From 1d3ecd3fbaf15450890c1ece7955846fba82a58d Mon Sep 17 00:00:00 2001
From: Matt Jankowski <matt@jankowski.online>
Date: Wed, 17 Apr 2024 05:22:45 -0400
Subject: [PATCH] Add `API::Pagination` concern (#28826)

---
 app/controllers/api/base_controller.rb     | 28 +----------------
 app/controllers/concerns/api/pagination.rb | 36 ++++++++++++++++++++++
 2 files changed, 37 insertions(+), 27 deletions(-)
 create mode 100644 app/controllers/concerns/api/pagination.rb

diff --git a/app/controllers/api/base_controller.rb b/app/controllers/api/base_controller.rb
index f87d596ce3..c1a5e43f88 100644
--- a/app/controllers/api/base_controller.rb
+++ b/app/controllers/api/base_controller.rb
@@ -9,6 +9,7 @@ class Api::BaseController < ApplicationController
   include Api::CachingConcern
   include Api::ContentSecurityPolicy
   include Api::ErrorHandling
+  include Api::Pagination
 
   skip_before_action :require_functional!, unless: :limited_federation_mode?
 
@@ -29,21 +30,6 @@ class Api::BaseController < ApplicationController
 
   protected
 
-  def pagination_max_id
-    pagination_collection.last.id
-  end
-
-  def pagination_since_id
-    pagination_collection.first.id
-  end
-
-  def set_pagination_headers(next_path = nil, prev_path = nil)
-    links = []
-    links << [next_path, [%w(rel next)]] if next_path
-    links << [prev_path, [%w(rel prev)]] if prev_path
-    response.headers['Link'] = LinkHeader.new(links) unless links.empty?
-  end
-
   def limit_param(default_limit)
     return default_limit unless params[:limit]
 
@@ -72,10 +58,6 @@ class Api::BaseController < ApplicationController
     render json: { error: 'Your login is currently disabled' }, status: 403 if current_user&.account&.unavailable?
   end
 
-  def require_valid_pagination_options!
-    render json: { error: 'Pagination values for `offset` and `limit` must be positive' }, status: 400 if pagination_options_invalid?
-  end
-
   def require_user!
     if !current_user
       render json: { error: 'This method requires an authenticated user' }, status: 422
@@ -104,14 +86,6 @@ class Api::BaseController < ApplicationController
 
   private
 
-  def insert_pagination_headers
-    set_pagination_headers(next_path, prev_path)
-  end
-
-  def pagination_options_invalid?
-    params.slice(:limit, :offset).values.map(&:to_i).any?(&:negative?)
-  end
-
   def respond_with_error(code)
     render json: { error: Rack::Utils::HTTP_STATUS_CODES[code] }, status: code
   end
diff --git a/app/controllers/concerns/api/pagination.rb b/app/controllers/concerns/api/pagination.rb
new file mode 100644
index 0000000000..d84a1d99f7
--- /dev/null
+++ b/app/controllers/concerns/api/pagination.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Api::Pagination
+  extend ActiveSupport::Concern
+
+  protected
+
+  def pagination_max_id
+    pagination_collection.last.id
+  end
+
+  def pagination_since_id
+    pagination_collection.first.id
+  end
+
+  def set_pagination_headers(next_path = nil, prev_path = nil)
+    links = []
+    links << [next_path, [%w(rel next)]] if next_path
+    links << [prev_path, [%w(rel prev)]] if prev_path
+    response.headers['Link'] = LinkHeader.new(links) unless links.empty?
+  end
+
+  def require_valid_pagination_options!
+    render json: { error: 'Pagination values for `offset` and `limit` must be positive' }, status: 400 if pagination_options_invalid?
+  end
+
+  private
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def pagination_options_invalid?
+    params.slice(:limit, :offset).values.map(&:to_i).any?(&:negative?)
+  end
+end