Class: OandaAPI::ResourceCollection

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/oanda_api/resource_collection.rb

Overview

A collection of a specific resource. Returned by API requests that return collections. See the Oanda Development Guide for documentation about resource attributes expected for specific requests.

Examples:

Getting candle information

client  = OandaAPI::Client::TokenClient.new :practice, token
candles = client.candles( instrument: "EUR_USD",
                         granularity: "M1",
                               count: 1,
                       candle_format: "midpoint" ).get

candles              # => OandaAPI::ResourceCollection
candles.granularity  # => "M1"
candles.instrument   # => "EUR_USD"
candles.first        # => OandaAPI::Resource::Candle

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(attributes, resource_descriptor) ⇒ ResourceCollection 



29
30
31
32
33
34
35
36
 
# File 'lib/oanda_api/resource_collection.rb', line 29

def initialize(attributes, resource_descriptor)
  attributes = {} if attributes.nil? || attributes.respond_to?(:empty) && attributes.empty?
  fail ArgumentError, "Expecting a Hash" unless attributes.respond_to? :each_pair
  @attributes = Utils.rubyize_keys attributes
  @collection = @attributes.delete(resource_descriptor.collection_name) || []
  @collection.map! { |resource| resource_descriptor.resource_klass.new resource }
  @location   = attributes.location if attributes.respond_to? :location
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args) ⇒ Object

Responds to collection-scoped accessor methods that are specific to the type of resource collection. For example, a +Candle+ collection includes the collection-scoped methods +granularity+ and +instrument+.



52
53
54
55
56
57
58
59
60
61
62
 
# File 'lib/oanda_api/resource_collection.rb', line 52

def method_missing(sym, *args)
  case
  when @attributes.keys.include?(sym) 
    @attributes[sym]
  when
    @collection.respond_to?(sym)
      @collection.send sym
  else
    super
  end
end

Instance Attribute Details

#location ⇒ String (readonly) 



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
 
# File 'lib/oanda_api/resource_collection.rb', line 20

class ResourceCollection
  include Enumerable

  attr_reader :location

  # @param [Hash] attributes collection of resource attributes
  #
  # @param [OandaAPI::Client::ResourceDescriptor] resource_descriptor metadata
  #   about the resource collection and its elements.
  def initialize(attributes, resource_descriptor)
    attributes = {} if attributes.nil? || attributes.respond_to?(:empty) && attributes.empty?
    fail ArgumentError, "Expecting a Hash" unless attributes.respond_to? :each_pair
    @attributes = Utils.rubyize_keys attributes
    @collection = @attributes.delete(resource_descriptor.collection_name) || []
    @collection.map! { |resource| resource_descriptor.resource_klass.new resource }
    @location   = attributes.location if attributes.respond_to? :location
  end

  # @yield [OandaAPI::ResourceBase]
  # @return [Enumerator]
  def each
    if block_given?
      @collection.each { |el| yield el }
    else
      @collection.each
    end
  end

  # @private
  # Responds to collection-scoped accessor methods that are specific to the
  # type of resource collection. For example, a +Candle+ collection includes
  # the collection-scoped methods +granularity+ and +instrument+.
  def method_missing(sym, *args)
    case
    when @attributes.keys.include?(sym) 
      @attributes[sym]
    when
      @collection.respond_to?(sym)
        @collection.send sym
    else
      super
    end
  end

  # Returns +true+ for concrete, delegated and dynamic methods.
  # @return [Boolean]
  def respond_to?(sym)
    case
    when @attributes.keys.include?(sym)
      true
    when @collection.respond_to?(sym)
      true
    else
      super
    end
  end
end

Instance Method Details

#each {|OandaAPI::ResourceBase| ... } ⇒ Enumerator

Yields:



40
41
42
43
44
45
46
 
# File 'lib/oanda_api/resource_collection.rb', line 40

def each
  if block_given?
    @collection.each { |el| yield el }
  else
    @collection.each
  end
end

#respond_to?(sym) ⇒ Boolean

Returns +true+ for concrete, delegated and dynamic methods.



66
67
68
69
70
71
72
73
74
75
 
# File 'lib/oanda_api/resource_collection.rb', line 66

def respond_to?(sym)
  case
  when @attributes.keys.include?(sym)
    true
  when @collection.respond_to?(sym)
    true
  else
    super
  end
end