Added py:all-done event (#1756)

pyscript.core/src/all-done.js

@@ -0,0 +1,62 @@
+import TYPES from "./types.js";
+import hooks from "./hooks.js";
+
+const DONE = "py:all-done";
+
+const {
+    onAfterRun,
+    onAfterRunAsync,
+    codeAfterRunWorker,
+    codeAfterRunWorkerAsync,
+} = hooks;
+
+const waitForIt = [];
+const codes = [];
+
+const codeFor = (element) => {
+    const isAsync = element.hasAttribute("async");
+    const { promise, resolve } = Promise.withResolvers();
+    const type = `${DONE}:${waitForIt.push(promise)}`;
+
+    // resolve each promise once notified
+    addEventListener(type, resolve, { once: true });
+
+    if (element.hasAttribute("worker")) {
+        const code = `
+            from pyscript import window as _w
+            _w.dispatchEvent(_w.Event.new("${type}"))
+        `;
+        if (isAsync) codeAfterRunWorkerAsync.add(code);
+        else codeAfterRunWorker.add(code);
+        return code;
+    }
+
+    // dispatch only once the ready element is the same
+    const code = (_, el) => {
+        if (el === element) dispatchEvent(new Event(type));
+    };
+
+    if (isAsync) onAfterRunAsync.add(code);
+    else onAfterRun.add(code);
+    return code;
+};
+
+const selector = [];
+for (const [TYPE] of TYPES)
+    selector.push(`script[type="${TYPE}"]`, `${TYPE}-script`);
+
+// loop over all known scripts and elements
+for (const element of document.querySelectorAll(selector.join(",")))
+    codes.push(codeFor(element));
+
+// wait for all the things then cleanup
+Promise.all(waitForIt).then(() => {
+    // cleanup unnecessary hooks
+    for (const code of codes) {
+        onAfterRun.delete(code);
+        onAfterRunAsync.delete(code);
+        codeAfterRunWorker.delete(code);
+        codeAfterRunWorkerAsync.delete(code);
+    }
+    dispatchEvent(new Event(DONE));
+});