add URI template support

hactor.gemspec

@@ -18,4 +18,5 @@ Gem::Specification.new do |gem|
   gem.require_paths = ["lib"]
   gem.add_development_dependency 'rspec'
   gem.add_dependency 'faraday'
+  gem.add_dependency 'addressable'
 end

lib/hactor/hal/link.rb

@@ -1,15 +1,30 @@
 require 'ostruct'
+require 'addressable/template'
 
 module Hactor
   module HAL
     class Link < OpenStruct
-      attr_reader :rel, :parent_resource
+      attr_reader :rel, :parent_resource, :template_class
 
       def initialize(obj, options)
+        @href = obj[:href]
         @rel = options.fetch(:rel)
         @parent_resource = options.fetch(:context)
+        @template_class = options[:template_class] || Addressable::Template
         super(obj)
       end
+
+      def href(variables={})
+        if templated?
+          template_class.new(@href).expand(variables).to_s
+        else
+          @href
+        end
+      end
+
+      def templated?
+        !!templated
+      end
     end
   end
 end

lib/hactor/http/client.rb

@@ -17,7 +17,7 @@ def follow(link, options = {})
         actor = options[:actor] || Hactor::NullActor.new
         variables = options[:expand_with]
 
-        href = variables ? link.expand_with(variables) : link.href
+        href = variables ? link.href(variables) : link.href
         url = context_url.merge(href)
 
         get(url: url, actor: actor)

spec/hactor/hal/link_spec.rb

@@ -0,0 +1,33 @@
+require 'spec_helper'
+require 'hactor/hal/link'
+
+describe Hactor::HAL::Link do
+  context "templated link" do
+    let(:template_class) { mock }
+    let(:template) { mock }
+    let(:href) { stub }
+    let(:link) do
+      Hactor::HAL::Link.new({
+        href: href,
+        templated: true
+      },{
+        rel: stub,
+        context: stub,
+        template_class: template_class
+      })
+    end
+
+    describe "#href" do
+      it "expands using the variables passed in" do
+        sentinel, variables = stub, stub
+
+        template_class.should_receive(:new).with(href).
+          and_return(template)
+        template.should_receive(:expand).with(variables).
+          and_return(stub(to_s: sentinel))
+
+        link.href(variables).should == sentinel
+      end
+    end
+  end
+end

spec/hactor/http/client_spec.rb

@@ -57,7 +57,7 @@
         it "should apply the variables to the template and follow resulting URI" do
           variables = stub
 
-          link.should_receive(:expand_with).with(variables).and_return(uri)
+          link.should_receive(:href).with(variables).and_return(uri)
           context_url.should_receive(:merge).with(uri).and_return(resolved_uri)
 
           client.follow(link, context_url: context_url, actor: actor, expand_with: variables)