Content-aware component containers

[vaadin-miki]

Create component(s) that fire events when something is added or removed to them, regardless of the level of nesting.

Use case: a layout into which components are added should fire events when something has been added or removed from it.

Mutation observers seem to be a good approach, as detailed in https://stackoverflow.com/questions/2844565/is-there-a-javascript-jquery-dom-change-listener

[vaadin-miki]

it seems that client-side nodes cannot be passed to server-side (causing an error about endless recursion); this means that the first implementation will just report that there have been changes to the dom and nothing else

a simple workaround for finding objects on the server would be to register them with content-aware before they are physically added (e.g. by setting a property of that new object, getting it on the client and then passing that to the server) - this defeats the purpose of content awareness, though

maybe there exists a better way? it seems near impossible to figure out a server-side object from a client-side component, but perhaps I am missing something?