Allow UI plugins to customise the content header

[chris-steele]

Feature description

I developed a UI plugin that needed to add a new button to the content header buttons. I found there was no API or event that I could use to know when the content header buttons had been (re-)rendered. I therefore had to use a DOM mutation observer to know when to add in my custom button. This is a rather fragile solution.

Perhaps we could introduce something like the navigation API as per the framework?

Can you work on this feature?

• I can contribute

[taylortom]

Sounds very reasonable. I think we need a wider discussion about introducing this kind of think into v1.1