Added query_world function that behaves a bit like a system.

Cargo.lock

@@ -1841,6 +1841,7 @@ name = "kayak_core"
 version = "0.1.0"
 dependencies = [
  "as-any",
+ "bevy",
  "derivative",
  "flo_binding",
  "kayak_render_macros",

Cargo.toml

@@ -9,7 +9,12 @@ members = ["bevy_kayak_ui", "kayak_core", "kayak_render_macros", "kayak_font"]
 
 [features]
 default = ["bevy_renderer"]
-bevy_renderer = ["bevy_kayak_ui", "kayak_font", "bevy"]
+bevy_renderer = [
+    "bevy_kayak_ui",
+    "kayak_font",
+    "kayak_core/bevy_renderer",
+    "bevy",
+]
 
 [dependencies]
 bevy = { git = "https://github.com/bevyengine/bevy", rev = "9a16a4d01830297987db40b45f03382ed3acad62", optional = true }

examples/global_counter.rs

@@ -12,17 +12,8 @@ struct GlobalCount(pub u32);
 
 #[widget]
 fn Counter(context: &mut KayakContext) {
-    let global_count = {
-        if let Ok(world) = context.get_global_state::<World>() {
-            if let Some(global_count) = world.get_resource::<Binding<GlobalCount>>() {
-                global_count.clone()
-            } else {
-                return;
-            }
-        } else {
-            return;
-        }
-    };
+    let global_count = context
+        .query_world::<Res<Binding<GlobalCount>>, _, _>(move |global_count| global_count.clone());
 
     context.bind(&global_count);
 

kayak_core/Cargo.toml

@@ -7,10 +7,12 @@ edition = "2021"
 
 [features]
 default = []
+bevy_renderer = ["bevy"]
 
 [dependencies]
 as-any = "0.2"
 derivative = "2.2"
+bevy = { git = "https://github.com/bevyengine/bevy", rev = "9a16a4d01830297987db40b45f03382ed3acad62", optional = true }
 flo_binding = { git = "https://github.com/StarArawn/flo_binding.git", rev = "c78431a56df5ec082b7e1c271871e6c0ac75e81e" }
 kayak_render_macros = { path = "../kayak_render_macros" }
 morphorm = { git = "https://github.com/geom3trik/morphorm", rev = "1243152d4cebea46fd3e5098df26402c73acae91" }

kayak_core/src/context.rs

@@ -528,4 +528,20 @@ impl KayakContext {
             self.get_all_parents(*parent, parents);
         }
     }
+
+    #[cfg(feature = "bevy_renderer")]
+    pub fn query_world<T: bevy::ecs::system::SystemParam, F, R>(&mut self, mut f: F) -> R
+    where
+        F: FnMut(<T::Fetch as bevy::ecs::system::SystemParamFetch<'_, '_>>::Item) -> R,
+    {
+        let mut world = self.get_global_state::<bevy::prelude::World>().unwrap();
+        let mut system_state = bevy::ecs::system::SystemState::<T>::new(&mut world);
+        let r = {
+            let test = system_state.get_mut(&mut world);
+            f(test)
+        };
+        system_state.apply(&mut world);
+
+        r
+    }
 }