Class: ReactiveResource::Association::BelongsToAssociation

Inherits:
Object
  • Object
show all
Defined in:
lib/reactive_resource/association/belongs_to_association.rb

Overview

Represents and resolves a belongs_to association.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(klass, attribute, options) ⇒ BelongsToAssociation

Create a new belongs_to association.



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 89

def initialize(klass, attribute, options)
  @klass = klass
  @attribute = attribute
  @options = options

  add_helper_methods(klass, attribute)
end

Instance Attribute Details

#attribute ⇒ Object (readonly)

The attribute name this association represents



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 10

def attribute
  @attribute
end

#klass ⇒ Object (readonly)

The class this association is attached to



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 7

def klass
  @klass
end

#options ⇒ Object (readonly)

additional options passed in when the association was created



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 13

def options
  @options
end

Instance Method Details

#add_helper_methods(klass, attribute) ⇒ Object

Adds methods for belongs_to associations, to make dealing with these objects a bit more straightforward. If the attribute name is lawyer, it will add:

lawyer

returns the actual lawyer object (after doing a web request)

lawyer_id

returns the lawyer id

lawyer_id=

sets the lawyer id



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 51

def add_helper_methods(klass, attribute)
  association = self
  
  klass.class_eval do 
    # address.lawyer_id
    define_method("#{attribute}_id") do
      prefix_options["#{attribute}_id".intern]
      super()
    end
    
    # address.lawyer_id = 3
    define_method("#{attribute}_id=") do |value|
      prefix_options["#{attribute}_id".intern] = value
      super(value)
    end

    # address.lawyer
    define_method(attribute) do
      # if the parent has its own belongs_to associations, we need
      # to add those to the 'find' call. So, let's grab all of
      # these associations, turn them into a hash of :attr_name =>
      # attr_id, and fire off the find.
      
      unless instance_variable_get("@#{attribute}")
        object = association.resolve_relationship(self)
        instance_variable_set("@#{attribute}", object)
      end
      instance_variable_get("@#{attribute}")
    end
  end
  
  # Recurse through the parent object.
  associated_class.belongs_to_associations.each do |parent_attribute|
    parent_attribute.add_helper_methods(klass, parent_attribute.attribute)
  end
end

#associated_attributes ⇒ Object

A flattened list of attributes from the entire association belongs_to hierarchy, including this association’s attribute.



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 28

def associated_attributes
  attributes = [attribute]
  if associated_class
    attributes += associated_class.belongs_to_associations.map(&:attribute)
  end
  attributes.uniq
end

#associated_class ⇒ Object

Returns the class name of the target of the association. Based off of attribute unless class_name was passed in the options hash.



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 18

def associated_class
  if options[:class_name]
    options[:class_name].constantize
  else
    klass.relative_const_get(attribute.to_s.camelize)
  end
end

#resolve_relationship(object) ⇒ Object

Called when this assocation is referenced. Finds and returns the target of this association.



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# File 'lib/reactive_resource/association/belongs_to_association.rb', line 38

def resolve_relationship(object)
  parent_params = object.prefix_options.dup
  parent_params.delete("#{attribute}_id".intern)
  associated_class.find(object.send("#{attribute}_id"), :params => parent_params)
end