wmode only applies to Flash content

[dd8]

https://alphagov.github.io/accessibility-tool-audit/tests/html-object-not-embedded-accessibly-wmode-parameter-not-set-to-window.html

This test is ambiguous because wmode=transparent is only an issue if data="foo" refers to an SWF movie, because wmode is a proprietary Adobe parameter for Flash player.

Here's Adobe's wmode documentation:
https://helpx.adobe.com/flash/kb/flash-object-embed-tag-attributes.html#main_Browser_support_for_Window_Mode__wmode__values

So this is definitely an issue:

<object type="application/x-shockwave-flash" data="movie_name.swf" width="550" height="400">
        <param name="wmode" value="transparent" />
        Alternative text
</object>

this is definitely not an issue:

<!-- not Flash content: wmode has no effect -->
<object data="clock.html" type="text/html">
        <param name="wmode" value="transparent" />
        Alternative text
</object>

and this depends on whether data="foo" is an SWF file:

<!-- wmode has no effect unless "foo" is an SWF file -->
<object data="foo">
        <param name="wmode" value="transparent" />
        Alternative text
</object>

[selfthinker]

I'd be in favour of dropping this test altogether. Do we know if this is actually still a problem? Does anyone still use Flash?

But yes, good point. The "foo" was just a lazy way of not needing to search for and upload a Flash file.

[dd8]

Dropping it makes sense, since Adobe have announced end of life for Flash in 2020, and browser vendors have been gradually making it harder to activate Flash content since 2017
https://theblog.adobe.com/adobe-flash-update/

Flash is already disabled by default in Safari on macOS High Sierra

Firefox will disable Flash by default in 2019
https://developer.mozilla.org/en-US/docs/Plugins/Roadmap

Chrome will disable Flash by default in July 2019
https://www.chromium.org/flash-roadmap

Edge and IE are disabling Flash by default in mid-to-late 2019
https://blogs.windows.com/msedgedev/2017/07/25/flash-on-windows-timeline/

According to these stats, Flash usage is down to 0.01% (data set is 16 billion web sites)
https://trends.builtwith.com/framework/Flash