Angel skozz

#Heroku, Ruby on Rails and PhantomJS

In this post, I’m going to show you how to modify an existing Ruby on Rails app running on Heroku’s Cedar stack to use PhantomJS for screen scraping. If you’ve never heard of PhantomJS, it’s a command-line WebKit-based browser (that supports JavaScript, cookies, etc.).

Let’s get started. This is a high-level overview of the required steps:

Modify your app to use multiple Heroku buildpacks.
Extend your app to use both the Ruby as well as the PhantomJS buildpacks.
Confirm that everything worked.

Business Models

Advertising

Models	Examples
Display ads	Yahoo!
Search ads	Google

From Meteor's documentation:

In Meteor, your server code runs in a single thread per request, not in the asynchronous callback style typical of Node. We find the linear execution model a better fit for the typical server code in a Meteor application.

This guide serves as a mini-tour of tools, trix and patterns that can be used to run async code in Meteor.

Basic async

Sometimes we need to run async code in Meteor.methods. For this we create a Future to block until the async code has finished. This pattern can be seen all over Meteor's own codebase:

	##################################################################
	# /etc/elasticsearch/elasticsearch.yml
	#
	# Base configuration for a write heavy cluster
	#

	# Cluster / Node Basics
	cluster.name: logng

	# Node can have abritrary attributes we can use for routing

	require 'test_helper'

	# testing rake task app:awesome_report
	# defined in file lib/tasks/app/awesome_report.rake

	describe 'App::AwesomeReportTaskTest' do
	it 'generates the awesomeness report' do
	subject.invoke
	assert File.exists?('awesomeness_report.csv')
	end

	class Person < ActiveRecord::Base

	# This manual SQL query...
	scope :allowed_to_eat_cheese, joins(
	<<-SQL
	INNER JOIN cities ON people.city_id = cities.id
	INNER JOIN states ON cities.state_id = states.id
	SQL
	).where('states.allows_cheese_consumption' = 'Yeppers')

	<object data="http://www.website.com/responsive/img/logo.svg" type="image/svg+xml" class="logo">
	<!--[if lte IE 8 ]-->
	<img src="http://www.website.com/responsive/img/logo.gif" alt="Image Title">
	<!--![endif]-->
	</object>

	<!-- Edit .svg file and erase width and height properties so it can automatically scale with viewport -->
	<!--
	CSS:
	img, object {

	# Example usage:
	require 'active_record/nonpersisted_attribute_methods'
	class Node < ActiveRecord::Base
	include ActiveRecord::NonPersistedAttributeMethods

	define_nonpersisted_attribute_methods [:bar]

	# Example of using with ancestry and getting :parent to show up in changes hash.
	has_ancestry
	define_nonpersisted_attribute_methods [:parent]

	# This file should be placed on the directory of ~/blog/config

	upstream unicorn {
	server unix:/tmp/unicorn.todo.socket fail_timeout=0;
	}

	server {
	listen 80 default;
	#server_name example.com;
	root /home/username/blog/public;

	access_key_id: xxx
	secret_access_key: yyy