MotionResource

This is a library for using JSON APIs in RubyMotion apps. It is based on RemoteModel, however it is an almost complete rewrite. Also, it is inspired by ActiveResource.

This gem needs RubyMotion version 2.3 or higher.

Installation

Add MotionResource to your Gemfile, like this:

gem "motion-resource"

Example

Consider this example for a fictional blog API.

class User < MotionResource::Base
  attr_accessor :id

  has_many :posts

  self.collection_url = "users"
  self.member_url = "users/:id"
end

class Post < MotionResource::Base
  attr_accessor :id
  attribute :user_id, :title, :text

  belongs_to :user

  self.collection_url = "users/:user_id/posts"
  self.member_url = "users/:user_id/posts/:id"
end

Only attributes declared with attribute are transmitted on save. I.e. attributes declared with attr_accessor are considered read-only with respect to the JSON API.

Now, we can access a user's posts like that:

User.find(1) do |user|
  user.posts do |posts|
    puts posts.inspect
  end
end

Note that the blocks are called asynchronously.

URL encoding

A different url encoding implementation can be substituted by setting MotionResource::Base.url_encoder. For instance to include the fixed parameter 'foo' on every request:

class CustomEncoder < MotionResource::UrlEncoder
  def build_query_string(url, params = {})
    params[:foo] = 42
    super(url, params)
  end
end
MotionResource::Base.url_encoder = CustomEncoder.new

Error Handling

Pass a second block parameter to capture error information:

User.find_all do |users, response|
  if response.ok?
    puts users.inspect
  else
    App.alert response.error_message
  end
end

response will be an instance of BubbleWrap::HTTP::Response

Reachability

It's important to check the reachability status of a host before making a request, or you may get intermitent connectivity errors. For an example of how to do so, see when_reachable in TinyMon.

Setup

You can configure every model separately; however you will most likely want to configure things like the root_url the same for every model:

MotionResource::Base.root_url = "http://localhost:3000/"

Don't forget the trailing '/' here!

Forking

Feel free to fork and submit pull requests!