ParseResource

ParseResource makes it easy to interact with Parse.com's REST API. It adheres to the ActiveRecord pattern. ParseResource is fully ActiveModel compliant, meaning you can use validations and Rails forms.

Ruby/Rails developers should feel right at home.

If you're used to Post.create(:title => "Hello, world", :author => "Octocat"), then this is for you.

Features

ActiveRecord-like API, almost no learning curve
Validations
Rails forms and scaffolds just work

Use cases

Build a custom admin dashboard for your Parse.com data
Use the same database for your web and native apps
Pre-collect data for use in iOS and Android apps

Installation

Include in your Gemfile:

gem "parse_resource", "~> 1.7.2"

Or just gem install:

gem install parse_resource

Create an account at Parse.com. Then create an application and copy the app_id and master_key into a file called parse_resource.yml. If you're using a Rails app, place this file in the config folder.

development:
  app_id: 1234567890
  master_key: abcdefgh

test:
  app_id: 1234567890
  master_key: abcdefgh

production:
  app_id: 1234567890
  master_key: abcdefgh

You can create separate Parse databases if you want. If not, include the same info for each environment.

In a non-Rails app, include this somewhere (preferable in an initializer):

ParseResource::Base.load!("your_app_id", "your_master_key")

Usage

Create a model:

class Post < ParseResource::Base
  fields :title, :author, :body

  validates_presence_of :title
end

If you are using version 1.5.11 or earlier, subclass to just ParseResource--or just update to the most recent version.

Creating, updating, and deleting:

p = Post.new

# validations
p.valid? #=> false 
p.errors #=> #<ActiveModel::Errors:0xab71998 ... @messages={:title=>["can't be blank"]}> 
p.title = "Introducing ParseResource" #=> "Introducing ParseResource" 
p.valid? #=> true 

# setting more attributes, then saving
p.author = "Alan deLevie" 
p.body = "Ipso Lorem"
p.save #=> true

# checking the id generated by Parse's servers
p.id #=> "QARfXUILgY" 
p.updated_at #=> nil 
p.created_at #=> "2011-09-19T01:32:04.973Z" # does anybody want this to be a DateTime object? Let me know.

# updating
p.title = "[Update] Introducing ParseResource"
p.save #=> true
p.updated_at #=> "2011-09-19T01:32:37.930Z" # more magic from Parse's servers

# destroying an object
p.destroy #=> true 
p.title #=> nil

Finding:

posts = Post.where(:author => "Arrington")
# the query is lazy loaded
# nothing gets sent to the Parse server until you run #all, #count, or any Array method on the query 
# (e.g. #first, #each, or #map)

posts.each do |post|
  "#{post.title}, by #{post.author}"
end

posts.map {|p| p.title} #=> ["Unpaid blogger", "Uncrunched"]

id = "DjiH4Qffke"
p = Post.find(id) #simple find by id

# ActiveRecord style find commands
Post.find_by_title("Uncrunched") #=> A Post object
Post.find_all_by_author("Arrington") #=> An Array of Posts

# you can chain method calls, just like in ActiveRecord
Post.where(:param1 => "foo").where(:param2 => "bar").all

# destroy all objects
Post.destroy_all

# limit the query
posts = Post.limit(5).where(:foo => "bar")
posts.length #=> 5

# get a count
Post.where(:bar => "foo").count #=> 1337

Users

Note: Because users are special in the Parse API, you must name your class User if you want to subclass ParseUser.

# app/models/user.rb
class User < ParseUser
  # no validations included, but feel free to add your own
  validates_presence_of :username

  # you can add fields, like any other kind of Object...
  fields :name, :bio

  # but note that email is a special field in the Parse API.
  fields :email
end

# create a user
user = User.new(:username => "adelevie")
user.password = "asecretpassword"
user.save #=> true
# after saving, the password is automatically hashed by Parse's server
# user.password will return the unhashed password when the original object is in memory
# from a new session, User.where(:username => "adelevie").first.password will return nil

# check if a user is logged in
User.authenticate("adelevie", "foooo") #=> false
User.authenticate("adelevie", "asecretpassword") #=> #<User...>


# A simple controller to authenticate users
class SessionsController < ApplicationController
  def new
  end

  def create
    user = User.authenticate(params[:username], params[:password])
    if user
      session[:user_id] = user.id
      redirect_to root_url, :notice => "logged in !"
    else
      flash.now.alert = "Invalid username or password"
      render "new"
    end
  end

  def destroy
    session[:user_id] = nil
    redirect_to root_url, :notice => "Logged out!"
  end

end

If you want to use parse_resource to back a simple authentication system for a Rails app, follow this tutorial, and make some simple modifications.

DEPRECATED Associations

class Post < ParseResource::Base
  # As with ActiveRecord, associations names can differ from class names...
  belongs_to :author, :class_name => 'User'
  fields :title, :body
end

class User < ParseUser
  # ... but on the other end, use :inverse_of to complete the link.
  has_many :posts, :inverse_of => :author
  field :name
end

author = Author.create(:name => "RL Stine")
post1 = Post.create(:title => "Goosebumps 1")
post2 = Post.create(:title => "Goosebumps 2")

# assign from parent class
author.posts << post1
author.posts << post2 

# or assign from child class
post3 = Post.create(:title => "Goosebumps 3")
post3.author = author
post3.save #=> true

# relational queries
posts = Post.include_object(:author).all
posts.each do |post|
    puts post.author.name
    # because you used Post#include_object, calling post.title won't execute a new query
    # this is similar to ActiveRecord's eager loading
end

File Upload

  @post = Post.first()
  result = Post.upload(uploaded_file.tempfile, uploaded_file.original_filename, content_type: uploaded_file.content_type)
  @post.thumbnail = {"name" => result["name"], "__type" => "File"}

Documentation

Here

To-do

User authentication
Better documentation
~~Associations~~
Callbacks
Push notifications
Better type-casting
HTTP request error handling

User authentication is my top priority feature. Several people have specifically requested it, and Parse just began exposing User objects in the REST API.

Let me know of any other features you want.

Contributing to ParseResource

Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
Fork the project
Start a feature/bugfix branch
Commit and push until you are happy with your contribution
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Create parse_resource.yml in the root of the gem folder. Using the same format as parse_resource.yml in the instructions (except only creating a test environment, add your own API keys.
Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.