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	51	end
52	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	60	end
57	61
58	62	def authenticate!
...	...	@@ -129,6 +133,18 @@ module API
129	133
130	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	148	def abilities
133	149	@abilities \|\|= begin
134	150	abilities = Six.new
...	...
...	...	@@ -25,6 +25,12 @@ describe API::API do
25	25	json_response.should be_an Array
26	26	json_response.first['title'].should == issue.title
27	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	34	end
29	35	end
30	36
...	...