add 'Link' header for API response

Nihad Abbasov
1 parent ff7073ac
Showing 2 changed files with 24 additions and 2 deletions Show diff stats
lib/api/helpers.rb
spec/requests/api/issues_spec.rb
@@ -51,8 +51,12 @@ module API
       end
     end
-    def paginate(object)
-      object.page(params[:page]).per(params[:per_page].to_i)
+    def paginate(relation)
+      per_page  = params[:per_page].to_i
+      paginated = relation.page(params[:page]).per(per_page)
+      add_pagination_headers(paginated, per_page)
+
+      paginated
     end
     def authenticate!
@@ -129,6 +133,18 @@ module API
     private
+    def add_pagination_headers(paginated, per_page)
+      request_url = request.url.split('?').first
+
+      links = []
+      links << %(<#{request_url}?page=#{paginated.current_page - 1}&per_page=#{per_page}>; rel="prev") unless paginated.first_page?
+      links << %(<#{request_url}?page=#{paginated.current_page + 1}&per_page=#{per_page}>; rel="next") unless paginated.last_page?
+      links << %(<#{request_url}?page=1&per_page=#{per_page}>; rel="first")
+      links << %(<#{request_url}?page=#{paginated.total_pages}&per_page=#{per_page}>; rel="last")
+
+      header 'Link', links.join(', ')
+    end
+
     def abilities
       @abilities ||= begin
                        abilities = Six.new
@@ -25,6 +25,12 @@ describe API::API do
         json_response.should be_an Array
         json_response.first['title'].should == issue.title
       end
+
+      it "should add pagination headers" do
+        get api("/issues?per_page=3", user)
+        response.headers['Link'].should ==
+          '<http://www.example.com/api/v3/issues?page=1&per_page=3>; rel="first", <http://www.example.com/api/v3/issues?page=1&per_page=3>; rel="last"'
+      end
     end
   end
	@@ -51,8 +51,12 @@ module API		@@ -51,8 +51,12 @@ module API
51	end	51	end
52	end	52	end
53		53
54	- def paginate(object)
55	- object.page(params[:page]).per(params[:per_page].to_i)	54	+ def paginate(relation)
		55	+ per_page = params[:per_page].to_i
		56	+ paginated = relation.page(params[:page]).per(per_page)
		57	+ add_pagination_headers(paginated, per_page)
		58	+
		59	+ paginated
56	end	60	end
57		61
58	def authenticate!	62	def authenticate!
	@@ -129,6 +133,18 @@ module API		@@ -129,6 +133,18 @@ module API
129		133
130	private	134	private
131		135
		136	+ def add_pagination_headers(paginated, per_page)
		137	+ request_url = request.url.split('?').first
		138	+
		139	+ links = []
		140	+ links << %(<#{request_url}?page=#{paginated.current_page - 1}&per_page=#{per_page}>; rel="prev") unless paginated.first_page?
		141	+ links << %(<#{request_url}?page=#{paginated.current_page + 1}&per_page=#{per_page}>; rel="next") unless paginated.last_page?
		142	+ links << %(<#{request_url}?page=1&per_page=#{per_page}>; rel="first")
		143	+ links << %(<#{request_url}?page=#{paginated.total_pages}&per_page=#{per_page}>; rel="last")
		144	+
		145	+ header 'Link', links.join(', ')
		146	+ end
		147	+
132	def abilities	148	def abilities
133	@abilities \|\|= begin	149	@abilities \|\|= begin
134	abilities = Six.new	150	abilities = Six.new
	@@ -25,6 +25,12 @@ describe API::API do		@@ -25,6 +25,12 @@ describe API::API do
25	json_response.should be_an Array	25	json_response.should be_an Array
26	json_response.first['title'].should == issue.title	26	json_response.first['title'].should == issue.title
27	end	27	end
		28	+
		29	+ it "should add pagination headers" do
		30	+ get api("/issues?per_page=3", user)
		31	+ response.headers['Link'].should ==
		32	+ '<http://www.example.com/api/v3/issues?page=1&per_page=3>; rel="first", <http://www.example.com/api/v3/issues?page=1&per_page=3>; rel="last"'
		33	+ end
28	end	34	end
29	end	35	end
30		36