[AAE-7010] - Fix nested linked dropdowns are not reset (#7463)

* [AAE-7010] - Fix nested linked dropdowns are not reset

* Rebase

* Reset rest in case value is not part of the options

* Update failing unit test due to form field changes

lib/core/form/components/widgets/core/form-field.model.spec.ts

@@ -531,7 +531,7 @@ describe('FormFieldModel', () => {
         expect(field.value).toBe(false);
     });
 
-    it('should update form with empty dropdown value', () => {
+    it('should delete empty dropdown value from the form values', () => {
         const form = new FormModel();
         const field = new FormFieldModel(form, {
             id: 'dropdown-1',
@@ -539,10 +539,10 @@ describe('FormFieldModel', () => {
         });
 
         field.value = 'empty';
-        expect(form.values['dropdown-1']).toEqual({});
+        expect(form.values['dropdown-1']).toBe(undefined);
 
         field.value = '';
-        expect(form.values['dropdown-1']).toEqual({});
+        expect(form.values['dropdown-1']).toBe(undefined);
     });
 
     it('should update form with dropdown value', () => {

lib/core/form/components/widgets/core/form-field.model.ts

@@ -293,17 +293,14 @@ export class FormFieldModel extends FormWidgetModel {
         if (json.type === FormFieldTypes.DROPDOWN) {
 
             if (json.options) {
-                const options = <FormFieldOption[]> json.options || [];
+                if (json.hasEmptyValue) {
-                if (options.length > 0) {
+                    const emptyOption = json.options[0];
-                    if (json.hasEmptyValue) {
+                    if (value === '' || value === emptyOption.id || value === emptyOption.name) {
-                        const emptyOption = json.options[0];
+                        value = emptyOption.id;
-                        if (value === '' || value === emptyOption.id || value === emptyOption.name) {
+                    }
-                            value = emptyOption.id;
+                } else {
-                        }
+                    if (value?.id && value?.name) {
-                    } else {
+                        value = value.id;
-                        if (value?.id && value?.name) {
-                            value = value.id;
-                        }
                     }
                 }
             }
@@ -371,7 +368,7 @@ export class FormFieldModel extends FormWidgetModel {
 
                 if (typeof this.value === 'string') {
                     if (this.value === 'empty' || this.value === '') {
-                        this.form.values[this.id] = {};
+                        delete this.form.values[this.id];
                         break;
                     }
 

lib/process-services-cloud/src/lib/form/components/widgets/dropdown/dropdown-cloud.widget.spec.ts

@@ -19,7 +19,7 @@ import { ComponentFixture, TestBed } from '@angular/core/testing';
 import { By } from '@angular/platform-browser';
 import { of, throwError } from 'rxjs';
 import { DropdownCloudWidgetComponent } from './dropdown-cloud.widget';
-import { FormFieldModel, FormModel, FormService, setupTestBed } from '@alfresco/adf-core';
+import { FormFieldModel, FormModel, FormService, setupTestBed, FormFieldEvent } from '@alfresco/adf-core';
 import { FormCloudService } from '../../../services/form-cloud.service';
 import { ProcessServiceCloudTestingModule } from '../../../../testing/process-service-cloud.testing.module';
 import { TranslateModule } from '@ngx-translate/core';
@@ -428,6 +428,25 @@ describe('DropdownCloudWidgetComponent', () => {
                 expect(widget.field.options.length).toBe(2);
                 expect(failedErrorMsgElement3).toBeNull();
             });
+
+            describe('Rest - On parent value changes (chain)', () => {
+                it('should fire a form field value changed event when the value gets reset (notify children on the chain to reset)', () => {
+                    spyOn(formCloudService, 'getRestWidgetData').and.returnValue(throwError('Failed to fetch options'));
+                    widget.field.options = mockConditionalEntries[1].options;
+                    widget.field.value = 'MI';
+                    fixture.detectChanges();
+
+                    const formFieldValueChangedSpy = spyOn(formService.formFieldValueChanged, 'next').and.callThrough();
+                    const formFieldValueChangedEvent = new FormFieldEvent(widget.field.form, widget.field);
+
+                    parentDropdown.value = 'GR';
+                    widget.selectionChangedForField(parentDropdown);
+                    fixture.detectChanges();
+
+                    expect(formFieldValueChangedSpy).toHaveBeenCalledWith(formFieldValueChangedEvent);
+                    expect(widget.field.options).toEqual([]);
+                });
+            });
         });
 
         describe('Manual options', () => {
@@ -480,6 +499,49 @@ describe('DropdownCloudWidgetComponent', () => {
                 expect(defaultOption.context.value).toBe('empty');
                 expect(defaultOption.context.viewValue).toBe('Choose one...');
             });
+
+            describe('Manual - On parent value changes (chain)', () => {
+                it('should reset the current value when it not part of the available options', () => {
+                    widget.field.options = mockConditionalEntries[1].options;
+                    widget.field.value = 'non-existent-value';
+                    fixture.detectChanges();
+
+                    parentDropdown.value = 'GR';
+                    widget.selectionChangedForField(parentDropdown);
+                    fixture.detectChanges();
+
+                    expect(widget.field.options).toEqual(mockConditionalEntries[0].options);
+                    expect(widget.fieldValue).toEqual('');
+                });
+
+                it('should not reset the current value when it is part of the available options', () => {
+                    widget.field.options = mockConditionalEntries[1].options;
+                    widget.field.value = 'ATH';
+                    fixture.detectChanges();
+
+                    parentDropdown.value = 'GR';
+                    widget.selectionChangedForField(parentDropdown);
+                    fixture.detectChanges();
+
+                    expect(widget.field.options).toEqual(mockConditionalEntries[0].options);
+                    expect(widget.fieldValue).toEqual('ATH');
+                });
+
+                it('should fire a form field value changed event when the value gets reset (notify children on the chain to reset)', () => {
+                    widget.field.options = mockConditionalEntries[1].options;
+                    widget.field.value = 'non-existent-value';
+                    fixture.detectChanges();
+
+                    const formFieldValueChangedSpy = spyOn(formService.formFieldValueChanged, 'next').and.callThrough();
+                    const formFieldValueChangedEvent = new FormFieldEvent(widget.field.form, widget.field);
+
+                    parentDropdown.value = 'GR';
+                    widget.selectionChangedForField(parentDropdown);
+                    fixture.detectChanges();
+
+                    expect(formFieldValueChangedSpy).toHaveBeenCalledWith(formFieldValueChangedEvent);
+                });
+            });
         });
 
         describe('Load selection for linked dropdown (i.e. saved, completed forms)', () => {

lib/process-services-cloud/src/lib/form/components/widgets/dropdown/dropdown-cloud.widget.ts

@@ -104,6 +104,7 @@ export class DropdownCloudWidgetComponent extends WidgetComponent implements OnI
                     this.field.options = result;
                     this.updateOptions();
                     this.field.updateForm();
+                    this.resetInvalidValue();
                 }, (err) => {
                     this.resetRestApiOptions();
                     this.handleError(err);
@@ -133,18 +134,18 @@ export class DropdownCloudWidgetComponent extends WidgetComponent implements OnI
     }
 
     private parentValueChanged(value: string) {
-        if (this.isValidValue(value)) {
+        if (value && !this.isDefaultValue(value)) {
             this.isValidRestType() ? this.persistFieldOptionsFromRestApi() : this.persistFieldOptionsFromManualList(value);
         } else if (this.isDefaultValue(value)) {
             this.resetRestApiErrorMessage();
             this.addDefaultOption();
+            this.resetInvalidValue();
+        } else {
+            this.field.options = [];
+            this.resetInvalidValue();
         }
     }
 
-    private isValidValue(value: string): boolean {
-        return !!value && value !== DropdownCloudWidgetComponent.DEFAULT_OPTION.id;
-    }
-
     private isDefaultValue(value: string): boolean {
         return value === DropdownCloudWidgetComponent.DEFAULT_OPTION.id;
     }
@@ -159,13 +160,37 @@ export class DropdownCloudWidgetComponent extends WidgetComponent implements OnI
             rulesEntries.forEach((ruleEntry: RuleEntry) => {
                 if (ruleEntry.key === value) {
                     this.field.options = ruleEntry.options;
-                    this.updateOptions();
+                    this.resetInvalidValue();
-                    this.field.updateForm();
                 }
             });
         }
     }
 
+    private resetInvalidValue() {
+        if (!this.isValidValue()) {
+            this.resetValue();
+        }
+    }
+
+    private resetValue() {
+        this.field.value = '';
+        this.selectionChangedForField(this.field);
+        this.updateOptions();
+        this.field.updateForm();
+    }
+
+    private isValidValue(): boolean {
+        return this.fieldValue && !this.isDefaultValue(this.fieldValue) && this.isSelectedValueInOptions();
+    }
+
+    private isSelectedValueInOptions(): boolean {
+        return [...this.field.options].map(option => option.id).includes(this.fieldValue);
+    }
+
+    get fieldValue(): string {
+        return this.field.value;
+    }
+
     private hasRuleEntries(): boolean {
         return !!this.field.rule.entries.length;
     }
@@ -269,10 +294,9 @@ export class DropdownCloudWidgetComponent extends WidgetComponent implements OnI
 
     resetRestApiOptions() {
         this.field.options = [];
+        this.resetValue();
         this.isRestApiFailed = true;
         this.restApiHostName = this.getRestUrlHostName();
-        this.updateOptions();
-        this.field.updateForm();
     }
 
     private getRestUrlHostName(): string {