Leslie googya

Transactions

As your business logic gets complex you may need to implement transactions. The classic example is a bank funds transfer from account A to account B. If the withdrawal from account A fails then the deposit to account B should either never take place or be rolled back.

Basics

All the complexity is handled by ActiveRecord::Transactions. Any model class or instance has a method named .transaction. When called and passed a block, that block will be executed inside a database transaction. If there's an exception raised, the transaction will automatically be rolled back.

Example

Install

Either copy the aliases from the .gitconfig or run the commands in add-pr-alias.sh

Usage

Easily checkout local copies of pull requests from remotes:

git pr 4 - creates local branch pr/4 from the github upstream(if it exists) or origin remote and checks it out
git pr 4 someremote - creates local branch pr/4 from someremote remote and checks it out

用例子讲解 RxJS 5 的 Operators 。

原文链接：RxJS 5 Operators By Example by @btroncone

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

Redux higher order components

Sometimes we need to share props and behaviour between multiple components/containers. For that we can do a higher order component. Example:

Decorator component

Higher Order Component that will decorate other component:

	# test-children.rb
	# This is a stand-alone test case.
	# Run it in your console with: `rubytest-children.rb`
	# If you change the gem dependencies, run it with:
	# `rm gemfile* && ruby test-children.rb`

	unless File.exist?('Gemfile')
	File.write('Gemfile', <<-GEMFILE)
	source 'https://rubygems.org'
	# Rails master