API Deprecations and Removals in Chrome 51

In nearly every version of Chrome we see a significant number of updates and improvements to the product, its performance, and also capabilities of the web platform.

Deprecation policy

To keep the platform healthy we sometimes remove APIs from the Web Platform which have run their course. There can be many reasons why we would remove an API, such as: they are superseded by newer APIs, are updated to reflect changes to specifications, to bring alignment and consistency with other browsers, or they are early experiments that never came to fruition in other browsers and thus can increase the burden of support for web developers.

Some of these changes might have an effect on a very small number of sites and to mitigate issues ahead of time we try to give developers advanced notice so that if needed they can make the required changes to keep their sites running.

Chrome currently has a process for deprecations and removals of APIs and the TL;DR is:

  • Announce on blink-dev
  • Set warnings and give time scales in the developer console of the browser when usage is detected on a page
  • Wait, monitor and then remove feature as usage drops

You can find a list of all deprecated features in chromestatus.com using the deprecated filter and removed features by applying the removed filter. We will also try to summarize some of the changes, reasoning, and migration paths in these posts.

In Chrome 51 (April, 2016) there are a number of changes to Chrome.

Remove Custom Messages in onbeforeload Dialogs

TL;DR: A window’s onbeforeload property no longer supports a custom string.

Intent to Remove | Chromestatus Tracker | Chromium Bug

A window’s onbeforeunload property may be set to a function that returns a string that is shown to the user in a dialog box to confirm that the user wants to navigate away. This was intended to prevent users from losing data during navigation. Unfortunately, it is often used to scam users.

Starting in Chrome 51, a custom string will no longer be shown to the user. Chrome will still show a dialog to prevent users from losing data, but it’s contents will be set by the browser instead of the web page.

With this change, Chrome will be consistent with Safari 9.1 and later, as well as Firefox 4 and later.

Deprecated results attribute for <input type=search>

TL;DR: The result attribute is being deprecated because it’s not part of any standard and it inconsistently implemented across browsers.

Intent to Remove | Chromestatus Tracker | Chromium Bug

The results is not implemented on most browser and highly inconsistently on those that do. For example, Chrome responds by adding a magnifier icon to the input box. While Safari desktop , it controls how many submitted queries are shown in a popup shown by click the magnifier icon. Since this isn’t part of any standard, it’s being deprecated.

Removal is expected in Chrome 53.

Originally published on Web Updates — Google Developers

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