This commit fixes an issue where a node's event handlers would stop
working if you added or removed DOM elements before that node in certain
ways.
We've added test cases and changed our event handling implementation
to handle these scenarios.
The problem was that when we created new real DOM elements we gave them a
property .__events_id__ = NodeIdx where NodeIdx was its index in the
virtual-dom at the time of creation.
Then when you triggered an event on that element we would look up its
events using that node idx.
The problem with that is that once you add/remove virtual nodes before it
in the virtual tree, the node idx is no longer correct.
The new implementation added in this commit uses unique identifiers to
look up the events. So, on the real DOM element we now set
.__events_id__ = SomeUniqueId and we maintain a map of (pseudocode)
HashMap<SomeUniqueId, Rc<RefCell<SomeEvents>>.
Alongside this we maintain a tree of SomeUniqueId's that we add/remove
to during the same function that add/remove's to the real DOM tree.
This lets us know whifh SomeUniqueId corresponds to the NodeIdx so
that at the end of patching we can update the Rc<RefCell<SomeEvents>>
for the correct dom element.
This commit fixes an issue where a node's event handlers would stop working if you added or removed DOM elements before that node in certain ways.
We've added test cases and changed our event handling implementation to handle these scenarios.
The problem was that when we created new real DOM elements we gave them a property
.__events_id__ = NodeIdxwhere NodeIdx was its index in the virtual-dom at the time of creation.Then when you triggered an event on that element we would look up its events using that node idx.
The problem with that is that once you add/remove virtual nodes before it in the virtual tree, the node idx is no longer correct.
The new implementation added in this commit uses unique identifiers to look up the events. So, on the real DOM element we now set
.__events_id__ = SomeUniqueIdand we maintain a map of (pseudocode)HashMap<SomeUniqueId, Rc<RefCell<SomeEvents>>.Alongside this we maintain a tree of
SomeUniqueId's that we add/remove to during the same function that add/remove's to the real DOM tree.This lets us know whifh
SomeUniqueIdcorresponds to theNodeIdxso that at the end of patching we can update theRc<RefCell<SomeEvents>>for the correct dom element.