Tutorial by Examples: 5

How to install Ruby on Rails 5 on RVM

RVM is a great tool to manage your ruby versions and set up your working environment. Assuming you already have RVM installed, to get the latest version of ruby, which is needed for these examples, open a terminal and run: $ rvm get stable $ rvm install ruby --latest Check your ruby version by...

Ruby on Rails • Rails 5

PHP5 SuperGlobals

Below are the PHP5 SuperGlobals $GLOBALS $_REQUEST $_GET $_POST $_FILES $_SERVER $_ENV $_COOKIE $_SESSION $GLOBALS: This SuperGlobal Variable is used for accessing globals variables. <?php $a = 10; function foo(){ echo $GLOBALS['a']; } //Which will print 10 Glo...

PHP • Superglobal Variables PHP

Upgrading from Rails 4.2 to Rails 5.0

Note: Before upgrading your Rails app, always make sure to save your code on a version control system, such as Git. To upgrade from Rails 4.2 to Rails 5.0, you must be using Ruby 2.2.2 or newer. After upgrading your Ruby version if required, go to your Gemfile and change the line: gem 'rails', '...

Ruby on Rails • Upgrading Rails

ES2015 Syntax

'use strict'; // This is an example of a /api/controllers/HomeController.js module.exports = { // This is the index action and the route is mapped via /config/routes.js index(req, res) { // Return a view without view model data // This typically will return the view defined at /v...

sails.js • Controllers

Using ES2015 generators with co.js

'use strict'; const co = require('co'); module.exports = { // This is the index action and the route is mapped via /config/routes.js index(req, res) { co(function* index() { // Return a view without view model data // This typically will return the view defined at /vie...

sails.js • Controllers

Print lines 5 to 10

perl -ne'print if 5..10' file.txt

Perl Language • Perl one-liners

IEnumerable to Dictionary (≥ .NET 3.5)

Create a Dictionary<TKey, TValue> from an IEnumerable<T>: using System; using System.Collections.Generic; using System.Linq; public class Fruits { public int Id { get; set; } public string Name { get; set; } } var fruits = new[] { new Fruits { Id = 8 , Nam...

.NET Framework • Dictionaries

Error code 1215: Cannot add foreign key constraint

This error occurs when tables are not adequately structured to handle the speedy lookup verification of Foreign Key (FK) requirements that the developer is mandating. CREATE TABLE `gtType` ( `type` char(2) NOT NULL, `description` varchar(1000) NOT NULL, PRIMARY KEY (`type`) ) ENGINE=InnoD...

MySQL • Error codes

VARCHAR(255) -- or not

Suggested max len First, I will mention some common strings that are always hex, or otherwise limited to ASCII. For these, you should specify CHARACTER SET ascii (latin1 is ok) so that it will not waste space: UUID CHAR(36) CHARACTER SET ascii -- or pack into BINARY(16) country_code CHAR(2) CHAR...

MySQL • Data Types

Enabling CORS in Asp.Net 5 for all domains and methods

public void ConfigureServices(IServiceCollection services) { services.AddCors(o => o.AddPolicy("MyPolicy", builder => { builder.AllowAnyOrigin() .AllowAnyMethod() .AllowAnyHeader(); })); // ... } public void Configur...

asp.net-web-api • ASP.NET WEB API CORS Enabling

Enabling CORS in Asp.Net 5 for specific domains and methods

public void ConfigureServices(IServiceCollection services) { services.AddMvc(); services.AddCors(); services.ConfigureCors(options => options.AddPolicy("AllowSpecific", p => p.WithOrigins("http://localhost:1233") ...

asp.net-web-api • ASP.NET WEB API CORS Enabling

Simple example (Java version < 1.5)

This example will call the windows calculator. It's important to notice that the exit code will vary accordingly to the program/script that is being called. package process.example; import java.io.IOException; public class App { public static void main(String[] args) { try { ...

Java Language • Process

HTML 5 Doctype

HTML5 is not based on SGML, and therefore does not require a reference to a DTD. HTML 5 Doctype declaration: <!DOCTYPE html> Case Insensitivity Per the W3.org HTML 5 DOCTYPE Spec: A DOCTYPE must consist of the following components, in this order: A string that is an ASCII case-inse...

HTML • Doctypes

Eclipse as Play IDE - Java, Play 2.4, 2.5

Introduction Play has several plugins for different IDE-s. The eclipse plugin allows to transform a Play application into a working eclipse project with the command activator eclipse. Eclipse plugin may be set per project or globally per sbt user. It depends on team work, which approach should be u...

playframework • Setting up your preferred IDE

Get Historic Time from NSDate (eg: 5s ago, 2m ago, 3h ago)

This can be used in various chat applications, rss feeds, and social apps where you need to have latest feeds with timestamps: Objective-C - (NSString *)getHistoricTimeText:(NSDate *)since { NSString *str; NSTimeInterval interval = [[NSDate date] timeIntervalSinceDate:since]; if(in...

iOS • NSDate

Php 5.6 with Apache 2 Server on Ubuntu 16.04

This tutorial will guide you through the process from scratch. Please note some preliminary notes about this particular setup, useful in case that you already have some requested package: Is needed a version of php >=5.0 (I had troubles with php 7.0) Is requested any version of perl Is need...

Ubuntu • Apache Server

1045 Access denied

See discussions in "GRANT" and "Recovering root password".

MySQL • Error codes

126, 127, 134, 144, 145

When you try access the records from MySQL database, you may get these error messages. These error messages occurred due to corruption in MySQL database. Following are the types MySQL error code 126 = Index file is crashed MySQL error code 127 = Record-file is crashed MySQL error code 134 = Recor...

MySQL • Error codes

126, 1054, 1146, 1062, 24

(taking a break) With the inclusion of those 4 error numbers, I think this page will have covered about 50% of the typical errors users get. (Yes, this 'Example' needs revision.) 24 Can't open file (Too many open files) open_files_limit comes from an OS setting. table_open_cache needs to be les...

MySQL • Error codes

Analyzing 50 billion Wikipedia pageviews in 5 seconds (BigQuery beginner tutorial)

Hi everyone! This is a demo I love running for people that get started with BigQuery. So let's run some simple queries to get you started. Setup You will need a Google Cloud project: Go to http://bigquery.cloud.google.com/. If it tells you to create a project, follow the link to create a proje...

google-bigquery • Getting started with google-bigquery