Added support for _curries.

Author: dblock

CHANGELOG.md

@@ -7,6 +7,7 @@
   * [#58](https://github.com/codegram/hyperclient/issues/58): Automatically follow redirects (by [@dblock](https://github.com/dblock)).
   * [#63](https://github.com/codegram/hyperclient/pull/63): You can omit the navigational elements, `api.links.products` is now equivalent to `api.products` (by @dblock).
   * Implemented Rubocop, Ruby-style linter (by @dblock).
+  * [#64](https://github.com/codegram/hyperclient/issues/64): Added support for curies (by [@dblock](https://github.com/dblock)).
 
 * bug fixes
   * Nothing.

lib/hyperclient/curie.rb

@@ -0,0 +1,49 @@
+require 'hyperclient/resource'
+
+module Hyperclient
+  # Internal: Curies are named tokens that you can define in the document and use
+  # to express curie relation URIs in a friendlier, more compact fashion.
+  #
+  class Curie
+    # Public: Initializes a new Curie.
+    #
+    # curie          - The String with the URI of the curie.
+    # entry_point   - The EntryPoint object to inject the cofnigutation.
+    def initialize(curie_hash, entry_point)
+      @curie_hash = curie_hash
+      @entry_point = entry_point
+    end
+
+    # Public: Indicates if the curie is an URITemplate or a regular URI.
+    #
+    # Returns true if it is templated.
+    # Returns false if it not templated.
+    def templated?
+      !!@curie_hash['templated']
+    end
+
+    # Public: Returns the name property of the Curie
+    def name
+      @curie_hash['name']
+    end
+
+    # Public: Returns the href property of the Curie
+    def href
+      @curie_hash['href']
+    end
+
+    def inspect
+      "#<#{self.class.name} #{@curie_hash}>"
+    end
+
+    # Public: Expands the Curie when is templated with the given variables.
+    #
+    # rel - The rel to expand.
+    #
+    # Returns a new expanded url.
+    def expand(rel)
+      return rel unless rel && templated?
+      href.gsub('{rel}', rel) if href
+    end
+  end
+end

lib/hyperclient/link_collection.rb

@@ -1,5 +1,6 @@
 require 'hyperclient/collection'
 require 'hyperclient/link'
+require 'hyperclient/curie'
 
 module Hyperclient
   # Public: A wrapper class to easily acces the links in a  Resource.
@@ -12,13 +13,19 @@ module Hyperclient
   class LinkCollection < Collection
     # Public: Initializes a LinkCollection.
     #
-    # collection  - The Hash with the links.
+    # collection - The Hash with the links.
+    # curies - Link curies.
     # entry_point - The EntryPoint object to inject the configuration.
-    def initialize(collection, entry_point)
+    def initialize(collection, curies, entry_point)
       fail "Invalid response for LinkCollection. The response was: #{collection.inspect}" if collection && !collection.respond_to?(:collect)
 
+      @curies = (curies || {}).reduce({}) do |hash, curie_hash|
+        curie = build_curie(curie_hash, entry_point)
+        hash.update(curie.name => curie)
+      end
+
       @collection = (collection || {}).reduce({}) do |hash, (name, link)|
-        hash.update(name => build_link(name, link, entry_point))
+        hash.update(name => build_link(name, link, @curies, entry_point))
       end
     end
 
@@ -27,16 +34,33 @@ def initialize(collection, entry_point)
     # Internal: Creates links from the response hash.
     #
     # link_or_links - A Hash or an Array of hashes with the links to build.
-    # entry_point   - The EntryPoint object to inject the configuration.
+    # entry_point - The EntryPoint object to inject the configuration.
+    # curies - Optional curies for templated links.
     #
     # Returns a Link or an array of Links when given an Array.
-    def build_link(name, link_or_links, entry_point)
+    def build_link(name, link_or_links, curies, entry_point)
       return unless link_or_links
-      return Link.new(name, link_or_links, entry_point) unless link_or_links.respond_to?(:to_ary)
-
-      link_or_links.map do |link|
-        build_link(name, link, entry_point)
+      if link_or_links.respond_to?(:to_ary)
+        link_or_links.map do |link|
+          build_link(name, link, curies, entry_point)
+        end
+      elsif (curie_parts = /(?<ns>[^:]+):(?<short_name>.+)/.match(name))
+        curie = curies[curie_parts[:ns]]
+        link_or_links['href'] = curie.expand(link_or_links['href']) if curie
+        Link.new(name, link_or_links, entry_point)
+      else
+        Link.new(name, link_or_links, entry_point)
       end
     end
+
+    # Internal: Creates a curie from the response hash.
+    #
+    # curie_hash - A Hash with the curie.
+    # entry_point - The EntryPoint object to inject the configuration.
+    #
+    # Returns a Link or an array of Links when given an Array.
+    def build_curie(curie_hash, entry_point)
+      Curie.new(curie_hash, entry_point)
+    end
   end
 end

lib/hyperclient/resource.rb

@@ -33,7 +33,7 @@ class Resource
     # entry_point    - The EntryPoint object to inject the configutation.
     def initialize(representation, entry_point, response = nil)
       representation = representation ? representation.dup : {}
-      @_links       = LinkCollection.new(representation['_links'], entry_point)
+      @_links       = LinkCollection.new(representation['_links'], representation['_curies'], entry_point)
       @_embedded    = ResourceCollection.new(representation['_embedded'], entry_point)
       @_attributes  = Attributes.new(representation)
       @_entry_point = entry_point

test/fixtures/element.json

@@ -1,4 +1,11 @@
 {
+    "_curies" : [
+        {
+          "name": "image",
+          "href": "/images/{rel}",
+          "templated": true
+        }
+    ],
     "_links": {
         "self": {
             "href": "/productions/1"
@@ -15,7 +22,11 @@
                 "href": "/gizmos/2"
             }
         ],
-        "null_link": null
+        "null_link": null,
+        "image:thumbnail": {
+          "href": "thumbnails/{version}.jpg",
+          "templated": true
+        }
     },
     "title": "Real World ASP.NET MVC3",
     "description": "In this advanced, somewhat-opinionated production you'll get your very own startup off the ground using ASP.NET MVC 3...",

test/hyperclient/collection_test.rb

@@ -32,7 +32,7 @@ module Hyperclient
         name
       end
 
-      names.must_equal %w(_links title description permitted _hidden_attribute _embedded)
+      names.must_equal %w(_curies _links title description permitted _hidden_attribute _embedded)
     end
 
     describe '#to_hash' do

test/hyperclient/curie_test.rb

@@ -0,0 +1,34 @@
+require_relative '../test_helper'
+require 'hyperclient/curie'
+require 'hyperclient/entry_point'
+
+module Hyperclient
+  describe Curie do
+    let(:entry_point) do
+      EntryPoint.new('http://api.example.org/')
+    end
+
+    describe 'templated?' do
+      it 'returns true if the curie is templated' do
+        curie = Curie.new({ 'name' => 'image', 'templated' => true }, entry_point)
+
+        curie.templated?.must_equal true
+      end
+
+      it 'returns false if the curie is not templated' do
+        curie = Curie.new({ 'name' => 'image' }, entry_point)
+
+        curie.templated?.must_equal false
+      end
+    end
+
+    let(:curie) do
+      Curie.new({ 'name' => 'image', 'href' => '/images/{?rel}', 'templated' => true }, entry_point)
+    end
+    describe '_name' do
+      it 'returns curie name' do
+        curie.name.must_equal 'image'
+      end
+    end
+  end
+end

test/hyperclient/link_collection_test.rb

@@ -10,7 +10,7 @@ module Hyperclient
     end
 
     let(:links) do
-      LinkCollection.new(representation['_links'], entry_point)
+      LinkCollection.new(representation['_links'], representation['_curies'], entry_point)
     end
 
     it 'is a collection' do
@@ -30,6 +30,27 @@ module Hyperclient
       links['gizmos'].must_be_kind_of Array
     end
 
+    describe 'plain link' do
+      let(:plain_link) { links.self }
+      it 'must be correct' do
+        plain_link._url.must_equal '/productions/1'
+      end
+    end
+
+    describe 'templated link' do
+      let(:templated_link) { links.filter }
+      it 'must expand' do
+        templated_link._expand(filter: 'gizmos')._url.must_equal '/productions/1?categories=gizmos'
+      end
+    end
+
+    describe 'curied link' do
+      let(:curied_link) { links['image:thumbnail'] }
+      it 'must expand' do
+        curied_link._expand(version: 'small')._url.must_equal '/images/thumbnails/small.jpg'
+      end
+    end
+
     describe 'array of links' do
       let(:gizmos) { links.gizmos }
 

test/hyperclient/resource_test.rb

@@ -7,7 +7,7 @@ module Hyperclient
 
     describe 'initialize' do
       it 'initializes its links' do
-        LinkCollection.expects(:new).with({ 'self' => { 'href' => '/orders/523' } }, entry_point)
+        LinkCollection.expects(:new).with({ 'self' => { 'href' => '/orders/523' } }, nil, entry_point)
 
         Resource.new({ '_links' => { 'self' => { 'href' => '/orders/523' } } }, entry_point)
       end