+ end
+
+ # Add the commenter to the subscribers if necessary
+ changeset.subscribers << current_user unless changeset.subscribers.exists?(current_user.id)
+
+ # Return a copy of the updated changeset
+ render :xml => changeset.to_xml.to_s
+ end
+
+ ##
+ # Adds a subscriber to the changeset
+ def subscribe
+ # Check the arguments are sane
+ raise OSM::APIBadUserInput, "No id was given" unless params[:id]
+
+ # Extract the arguments
+ id = params[:id].to_i
+
+ # Find the changeset and check it is valid
+ changeset = Changeset.find(id)
+ raise OSM::APIChangesetNotYetClosedError, changeset if changeset.is_open?
+ raise OSM::APIChangesetAlreadySubscribedError, changeset if changeset.subscribers.exists?(current_user.id)
+
+ # Add the subscriber
+ changeset.subscribers << current_user
+
+ # Return a copy of the updated changeset
+ render :xml => changeset.to_xml.to_s
+ end
+
+ ##
+ # Removes a subscriber from the changeset
+ def unsubscribe
+ # Check the arguments are sane
+ raise OSM::APIBadUserInput, "No id was given" unless params[:id]
+
+ # Extract the arguments
+ id = params[:id].to_i
+
+ # Find the changeset and check it is valid
+ changeset = Changeset.find(id)
+ raise OSM::APIChangesetNotYetClosedError, changeset if changeset.is_open?
+ raise OSM::APIChangesetNotSubscribedError, changeset unless changeset.subscribers.exists?(current_user.id)
+
+ # Remove the subscriber
+ changeset.subscribers.delete(current_user)
+
+ # Return a copy of the updated changeset
+ render :xml => changeset.to_xml.to_s
+ end
+
+ ##
+ # Sets visible flag on comment to false
+ def hide_comment
+ # Check the arguments are sane
+ raise OSM::APIBadUserInput, "No id was given" unless params[:id]
+
+ # Extract the arguments
+ id = params[:id].to_i
+
+ # Find the changeset
+ comment = ChangesetComment.find(id)
+
+ # Hide the comment
+ comment.update(:visible => false)
+
+ # Return a copy of the updated changeset
+ render :xml => comment.changeset.to_xml.to_s
+ end
+
+ ##
+ # Sets visible flag on comment to true
+ def unhide_comment
+ # Check the arguments are sane
+ raise OSM::APIBadUserInput, "No id was given" unless params[:id]
+
+ # Extract the arguments
+ id = params[:id].to_i
+
+ # Find the changeset
+ comment = ChangesetComment.find(id)
+
+ # Unhide the comment
+ comment.update(:visible => true)
+
+ # Return a copy of the updated changeset
+ render :xml => comment.changeset.to_xml.to_s
+ end
+
+ ##
+ # Get a feed of recent changeset comments
+ def comments_feed
+ if params[:id]
+ # Extract the arguments
+ id = params[:id].to_i