optimize

src/compiler/compile/render_dom/Block.ts

@@ -59,7 +59,7 @@ export default class Block {
 		destroy: Array<Node | Node[]>;
 	};
 
-	event_updaters: ({condition:Expression, snippet:Node, index:number})[] = [];
+	event_updaters: ({condition:Expression, index:number})[] = [];
 	event_listeners: Node[] = [];
 
 	maintain_context: boolean;
@@ -484,12 +484,9 @@ export default class Block {
 				);
 
 				if (this.event_updaters.length === 1) {
-					const {condition, snippet} = this.event_updaters[0];
+					const {condition} = this.event_updaters[0];
 					this.chunks.update.push(b`
-					if (${condition}) {
+					if (${condition}) ${dispose}.p()`);
-						${dispose}.swap(${snippet})
-					}`
-					);
 				}
 
 				this.chunks.destroy.push(
@@ -505,12 +502,8 @@ export default class Block {
 					}
 				`);
 
-				for (const {condition, snippet, index} of this.event_updaters) {
+				for (const {condition, index} of this.event_updaters) {
-					this.chunks.update.push(b`
+					this.chunks.update.push(b` if (${condition}) ${dispose}[${index}].p()`);
-					if (${condition}) {
-						${dispose}[${index}].swap(${snippet})
-					}`
-					);
 				}
 
 				this.chunks.destroy.push(

src/compiler/compile/render_dom/wrappers/Element/EventHandler.ts

@@ -69,9 +69,9 @@ export default class EventHandlerWrapper {
 			const index = block.event_listeners.length;
 			const condition = block.renderer.dirty(this.node.expression.dynamic_dependencies());
 
-			block.event_updaters.push({condition, snippet, index});
+			block.event_updaters.push({condition, index});
 			block.event_listeners.push(
-				x`@listen_swap(${snippet}, (h)=> ${listen}(${target}, "${this.node.name}", h, ${args}))`
+				x`@listen_and_update( () => (${snippet}), (h) => ${listen}(${target}, "${this.node.name}", h, ${args}))`
 			);
 		} else {
 			block.event_listeners.push(

src/runtime/internal/dom.ts

@@ -273,16 +273,19 @@ export function listen(node: EventTarget, event: string, handler: EventListenerO
 	return noop;
 }
 
-export function listen_swap(handler: EventListenerOrEventListenerObject|null|undefined|false, factory: (handler:EventListenerOrEventListenerObject|null|undefined|false) => Function) {
+export function listen_and_update(get_handler: ()=>EventListenerOrEventListenerObject|null|undefined|false, factory: (handler:EventListenerOrEventListenerObject|null|undefined|false) => Function) {
-	let disposeHandle: Function = factory(handler);
+	let handler = get_handler();
+	let dispose_handle: Function = factory(handler);
 	const dispose = () => {
-		disposeHandle();
+		dispose_handle();
 	}
-	dispose.swap = (new_handler:EventListenerOrEventListenerObject) => {
+	// update :
+	dispose.p = () => {
+		const new_handler = get_handler();
 		if (new_handler !== handler) {
-			disposeHandle();
+			dispose_handle();
 			handler = new_handler;
-			disposeHandle = factory(handler);
+			dispose_handle = factory(handler);
 		}
 	}
 	return dispose;