Add custom attributes support, e.g. 'data-X'

I don't know of similar solutions. But the Webform module builds the controls from Yaml (the render array is created with Yaml::decode). It allows you to specify any attributes for an element and its wrapper in Yaml syntax.

I don't know why it might be unsafe. The attributes are stored in the configuration and are typed as a string. They are also passed to the element's #attributes and will be parsed/escaped on output like all other attributes.

Thanks @kay64, we have a similar request in https://www.drupal.org/project/menu_link_attributes/issues/3325692#comme... ✨ Add custom attributes support, e.g. 'download' Closed: cannot reproduce

One solution I thought about was a submodule to define the usable custom attributes in a setting and provide the value in each field. yaml is another option, which isn't bad, but not good UX for non-tech site builders.

So I'd prefer the submodule custom attribute definition thing. Seems to be a quite general requirements for such kind of modules?

Thinking about this for a while, I think the suggested MR by @kay64 is nice and smart. @kay64 could you please add an example as placeholder or in the description, for example for a "download" or a data attribute?

The module Layout Builder Component Attributes → has a similar functionality for date attributes, implemented in much the same way.

Added an example of modal window settings. There is also an example of usage in the textarea description.

Super cool, thank you @kay64! We should now check the security of this approach and best would be to have some automated tests, then this is ready to go from my side!

kksandr → closed merge request !6

I added tests, but I changed the way of testing, the presence of attributes is checked in the markup via DOMDocument.

Thanks @kksandr! Looking good, but needs to be reworked now.