Module: FormObject::ClassMethods

Defined in:
lib/form_object.rb

Instance Method Summary collapse

Instance Method Details

#form_object_for(resource_name, options = {}) ⇒ Object

Set up the Form Object class to be a form object for a given model.

Example:

class NewWorkflow

include FormObject
form_object_for :workflow, :fields => [:name], :class => MyOtherClass
...

This creates a :workflow attr method and delegates methods to it for use with form_for.



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# File 'lib/form_object.rb', line 22

def form_object_for(resource_name, options={})
  # create an attribute for the underlying resource name, (eg :workflow) and make an alias method "resource"
  # for the attr reader
  attr resource_name
  alias_method :resource, resource_name

  # create a class attribute with the model name of the underlying model name so that polymorphic_url will
  # see the form object as if it were an instance of the underlying model object.
  class_attribute :model_name
  klass = options[:class] || resource_name.to_s
  klass = klass.camelize.constantize unless klass.is_a?(Class)
  self.model_name = klass.model_name

  # delegate the following methods to the underlying model object, also helps polymorphic_url do the right thing
  # for `form_for @form_object`
  methods_to_delegate = [:id, :persisted?, :to_param]
  if options[:fields]
    options[:fields].each do |field|
      methods_to_delegate << "#{field}".to_sym
      methods_to_delegate << "#{field}=".to_sym
    end
  end
  delegate *methods_to_delegate, :to => resource_name
  include DelegateEverything if options[:delegate_everything]

  # create a default initializer which will set the resource when a single parameter is passed in.
  define_method :initialize do |object=nil|
    instance_variable_set("@#{resource_name}", object)
  end
end