add pagination to API

doc/api/README.md

@@ -23,6 +23,13 @@ GET http://example.com/api/v2/projects?private_token=QVy1PB7sTxfy4pqfZM1U
 
 The API uses JSON to serialize data. You don't need to specify `.json` at the end of API URL.
 
+#### Pagination
+
+When listing resources you can pass the following parameters:
+
++ `page` (default: `1`) - page number
++ `per_page` (default: `20`, max: `100`) - how many items to list per page
+
 ## Contents
 
 + [Users](https://github.com/gitlabhq/gitlabhq/blob/master/doc/api/users.md)

lib/api/helpers.rb

@@ -14,6 +14,10 @@ module Gitlab
       @project
     end
 
+    def paginate(object)
+      object.page(params[:page]).per(params[:per_page].to_i)
+    end
+
     def authenticate!
       error!({'message' => '401 Unauthorized'}, 401) unless current_user
     end

lib/api/issues.rb

@@ -9,7 +9,7 @@ module Gitlab
       # Example Request:
       #   GET /issues
       get do
-        present current_user.issues, with: Entities::Issue
+        present paginate(current_user.issues), with: Entities::Issue
       end
     end
 
@@ -21,7 +21,7 @@ module Gitlab
       # Example Request:
       #   GET /projects/:id/issues
       get ":id/issues" do
-        present user_project.issues, with: Entities::Issue
+        present paginate(user_project.issues), with: Entities::Issue
       end
 
       # Get a single project issue

lib/api/milestones.rb

@@ -11,7 +11,7 @@ module Gitlab
       # Example Request:
       #   GET /projects/:id/milestones
       get ":id/milestones" do
-        present user_project.milestones, with: Entities::Milestone
+        present paginate(user_project.milestones), with: Entities::Milestone
       end
 
       # Get a single project milestone

lib/api/projects.rb

@@ -9,7 +9,7 @@ module Gitlab
       # Example Request:
       #   GET /projects
       get do
-        @projects = current_user.projects
+        @projects = paginate current_user.projects
         present @projects, with: Entities::Project
       end
 

lib/api/users.rb

@@ -9,7 +9,7 @@ module Gitlab
       # Example Request:
       #  GET /users
       get do
-        @users = User.all
+        @users = paginate User
         present @users, with: Entities::User
       end