1357730 - 'attributeChangedCallback' function no longer firing when observing data attributes

Status: RESOLVED DUPLICATE of bug 1334051

(Core :: DOM: Core & HTML, defect)

Description

[liam.swinney]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Steps to reproduce:

I've created a custom element with the 'attributeChangedCallback' function and added a attribute to the 'observedAttributes'.

The component is ran, however when changing the data attribute, the callback does not fire which it does for none data attributes in Firefox. This works in Chrome and Safari.

The issue was spotted in both Firefox 52.0.2 (64-bit) and 53.0 (64-bit) (Mac), this previously used to work however I cannot get the version it was working in. It was also spotted in Microsoft Edge 38.14393.0.0

Please find the example code below and observe the console. (the version of webcomponent polyfill does not make a difference, I've tried them between 1.0.0-rc.1 and 1.0.0-rc.8)

https://jsfiddle.net/t8rbucvd/7/


Actual results:

The attributeChangedCallback function is not ran when a data attribute is changed


Expected results:

The attributeChangedCallback function should run as per other browsers

Comment 1

[Hsin-Yi Tsai (she/her)[:hsinyi]]

Hey, we had an old implementation for the experimental v0 spec without officially shipping it, and we are now working on the v1 spec implementation. Bug 1334051 is tracking the attributeChanged callback implementation. Thanks!