try-login: trigger input events on form fields

Following up on 2a9b68c.

Some pages have custom input validation that is triggered when input focus
changes, this change triggers those events.

Additionally, `try-login.js` could run before the page is ready, so a delay was
added to ensure the page is ready before filling the form.

Author: netoarmando

brozzler/browser.py

@@ -948,6 +948,10 @@ def try_login(self, username, password, timeout=300):
             .render(username=username, password=password)
         )
 
+        self.logger.info("trying to login")
+        time.sleep(1)  # allow time for any scripts to run
+        self._wait_for_idle(idle_time=2, timeout=4)
+
         self.websock_thread.got_page_load_event = None
         self.send_to_chrome(
             method="Runtime.evaluate",

brozzler/js-templates/try-login.js.j2

@@ -39,6 +39,12 @@ var __brzl_tryLogin = function() {
         if (usernameField && passwordField) {
             usernameField.value = {{username|json}};
             passwordField.value = {{password|json}};
+            // Trigger input and change events for username and password fields
+            for (const field of [usernameField, passwordField]) {
+              field.dispatchEvent(new Event("input",  { bubbles: true }));
+              field.dispatchEvent(new Event("change", { bubbles: true }));
+              field.blur();
+            }
             console.log('submitting username=' + usernameField.value
                         + ' password=*** to detected login form');
             try {