Tutorial by Examples: d

In general, functions that operate on other functions, either by taking them as arguments or by returning them (or both), are called higher-order functions. A higher-order function is a function that can take another function as an argument. You are using higher-order functions when passing callbac...

:g/Hello/d Will delete every line containing the text "Hello". Important note: This is not the normal mode command d, this is the ex command :d. You can use the global command to apply normal mode keystrokes instead of ex commands by prepending normal or norm to the command. For exampl...

Modify your Gemfile to include the Devise gem: gem 'devise' Then update your gems with: $ bundle install Run the installers in your project: $ rails generate devise:install Then create your Devise model (e.g. User) with: $ rails generate devise User you'll need to set up the default ...

class CreateAuthenticationProviders < ActiveRecord::Migration def change create_table "authentication_providers", :force => true do |t| t.string "name" t.datetime "created_at", :null => false ...

class CreateUserAuthentications < ActiveRecord::Migration def change create_table "user_authentications", :force => true do |t| t.integer "user_id" t.integer "authentication_provider_id" t.string "uid&q...

has_many :users has_many :user_authentications

belongs_to :user belongs_to :authentication_provider serialize :params def self.create_from_omniauth(params, user, provider) token_expires_at = params['credentials']['expires_at'] ? Time.at(params['credentials']['expires_at']).to_datetime : nil create( user: user, ...

include OmniauthAttributesConcern has_many :user_authentications devise :omniauthable, :database_authenticatable, :registerable,:recoverable, :rememberable, :trackable def self.create_from_omniauth(params) self.send(params.provider,params) end

module OmniauthAttributesConcern extend ActiveSupport::Concern module ClassMethods Add Methods here end end In this concern we can create methods for each social media to fetch and store attributes. def twitter params (params['info']['email'] = "dummy#{SecureRan...

devise_for :users, controllers: {omniauth_callbacks: 'users/omniauth_callbacks'}

For Facebook config.omniauth :facebook, facebook_app_id, facebook_secret_key, :display => "popup", :scope => 'email,publish_actions', info_fields: 'email,name' For Twitter config.omniauth :twitter, twitter_app_id, twitter_secret_key, :display => "popup", :scope =&gt...

gem 'omniauth-oauth2' , '~> 1.3.1' gem 'omniauth' gem 'omniauth-facebook' gem 'omniauth-twitter' gem 'omniauth-gplus' gem 'omniauth-linkedin' Run the bundle install command, restart your server and off you go!

Moving away from a buffer with unsaved changes will cause this error: E37: No write since last change (add ! to override) You can disable this by adding set hidden to your .vimrc file. With this option set your changes will persist in the buffer, but will not be saved to disk.

If you don't want to use SQL server you can use Amazon's hosted Dynamo DB nosql database as a session store. You'll need the AWS SDK. To install this from the Visual Studio nuget package manager console use the following command Install-Package AWSSDK You can then configure your sessionState p...

This is a copy of the advanced function snippet from the Powershell ISE. Basically this is a template for many of the things you can use with advanced functions in Powershell. Key points to note: get-help integration - the beginning of the function contains a comment block that is set up to be ...

To work with ConstraintLayout, you need Android Studio Version 2.2 or newer and have at least version 32 (or higher) of Android Support Repository. Add the Constraint Layout library as a dependency in your build.gradle file: dependencies { compile 'com.android.support.constraint:constraint...

1. Print the Hadoop version hadoop version 2. List the contents of the root directory in HDFS hadoop fs -ls / 3. Report the amount of space used and available on currently mounted filesystem hadoop fs -df hdfs:/ 4. Count the number of directories,files and bytes under the paths tha...

For enabling Proguard configurations for your application you need to enable it in your module-level gradle file. You need to set the value of minifyEnabled to true. buildTypes { release { minifyEnabled true proguardFiles getDefaultProguardFile('proguard-android.t...

main.component.ts import {Component} from "@angular/core"; @Component({ selector: "main", template: ` <StackLayout> <TextField hint="some text"></TextField> <Button text="Click me" class="btn">...

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...