Idris Yusupov sld

Polymorphic Associations reversed

It's pretty easy to do polymorphic associations in Rails: A Picture can belong to either a BlogPost or an Article. But what if you need the relationship the other way around? A Picture, a Text and a Video can belong to an Article, and that article can find all media by calling @article.media

This example shows how to create an ArticleElement join model that handles the polymorphic relationship. To add fields that are common to all polymorphic models, add fields to the join model.

	class PagesController < ApplicationController
	before_filter :login_required, :except => [ :show ]

	# GET /pages
	# GET /pages.xml
	def index
	@pages = Page.find(:all)

	respond_to do \|format\|
	format.html # index.html.erb

	import pyeliza

	class Eliza:
	aliases = 'eliza'
	description = 'Virtual therapist'
	_therapist = pyeliza.eliza()

	def execute(self, expression, context):
	'''
	>>> from mock import Mock

	set :rails_env, :production
	set :unicorn_binary, "/usr/bin/unicorn"
	set :unicorn_config, "#{current_path}/config/unicorn.rb"
	set :unicorn_pid, "#{current_path}/tmp/pids/unicorn.pid"

	namespace :deploy do
	task :start, :roles => :app, :except => { :no_release => true } do
	run "cd #{current_path} && #{try_sudo} #{unicorn_binary} -c #{unicorn_config} -E #{rails_env} -D"
	end
	task :stop, :roles => :app, :except => { :no_release => true } do

	# Mathieu Blondel, September 2010
	# License: BSD 3 clause

	import numpy as np
	from numpy import linalg
	import cvxopt
	import cvxopt.solvers

	def linear_kernel(x1, x2):
	return np.dot(x1, x2)

	# WAIT! Do consider that `wait` may not be needed. This article describes
	# that reasoning. Please read it and make informed decisions.
	# https://www.varvet.com/blog/why-wait_until-was-removed-from-capybara/

	# Have you ever had to sleep() in Capybara-WebKit to wait for AJAX and/or CSS animations?

	describe 'Modal' do

	should 'display login errors' do
	visit root_path

	require "try-catch"

	try {
	function()
	error('oops')
	end,

	catch {
	function(error)
	print('caught error: ' .. error)

	// Lefalet shortcuts for common tile providers - is it worth adding such 1.5kb to Leaflet core?

	L.TileLayer.Common = L.TileLayer.extend({
	initialize: function (options) {
	L.TileLayer.prototype.initialize.call(this, this.url, options);
	}
	});

	(function () {

	"""Information Retrieval metrics

	Useful Resources:
	http://www.cs.utexas.edu/~mooney/ir-course/slides/Evaluation.ppt
	http://www.nii.ac.jp/TechReports/05-014E.pdf
	http://www.stanford.edu/class/cs276/handouts/EvaluationNew-handout-6-per.pdf
	http://hal.archives-ouvertes.fr/docs/00/72/67/60/PDF/07-busa-fekete.pdf
	Learning to Rank for Information Retrieval (Tie-Yan Liu)
	"""
	import numpy as np

	A warning occurred (42 apples)
	An error occurred