rweald

class SimpleLinearRegression
  def initialize(xs, ys)
    @xs, @ys = xs, ys
    if @xs.length != @ys.length
      raise "Unbalanced data. xs need to be same length as ys"
    end
  end

  def y_intercept
    mean(@ys) - (slope * mean(@xs))

mike-burns

class User < Params.over(:first_name, :last_name)
  def info
    "I am a user: #{@first_name} #{@last_name}"
  end
end

class Admin < User.params(:awesomeness_level)
  def info
    "I am a level #{@awesomeness_level} admin: #{@first_name} #{@last_name}"
  end

dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

mgol

var ngAppElem = angular.element(document.querySelector('[ng-app]') || document);

window.$injector = ngAppElem.injector();
window.inject = $injector.invoke;
window.$rootScope = ngAppElem.scope();

// getService('auth') will create a variable `auth` assigned to the service `auth`.
var getService = serviceName =>
    inject([serviceName, s => window[serviceName] = s]);

smsohan

Because I think the hardest part of getting started with AngularJS is it's esoteric names, I'm suggesting the following replacements of the AngularJS terminology.

scope -> state

factory -> data/models

filter -> helper

directive {restrict: 'E'} -> custom_tag
directive {restrict: 'A'} -> custom_attribute

dhh

# config/routes.rb
resources :documents do
  scope module: 'documents' do
    resources :versions do
      post :restore, on: :member
    end

    resource :lock
  end
end

staltz

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.

---

jessegrosjean

var copyProperties = require('react/lib/copyProperties'),
    Dispatcher = require('flux').Dispatcher,
    util = require('util');

function AppDispatcher() {
    Dispatcher.call(this);
    this._queue = [];
}

util.inherits(AppDispatcher, Dispatcher);

wincent

2015-01-29 Unofficial Relay FAQ

Compilation of questions and answers about Relay from React.js Conf.

Disclaimer: I work on Relay at Facebook. Relay is a complex system on which we're iterating aggressively. I'll do my best here to provide accurate, useful answers, but the details are subject to change. I may also be wrong. Feedback and additional questions are welcome.

What is Relay?

Relay is a new framework from Facebook that provides data-fetching functionality for React applications. It was announced at React.js Conf (January 2015).

gaearon

// ------------
// counterStore.js
// ------------

import {
  INCREMENT_COUNTER,
  DECREMENT_COUNTER
} from '../constants/ActionTypes';

const initialState = { counter: 0 };