Allow InputBinding.receiveMessage to be async

Author: wch

srcts/src/bindings/input/inputBinding.ts

@@ -44,7 +44,7 @@ class InputBinding {
   // 'data' should be an object with elements corresponding to value, min,
   // max, etc., as appropriate for the type of input object. It also should
   // trigger a change event.
-  receiveMessage(el: HTMLElement, data: unknown): void {
+  receiveMessage(el: HTMLElement, data: unknown): Promise<void> | void {
     throw "Not implemented";
     el; // unused var
     data; // unused var

srcts/src/shiny/shinyapp.ts

@@ -717,7 +717,7 @@ class ShinyApp {
 
     addMessageHandler(
       "inputMessages",
-      (message: Array<{ id: string; message: unknown }>) => {
+      async (message: Array<{ id: string; message: unknown }>) => {
         // inputMessages should be an array
         for (let i = 0; i < message.length; i++) {
           const $obj = $(".shiny-bound-input#" + $escape(message[i].id));
@@ -734,7 +734,7 @@ class ShinyApp {
             $(el).trigger(evt);
             if (!evt.isDefaultPrevented()) {
               try {
-                inputBinding.receiveMessage(el, evt.message);
+                await inputBinding.receiveMessage(el, evt.message);
               } catch (error) {
                 console.error(
                   "[shiny] Error in inputBinding.receiveMessage()",

srcts/types/src/bindings/input/inputBinding.d.ts

@@ -8,7 +8,7 @@ declare class InputBinding {
     getValue(el: HTMLElement): any;
     subscribe(el: HTMLElement, callback: (value: boolean) => void): void;
     unsubscribe(el: HTMLElement): void;
-    receiveMessage(el: HTMLElement, data: unknown): void;
+    receiveMessage(el: HTMLElement, data: unknown): Promise<void> | void;
     getState(el: HTMLElement): unknown;
     getRatePolicy(el: HTMLElement): {
         policy: RatePolicyModes;