Add offset pagination to trends in REST API (#17872)

1 files changed, 25 insertions, 1 deletions

diff --git a/app/controllers/api/v1/trends/tags_controller.rb b/app/controllers/api/v1/trends/tags_controller.rb
index 1334b72d2..d77857871 100644
--- a/app/controllers/api/v1/trends/tags_controller.rb
+++ b/app/controllers/api/v1/trends/tags_controller.rb
@@ -3,6 +3,10 @@
 class Api::V1::Trends::TagsController < Api::BaseController
   before_action :set_tags
 
+  after_action :insert_pagination_headers
+
+  DEFAULT_TAGS_LIMIT = 10
+
   def index
     render json: @tags, each_serializer: REST::TagSerializer
   end
@@ -12,10 +16,30 @@ class Api::V1::Trends::TagsController < Api::BaseController
   def set_tags
     @tags = begin
       if Setting.trends
-        Trends.tags.query.allowed.limit(limit_param(10))
+        Trends.tags.query.allowed.limit(limit_param(DEFAULT_TAGS_LIMIT))
       else
         []
       end
     end
   end
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def pagination_params(core_params)
+    params.slice(:limit).permit(:limit).merge(core_params)
+  end
+
+  def next_path
+    api_v1_trends_tags_url pagination_params(offset: offset_param + limit_param(DEFAULT_TAGS_LIMIT))
+  end
+
+  def prev_path
+    api_v1_trends_tags_url pagination_params(offset: offset_param - limit_param(DEFAULT_TAGS_LIMIT)) if offset_param > limit_param(DEFAULT_TAGS_LIMIT)
+  end
+
+  def offset_param
+    params[:offset].to_i
+  end
 end