module DSL

module Helpers

extend ActiveSupport::Concern

include Grape::DSL::Configuration

module ClassMethods

# Add helper methods that will be accessible from any

# endpoint within this namespace (and child namespaces).

#

# When called without a block, all known helpers within this scope

# are included.

#

# @param [Array] new_modules optional array of modules to include

# @param [Block] block optional block of methods to include

#

# @example Define some helpers.

#

# class ExampleAPI < Grape::API

# helpers do

# def current_user

# User.find_by_id(params[:token])

# end

# end

# end

#

# @example Include many modules

#

# class ExampleAPI < Grape::API

# helpers Authentication, Mailer, OtherModule

# end

#

def helpers(*new_modules, &block)

include_new_modules(new_modules)

include_block(block)

include_all_in_scope if !block && new_modules.empty?

end

protected

def include_new_modules(modules)

return if modules.empty?

modules.each { |mod| make_inclusion(mod) }

end

def include_block(block)

return unless block

Module.new.tap do |mod|

make_inclusion(mod) { mod.class_eval(&block) }

end

end

def make_inclusion(mod, &block)

define_boolean_in_mod(mod)

inject_api_helpers_to_mod(mod, &block)

namespace_stackable(:helpers, mod)

end

def include_all_in_scope

Module.new.tap do |mod|

namespace_stackable(:helpers).each { |mod_to_include| mod.include mod_to_include }

change!

end

end

def define_boolean_in_mod(mod)

return if defined? mod::Boolean

mod.const_set(:Boolean, Grape::API::Boolean)

end

def inject_api_helpers_to_mod(mod, &block)

mod.extend(BaseHelper) unless mod.is_a?(BaseHelper)

yield if block

mod.api_changed(self)

end

end

# This module extends user defined helpers

# to provide some API-specific functionality.

module BaseHelper

attr_accessor :api

def params(name, &block)

@named_params ||= {}

@named_params[name] = block

end

def api_changed(new_api)

@api = new_api

process_named_params

end

protected

def process_named_params

return unless instance_variable_defined?(:@named_params) && @named_params && @named_params.any?

api.namespace_stackable(:named_params, @named_params)

end

end

end

end