Merge pull request #232 from jackcasey/resource-level-links-update

Resource level links update

Author: richmolj

lib/graphiti/resource.rb

@@ -148,5 +148,15 @@ def transaction
       end
       response
     end
+
+    def links?
+      self.class.links.any?
+    end
+
+    def links(model)
+      self.class.links.each_with_object({}) do |(name, blk), memo|
+        memo[name] = instance_exec(model, &blk)
+      end
+    end
   end
 end

lib/graphiti/resource/configuration.rb

@@ -199,7 +199,8 @@ def config
               attributes: {},
               extra_attributes: {},
               sideloads: {},
-              callbacks: {}
+              callbacks: {},
+              links: {}
             }
         end
 
@@ -238,6 +239,10 @@ def pagination
         def default_filters
           config[:default_filters]
         end
+
+        def links
+          config[:links]
+        end
       end
 
       def get_attr!(name, flag, options = {})

lib/graphiti/resource/dsl.rb

@@ -147,6 +147,10 @@ def on_extra_attribute(name, &blk)
           end
         end
 
+        def link(name, &blk)
+          config[:links][name.to_sym] = blk
+        end
+
         def all_attributes
           attributes.merge(extra_attributes)
         end

lib/graphiti/serializer.rb

@@ -25,6 +25,7 @@ def self.inherited(klass)
     def as_jsonapi(*)
       super.tap do |hash|
         strip_relationships!(hash) if strip_relationships?
+        add_links!(hash)
       end
     end
 
@@ -49,6 +50,12 @@ def respond_to_missing?(method_name, include_private = true)
 
     private
 
+    def add_links!(hash)
+      return unless @resource.respond_to?(:links?)
+
+      hash[:links] = @resource.links(@object) if @resource.links?
+    end
+
     def strip_relationships!(hash)
       hash[:relationships]&.select! do |name, payload|
         payload.key?(:data)

spec/serialization_spec.rb

@@ -860,7 +860,7 @@ def admin?(object)
     end
   end
 
-  describe "links" do
+  describe "relationship links" do
     let!(:employee) { PORO::Employee.create }
 
     def positions
@@ -1377,4 +1377,39 @@ def classification
       end
     end
   end
+
+  describe "resource-level links" do
+    let!(:employee) { PORO::Employee.create(id: 123) }
+    context "by default" do
+      specify "are not emitted" do
+        render
+
+        expect(json["data"][0]).not_to have_key("links")
+      end
+    end
+
+    context "when specified" do
+      before do
+        resource.link :test_link do |model| "#{endpoint[:url]}/#{model.id}" end
+      end
+
+      it "links correctly" do
+        render
+        expect(json["data"][0]["links"]["test_link"])
+          .to eq("/poro/employees/123")
+      end
+    end
+
+    context "nil links" do
+      before do
+        resource.link :test_link do |model| nil end
+      end
+
+      specify "are still included" do
+        render
+        expect(json["data"][0]["links"]).to have_key("test_link")
+        expect(json["data"][0]["links"]["test_link"]).to eq(nil)
+      end
+    end
+  end
 end