refactor!: SessionBuilder makes systems + world immutable during session build + Add a rollback-safe world reset utility

Cargo.toml

@@ -30,6 +30,7 @@ parking_lot  = "0.12"
 smallvec     = "1.11"
 ustr         = "0.10"
 iroh-net     = "0.27"
+tracing      = "0.1"
 
 [profile.release]
 lto = true

demos/asset_packs/src/main.rs

@@ -46,12 +46,13 @@ fn main() {
 
     // Create a new session for the game menu. Each session is it's own bones world with it's own
     // plugins, systems, and entities.
-    let menu_session = game.sessions.create("menu");
-    menu_session
+    game.sessions.create_with("menu", |builder| {
         // Install the default bones_framework plugin for this session
-        .install_plugin(DefaultSessionPlugin)
-        // Add our menu system to the update stage
-        .add_system_to_stage(Update, menu_system);
+        builder
+            .install_plugin(DefaultSessionPlugin)
+            // Add our menu system to the update stage
+            .add_system_to_stage(Update, menu_system);
+    });
 
     BonesBevyRenderer::new(game).app().run();
 }

demos/assets_minimal/src/main.rs

@@ -36,13 +36,17 @@ fn main() {
 
     // Create a new session for the game menu. Each session is it's own bones world with it's own
     // plugins, systems, and entities.
-    let menu_session = game.sessions.create("menu");
-    menu_session
-        // Install the default bones_framework plugin for this session
+    let mut menu_session_builder = SessionBuilder::new("menu");
+
+    // Install the default bones_framework plugin for this session
+    menu_session_builder
         .install_plugin(DefaultSessionPlugin)
         // Add our menu system to the update stage
         .add_system_to_stage(Update, menu_system);
 
+    // Finalize session and register with game sessions.
+    menu_session_builder.finish_and_add(&mut game.sessions);
+
     BonesBevyRenderer::new(game).app().run();
 }
 

demos/features/src/main.rs

@@ -125,7 +125,7 @@ pub fn create_game() -> Game {
     TilemapDemoMeta::register_schema();
 
     // Create our menu session
-    game.sessions.create("menu").install_plugin(menu_plugin);
+    game.sessions.create_with("menu", menu_plugin);
 
     game
 }
@@ -139,12 +139,11 @@ struct MenuData {
 }
 
 /// Menu plugin
-pub fn menu_plugin(session: &mut Session) {
+pub fn menu_plugin(session: &mut SessionBuilder) {
     // Register our menu system
     session
         // Install the bones_framework default plugins for this session
         .install_plugin(DefaultSessionPlugin)
-        .world
         // Initialize our menu data resource
         .init_resource::<MenuData>();
 
@@ -198,9 +197,7 @@ fn menu_system(
                         session_options.delete = true;
 
                         // Create a session for the match
-                        sessions
-                            .create("sprite_demo")
-                            .install_plugin(sprite_demo_plugin);
+                        sessions.create_with("sprite_demo", sprite_demo_plugin);
                     }
 
                     if BorderedButton::themed(&meta.button_style, localization.get("atlas-demo"))
@@ -211,9 +208,7 @@ fn menu_system(
                         session_options.delete = true;
 
                         // Create a session for the match
-                        sessions
-                            .create("atlas_demo")
-                            .install_plugin(atlas_demo_plugin);
+                        sessions.create_with("atlas_demo", atlas_demo_plugin);
                     }
 
                     if BorderedButton::themed(&meta.button_style, localization.get("tilemap-demo"))
@@ -224,9 +219,7 @@ fn menu_system(
                         session_options.delete = true;
 
                         // Create a session for the match
-                        sessions
-                            .create("tilemap_demo")
-                            .install_plugin(tilemap_demo_plugin);
+                        sessions.create_with("tilemap_demo", tilemap_demo_plugin);
                     }
 
                     if BorderedButton::themed(&meta.button_style, localization.get("audio-demo"))
@@ -237,9 +230,7 @@ fn menu_system(
                         session_options.delete = true;
 
                         // Create a session for the match
-                        sessions
-                            .create("audio_demo")
-                            .install_plugin(audio_demo_plugin);
+                        sessions.create_with("audio_demo", audio_demo_plugin);
                     }
 
                     if BorderedButton::themed(&meta.button_style, localization.get("storage-demo"))
@@ -250,9 +241,7 @@ fn menu_system(
                         session_options.delete = true;
 
                         // Create a session for the match
-                        sessions
-                            .create("storage_demo")
-                            .install_plugin(storage_demo_plugin);
+                        sessions.create_with("storage_demo", storage_demo_plugin);
                     }
 
                     if BorderedButton::themed(&meta.button_style, localization.get("path2d-demo"))
@@ -263,9 +252,7 @@ fn menu_system(
                         session_options.delete = true;
 
                         // Create a session for the match
-                        sessions
-                            .create("path2d_demo")
-                            .install_plugin(path2d_demo_plugin);
+                        sessions.create_with("path2d_demo", path2d_demo_plugin);
                     }
 
                     if let Some(exit_bones) = &mut exit_bones {
@@ -293,7 +280,7 @@ fn menu_system(
 }
 
 /// Plugin for running the sprite demo.
-fn sprite_demo_plugin(session: &mut Session) {
+fn sprite_demo_plugin(session: &mut SessionBuilder) {
     session
         .install_plugin(DefaultSessionPlugin)
         .add_startup_system(sprite_demo_startup)
@@ -357,7 +344,7 @@ fn move_sprite(
 }
 
 /// Plugin for running the tilemap demo.
-fn tilemap_demo_plugin(session: &mut Session) {
+fn tilemap_demo_plugin(session: &mut SessionBuilder) {
     session
         .install_plugin(DefaultSessionPlugin)
         .add_startup_system(tilemap_startup_system)
@@ -403,7 +390,7 @@ fn tilemap_startup_system(
 }
 
 /// Plugin for running the atlas demo.
-fn atlas_demo_plugin(session: &mut Session) {
+fn atlas_demo_plugin(session: &mut SessionBuilder) {
     session
         .install_plugin(DefaultSessionPlugin)
         .add_startup_system(atlas_demo_startup)
@@ -451,7 +438,7 @@ fn atlas_demo_startup(
     );
 }
 
-fn audio_demo_plugin(session: &mut Session) {
+fn audio_demo_plugin(session: &mut SessionBuilder) {
     session
         .install_plugin(DefaultSessionPlugin)
         .add_system_to_stage(Update, back_to_menu_ui)
@@ -477,7 +464,7 @@ fn audio_demo_ui(
         });
 }
 
-fn storage_demo_plugin(session: &mut Session) {
+fn storage_demo_plugin(session: &mut SessionBuilder) {
     session
         .install_plugin(DefaultSessionPlugin)
         .add_system_to_stage(Update, storage_demo_ui)
@@ -507,7 +494,7 @@ fn storage_demo_ui(
     });
 }
 
-fn path2d_demo_plugin(session: &mut Session) {
+fn path2d_demo_plugin(session: &mut SessionBuilder) {
     session
         .install_plugin(DefaultSessionPlugin)
         .add_startup_system(path2d_demo_startup)
@@ -558,7 +545,7 @@ fn back_to_menu_ui(
                 ui.add_space(20.0);
                 if ui.button(localization.get("back-to-menu")).clicked() {
                     session_options.delete = true;
-                    sessions.create("menu").install_plugin(menu_plugin);
+                    sessions.create_with("menu", menu_plugin);
                 }
             });
         });

demos/hello_world/src/main.rs

@@ -10,12 +10,13 @@ fn main() {
 
     // Create a new session for the game menu. Each session is it's own bones world with it's own
     // plugins, systems, and entities.
-    let menu_session = game.sessions.create("menu");
-    menu_session
-        // Install the default bones_framework plugin for this session
-        .install_plugin(DefaultSessionPlugin)
-        // Add our menu system to the update stage
-        .add_system_to_stage(Update, menu_system);
+    game.sessions.create_with("menu", |session| {
+        session
+            // Install the default bones_framework plugin for this session
+            .install_plugin(DefaultSessionPlugin)
+            // Add our menu system to the update stage
+            .add_system_to_stage(Update, menu_system);
+    });
 
     BonesBevyRenderer::new(game).app().run();
 }

demos/scripting/src/main.rs

@@ -22,9 +22,9 @@ fn main() {
         .register_default_assets();
     GameMeta::register_schema();
 
-    game.sessions
-        .create("launch")
-        .add_startup_system(launch_game_session);
+    game.sessions.create_with("launch", |builder| {
+        builder.add_startup_system(launch_game_session);
+    });
 
     let mut renderer = BonesBevyRenderer::new(game);
     renderer.app_namespace = (
@@ -41,15 +41,17 @@ fn launch_game_session(
     mut session_ops: ResMut<SessionOptions>,
 ) {
     session_ops.delete = true;
-    let game_session = sessions.create("game");
-    game_session
-        .install_plugin(DefaultSessionPlugin)
-        // Install the plugin that will load our lua plugins and run them in the game session
-        .install_plugin(LuaPluginLoaderSessionPlugin(
-            // Tell it to install the lua plugins specified in our game meta
-            Arc::new(meta.plugins.iter().copied().collect()),
-        ))
-        .add_startup_system(game_startup);
+    // Build game session and add to `Sessions`
+    sessions.create_with("game", |builder| {
+        builder
+            .install_plugin(DefaultSessionPlugin)
+            // Install the plugin that will load our lua plugins and run them in the game session
+            .install_plugin(LuaPluginLoaderSessionPlugin(
+                // Tell it to install the lua plugins specified in our game meta
+                Arc::new(meta.plugins.iter().copied().collect()),
+            ))
+            .add_startup_system(game_startup);
+    });
 }
 
 fn game_startup(

framework_crates/bones_asset/Cargo.toml

@@ -40,7 +40,7 @@ serde           = { version = "1.0", features = ["derive"] }
 serde_json      = "1.0"
 serde_yaml      = "0.9"
 sha2            = "0.10"
-tracing         = "0.1"
+tracing         = { workspace = true }
 ulid            = "1.0"
 ustr            = { workspace = true }
 

framework_crates/bones_ecs/Cargo.toml

@@ -40,6 +40,7 @@ atomicell   = "0.2"
 bitset-core = "0.1"
 once_map    = "0.4.12"
 thiserror   = "1.0"
+tracing     = { workspace = true }
 
 [dev-dependencies]
 glam = "0.24"

framework_crates/bones_ecs/examples/pos_vel.rs

@@ -22,15 +22,18 @@ fn main() {
     // Initialize an empty world
     let mut world = World::new();
 
-    // Create a SystemStages to store the systems that we will run more than once.
-    let mut stages = SystemStages::with_core_stages();
+    // Build SystemStages to store the systems that we will run more than once.
+    let mut stages_builder = SystemStagesBuilder::with_core_stages();
 
     // Add our systems to the system stages
-    stages
+    stages_builder
         .add_startup_system(startup_system)
         .add_system_to_stage(CoreStage::Update, pos_vel_system)
         .add_system_to_stage(CoreStage::PostUpdate, print_system);
 
+    // Finish build to get `SystemStages`.
+    let mut stages = stages_builder.finish();
+
     // Run our game loop for 10 frames
     for _ in 0..10 {
         stages.run(&mut world);