Add support form custom primary keys

lib/her/model.rb

@@ -53,6 +53,9 @@ module Model
       # Assign the default API
       uses_api Her::API.default_api
 
+      # Define the default primary key
+      primary_key :id
+
       # Configure ActiveModel callbacks
       extend ActiveModel::Callbacks
       define_model_callbacks :create, :update, :save, :find, :destroy

lib/her/model/associations.rb

@@ -94,7 +94,7 @@ def has_many(name, attrs={})
 
             if @attributes[name].blank? || method_attrs.any?
               path = begin
-                self.class.build_request_path(@attributes.merge(method_attrs))
+                request_path(method_attrs)
               rescue Her::Errors::PathError
                 return nil
               end
@@ -147,7 +147,7 @@ def has_one(name, attrs={})
 
             if @attributes[name].blank? || method_attrs.any?
               path = begin
-                self.class.build_request_path(@attributes.merge(method_attrs))
+                request_path(method_attrs)
               rescue Her::Errors::PathError
                 return nil
               end
@@ -195,7 +195,7 @@ def belongs_to(name, attrs={})
 
             if @attributes[name].blank? || method_attrs.any?
               path = begin
-                klass.build_request_path(@attributes.merge(method_attrs.merge(:id => @attributes[attrs[:foreign_key].to_sym])))
+                klass.build_request_path(@attributes.merge(method_attrs.merge(klass.primary_key => @attributes[attrs[:foreign_key].to_sym])))
               rescue Her::Errors::PathError
                 return nil
               end

lib/her/model/attributes.rb

@@ -103,10 +103,10 @@ def get_attribute(attribute_name)
       end
       alias :get_data :get_attribute
 
-      # Override the method to prevent from returning the object ID (in ruby-1.8.7)
+      # Override the method to prevent from returning the object ID
       # @private
       def id
-        attributes[:id] || super
+        attributes[self.class.primary_key] || super
       end
 
       # Return `true` if the other object is also a Her::Model and has matching data

lib/her/model/orm.rb

@@ -6,7 +6,7 @@ module ORM
 
       # Return `true` if a resource was not saved yet
       def new?
-        attributes[:id].nil?
+        attributes[self.class.primary_key].nil?
       end
 
       # Return `true` if a resource is not `#new?`
@@ -36,12 +36,12 @@ def save
         params = to_params
         resource = self
 
-        if attributes[:id]
-          callback = :update
-          method = :put
-        else
+        if new?
           callback = :create
           method = :post
+        else
+          callback = :update
+          method = :put
         end
 
         run_callbacks callback do
@@ -93,7 +93,7 @@ def find(*ids)
           params = ids.last.is_a?(Hash) ? ids.pop : {}
           results = ids.flatten.compact.uniq.map do |id|
             resource = nil
-            request(params.merge(:_method => :get, :_path => "#{build_request_path(params.merge(:id => id))}")) do |parsed_data, response|
+            request(params.merge(:_method => :get, :_path => "#{build_request_path(params.merge(primary_key => id))}")) do |parsed_data, response|
               if response.success?
                 resource = new(parse(parsed_data[:data]).merge :_metadata => parsed_data[:metadata], :_errors => parsed_data[:errors])
                 resource.run_callbacks :find
@@ -151,7 +151,7 @@ def create(params={})
         #   @user = User.save_existing(1, { :fullname => "Tobias Fünke" })
         #   # Called via PUT "/users/1"
         def save_existing(id, params)
-          resource = new(params.merge(:id => id))
+          resource = new(params.merge(primary_key => id))
           resource.save
           resource
         end
@@ -162,7 +162,7 @@ def save_existing(id, params)
         #   User.destroy_existing(1)
         #   # Called via DELETE "/users/1"
         def destroy_existing(id, params={})
-          request(params.merge(:_method => :delete, :_path => "#{build_request_path(params.merge(:id => id))}")) do |parsed_data, response|
+          request(params.merge(:_method => :delete, :_path => "#{build_request_path(params.merge(primary_key => id))}")) do |parsed_data, response|
             new(parse(parsed_data[:data]).merge(:_destroyed => true))
           end
         end

lib/her/model/paths.rb

@@ -11,12 +11,29 @@ module Paths
       #   end
       #
       #   User.find(1) # Fetched via GET /utilisateurs/1
-      def request_path
-        self.class.build_request_path(attributes.dup)
+      #
+      # @param [Hash] params An optional set of additional parameters for
+      #   path construction. These will not override attributes of the resource.
+      def request_path(params = {})
+        self.class.build_request_path(params.merge(attributes.dup))
       end
 
       module ClassMethods
 
+        # Define the primary key field that will be used to find and save records
+        #
+        # @example
+        #  class User
+        #    include Her::Model
+        #    primary_key 'UserId'
+        #  end
+        #
+        # @param [Symbol] field
+        def primary_key(field = nil)
+          return @her_primary_key if field.nil?
+          @her_primary_key = field.to_sym
+        end
+
         # Defines a custom collection path for the resource
         #
         # @example
@@ -41,6 +58,22 @@ def collection_path(path=nil)
         #    include Her::Model
         #    resource_path "/users/:id"
         #  end
+        #
+        # Note that, if used in combination with resource_path, you may specify
+        # either the real primary key or the string ':id'. For example:
+        #
+        # @example
+        #  class User
+        #    include Her::Model
+        #    primary_key 'user_id'
+        #
+        #    # This works because we'll have a user_id attribute
+        #    resource_path '/users/:user_id'
+        #
+        #    # This works because we replace :id with :user_id
+        #    resource_path '/users/:id'
+        #  end
+        #
         def resource_path(path=nil)
           @_her_resource_path ||= begin
             superclass.resource_path.dup if superclass.respond_to?(:resource_path)
@@ -62,7 +95,15 @@ def resource_path(path=nil)
         def build_request_path(path=nil, parameters={})
           unless path.is_a?(String)
             parameters = path || {}
-            path = parameters.include?(:id) && !parameters[:id].nil? ? resource_path : collection_path
+            path =
+              if parameters.include?(primary_key) && parameters[primary_key]
+                resource_path.dup
+              else
+                collection_path.dup
+              end
+
+            # Replace :id with our actual primary key
+            path.gsub!(/(\A|\/):id(\Z|\/)/, "\\1:#{primary_key}\\2")
           end
 
           path.gsub(/:([\w_]+)/) do

spec/model/orm_spec.rb

@@ -11,7 +11,8 @@
         builder.adapter :test do |stub|
           stub.get("/users/1") { |env| [200, {}, { :id => 1, :name => "Tobias Fünke" }.to_json] }
           stub.get("/users") { |env| [200, {}, [{ :id => 1, :name => "Tobias Fünke" }, { :id => 2, :name => "Lindsay Fünke" }].to_json] }
-          stub.get("/admin_users") { |env| [200, {}, [{ :id => 1, :name => "Tobias Fünke" }, { :id => 2, :name => "Lindsay Fünke" }].to_json] }
+          stub.get("/admin_users") { |env| [200, {}, [{ :admin_id => 1, :name => "Tobias Fünke" }, { :admin_id => 2, :name => "Lindsay Fünke" }].to_json] }
+          stub.get("/admin_users/1") { |env| [200, {}, { :admin_id => 1, :name => "Tobias Fünke" }.to_json] }
         end
       end
 
@@ -21,13 +22,18 @@
 
       spawn_model "Foo::AdminUser" do
         uses_api api
+        primary_key :admin_id
       end
     end
 
     it "maps a single resource to a Ruby object" do
       @user = Foo::User.find(1)
       @user.id.should == 1
       @user.name.should == "Tobias Fünke"
+
+      @admin = Foo::AdminUser.find(1)
+      @admin.id.should == 1
+      @admin.name.should == "Tobias Fünke"
     end
 
     it "maps a collection of resources to an array of Ruby objects" do
@@ -48,6 +54,14 @@
       @existing_user = Foo::User.find(1)
       @existing_user.new?.should be_false
     end
+
+    it 'handles new resource with custom primary key' do
+      @new_user = Foo::AdminUser.new(:fullname => 'Lindsay Fünke', :id => -1)
+      @new_user.should be_new
+
+      @existing_user = Foo::AdminUser.find(1)
+      @existing_user.should_not be_new
+    end
   end
 
   context "mapping data, metadata and error data to Ruby objects" do

spec/model/paths_spec.rb

@@ -137,6 +137,32 @@
         end
       end
     end
+
+    context 'custom primary key' do
+      before do
+        spawn_model 'User' do
+          primary_key 'UserId'
+          resource_path 'users/:UserId'
+        end
+
+        spawn_model 'Customer' do
+          primary_key :customer_id
+          resource_path 'customers/:id'
+        end
+      end
+
+      describe '#build_request_path' do
+        it 'uses the correct primary key attribute' do
+          User.build_request_path(:UserId => 'foo').should == 'users/foo'
+          User.build_request_path(:id => 'foo').should == 'users'
+        end
+
+        it 'replaces :id with the appropriate primary key' do
+          Customer.build_request_path(:customer_id => 'joe').should == 'customers/joe'
+          Customer.build_request_path(:id => 'joe').should == 'customers'
+        end
+      end
+    end
   end
 
   context "making subdomain HTTP requests" do