I’ve a question about such addon.
The xml syntax is the same was used with Vaadin 8 ?
Is there any documentation about that syntax and about limitations ?
Tks
Even though the syntax is ultimately very similar, you shouldn’t expect to copy over your layouts from Vaadin 8 and have them work as is. It’s just that the way this add-on works on a technical level is much much closer to how DUI in Vaadin 8 worked than to how Polymer / Lit templates work.
Syntax-wise, the intention was to be as close as possible to the HTML syntax of Vaadin’s latest components, but still implement useful extensions that were still possible in Vaadin 8.
E.g. the size-full from the following snippet was possible in Vaadin 8 but no longer works in Polymer/Lit templates (you’d have to use CSS now). However, using my add-on it’s possible again:
<vaadin-vertical-layout size-full>...</vaadin-vertical-layout>.
Anyway, you can read a bit more on the [GitLab project page]
(https://gitlab.com/codecamp-de/vaadin-flow-dui) on what the initial intention of the add-on was. There’s also a list of the currently supported components and attributes.
The two major show stoppers (for me) that triggered me to start this add-on in the first place, have been fixed/removed by Vaadin in the meantime. So to me using a Lit template is a valid option now and this add-on is no longer as essential as it was initially. But especially if you are working on a Java-only Vaadin project this add-on can still provide a lot of flexibility that you wouldn’t have otherwise, if you need it. By implementing ComponentFactory and ComponentPostProcessor you can basically extend or change the syntax in any way you need. E.g. you could implement that adding an attribute l10n-key="myMessageKey" to a <vaadin-button> automatically localizes its label.
There’s value in sticking with default mechanisms (i.e. Lit templates) as more people that might join your project will be familiar with them instead of with some niche add-on like this and the specific extensions you might implement on top of it. So there’s definitely a bit to consider and evaluate when deciding if and how to use this add-on.
But for now I think it still has enough potential to not just abandon it :)