HTML attributes can be a very powerful tool to extend a page's DOM with all kinds of nifty features. Mostly used for adding accessibility features for screen readers (ARIA, etc.), they can also be used to create custom locators for use in test automation and the like.
At the moment, the only way to add (custom) HTML attributes is by using the Accessibility Helper widget. Using that widget is fine, when you only need to use it once or twice on a page, but the widget is pretty big and starts to clutter the page model once you use it more extensively.
That's why I would like to suggest making adding (custom) HTML attributes a native feature of Mendix Studio Pro. It could be comparable to the way inline styling (please, don't use inline styling!!) is possible, with a single text box/area for adding the attributes and their value(s), or with a proper key/value editor like the way the accessibility helper widget itself does it. The second way also would permit dynamic values, which would be awesome
>locators [...] for use in [...] automated testings
Yes, improving the (functional) testability of Mendix apps! Another gripe of mine... ;)
> one widget changing the behaviour of another
There's that as well, yes, which would also be solved by having an HTML attribute editor in each widget.
> How would you solve the problem of addressing specific HTML elements?
Do you mean things like the individual options in a select element, for example? That's a biggie, and I think it's something that is not easily solvable, as that would mean breaking open to expose the internal workings of a widget to Studio Pro... Not sure if and how that would be possible...
Generally a nice idea. I also don't really like the approach of having one widget changing the behaviour of another (like the Accessibility helper does)
How would you solve the problem of addressing specific HTML elements?
Widgets consist of multiple html elements and you might need to affect other elements than just the root of the widget (It's the same problem you already have with the styling property).
Yes please, these locators would be an awesome addition for use in our automated testings!