Struct ObserverRegistry 

pub struct ObserverRegistry { /* private fields */ }

Registry of component observers that fire on component events.

Observers are runtime-only (not persisted) and must be re-registered each contract invocation. They provide reactive patterns where systems trigger immediately on component changes rather than polling.

Example

use cougr_core::runtime::{ComponentEvent, ObserverRegistry};
use cougr_core::SimpleWorld;
use soroban_sdk::{symbol_short, Env};

fn on_position_added(_event: &ComponentEvent, _world: &SimpleWorld, _env: &Env) {}

let mut registry = ObserverRegistry::new();
registry.on_add(symbol_short!("pos"), on_position_added);
assert_eq!(registry.observer_count(), 1);

Implementations

impl ObserverRegistry

pub fn new() -> Self

Create an empty observer registry.

pub fn on_add( &mut self, component_type: Symbol, observer: fn(event: &ComponentEvent, world: &SimpleWorld, env: &Env), )

Register an observer that fires when a component of the given type is added.

pub fn on_remove( &mut self, component_type: Symbol, observer: fn(event: &ComponentEvent, world: &SimpleWorld, env: &Env), )

Register an observer that fires when a component of the given type is removed.

pub fn fire(&self, event: &ComponentEvent, world: &SimpleWorld, env: &Env)

Fire all matching observers for the given event.

pub fn observer_count(&self) -> usize

Returns the total number of registered observers.

Trait Implementations

impl Default for ObserverRegistry

fn default() -> Self

Returns the “default value” for a type.