Class: ActiveResource::Collection

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/active_resource/collection.rb

Overview

:nodoc:

Constant Summary collapse

SELF_DEFINE_METHODS = 
[:to_a, :collect!, :map!, :all?]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(elements = []) ⇒ Collection

ActiveResource::Collection is a wrapper to handle parsing index responses that do not directly map to Rails conventions.

You can define a custom class that inherits from ActiveResource::Collection in order to to set the elements instance.

GET /posts.json delivers following response body:

{
  posts: [
    {
      title: "ActiveResource now has associations",
      body: "Lorem Ipsum"
    },
    {...}
  ],
  next_page: "/posts.json?page=2"
}

A Post class can be setup to handle it with:

class Post < ActiveResource::Base
  self.site = "http://example.com"
  self.collection_parser = PostCollection
end

And the collection parser:

class PostCollection < ActiveResource::Collection
  attr_accessor :next_page
  def initialize(parsed = {})
    @elements = parsed['posts']
    @next_page = parsed['next_page']
  end
end

The result from a find method that returns multiple entries will now be a PostParser instance. ActiveResource::Collection includes Enumerable and instances can be iterated over just like an array.

@posts = Post.find(:all) # => PostCollection:xxx
@posts.next_page         # => "/posts.json?page=2"
@posts.map(&:id)         # =>[1, 3, 5 ...]

The initialize method will receive the ActiveResource::Formats parsed result and should set @elements.



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# File 'lib/active_resource/collection.rb', line 59

def initialize(elements = [])
  @elements = elements
end

Instance Attribute Details

#elements ⇒ Object

The array of actual elements returned by index actions



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# File 'lib/active_resource/collection.rb', line 13

def elements
  @elements
end

#original_params ⇒ Object

The array of actual elements returned by index actions



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# File 'lib/active_resource/collection.rb', line 13

def original_params
  @original_params
end

#resource_class ⇒ Object

The array of actual elements returned by index actions



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# File 'lib/active_resource/collection.rb', line 13

def resource_class
  @resource_class
end

Instance Method Details

#collect! ⇒ Object Also known as: map! 



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# File 'lib/active_resource/collection.rb', line 67

def collect!
  return elements unless block_given?
  set = []
  each { |o| set << yield(o) }
  @elements = set
  self
end

#first_or_create(attributes = {}) ⇒ Object 



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# File 'lib/active_resource/collection.rb', line 76

def first_or_create(attributes = {})
  first || resource_class.create(original_params.update(attributes))
rescue NoMethodError
  raise "Cannot create resource from resource type: #{resource_class.inspect}"
end

#first_or_initialize(attributes = {}) ⇒ Object 



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# File 'lib/active_resource/collection.rb', line 82

def first_or_initialize(attributes = {})
  first || resource_class.new(original_params.update(attributes))
rescue NoMethodError
  raise "Cannot build resource from resource type: #{resource_class.inspect}"
end

#to_a ⇒ Object 



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# File 'lib/active_resource/collection.rb', line 63

def to_a
  elements
end

#where(clauses = {}) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/active_resource/collection.rb', line 88

def where(clauses = {})
  raise ArgumentError, "expected a clauses Hash, got #{clauses.inspect}" unless clauses.is_a? Hash
  new_clauses = original_params.merge(clauses)
  resource_class.where(new_clauses)
end