feat(form) : support promise for validate method #1857

src/components/form/form.vue

@@ -57,6 +57,7 @@
                 });
             },
             validate(callback) {
+                return new Promise(resolve => {
                     let valid = true;
                     let count = 0;
                     this.fields.forEach(field => {
@@ -64,11 +65,16 @@
                             if (errors) {
                                 valid = false;
                             }
-                        if (typeof callback === 'function' && ++count === this.fields.length) {
+                            if (++count === this.fields.length) {
+                                // all finish
+                                resolve(valid)
+                                if (typeof callback === 'function') {
                                     callback(valid);
                                 }
+                            }
                         });
                     });
+                })
             },
             validateField(prop, cb) {
                 const field = this.fields.filter(field => field.prop === prop)[0];