How can I get components of an entity?

[rfebbo]

I've seen #3332 but I could not figure out how this solution would fit into my program. I get this error:

&World conflicts with a previous mutable system parameter. Allowing this would break Rust's mutability rules

This is due to including the mutable resources in my system parameters:

fn handle_client_messages(
    mut server: ResMut<QuinnetServer>,
    mut players: ResMut<Players>,
    world: &World,
) {

I've tried just including the world parameter in my system and accessing resources through the World object but I get borrow checker errors.

I've also seen #11587 and tried to use that, but that leads to me borrowing the world multiple times.

    let mut system_state: SystemState<(
        ResMut<QuinnetServer>,
        ResMut<Players>,
    )> = SystemState::new(world);

    let (mut server, mut players) = system_state.get_mut(world);

error[E0502]: cannot borrow `*world` as immutable because it is also borrowed as mutable
   --> src/multiplayer/server_comms.rs:148:37
    |
108 |     let (mut server, mut players) = system_state.get_mut(world);
    |                                                          ----- mutable borrow occurs here
...
125 |                     if let Some(player) = players.map.get_mut(&client_id) {
    |                                           ------- mutable borrow later used here
...
148 |                     let comp_info = world.inspect_entity(entity);
    |                                     ^^^^^ immutable borrow occurs here

I am trying to write a system that can create a list of components of a specific entity for a multiplayer game.

I thought that bevy_reflect might be a good fit for this, but I can't find any guides that align with my problem.

Thanks

[tim-blackbird]

You can use world.resource_scope. Check the linked docs for an example, and keep in mind that you can do multiple nested calls to resource_scope :)

[rfebbo]

This worked! Thanks! And thanks for the hint about nesting, I would've been stuck for sure 😅