Make YoleckEntityRef::resolve failable

Author: idanarye

assets/levels2d/example.yol

@@ -1 +1 @@
-[{"format_version":2,"app_format_version":1},{},[[{"type":"FloatingText","name":""},{"LaserPointer":{"target":null},"TextContent":{"text":"Collect the fruit"},"Vpeol2dPosition":[118.0838623046875,306.9156494140625],"Vpeol2dScale":[1.0,1.0]}],[{"type":"FloatingText","name":""},{"LaserPointer":{"target":"e8f8d516-ca5f-41d2-99a6-1be029fdd0ee"},"TextContent":{"text":"Orange"},"Vpeol2dPosition":[74.51683044433594,-226.31687927246094],"Vpeol2dScale":[0.75,0.75]}],[{"type":"Triangle","name":""},{"TriangleVertices":{"vertices":[[-12.283805847167969,-141.28375244140625],[211.94580078125,-151.37274169921875],[199.81985473632812,16.863494873046875]]},"Vpeol2dPosition":[-459.87017822265625,-29.312294006347656]}],[{"type":"Player","name":""},{"Vpeol2dPosition":[-309.3874206542969,81.44441223144531],"Vpeol2dRotatation":0.0}],[{"type":"Fruit","name":"","uuid":"eb26f293-7548-4bcc-a268-871c80726fd3"},{"FruitType":{"index":2},"Vpeol2dPosition":[-264.37799072265625,-226.1751708984375]}],[{"type":"Fruit","name":"","uuid":"e8f8d516-ca5f-41d2-99a6-1be029fdd0ee"},{"FruitType":{"index":1},"Vpeol2dPosition":[-3.697650909423828,-60.341732025146484]}],[{"type":"FloatingText","name":""},{"LaserPointer":{"target":"eb26f293-7548-4bcc-a268-871c80726fd3"},"TextContent":{"text":"Grapes"},"Vpeol2dPosition":[-440.10369873046875,-230.0904998779297],"Vpeol2dScale":[0.75,0.75]}]]]
+[{"format_version":2,"app_format_version":1},{},[[{"type":"Player","name":""},{"Vpeol2dPosition":[-309.3874206542969,81.44441223144531],"Vpeol2dRotatation":0.0}],[{"type":"Triangle","name":""},{"TriangleVertices":{"vertices":[[-12.283805847167969,-141.28375244140625],[211.94580078125,-151.37274169921875],[199.81985473632812,16.863494873046875]]},"Vpeol2dPosition":[-459.87017822265625,-29.312294006347656]}],[{"type":"FloatingText","name":"","uuid":"8acaa597-8c7d-4b82-8fd5-4eda44e24b5f"},{"TextContent":{"text":"Collect the fruit"},"TextLaserPointer":{"target":{}},"Vpeol2dPosition":[118.0838623046875,306.9156494140625],"Vpeol2dScale":[1.0,1.0]}],[{"type":"FloatingText","name":"","uuid":"14195c3b-e420-4fa4-bc59-7149a7c7f5d4"},{"TextContent":{"text":"Orange"},"TextLaserPointer":{"target":{"uuid":"e8f8d516-ca5f-41d2-99a6-1be029fdd0ee"}},"Vpeol2dPosition":[74.51683044433594,-226.31687927246094],"Vpeol2dScale":[0.75,0.75]}],[{"type":"Fruit","name":"","uuid":"e8f8d516-ca5f-41d2-99a6-1be029fdd0ee"},{"FruitType":{"index":1},"Vpeol2dPosition":[-3.697650909423828,-60.341732025146484]}],[{"type":"Fruit","name":"","uuid":"eb26f293-7548-4bcc-a268-871c80726fd3"},{"FruitType":{"index":2},"Vpeol2dPosition":[-265.73712158203125,-226.1751708984375]}],[{"type":"FloatingText","name":"","uuid":"e9f7c89f-f975-41e0-9ab0-30991e715877"},{"TextContent":{"text":"Grapes"},"TextLaserPointer":{"target":{"uuid":"eb26f293-7548-4bcc-a268-871c80726fd3"}},"Vpeol2dPosition":[-440.10369873046875,-230.0904998779297],"Vpeol2dScale":[0.75,0.75]}]]]

examples/example2d.rs

@@ -583,7 +583,7 @@ fn resolve_laser_pointers(
     uuid_registry: Res<YoleckUuidRegistry>,
 ) {
     for mut laser_pointer in query.iter_mut() {
-        laser_pointer.target.resolve(&uuid_registry);
+        let _ = laser_pointer.target.resolve(&uuid_registry);
     }
 }
 
@@ -593,14 +593,14 @@ fn draw_laser_pointers(
     mut gizmos: Gizmos,
 ) {
     for (laser_pointer, source_transform) in query.iter() {
-        if let Some(target_entity) = laser_pointer.target.entity() {
-            if let Ok(target_transform) = targets_query.get(target_entity) {
-                gizmos.line(
-                    source_transform.translation(),
-                    target_transform.translation(),
-                    css::GREEN,
-                );
-            }
+        if let Some(target_entity) = laser_pointer.target.entity()
+            && let Ok(target_transform) = targets_query.get(target_entity)
+        {
+            gizmos.line(
+                source_transform.translation(),
+                target_transform.translation(),
+                css::GREEN,
+            );
         }
     }
 }

examples/example3d.rs

@@ -283,7 +283,7 @@ fn resolve_laser_pointers(
     uuid_registry: Res<YoleckUuidRegistry>,
 ) {
     for mut laser_pointer in query.iter_mut() {
-        laser_pointer.target.resolve(&uuid_registry);
+        let _ = laser_pointer.target.resolve(&uuid_registry);
     }
 }
 
@@ -293,14 +293,14 @@ fn draw_laser_pointers(
     mut gizmos: Gizmos,
 ) {
     for (laser_pointer, source_transform) in query.iter() {
-        if let Some(target_entity) = laser_pointer.target.entity() {
-            if let Ok(target_transform) = targets_query.get(target_entity) {
-                gizmos.line(
-                    source_transform.translation(),
-                    target_transform.translation(),
-                    css::LIMEGREEN,
-                );
-            }
+        if let Some(target_entity) = laser_pointer.target.entity()
+            && let Ok(target_transform) = targets_query.get(target_entity)
+        {
+            gizmos.line(
+                source_transform.translation(),
+                target_transform.translation(),
+                css::LIMEGREEN,
+            );
         }
     }
 }

src/entity_ref.rs

@@ -3,6 +3,7 @@ use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
 use crate::entity_uuid::YoleckUuidRegistry;
+use crate::errors::YoleckEntityRefCannotBeResolved;
 
 /// A reference to another Yoleck entity, stored by UUID for persistence.
 ///
@@ -98,12 +99,19 @@ impl YoleckEntityRef {
         self.resolved = None;
     }
 
-    pub fn resolve(&mut self, registry: &YoleckUuidRegistry) {
+    pub fn resolve(
+        &mut self,
+        registry: &YoleckUuidRegistry,
+    ) -> Result<(), YoleckEntityRefCannotBeResolved> {
         if let Some(uuid) = self.uuid {
             self.resolved = registry.get(uuid);
+            if self.resolved.is_none() {
+                return Err(YoleckEntityRefCannotBeResolved { uuid });
+            }
         } else {
             self.resolved = None;
         }
+        Ok(())
     }
 }
 

src/errors.rs

@@ -1,4 +1,5 @@
 use bevy::ecs::error::BevyError;
+use uuid::Uuid;
 
 #[derive(thiserror::Error, Debug)]
 pub(crate) enum YoleckAssetLoaderError {
@@ -18,3 +19,9 @@ impl From<BevyError> for YoleckAssetLoaderError {
         Self::Bevy(value)
     }
 }
+
+#[derive(thiserror::Error, Debug)]
+#[error("{uuid} does not resolve to any known entity in the registry")]
+pub struct YoleckEntityRefCannotBeResolved {
+    pub uuid: Uuid,
+}