Additional filters cannot take the name into account

[Saverio Trioni]

The comment at https://github.com/cypriss/mutations/blob/master/lib/mutations/model_filter.rb#L5

# default is the attribute name.to_s.camelize.constantize.

indicates that the class of a model (if not given) is generated using the attribute name. But there is no way for the filter to know the name of the attribute, because it's never passed to the initializer:

# https://github.com/cypriss/mutations/blob/master/lib/mutations/hash_filter.rb#L8
@current_inputs[name.to_sym] = type_class.new(options, &block)

the name is never passed to the constructor, with two nasty consequences:

1. There is no way to set the model class from the name of the attribute.
2. The options in the filter initializer are always empty, so the class constraint always resolves to Object, making it totally useless.

update

the ModelFilter is treated very differently than the rest of filters, so this actually applies only to custom additional filters, not to the model filter itself.

[Saverio Trioni]

Ok the model name is managed specifically in the HashFilter with a specialized method model. So there is no way to generate additional filters that take into account the name.

This class resolves the issue:

module Mutations
  # a filter that is able to take its own name to operate
  class AdditionalNameAwareFilter < ::Mutations::InputFilter
    def initialize(name, opts = {})
      super(opts)
      @name = name
    end

    def self.inherited(base)
      type_name = base.name[/^Mutations::([a-zA-Z]*)Filter$/, 1].underscore

      Mutations::HashFilter.class_eval do
        define_method(type_name) do |name, options = {}, &block|
          @current_inputs[name.to_sym] = base.new(name, options, &block)
        end
      end

      Mutations::ArrayFilter.class_eval do
        define_method(type_name) do |name, options = {}, &block|
          @element_filter = base.new(name, options, &block)
        end
      end
    end
  end
end

[Elian Krosse]

I'm not a big fan of the the AdditionalNameAwareFilter idea. But I don't like the special treatment the ModelFilter has either. Its a bit to much magic just to avoid having to add a parameter

[Saverio Trioni]

So why can't we just always pass the field name as additional option to the constructor?