<img> srcset attribute is stripped when switching from text to visual tab in the editor

[kirillcool]

Going to the "text" tab to add srcset attribute (manually) to the image, and then going to "visual" tab results in that attribute being stripped out.

[terminalpixel]

I can confirm this occurs on a clean install of 4.0

[sabreuse]

+1 to this -- now that the spec is settled and support is out in the wild in FF and Chrome, I'd love to be able to start using srcsets natively.

[mattheu]

+1

I think this issue should probably be fixed upstream in TinyMCE itself - I have opened a pull request on github to add this - ​https://github.com/tinymce/tinymce/pull/428

In the mean time - heres a patch that fixes it.

Note - I have also done this in the past by adding it to valid_elements using the tiny_mce_before_init filter, but I think it would be best to avoid doing this in core.

[mattheu]

Also opened PR for TinyMCE for picture element support as this is related: ​https://github.com/tinymce/tinymce/pull/429

[azaozz]

Currently there is partial support for srcset, although most browsers that run on high pixel density devices support it. Asked upstream.

However only Chrome and Opera support <picture> (no mobile browsers support), and it seems it still has some problems/uncertainties. Perhaps better to wait few more months before trying to use it.

[spocke]

We merged in both pull requests. So srcset and picture elements should work as of 4.1.7. Thanks mattheu for helping out.

[azaozz]

Thanks @spocke. This will be in WordPress 4.1 after we update TinyMCE.

[azaozz]

Fixed in [30397].