Programs & Examples On #Muxer

An explicit value for the identity column in table can only be specified when a column list is used and IDENTITY_INSERT is ON SQL Server

Both will work but if you still get error by using #1 then go for #2

1)

SET IDENTITY_INSERT customers ON
GO
insert into dbo.tbl_A_archive(id, ...)
SELECT Id, ...
FROM SERVER0031.DB.dbo.tbl_A

2)

SET IDENTITY_INSERT customers ON
GO
insert into dbo.tbl_A_archive(id, ...)
VALUES(@Id,....)

Datatables - Search Box outside datatable

I had the same problem.

I tried all alternatives posted, but no work, I used a way that is not right but it worked perfectly.

Example search input

<input id="searchInput" type="text"> 

the jquery code

$('#listingData').dataTable({
  responsive: true,
  "bFilter": true // show search input
});
$("#listingData_filter").addClass("hidden"); // hidden search input

$("#searchInput").on("input", function (e) {
   e.preventDefault();
   $('#listingData').DataTable().search($(this).val()).draw();
});

How should I use Outlook to send code snippets?

Would sending the mail as plain-text sort this?

"How to Send a Plain Text Message in Outlook":

  • Select Actions | New Mail Message Using | Plain Text from the menu in Outlook.
  • Create your message as usual.
  • Click Send to deliver it.

Being plain text it shouldn't screw up your code, with "smart" quotes, auto-capitalisation and such.

Another possible option, if this is a common problem within the company perhaps you could setup an internal code-paste site, there's plenty of open-source ones around, like Open Pastebin

importing external ".txt" file in python

The "import" keyword is for attaching python definitions that are created external to the current python program. So in your case, where you just want to read a file with some text in it, use:

text = open("words.txt", "rb").read()

J2ME/Android/BlackBerry - driving directions, route between two locations

J2ME Map Route Provider

maps.google.com has a navigation service which can provide you route information in KML format.

To get kml file we need to form url with start and destination locations:

public static String getUrl(double fromLat, double fromLon,
                            double toLat, double toLon) {// connect to map web service
    StringBuffer urlString = new StringBuffer();
    urlString.append("http://maps.google.com/maps?f=d&hl=en");
    urlString.append("&saddr=");// from
    urlString.append(Double.toString(fromLat));
    urlString.append(",");
    urlString.append(Double.toString(fromLon));
    urlString.append("&daddr=");// to
    urlString.append(Double.toString(toLat));
    urlString.append(",");
    urlString.append(Double.toString(toLon));
    urlString.append("&ie=UTF8&0&om=0&output=kml");
    return urlString.toString();
}

Next you will need to parse xml (implemented with SAXParser) and fill data structures:

public class Point {
    String mName;
    String mDescription;
    String mIconUrl;
    double mLatitude;
    double mLongitude;
}

public class Road {
    public String mName;
    public String mDescription;
    public int mColor;
    public int mWidth;
    public double[][] mRoute = new double[][] {};
    public Point[] mPoints = new Point[] {};
}

Network connection is implemented in different ways on Android and Blackberry, so you will have to first form url:

 public static String getUrl(double fromLat, double fromLon,
     double toLat, double toLon)

then create connection with this url and get InputStream.
Then pass this InputStream and get parsed data structure:

 public static Road getRoute(InputStream is) 

Full source code RoadProvider.java

BlackBerry

class MapPathScreen extends MainScreen {
    MapControl map;
    Road mRoad = new Road();
    public MapPathScreen() {
        double fromLat = 49.85, fromLon = 24.016667;
        double toLat = 50.45, toLon = 30.523333;
        String url = RoadProvider.getUrl(fromLat, fromLon, toLat, toLon);
        InputStream is = getConnection(url);
        mRoad = RoadProvider.getRoute(is);
        map = new MapControl();
        add(new LabelField(mRoad.mName));
        add(new LabelField(mRoad.mDescription));
        add(map);
    }
    protected void onUiEngineAttached(boolean attached) {
        super.onUiEngineAttached(attached);
        if (attached) {
            map.drawPath(mRoad);
        }
    }
    private InputStream getConnection(String url) {
        HttpConnection urlConnection = null;
        InputStream is = null;
        try {
            urlConnection = (HttpConnection) Connector.open(url);
            urlConnection.setRequestMethod("GET");
            is = urlConnection.openInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
}

See full code on J2MEMapRouteBlackBerryEx on Google Code

Android

Android G1 screenshot

public class MapRouteActivity extends MapActivity {
    LinearLayout linearLayout;
    MapView mapView;
    private Road mRoad;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        new Thread() {
            @Override
            public void run() {
                double fromLat = 49.85, fromLon = 24.016667;
                double toLat = 50.45, toLon = 30.523333;
                String url = RoadProvider
                        .getUrl(fromLat, fromLon, toLat, toLon);
                InputStream is = getConnection(url);
                mRoad = RoadProvider.getRoute(is);
                mHandler.sendEmptyMessage(0);
            }
        }.start();
    }

    Handler mHandler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            TextView textView = (TextView) findViewById(R.id.description);
            textView.setText(mRoad.mName + " " + mRoad.mDescription);
            MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
            mapView.invalidate();
        };
    };

    private InputStream getConnection(String url) {
        InputStream is = null;
        try {
            URLConnection conn = new URL(url).openConnection();
            is = conn.getInputStream();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}

See full code on J2MEMapRouteAndroidEx on Google Code

How do I call a dynamically-named method in Javascript?

Within a ServiceWorker or Worker, replace window with self:

self[method_prefix + method_name](arg1, arg2);

Workers have no access to the DOM, therefore window is an invalid reference. The equivalent global scope identifier for this purpose is self.

Proper way to exit iPhone application?

This has gotten a good answer but decided to expand a bit:

You can't get your application accepted to AppStore without reading Apple's iOS Human Interface Guidelines well. (they retain the right to reject you for doing anything against them) The section "Don't Quit Programmatically" http://developer.apple.com/library/ios/#DOCUMENTATION/UserExperience/Conceptual/MobileHIG/UEBestPractices/UEBestPractices.html is an exact guideline in how you should treat in this case.

If you ever have a problem with Apple platform you can't easily find a solution for, consult HIG. It's possible Apple simply doesn't want you to do it and they usually (I'm not Apple so I can't guarantee always) do say so in their documentation.

What is an 'undeclared identifier' error and how do I fix it?

Most of the time, if you are very sure you imported the library in question, Visual Studio will guide you with IntelliSense.

Here is what worked for me:

Make sure that #include "stdafx.h" is declared first, that is, at the top of all of your includes.

Call-time pass-by-reference has been removed

Only call time pass-by-reference is removed. So change:

call_user_func($func, &$this, &$client ...

To this:

call_user_func($func, $this, $client ...

&$this should never be needed after PHP4 anyway period.

If you absolutely need $client to be passed by reference, update the function ($func) signature instead (function func(&$client) {)

How to change column datatype from character to numeric in PostgreSQL 8.4

You can try using USING:

The optional USING clause specifies how to compute the new column value from the old; if omitted, the default conversion is the same as an assignment cast from old data type to new. A USING clause must be provided if there is no implicit or assignment cast from old to new type.

So this might work (depending on your data):

alter table presales alter column code type numeric(10,0) using code::numeric;
-- Or if you prefer standard casting...
alter table presales alter column code type numeric(10,0) using cast(code as numeric);

This will fail if you have anything in code that cannot be cast to numeric; if the USING fails, you'll have to clean up the non-numeric data by hand before changing the column type.

How to change Apache Tomcat web server port number

Simple !!... you can do it easily via server.xml

  • Go to tomcat>conf folder
  • Edit server.xml
  • Search "Connector port"
  • Replace "8080" by your port number
  • Restart tomcat server.

You are done!.

Gulp error: The following tasks did not complete: Did you forget to signal async completion?

Basically v3.X was simpler but v4.x is strict in these means of synchronous & asynchronous tasks.

The async/await is pretty simple & helpful way to understand the workflow & issue.

Use this simple approach

const gulp = require('gulp')

gulp.task('message',async function(){
return console.log('Gulp is running...')
})

New lines inside paragraph in README.md

According to Github API two empty lines are a new paragraph (same as here in stackoverflow)

You can test it with http://prose.io

SQL Server Group By Month

Another approach, that doesn't involve adding columns to the result, is to simply zero-out the day component of the date, so 2016-07-13 and 2016-07-16 would both be 2016-07-01 - thus making them equal by month.

If you have a date (not a datetime) value, then you can zero it directly:

SELECT
    DATEADD( day, 1 - DATEPART( day, [Date] ), [Date] ),
    COUNT(*)
FROM
    [Table]
GROUP BY
    DATEADD( day, 1 - DATEPART( day, [Date] ), [Date] )

If you have datetime values, you'll need to use CONVERT to remove the time-of-day portion:

SELECT
    DATEADD( day, 1 - DATEPART( day, [Date] ),  CONVERT( date, [Date] ) ),
    COUNT(*)
FROM
    [Table]
GROUP BY
    DATEADD( day, 1 - DATEPART( day, [Date] ),  CONVERT( date, [Date] ) )

Resource u'tokenizers/punkt/english.pickle' not found

For me nothing of the above worked, so I just downloaded all the files by hand from the web site http://www.nltk.org/nltk_data/ and I put them also by hand in a file "tokenizers" inside of "nltk_data" folder. Not a pretty solution but still a solution.

How to add font-awesome to Angular 2 + CLI project

In Angular 11

npm install @fortawesome/angular-fontawesome --save
npm install @fortawesome/fontawesome-svg-core --save
npm install @fortawesome/free-solid-svg-icons --save

And then in app.module.ts at imports array

import { FontAwesomeModule } from '@fortawesome/angular-fontawesome';

  imports: [
    BrowserModule,
    FontAwesomeModule
  ],

And then in any.component.ts

turningGearIcon = faCogs;

And then any.component.html

<fa-icon [icon]="turningGearIcon"></fa-icon>

How to rename uploaded file before saving it into a directory?

You can simply change the name of the file by changing the name of the file in the second parameter of move_uploaded_file.

Instead of

move_uploaded_file($_FILES["file"]["tmp_name"], "../img/imageDirectory/" . $_FILES["file"]["name"]);

Use

$temp = explode(".", $_FILES["file"]["name"]);
$newfilename = round(microtime(true)) . '.' . end($temp);
move_uploaded_file($_FILES["file"]["tmp_name"], "../img/imageDirectory/" . $newfilename);

Changed to reflect your question, will product a random number based on the current time and append the extension from the originally uploaded file.

How to tell if JRE or JDK is installed

You can open up terminal and simply type

java -version // this will check your jre version
javac -version // this will check your java compiler version if you installed 

this should show you the version of java installed on the system (assuming that you have set the path of the java in system environment).

And if you haven't, add it via

export JAVA_HOME=/path/to/java/jdk1.x

and if you unsure if you have java at all on your system just use find in terminal

i.e. find / -name "java"

How to bind WPF button to a command in ViewModelBase?

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

the code behind for the window:

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

The ViewModel:

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

    public void MyAction()
    {

    }
}

Command Handler:

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

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

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

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

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

I hope this will give you the idea.

How do you set the document title in React?

Since React 16.8. you can build a custom hook to do so (similar to the solution of @Shortchange):

export function useTitle(title) {
  useEffect(() => {
    const prevTitle = document.title
    document.title = title
    return () => {
      document.title = prevTitle
    }
  })
}

this can be used in any react component, e.g.:

const MyComponent = () => {
  useTitle("New Title")
  return (
    <div>
     ...
    </div>
  )
}

It will update the title as soon as the component mounts and reverts it to the previous title when it unmounts.

How to write URLs in Latex?

Here is all the information you need in order to format clickable hyperlinks in LaTeX:

http://en.wikibooks.org/wiki/LaTeX/Hyperlinks

Essentially, you use the hyperref package and use the \url or \href tag depending on what you're trying to achieve.

How to generate auto increment field in select query

In the case you have no natural partition value and just want an ordered number regardless of the partition you can just do a row_number over a constant, in the following example i've just used 'X'. Hope this helps someone

select 
    ROW_NUMBER() OVER(PARTITION BY num ORDER BY col1) as aliascol1, 
    period_next_id, period_name_long
from 
(
  select distinct col1, period_name_long, 'X' as num
  from {TABLE} 
) as x

How to indent HTML tags in Notepad++

Use the XML Tools plugin for Notepad++ and then you can Auto-Indent the code with Ctrl+Alt+Shift+B .For the more point-and-click inclined, you could also go to Plugins --> XML Tools --> Pretty Print.

How do I get today's date in C# in mm/dd/yyyy format?

DateTime.Now.Date.ToShortDateString()

is culture specific.

It is best to stick with:

DateTime.Now.ToString("d/MM/yyyy");

Why use getters and setters/accessors?

It can be useful for lazy-loading. Say the object in question is stored in a database, and you don't want to go get it unless you need it. If the object is retrieved by a getter, then the internal object can be null until somebody asks for it, then you can go get it on the first call to the getter.

I had a base page class in a project that was handed to me that was loading some data from a couple different web service calls, but the data in those web service calls wasn't always used in all child pages. Web services, for all of the benefits, pioneer new definitions of "slow", so you don't want to make a web service call if you don't have to.

I moved from public fields to getters, and now the getters check the cache, and if it's not there call the web service. So with a little wrapping, a lot of web service calls were prevented.

So the getter saves me from trying to figure out, on each child page, what I will need. If I need it, I call the getter, and it goes to find it for me if I don't already have it.

    protected YourType _yourName = null;
    public YourType YourName{
      get
      {
        if (_yourName == null)
        {
          _yourName = new YourType();
          return _yourName;
        }
      }
    }

With MySQL, how can I generate a column containing the record index in a table?

SELECT @i:=@i+1 AS iterator, t.*
FROM tablename t,(SELECT @i:=0) foo

How to pass a Javascript Array via JQuery Post so that all its contents are accessible via the PHP $_POST array?

If you want to pass a JavaScript object/hash (ie. an associative array in PHP) then you would do:

$.post('/url/to/page', {'key1': 'value', 'key2': 'value'});

If you wanna pass an actual array (ie. an indexed array in PHP) then you can do:

$.post('/url/to/page', {'someKeyName': ['value','value']});

If you want to pass a JavaScript array then you can do:

$.post('/url/to/page', {'someKeyName': variableName});

Equivalent of LIMIT for DB2

Developed this method:

You NEED a table that has an unique value that can be ordered.

If you want rows 10,000 to 25,000 and your Table has 40,000 rows, first you need to get the starting point and total rows:

int start = 40000 - 10000;

int total = 25000 - 10000;

And then pass these by code to the query:

SELECT * FROM 
(SELECT * FROM schema.mytable 
ORDER BY userId DESC fetch first {start} rows only ) AS mini 
ORDER BY mini.userId ASC fetch first {total} rows only

How to extract public key using OpenSSL?

Though, the above technique works for the general case, it didn't work on Amazon Web Services (AWS) PEM files.

I did find in the AWS docs the following command works: ssh-keygen -y

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html

edit Thanks @makenova for the complete line:

ssh-keygen -y -f key.pem > key.pub

java.io.StreamCorruptedException: invalid stream header: 54657374

Clearly you aren't sending the data with ObjectOutputStream: you are just writing the bytes.

  • If you read with readObject() you must write with writeObject().
  • If you read with readUTF() you must write with writeUTF().
  • If you read with readXXX() you must write with writeXXX(), for most values of XXX.

How to pass parameters to the DbContext.Database.ExecuteSqlCommand method?

public static class DbEx {
    public static IEnumerable<T> SqlQueryPrm<T>(this System.Data.Entity.Database database, string sql, object parameters) {
        using (var tmp_cmd = database.Connection.CreateCommand()) {
            var dict = ToDictionary(parameters);
            int i = 0;
            var arr = new object[dict.Count];
            foreach (var one_kvp in dict) {
                var param = tmp_cmd.CreateParameter();
                param.ParameterName = one_kvp.Key;
                if (one_kvp.Value == null) {
                    param.Value = DBNull.Value;
                } else {
                    param.Value = one_kvp.Value;
                }
                arr[i] = param;
                i++;
            }
            return database.SqlQuery<T>(sql, arr);
        }
    }
    private static IDictionary<string, object> ToDictionary(object data) {
        var attr = System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance;
        var dict = new Dictionary<string, object>();
        foreach (var property in data.GetType().GetProperties(attr)) {
            if (property.CanRead) {
                dict.Add(property.Name, property.GetValue(data, null));
            }
        }
        return dict;
    }
}

Usage:

var names = db.Database.SqlQueryPrm<string>("select name from position_category where id_key=@id_key", new { id_key = "mgr" }).ToList();

How to initialize/instantiate a custom UIView class with a XIB file in Swift

As of Swift 2.0, you can add a protocol extension. In my opinion, this is a better approach because the return type is Self rather than UIView, so the caller doesn't need to cast to the view class.

import UIKit

protocol UIViewLoading {}
extension UIView : UIViewLoading {}

extension UIViewLoading where Self : UIView {

  // note that this method returns an instance of type `Self`, rather than UIView
  static func loadFromNib() -> Self {
    let nibName = "\(self)".characters.split{$0 == "."}.map(String.init).last!
    let nib = UINib(nibName: nibName, bundle: nil)
    return nib.instantiateWithOwner(self, options: nil).first as! Self
  }

}

Error: cannot open display: localhost:0.0 - trying to open Firefox from CentOS 6.2 64bit and display on Win7

So, it turns out that X11 wasn't actually installed on the centOS. There didn't seem to be any indication anywhere of it not being installed. I did the following command and now firefox opens:

yum groupinstall 'X Window System' 

Hope this answer will help others that are confused :)

Start thread with member function

Here is a complete example

#include <thread>
#include <iostream>

class Wrapper {
   public:
      void member1() {
          std::cout << "i am member1" << std::endl;
      }
      void member2(const char *arg1, unsigned arg2) {
          std::cout << "i am member2 and my first arg is (" << arg1 << ") and second arg is (" << arg2 << ")" << std::endl;
      }
      std::thread member1Thread() {
          return std::thread([=] { member1(); });
      }
      std::thread member2Thread(const char *arg1, unsigned arg2) {
          return std::thread([=] { member2(arg1, arg2); });
      }
};
int main(int argc, char **argv) {
   Wrapper *w = new Wrapper();
   std::thread tw1 = w->member1Thread();
   std::thread tw2 = w->member2Thread("hello", 100);
   tw1.join();
   tw2.join();
   return 0;
}

Compiling with g++ produces the following result

g++ -Wall -std=c++11 hello.cc -o hello -pthread

i am member1
i am member2 and my first arg is (hello) and second arg is (100)

No provider for HttpClient

I got this error after injecting a Service which used HTTPClient into a class. The class was again used in the service, so it created a circular dependency. I could compile the app with warnings, but in browser console the error occurred

"No provider for HttpClient! (MyService -> HttpClient)"

and it broke the app.

This works:

import { HttpClient, HttpClientModule, HttpHeaders } from '@angular/common/http';
import { MyClass } from "../classes/my.class";

@Injectable()
export class MyService {
  constructor(
    private http: HttpClient
  ){
    // do something with myClass Instances
  }      
}
.
.
.
export class MenuItem {
  constructor(

  ){}
}

This breaks the app

import { HttpClient, HttpClientModule, HttpHeaders } from '@angular/common/http';
import { MyClass } from "../classes/my.class";

@Injectable()
export class MyService {
  constructor(
    private http: HttpClient
  ){
    // do something with myClass Instances
  }      
}
.
.
.
import { MyService } from '../services/my.service';
export class MyClass {
  constructor(
    let injector = ReflectiveInjector.resolveAndCreate([MyService]);
    this.myService = injector.get(MyService);
  ){}
}

After injecting MyService in MyClass I got the circular dependency warning. CLI compiled anyway with this warning but the app did not work anymore and the error was given in browser console. So in my case it didn't had to do anything with @NgModule but with circular dependencies. I recommend to solve the case sensitive naming warnings if your problem still exist.

Convert double/float to string

See if the BSD C Standard Library has fcvt(). You could start with the source for it that rather than writing your code from scratch. The UNIX 98 standard fcvt() apparently does not output scientific notation so you would have to implement it yourself, but I don't think it would be hard.

Escaping ampersand in URL

They need to be percent-encoded:

> encodeURIComponent('&')
"%26"

So in your case, the URL would look like:

http://www.mysite.com?candy_name=M%26M

mysql is not recognised as an internal or external command,operable program or batch

I am using xampp. For me best option is to change environment variables. Environment variable changing window is shared by @Abu Bakr in this thread

I change the path value as C:\xampp\mysql\bin; and it is working nice

Artisan, creating tables in database

in laravel 5 first we need to create migration and then run the migration

Step 1.

php artisan make:migration create_users_table --create=users

Step 2.

php artisan migrate

What does ||= (or-equals) mean in Ruby?

If X does NOT have a value, it will be assigned the value of Y. Else, it will preserve it's original value, 5 in this example:

irb(main):020:0> x = 5
=> 5
irb(main):021:0> y = 10
=> 10
irb(main):022:0> x ||= y
=> 5

# Now set x to nil. 

irb(main):025:0> x = nil
=> nil
irb(main):026:0> x ||= y
=> 10

how do I create an array in jquery?

You may be confusing Javascript arrays with PHP arrays. In PHP, arrays are very flexible. They can either be numerically indexed or associative, or even mixed.

array('Item 1', 'Item 2', 'Items 3')  // numerically indexed array
array('first' => 'Item 1', 'second' => 'Item 2')  // associative array
array('first' => 'Item 1', 'Item 2', 'third' => 'Item 3')

Other languages consider these two to be different things, Javascript being among them. An array in Javascript is always numerically indexed:

['Item 1', 'Item 2', 'Item 3']  // array (numerically indexed)

An "associative array", also called Hash or Map, technically an Object in Javascript*, works like this:

{ first : 'Item 1', second : 'Item 2' }  // object (a.k.a. "associative array")

They're not interchangeable. If you need "array keys", you need to use an object. If you don't, you make an array.


* Technically everything is an Object in Javascript, please put that aside for this argument. ;)

Excel formula to remove space between words in a cell

Suppose the data is in the B column, write in the C column the formula:

=SUBSTITUTE(B1," ","")

Copy&Paste the formula in the whole C column.

edit: using commas or semicolons as parameters separator depends on your regional settings (I have to use the semicolons). This is weird I think. Thanks to @tocallaghan and @pablete for pointing this out.

Size of character ('a') in C/C++

In C, the type of a character constant like 'a' is actually an int, with size of 4 (or some other implementation-dependent value). In C++, the type is char, with size of 1. This is one of many small differences between the two languages.

Failed to resolve: com.android.support:appcompat-v7:28.0

Run

gradlew -q app:dependencies

It will remove what is wrong.

How do I fetch lines before/after the grep result in bash?

You can use the -B and -A to print lines before and after the match.

grep -i -B 10 'error' data

Will print the 10 lines before the match, including the matching line itself.

Switching to landscape mode in Android Emulator

In my windows-8 laptop, ctrl + fn + F11 works.

How to create global variables accessible in all views using Express / Node.JS?

After having a chance to study the Express 3 API Reference a bit more I discovered what I was looking for. Specifically the entries for app.locals and then a bit farther down res.locals held the answers I needed.

I discovered for myself that the function app.locals takes an object and stores all of its properties as global variables scoped to the application. These globals are passed as local variables to each view. The function res.locals, however, is scoped to the request and thus, response local variables are accessible only to the view(s) rendered during that particular request/response.

So for my case in my app.js what I did was add:

app.locals({
    site: {
        title: 'ExpressBootstrapEJS',
        description: 'A boilerplate for a simple web application with a Node.JS and Express backend, with an EJS template with using Twitter Bootstrap.'
    },
    author: {
        name: 'Cory Gross',
        contact: '[email protected]'
    }
});

Then all of these variables are accessible in my views as site.title, site.description, author.name, author.contact.

I could also define local variables for each response to a request with res.locals, or simply pass variables like the page's title in as the optionsparameter in the render call.

EDIT: This method will not allow you to use these locals in your middleware. I actually did run into this as Pickels suggests in the comment below. In this case you will need to create a middleware function as such in his alternative (and appreciated) answer. Your middleware function will need to add them to res.locals for each response and then call next. This middleware function will need to be placed above any other middleware which needs to use these locals.

EDIT: Another difference between declaring locals via app.locals and res.locals is that with app.locals the variables are set a single time and persist throughout the life of the application. When you set locals with res.locals in your middleware, these are set everytime you get a request. You should basically prefer setting globals via app.locals unless the value depends on the request req variable passed into the middleware. If the value doesn't change then it will be more efficient for it to be set just once in app.locals.

How to auto adjust the div size for all mobile / tablet display formats?

I use something like this in my document.ready

var height = $(window).height();//gets height from device
var width = $(window).width(); //gets width from device

$("#container").width(width+"px");
$("#container").height(height+"px");

Regular Expression usage with ls

You don't say what shell you are using, but they generally don't support regular expressions that way, although there are common *nix CLI tools (grep, sed, etc) that do.

What shells like bash do support is globbing, which uses some similiar characters (eg, *) but is not the same thing.

Newer versions of bash do have a regular expression operator, =~:

for x in `ls`; do 
    if [[ $x =~ .+\..* ]]; then 
        echo $x; 
    fi; 
done

Convert object to JSON in Android

Might be better choice:

@Override
public String toString() {
    return new GsonBuilder().create().toJson(this, Producto.class);
}

Bundling data files with PyInstaller (--onefile)

pyinstaller unpacks your data into a temporary folder, and stores this directory path in the _MEIPASS2 environment variable. To get the _MEIPASS2 dir in packed-mode and use the local directory in unpacked (development) mode, I use this:

def resource_path(relative):
    return os.path.join(
        os.environ.get(
            "_MEIPASS2",
            os.path.abspath(".")
        ),
        relative
    )

Output:

# in development
>>> resource_path("app_icon.ico")
"/home/shish/src/my_app/app_icon.ico"

# in production
>>> resource_path("app_icon.ico")
"/tmp/_MEI34121/app_icon.ico"

How to increase memory limit for PHP over 2GB?

For others who are experiencing with the same problem, here is the description of the bug in php + patch https://bugs.php.net/bug.php?id=44522

Add to integers in a list

If you try appending the number like, say listName.append(4) , this will append 4 at last. But if you are trying to take <int> and then append it as, num = 4 followed by listName.append(num), this will give you an error as 'num' is of <int> type and listName is of type <list>. So do type cast int(num) before appending it.

What is the right way to debug in iPython notebook?

Just type import pdb in jupyter notebook, and then use this cheatsheet to debug. It's very convenient.

c --> continue, s --> step, b 12 --> set break point at line 12 and so on.

Some useful links: Python Official Document on pdb, Python pdb debugger examples for better understanding how to use the debugger commands.

Some useful screenshots: enter image description hereenter image description here

Enable remote connections for SQL Server Express 2012

This article helped me...

How to enable remote connections in SQL Server

Everything in SQL Server was configured, my issue was the firewall was blocking port 1433

Change the "From:" address in Unix "mail"

I don't know if it's the same with other OS, but in OpenBSD, the mail command has this syntax:

mail to-addr ... -sendmail-options ...

sendmail has -f option where you indicate the email address for the FROM: field. The following command works for me.

mail [email protected] -f [email protected]

How to implement drop down list in flutter?

For anyone interested to implement a DropDown of custom class you can follow the bellow steps.

  1. Suppose you have a class called Language with the following code and a static method which returns a List<Language>

    class Language {
      final int id;
      final String name;
      final String languageCode;
    
      const Language(this.id, this.name, this.languageCode);
    
    
    }
    
     const List<Language> getLanguages = <Language>[
            Language(1, 'English', 'en'),
            Language(2, '?????', 'fa'),
            Language(3, '????', 'ps'),
         ];
    
  2. Anywhere you want to implement a DropDown you can import the Language class first use it as follow

        DropdownButton(
            underline: SizedBox(),
            icon: Icon(
                        Icons.language,
                        color: Colors.white,
                        ),
            items: getLanguages.map((Language lang) {
            return new DropdownMenuItem<String>(
                            value: lang.languageCode,
                            child: new Text(lang.name),
                          );
                        }).toList(),
    
            onChanged: (val) {
                          print(val);
                       },
          )
    

How does one reorder columns in a data frame?

The only one I have seen work well is from here.

 shuffle_columns <- function (invec, movecommand) {
      movecommand <- lapply(strsplit(strsplit(movecommand, ";")[[1]],
                                 ",|\\s+"), function(x) x[x != ""])
  movelist <- lapply(movecommand, function(x) {
    Where <- x[which(x %in% c("before", "after", "first",
                              "last")):length(x)]
    ToMove <- setdiff(x, Where)
    list(ToMove, Where)
  })
  myVec <- invec
  for (i in seq_along(movelist)) {
    temp <- setdiff(myVec, movelist[[i]][[1]])
    A <- movelist[[i]][[2]][1]
    if (A %in% c("before", "after")) {
      ba <- movelist[[i]][[2]][2]
      if (A == "before") {
        after <- match(ba, temp) - 1
      }
      else if (A == "after") {
        after <- match(ba, temp)
      }
    }
    else if (A == "first") {
      after <- 0
    }
    else if (A == "last") {
      after <- length(myVec)
    }
    myVec <- append(temp, values = movelist[[i]][[1]], after = after)
  }
  myVec
}

Use like this:

new_df <- iris[shuffle_columns(names(iris), "Sepal.Width before Sepal.Length")]

Works like a charm.

How do you programmatically set an attribute?

Also works fine within a class:

def update_property(self, property, value):
   setattr(self, property, value)

MySQL foreach alternative for procedure

This can be done with MySQL, although it's highly unintuitive:

CREATE PROCEDURE p25 (OUT return_val INT)
BEGIN
  DECLARE a,b INT;
  DECLARE cur_1 CURSOR FOR SELECT s1 FROM t;
  DECLARE CONTINUE HANDLER FOR NOT FOUND
  SET b = 1;
  OPEN cur_1;
  REPEAT
    FETCH cur_1 INTO a;
    UNTIL b = 1
  END REPEAT;
  CLOSE cur_1;
  SET return_val = a;
END;//

Check out this guide: mysql-storedprocedures.pdf

Oracle get previous day records

Im a bit confused about this part "TO_DATE(TO_CHAR(CURRENT_DATE, 'YYYY-MM-DD'),'YYYY-MM-DD')". What were you trying to do with this clause ? The format that you are displaying in your result is the default format when you run the basic query of getting date from DUAL. Other than that, i did this in your query and it retrieved the previous day 'SELECT (CURRENT_DATE - 1) FROM Dual'. Do let me know if it works out for you and if not then do tell me about the problem. Thanks and all the best.

How to go to each directory and execute a command?

You can do the following, when your current directory is parent_directory:

for d in [0-9][0-9][0-9]
do
    ( cd "$d" && your-command-here )
done

The ( and ) create a subshell, so the current directory isn't changed in the main script.

Spring Boot @autowired does not work, classes in different package

Another fun way you can screw this up is annotating a setter method's parameter. It appears that for setter methods (unlike constructors), you have to annotate the method as a whole.

This does not work for me: public void setRepository(@Autowired WidgetRepository repo)

but this does: @Autowired public void setRepository(WidgetRepository repo)

(Spring Boot 2.3.2)

Why does Eclipse automatically add appcompat v7 library support whenever I create a new project?

Sorry with my English, When you create a new android project, you should choose api of high level, for example: from api 17 to api 21, It will not have appcompat and very easy to share project. If you did it with lower API, you just edit in Android Manifest to have upper API :), after that, you can delete Appcompat V7.

How to change the text on the action bar

getSupportActionBar().setTitle("title");

Swift: Sort array of objects alphabetically

Most of these answers are wrong due to the failure to use a locale based comparison for sorting. Look at localizedStandardCompare()

Disable browser's back button

Instead of trying to disable the browser back button it's better to support it. .NET 3.5 can very well handle the browser back (and forward) buttons. Search with Google: "Scriptmanager EnableHistory". You can control which user actions will add an entry to the browser's history (ScriptManager -> AddHistoryPoint) and your ASP.NET application receives an event whenever the user clicks the browser Back/Forward buttons. This will work for all known browsers

Best way to create unique token in Rails?

I think token should be handled just like password. As such, they should be encrypted in DB.

I'n doing something like this to generate a unique new token for a model:

key = ActiveSupport::KeyGenerator
                .new(Devise.secret_key)
                .generate_key("put some random or the name of the key")

loop do
  raw = SecureRandom.urlsafe_base64(nil, false)
  enc = OpenSSL::HMAC.hexdigest('SHA256', key, raw)

  break [raw, enc] unless Model.exist?(token: enc)
end

Move view with keyboard using Swift

Swift 4.1

 override func viewDidLoad() {
    super.viewDidLoad()            
    NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)    
}

@objc func keyboardWillShow(notification: NSNotification) {        
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y == 0 {
            self.view.frame.origin.y -= keyboardSize.height   //can adjust as keyboardSize.height-(any number 30 or 40)
        }
    }        
}

@objc func keyboardWillHide(notification: NSNotification) {
    if self.view.frame.origin.y != 0 {
        self.view.frame.origin.y = 0
    }
}

"Uncaught SyntaxError: Cannot use import statement outside a module" when importing ECMAScript 6

For me, it was caused before I referred a library (specifically typeORM, using the ormconfig.js file, under the entities key) to the src folder, instead of the dist folder...

   "entities": [
      "src/db/entity/**/*.ts", // Pay attention to "src" and "ts" (this is wrong)
   ],

instead of

   "entities": [
      "dist/db/entity/**/*.js", // Pay attention to "dist" and "js" (this is the correct way)
   ],

Change Oracle port from port 8080

Execute Exec DBMS_XDB.SETHTTPPORT(8181); as SYS/SYSTEM. Replace 8181 with the port you'd like changing to. Tested this with Oracle 10g.

Source : http://hodentekhelp.blogspot.com/2008/08/my-oracle-10g-xe-is-on-port-8080-can-i.html

MVC If statement in View

Every time you use html syntax you have to start the next razor statement with a @. So it should be @if ....

post checkbox value

You should use

<input type="submit" value="submit" />

inside your form.

and add action into your form tag for example:

<form action="booking.php" method="post">

It's post your form into action which you choose.

From php you can get this value by

$_POST['booking-check'];

Split string with multiple delimiters in Python

In response to Jonathan's answer above, this only seems to work for certain delimiters. For example:

>>> a='Beautiful, is; better*than\nugly'
>>> import re
>>> re.split('; |, |\*|\n',a)
['Beautiful', 'is', 'better', 'than', 'ugly']

>>> b='1999-05-03 10:37:00'
>>> re.split('- :', b)
['1999-05-03 10:37:00']

By putting the delimiters in square brackets it seems to work more effectively.

>>> re.split('[- :]', b)
['1999', '05', '03', '10', '37', '00']

How do you replace double quotes with a blank space in Java?

Use String#replace().

To replace them with spaces (as per your question title):

System.out.println("I don't like these \"double\" quotes".replace("\"", " "));

The above can also be done with characters:

System.out.println("I don't like these \"double\" quotes".replace('"', ' '));

To remove them (as per your example):

System.out.println("I don't like these \"double\" quotes".replace("\"", ""));

How do I count the number of rows and columns in a file using bash?

Simple row count is $(wc -l "$file"). Use $(wc -lL "$file") to show both the number of lines and the number of characters in the longest line.

Accessing the last entry in a Map

When using numbers as the key, I suppose you could also try this:

        Map<Long, String> map = new HashMap<>();
        map.put(4L, "The First");
        map.put(6L, "The Second");
        map.put(11L, "The Last");

        long lastKey = 0;
        //you entered Map<Long, String> entry
        for (Map.Entry<Long, String> entry : map.entrySet()) {
            lastKey = entry.getKey();
        }
        System.out.println(lastKey); // 11

How to know the version of pip itself

Just for completeness:

pip -V

pip --version

pip list and inside the list you'll find also pip with its version.

What are the ways to make an html link open a folder

make sure your folder permissions are set so that a directory listing is allowed then just point your anchor to that folder using chmod 701 (that might be risky though) for example

<a href="./downloads/folder_i_want_to_display/" >Go to downloads page</a>

make sure that you have no index.html any index file on that directory

React native ERROR Packager can't listen on port 8081

On a mac, run the following command to find id of the process which is using port 8081
sudo lsof -i :8081
Then run the following to terminate process:
kill -9 23583

Here is how it will look like enter image description here

Can jQuery get all CSS styles associated with an element?

Two years late, but I have the solution you're looking for. Not intending to take credit form the original author, here's a plugin which I found works exceptionally well for what you need, but gets all possible styles in all browsers, even IE.

Warning: This code generates a lot of output, and should be used sparingly. It not only copies all standard CSS properties, but also all vendor CSS properties for that browser.

jquery.getStyleObject.js:

/*
 * getStyleObject Plugin for jQuery JavaScript Library
 * From: http://upshots.org/?p=112
 */

(function($){
    $.fn.getStyleObject = function(){
        var dom = this.get(0);
        var style;
        var returns = {};
        if(window.getComputedStyle){
            var camelize = function(a,b){
                return b.toUpperCase();
            };
            style = window.getComputedStyle(dom, null);
            for(var i = 0, l = style.length; i < l; i++){
                var prop = style[i];
                var camel = prop.replace(/\-([a-z])/g, camelize);
                var val = style.getPropertyValue(prop);
                returns[camel] = val;
            };
            return returns;
        };
        if(style = dom.currentStyle){
            for(var prop in style){
                returns[prop] = style[prop];
            };
            return returns;
        };
        return this.css();
    }
})(jQuery);

Basic usage is pretty simple, but he's written a function for that as well:

$.fn.copyCSS = function(source){
  var styles = $(source).getStyleObject();
  this.css(styles);
}

Hope that helps.

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

Adapt-Strap. Here is the fiddle.

It is extremely lightweight and has dynamic row heights.

<ad-table-lite table-name="carsForSale"
               column-definition="carsTableColumnDefinition"
               local-data-source="models.carsForSale"
               page-sizes="[7, 20]">
</ad-table-lite>

Testing javascript with Mocha - how can I use console.log to debug a test?

I had an issue with node.exe programs like test output with mocha.

In my case, I solved it by removing some default "node.exe" alias.

I'm using Git Bash for Windows(2.29.2) and some default aliases are set from /etc/profile.d/aliases.sh,

  # show me alias related to 'node'
  $ alias|grep node
  alias node='winpty node.exe'`

To remove the alias, update aliases.sh or simply do

unalias node

I don't know why winpty has this side effect on console.info buffered output but with a direct node.exe use, I've no more stdout issue.

Django URLs TypeError: view must be a callable or a list/tuple in the case of include()

Your code is

urlpatterns = [
    url(r'^$', 'myapp.views.home'),
    url(r'^contact/$', 'myapp.views.contact'),
    url(r'^login/$', 'django.contrib.auth.views.login'),
]

change it to following as you're importing include() function :

urlpatterns = [
    url(r'^$', views.home),
    url(r'^contact/$', views.contact),
    url(r'^login/$', views.login),
]

Cannot run emulator in Android Studio

  1. Go to "Edit the System Environment variables".
  2. Click on New Button and enter "ANDROID_SDK_ROOT" in variable name and enter android sdk full path in variable value. Click on ok and close.
  3. Refresh AVD.
  4. This will resolve error.

Eclipse Java error: This selection cannot be launched and there are no recent launches

click on the project that you want to run on the left side in package explorer and then click the Run button.

Tried to Load Angular More Than Once

I had this same problem ("Tried to Load Angular More Than Once") because I had included twice angularJs file (without perceive) in my index.html.

<script src="angular.js">
<script src="angular.min.js">

How to declare Return Types for Functions in TypeScript

Return types using arrow notation is the same as previous answers:

const sum = (a: number, b: number) : number => a + b;

Convert YYYYMMDD to DATE

I was also facing the same issue where I was receiving the Transaction_Date as YYYYMMDD in bigint format. So I converted it into Datetime format using below query and saved it in new column with datetime format. I hope this will help you as well.

SELECT
convert( Datetime, STUFF(STUFF(Transaction_Date, 5, 0, '-'), 8, 0, '-'), 120) As [Transaction_Date_New]
FROM mydb

Sending emails in Node.js?

campaign is a comprehensive solution for sending emails in Node, and it comes with a very simple API.

You instance it like this.

var client = require('campaign')({
  from: '[email protected]'
});

To send emails, you can use Mandrill, which is free and awesome. Just set your API key, like this:

process.env.MANDRILL_APIKEY = '<your api key>';

(if you want to send emails using another provider, check the docs)

Then, when you want to send an email, you can do it like this:

client.sendString('<p>{{something}}</p>', {
  to: ['[email protected]', '[email protected]'],
  subject: 'Some Subject',
  preview': 'The first line',
  something: 'this is what replaces that thing in the template'
}, done);

The GitHub repo has pretty extensive documentation.

ERROR Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies

check below link in which you can download suitable AjaxControlToolkit which suits your .NET version.

http://ajaxcontroltoolkit.codeplex.com/releases/view/43475

AjaxControlToolkit.Binary.NET4.zip - used for .NET 4.0

AjaxControlToolkit.Binary.NET35.zip - used for .NET 3.5

How do I unbind "hover" in jQuery?

Unbind the mouseenter and mouseleave events individually or unbind all events on the element(s).

$(this).unbind('mouseenter').unbind('mouseleave');

or

$(this).unbind();  // assuming you have no other handlers you want to keep

Using filesystem in node.js with async / await

I have this little helping module that exports promisified versions of fs functions

const fs = require("fs");
const {promisify} = require("util")

module.exports = {
  readdir: promisify(fs.readdir),
  readFile: promisify(fs.readFile),
  writeFile: promisify(fs.writeFile)
  // etc...
};

Root user/sudo equivalent in Cygwin?

Can't fully test this myself, I don't have a suitable script to try it out on, and I'm no Linux expert, but you might be able to hack something close enough.

I've tried these steps out, and they 'seem' to work, but don't know if it will suffice for your needs.

To get round the lack of a 'root' user:

  • Create a user on the LOCAL windows machine called 'root', make it a member of the 'Administrators' group
  • Mark the bin/bash.exe as 'Run as administrator' for all users (obviously you will have to turn this on/off as and when you need it)
  • Hold down the left shift button in windows explorer while right clicking on the Cygwin.bat file
  • Select 'Run as a different user'
  • Enter .\root as the username and then your password.

This then runs you as a user called 'root' in cygwin, which coupled with the 'Run as administrator' on the bash.exe file might be enough.

However you still need a sudo.

I faked this (and someone else with more linux knowledge can probably fake it better) by creating a file called 'sudo' in /bin and using this command line to send the command to su instead:

su -c "$*"

The command line 'sudo vim' and others seem to work ok for me, so you might want to try it out.

Be interested to know if this works for your needs or not.

What is the MySQL VARCHAR max size?

As per the online docs, there is a 64K row limit and you can work out the row size by using:

row length = 1
             + (sum of column lengths)
             + (number of NULL columns + delete_flag + 7)/8
             + (number of variable-length columns)

You need to keep in mind that the column lengths aren't a one-to-one mapping of their size. For example, CHAR(10) CHARACTER SET utf8 requires three bytes for each of the ten characters since that particular encoding has to account for the three-bytes-per-character property of utf8 (that's MySQL's utf8 encoding rather than "real" UTF-8, which can have up to four bytes).

But, if your row size is approaching 64K, you may want to examine the schema of your database. It's a rare table that needs to be that wide in a properly set up (3NF) database - it's possible, just not very common.

If you want to use more than that, you can use the BLOB or TEXT types. These do not count against the 64K limit of the row (other than a small administrative footprint) but you need to be aware of other problems that come from their use, such as not being able to sort using the entire text block beyond a certain number of characters (though this can be configured upwards), forcing temporary tables to be on disk rather than in memory, or having to configure client and server comms buffers to handle the sizes efficiently.

The sizes allowed are:

TINYTEXT          255 (+1 byte  overhead)
TEXT          64K - 1 (+2 bytes overhead)
MEDIUMTEXT    16M - 1 (+3 bytes overhead)
LONGTEXT      4G  - 1 (+4 bytes overhead)

You still have the byte/character mismatch (so that a MEDIUMTEXT utf8 column can store "only" about half a million characters, (16M-1)/3 = 5,592,405) but it still greatly expands your range.

Docker: adding a file from a parent directory

The solution for those who use composer is to use a volume pointing to the parent folder:

#docker-composer.yml

foo:
  build: foo
  volumes:
    - ./:/src/:ro

But I'm pretty sure the can be done playing with volumes in Dockerfile.

Convert int to ASCII and back in Python

>>> ord("a")
97
>>> chr(97)
'a'

Postgres integer arrays as parameters?

Full Coding Structure

postgresql function

CREATE OR REPLACE FUNCTION admin.usp_itemdisplayid_byitemhead_select(
    item_head_list int[])
    RETURNS TABLE(item_display_id integer) 
    LANGUAGE 'sql'

    COST 100
    VOLATILE 
    ROWS 1000
    
AS $BODY$ 
        SELECT vii.item_display_id from admin.view_item_information as vii
where vii.item_head_id = ANY(item_head_list);
    $BODY$;

Model

public class CampaignCreator
    {
        public int item_display_id { get; set; }
        public List<int> pitem_head_id { get; set; }
    }

.NET CORE function

DynamicParameters _parameter = new DynamicParameters();
                _parameter.Add("@item_head_list",obj.pitem_head_id);
                
                string sql = "select * from admin.usp_itemdisplayid_byitemhead_select(@item_head_list)";
                response.data = await _connection.QueryAsync<CampaignCreator>(sql, _parameter);

How to stop "setInterval"

Store the return of setInterval in a variable, and use it later to clear the interval.

var timer = null;
$("textarea").blur(function(){
    timer = window.setInterval(function(){ ... whatever ... }, 2000);
}).focus(function(){
    if(timer){
       window.clearInterval(timer);
       timer = null
    }
});

How can I symlink a file in Linux?

ln -s target linkName

You can have a look at the man page here:

http://linux.die.net/man/1/ln

How to prevent a double-click using jQuery?

This is my first ever post & I'm very inexperienced so please go easy on me, but I feel I've got a valid contribution that may be helpful to someone...

Sometimes you need a very big time window between repeat clicks (eg a mailto link where it takes a couple of secs for the email app to open and you don't want it re-triggered), yet you don't want to slow the user down elsewhere. My solution is to use class names for the links depending on event type, while retaining double-click functionality elsewhere...

var controlspeed = 0;

$(document).on('click','a',function (event) {
    eventtype = this.className;
    controlspeed ++;
    if (eventtype == "eg-class01") {
        speedlimit = 3000;
    } else if (eventtype == "eg-class02") { 
        speedlimit = 500; 
    } else { 
        speedlimit = 0; 
    } 
    setTimeout(function() {
        controlspeed = 0;
    },speedlimit);
    if (controlspeed > 1) {
        event.preventDefault();
        return;
    } else {

        (usual onclick code goes here)

    }
});

How to write to a file without overwriting current contents?

Instead of "w" use "a" (append) mode with open function:

with open("games.txt", "a") as text_file:

How can I tell Moq to return a Task?

Similar Issue

I have an interface that looked roughly like:

Task DoSomething(int arg);

Symptoms

My unit test failed when my service under test awaited the call to DoSomething.

Fix

Unlike the accepted answer, you are unable to call .ReturnsAsync() on your Setup() of this method in this scenario, because the method returns the non-generic Task, rather than Task<T>.

However, you are still able to use .Returns(Task.FromResult(default(object))) on the setup, allowing the test to pass.

Div with horizontal scrolling only

The solution is fairly straight forward. To ensure that we don't impact the width of the cells in the table, we'll turn off white-space. To ensure we get a horizontal scroll bar, we'll turn on overflow-x. And that's pretty much it:

.container {
    width: 30em;
    overflow-x: auto;
    white-space: nowrap;
}

You can see the end-result here, or in the animation below. If the table determines the height of your container, you should not need to explicitly set overflow-y to hidden. But understand that is also an option.

enter image description here

Explain the concept of a stack frame in a nutshell

"A call stack is composed of stack frames..." — Wikipedia

A stack frame is a thing that you put on the stack. They are data structures that contain information about subroutines to call.

Limit file format when using <input type="file">?

There is the accept attribute for the input tag. However, it is not reliable in any way. Browsers most likely treat it as a "suggestion", meaning the user will, depending on the file manager as well, have a pre-selection that only displays the desired types. They can still choose "all files" and upload any file they want.

For example:

_x000D_
_x000D_
<form>_x000D_
    <input type="file" name="pic" id="pic" accept="image/gif, image/jpeg" />_x000D_
</form>
_x000D_
_x000D_
_x000D_

Read more in the HTML5 spec

Keep in mind that it is only to be used as a "help" for the user to find the right files. Every user can send any request he/she wants to your server. You always have to validated everything server-side.

So the answer is: no you cannot restrict, but you can set a pre-selection but you cannot rely on it.

Alternatively or additionally you can do something similar by checking the filename (value of the input field) with JavaScript, but this is nonsense because it provides no protection and also does not ease the selection for the user. It only potentially tricks a webmaster into thinking he/she is protected and opens a security hole. It can be a pain in the ass for users that have alternative file extensions (for example jpeg instead of jpg), uppercase, or no file extensions whatsoever (as is common on Linux systems).

Convert List into Comma-Separated String

you can also override ToString() if your list item have more than one string

public class ListItem
{

    public string string1 { get; set; }

    public string string2 { get; set; }

    public string string3 { get; set; }

    public override string ToString()
    {
        return string.Join(
        ","
        , string1 
        , string2 
        , string3);

    }

}

to get csv string:

ListItem item = new ListItem();
item.string1 = "string1";
item.string2 = "string2";
item.string3 = "string3";

List<ListItem> list = new List<ListItem>();
list.Add(item);

string strinCSV = (string.Join("\n", list.Select(x => x.ToString()).ToArray()));

How can I tell AngularJS to "refresh"

Why $apply should be called?

TL;DR: $apply should be called whenever you want to apply changes made outside of Angular world.


Just to update @Dustin's answer, here is an explanation of what $apply exactly does and why it works.

$apply() is used to execute an expression in AngularJS from outside of the AngularJS framework. (For example from browser DOM events, setTimeout, XHR or third party libraries). Because we are calling into the AngularJS framework we need to perform proper scope life cycle of exception handling, executing watches.

Angular allows any value to be used as a binding target. Then at the end of any JavaScript code turn, it checks to see if the value has changed. That step that checks to see if any binding values have changed actually has a method, $scope.$digest()1. We almost never call it directly, as we use $scope.$apply() instead (which will call $scope.$digest).

Angular only monitors variables used in expressions and anything inside of a $watch living inside the scope. So if you are changing the model outside of the Angular context, you will need to call $scope.$apply() for those changes to be propagated, otherwise Angular will not know that they have been changed thus the binding will not be updated2.

Can I run javascript before the whole page is loaded?

Not only can you, but you have to make a special effort not to if you don't want to. :-)

When the browser encounters a classic script tag when parsing the HTML, it stops parsing and hands over to the JavaScript interpreter, which runs the script. The parser doesn't continue until the script execution is complete (because the script might do document.write calls to output markup that the parser should handle).

That's the default behavior, but you have a few options for delaying script execution:

  1. Use JavaScript modules. A type="module" script is deferred until the HTML has been fully parsed and the initial DOM created. This isn't the primary reason to use modules, but it's one of the reasons:

    <script type="module" src="./my-code.js"></script>
    <!-- Or -->
    <script type="module">
    // Your code here
    </script>
    

    The code will be fetched (if it's separate) and parsed in parallel with the HTML parsing, but won't be run until the HTML parsing is done. (If your module code is inline rather than in its own file, it is also deferred until HTML parsing is complete.)

    This wasn't available when I first wrote this answer in 2010, but here in 2020, all major modern browsers support modules natively, and if you need to support older browsers, you can use bundlers like Webpack and Rollup.js.

  2. Use the defer attribute on a classic script tag:

    <script defer src="./my-code.js"></script>
    

    As with the module, the code in my-code.js will be fetched and parsed in parallel with the HTML parsing, but won't be run until the HTML parsing is done. But, defer doesn't work with inline script content, only with external files referenced via src.

  3. I don't think it's what you want, but you can use the async attribute to tell the browser to fetch the JavaScript code in parallel with the HTML parsing, but then run it as soon as possible, even if the HTML parsing isn't complete. You can put it on a type="module" tag, or use it instead of defer on a classic script tag.

  4. Put the script tag at the end of the document, just prior to the closing </body> tag:

    <!doctype html>
    <html>
    <!-- ... -->
    <body>
    <!-- The document's HTML goes here -->
    <script type="module" src="./my-code.js"></script><!-- Or inline script -->
    </body>
    </html>
    

    That way, even though the code is run as soon as its encountered, all of the elements defined by the HTML above it exist and are ready to be used.

    It used to be that this caused an additional delay on some browsers because they wouldn't start fetching the code until the script tag was encountered, but modern browsers scan ahead and start prefetching. Still, this is very much the third choice at this point, both modules and defer are better options.

The spec has a useful diagram showing a raw script tag, defer, async, type="module", and type="module" async and the timing of when the JavaScript code is fetched and run:

enter image description here

Here's an example of the default behavior, a raw script tag:

_x000D_
_x000D_
.found {_x000D_
    color: green;_x000D_
}
_x000D_
<p>Paragraph 1</p>_x000D_
<script>_x000D_
    if (typeof NodeList !== "undefined" && !NodeList.prototype.forEach) {_x000D_
        NodeList.prototype.forEach = Array.prototype.forEach;_x000D_
    }_x000D_
    document.querySelectorAll("p").forEach(p => {_x000D_
        p.classList.add("found");_x000D_
    });_x000D_
</script>_x000D_
<p>Paragraph 2</p>
_x000D_
_x000D_
_x000D_

(See my answer here for details around that NodeList code.)

When you run that, you see "Paragraph 1" in green but "Paragraph 2" is black, because the script ran synchronously with the HTML parsing, and so it only found the first paragraph, not the second.

In contrast, here's a type="module" script:

_x000D_
_x000D_
.found {_x000D_
    color: green;_x000D_
}
_x000D_
<p>Paragraph 1</p>_x000D_
<script type="module">_x000D_
    document.querySelectorAll("p").forEach(p => {_x000D_
        p.classList.add("found");_x000D_
    });_x000D_
</script>_x000D_
<p>Paragraph 2</p>
_x000D_
_x000D_
_x000D_

Notice how they're both green now; the code didn't run until HTML parsing was complete. That would also be true with a defer script with external content (but not inline content).

(There was no need for the NodeList check there because any modern browser supporting modules already has forEach on NodeList.)

In this modern world, there's no real value to the DOMContentLoaded event of the "ready" feature that PrototypeJS, jQuery, ExtJS, Dojo, and most others provided back in the day (and still provide); just use modules or defer. Even back in the day, there wasn't much reason for using them (and they were often used incorrectly, holding up page presentation while the entire jQuery library was loaded because the script was in the head instead of after the document), something some developers at Google flagged up early on. This was also part of the reason for the YUI recommendation to put scripts at the end of the body, again back in the day.

How to call a javaScript Function in jsp on page load without using <body onload="disableView()">

Either use window.onload this way

<script>
    window.onload = function() {
        // ...
    }
</script>

or alternatively

<script>
    window.onload = functionName;
</script>

(yes, without the parentheses)


Or just put the script at the very bottom of page, right before </body>. At that point, all HTML DOM elements are ready to be accessed by document functions.

<body>
    ...

    <script>
        functionName();
    </script>
</body>

Using Notepad++ to validate XML against an XSD

  1. In Notepad++ go to Plugins > Plugin manager > Show Plugin Manager then find Xml Tools plugin. Tick the box and click Install

    enter image description here

  2. Open XML document you want to validate and click Ctrl+Shift+Alt+M (Or use Menu if this is your preference Plugins > XML Tools > Validate Now).
    Following dialog will open: enter image description here

  3. Click on .... Point to XSD file and I am pretty sure you'll be able to handle things from here.

Hope this saves you some time.

EDIT: Plugin manager was not included in some versions of Notepad++ because many users didn't like commercials that it used to show. If you want to keep an older version, however still want plugin manager, you can get it on github, and install it by extracting the archive and copying contents to plugins and updates folder.
In version 7.7.1 plugin manager is back under a different guise... Plugin Admin so now you can simply update notepad++ and have it back.

enter image description here

How do I revert an SVN commit?

Both examples must work, but

svn merge -r UPREV:LOWREV . undo range

svn merge -c -REV . undo single revision

in this syntax - if current dir is WC and (as in must done after every merge) you'll commit results

Do you want to see logs?

How to count rows with SELECT COUNT(*) with SQLAlchemy?

Query for just a single known column:

session.query(MyTable.col1).count()

Trim to remove white space

jQuery.trim() capital Q?

or $.trim()

setHintTextColor() in EditText

Default Colors:

android:textColorHint="@android:color/holo_blue_dark"

For Color code:

android:textColorHint="#33b5e5"

Different ways of adding to Dictionary

The first version will add a new KeyValuePair to the dictionary, throwing if key is already in the dictionary. The second, using the indexer, will add a new pair if the key doesn't exist, but overwrite the value of the key if it already exists in the dictionary.

IDictionary<string, string> strings = new Dictionary<string, string>();

strings["foo"] = "bar";          //strings["foo"] == "bar"
strings["foo"] = string.Empty;   //strings["foo"] == string.empty
strings.Add("foo", "bar");       //throws     

How to fetch FetchType.LAZY associations with JPA and Hibernate in a Spring Controller

Spring Data JpaRepository

The Spring Data JpaRepository defines the following two methods:

  • getOne, which returns an entity proxy that is suitable for setting a @ManyToOne or @OneToOne parent association when persisting a child entity.
  • findById, which returns the entity POJO after running the SELECT statement that loads the entity from the associated table

However, in your case, you didn't call either getOne or findById:

Person person = personRepository.findOne(1L);

So, I assume the findOne method is a method you defined in the PersonRepository. However, the findOne method is not very useful in your case. Since you need to fetch the Person along with is roles collection, it's better to use a findOneWithRoles method instead.

Custom Spring Data methods

You can define a PersonRepositoryCustom interface, as follows:

public interface PersonRepository
    extends JpaRepository<Person, Long>, PersonRepositoryCustom { 

}

public interface PersonRepositoryCustom {
    Person findOneWithRoles(Long id);
}

And define its implementation like this:

public class PersonRepositoryImpl implements PersonRepositoryCustom {

    @PersistenceContext
    private EntityManager entityManager;

    @Override
    public Person findOneWithRoles(Long id)() {
        return entityManager.createQuery("""
            select p 
            from Person p
            left join fetch p.roles
            where p.id = :id 
            """, Person.class)
        .setParameter("id", id)
        .getSingleResult();
    }
}

That's it!

Terminating a script in PowerShell

Exit will exit PowerShell too. If you wish to "break" out of just the current function or script - use Break :)

If ($Breakout -eq $true)
{
     Write-Host "Break Out!"
     Break
}
ElseIf ($Breakout -eq $false)
{
     Write-Host "No Breakout for you!"
}
Else
{
    Write-Host "Breakout wasn't defined..."
}

Inline IF Statement in C#

You may define your enum like so and use cast where needed

public enum MyEnum
{
    VariablePeriods = 1,
    FixedPeriods = 2
}

Usage

public class Entity
{
    public MyEnum Property { get; set; }
}

var returnedFromDB = 1;
var entity = new Entity();
entity.Property = (MyEnum)returnedFromDB;

Javascript to convert UTC to local time

This works for both Chrome and Firefox.
Not tested on other browsers.

_x000D_
_x000D_
const convertToLocalTime = (dateTime, notStanderdFormat = true) => {
  if (dateTime !== null && dateTime !== undefined) {
    if (notStanderdFormat) {
      // works for 2021-02-21 04:01:19
      // convert to 2021-02-21T04:01:19.000000Z format before convert to local time
      const splited = dateTime.split(" ");
      let convertedDateTime = `${splited[0]}T${splited[1]}.000000Z`;
      const date = new Date(convertedDateTime);
      return date.toString();
    } else {
      // works for 2021-02-20T17:52:45.000000Z or  1613639329186
      const date = new Date(dateTime);
      return date.toString();
    }
  } else {
    return "Unknown";
  }
};

// TEST

console.log(convertToLocalTime('2012-11-29 17:00:34 UTC'));
_x000D_
_x000D_
_x000D_

How to connect Android app to MySQL database?

Use android vollley, it is very fast and you can betterm manipulate requests. Send post request using Volley and receive in PHP

Basically, you will create a map with key-value params for the php request(POST/GET), the php will do the desired processing and you will return the data as JSON(json_encode()). Then you can either parse the JSON as needed or use GSON from Google to let it do the parsing.

PHP convert XML to JSON

All solutions here have problems!

... When the representation need perfect XML interpretation (without problems with attributes) and to reproduce all text-tag-text-tag-text-... and order of tags. Also good remember here that JSON object "is an unordered set" (not repeat keys and the keys can't have predefined order)... Even ZF's xml2json is wrong (!) because not preserve exactly the XML structure.

All solutions here have problems with this simple XML,

    <states x-x='1'>
        <state y="123">Alabama</state>
        My name is <b>John</b> Doe
        <state>Alaska</state>
    </states>

... @FTav solution seems better than 3-line solution, but also have little bug when tested with this XML.

Old solution is the best (for loss-less representation)

The solution, today well-known as jsonML, is used by Zorba project and others, and was first presented in ~2006 or ~2007, by (separately) Stephen McKamey and John Snelson.

// the core algorithm is the XSLT of the "jsonML conventions"
// see  https://github.com/mckamey/jsonml
$xslt = 'https://raw.githubusercontent.com/mckamey/jsonml/master/jsonml.xslt';
$dom = new DOMDocument;
$dom->loadXML('
    <states x-x=\'1\'>
        <state y="123">Alabama</state>
        My name is <b>John</b> Doe
        <state>Alaska</state>
    </states>
');
if (!$dom) die("\nERROR!");
$xslDoc = new DOMDocument();
$xslDoc->load($xslt);
$proc = new XSLTProcessor();
$proc->importStylesheet($xslDoc);
echo $proc->transformToXML($dom);

Produce

["states",{"x-x":"1"},
    "\n\t    ",
    ["state",{"y":"123"},"Alabama"],
    "\n\t\tMy name is ",
    ["b","John"],
    " Doe\n\t    ",
    ["state","Alaska"],
    "\n\t"
]

See http://jsonML.org or github.com/mckamey/jsonml. The production rules of this JSON are based on the element JSON-analog,

enter image description here

This syntax is a element definition and recurrence, with
element-list ::= element ',' element-list | element.

Finding duplicate values in a SQL table

try this:

declare @YourTable table (id int, name varchar(10), email varchar(50))

INSERT @YourTable VALUES (1,'John','John-email')
INSERT @YourTable VALUES (2,'John','John-email')
INSERT @YourTable VALUES (3,'fred','John-email')
INSERT @YourTable VALUES (4,'fred','fred-email')
INSERT @YourTable VALUES (5,'sam','sam-email')
INSERT @YourTable VALUES (6,'sam','sam-email')

SELECT
    name,email, COUNT(*) AS CountOf
    FROM @YourTable
    GROUP BY name,email
    HAVING COUNT(*)>1

OUTPUT:

name       email       CountOf
---------- ----------- -----------
John       John-email  2
sam        sam-email   2

(2 row(s) affected)

if you want the IDs of the dups use this:

SELECT
    y.id,y.name,y.email
    FROM @YourTable y
        INNER JOIN (SELECT
                        name,email, COUNT(*) AS CountOf
                        FROM @YourTable
                        GROUP BY name,email
                        HAVING COUNT(*)>1
                    ) dt ON y.name=dt.name AND y.email=dt.email

OUTPUT:

id          name       email
----------- ---------- ------------
1           John       John-email
2           John       John-email
5           sam        sam-email
6           sam        sam-email

(4 row(s) affected)

to delete the duplicates try:

DELETE d
    FROM @YourTable d
        INNER JOIN (SELECT
                        y.id,y.name,y.email,ROW_NUMBER() OVER(PARTITION BY y.name,y.email ORDER BY y.name,y.email,y.id) AS RowRank
                        FROM @YourTable y
                            INNER JOIN (SELECT
                                            name,email, COUNT(*) AS CountOf
                                            FROM @YourTable
                                            GROUP BY name,email
                                            HAVING COUNT(*)>1
                                        ) dt ON y.name=dt.name AND y.email=dt.email
                   ) dt2 ON d.id=dt2.id
        WHERE dt2.RowRank!=1
SELECT * FROM @YourTable

OUTPUT:

id          name       email
----------- ---------- --------------
1           John       John-email
3           fred       John-email
4           fred       fred-email
5           sam        sam-email

(4 row(s) affected)

Php header location redirect not working

Make Sure that you don't leave a space before <?php when you start <?php tag at the top of the page.

"No cached version... available for offline mode."

Please follow below steps :

1.Open Your project.

2.Go to the Left side of the Gradle button.

3.Look at below image.

enter image description here

4.Click button above image show.

5.if this type of view you are not in offline mode.

6.Go to Build and rebuild the project.

All above point is work for me.

Calculate date/time difference in java

// d1, d2 are dates
long diff = d2.getTime() - d1.getTime();

long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);

System.out.print(diffDays + " days, ");
System.out.print(diffHours + " hours, ");
System.out.print(diffMinutes + " minutes, ");
System.out.print(diffSeconds + " seconds.");

Regular Expression For Duplicate Words

The widely-used PCRE library can handle such situations (you won't achieve the the same with POSIX-compliant regex engines, though):

(\b\w+\b)\W+\1

What is the "assert" function?

Stuff like 'raises exception' and 'halts execution' might be true for most compilers, but not for all. (BTW, are there assert statements that really throw exceptions?)

Here's an interesting, slightly different meaning of assert used by c6x and other TI compilers: upon seeing certain assert statements, these compilers use the information in that statement to perform certain optimizations. Wicked.

Example in C:

int dot_product(short *x, short *y, short z)
{
  int sum = 0
  int i;

  assert( ( (int)(x) & 0x3 ) == 0 );
  assert( ( (int)(y) & 0x3 ) == 0 );

  for( i = 0 ; i < z ; ++i )
    sum += x[ i ] * y[ i ];
  return sum;
}

This tells de compiler the arrays are aligned on 32-bits boundaries, so the compiler can generate specific instructions made for that kind of alignment.

Disable Buttons in jQuery Mobile

You are getting that error probably because the element is not within the DOM yet. $(document).ready(); will not work. Try adding your code to a pageinit event handler.

Here is a working example:

<!DOCTYPE html> 
<html> 
<head>
    <title>Button Disable</title> 
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link rel="stylesheet" href="http://code.jquery.com/mobile/1.0/jquery.mobile-1.0.min.css" />
    <script type="text/javascript" src="http://code.jquery.com/jquery-1.6.4.min.js"></script>
    <script type="text/javascript" src="http://code.jquery.com/mobile/1.0/jquery.mobile-1.0.min.js"></script>
</head> 
<body>
    <div id="MyPageId" data-role="page">
        <div data-role="header">
            <h1>Button Disable</h1>
        </div>
        <div data-role="content">
            <button id="button1" type="button" onclick="javascript:alert('#button1 clicked');">Button 1</button>
            <button id="button2" type="button" onclick="javascript:alert('#button2 clicked');">Button 2</button>
        </div>
        <div data-role="footer">
            <p>footer</p>
        </div>
    </div>
    <script type="text/javascript">//<![CDATA[
        $('#MyPageId').bind("pageinit", function (event, data) {
            $("#button1").button("disable");
        });
    //]]></script>
</body>
</html>

Hope that helps someone

How to check for valid email address?

I found an excellent (and tested) way to check for valid email address. I paste my code here:

# here i import the module that implements regular expressions
import re
# here is my function to check for valid email address
def test_email(your_pattern):
pattern = re.compile(your_pattern)
# here is an example list of email to check it at the end
emails = ["[email protected]", "[email protected]", "wha.t.`1an?ug{}[email protected]"]
for email in emails:
    if not re.match(pattern, email):
        print "You failed to match %s" % (email)
    elif not your_pattern:
        print "Forgot to enter a pattern!"
    else:
        print "Pass"
# my pattern that is passed as argument in my function is here!
pattern = r"\"?([-a-zA-Z0-9.`?{}]+@\w+\.\w+)\"?"   
# here i test my function passing my pattern
test_email(pattern)

How to vertically align a html radio button to it's label?

label, input {
    vertical-align: middle;
}

I'm just align the vertical midpoint of the boxes with the baseline of the parent box plus half the x-height (en.wikipedia.org/wiki/X-height) of the parent.

What is the purpose for using OPTION(MAXDOP 1) in SQL Server?

Adding my two cents, based on a performance issue I observed.

If simple queries are getting parellelized unnecessarily, it can bring more problems than solving one. However, before adding MAXDOP into the query as "knee-jerk" fix, there are some server settings to check.

In Jeremiah Peschka - Five SQL Server Settings to Change, MAXDOP and "COST THRESHOLD FOR PARALLELISM" (CTFP) are mentioned as important settings to check.

Note: Paul White mentioned max server memory aslo as a setting to check, in a response to Performance problem after migration from SQL Server 2005 to 2012. A good kb article to read is Using large amounts of memory can result in an inefficient plan in SQL Server

Jonathan Kehayias - Tuning ‘cost threshold for parallelism’ from the Plan Cache helps to find out good value for CTFP.

Why is cost threshold for parallelism ignored?

Aaron Bertrand - Six reasons you should be nervous about parallelism has a discussion about some scenario where MAXDOP is the solution.

Parallelism-Inhibiting Components are mentioned in Paul White - Forcing a Parallel Query Execution Plan

Skip a submodule during a Maven build

Sure, this can be done using profiles. You can do something like the following in your parent pom.xml.

  ...
   <modules>
      <module>module1</module>
      <module>module2</module>  
      ...
  </modules>
  ...
  <profiles>
     <profile>
       <id>ci</id>
          <modules>
            <module>module1</module>
            <module>module2</module>
            ...
            <module>module-integration-test</module>
          </modules> 
      </profile>
  </profiles>
 ...

In your CI, you would run maven with the ci profile, i.e. mvn -P ci clean install

How to print binary tree diagram?

  1. You will need to level order traverse your tree.
  2. Choose node length and space length.
  3. Get the tree's base width relative to each level which is node_length * nodes_count + space_length * spaces_count*.
  4. Find a relation between branching, spacing, indentation and the calculated base width.

Code on GitHub: YoussefRaafatNasry/bst-ascii-visualization

                                             07                     
                                             /\                     
                                            /  \                    
                                           /    \                   
                                          /      \                  
                                         /        \                 
                                        /          \                
                                       /            \               
                                      /              \              
                                     /                \             
                                    /                  \            
                                   /                    \           
                                 03                      11         
                                 /\                      /\         
                                /  \                    /  \        
                               /    \                  /    \       
                              /      \                /      \      
                             /        \              /        \     
                           01          05          09          13   
                           /\          /\          /\          /\   
                          /  \        /  \        /  \        /  \  
                        00    02    04    06    08    10    12    14

npm WARN enoent ENOENT: no such file or directory, open 'C:\Users\Nuwanst\package.json'

Have you created a package.json file? Maybe run this command first again.

C:\Users\Nuwanst\Documents\NodeJS\3.chat>npm init

It creates a package.json file in your folder.

Then run,

C:\Users\Nuwanst\Documents\NodeJS\3.chat>npm install socket.io --save

The --save ensures your module is saved as a dependency in your package.json file.

Let me know if this works.

View stored procedure/function definition in MySQL

You can use this:

SELECT ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES
WHERE ROUTINE_SCHEMA = 'yourdb' AND ROUTINE_TYPE = 'PROCEDURE' AND ROUTINE_NAME = "procedurename";

Error: Can't set headers after they are sent to the client

I got a similar error when I tried to send response within a loop function. The simple solution was to move the

res.send('send response');

out of the loop since you can only send response header once.

https://www.tutorialspoint.com/nodejs/nodejs_response_object.htm

The point of test %eax %eax

You are right, that test "and"s the two operands. But the result is discarded, the only thing that stays, and thats the important part, are the flags. They are set and thats the reason why the test instruction is used (and exist).

JE jumps not when equal (it has the meaning when the instruction before was a comparison), what it really does, it jumps when the ZF flag is set. And as it is one of the flags that is set by test, this instruction sequence (test x,x; je...) has the meaning that it is jumped when x is 0.

For questions like this (and for more details) I can just recommend a book about x86 instruction, e.g. even when it is really big, the Intel documentation is very good and precise.

OR condition in Regex

I think what you need might be simply:

\d( \w)?

Note that your regex would have worked too if it was written as \d \w|\d instead of \d|\d \w.

This is because in your case, once the regex matches the first option, \d, it ceases to search for a new match, so to speak.

How to change the style of a DatePicker in android?

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

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

Why can't I check if a 'DateTime' is 'Nothing'?

Some examples on working with nullable DateTime values.

(See Nullable Value Types (Visual Basic) for more.)

'
' An ordinary DateTime declaration. It is *not* nullable. Setting it to
' 'Nothing' actually results in a non-null value.
'
Dim d1 As DateTime = Nothing
Console.WriteLine(String.Format("d1 = [{0}]\n", d1))
' Output:  d1 = [1/1/0001 12:00:00 AM]

' Console.WriteLine(String.Format("d1 is Nothing? [{0}]\n", (d1 Is Nothing)))
'
'   Compilation error on above expression '(d1 Is Nothing)':
'
'      'Is' operator does not accept operands of type 'Date'.
'       Operands must be reference or nullable types.

'
' Three different but equivalent ways to declare a DateTime
' nullable:
'
Dim d2? As DateTime = Nothing
Console.WriteLine(String.Format("d2 = [{0}][{1}]\n", d2, (d2 Is Nothing)))
' Output:  d2 = [][True]

Dim d3 As DateTime? = Nothing
Console.WriteLine(String.Format("d3 = [{0}][{1}]\n", d3, (d3 Is Nothing)))
' Output:  d3 = [][True]

Dim d4 As Nullable(Of DateTime) = Nothing
Console.WriteLine(String.Format("d4 = [{0}][{1}]\n", d4, (d4 Is Nothing)))
' Output:  d4 = [][True]

Also, on how to check whether a variable is null (from Nothing (Visual Basic)):

When checking whether a reference (or nullable value type) variable is null, do not use = Nothing or <> Nothing. Always use Is Nothing or IsNot Nothing.

If Else If In a Sql Server Function

No one seems to have picked that if (yes=no)>na or (no=na)>yes or (na=yes)>no, you get NULL as the result. Don't believe this is what you are after.

Here's also a more condensed form of the function, which works even if any of yes, no or na_ans is NULL.

USE [***]
GO
/****** Object:  UserDefinedFunction [dbo].[fnActionSq]    Script Date: 02/17/2011 10:21:47 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION [dbo].[fnTally] (@SchoolId nvarchar(50))
RETURNS nvarchar(3)
AS 
BEGIN
return (select (
       select top 1 Result from
       (select 'Yes' Result, yes_ans union all
        select 'No', no_ans union all
        select 'N/A', na_ans) [ ]
        order by yes_ans desc, Result desc)
       from dbo.qrc_maintally
       where school_id = @SchoolId)
End

Conversion from List<T> to array T[]

Try using

MyClass[] myArray = list.ToArray();

Disable JavaScript error in WebBrowser control

This disables the script errors and also disables other windows.. such as the NTLM login window or the client certificate accept window. The below will suppress only javascript errors.

// Hides script errors without hiding other dialog boxes.
private void SuppressScriptErrorsOnly(WebBrowser browser)
{
    // Ensure that ScriptErrorsSuppressed is set to false.
    browser.ScriptErrorsSuppressed = false;

    // Handle DocumentCompleted to gain access to the Document object.
    browser.DocumentCompleted +=
        new WebBrowserDocumentCompletedEventHandler(
            browser_DocumentCompleted);
}

private void browser_DocumentCompleted(object sender, 
    WebBrowserDocumentCompletedEventArgs e)
{
    ((WebBrowser)sender).Document.Window.Error += 
        new HtmlElementErrorEventHandler(Window_Error);
}

private void Window_Error(object sender, 
    HtmlElementErrorEventArgs e)
{
    // Ignore the error and suppress the error dialog box. 
    e.Handled = true;
}

Polynomial time and exponential time

Check this out.

Exponential is worse than polynomial.

O(n^2) falls into the quadratic category, which is a type of polynomial (the special case of the exponent being equal to 2) and better than exponential.

Exponential is much worse than polynomial. Look at how the functions grow

n    = 10    |     100   |      1000

n^2  = 100   |   10000   |   1000000 

k^n  = k^10  |   k^100   |    k^1000

k^1000 is exceptionally huge unless k is smaller than something like 1.1. Like, something like every particle in the universe would have to do 100 billion billion billion operations per second for trillions of billions of billions of years to get that done.

I didn't calculate it out, but ITS THAT BIG.

How to work on UAC when installing XAMPP

You can press ok and it will continue the insallation.

Otherwise, see Trying to reinstall XAMPP on windows 7, getting error messag...

How do I convert from BLOB to TEXT in MySQL?

SELECCT TO_BASE64(blobfield)  
FROM the Table

worked for me.

The CAST(blobfield AS CHAR(10000) CHARACTER SET utf8) and CAST(blobfield AS CHAR(10000) CHARACTER SET utf16) did not show me the text value I wanted to get.

How to Set focus to first text input in a bootstrap modal after shown

if you're looking for a snippet that would work for all your modals, and search automatically for the 1st input text in the opened one, you should use this:

$('.modal').on('shown.bs.modal', function () {
    $(this).find( 'input:visible:first').focus();
});

If your modal is loaded using ajax, use this instead:

$(document).on('shown.bs.modal', '.modal', function() {
    $(this).find('input:visible:first').focus();
});

Android ACTION_IMAGE_CAPTURE Intent

The file needs be writable by the camera, as Praveen pointed out.

In my usage I wanted to store the file in internal storage. I did this with:

Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (i.resolveActivity(getPackageManager()!=null)){
    try{
        cacheFile = createTempFile("img",".jpg",getCacheDir());
        cacheFile.setWritavle(true,false);
    }catch(IOException e){}
    if(cacheFile != null){
        i.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(cacheFile));
        startActivityForResult(i,REQUEST_IMAGE_CAPTURE);
    }
}

Here cacheFile is a global file used to refer to the file which is written. Then in the result method the returned intent is null. Then the method for processing the intent looks like:

protected void onActivityResult(int requestCode,int resultCode,Intent data){
    if(requestCode != RESULT_OK){
        return;
    }
    if(requestCode == REQUEST_IMAGE_CAPTURE){
        try{
            File output = getImageFile();
            if(output != null && cacheFile != null){
                copyFile(cacheFile,output);

                //Process image file stored at output

                cacheFile.delete();
                cacheFile=null;
            }
        }catch(IOException e){}
    }
}

Here getImageFile() is a utility method to name and create the file in which the image should be stored, and copyFile() is a method to copy a file.

What is the purpose of flush() in Java streams?

For performance issue, first data is to be written into Buffer. When buffer get full then data is written to output (File,console etc.). When buffer is partially filled and you want to send it to output(file,console) then you need to call flush() method manually in order to write partially filled buffer to output(file,console).

SSRS Query execution failed for dataset

I just dealt with this same issue. Make sure your query lists the full source name, using no shortcuts. Visual Studio can recognize the shortcuts, but your reporting services application may not be able to recognize which tables your data should be coming from. Hope that helps.

curl : (1) Protocol https not supported or disabled in libcurl

This is specifically mentioned in the libcurl FAQ entry "Protocol xxx not supported or disabled in libcurl".

For your pleasure I'm embedding the explanation here too:

When passing on a URL to curl to use, it may respond that the particular protocol is not supported or disabled. The particular way this error message is phrased is because curl doesn't make a distinction internally of whether a particular protocol is not supported (ie never got any code added that knows how to speak that protocol) or if it was explicitly disabled. curl can be built to only support a given set of protocols, and the rest would then be disabled or not supported.

Note that this error will also occur if you pass a wrongly spelled protocol part as in "htpt://example.com" or as in the less evident case if you prefix the protocol part with a space as in " http://example.com/".

Getting the last revision number in SVN?

Someone else beat me to posting the answer about svnversion, which is definitely the best solution if you have a working copy (IIRC, it doesn't work with URLs). I'll add this: if you're on the server hosting SVN, the best way is to use the svnlook command. This is the command you use when writing a hook script to inspect the repository (and even the current transaction, in the case of pre-commit hooks). You can type svnlook help for details. You probably want to use the svnlook youngest command. Note that it requires direct access to the repo directory, so it must be used on the server.

Select the first 10 rows - Laravel Eloquent

The simplest way in laravel 5 is:

$listings=Listing::take(10)->get();

return view('view.name',compact('listings'));

How to pass extra variables in URL with WordPress

to add parameter to post urls (to perma-links), i use this:

add_filter( 'post_type_link', 'append_query_string', 10, 2 );
function append_query_string( $url, $post ) 
{
    return add_query_arg('my_pid',$post->ID, $url);
}

output:

http://yoursite.com/pagename?my_pid=12345678

how to fetch data from database in Hibernate

I know that it is very late to answer the question, but it may help someone like me who spent lots off time to fetch data using hql

So the thing is you just have to write a query

Query query = session.createQuery("from Employee");

it will give you all the data list but to fetch data from this you have to write this line.

List<Employee> fetchedData = query.list();

As simple as it looks.

Replacing all non-alphanumeric characters with empty strings

Simple method:

public boolean isBlank(String value) {
    return (value == null || value.equals("") || value.equals("null") || value.trim().equals(""));
}

public String normalizeOnlyLettersNumbers(String str) {
    if (!isBlank(str)) {
        return str.replaceAll("[^\\p{L}\\p{Nd}]+", "");
    } else {
        return "";
    }
}

How to verify an XPath expression in Chrome Developers tool or Firefox's Firebug?

By using Chrome or Opera

without any plugins, without writing any single XPath syntax character

  1. right click the required element, then "inspect"
  2. right click on highlighted element tag, choose Copy ? Copy XPath.

;)

Enter image description here

jQuery select2 get value of select tag?

To get Select element you can use $('#first').val();

To get the text of selected value - $('#first :selected').text();

Can you please post your select2() function code

How to pass a value from Vue data to href?

If you want to display links coming from your state or store in Vue 2.0, you can do like this:

<a v-bind:href="''"> {{ url_link }} </a>

Getting first and last day of the current month

var myDate = DateTime.Now;
var startOfMonth = new DateTime(myDate.Year, myDate.Month, 1);
var endOfMonth = startOfMonth.AddMonths(1).AddDays(-1);

That should give you what you need.

Set height of chart in Chart.js

He's right. If you want to stay with jQuery you could do this

var ctx = $('#myChart')[0];
ctx.height = 500;

or

var ctx = $('#myChart');
ctx.attr('height',500);

How to open mail app from Swift

Here how it looks for Swift 4:

import MessageUI

if MFMailComposeViewController.canSendMail() {
    let mail = MFMailComposeViewController()
    mail.mailComposeDelegate = self
    mail.setToRecipients(["[email protected]"])
    mail.setSubject("Bla")
    mail.setMessageBody("<b>Blabla</b>", isHTML: true)
    present(mail, animated: true, completion: nil)
} else {
    print("Cannot send mail")
    // give feedback to the user
}

func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
        switch result.rawValue {
        case MFMailComposeResult.cancelled.rawValue:
            print("Cancelled")
        case MFMailComposeResult.saved.rawValue:
            print("Saved")
        case MFMailComposeResult.sent.rawValue:
            print("Sent")
        case MFMailComposeResult.failed.rawValue:
            print("Error: \(String(describing: error?.localizedDescription))")
        default:
            break
        }
        controller.dismiss(animated: true, completion: nil)
    }

Function Pointers in Java

Relative to most people here I am new to java but since I haven't seen a similar suggestion I have another alternative to suggest. Im not sure if its a good practice or not, or even suggested before and I just didn't get it. I just like it since I think its self descriptive.

 /*Just to merge functions in a common name*/
 public class CustomFunction{ 
 public CustomFunction(){}
 }

 /*Actual functions*/
 public class Function1 extends CustomFunction{
 public Function1(){}
 public void execute(){...something here...}
 }

 public class Function2 extends CustomFunction{
 public Function2(){}
 public void execute(){...something here...}
 }

 .....
 /*in Main class*/
 CustomFunction functionpointer = null;

then depending on the application, assign

 functionpointer = new Function1();
 functionpointer = new Function2();

etc.

and call by

 functionpointer.execute();

Is it possible to run selenium (Firefox) web driver without a GUI?

Yes. You can use HTMLUnitDriver instead for FirefoxDriver while starting webdriver. This is headless browser setup. Details can be found here.

Difference between Spring MVC and Spring Boot

Here is some main point which differentiate Spring, Spring MVC and Spring Boot :

Spring :

  1. Main Difference is "Test-ability".
  2. Spring come with the DI and IOC. Through which all hard-work done by system we don't need to do any kind of work(like, normally we define object of class manually but through Di we just annotate with @Service or @Component - matching class manage those).
  3. Through @Autowired annotation we easily mock() it at unit testing time.
  4. Duplication and Plumbing code. In JDBC we writing same code multiple time to perform any kind of database operation Spring solve that issue through Hibernate and ORM.
  5. Good Integration with other frameworks. Like Hibernate, ORM, Junit & Mockito.

Spring MVC

  1. Spring MVC framework is module of spring which provide facility HTTP oriented web application development.
  2. Spring MVC have clear code separation on input logic(controller), business logic(model), and UI logic(view).
  3. Spring MVC pattern help to develop flexible and loosely coupled web applications.
  4. Provide various hard coded way to customise your application based on your need.

Spring Boot :

  1. Create of Quick Application so that, instead of manage single big web application we divide them individually into different Microservices which have their own scope & capability.
  2. Auto Configuration using Web Jar : In normal Spring there is lot of configuration like DispatcherServlet, Component Scan, View Resolver, Web Jar, XMLs. (For example if I would like to configure datasource, Entity Manager Transaction Manager Factory). Configure automatically when it's not available using class-path.
  3. Comes with Default Spring Starters, which come with some default Spring configuration dependency (like Spring Core, Web-MVC, Jackson, Tomcat, Validation, Data Binding, Logging). Don't worry about versioning issue as well.

(Evolution like : Spring -> Spring MVC -> Spring Boot, So newer version have the compatibility of old version features.) Note : It doesn't contain all point.

What is the difference between null=True and blank=True in Django?

Here, is the main difference of null=True and blank=True:

The default value of both null and blank is False. Both of these values work at field level i.e., whether we want to keep a field null or blank.

null=True will set the field’s value to NULL i.e., no data. It is basically for the databases column value.

date = models.DateTimeField(null=True)

blank=True determines whether the field will be required in forms. This includes the admin and your own custom forms.

title = models.CharField(blank=True) // title can be kept blank. In the database ("") will be stored. null=True blank=True This means that the field is optional in all circumstances.

epic = models.ForeignKey(null=True, blank=True)
// The exception is CharFields() and TextFields(), which in Django are never saved as NULL. Blank values a

How to display list items as columns?

You can use flex as below:

.parent-container {
    display: flex;
    flex-direction: column;
    flex-wrap: wrap;
    max-height: 100px;
}

Adjust max-height property as per need to generate another columns

What is the (best) way to manage permissions for Docker shared volumes?

The same as you, I was looking for a way to map users/groups from host to docker containers and this is the shortest way I've found so far:

  version: "3"
    services:
      my-service:
        .....
        volumes:
          # take uid/gid lists from host
          - /etc/passwd:/etc/passwd:ro
          - /etc/group:/etc/group:ro
          # mount config folder
          - path-to-my-configs/my-service:/etc/my-service:ro
        .....

This is an extract from my docker-compose.yml.

The idea is to mount (in read-only mode) users/groups lists from the host to the container thus after the container starts up it will have the same uid->username (as well as for groups) matchings with the host. Now you can configure user/group settings for your service inside the container as if it was working on your host system.

When you decide to move your container to another host you just need to change user name in service config file to what you have on that host.

Android Studio marks R in red with error message "cannot resolve symbol R", but build succeeds

It has also worked for me by doing manually cleaning the folder .idea/libraries and clicking afterward on "Sync Project with Gradle Files" solves the problem. Apparently this Sync does not remove elements, but keep the old ones and add the current ones. Probably a bug to report :)

Format Instant to String

DateTimeFormatter.ISO_INSTANT.format(Instant.now())

This saves you from having to convert to UTC. However, some other language's time frameworks may not support the milliseconds so you should do

DateTimeFormatter.ISO_INSTANT.format(Instant.now().truncatedTo(ChronoUnit.SECONDS))

TortoiseGit save user authentication / credentials

None of the above answers worked for me using git version 1.8.3.msysgit.0 and TortoiseGit 1.8.4.0.

In my particular situation, I have to connect to the remote git repo over HTTPS, using a full blown e-mail address as username. In this situation, wincred did not appear to work.

Using the email address as a part of the repo URL also did not work, as the software seems to be confused by the double appearance of the '@' character in the URL.

I did manage to overcome the problem using winstore. Here is what I did:

This will copy the git-credential-winstore.exe to a local directory and add two lines to your global .gitconfig. You can verify this by examining your global .gitconfig. This is easiest done via right mouse button on a folder, "TortoiseGit > Settings > Git > Edit global .gitconfig". The file should contain two lines like:

    [credential]
        helper = !'C:\\Users\\yourlogin\\AppData\\Roaming\\GitCredStore\\git-credential-winstore.exe'
  • No other TortoiseGit settings are needed under "Network" or "Credential". In particular: the "Credential helper" pull down menu under "Credential" will have gone blank as a result of these configuration lines, since TortoiseGit does not recognize the new helper. Do not set the pull down menu to another value or the global .gitconfig will be overwritten with an incorrect value! (*)

You are now ready to go:

  • Try to pull from the remote repository. You will notice an authentication popup asking your username and password, the popup should be visually different from the default TortoiseGit popup. This is a good sign and means winstore works. Enter the correct authentication and the pull should succeed.
  • Try the same pull again, and your username and password should no longer be asked.

Done! Enjoy your interactions with the remote repo while winstore takes care of the authentication.

(*) Alternatively, if you don't like the blank selection in the TortoiseGit Credential settings helper pull down menu, you can use the "Advanced" option:

  • Go to "TortoiseGit > Settings > Credential"
  • Select Credential helper "Advanced"
  • Click on the "G" (for global) under Helpers
  • Enter the Helper path as below. Note: a regular Windows path notation (e.g. "C:\Users...") will not work here, you have to replicate the exact line that installing winstore created in the global .gitconf without the "helper =" bit.

    !'C:\\Users\\yourlogin\\AppData\\Roaming\\GitCredStore\\git-credential-winstore.exe'
    
  • Click the "Add New/Save" button

Why is January month 0 in Java Calendar?

Probably because C's "struct tm" does the same.

Logging POST data from $request_body

This solution works like a charm (updated in 2017 to honor that log_format needs to be in the http part of the nginx config):

log_format postdata $request_body;

server {
    # (...)

    location = /post.php {
       access_log  /var/log/nginx/postdata.log  postdata;
       fastcgi_pass php_cgi;
    }
}

I think the trick is making nginx believe that you will call a cgi script.

NGINX to reverse proxy websockets AND enable SSL (wss://)?

for .net core 2.0 Nginx with SSL

location / {
    # redirect all HTTP traffic to localhost:8080
    proxy_pass http://localhost:8080;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    # WebSocket support
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $http_connection;
}

This worked for me

What's onCreate(Bundle savedInstanceState)

onCreate(Bundle) is called when the activity first starts up. You can use it to perform one-time initialization such as creating the user interface. onCreate() takes one parameter that is either null or some state information previously saved by the onSaveInstanceState.

Adding system header search path to Xcode

To use quotes just for completeness.

"/Users/my/work/a project with space"/**

If not recursive, remove the /**

How to mock a final class with mockito

For us, it was because we excluded mockito-inline from koin-test. One gradle module actually needed this and for reason only failed on release builds (debug builds in the IDE worked) :-P

'do...while' vs. 'while'

I am programming about 12 years and only 3 months ago I have met a situation where it was really convenient to use do-while as one iteration was always necessary before checking a condition. So guess your big-time is ahead :).

What is the difference between i++ and ++i?

Just for the record, in C++, if you can use either (i.e.) you don't care about the ordering of operations (you just want to increment or decrement and use it later) the prefix operator is more efficient since it doesn't have to create a temporary copy of the object. Unfortunately, most people use posfix (var++) instead of prefix (++var), just because that is what we learned initially. (I was asked about this in an interview). Not sure if this is true in C#, but I assume it would be.

Open local folder from link

Local Explorer - File Manager on web browser extention can solve for chrome

but still some encoding problems

Submitting the value of a disabled input field

I wanna Disable an Input Field on a form and when i submit the form the values from the disabled form is not submitted.

Use Case: i am trying to get Lat Lng from Google Map and wanna Display it.. but dont want the user to edit it.

You can use the readonly property in your input field

<input type="text" readonly="readonly" />

PHPDoc type hinting for array of objects?

I've found something which is working, it can save lives !

private $userList = array();
$userList = User::fetchAll(); // now $userList is an array of User objects
foreach ($userList as $user) {
   $user instanceof User;
   echo $user->getName();
}

How do you plot bar charts in gnuplot?

plot "data.dat" using 2: xtic(1) with histogram

Here data.dat contains data of the form

title 1
title2 3
"long title" 5

Difference between Key, Primary Key, Unique Key and Index in MySQL

Primary key does not allow NULL values, but unique key allows NULL values.

We can declare only one primary key in a table, but a table can have multiple unique keys (column assign).

AWK: Access captured group from line pattern

This is something I need all the time so I created a bash function for it. It's based on glenn jackman's answer.

Definition

Add this to your .bash_profile etc.

function regex { gawk 'match($0,/'$1'/, ary) {print ary['${2:-'0'}']}'; }

Usage

Capture regex for each line in file

$ cat filename | regex '.*'

Capture 1st regex capture group for each line in file

$ cat filename | regex '(.*)' 1

Python constructors and __init__

There is no function overloading in Python, meaning that you can't have multiple functions with the same name but different arguments.

In your code example, you're not overloading __init__(). What happens is that the second definition rebinds the name __init__ to the new method, rendering the first method inaccessible.

As to your general question about constructors, Wikipedia is a good starting point. For Python-specific stuff, I highly recommend the Python docs.

how to activate a textbox if I select an other option in drop down box

Below is the core JavaScript you need to write:

<html> 
<head>  
<script type="text/javascript">
function CheckColors(val){
 var element=document.getElementById('color');
 if(val=='pick a color'||val=='others')
   element.style.display='block';
 else  
   element.style.display='none';
}

</script> 
</head>
<body>
  <select name="color" onchange='CheckColors(this.value);'> 
    <option>pick a color</option>  
    <option value="red">RED</option>
    <option value="blue">BLUE</option>
    <option value="others">others</option>
  </select>
<input type="text" name="color" id="color" style='display:none;'/>
</body>
</html>

Laravel 5.1 - Checking a Database Connection

You can use this query for checking database connection in laravel:

$pdo = DB::connection()->getPdo();

if($pdo)
   {
     echo "Connected successfully to database ".DB::connection()->getDatabaseName();
   } else {
     echo "You are not connected to database";
   }

For more information you can checkout this page https://laravel.com/docs/5.0/database.

Asp.net - Add blank item at top of dropdownlist

You can use AppendDataBoundItems=true to easily add:

<asp:DropDownList ID="drpList" AppendDataBoundItems="true" runat="server">
    <asp:ListItem Text="" Value="" />
</asp:DropDownList>

How to remove jar file from local maven repository which was added with install:install-file?

  1. cd ~/.m2
  2. git init
  3. git commit -am "some comments"
  4. cd /path/to/your/project
  5. mvn install
  6. cd ~/.m2
  7. git reset --hard

How do I specify "not equals to" when comparing strings in an XSLT <xsl:if>?

If you want to compare to a string literal you need to put it in (single) quotes:

<xsl:if test="Count != 'N/A'">

how to get program files x86 env variable?

On a Windows 64 bit machine, echo %programfiles(x86)% does print C:\Program Files (x86)

How to install latest version of git on CentOS 7.x/6.x

My personal preference is to build rpm packages for CentOS when installing non-standard software and replacing distributed components. For this I recommend that you use Mock to create a clean build environment.

The procedure is:

  1. Obtain the source RPMS or a suitable SPEC file and pristine source tarball. In this case one may find source RPM packages for git2X for CentOS-6 at: http://dl.iuscommunity.org/pub/ius/archive/CentOS/6/SRPMS/. Packages for other CentOS releases are also available.

  2. Install the necessary support software:

    yum install epel-release  # you need this for mock
    yum install rpm-build
    yum install redhat-rpm-config
    yum install rpmdevtools
    yum install mock
    
  3. Add a rpm build user account (do not build as root or as a real user - security issues will come back to bite you).

    sudo adduser builder --home-dir /home/builder \
    --create-home --user-group --groups mock \
    --shell /bin/bash --comment "rpm package builder"
    
  4. Next we need a build environment.

    su -l builder
    rpmdev-setuptree
    

    This produces the following directory structure:

    ~
    +-- rpmbuild
        +-- BUILD
        +-- RPMS
        +-- SOURCES
        +-- SPECS
        +-- SRPMS
    
  5. We are using a prepared SRPMS so the SOURCES tarballs can be ignored for this case and we can go direct to SRPMS.

    wget http://dl.iuscommunity.org/pub/ius/archive/CentOS/6/SRPMS/git2u-2.5.3-1.ius.centos6.src.rpm \
    -O ~/rpmbuild/SRPMS/git2u-2.5.3-1.ius.centos6.src.rpm
    
  6. Configure mock (as root)

    cd /etc/mock
    rm default.cfg
    ln -s epel-6-x86_64.cfg default.cfg
    vim default.cfg
    

    Disable the beta repos. Enable the base and update repos.

  7. Initialize the build tree (/var/lib/mock is default)

    mock --init
    
  8. If we were building from SOURCES then this is where we would employ the SPEC file and use mock --buildsrpm . . .. But in this case we go directly to the binary build step:

    mock --no-clean --rebuild ~/rpmbuild/SRPMS/git2u-2.5.3-1.ius.centos6.src.rpm
    

    This will resolve the build dependencies and download them (about 95 or so packages) into the clean build root. It will then extract the sources and build the binary from the provided SRPM and leave it in /var/lib/mock/epel-6-x86_64/result; or in whatever custom build root location and architecture you provided. It will take a long time. There is a lot to this package; particularly documentation.

  9. If all goes well then you should end up with a suit of RPM packages suitable for installation in place of the distro version. This is what I ended up with:

    ll /var/lib/mock/epel-6-x86_64/result
    total 34996
    -rw-rw-r--. 1 byrnejb mock   448455 Oct 30 10:09 build.log
    -rw-rw-r--. 1 byrnejb mock    52464 Oct 30 10:09 emacs-git2u-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock    47228 Oct 30 10:09 emacs-git2u-el-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock  8474478 Oct 30 09:57 git2u-2.5.3-1.ius.el6.src.rpm
    -rw-rw-r--. 1 byrnejb mock  8877584 Oct 30 10:09 git2u-2.5.3-1.ius.el6.x86_64.rpm
    -rw-rw-r--. 1 byrnejb mock    27284 Oct 30 10:09 git2u-all-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock    27800 Oct 30 10:09 git2u-bzr-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock   112564 Oct 30 10:09 git2u-cvs-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock   436176 Oct 30 10:09 git2u-daemon-2.5.3-1.ius.el6.x86_64.rpm
    -rw-rw-r--. 1 byrnejb mock 15858600 Oct 30 10:09 git2u-debuginfo-2.5.3-1.ius.el6.x86_64.rpm
    -rw-rw-r--. 1 byrnejb mock    60556 Oct 30 10:09 git2u-email-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock   274888 Oct 30 10:09 git2u-gui-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock    79176 Oct 30 10:09 git2u-p4-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock   483132 Oct 30 10:09 git2u-svn-2.5.3-1.ius.el6.x86_64.rpm
    -rw-rw-r--. 1 byrnejb mock   173732 Oct 30 10:09 gitk2u-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock   115692 Oct 30 10:09 gitweb2u-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock    57196 Oct 30 10:09 perl-Git2u-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock    89900 Oct 30 10:09 perl-Git2u-SVN-2.5.3-1.ius.el6.noarch.rpm
    -rw-rw-r--. 1 byrnejb mock   101026 Oct 30 10:09 root.log
    -rw-rw-r--. 1 byrnejb mock      980 Oct 30 10:09 state.log
    
  10. Install using yum or rpm.

    You will require git2u-2.5.3-1.ius.el6.x86_64.rpm at a minimum and such additional support packages as it requires (perl-Git2u-2.5.3-1.ius.el6.noarch.rpm) or you desire.

    This build has a cyclic dependency: git2u-2.5.3-1.ius.el6.x86_64.rpm depends upon perl-Git2u-2.5.3-1.ius.el6.noarch.rpm and perl-Git2u-2.5.3-1.ius.el6.noarch.rpm depends upon git2u-2.5.3-1.ius.el6.x86_64.rpm. A straight install with rpm will thus fail.

    There are two ways of dealing with it:

    • Install both at the same time via yum:

      yum localinstall \
        git2u-2.5.3-1.ius.el6.x86_64.rpm \
        perl-Git2u-2.5.3-1.ius.el6.noarch.rpm`
      
    • Setup a local yum repo.

      I am including my LocalFile.repo file below as it contains instructions on how to do this and provides the necessary repo file at the same time.

cat /etc/yum.repos.d/LocalFile.repo
# LocalFile.repo
#
#  This repo is used with a local filesystem repo.
#
# To use this repo place the rpm package in /root/RPMS/yum.repo/Packages.
# Then run: createrepo --database --update /root/RPMS/yum.repo.
#
# To use:
#  yum --enablerepo=localfile [command]
#  
# or to use only ONLY this repo, do this:
#
#  yum --disablerepo=\* --enablerepo=localfile [command]

[localfile]
baseurl=file:///root/RPMS/yum.repo
name=CentOS-$releasever - Local Filesystem repo

# Before persistently enabling this repo see the priority note below.
enabled=0
gpgcheck=0

# When this repo is enabled all packages in repos with priority>5
# will not be updated even when they have a more recent version.
# Be careful with this.
priority=5

You also may be required to manually pre-install additional dependency packages such as perl-TermReadKey available from the usual repositories.

Getting query parameters from react-router hash fragment

update 2017.12.25

"react-router-dom": "^4.2.2"

url like

BrowserHistory: http://localhost:3000/demo-7/detail/2?sort=name

HashHistory: http://localhost:3000/demo-7/#/detail/2?sort=name

with query-string dependency:

this.id = props.match.params.id;
this.searchObj = queryString.parse(props.location.search);
this.from = props.location.state.from;

console.log(this.id, this.searchObj, this.from);

results:

2 {sort: "name"} home


"react-router": "^2.4.1"

Url like http://localhost:8080/react-router01/1?name=novaline&age=26

const queryParams = this.props.location.query;

queryParams is a object contains the query params: {name: novaline, age: 26}

Cannot connect to the Docker daemon on macOS

i simply had to run spotlight search and execute the Docker application under /Applications folder which brew cask install created. Once this was run it asked to complete installation. I was then able to run docker ps

Can an AJAX response set a cookie?

Also check that your server isn't setting secure cookies on a non http request. Just found out that my ajax request was getting a php session with "secure" set. Because I was not on https it was not sending back the session cookie and my session was getting reset on each ajax request.

Check if program is running with bash shell script?

PROCESS="process name shown in ps -ef"
START_OR_STOP=1        # 0 = start | 1 = stop

MAX=30
COUNT=0

until [ $COUNT -gt $MAX ] ; do
        echo -ne "."
        PROCESS_NUM=$(ps -ef | grep "$PROCESS" | grep -v `basename $0` | grep -v "grep" | wc -l)
        if [ $PROCESS_NUM -gt 0 ]; then
            #runs
            RET=1
        else
            #stopped
            RET=0
        fi

        if [ $RET -eq $START_OR_STOP ]; then
            sleep 5 #wait...
        else
            if [ $START_OR_STOP -eq 1 ]; then
                    echo -ne " stopped"
            else
                    echo -ne " started"
            fi
            echo
            exit 0
        fi
        let COUNT=COUNT+1
done

if [ $START_OR_STOP -eq 1 ]; then
    echo -ne " !!$PROCESS failed to stop!! "
else
    echo -ne " !!$PROCESS failed to start!! "
fi
echo
exit 1

Creating a singleton in Python

This answer is likely not what you're looking for. I wanted a singleton in the sense that only that object had its identity, for comparison to. In my case it was being used as a Sentinel Value. To which the answer is very simple, make any object mything = object() and by python's nature, only that thing will have its identity.

#!python
MyNone = object()  # The singleton

for item in my_list:
    if item is MyNone:  # An Example identity comparison
        raise StopIteration

HTML list-style-type dash

You can just set li::marker like so:

li::marker {
   content: '- ';
}