Move common query limit method of changesets and notes to mixin

app/controllers/api/changesets_controller.rb

@@ -2,6 +2,8 @@
 
 module Api
   class ChangesetsController < ApiController
+    include QueryMethods
+
     before_action :check_api_writable, :only => [:create, :update, :upload, :subscribe, :unsubscribe]
     before_action :setup_user_auth, :only => [:show]
     before_action :authorize, :only => [:create, :update, :upload, :close, :subscribe, :unsubscribe]
@@ -43,7 +45,7 @@ module Api
                    end
 
       # limit the result
-      changesets = changesets.limit(result_limit)
+      changesets = query_limit(changesets)
 
       # preload users, tags and comments, and render result
       @changesets = changesets.preload(:user, :changeset_tags, :comments)
@@ -403,19 +405,5 @@ module Api
         changesets.where(:id => ids)
       end
     end
-
-    ##
-    # Get the maximum number of results to return
-    def result_limit
-      if params[:limit]
-        if params[:limit].to_i.positive? && params[:limit].to_i <= Settings.max_changeset_query_limit
-          params[:limit].to_i
-        else
-          raise OSM::APIBadUserInput, "Changeset limit must be between 1 and #{Settings.max_changeset_query_limit}"
-        end
-      else
-        Settings.default_changeset_query_limit
-      end
-    end
   end
 end

app/controllers/api/notes_controller.rb

@@ -1,5 +1,7 @@
 module Api
   class NotesController < ApiController
+    include QueryMethods
+
     before_action :check_api_writable, :only => [:create, :comment, :close, :reopen, :destroy]
     before_action :setup_user_auth, :only => [:create, :show]
     before_action :authorize, :only => [:close, :reopen, :destroy, :comment]
@@ -36,7 +38,9 @@ module Api
       @max_lat = bbox.max_lat
 
       # Find the notes we want to return
-      @notes = notes.bbox(bbox).order("updated_at DESC").limit(result_limit).preload(:comments)
+      notes = notes.bbox(bbox).order("updated_at DESC")
+      notes = query_limit(notes)
+      @notes = notes.preload(:comments)
 
       # Render the result
       respond_to do |format|
@@ -234,8 +238,9 @@ module Api
 
       # Find the comments we want to return
       @comments = NoteComment.where(:note => notes)
-                             .order(:created_at => :desc).limit(result_limit)
+                             .order(:created_at => :desc)
-                             .preload(:author, :note => { :comments => :author })
+      @comments = query_limit(@comments)
+      @comments = @comments.preload(:author, :note => { :comments => :author })
 
       # Render the result
       respond_to do |format|
@@ -311,7 +316,8 @@ module Api
                end
 
       # Find the notes we want to return
-      @notes = @notes.distinct.limit(result_limit).preload(:comments)
+      @notes = query_limit(@notes.distinct)
+      @notes = @notes.preload(:comments)
 
       # Render the result
       respond_to do |format|
@@ -328,20 +334,6 @@ module Api
     # utility functions below.
     #------------------------------------------------------------
 
-    ##
-    # Get the maximum number of results to return
-    def result_limit
-      if params[:limit]
-        if params[:limit].to_i.positive? && params[:limit].to_i <= Settings.max_note_query_limit
-          params[:limit].to_i
-        else
-          raise OSM::APIBadUserInput, "Note limit must be between 1 and #{Settings.max_note_query_limit}"
-        end
-      else
-        Settings.default_note_query_limit
-      end
-    end
-
     ##
     # Generate a condition to choose which notes we want based
     # on their status and the user's request parameters

app/controllers/concerns/query_methods.rb

@@ -0,0 +1,27 @@
+module QueryMethods
+  extend ActiveSupport::Concern
+
+  private
+
+  ##
+  # Limit the result according to request parameters and settings
+  def query_limit(items)
+    items.limit(query_limit_value)
+  end
+
+  ##
+  # Get query limit value from request parameters and settings
+  def query_limit_value
+    max_limit = Settings["max_#{controller_name.singularize}_query_limit"]
+    default_limit = Settings["default_#{controller_name.singularize}_query_limit"]
+    if params[:limit]
+      if params[:limit].to_i.positive? && params[:limit].to_i <= max_limit
+        params[:limit].to_i
+      else
+        raise OSM::APIBadUserInput, "#{controller_name.classify} limit must be between 1 and #{max_limit}"
+      end
+    else
+      default_limit
+    end
+  end
+end