Add pagination headers to already paginated API resourcesadd-pagination-headers-to-api

2 files changed, 22 insertions, 20 deletions

diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index a4df810e755..312ef90915f 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -97,11 +97,9 @@ module API
     end
 
     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
+      relation.page(params[:page]).per(params[:per_page].to_i).tap do |data|
+        add_pagination_headers(data)
+      end
     end
 
     def authenticate!
@@ -327,16 +325,26 @@ module API
 
     private
 
-    def add_pagination_headers(paginated, per_page)
+    def add_pagination_headers(paginated_data)
+      header 'X-Total',       paginated_data.total_count.to_s
+      header 'X-Total-Pages', paginated_data.total_pages.to_s
+      header 'X-Per-Page',    paginated_data.limit_value.to_s
+      header 'X-Page',        paginated_data.current_page.to_s
+      header 'X-Next-Page',   paginated_data.next_page.to_s
+      header 'X-Prev-Page',   paginated_data.prev_page.to_s
+      header 'Link',          pagination_links(paginated_data)
+    end
+
+    def pagination_links(paginated_data)
       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")
+      links << %(<#{request_url}?page=#{paginated_data.current_page - 1}&per_page=#{paginated_data.limit_value}>; rel="prev") unless paginated_data.first_page?
+      links << %(<#{request_url}?page=#{paginated_data.current_page + 1}&per_page=#{paginated_data.limit_value}>; rel="next") unless paginated_data.last_page?
+      links << %(<#{request_url}?page=1&per_page=#{paginated_data.limit_value}>; rel="first")
+      links << %(<#{request_url}?page=#{paginated_data.total_pages}&per_page=#{paginated_data.limit_value}>; rel="last")
 
-      header 'Link', links.join(', ')
+      links.join(', ')
     end
 
     def abilities
diff --git a/lib/api/notes.rb b/lib/api/notes.rb
index 174473f5371..ebd9e97148c 100644
--- a/lib/api/notes.rb
+++ b/lib/api/notes.rb
@@ -22,17 +22,11 @@ module API
           @noteable = user_project.send(:"#{noteables_str}").find(params[:"#{noteable_id_str}"])
 
           # We exclude notes that are cross-references and that cannot be viewed
-          # by the current user. By doing this exclusion at this level and not
-          # at the DB query level (which we cannot in that case), the current
-          # page can have less elements than :per_page even if
-          # there's more than one page.
+          # by the current user.
           notes =
-            # paginate() only works with a relation. This could lead to a
-            # mismatch between the pagination headers info and the actual notes
-            # array returned, but this is really a edge-case.
-            paginate(@noteable.notes).
+            @noteable.notes.
             reject { |n| n.cross_reference_not_visible_for?(current_user) }
-          present notes, with: Entities::Note
+          present paginate(Kaminari.paginate_array(notes)), with: Entities::Note
         end
 
         # Get a single +noteable+ note