Tutorial by Examples: di

Loading External Images/SWFs With The Loader

Create a Loader object: var loader:Loader = new Loader(); //import Add listeners on the loader. Standard ones are complete and io/security errors loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadComplete); //when the loader is done loading, call this function loader.co...

ActionScript 3 • Loading External Files

Sending an SMS Message using Promises

Twilio's Node.JS API natively supports promises, allowing you to use promises when sending SMS messages (this example was taken and adapted directly from Twilio's API Docs). // Create an authenticated Twilio REST API client var twilio = require('twilio'); var client = new twilio.RestClient('ACCOU...

Twilio • Getting started with Twilio

Sending messages and MMS through Twilio

Twilio help build apps that communicate with everyone in the world. Voice & Video, Messaging and Authentication APIs for every application. You can get an API key for free. To send a message through Twilio, your application needs to make an HTTP POST request to Twilio with the following things...

Twilio • Send messages in Python

Display a map

<!DOCTYPE html> <html> <head> <meta charset='utf-8' /> <title></title> <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' /> <!-- find the latest library and style versions here: https://www.mapbox.com/m...

mapbox • Mapbox GL JS

Reading a file into a Buffer using streams

While reading content from a file is already asynchronous using the fs.readFile() method, sometimes we want to get the data in a Stream versus in a simple callback. This allows us to pipe this data to other locations or to process it as it comes in versus all at once at the end. const fs = require(...

Node.js • Filesystem I/O

Redirection

You can perform redirection in Rails routes as follows: 4.0 get '/stories', to: redirect('/posts') 4.0 match "/abc" => redirect("http://example.com/abc") You can also redirect all unknown routes to a given path: 4.0 match '*path' => redirect('/'), via: :get ...

Ruby on Rails • Routing

Download and install packages from repositories

Packages are collections of R functions, data, and compiled code in a well-defined format. Public (and private) repositories are used to host collections of R packages. The largest collection of R packages is available from CRAN. Using CRAN A package can be installed from CRAN using following code...

R Language • Installing packages

VendingMachineDecorator

Definition of Decorator as per Wikiepdia: The Decorator pattern can be used to extend (decorate) the functionality of a certain object statically, or in some cases at run-time, independently of other instances of the same class, provided some groundwork is done at design time. Decorator attach add...

Design patterns • Decorator pattern

Create a sample DataFrame from multiple collections using Dictionary

import pandas as pd import numpy as np np.random.seed(123) x = np.random.standard_normal(4) y = range(4) df = pd.DataFrame({'X':x, 'Y':y}) >>> df X Y 0 -1.085631 0 1 0.997345 1 2 0.282978 2 3 -1.506295 3

pandas • Creating DataFrames

Immediate Window

If you would like to test a line of macro code without needing to run an entire sub, you can type commands directly into the Immediate Window and hit ENTER to run the line. For testing the output of a line, you can precede it with a question mark ? to print directly to the Immediate Window. Altern...

excel-vba • Debugging and Troubleshooting

Checking existance of optional method implementations

if ([object respondsToSelector:@selector(someOptionalMethodInProtocol:)]) { [object someOptionalMethodInProtocol:argument]; }

Objective-C Language • Protocols

Deleting files and directories

Deleting files The unlink function deletes a single file and returns whether the operation was successful. $filename = '/path/to/file.txt'; if (file_exists($filename)) { $success = unlink($filename); if (!$success) { throw new Exception("Cannot delete $filename&qu...

PHP • File handling

Finding definition files

for typescript 2.x: definitions from DefinitelyTyped are available via @types npm package npm i --save lodash npm i --save-dev @types/lodash but in case if you want use types from other repos then can be used old way: for typescript 1.x: Typings is an npm package that can automatically insta...

TypeScript • Importing external libraries

Testing a JSON API implemented in Flask

This example assumes you know how to test a Flask app using pytest Below is an API that takes a JSON input with integer values a and b e.g. {"a": 1, "b": 2}, adds them up and returns sum a + b in a JSON response e.g. {"sum": 3}. # hello_add.py from flask import Flask...

Flask • Testing

Check Permissions of a File or Directory

fs.access() determines whether a path exists and what permissions a user has to the file or directory at that path. fs.access doesn't return a result rather, if it doesn't return an error, the path exists and the user has the desired permissions. The permission modes are available as a property on ...

Node.js • Filesystem I/O

Avoiding race conditions when creating or using an existing directory

Due to Node's asynchronous nature, creating or using a directory by first: checking for its existence with fs.stat(), then creating or using it depending of the results of the existence check, can lead to a race condition if the folder is created between the time of the check and the time of ...

Node.js • Filesystem I/O

Exporting and importing macros

Exporting a macro to allow other modules to use it: #[macro_export] // ^~~~~~~~~~~~~~~ Think of it as `pub` for macros. macro_rules! my_macro { (..) => {..} } Using macros from other crates or modules: #[macro_use] extern crate lazy_static; // ^~~~~~~~~~~~ Must add this in ord...

Rust • Macros

Variable Dimensions

:root { --W200: 200px; --W10: 10px; } .Bx2 { width: var(--W200); height: var(--W200); margin: var(--W10); }

CSS • Custom Properties (Variables)

Matching leading/trailing whitespace

Trailing spaces \s*$: This will match any (*) whitespace (\s) at the end ($) of the text Leading spaces ^\s*: This will match any (*) whitespace (\s) at the beginning (^) of the text Remarks \s is a common metacharacter for several RegExp engines, and is meant to capture whitespace characters (...

Regular Expressions • Matching Simple Patterns

Querying data nested in dictionaries

Get all ice cream cones that were ordered by people liking chocolate: IceCream.objects.filter(metadata__buyer__favorite_flavor='chocolate') See the note in the "Remarks" section about chaining queries.

Django • JSONField - a PostgreSQL specific field