Proper type for function that returns EntityCommands

[cyan fiber]

I have this code:

fn build(
        &self,
        transform: Transform,
        commands: &mut Commands,
    ) -> &mut bevy::ecs::system::EntityCommands {
        commands
            .spawn()
            .insert_bundle(self.components[0].spawn(transform))
            .with_children(|parent| {
                for component in &self.components[1..] {
                    &mut parent
                        .spawn()
                         // I actually had the exact same issue with this component.spawn() function but in that case I can just return a bundle since it's used only here. However, this build function needs a lot more uses so that would be impractical. Also returning a bundle won't let me add children
                        .insert_bundle(component.spawn(Transform::default()));
                }
                if let Some((collider, offset)) = self.collider {
                    parent
                        .spawn_bundle(TransformBundle {
                            local: Transform::from_translation(offset),
                            ..default()
                        })
                        .insert(collider.clone());
                }
            })
    }

But I'm getting lifetime errors. What I basically want to do is have a function that creates a component and adds some children and bundles to it, but then also exposes it so the calling code can maybe add more components or children.

Is there a way to either 1) Fix the lifetimes here or 2) expose the ability to add more components in a totally different way

[sand rune]

Not sure if this is right or not, but here's what I ended up doing:

fn spawn<'a, 'p, 'w, 's>(
  &'p self,
  commands: &'a mut Commands<'w, 's>,
) -> EntityCommands<'w, 's, 'a>
where
  Self: Asset + Sized,
{
  let entity = commands.spawn().id();
  self.insert(entity, commands)
}

https://github.com/MrGVSV/bevy_proto/blob/86d5ff1b46fb40f006cb26a1e0fc4efc83fb23ab/src/prototypical.rs#L57-L66

[elder pewter]

I'm trying to do something similar to the above, except I want to have a I want to take a &mut ChildBuilder as a parameter, along with, say, Color and Style, to spawn a NodeBundle. The lifetimes are drivingme up the wall.