From f4d70ceedcbbe66bb5ee7177c86f6faf883f8b12 Mon Sep 17 00:00:00 2001
From: Fomafix <fomafix@googlemail.com>
Date: Thu, 15 Dec 2016 15:01:49 +0100
Subject: [PATCH] mediawiki.special.watchlist: Optimize JavaScript code

* Create progress bar not before submit.
* Reenable the disabled reset button after response.
  Currently a reload of the watch list after reset may lead to a disabled
  reset button.
* Reduce indenting by make an early return.
* Add some line breaks for better readability.
* Add some comments.

Follows-up to 9ea1142fad935999ac64e2920321520c1bbbfb61

Change-Id: Ibfafa140172bae55be01383ef7a9899104d46938
---
 .../mediawiki.special.watchlist.js            | 71 +++++++++++--------
 1 file changed, 40 insertions(+), 31 deletions(-)

diff --git a/resources/src/mediawiki.special/mediawiki.special.watchlist.js b/resources/src/mediawiki.special/mediawiki.special.watchlist.js
index bfe2c1c3ae..223770f43a 100644
--- a/resources/src/mediawiki.special/mediawiki.special.watchlist.js
+++ b/resources/src/mediawiki.special/mediawiki.special.watchlist.js
@@ -3,15 +3,7 @@
  */
 ( function ( mw, $, OO ) {
 	$( function () {
-		var $resetForm = $( '#mw-watchlist-resetbutton' ),
-			$progressBar = new OO.ui.ProgressBarWidget( { progress: false } ).$element;
-
-		$progressBar.css( {
-			visibility: 'hidden',
-			position: 'absolute',
-			width: '100%'
-		} );
-		$resetForm.append( $progressBar );
+		var $progressBar, $resetForm = $( '#mw-watchlist-resetbutton' );
 
 		// If the user wants to reset their watchlist, use an API call to do so (no reload required)
 		// Adapted from a user script by User:NQ of English Wikipedia
@@ -19,33 +11,50 @@
 		$resetForm.submit( function ( event ) {
 			event.preventDefault();
 
-			OO.ui.confirm( mw.msg( 'watchlist-mark-all-visited' ) ).done( function ( confirmed ) {
+			OO.ui.confirm( mw.msg( 'watchlist-mark-all-visited' ) )
+			.done( function ( confirmed ) {
 				var $button;
 
-				if ( confirmed ) {
-					// Disable reset button to prevent multiple requests and show progress bar
-					$button = $resetForm.find( 'input[name=mw-watchlist-reset-submit]' ).prop( 'disabled', true );
-					$progressBar.css( 'visibility', 'visible' );
+				if ( !confirmed ) {
+					return;
+				}
 
-					// Use action=setnotificationtimestamp to mark all as visited,
-					// then set all watchlist lines accordingly
-					new mw.Api().postWithToken( 'csrf', {
-						formatversion: 2,
-						action: 'setnotificationtimestamp',
-						entirewatchlist: true
-					} ).done( function () {
-						$button.css( 'visibility', 'hidden' );
-						$progressBar.css( 'visibility', 'hidden' );
-						$( '.mw-changeslist-line-watched' )
-							.removeClass( 'mw-changeslist-line-watched' )
-							.addClass( 'mw-changeslist-line-not-watched' );
-					} ).fail( function () {
-						// On error, fall back to server-side reset
-						// First remove this submit listener and then re-submit the form
-						$resetForm.off( 'submit' ).submit();
-					} );
+				// Disable reset button to prevent multiple requests
+				$button = $resetForm.find( 'input[name=mw-watchlist-reset-submit]' );
+				$button.prop( 'disabled', true );
 
+				// Show progress bar
+				if ( $progressBar ) {
+					$progressBar.css( 'visibility', 'visible' );
+				} else {
+					$progressBar = new OO.ui.ProgressBarWidget( { progress: false } ).$element;
+					$progressBar.css( {
+						position: 'absolute',
+						width: '100%'
+					} );
+					$resetForm.append( $progressBar );
 				}
+
+				// Use action=setnotificationtimestamp to mark all as visited,
+				// then set all watchlist lines accordingly
+				new mw.Api().postWithToken( 'csrf', {
+					formatversion: 2,
+					action: 'setnotificationtimestamp',
+					entirewatchlist: true
+				} ).done( function () {
+					// Enable button again
+					$button.prop( 'disabled', false );
+					// Hide the button because further clicks can not generate any visual changes
+					$button.css( 'visibility', 'hidden' );
+					$progressBar.css( 'visibility', 'hidden' );
+					$( '.mw-changeslist-line-watched' )
+						.removeClass( 'mw-changeslist-line-watched' )
+						.addClass( 'mw-changeslist-line-not-watched' );
+				} ).fail( function () {
+					// On error, fall back to server-side reset
+					// First remove this submit listener and then re-submit the form
+					$resetForm.off( 'submit' ).submit();
+				} );
 			} );
 		} );
 
-- 
2.20.1