {
        fish.more = fish.id == fish_id;
    });
};

How to add Drop-Down list (<select>) programmatically?

This code would create a select list dynamically. First I create an array with the car names. Second, I create a select element dynamically and assign it to a variable "sEle" and append it to the body of the html document. Then I use a for loop to loop through the array. Third, I dynamically create the option element and assign it to a variable "oEle". Using an if statement, I assign the attributes 'disabled' and 'selected' to the first option element [0] so that it would be selected always and is disabled. I then create a text node array "oTxt" to append the array names and then append the text node to the option element which is later appended to the select element.

_x000D_
_x000D_
var array = ['Select Car', 'Volvo', 'Saab', 'Mervedes', 'Audi'];_x000D_
_x000D_
var sEle = document.createElement('select');_x000D_
document.getElementsByTagName('body')[0].appendChild(sEle);_x000D_
_x000D_
for (var i = 0; i < array.length; ++i) {_x000D_
  var oEle = document.createElement('option');_x000D_
_x000D_
  if (i == 0) {_x000D_
    oEle.setAttribute('disabled', 'disabled');_x000D_
    oEle.setAttribute('selected', 'selected');_x000D_
  } // end of if loop_x000D_
_x000D_
  var oTxt = document.createTextNode(array[i]);_x000D_
  oEle.appendChild(oTxt);_x000D_
_x000D_
  document.getElementsByTagName('select')[0].appendChild(oEle);_x000D_
} // end of for loop
_x000D_
_x000D_
_x000D_

Is it safe to expose Firebase apiKey to the public?

I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.

I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable. Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase. Go to https://console.developers.google.com/apis and perfrom a security steup.

Test if number is odd or even

I did a bit of testing, and found that between mod, is_int and the &-operator, mod is the fastest, followed closely by the &-operator. is_int is nearly 4 times slower than mod.

I used the following code for testing purposes:

$number = 13;

$before = microtime(true);
for ($i=0; $i<100000; $i++) {
    $test = ($number%2?true:false);
}
$after = microtime(true);

echo $after-$before." seconds mod<br>";

$before = microtime(true);
for ($i=0; $i<100000; $i++) {
    $test = (!is_int($number/2)?true:false);
}
$after = microtime(true);

echo $after-$before." seconds is_int<br>";

$before = microtime(true);
for ($i=0; $i<100000; $i++) {
    $test = ($number&1?true:false);
}
$after = microtime(true);

echo $after-$before." seconds & operator<br>";

The results I got were pretty consistent. Here's a sample:

0.041879177093506 seconds mod
0.15969395637512 seconds is_int
0.044223070144653 seconds & operator

A warning - comparison between signed and unsigned integer expressions

The primary issue is that underlying hardware, the CPU, only has instructions to compare two signed values or compare two unsigned values. If you pass the unsigned comparison instruction a signed, negative value, it will treat it as a large positive number. So, -1, the bit pattern with all bits on (twos complement), becomes the maximum unsigned value for the same number of bits.

8-bits: -1 signed is the same bits as 255 unsigned 16-bits: -1 signed is the same bits as 65535 unsigned etc.

So, if you have the following code:

int fd;
fd = open( .... );

int cnt;
SomeType buf;

cnt = read( fd, &buf, sizeof(buf) );

if( cnt < sizeof(buf) ) {
    perror("read error");
}

you will find that if the read(2) call fails due to the file descriptor becoming invalid (or some other error), that cnt will be set to -1. When comparing to sizeof(buf), an unsigned value, the if() statement will be false because 0xffffffff is not less than sizeof() some (reasonable, not concocted to be max size) data structure.

Thus, you have to write the above if, to remove the signed/unsigned warning as:

if( cnt < 0 || (size_t)cnt < sizeof(buf) ) {
    perror("read error");
}

This just speaks loudly to the problems.

1.  Introduction of size_t and other datatypes was crafted to mostly work, 
    not engineered, with language changes, to be explicitly robust and 
    fool proof.
2.  Overall, C/C++ data types should just be signed, as Java correctly
    implemented.

If you have values so large that you can't find a signed value type that works, you are using too small of a processor or too large of a magnitude of values in your language of choice. If, like with money, every digit counts, there are systems to use in most languages which provide you infinite digits of precision. C/C++ just doesn't do this well, and you have to be very explicit about everything around types as mentioned in many of the other answers here.

When should I use a List vs a LinkedList

My previous answer was not enough accurate. As truly it was horrible :D But now I can post much more useful and correct answer.


I did some additional tests. You can find it's source by the following link and reCheck it on your environment by your own: https://github.com/ukushu/DataStructuresTestsAndOther.git

Short results:

  • Array need to use:

    • So often as possible. It's fast and takes smallest RAM range for same amount information.
    • If you know exact count of cells needed
    • If data saved in array < 85000 b (85000/32 = 2656 elements for integer data)
    • If needed high Random Access speed
  • List need to use:

    • If needed to add cells to the end of list (often)
    • If needed to add cells in the beginning/middle of the list (NOT OFTEN)
    • If data saved in array < 85000 b (85000/32 = 2656 elements for integer data)
    • If needed high Random Access speed
  • LinkedList need to use:

    • If needed to add cells in the beginning/middle/end of the list (often)
    • If needed only sequential access (forward/backward)
    • If you need to save LARGE items, but items count is low.
    • Better do not use for large amount of items, as it's use additional memory for links.

More details:

??????? ???? ???????? ??????????? Interesting to know:

  1. LinkedList<T> internally is not a List in .NET. It's even does not implement IList<T>. And that's why there are absent indexes and methods related to indexes.

  2. LinkedList<T> is node-pointer based collection. In .NET it's in doubly linked implementation. This means that prior/next elements have link to current element. And data is fragmented -- different list objects can be located in different places of RAM. Also there will be more memory used for LinkedList<T> than for List<T> or Array.

  3. List<T> in .Net is Java's alternative of ArrayList<T>. This means that this is array wrapper. So it's allocated in memory as one contiguous block of data. If allocated data size exceeds 85000 bytes, it will be moved to Large Object Heap. Depending on the size, this can lead to heap fragmentation(a mild form of memory leak). But in the same time if size < 85000 bytes -- this provides a very compact and fast-access representation in memory.

  4. Single contiguous block is preferred for random access performance and memory consumption but for collections that need to change size regularly a structure such as an Array generally need to be copied to a new location whereas a linked list only needs to manage the memory for the newly inserted/deleted nodes.

JavaScript inside an <img title="<a href='#' onClick='alert('Hello World!')>The Link</a>" /> possible?

<img title="<a href="javascript:alert('hello world')">The Link</a>" /> 

Solving "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection" InvalidOperationException

If you're using ASP.NET Core and wonder why you get this message in one of your async controller methods, make sure you return a Task rather than void - ASP.NET Core disposes injected contexts.

(I'm posting this answer as this question is high in the search results to that exception message and it's a subtle issue - maybe it's useful to people who Google for it.)

How do you create a dropdownlist from an enum in ASP.NET MVC?

In .NET Core you can just use this:

@Html.DropDownListFor(x => x.Foo, Html.GetEnumSelectList<MyEnum>())

T-SQL stored procedure that accepts multiple Id values

Try This One:

@list_of_params varchar(20) -- value 1, 2, 5, 7, 20 

SELECT d.[Name]
FROM Department d
where @list_of_params like ('%'+ CONVERT(VARCHAR(10),d.Id)  +'%')

very simple.

How to get list of dates between two dates in mysql select query

Try:

select * from 
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date from
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where selected_date between '2012-02-10' and '2012-02-15'

-for date ranges up to nearly 300 years in the future.

[Corrected following a suggested edit by UrvishAtSynapse.]

String strip() for JavaScript?

If, rather than writing new code to trim a string, you're looking at existing code that calls "strip()" and wondering why it isn't working, you might want to check whether it attempts to include something like the prototypejs framework, and make sure it's actually getting loaded.
That framework adds a strip function to all String objects, but if e.g. you upgraded it and your web pages are still referring to the old .js file it'll of course not work.

Send POST parameters with MultipartFormData using Alamofire, in iOS Swift

For Swift 4.2 / Alamofire 4.7.3

Alamofire.upload(multipartFormData: { multipart in
    multipart.append(fileData, withName: "payload", fileName: "someFile.jpg", mimeType: "image/jpeg")
    multipart.append("comment".data(using: .utf8)!, withName :"comment")
}, to: "endPointURL", method: .post, headers: nil) { encodingResult in
    switch encodingResult {
    case .success(let upload, _, _):
        upload.response { answer in
            print("statusCode: \(answer.response?.statusCode)")
        }
        upload.uploadProgress { progress in
            //call progress callback here if you need it
        }
    case .failure(let encodingError):
        print("multipart upload encodingError: \(encodingError)")
    }
}

Also you could take a look at CodyFire lib it makes API calls easier using Codable for everything. Example for Multipart call using CodyFire

//Declare your multipart payload model
struct MyPayload: MultipartPayload {
    var attachment: Attachment //or you could use just Data instead
    var comment: String
}

// Prepare payload for request
let imageAttachment = Attachment(data: UIImage(named: "cat")!.jpeg(.high)!,
                                 fileName: "cat.jpg",
                                 mimeType: .jpg)
let payload = MyPayload(attachment: imageAttachment, comment: "Some text")

//Send request easily
APIRequest("endpoint", payload: payload)
    .method(.post)
    .desiredStatus(.created) //201 CREATED
    .onError { error in
        switch error.code {
        case .notFound: print("Not found")
        default: print("Another error: " + error.description)
        }
    }.onSuccess { result in
        print("here is your decoded result")
    }
//Btw normally it should be wrapped into an extension
//so it should look even easier API.some.upload(payload).onError{}.onSuccess{}

You could take a look at all the examples in lib's readme

Use of 'prototype' vs. 'this' in JavaScript?

I believe that @Matthew Crumley is right. They are functionally, if not structurally, equivalent. If you use Firebug to look at the objects that are created using new, you can see that they are the same. However, my preference would be the following. I'm guessing that it just seems more like what I'm used to in C#/Java. That is, define the class, define the fields, constructor, and methods.

var A = function() {};
A.prototype = {
    _instance_var: 0,

    initialize: function(v) { this._instance_var = v; },

    x: function() {  alert(this._instance_var); }
};

EDIT Didn't mean to imply that the scope of the variable was private, I was just trying to illustrate how I define my classes in javascript. Variable name has been changed to reflect this.

Writing binary number system in C code

Standard C doesn't define binary constants. There's a GNU (I believe) extension though (among popular compilers, clang adapts it as well): the 0b prefix:

int foo = 0b1010;

If you want to stick with standard C, then there's an option: you can combine a macro and a function to create an almost readable "binary constant" feature:

#define B(x) S_to_binary_(#x)

static inline unsigned long long S_to_binary_(const char *s)
{
        unsigned long long i = 0;
        while (*s) {
                i <<= 1;
                i += *s++ - '0';
        }
        return i;
}

And then you can use it like this:

int foo = B(1010);

If you turn on heavy compiler optimizations, the compiler will most likely eliminate the function call completely (constant folding) or will at least inline it, so this won't even be a performance issue.

Proof:

The following code:

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <string.h>


#define B(x) S_to_binary_(#x)

static inline unsigned long long S_to_binary_(const char *s)
{
    unsigned long long i = 0;
    while (*s) {
        i <<= 1;
        i += *s++ - '0';
    }
    return i;
}

int main()
{
    int foo = B(001100101);

    printf("%d\n", foo);

    return 0;
}

has been compiled using clang -o baz.S baz.c -Wall -O3 -S, and it produced the following assembly:

    .section    __TEXT,__text,regular,pure_instructions
    .globl  _main
    .align  4, 0x90
_main:                                  ## @main
    .cfi_startproc
## BB#0:
    pushq   %rbp
Ltmp2:
    .cfi_def_cfa_offset 16
Ltmp3:
    .cfi_offset %rbp, -16
    movq    %rsp, %rbp
Ltmp4:
    .cfi_def_cfa_register %rbp
    leaq    L_.str1(%rip), %rdi
    movl    $101, %esi               ## <= This line!
    xorb    %al, %al
    callq   _printf
    xorl    %eax, %eax
    popq    %rbp
    ret
    .cfi_endproc

    .section    __TEXT,__cstring,cstring_literals
L_.str1:                                ## @.str1
    .asciz   "%d\n"


.subsections_via_symbols

So clang completely eliminated the call to the function, and replaced its return value with 101. Neat, huh?

mongo - couldn't connect to server 127.0.0.1:27017

if u install by brew (on osx) first run sudo mkdir /data/db start mondoDB Daemon by typing mongod (leave it open) and then run mongo by typing mongo in new terminal tab

Iterating over JSON object in C#

This worked for me, converts to nested JSON to easy to read YAML

    string JSONDeserialized {get; set;}
    public int indentLevel;

    private bool JSONDictionarytoYAML(Dictionary<string, object> dict)
    {
        bool bSuccess = false;
        indentLevel++;

        foreach (string strKey in dict.Keys)
        {
            string strOutput = "".PadLeft(indentLevel * 3) + strKey + ":";
            JSONDeserialized+="\r\n" + strOutput;

            object o = dict[strKey];
            if (o is Dictionary<string, object>)
            {
                JSONDictionarytoYAML((Dictionary<string, object>)o);
            }
            else if (o is ArrayList)
            {
                foreach (object oChild in ((ArrayList)o))
                {
                    if (oChild is string)
                    {
                        strOutput = ((string)oChild);
                        JSONDeserialized += strOutput + ",";
                    }
                    else if (oChild is Dictionary<string, object>)
                    {
                        JSONDictionarytoYAML((Dictionary<string, object>)oChild);
                        JSONDeserialized += "\r\n";  
                    }
                }
            }
            else
            {
                strOutput = o.ToString();
                JSONDeserialized += strOutput;
            }
        }

        indentLevel--;

        return bSuccess;

    }

usage

        Dictionary<string, object> JSONDic = new Dictionary<string, object>();
        JavaScriptSerializer js = new JavaScriptSerializer();

          try {

            JSONDic = js.Deserialize<Dictionary<string, object>>(inString);
            JSONDeserialized = "";

            indentLevel = 0;
            DisplayDictionary(JSONDic); 

            return JSONDeserialized;

        }
        catch (Exception)
        {
            return "Could not parse input JSON string";
        }

Create a tar.xz in one command

Try this: tar -cf file.tar file-to-compress ; xz -z file.tar

Note:

  1. tar.gz and tar.xz are not the same; xz provides better compression.
  2. Don't use pipe | because this runs commands simultaneously. Using ; or & executes commands one after another.

Intellij reformat on file save

I set it to automatically clean up on check-in, which is usually good enough for me. If something is too ugly, I'll just hit the shortcut (Ctrl-Alt-L, Return). And I see they have an option for auto-formatting pasted code, although I've never used that.

Interview Question: Merge two sorted singly linked lists without creating new nodes

Iteration can be done as below. Complexity = O(n)

public static LLNode mergeSortedListIteration(LLNode nodeA, LLNode nodeB) {
    LLNode mergedNode ;
    LLNode tempNode ;      

    if (nodeA == null) {
        return nodeB;
      } 
      if (nodeB == null) {
        return nodeA;
      }     


    if ( nodeA.getData() < nodeB.getData())
    {
        mergedNode = nodeA;
        nodeA = nodeA.getNext();
    }
    else
    {
        mergedNode = nodeB;
        nodeB = nodeB.getNext();
    }

    tempNode = mergedNode; 

    while (nodeA != null && nodeB != null)
    {           

        if ( nodeA.getData() < nodeB.getData())
        {               
            mergedNode.setNext(nodeA);
            nodeA = nodeA.getNext();
        }
        else
        {
            mergedNode.setNext(nodeB);
            nodeB = nodeB.getNext();                
        }       
        mergedNode = mergedNode.getNext();
    }

    if (nodeA != null)
    {
        mergedNode.setNext(nodeA);
    }

    if (nodeB != null)
    {
        mergedNode.setNext(nodeB);
    }       
    return tempNode;
}

Python, add items from txt file into a list

names=[line.strip() for line in open('names.txt')]

Sticky Header after scrolling down

Here is a JS fiddle http://jsfiddle.net/ke9kW/1/

As the others say, set the header to fixed, and start it with display: none

then jQuery

$(window).scroll(function () {
  if ( $(this).scrollTop() > 200 && !$('header').hasClass('open') ) {
    $('header').addClass('open');
    $('header').slideDown();
   } else if ( $(this).scrollTop() <= 200 ) {
    $('header').removeClass('open');
    $('header').slideUp();
  }
});

where 200 is the height in pixels you'd like it to move down at. The addition of the open class is to allow us to run an elseif instead of just else, so some of the code doesn't unnecessarily run on every scrollevent, save a lil bit of memory

Force index use in Oracle

There could be many reasons for Index not being used. Even after you specify hints, there are chances Oracle optimizer thinks otherwise and decide not to use Index. You need to go through the EXPLAIN PLAN part and see what is the cost of the statement with INDEX and without INDEX.

Assuming the Oracle uses CBO. Most often, if the optimizer thinks the cost is high with INDEX, even though you specify it in hints, the optimizer will ignore and continue for full table scan. Your first action should be checking DBA_INDEXES to know when the statistics are LAST_ANALYZED. If not analyzed, you can set table, index for analyze.

begin 
   DBMS_STATS.GATHER_INDEX_STATS ( OWNNAME=>user
                                 , INDNAME=>IndexName);
end;

For table.

begin 
   DBMS_STATS.GATHER_TABLE_STATS ( OWNNAME=>user
                                 , TABNAME=>TableName);
end;

In extreme cases, you can try setting up the statistics on your own.

MetadataException when using Entity Framework Entity Connection

I moved my Database First DataModel to a different project midway through development. Poor planning (or lack there of) on my part.

Initially I had a solution with one project. Then I added another project to the solution and recreated my Database First DataModel from the Sql Server Dataase.

To fix the problem - MetadataException when using Entity Framework Entity Connection. I copied my the ConnectionString from the new Project Web.Config to the original project Web.Config. However, this occurred after I updated my all the references in the original project to new DataModel project.

Execute another jar in a Java program

The following works by starting the jar with a batch file, in case the program runs as a stand alone:

public static void startExtJarProgram(){
        String extJar = Paths.get("C:\\absolute\\path\\to\\batchfile.bat").toString();
        ProcessBuilder processBuilder = new ProcessBuilder(extJar);
        processBuilder.redirectError(new File(Paths.get("C:\\path\\to\\JavaProcessOutput\\extJar_out_put.txt").toString()));
        processBuilder.redirectInput();
        try {
           final Process process = processBuilder.start();
            try {
                final int exitStatus = process.waitFor();
                if(exitStatus==0){
                    System.out.println("External Jar Started Successfully.");
                    System.exit(0); //or whatever suits 
                }else{
                    System.out.println("There was an error starting external Jar. Perhaps path issues. Use exit code "+exitStatus+" for details.");
                    System.out.println("Check also C:\\path\\to\\JavaProcessOutput\\extJar_out_put.txt file for additional details.");
                    System.exit(1);//whatever
                }
            } catch (InterruptedException ex) {
                System.out.println("InterruptedException: "+ex.getMessage());
            }
        } catch (IOException ex) {
            System.out.println("IOException. Faild to start process. Reason: "+ex.getMessage());
        }
        System.out.println("Process Terminated.");
        System.exit(0);
    }

In the batchfile.bat then we can say:

@echo off
start /min C:\path\to\jarprogram.jar

Why is it string.join(list) instead of list.join(string)?

It's because any iterable can be joined (e.g, list, tuple, dict, set), but its contents and the "joiner" must be strings.

For example:

'_'.join(['welcome', 'to', 'stack', 'overflow'])
'_'.join(('welcome', 'to', 'stack', 'overflow'))
'welcome_to_stack_overflow'

Using something other than strings will raise the following error:

TypeError: sequence item 0: expected str instance, int found

How to checkout in Git by date?

To keep your current changes

You can keep your work stashed away, without commiting it, with git stash. You would than use git stash pop to get it back. Or you can (as carleeto said) git commit it to a separate branch.

Checkout by date using rev-parse

You can checkout a commit by a specific date using rev-parse like this:

git checkout 'master@{1979-02-26 18:30:00}'

More details on the available options can be found in the git-rev-parse.

As noted in the comments this method uses the reflog to find the commit in your history. By default these entries expire after 90 days. Although the syntax for using the reflog is less verbose you can only go back 90 days.

Checkout out by date using rev-list

The other option, which doesn't use the reflog, is to use rev-list to get the commit at a particular point in time with:

git checkout `git rev-list -n 1 --first-parent --before="2009-07-27 13:37" master`

Note the --first-parent if you want only your history and not versions brought in by a merge. That's what you usually want.

Calling a Function defined inside another function in Javascript

The scoping is correct as you've noted. However, you are not calling the inner function anywhere.

You can do either:

function outer() { 

    // when you define it this way, the inner function will be accessible only from 
    // inside the outer function

    function inner() {
        alert("hi");
    }
    inner(); // call it
}

Or

function outer() { 
    this.inner = function() {
        alert("hi");
    }
}

<input type="button" onclick="(new outer()).inner();" value="ACTION">?

Passing multiple parameters with $.ajax url

Why are you combining GET and POST? Use one or the other.

$.ajax({
    type: 'post',
    data: {
        timestamp: timestamp,
        uid: uid
        ...
    }
});

php:

$uid =$_POST['uid'];

Or, just format your request properly (you're missing the ampersands for the get parameters).

url:"getdata.php?timestamp="+timestamp+"&uid="+id+"&uname="+name,

Bootstrap modal: is not a function

I added a modal dialog in jsp and tried to open it with javascript in jsx and hit the same error: "...modal is not a function"

In my case, simply by adding the missing import to the jsx solved the problem.

`import "./../bower/bootstrap/js/modal.js"; // or import ".../bootstrap.min.js"` 

How to link a folder with an existing Heroku app

Don't forget, if you are also on a machine where you haven't set up heroku before

heroku keys:add

Or you won't be able to push or pull to the repo.

LINQ Orderby Descending Query

Just to show it in a different format that I prefer to use for some reason: The first way returns your itemList as an System.Linq.IOrderedQueryable

using(var context = new ItemEntities())
{
    var itemList = context.Items.Where(x => !x.Items && x.DeliverySelection)
                                .OrderByDescending(x => x.Delivery.SubmissionDate);
}

That approach is fine, but if you wanted it straight into a List Object:

var itemList = context.Items.Where(x => !x.Items && x.DeliverySelection)
                                .OrderByDescending(x => x.Delivery.SubmissionDate).ToList();

All you have to do is append a .ToList() call to the end of the Query.

Something to note, off the top of my head I can't recall if the !(not) expression is acceptable in the Where() call.

How to get the current date and time of your timezone in Java?

You would use JodaTime for that. Java.util.Date is very limited regarding TimeZone.

How to print a date in a regular format?

With type-specific datetime string formatting (see nk9's answer using str.format().) in a Formatted string literal (since Python 3.6, 2016-12-23):

>>> import datetime
>>> f"{datetime.datetime.now():%Y-%m-%d}"
'2017-06-15'

The date/time format directives are not documented as part of the Format String Syntax but rather in date, datetime, and time's strftime() documentation. The are based on the 1989 C Standard, but include some ISO 8601 directives since Python 3.6.

WHERE IS NULL, IS NOT NULL or NO WHERE clause depending on SQL Server parameter value

You could just do something like this:

SELECT *
FROM foo
WHERE (@param = 0 AND MyColumn IS NULL)
OR (@param = 1 AND MyColumn IS NOT NULL)
OR (@param = 2)

Something like that.

current/duration time of html5 video?

This page might help you out. Everything you need to know about HTML5 video and audio

var video = document.createElement('video');
var curtime = video.currentTime;

If you already have the video element, .currentTime should work. If you need more details, that webpage should be able to help.

How to cast DATETIME as a DATE in mysql?

Use DATE() function:

select * from follow_queue group by DATE(follow_date)

How to update maven repository in Eclipse?

If Maven update snapshot doesn't work and if you have Spring Tooling, one interesting way is to remove

  • Right-click on your project then Maven > Disable Maven Nature
  • Right-click on your project then Spring Tools > Update Maven Dependencies
  • After "BUILD SUCCESS", Right-click on your project then Configure > Convert Maven Project

Note: Maven update snapshot sometimes stops working if you use anything else i.e. eclipse:eclipse or Spring Tooling

How to remove files that are listed in the .gitignore but still on the repository?

I can't say it's an appropriate solution but you can try this.

Steps

  • I am hoping that you have already cloned your repo.
  • Now copy the file somewhere outside of your project.
  • Add that filename with a location in gitigonre file.
  • Remove that file from your local project.
  • Push your code to remote origin.
  • And now add that copied file into your project it'll be ignored.

This is just a hack solution if you want to maintain the history and don't to create mass in it.

If you don't want to use this solution please kindly ignore and try to avoid devote it. Because I am really trying to increase my score on this side

How to set the JDK Netbeans runs on?

I had this message too because today i decided to relocate my different jdk in the same directory. I have decided to uninstall all through program manager of window. After that, of course i had the message below.

"Cannot locate java installation in specified jdkhome C:\Program Files (x86)\Java\jdk1.7.0_60 Do you want to try to use default version ?"

A new install of the jdk does not resolve the problem. Ok you can configure that in menu Tool > java platforms but in my case i had to fix my netbeans.conf

i had the line below

netbeans_jdkhome="C:\Program Files\Java\jdk1.7.0_60"

and i replace it by

netbeans_jdkhome="C:\devtools\Java\jdk1.8.0_25"

how to fix java.lang.IndexOutOfBoundsException

This error happens because your list lstpp is empty (Nothing at index 0). So either there is a bug in your getResult() function, or the empty list is normal and you need to handle this case (By checking the size of the list before, or catching the exception).

Rails migration for change column

Just generate migration:

rails g migration change_column_to_new_from_table_name

Update migration like this:

class ClassName < ActiveRecord::Migration
  change_table :table_name do |table|
    table.change :column_name, :data_type
  end
end

and finally

rake db:migrate

Multiple dex files define Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat

In my case the problem was caused by version inconsistency:

Build tools 25
compileSdk 24
targetSdk 24
Support library 24

The solution was simple: Make everything version 25

Creating Accordion Table with Bootstrap

For anyone who came here looking for how to get the true accordion effect and only allow one row to be expanded at a time, you can add an event handler for show.bs.collapse like so:

$('.collapse').on('show.bs.collapse', function () {
    $('.collapse.in').collapse('hide');
});

I modified this example to do so here: http://jsfiddle.net/QLfMU/116/

Getting "NoSuchMethodError: org.hamcrest.Matcher.describeMismatch" when running test in IntelliJ 10.5

This worked for me. No need to exclude anything. I just used mockito-core instead mockito-all

testCompile 'junit:junit:4.12'
testCompile group: 'org.mockito', name: 'mockito-core', version: '3.0.0'
testCompile group: 'org.hamcrest', name: 'hamcrest-library', version: '2.1'

How to create a bash script to check the SSH connection?

I feel like you're trying to solve the wrong problem here. Shouldn't you be trying to make the ssh daemons more stable? Try running something like monit, which will check to see if the daemon is running and restart it if it isn't (giving you time to find the root problem behind sshd shutting down on you). Or is the network service troublesome? Try looking at man ifup. Does the Whole Damn Thing just like to shut down on you? Well, that's a bigger problem ... try looking at your logs (start with syslog) to find hardware failures or services that are shutting your boxen down (maybe a temperature monitor?).

Making your scripts fault tolerant is great, but you might also want to make your boxen fault tolerant.

How to loop through key/value object in Javascript?

Beware of properties inherited from the object's prototype (which could happen if you're including any libraries on your page, such as older versions of Prototype). You can check for this by using the object's hasOwnProperty() method. This is generally a good idea when using for...in loops:

var user = {};

function setUsers(data) {
    for (var k in data) {
        if (data.hasOwnProperty(k)) {
           user[k] = data[k];
        }
    }
}

Cannot set property 'display' of undefined

I've found this answer in the site https://plainjs.com/javascript/styles/set-and-get-css-styles-of-elements-53/.

In this code we add multiple styles in an element:

_x000D_
_x000D_
let_x000D_
    element = document.querySelector('span')_x000D_
  , cssStyle = (el, styles) => {_x000D_
      for (var property in styles) {_x000D_
          el.style[property] = styles[property];_x000D_
      }_x000D_
  }_x000D_
;_x000D_
_x000D_
cssStyle(element, { background:'tomato', color: 'white', padding: '0.5rem 1rem'});
_x000D_
span{_x000D_
font-family: sans-serif;_x000D_
color: #323232;_x000D_
background: #fff;_x000D_
}
_x000D_
<span>_x000D_
lorem ipsum_x000D_
</span>
_x000D_
_x000D_
_x000D_

What is the proper REST response code for a valid request but an empty data?

According to Microsoft: Controller action return types in ASP.NET Core web API, scroll down almost to the bottom, you find the following blurb about 404 relating to an object not found in the database. Here they suggest that a 404 is appropriate for Empty Data.

enter image description here

how to make a jquery "$.post" request synchronous

If you want an synchronous request set the async property to false for the request. Check out the jQuery AJAX Doc

Flutter plugin not installed error;. When running flutter doctor

If you are using VSCode then navigate to extensions and search for flutter.Then simply install it and must take care that you have already installed dart there and after that if it doesn't work then copy your flutter bin path that you can locate at C/'flutter-SDK-path'/bin.then copy it and add it to environment variable and add it to that path so,you can easily be able to access flutter.I hope it works.

If you are using Android Studio then may already stated article help you. And make sure that you have latest versions of SDKs and Android Studio or VSCode.so that versions can't introduce any error. Hope it work.

How to save password when using Subversion from the console

I'm using the TortoiseSVN client on Windows, and for me, setting store-passwords parameter as yes in %USERPROFILE%\AppData\Roaming\Subversion\config does not help to store the password.

The password was successfully saved after removing this folder (just in case renaming):

%USERPROFILE%\AppData\Roaming\Subversion\auth

Environment:

Windows 7, TortoiseSVN 1.7.11 (Build 23600 - 64 bit, 2012-12-12T19:08:52), Subversion 1.7.8.

How to get the changes on a branch in Git

What you want to see is the list of outgoing commits. You can do this using

git log master..branchName 

or

git log master..branchName --oneline

Where I assume that "branchName" was created as a tracking branch of "master".

Similarly, to see the incoming changes you can use:

git log branchName..master

Map enum in JPA with fixed values?

I would do the folowing:

Declare separetly the enum, in it´s own file:

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

      private int value;

      private RightEnum (int value) { this.value = value; }


      @Override
      public static Etapa valueOf(Integer value){
           for( RightEnum r : RightEnum .values() ){
              if ( r.getValue().equals(value))
                 return r;
           }
           return null;//or throw exception
     }

      public int getValue() { return value; }


}

Declare a new JPA entity named Right

@Entity
public class Right{
    @Id
    private Integer id;
    //FIElDS

    // constructor
    public Right(RightEnum rightEnum){
          this.id = rightEnum.getValue();
    }

    public Right getInstance(RightEnum rightEnum){
          return new Right(rightEnum);
    }


}

You will also need a converter for receiving this values (JPA 2.1 only and there´s a problem I´ll not discuss here with these enum´s to be directly persisted using the converter, so it will be a one way road only)

import mypackage.RightEnum;
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;

/**
 * 
 * 
 */
@Converter(autoApply = true)
public class RightEnumConverter implements AttributeConverter<RightEnum, Integer>{

    @Override //this method shoudn´t be used, but I implemented anyway, just in case
    public Integer convertToDatabaseColumn(RightEnum attribute) {
        return attribute.getValue();
    }

    @Override
    public RightEnum convertToEntityAttribute(Integer dbData) {
        return RightEnum.valueOf(dbData);
    }

}

The Authority entity:

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


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

  // the **Entity** to map : 
  private Right right;

  // the **Enum** to map (not to be persisted or updated) : 
  @Column(name="COLUMN1", insertable = false, updatable = false)
  @Convert(converter = RightEnumConverter.class)
  private RightEnum rightEnum;

}

By doing this way, you can´t set directly to the enum field. However, you can set the Right field in Authority using

autorithy.setRight( Right.getInstance( RightEnum.READ ) );//for example

And if you need to compare, you can use:

authority.getRight().equals( RightEnum.READ ); //for example

Which is pretty cool, I think. It´s not totally correct, since the converter it´s not intended to be use with enum´s. Actually, the documentation says to never use it for this purpose, you should use the @Enumerated annotation instead. The problem is that there are only two enum types: ORDINAL or STRING, but the ORDINAL is tricky and not safe.


However, if it doesn´t satisfy you, you can do something a little more hacky and simpler (or not).

Let´s see.

The RightEnum:

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

      private int value;

      private RightEnum (int value) { 
            try {
                  this.value= value;
                  final Field field = this.getClass().getSuperclass().getDeclaredField("ordinal");
                  field.setAccessible(true);
                  field.set(this, value);
             } catch (Exception e) {//or use more multicatch if you use JDK 1.7+
                  throw new RuntimeException(e);
            }
      }


      @Override
      public static Etapa valueOf(Integer value){
           for( RightEnum r : RightEnum .values() ){
              if ( r.getValue().equals(value))
                 return r;
           }
           return null;//or throw exception
     }

      public int getValue() { return value; }


}

and the Authority entity

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


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


  // the **Enum** to map (to be persisted or updated) : 
  @Column(name="COLUMN1")
  @Enumerated(EnumType.ORDINAL)
  private RightEnum rightEnum;

}

In this second idea, its not a perfect situation since we hack the ordinal attribute, but it´s a much smaller coding.

I think that the JPA specification should include the EnumType.ID where the enum value field should be annotated with some kind of @EnumId annotation.

Save PL/pgSQL output from PostgreSQL to a CSV file

I had to use the \COPY because I received the error message:

ERROR:  could not open file "/filepath/places.csv" for writing: Permission denied

So I used:

\Copy (Select address, zip  From manjadata) To '/filepath/places.csv' With CSV;

and it is functioning

MySQL WHERE: how to write "!=" or "not equals"?

You may be using old version of Mysql but surely you can use

 DELETE FROM konta WHERE taken <> ''

But there are many other options available. You can try the following ones

DELETE * from konta WHERE strcmp(taken, '') <> 0;

DELETE * from konta where NOT (taken = '');

Python division

It has to do with the version of python that you use. Basically it adopts the C behavior: if you divide two integers, the results will be rounded down to an integer. Also keep in mind that Python does the operations from left to right, which plays a role when you typecast.

Example: Since this is a question that always pops in my head when I am doing arithmetic operations (should I convert to float and which number), an example from that aspect is presented:

>>> a = 1/2/3/4/5/4/3
>>> a
0

When we divide integers, not surprisingly it gets lower rounded.

>>> a = 1/2/3/4/5/4/float(3)
>>> a
0.0

If we typecast the last integer to float, we will still get zero, since by the time our number gets divided by the float has already become 0 because of the integer division.

>>> a = 1/2/3/float(4)/5/4/3
>>> a
0.0

Same scenario as above but shifting the float typecast a little closer to the left side.

>>> a = float(1)/2/3/4/5/4/3
>>> a
0.0006944444444444445

Finally, when we typecast the first integer to float, the result is the desired one, since beginning from the first division, i.e. the leftmost one, we use floats.

Extra 1: If you are trying to answer that to improve arithmetic evaluation, you should check this

Extra 2: Please be careful of the following scenario:

>>> a = float(1/2/3/4/5/4/3)
>>> a
0.0

Change key pair for ec2 instance

Alternate solution. If you have the only access on server. In that case don't remove pem file from AWS console. Just remove pem access key from sudo nano ~/.ssh/authroized_keys and add your system public ssh key. Now you have the access ssh [email protected]

How to get sp_executesql result into a variable?

Here's something you can try

DECLARE  @SqlStatement  NVARCHAR(MAX) = ''
       ,@result     XML
       ,@DatabaseName  VARCHAR(100)
       ,@SchemaName    VARCHAR(10)
       ,@ObjectName    VARCHAR(200);

SELECT   @DatabaseName = 'some database'
       ,@SchemaName   = 'some schema'
       ,@ObjectName   = 'some object (Table/View)'

SET @SqlStatement = '
                    SELECT @result = CONVERT(XML,
                                            STUFF( ( SELECT *
                                                     FROM 
                                                       (
                                                          SELECT TOP(100) 
                                                          * 
                                                          FROM ' + QUOTENAME(@DatabaseName) +'.'+ QUOTENAME(@SchemaName) +'.' + QUOTENAME(@ObjectName) + '
                                                       ) AS A1 
                                                    FOR XML PATH(''row''), ELEMENTS, ROOT(''recordset'')
                                                 ), 1, 0, '''')
                                       )
                ';

EXEC sp_executesql @SqlStatement,N'@result XML OUTPUT', @result = @result OUTPUT;

SELECT DISTINCT
    QUOTENAME(r.value('fn:local-name(.)', 'VARCHAR(200)')) AS ColumnName
FROM @result.nodes('//recordset/*/*') AS records(r)
ORDER BY ColumnName

Using GregorianCalendar with SimpleDateFormat

SimpleDateFormat.format() method takes a Date as a parameter. You can get a Date from a Calendar by calling its getTime() method:

public static String format(GregorianCalendar calendar) {
    SimpleDateFormat fmt = new SimpleDateFormat("dd-MMM-yyyy");
    fmt.setCalendar(calendar);
    String dateFormatted = fmt.format(calendar.getTime());

    return dateFormatted;
}

Also note that the months start at 0, so you probably meant:

int month = Integer.parseInt(splitDate[1]) - 1;

Get random boolean in Java

You can use the following for an unbiased result:

Random random = new Random();
//For 50% chance of true
boolean chance50oftrue = (random.nextInt(2) == 0) ? true : false;

Note: random.nextInt(2) means that the number 2 is the bound. the counting starts at 0. So we have 2 possible numbers (0 and 1) and hence the probability is 50%!

If you want to give more probability to your result to be true (or false) you can adjust the above as following!

Random random = new Random();

//For 50% chance of true
boolean chance50oftrue = (random.nextInt(2) == 0) ? true : false;

//For 25% chance of true
boolean chance25oftrue = (random.nextInt(4) == 0) ? true : false;

//For 40% chance of true
boolean chance40oftrue = (random.nextInt(5) < 2) ? true : false;

Check if space is in a string

There are a lot of ways to do that :

t = s.split(" ")
if len(t) > 1:
  print "several tokens"

To be sure it matches every kind of space, you can use re module :

import re
if re.search(r"\s", your_string):
  print "several words"

javac is not recognized as an internal or external command, operable program or batch file

try this.. I had it too but now it solved in XP..

C:\ YourFolder >set path=C:\Program Files\Java\jdk1.7.0_09\bin;
C:\ YourFolder >javac YourCode.java

react native get TextInput value

User in the init of class:

constructor() {
    super()
    this.state = {
        email: ''
    }
}

Then in some function:

handleSome = () => { console.log(this.state.email) };

And in the input:

<TextInput onChangeText={(email) => this.setState({email})}/>

How do I trim whitespace from a string?

You want strip():

myphrases = [" Hello ", " Hello", "Hello ", "Bob has a cat"]

for phrase in myphrases:
    print(phrase.strip())

pull out p-values and r-squared from a linear regression

r-squared: You can return the r-squared value directly from the summary object summary(fit)$r.squared. See names(summary(fit)) for a list of all the items you can extract directly.

Model p-value: If you want to obtain the p-value of the overall regression model, this blog post outlines a function to return the p-value:

lmp <- function (modelobject) {
    if (class(modelobject) != "lm") stop("Not an object of class 'lm' ")
    f <- summary(modelobject)$fstatistic
    p <- pf(f[1],f[2],f[3],lower.tail=F)
    attributes(p) <- NULL
    return(p)
}

> lmp(fit)
[1] 1.622665e-05

In the case of a simple regression with one predictor, the model p-value and the p-value for the coefficient will be the same.

Coefficient p-values: If you have more than one predictor, then the above will return the model p-value, and the p-value for coefficients can be extracted using:

summary(fit)$coefficients[,4]  

Alternatively, you can grab the p-value of coefficients from the anova(fit) object in a similar fashion to the summary object above.

Error inflating when extending a class

in my case I added such cyclic resource:

<drawable name="above_shadow">@drawable/above_shadow</drawable>

then changed to

<drawable name="some_name">@drawable/other_name</drawable>

and it worked

CodeIgniter -> Get current URL relative to base url

I don't know if there is such a function, but with $this->uri->uri_to_assoc() you get an associative array from the $_GET parameters. With this, and the controller you are in, you know how the URL looks like. In you above URL this would mean you would be in the controller dropbox and the array would be something like this:

array("derrek" => "shopredux", "ahahaha" => "hihihi");

With this you should be able to make such a function on your own.

Insert a background image in CSS (Twitter Bootstrap)

body {
    background-image: url(your image link);
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment:fixed;
    background-size: cover;
    background-color: #464646;
}

What is the right way to write my script 'src' url for a local development environment?

Write the src tag for calling the js file as

<script type='text/javascript' src='../Users/myUserName/Desktop/myPage.js'></script>

This should work.

BASH Syntax error near unexpected token 'done'

There's a way you can get this problem without having mixed newline problems (at least, in my shell, which is GNU bash v4.3.30):

#!/bin/bash
# foo.sh

function foo() {
    echo "I am quoting a thing `$1' inside a function."
}

while [ "$input" != "y" ]; do
    read -p "Hit `y' to continue: " -n 1 input
    echo
done

foo "What could possibly go wrong?"
$ ./foo.sh
./foo.sh: line 11: syntax error near unexpected token `done'
./foo.sh: line 11: `done'

This is because bash expands backticks inside double-quoted strings (see the bash manual on quoting and command substitution), and before finding a matching backtick, will interpret any additional double quotes as part of the command substitution:

$ echo "Command substitution happens inside double-quoted strings: `ls`"
Command substitution happens inside double-quoted strings: foo.sh
$ echo "..even with double quotes: `grep -E "^foo|wrong" foo.sh`"
..even with double quotes: foo "What could possibly go wrong?"

You can get around this by escaping the backticks in your string with a backslash, or by using a single-quoted string.

I'm not really sure why this only gives the one error message, but I think it has to do with the function definition:

#!/bin/bash
# a.sh

function a() {
    echo "Thing's `quoted'"
}
a
while true; do
    echo "Other `quote'"
done
#!/bin/bash
# b.sh

echo "Thing's `quoted'"
while true; do
    echo "Other `quote'"
done
$ ./a.sh
./a.sh: line 10: syntax error near unexpected token `done'
./a.sh: line 10: `done'
$ ./b.sh
./b.sh: command substitution: line 6: unexpected EOF while looking for matching `''
./b.sh: command substitution: line 9: syntax error: unexpected end of file
Thing's quote'
./b.sh: line 7: syntax error near unexpected token `done'
./b.sh: line 7: `done'

CSS-moving text from left to right

I am not sure if this is the correct solution but I have achieved this by redefining .marquee class just after animation CSS.

Check below:

<style>
#marquee-wrapper{
    width:700px;
    display:block;
    border:1px solid red;
}

div.marquee{
width:100px;
height:100px;
background:red;
position:relative;
animation:myfirst 5s;
-moz-animation:myfirst 5s; /* Firefox */
}

@-moz-keyframes myfirst /* Firefox */{
0%   {background:red; left:0px; top:0px;}
100% {background:red; left:100%; top:0px}
}
div.marquee{ 
left:700px; top:0px
}
</style>

<!-- HTMl COde -->

<p><b>Note:</b> This example does not work in Internet Explorer and Opera.</p>
<div id="marquee-wrapper">
<div class="marquee"></div>

Flask Download a File

You need to make sure that the value you pass to the directory argument is an absolute path, corrected for the current location of your application.

The best way to do this is to configure UPLOAD_FOLDER as a relative path (no leading slash), then make it absolute by prepending current_app.root_path:

@app.route('/uploads/<path:filename>', methods=['GET', 'POST'])
def download(filename):
    uploads = os.path.join(current_app.root_path, app.config['UPLOAD_FOLDER'])
    return send_from_directory(directory=uploads, filename=filename)

It is important to reiterate that UPLOAD_FOLDER must be relative for this to work, e.g. not start with a /.

A relative path could work but relies too much on the current working directory being set to the place where your Flask code lives. This may not always be the case.

Understanding the set() function

Python's sets (and dictionaries) will iterate and print out in some order, but exactly what that order will be is arbitrary, and not guaranteed to remain the same after additions and removals.

Here's an example of a set changing order after a lot of values are added and then removed:

>>> s = set([1,6,8])
>>> print(s)
{8, 1, 6}
>>> s.update(range(10,100000))
>>> for v in range(10, 100000):
    s.remove(v)
>>> print(s)
{1, 6, 8}

This is implementation dependent though, and so you should not rely upon it.

How to get the current date and time

import java.util.Date;   
Date now = new Date();

Note that the Date object is mutable and if you want to do anything sophisticated, use jodatime.

How to Get the Query Executed in Laravel 5? DB::getQueryLog() Returning Empty Array

(Laravel 5.2) I find the simplest way is just to add one code line to monitor the sql queries:

\DB::listen(function($sql) {var_dump($sql); });

Read all contacts' phone numbers in android

Code to get contact name (Ascending order) and number

For more reference: show contact in listview

Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME+" ASC");
        while (phones.moveToNext())
        {
            String name=phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
            String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));


        }
        phones.close();

React Native Responsive Font Size

import { Dimensions } from 'react-native';

const { width, fontScale } = Dimensions.get("window");

const styles = StyleSheet.create({
    fontSize: idleFontSize / fontScale,
});

fontScale get scale as per your device.

Convert php array to Javascript

For a multidimensional array in PHP4 you can use the following addition to the code posted by Udo G:

function js_str($s) {
   return '"'.addcslashes($s, "\0..\37\"\\").'"';
}

function js_array($array, $keys_array) {
  foreach ($array as $key => $value) {
    $new_keys_array = $keys_array;
    $new_keys_array[] = $key;
    if(is_array($value)) {          
      echo 'javascript_array';
      foreach($new_keys_array as $key) {
        echo '["'.$key.'"]';
      }
      echo ' = new Array();';

      js_array($value, $new_keys_array);
    } else {
      echo 'javascript_array';
      foreach($new_keys_array as $key) {
        echo '["'.$key.'"]';
      }
      echo ' = '.js_str($value).";";                        
    }
  } 
}

echo 'var javascript_array = new Array();';
js_array($php_array, array());

System.Runtime.InteropServices.COMException (0x800A03EC)

Try this as it worked for me...

  1. Go to "Start" -> "Run" and enter "dcomcnfg"
  2. This will bring up the component services window, expand out "Console Root" -> "Computers" -> "DCOM Config"
  3. Find "Microsoft Excel Application" in the list of components.
  4. Right click on the entry and select "Properties"
  5. Go to the "Identity" tab on the properties dialog.
  6. Select "The interactive user."

courtesy of Last paragraph mentioned in here

Only on Firefox "Loading failed for the <script> with source"

Today I ran into the exact same problem while working on a progressive web app (PWA) page and deleting some cache and service worker data for that page from Firefox. The dev console reported that none of the 4 Javascript files on the page would load anymore. The problem persisted in Safe mode, so it was not an add-on issue. The same script files loaded fine from other web pages on the same website. No amount of clearing the Firefox cache or wiping web page data from Firefox would help, nor would rebooting the Windows 10 PC. Chrome all the time worked fine on the problem page. In the end I did a restore of the entire Firefox profile folder from a day-old backup, and the problem was immediately gone, so it was not a problem with my PWA app. Apparently something in Firefox got corrupted.

Swift 3: Display Image from URL

let url = ("https://firebasestorage.googleapis.com/v0/b/qualityaudit-678a4.appspot.com/o/profile_images%2FBFA28EDD-9E15-4CC3-9AF8-496B91E74A11.png?alt=media&token=b4518b07-2147-48e5-93fb-3de2b768412d")


self.myactivityindecator.startAnimating()

let urlString = url
    guard let url = URL(string: urlString) else { return }
    URLSession.shared.dataTask(with: url)


{
(data, response, error) in
        if error != nil {
            print("Failed fetching image:", error!)
            return
        }

        guard let response = response as? HTTPURLResponse, response.statusCode == 200 else {
            print("error")
            return
        }

        DispatchQueue.main.async {
            let image = UIImage(data: data!)
        let myimageview = UIImageView(image: image)
            print(myimageview)
            self.imgdata.image = myimageview.image
self.myactivityindecator.stopanimating()

     }
  }.resume()

Is this the right way to clean-up Fragment back stack when leaving a deeply nested stack?

The other clean solution if you don't want to pop all stack entries...

getSupportFragmentManager().popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
getSupportFragmentManager().beginTransaction().replace(R.id.home_activity_container, fragmentInstance).addToBackStack(null).commit();

This will clean the stack first and then load a new fragment, so at any given point you'll have only single fragment in stack

What is the difference between .NET Core and .NET Standard Class Library project types?

When should we use one over the other?

The decision is a trade-off between compatibility and API access.

Use a .NET Standard library when you want to increase the number of applications that will be compatible with your library, and you are okay with a decrease in the .NET API surface area your library can access.

Use a .NET Core library when you want to increase the .NET API surface area your library can access, and you are okay with allowing only .NET Core applications to be compatible with your library.

For example, a library that targets .NET Standard 1.3 will be compatible with applications that target .NET Framework 4.6, .NET Core 1.0, Universal Windows Platform 10.0, and any other platform that supports .NET Standard 1.3. The library will not have access to some parts of the .NET API, though. For instance, the Microsoft.NETCore.CoreCLR package is compatible with .NET Core, but not with .NET Standard.

What is the difference between Class Library (.NET Standard) and Class Library (.NET Core)?

Compatibility: Libraries that target .NET Standard will run on any .NET Standard compliant runtime, such as .NET Core, .NET Framework, Mono/Xamarin. On the other hand, libraries that target .NET Core can only run on the .NET Core runtime.

API Surface Area: .NET Standard libraries come with everything in NETStandard.Library, whereas .NET Core libraries come with everything in Microsoft.NETCore.App. The latter includes approximately 20 additional libraries, some of which we can add manually to our .NET Standard library (such as System.Threading.Thread) and some of which are not compatible with the .NET Standard (such as Microsoft.NETCore.CoreCLR).

Also, .NET Core libraries specify a runtime and come with an application model. That's important, for instance, to make unit test class libraries runnable.

Why do both exist?

Ignoring libraries for a moment, the reason that .NET Standard exists is for portability; it defines a set of APIs that .NET platforms agree to implement. Any platform that implements a .NET Standard is compatible with libraries that target that .NET Standard. One of those compatible platforms is .NET Core.

Coming back to libraries, the .NET Standard library templates exist to run on multiple runtimes (at the expense of API surface area). Conversely, the .NET Core library templates exist to access more API surface area (at the expense of compatibility) and to specify a platform against which to build an executable.

Here is an interactive matrix that shows which .NET Standard supports which .NET implementation(s) and how much API surface area is available.

instanceof Vs getClass( )

Do you want to match a class exactly, e.g. only matching FileInputStream instead of any subclass of FileInputStream? If so, use getClass() and ==. I would typically do this in an equals, so that an instance of X isn't deemed equal to an instance of a subclass of X - otherwise you can get into tricky symmetry problems. On the other hand, that's more usually useful for comparing that two objects are of the same class than of one specific class.

Otherwise, use instanceof. Note that with getClass() you will need to ensure you have a non-null reference to start with, or you'll get a NullPointerException, whereas instanceof will just return false if the first operand is null.

Personally I'd say instanceof is more idiomatic - but using either of them extensively is a design smell in most cases.

Get records with max value for each group of grouped SQL results

My solution works only if you need retrieve only one column, however for my needs was the best solution found in terms of performance (it use only one single query!):

SELECT SUBSTRING_INDEX(GROUP_CONCAT(column_x ORDER BY column_y),',',1) AS xyz,
   column_z
FROM table_name
GROUP BY column_z;

It use GROUP_CONCAT in order to create an ordered concat list and then I substring to only the first one.

How to handle back button in activity

This is a simple way of doing something.

    @Override
        public void onBackPressed() {
            // do what you want to do when the "back" button is pressed.
            startActivity(new Intent(Activity.this, MainActivity.class));
            finish();
        }

I think there might be more elaborate ways of going about it, but I like simplicity. For example, I used the template above to make the user sign out of the application AND THEN go back to another activity of my choosing.

How to set or change the default Java (JDK) version on OS X?

First find out where do you store the environment variables-

  1. emacs
  2. bash_profile
  3. zshrc file

Steps to Set up the environment variable :-

  1. Download the jdk from JAVA

  2. install it by double click

  3. Now set-up environment variables in your file

    a. For emacs.profile you can use this link OR see the screenshot below

enter image description here

b. For ZSH profile setup -

1. export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_112.jdk/Contents/Home

2. source ~/.zshrc - Restart zshrc to reflect the changes.

3. echo $JAVA_HOME - make sure path is set up properly 
   ----> /Library/Java/JavaVirtualMachines/jdk1.8.0_112.jdk/Contents/Home

4. java -version 

   -->  java version "1.8.0_112"  Java(TM) SE Runtime Environment (build 1.8.0_112-b16)Java HotSpot(TM) 64-Bit Server VM (build 25.112-b16, mixed mode)

All set Now you can easily upgrade or degrade the JAVA version..

List distinct values in a vector in R

You can also use the sqldf package in R.

Z <- sqldf('SELECT DISTINCT tablename.columnname FROM tablename ')

How to reload a page using JavaScript

You can simply use

window.location=document.URL

where document.URL gets the current page URL and window.location reloads it.

Encoding as Base64 in Java

Google Guava is another choice to encode and decode Base64 data:

POM configuration:

<dependency>
   <artifactId>guava</artifactId>
   <groupId>com.google.guava</groupId>
   <type>jar</type>
   <version>14.0.1</version>
</dependency>

Sample code:

String inputContent = "Hello Vi?t Nam";
String base64String = BaseEncoding.base64().encode(inputContent.getBytes("UTF-8"));

// Decode
System.out.println("Base64:" + base64String); // SGVsbG8gVmnhu4d0IE5hbQ==
byte[] contentInBytes = BaseEncoding.base64().decode(base64String);
System.out.println("Source content: " + new String(contentInBytes, "UTF-8")); // Hello Vi?t Nam

Show Error on the tip of the Edit Text Android

With youredittext.equals("")you can know if user hasn't entered any letter.

Image.open() cannot identify image file - Python?

In my case.. I already had "from PIL import Image" in my code.

The error occurred for me because the image file was still in use (locked) by a previous operation in my code. I had to add a small delay or attempt to open the file in append mode in a loop, until that did not fail. Once that did not fail, it meant the file was no longer in use and I could continue and let PIL open the file. Here are the functions I used to check if the file is in use and wait for it to be available.

def is_locked(filepath):
    locked = None
    file_object = None
    if os.path.exists(filepath):
        try:
            buffer_size = 8
            # Opening file in append mode and read the first 8 characters.
            file_object = open(filepath, 'a', buffer_size)
            if file_object:
                locked = False
        except IOError as message:
            locked = True
        finally:
            if file_object:
                file_object.close()
    return locked

def wait_for_file(filepath):
    wait_time = 1
    while is_locked(filepath):
        time.sleep(wait_time)

Is there a way to break a list into columns?

The CSS solution is: http://www.w3.org/TR/css3-multicol/

The browser support is exactly what you'd expect..

It works "everywhere" except Internet Explorer 9 or older: http://caniuse.com/multicolumn

ul {
    -moz-column-count: 4;
    -moz-column-gap: 20px;
    -webkit-column-count: 4;
    -webkit-column-gap: 20px;
    column-count: 4;
    column-gap: 20px;
}

See: http://jsfiddle.net/pdExf/

If IE support is required, you'll have to use JavaScript, for example:

http://welcome.totheinter.net/columnizer-jquery-plugin/

Another solution is to fallback to normal float: left for only IE. The order will be wrong, but at least it will look similar:

See: http://jsfiddle.net/NJ4Hw/

<!--[if lt IE 10]>
<style>
li {
    width: 25%;
    float: left
}
</style>
<![endif]-->

You could apply that fallback with Modernizr if you're already using it.

Correct way to initialize empty slice

The two alternative you gave are semantically identical, but using make([]int, 0) will result in an internal call to runtime.makeslice (Go 1.14).

You also have the option to leave it with a nil value:

var myslice []int

As written in the Golang.org blog:

a nil slice is functionally equivalent to a zero-length slice, even though it points to nothing. It has length zero and can be appended to, with allocation.

A nil slice will however json.Marshal() into "null" whereas an empty slice will marshal into "[]", as pointed out by @farwayer.

None of the above options will cause any allocation, as pointed out by @ArmanOrdookhani.

Forward request headers from nginx proxy server

If you want to pass the variable to your proxy backend, you have to set it with the proxy module.

location / {
    proxy_pass                      http://example.com;
    proxy_set_header                Host example.com;
    proxy_set_header                HTTP_Country-Code $geoip_country_code;
    proxy_pass_request_headers      on;
}

And now it's passed to the proxy backend.

How to make a rest post call from ReactJS code?

you can install superagent

npm install superagent --save

then for make post call to server

import request from "../../node_modules/superagent/superagent";

request
.post('http://localhost/userLogin')
.set('Content-Type', 'application/x-www-form-urlencoded')
.send({ username: "username", password: "password" })
.end(function(err, res){
console.log(res.text);
});  

How to write a switch statement in Ruby

You can do like this in more natural way,

case expression
when condtion1
   function
when condition2
   function
else
   function
end

Pylint, PyChecker or PyFlakes?

pep8 was recently added to PyPi.

  • pep8 - Python style guide checker
  • pep8 is a tool to check your Python code against some of the style conventions in PEP 8.

It is now super easy to check your code against pep8.

See http://pypi.python.org/pypi/pep8

Check if element is in the list (contains)

Use std::find, something like:

if (std::find(std::begin(my_list), std::end(my_list), my_var) != std::end(my_list))
    // my_list has my_var

How do I use Maven through a proxy?

For details of setting up a proxy for Maven, see the mini guide.

Essentially you need to ensure the proxies section in either the global settings ([maven install]/conf/settings.xml), or user settings (${user.home}/.m2/settings.xml) is configured correctly. It is better to do this in your user settings to avoid storing the password in plain text in a public location.

Maven 2.1 introduced password encryption, but I've not got round to checking if the encryption applies for the proxy settings as well as repository passwords (don't see why it wouldn't though).

For info, there is a commented-out proxy configuration in your settings.xml and instructions on how to modify it.

From the mini-guide, your settings should look something like this:

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                  http://maven.apache.org/xsd/settings-1.0.0.xsd">
[...]
  <proxies>
    <proxy>
      <active>true</active>
      <protocol>http</protocol>
      <host>proxy.somewhere.com</host>
      <port>8080</port>
      <username>proxyuser</username>
      <password>somepassword</password>
      <nonProxyHosts>www.google.com|*.somewhere.com</nonProxyHosts>
    </proxy>
  </proxies>
[...]
</settings>

else & elif statements not working in Python

Python can generate same 'invalid syntax' error even if ident for 'elif' block not matching to 'if' block ident (tabs for the first, spaces for second or vice versa).

How do I check if an object has a key in JavaScript?

You should use hasOwnProperty. For example:

myObj.hasOwnProperty('myKey');

Note: If you are using ESLint, the above may give you an error for violating the no-prototype-builtins rule, in that case the workaround is as below:

Object.prototype.hasOwnProperty.call(myObj, 'myKey');

Random numbers with Math.random() in Java

A better approach is:

int x = rand.nextInt(max - min + 1) + min;

Your formula generates numbers between min and min + max.

Random random = new Random(1234567);
int min = 5;
int max = 20;
while (true) {
    int x = (int)(Math.random() * max) + min;
    System.out.println(x);
    if (x < min || x >= max) { break; }
}       

Result:

10
16
13
21 // Oops!!

See it online here: ideone

Get content uri from file path in android

You can use these two ways based on use

Uri uri = Uri.parse("String file location");

or

Uri uri = Uri.fromFile(new File("string file location"));

I have tried both ways and both works.

Playing HTML5 video on fullscreen in android webview

Cprcrack's answer works very well for API levels 19 and under. Just a minor addition to cprcrack's onShowCustomView will get it working on API level 21+

if (Build.VERSION.SDK_INT >= 21) {
      videoViewContainer.setBackgroundColor(Color.BLACK);
      ((ViewGroup) webView.getParent()).addView(videoViewContainer);
      webView.scrollTo(0,0);  // centers full screen view 
} else {
      activityNonVideoView.setVisibility(View.INVISIBLE);
      ViewGroup.LayoutParams vg = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.MATCH_PARENT);
      activityVideoView.addView(videoViewContainer,vg);
      activityVideoView.setVisibility(View.VISIBLE);
}

You will also need to reflect the changes in onHideCustomView

Set the default value in dropdownlist using jQuery

$('#userZipFiles option').prop('selected', function() {
        return this.defaultSelected;
    });     

QString to char* conversion

Maybe

my_qstring.toStdString().c_str();

or safer, as Federico points out:

std::string str = my_qstring.toStdString();
const char* p = str.c_str();

It's far from optimal, but will do the work.

How to get request url in a jQuery $.get/ajax request

I can't get it to work on $.get() because it has no complete event.

I suggest to use $.ajax() like this,

$.ajax({
    url: 'http://www.example.org',
    data: {'a':1,'b':2,'c':3},
    dataType: 'xml',
    complete : function(){
        alert(this.url)
    },
    success: function(xml){
    }
});

craz demo

proper way to sudo over ssh

Another way is to use the -t switch to ssh:

ssh -t user@server "sudo script"

See man ssh:

 -t      Force pseudo-tty allocation.  This can be used to execute arbi-
         trary screen-based programs on a remote machine, which can be
         very useful, e.g., when implementing menu services.  Multiple -t
         options force tty allocation, even if ssh has no local tty.

How to access local files of the filesystem in the Android emulator?

In addition to the accepted answer, if you are using Android Studio you can

  1. invoke Android Device Monitor,
  2. select the device in the Devices tab on the left,
  3. select File Explorer tab on the right,
  4. navigate to the file you want, and
  5. click the Pull a file from the device button to save it to your local file system

Taken from Working with an emulator or device's file system

What is the difference between XAMPP or WAMP Server & IIS?

WAMP is an acronym for Windows (OS), Apache (web-server), MySQL (database), PHP (language).

XAMPP and WampServer are both free packages of WAMP, with additional applications/tools, put together by different people. There are also other WAMPs such as UniformServer. And there are commercial WAMPs such as WampDeveloper (what I use).

Their differences are in the format/structure of the package, the configurations, and the included management applications.

IIS is a web-server application just like Apache is, except it's made by Microsoft and is Windows only (Apache runs on both Windows and Linux). IIS is also more geared towards using ASP.NET (vs. PHP) and "SQL Server" (vs. MySQL), though it can use PHP and MySQL too.

Escape invalid XML characters in C#

As the way to remove invalid XML characters I suggest you to use XmlConvert.IsXmlChar method. It was added since .NET Framework 4 and is presented in Silverlight too. Here is the small sample:

void Main() {
    string content = "\v\f\0";
    Console.WriteLine(IsValidXmlString(content)); // False

    content = RemoveInvalidXmlChars(content);
    Console.WriteLine(IsValidXmlString(content)); // True
}

static string RemoveInvalidXmlChars(string text) {
    var validXmlChars = text.Where(ch => XmlConvert.IsXmlChar(ch)).ToArray();
    return new string(validXmlChars);
}

static bool IsValidXmlString(string text) {
    try {
        XmlConvert.VerifyXmlChars(text);
        return true;
    } catch {
        return false;
    }
}

And as the way to escape invalid XML characters I suggest you to use XmlConvert.EncodeName method. Here is the small sample:

void Main() {
    const string content = "\v\f\0";
    Console.WriteLine(IsValidXmlString(content)); // False

    string encoded = XmlConvert.EncodeName(content);
    Console.WriteLine(IsValidXmlString(encoded)); // True

    string decoded = XmlConvert.DecodeName(encoded);
    Console.WriteLine(content == decoded); // True
}

static bool IsValidXmlString(string text) {
    try {
        XmlConvert.VerifyXmlChars(text);
        return true;
    } catch {
        return false;
    }
}

Update: It should be mentioned that the encoding operation produces a string with a length which is greater or equal than a length of a source string. It might be important when you store a encoded string in a database in a string column with length limitation and validate source string length in your app to fit data column limitation.

How can I change the version of npm using nvm?

Changing npm versions on linux based OSs isn't a straight forward one command process yet. I have done following to switch back to older version of npm. This should work to get any version of npm working. First install the version of npm you want to use:

sudo npm install -g [email protected]

Remove the sym link in /usr/local/bin/

sudo rm /usr/local/bin/npm

Recreate the sym link using the desired version of npm you have installed

sudo ln -s /usr/bin/[email protected] /usr/local/bin/npm

Show pop-ups the most elegant way

  • Create a 'popup' directive and apply it to the container of the popup content
  • In the directive, wrap the content in a absolute position div along with the mask div below it.
  • It is OK to move the 2 divs in the DOM tree as needed from within the directive. Any UI code is OK in the directives, including the code to position the popup in center of screen.
  • Create and bind a boolean flag to controller. This flag will control visibility.
  • Create scope variables that bond to OK / Cancel functions etc.

Editing to add a high level example (non functional)

<div id='popup1-content' popup='showPopup1'>
  ....
  ....
</div>


<div id='popup2-content' popup='showPopup2'>
  ....
  ....
</div>



.directive('popup', function() {
  var p = {
      link : function(scope, iElement, iAttrs){
           //code to wrap the div (iElement) with a abs pos div (parentDiv)
          // code to add a mask layer div behind 
          // if the parent is already there, then skip adding it again.
         //use jquery ui to make it dragable etc.
          scope.watch(showPopup, function(newVal, oldVal){
               if(newVal === true){
                   $(parentDiv).show();
                 } 
              else{
                 $(parentDiv).hide();
                }
          });
      }


   }
  return p;
});

jQuery move to anchor location on page load

Description

You can do this using jQuery's .scrollTop() and .offset() method

Check out my sample and this jsFiddle Demonstration

Sample

$(function() {
    $(document).scrollTop( $("#header").offset().top );  
});

More Information

Import Package Error - Cannot Convert between Unicode and Non Unicode String Data Type

Two solutions: 1- if the type of the target column is [nvarchar] it should be change to [varchar]

2- Add a "Derived Column" component to the SSIS package and add a new column with the following expression:
(DT_WSTR, «length») [ColumnName]

Length is the length of the column in the target table and ColumnName is the name of the column in the target table. finally at the mapping part you should use this new added column instead of the original column.

How to change language of app when user selects language?

    Locale locale = new Locale(langCode);
    Locale.setDefault(locale);
    Configuration configuration = context.getResources().getConfiguration();
    configuration.locale = locale;
    preferences.setLocalePref(langCode);
    context.getResources().updateConfiguration(configuration, context.getResources().getDisplayMetrics());

Here, langCode is the required language code. You can save the language code as string in sharedPreferences. and you can call this code super.onCreate(savedInstanceState) in onCreate.

How to get all checked checkboxes

In IE9+, Chrome or Firefox you can do:

var checkedBoxes = document.querySelectorAll('input[name=mycheckboxes]:checked');

Pandas: drop a level from a multi-level column index?

You can use MultiIndex.droplevel:

>>> cols = pd.MultiIndex.from_tuples([("a", "b"), ("a", "c")])
>>> df = pd.DataFrame([[1,2], [3,4]], columns=cols)
>>> df
   a   
   b  c
0  1  2
1  3  4

[2 rows x 2 columns]
>>> df.columns = df.columns.droplevel()
>>> df
   b  c
0  1  2
1  3  4

[2 rows x 2 columns]