@@ -416,8 +416,12 @@ Special values:
 
 * `:required => true` Will display a red '*' to show it's required
 * `:scope => :the_scope` Will scope parameters in the hash, scoping can be nested. See example
+* `:method => :method_name` Will use specified method as a parameter value
 
-The value of scoped parameters can be set with both scoped (`let(:order_item_item_id)`) and unscoped (`let(:item_id)`) methods. It always searches for the scoped method first and falls back to the unscoped method.
+Retrieving of parameter value goes through several steps:
+1. if `method` option is defined and test case responds to this method then this method is used;
+2. if test case responds to scoped method then this method is used;
+3. overwise unscoped method is used.
 
 ```ruby
 resource "Orders" do
@@ -428,10 +432,13 @@ resource "Orders" do
 post "/orders" do
 parameter :name, "Order Name", :required => true, :scope => :order
 parameter :item, "Order items", :scope => :order
-parameter :item_id, "Item id", :scope => [:order, :item]
+parameter :item_id, "Item id", :scope => [:order, :item], method: :custom_item_id
 
-let(:name) { "My Order" } # OR let(:order_name) { "My Order" }
-let(:item_id) { 1 } # OR let(:order_item_item_id) { 1 }
+let(:name) { "My Order" }
+# OR let(:order_name) { "My Order" }
+let(:item_id) { 1 }
+# OR let(:custom_item_id) { 1 }
+# OR let(:order_item_item_id) { 1 }
 
 example "Creating an order" do
 params.should eq({

@@ -1,6 +1,7 @@
 require 'rspec/core/formatters/base_formatter'
 require 'rack/utils'
 require 'rack/test/utils'
+require 'rspec_api_documentation/dsl/endpoint/params'
 
 module RspecApiDocumentation::DSL
 # DSL methods available inside the RSpec example.
@@ -63,11 +64,7 @@ def query_string
 end
 
 def params
-parameters = example.metadata.fetch(:parameters, {}).inject({}) do |hash, param|
-set_param(hash, param)
-end
-parameters.deep_merge!(extra_params)
-parameters
+Params.new(self, example, extra_params).call
 end
 
 def header(name, value)
@@ -99,14 +96,6 @@ def status
 rspec_api_documentation_client.status
 end
 
-def in_path?(param)
-path_params.include?(param)
-end
-
-def path_params
-example.metadata[:route].scan(/:(\w+)/).flatten
-end
-
 def path
 example.metadata[:route].gsub(/:(\w+)/) do |match|
 if extra_params.keys.include?($1)
@@ -146,26 +135,5 @@ def delete_extra_param(key)
 @extra_params.delete(key.to_sym) || @extra_params.delete(key.to_s)
 end
 
-def set_param(hash, param)
-key = param[:name]
-
-keys = [param[:scope], key].flatten.compact
-method_name = keys.join('_')
-
-return hash if in_path?(method_name)
-
-unless respond_to?(method_name)
-method_name = key
-return hash unless respond_to?(method_name)
-end
-
-hash.deep_merge(build_param_hash(keys, method_name))
-end
-
-def build_param_hash(keys, method_name)
-value = keys[1] ? build_param_hash(keys[1..-1], method_name) : send(method_name)
-{ keys[0].to_s => value }
-end
-
 end
 end

@@ -0,0 +1,30 @@
+require 'rspec_api_documentation/dsl/endpoint/set_param'
+
+module RspecApiDocumentation
+module DSL
+module Endpoint
+class Params
+attr_reader :example_group, :example
+
+def initialize(example_group, example, extra_params)
+@example_group = example_group
+@example = example
+@extra_params = extra_params
+end
+
+def call
+parameters = example.metadata.fetch(:parameters, {}).inject({}) do |hash, param|
+SetParam.new(self, hash, param).call
+end
+parameters.deep_merge!(extra_params)
+parameters
+end
+
+private
+
+attr_reader :extra_params
+
+end
+end
+end
+end

@@ -0,0 +1,62 @@
+module RspecApiDocumentation
+module DSL
+module Endpoint
+class SetParam
+def initialize(parent, hash, param)
+@parent = parent
+@hash = hash
+@param = param
+end
+
+def call
+return hash if path_params.include?(path_name)
+return hash unless method_name
+
+hash.deep_merge build_param_hash(key_scope || [key])
+end
+
+private
+
+attr_reader :parent, :hash, :param
+delegate :example_group, :example, to: :parent
+
+def key
+@key ||= param[:name]
+end
+
+def key_scope
+@key_scope ||= param[:scope] && Array(param[:scope]).dup.push(key)
+end
+
+def scoped_key
+@scoped_key ||= key_scope && key_scope.join('_')
+end
+
+def custom_method_name
+param[:method]
+end
+
+def path_name
+scoped_key || key
+end
+
+def path_params
+example.metadata[:route].scan(/:(\w+)/).flatten
+end
+
+def method_name
+@method_name ||= begin
+[custom_method_name, scoped_key, key].find do |name|
+name && example_group.respond_to?(name)
+end
+end
+end
+
+def build_param_hash(keys)
+value = keys[1] ? build_param_hash(keys[1..-1]) : example_group.send(method_name)
+{ keys[0].to_s => value }
+end
+end
+end
+end
+end

@@ -59,8 +59,8 @@
 post "/orders" do
 parameter :type, "The type of drink you want.", :required => true
 parameter :size, "The size of drink you want.", :required => true
-parameter :note, "Any additional notes about your order."
-parameter :name, :scope => :order
+parameter :note, "Any additional notes about your order.", method: :custom_note
+parameter :name, :scope => :order, method: :custom_order_name
 
 response_field :type, "The type of drink you ordered.", :scope => :order
 response_field :size, "The size of drink you ordered.", :scope => :order
@@ -71,6 +71,12 @@
 let(:type) { "coffee" }
 let(:size) { "medium" }
 
+let(:note) { "Made in Brazil" }
+let(:custom_note) { "Made in India" }
+
+let(:order_name) { "Nescoffee" }
+let(:custom_order_name) { "Jakobz" }
+
 describe "example metadata" do
 subject { |example| example.metadata }
 
@@ -79,8 +85,8 @@
 [
 { :name => "type", :description => "The type of drink you want.", :required => true },
 { :name => "size", :description => "The size of drink you want.", :required => true },
-{ :name => "note", :description => "Any additional notes about your order." },
-{ :name => "name", :description => "Order name", :scope => :order},
+{ :name => "note", :description => "Any additional notes about your order.", method: :custom_note },
+{ :name => "name", :description => "Order name", :scope => :order, method: :custom_order_name },
 ]
 )
 end
@@ -103,7 +109,12 @@
 
 describe "params" do
 it "should equal the assigned parameter values" do
-expect(params).to eq("type" => "coffee", "size" => "medium")
+expect(params).to eq({
+"type" => "coffee",
+"size" => "medium",
+"note" => "Made in India",
+"order" => { "name" => "Jakobz" }
+})
 end
 end
 end