Add onFormieValidateError JS event for client-side error handling

Author: engram-design

src/web/assets/frontend/dist/js/formie.js

@@ -251,6 +251,13 @@ export class FormieFormBase {
         return this.$form.dispatchEvent(validateEvent);
     }
 
+    validateError(data = {}) {
+        this.$form.dispatchEvent(new CustomEvent('onFormieValidateError', {
+            bubbles: true,
+            detail: data,
+        }));
+    }
+
     afterValidate() {
         // Create an event for after validation. This is mostly for third-parties.
         const afterValidateEvent = this.eventObject('onAfterFormieValidate', {

src/web/assets/frontend/src/js/formie-form-base.js

@@ -266,6 +266,13 @@ export class FormieFormTheme {
             this.removeFormAlert();
         }
 
+        // Raise a client-side event for failed errors. Set a tiny delay to ensure the event fires correctly-timed
+        if (errors.length) {
+            setTimeout(() => {
+                this.form.validateError({ errors });
+            }, 10);
+        }
+
         return !errors.length;
     }