Tutorial by Examples: st

Registering for (Non Interactive) Push Notification

The logic of registering for push notification is recommended to be added in AppDelegate.swift as the callback functions (success, failure) will be called their. To register just do the following: let application = UIApplication.sharedApplication() let settings = UIUserNotificationSettings(forType...

iOS • Push Notifications

Closing a stream

A stream is closed by sending a closing </stream> tag. After the closing stream tag is sent, no more data should be sent on the stream (even in response to data received from the other party). Before closing the connection, the sending entity should wait for a response </stream> tag to g...

xmpp • Stream Negotiation

Starting a stream

Once a TCP connection is established, the initial stream header is sent by the initiating entity. Similarly, whenever a stream restart is required (eg. after negotiating a security layer such as TLS) a stream header must also be sent: <?xml version='1.0'?> <stream:stream from='juliet...

xmpp • Stream Negotiation

Installation or Setup

To install dplyr simply type in the R console. install.packages("dplyr") And then to load dplyr, type library("dplyr") It's also possible to install the latest development version from Github with: if (packageVersion("devtools") < 1.6) { install.packages...

dplyr • Getting started with dplyr

Installation or Setup

Python Windows The easiest way to install GTK3 for Python is by using PyGObject for Windows. It offers an installer that installs most things you need to develop GTK appilcations. The number of options the PyGObject installer offers can be daunting, but for most GTK projects the only option you h...

gtk3 • Getting started with gtk3

Prevent container from stopping when no commands are running

A container will stop if no command is running on the foreground. Using the -t option will keep the container from stopping, even when detached with the -d option. docker run -t -d debian bash

Docker • Running containers

Stopping a container

docker stop mynginx Additionally, the container id can also be used to stop the container instead of its name. This will stop a running container by sending the SIGTERM signal and then the SIGKILL signal if necessary. Further, the kill command can be used to immediately send a SIGKILL or any ot...

Docker • Running containers

Temporary Jupyter Notebook hosted by Rackspace

Jupyter Notebooks are an interactive, browser-based development environment. They were originally developed to run computation python and as such play very well with numpy. To try numpy in a Jupyter notebook without fully installing either on one's local system Rackspace provides free temporary note...

numpy • Getting started with numpy

Use what the language offers: the if/else construct.

Well, if you want a switch/case construct, the most straightforward way to go is to use the good old if/else construct: def switch(value): if value == 1: return "one" if value == 2: return "two" if value == 42: return "the answer to...

Python Language • Alternatives to switch statement from other languages

Installation or Setup

Chart.js can be included in several different ways: NPM Run the following command on your NPM project directory npm install chart.js --save CDN Include a script tag in your HTML linking to the chart.js CDN <html> <body> <script type="text/javascript" s...

chart.js • Getting started with chart.js

Using character constants instead of string literals, and vice versa

In C, character constants and string literals are different things. A character surrounded by single quotes like 'a' is a character constant. A character constant is an integer whose value is the character code that stands for the character. How to interpret character constants with multiple charac...

C Language • Common pitfalls

Accessing Instance/Class Variables in Singleton Classes

Singleton classes share their instance/class variables with their object. class Example @@foo = :example end def Example.foo class_variable_get :@@foo end Example.foo #=> :example class Example def initialize @foo = 1 end def foo @foo end end e = Ex...

Ruby Language • Singleton Class

Delete a range of lines into a named register

In Normal, type the following to delete a range of lines into a named register :10,20d a This will delete lines 10,20 in register "a. We can verify this by typing :reg This will show the text that was delete in register "a. To paste the contents in "a, just type "ap ...

vim • Vim Registers

StackOverflowError & recursion to loop

If a recursive call goes "too deep", this results in a StackOverflowError. Java allocates a new frame for every method call on its thread's stack. However, the space of each thread's stack is limited. Too many frames on the stack leads to the Stack Overflow (SO). Example public static vo...

Java Language • Recursion

Set a custom date format

Default date format: "mm/dd/yy" The following example shows how you can set the date format in initialization with the dateFormat option. <input type="text" id="datepicker"> <script> $("#datepicker").datepicker({ dateFormat: "...

jQuery UI Library • Datepicker

Getting started on iOS

Prerequisites Create a new project and add an iOS app to that project in the Firebase Console. Download and include GoogleServices-Info.plist in your application. Add Firebase Storage to your app Add the following dependency to your project's Podfile: pod 'Firebase/Storage' Run pod insta...

firebase • Storage

Destructuring assignment

In assignments, you can split an Iterable into values using the "unpacking" syntax: Destructuring as values a, b = (1, 2) print(a) # Prints: 1 print(b) # Prints: 2 If you try to unpack more than the length of the iterable, you'll get an error: a, b, c = [1] # Raises: ValueError:...

Python Language • List destructuring (aka packing and unpacking)

Matching an exact string

let fetchRequest = NSFetchRequest(entityName: "Foo") var thePredicate: NSPredicate? thePredicate = NSPredicate(format: "message == 'example'") The entity Foo has a message string attribute

core-data • Using Predicates

switch () Statements

switch statements are useful when you want to have your program do many different things according to the value of a particular test variable. An example usage of switch statement is like this: int a = 1; switch (a) { case 1: puts("a is 1"); break; case 2: puts("...

C Language • Selection Statements

Using Paste

$ gunzip -c input.fastq.gz | paste - - - - | head @IL31_4368:1:1:996:8507/2 TCCCTTACCCCCAAGCTCCATACCCTCCTAATGCCCACACCTCTTACCTTAGGA + FFCEFFFEEFFFFFFFEFFEFFFEFCFC<EEFEFFFCEFF<;EEFF=FEE?FCE @IL31_4368:1:1:996:21421/2 CAAAAACTTTCACTTTACCTGCCGGGTTTCCCAGTTTACATTCCACTGTTTGAC + ...

bioinformatics • Linearizing a fastq file