fix(core): clear value on hide for array type (#2522)

fix #2480
ngx-formly · Sep 26, 2020 · 49b3775 · 49b3775
1 parent a8fe97d
commit 49b3775
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Showing 3 changed files with 17 additions and 8 deletions.
diff --git a/src/core/src/lib/components/formly.form.spec.ts b/src/core/src/lib/components/formly.form.spec.ts
@@ -151,6 +151,9 @@ describe('FormlyForm Component', () => {
       ];
 
       const { model, fields } = fixture.componentInstance;
+      fixture.detectChanges();
+      expect(model).toEqual({ foo: [null] });
+      expect(fields[0].fieldGroup.length).toEqual(1);
 
       fields[0].hide = true;
       fixture.detectChanges();

diff --git a/src/core/src/lib/extensions/field-expression/field-expression.ts b/src/core/src/lib/extensions/field-expression/field-expression.ts
@@ -4,6 +4,7 @@ import { evalExpression, evalStringExpression } from './utils';
 import { Observable, Subscription } from 'rxjs';
 import { FormlyExtension } from '../../services/formly.config';
 import { unregisterControl, registerControl, updateValidity } from '../field-form/utils';
+import { FormArray } from '@angular/forms';
 
 /** @experimental */
 export class FieldExpressionExtension implements FormlyExtension {
@@ -228,13 +229,17 @@ export class FieldExpressionExtension implements FormlyExtension {
         unregisterControl(field);
         if (resetOnHide && field['autoClear']) {
           field.formControl.reset({ value: undefined, disabled: field.formControl.disabled });
+          if (field.formControl instanceof FormArray) {
+            assignFieldValue(field, undefined);
+            field.fieldGroup.length = 0;
+          }
         }
       } else if (hide === false) {
         if (field['autoClear'] && field.parent && !isUndefined(field.defaultValue) && isUndefined(getFieldValue(field))) {
           assignFieldValue(field, field.defaultValue);
         }
         registerControl(field);
-        if (field.fieldArray && (field.fieldGroup || []).length !== (field.model || []).length) {
+        if (field['autoClear'] && field.fieldArray && (field.fieldGroup || []).length !== (field.model || []).length) {
           (<any> field.options)._buildForm(true);
         }
       }

diff --git a/src/core/src/lib/utils.ts b/src/core/src/lib/utils.ts
@@ -43,19 +43,20 @@ export function assignFieldValue(field: FormlyFieldConfigCache, value: any) {
     return;
   }
 
+  let root = field;
+  while (root.parent) {
+    root = root.parent;
+    paths = [...getKeyPath(root), ...paths];
+  }
+
   if (value === undefined && field['autoClear']) {
     const k = paths.pop();
-    const m = paths.reduce((model, path) => model[path] || {}, field.parent.model);
+    const m = paths.reduce((model, path) => model[path] || {}, root.model);
     delete m[k];
     return;
   }
 
-  while (field.parent) {
-    field = field.parent;
-    paths = [...getKeyPath(field), ...paths];
-  }
-
-  assignModelValue(field.model, paths, value);
+  assignModelValue(root.model, paths, value);
 }
 
 export function assignModelValue(model: any, paths: string[], value: any) {