Nodes around UI entities

[hydroper]

I wonder if it could make sense to have nodes (probably atomically-reference-counted) around UI entities because the existing use of spawning and unspawning commands supports no children operations, such as finding child by path (whether ../child_id/blah), getting a child's path. Consider:

• Godot nodes
  • Node paths are similiar to Unix paths, consisting of slashes, dots, .. and names
• Angular's components
  • Have their template's host element as an ordinary custom HTML element.
  • Can manipulate elements contained within the template (such as @ViewModel(...) elementRef: ElementRef; and elementRef.nativeElement).

I think this is a way to implement nodes in Rust with composition instead of traits for avoiding dynamic dispatch on complementary fields:

Summary:

• Node avoids contravariant methods. For example, if set_foo belongs to Foo variant, generally Node doesn't define it.
• Node implements From<K> (so a contravariant type can convert into Node by simply .into()).
• 3 macros are defined using the syn crate: markup!, define_node! and define_ui_component!.
• define_node! defines a node kind, which holds (node, data), inheriting everything from node, implicitly
  defining set_ methods for attributes used in the markup! macro. data is of the hidden K__Internal type.
• to::<K>, try_into::<K> and .is::<K> are supported by Node.

[hydroper]

I think this doesn't fit with Bevy after looking at bevy::hierarchy. I think there are no "entity paths" in this sense, but I'm not sure it's necessary

[nicopap]

Bevy has "entity paths". It's used in bevy_animation. Simply add a Name component to the entities in the path. The path components are the name of each entity in the hierarchy. But nodes as you describe it have little to do with ECS. You seem to describe an OOP game system. Which is incompatible with rust, as rust has no concept of inheritance (and for good reasons!). It's not impossible to create fake inheritance in rust (as your link demonstrates), but it is complex and you won't gain anything from it. I invite you to approach bevy without preconceptions. It helps to think of Rust as a non-OOP language.

[hydroper]

@nicopap Interesting, but I've not found any way to get a child entity by a path anywhere