Tutorial by Examples: w

Environment variables can be defined before the meteor call, like so: PORT=4000 meteor NODE_ENV="staging" meteor

Downloading a file from the internet is a very common task required by almost every application your likely to build. To accomplish this, you can use the "System.Net.WebClient" class. The simplest use of this, using the "using" pattern, is shown below: using (var webClient = n...

Method 1 Gson gson = new Gson(); String json = "[ \"Adam\", \"John\", \"Mary\" ]"; Type type = new TypeToken<List<String>>(){}.getType(); List<String> members = gson.fromJson(json, type); Log.v("Members", members.toString());...

Angular has some magic under its hood. it enables binding DOM to real js variables. Angular uses a loop, named the "digest loop", which is called after any change of a variable - calling callbacks which update the DOM. For example, the ng-model directive attaches a keyup eventListener to...

Implementing two-way-data-binding, to achieve the result from the previous example, could be done with two core functions: $digest is called after a user interaction (binding DOM=>variable) $watch sets a callback to be called after variable changes (binding variable=>DOM) note: this is ...

A minimal Dockerfile looks like this: FROM alpine CMD ["echo", "Hello StackOverflow!"] This will instruct Docker to build an image based on Alpine (FROM), a minimal distribution for containers, and to run a specific command (CMD) when executing the resulting image. Build an...

Let's swap the implementation of methodOne() and methodTwo() in our TestSwizzling class: class TestSwizzling : NSObject { dynamic func methodOne()->Int{ return 1 } } extension TestSwizzling { //In Objective-C you'd perform the swizzling in load(), //but t...

When results need to have some logic applied 'on the fly' one can use CASE statement to implement it. SELECT CASE WHEN Col1 < 50 THEN 'under' ELSE 'over' END threshold FROM TableName also can be chained SELECT CASE WHEN Col1 < 50 THEN 'under' WHEN Col1 > 50 AND Col1 ...

Sometimes when tables are used mostly (or only) for reads, indexing does not help anymore and every little bit counts, one might use selects without LOCK to improve performance. SQL Server SELECT * FROM TableName WITH (nolock) MySQL SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;...

Ensure you have the latest nodeJS LTS installed Open command prompt and type $ npm install -g nativescript In the command prompt type $ @powershell -NoProfile -ExecutionPolicy Bypass -Command "iex ((new-object net.webclient).DownloadString('https://www.nativescript.org/setup/win'))" - ...

In the following example, the greet function inside Greeter module is run in a separate process: defmodule Greeter do def greet do IO.puts "Hello programmer!" end end iex> spawn(Greeter, :greet, []) Hello #PID<0.122.0> Here #PID<0.122.0> is the ...

The following example declares a piece of code to be written in Racket, and then prints the string Hello, world. #lang racket "Hello, world!" Racket code can either be run directly from the command line or on the DrRacket IDE. Typing racket on the command line will start a REPL, and t...

First you need to install and start your Redis server, check the link below that can help you to install redis on you server or local machine. Installation and Setup Now open your command prompt and run command redis-cli : To save first set >SET 'keyname' then 'value' 127.0.0.1:6379> SET h...

To change password of current user just type: sudo passwd It will ask you to enter your current password: [sudo] password for <user>: And then you will be asked to enter new password: Enter new UNIX password: And finally you will be asked to re-enter your password: Retype new UNIX...

Swift //Swift let viewController = UIViewController() let navigationController = UINavigationController(rootViewController: viewController) //Objective-C UIViewController *viewController = [[UIViewController alloc] init]; UINavigationController *navigationController = [[UINavigationControlle...

//Swift let fooViewController = UIViewController() navigationController?.pushViewController(fooViewController, animated: true) //Objective-C UIViewController *fooViewController = [[UIViewController alloc] init]; [navigationController pushViewController:fooViewController animated:YES];

As we know that we should use synchronized keyword to make execution of a method or block exclusive. But few of us may not be aware of one more important aspect of using synchronized and volatile keyword: apart from making a unit of code atomic, it also provides read / write barrier. What is this re...

If you've got multiple implementations of the same interface, Spring can autowire them all into a collection object. I'm going to use an example using a Validator pattern1 Foo Class: public class Foo { private String name; private String emailAddress; private String errorMessage;...

If you have both Python 3 and Python 2 installed, you can specify which version of Python you would like pip to use. This is useful when packages only support Python 2 or 3 or when you wish to test with both. If you want to install packages for Python 2, run either: pip install [package] or: p...

Corner radius for all 4 edges: UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) cornerRadius: 11]; [UIColor.grayColor setFill]; [rectanglePath fill]; Corner radius for top-left edge: UIBezierPath* rectanglePath = [UIBezierPath bezierPat...