tutorial: plugins

src/main.rs

@@ -2,8 +2,7 @@ use bevy::prelude::*;
 
 fn main() {
     App::new()
-        .add_systems(Startup, add_people)
+        .add_plugins((DefaultPlugins, HelloPlugin))
-        .add_systems(Update, (hello_world, greet_people))
         .run();
 }
 
@@ -19,6 +18,15 @@ fn add_people(mut commands: Commands) {
     commands.spawn((Person, Name("Zayna Nieves".to_string())));
 }
 
+fn update_people(mut query: Query<&mut Name, With<Person>>) {
+    for mut name in &mut query {
+        if name.0 == "Elaina Proctor" {
+            name.0 = "Elaina Hume".to_string();
+            break;
+        }
+    }
+}
+
 fn greet_people(query: Query<&Name, With<Person>>) {
     for name in &query {
         println!("hello {}!", name.0);
@@ -28,3 +36,11 @@ fn greet_people(query: Query<&Name, With<Person>>) {
 fn hello_world() {
     println!("hello world!");
 }
+
+pub struct HelloPlugin;
+impl Plugin for HelloPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, add_people)
+            .add_systems(Update, (hello_world, (update_people, greet_people).chain()));
+    }
+}