Added required input for single file attachment

src/app/public/modules/checkbox/checkbox.component.ts

@@ -10,11 +10,14 @@ import {
 } from '@angular/core';
 
 import {
-  AbstractControl,
   ControlValueAccessor,
   NgControl
 } from '@angular/forms';
 
+import {
+  SkyFormsUtility
+} from '../shared/forms-utility';
+
 /**
  * Monotonically increasing integer used to auto-generate unique ids for checkbox components.
  */
@@ -101,7 +104,7 @@ export class SkyCheckboxComponent implements ControlValueAccessor, OnInit {
    */
   @Input()
   set required(value: boolean) {
-    this._required = this.coerceBooleanProperty(value);
+    this._required = SkyFormsUtility.coerceBooleanProperty(value);
   }
 
   get required(): boolean {
@@ -127,7 +130,7 @@ export class SkyCheckboxComponent implements ControlValueAccessor, OnInit {
   public ngOnInit(): void {
     if (this.ngControl) {
       // Backwards compatibility support for anyone still using Validators.Required.
-      this.required = this.required || this.hasRequiredValidation(this.ngControl);
+      this.required = this.required || SkyFormsUtility.hasRequiredValidation(this.ngControl);
     }
   }
 
@@ -201,26 +204,4 @@ export class SkyCheckboxComponent implements ControlValueAccessor, OnInit {
     this.checked = !this.checked;
   }
 
-  /**
-   * Gets the required state of the checkbox.
-   * Currently, Angular doesn't offer a way to get this easily, so we have to create an empty
-   * control using the current validator to see if it throws a `required` validation error.
-   * https://github.com/angular/angular/issues/13461#issuecomment-340368046
-   */
-  private hasRequiredValidation(ngControl: NgControl): boolean {
-    const abstractControl = ngControl.control as AbstractControl;
-    if (abstractControl && abstractControl.validator) {
-      const validator = abstractControl.validator({} as AbstractControl);
-      if (validator && validator.required) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  /** Coerces a data-bound value (typically a string) to a boolean. */
-  private coerceBooleanProperty(value: any): boolean {
-    return value !== undefined && `${value}` !== 'false';
-  }
-
 }

src/app/public/modules/file-attachment/file-attachment.component.html

@@ -4,6 +4,7 @@
   <div
     class="sky-file-attachment-label-wrapper"
     [ngClass]="{ 'sky-control-label-required': required && hasLabelComponent }"
+    [attr.aria-required]="(required) ? true : null"
     [attr.id]="labelElementId"
   >
     <ng-container *ngTemplateOutlet="labelContent"
@@ -22,6 +23,7 @@
       tabindex="-1"
       type="file"
       [attr.accept]="acceptedTypes || null"
+      [attr.required]="(required) ? '' : null"
       (change)="fileChangeEvent($event)"
       #fileInput
     >

src/app/public/modules/file-attachment/file-attachment.component.spec.ts

@@ -59,6 +59,7 @@ describe('File attachment', () => {
     fileAttachmentInstance = fixture.componentInstance.fileAttachmentComponent;
   });
 
+  //#region helpers
   function getInputDebugEl(): DebugElement {
     return fixture.debugElement.query(By.css('input'));
   }
@@ -304,18 +305,55 @@ describe('File attachment', () => {
   }
   //#endregion
 
-  it('should allow the user to specify if the file is required', fakeAsync(() => {
+  it('should not have required class and aria-reqiured attribute when not required', fakeAsync(() => {
     fileAttachmentInstance.ngAfterViewInit();
     tick();
     fixture.detectChanges();
+    const labelWrapper = getLabelWrapper();
+    const input = getInputDebugEl();
+
+    expect(input.nativeElement.getAttribute('required')).toBeNull();
+    expect(labelWrapper.classList.contains('sky-control-label-required')).toBe(false);
+    expect(labelWrapper.getAttribute('aria-required')).toBeNull();
+  }));
 
-    let labelWrapper = getLabelWrapper();
+  it('should have appropriate classes when file is required', fakeAsync(() => {
+    fixture.componentInstance.required = true;
+    fileAttachmentInstance.ngAfterViewInit();
+    tick();
+    fixture.detectChanges();
+    const labelWrapper = getLabelWrapper();
+    const input = getInputDebugEl();
+
+    expect(input.nativeElement.getAttribute('required')).not.toBeNull();
+    expect(labelWrapper.classList.contains('sky-control-label-required')).toBe(true);
+    expect(labelWrapper.getAttribute('aria-required')).toBe('true');
+  }));
+
+  it('should have appropriate classes when file is required and initialized with file', fakeAsync(() => {
+    fixture.componentInstance.required = true;
+    const testFile = <SkyFileItem> {
+      file: {
+        name: 'myFile',
+        type: '',
+        size: 1
+      },
+      url: 'myFile'
+    };
+    fileAttachmentInstance.value = testFile;
+    fileAttachmentInstance.ngAfterViewInit();
+    tick();
+    fixture.detectChanges();
+    const labelWrapper = getLabelWrapper();
+    const input = getInputDebugEl();
 
-    expect(fileAttachmentInstance.required).toBe(true);
+    expect(input.nativeElement.getAttribute('required')).not.toBeNull();
     expect(labelWrapper.classList.contains('sky-control-label-required')).toBe(true);
+    expect(labelWrapper.getAttribute('aria-required')).toBe('true');
   }));
 
   it('should handle removing the label', fakeAsync(() => {
+    fixture.componentInstance.required = true;
     fileAttachmentInstance.ngAfterViewInit();
     fileAttachmentInstance.ngAfterContentInit();
     tick();

src/app/public/modules/file-attachment/file-attachment.component.ts

@@ -7,25 +7,27 @@ import {
   ContentChildren,
   ElementRef,
   EventEmitter,
-  forwardRef,
   Input,
   OnDestroy,
+  Optional,
   Output,
-  ViewChild,
-  QueryList
+  QueryList,
+  Self,
+  ViewChild
 } from '@angular/core';
 
 import {
-  ControlValueAccessor,
-  AbstractControl,
-  NG_VALUE_ACCESSOR,
-  NG_VALIDATORS
+  NgControl
 } from '@angular/forms';
 
 import {
   Subject
 } from 'rxjs';
 
+import {
+  SkyFormsUtility
+} from '../shared/forms-utility';
+
 import {
   SkyFileAttachmentChange
 } from './types/file-attachment-change';
@@ -50,31 +52,16 @@ import {
   SkyFileItemService
 } from './file-item.service';
 
-// tslint:disable:no-forward-ref no-use-before-declare
-const SKY_FILE_ATTACHMENT_VALUE_ACCESSOR = {
-  provide: NG_VALUE_ACCESSOR,
-  useExisting: forwardRef(() => SkyFileAttachmentComponent),
-  multi: true
-};
-
-const SKY_FILE_ATTACHMENT_VALIDATOR = {
-  provide: NG_VALIDATORS,
-  useExisting: forwardRef(() => SkyFileAttachmentComponent),
-  multi: true
-};
-
 let uniqueId = 0;
+
 @Component({
   selector: 'sky-file-attachment',
   templateUrl: './file-attachment.component.html',
   styleUrls: ['./file-attachment.component.scss'],
-  providers: [
-    SKY_FILE_ATTACHMENT_VALUE_ACCESSOR,
-    SKY_FILE_ATTACHMENT_VALIDATOR
-  ],
   changeDetection: ChangeDetectionStrategy.OnPush
 })
-export class SkyFileAttachmentComponent implements ControlValueAccessor, AfterViewInit, AfterContentInit, OnDestroy {
+export class SkyFileAttachmentComponent implements AfterViewInit, AfterContentInit, OnDestroy {
+
   @Input()
   public acceptedTypes: string;
 
@@ -105,6 +92,13 @@ export class SkyFileAttachmentComponent implements ControlValueAccessor, AfterVi
 
   public rejectedOver: boolean = false;
 
+  /**
+   * Indicates whether the input is required for form validation.
+   * When you set this property to `true`, the component adds `aria-required` and `required`
+   * attributes to the input element so that forms display an invalid state until the input element
+   * is complete. This property accepts a `boolean` value.
+   */
+  @Input()
   public required: boolean = false;
 
   public set value(value: SkyFileItem) {
@@ -130,17 +124,24 @@ export class SkyFileAttachmentComponent implements ControlValueAccessor, AfterVi
   @ContentChildren(SkyFileAttachmentLabelComponent)
   private labelComponents: QueryList<SkyFileAttachmentLabelComponent>;
 
-  private control: AbstractControl;
   private enterEventTarget: any;
+
   private fileAttachmentId = uniqueId++;
+
   private ngUnsubscribe = new Subject<void>();
+
   private _value: any;
 
   constructor(
     private changeDetector: ChangeDetectorRef,
     private fileAttachmentService: SkyFileAttachmentService,
-    private fileItemService: SkyFileItemService
-  ) { }
+    private fileItemService: SkyFileItemService,
+    @Self() @Optional() private ngControl: NgControl
+  ) {
+    if (this.ngControl) {
+      this.ngControl.valueAccessor = this;
+    }
+  }
 
   public ngAfterViewInit(): void {
     // This is needed to address a bug in Angular 7.
@@ -149,19 +150,16 @@ export class SkyFileAttachmentComponent implements ControlValueAccessor, AfterVi
     // Of note is the parent check which allows us to determine if the form is reactive.
     // Without this check there is a changed before checked error
     /* istanbul ignore else */
-    if (this.control) {
+    if (this.ngControl) {
       setTimeout(() => {
-        this.control.setValue(this.value, {
+        this.ngControl.control.setValue(this.value, {
           emitEvent: false
         });
-
-        // Set required to apply required state to label
-        if (this.control.errors && this.control.errors.required) {
-          this.required = true;
-        }
-
         this.changeDetector.markForCheck();
       });
+
+      // Backwards compatibility support for anyone still using Validators.Required.
+      this.required = this.required || SkyFormsUtility.hasRequiredValidation(this.ngControl);
     }
   }
 
@@ -286,14 +284,6 @@ export class SkyFileAttachmentComponent implements ControlValueAccessor, AfterVi
     this.changeDetector.markForCheck();
   }
 
-  public validate(control: AbstractControl): { [key: string]: any } {
-    if (!this.control) {
-      this.control = control;
-    }
-
-    return undefined;
-  }
-
   public emitClick(): void {
     this.fileClick.emit({
       file: this.value

src/app/public/modules/file-attachment/fixtures/file-attachment.component.fixture.html

@@ -4,6 +4,7 @@
 >
   <sky-file-attachment
     formControlName="attachment"
+    [required]="required"
   >
     <sky-file-attachment-label
       *ngIf="showLabel"

src/app/public/modules/file-attachment/fixtures/file-attachment.component.fixture.ts

@@ -1,24 +1,31 @@
 import {
   Component,
-  ViewChild,
-  OnInit
+  OnInit,
+  ViewChild
 } from '@angular/core';
 
+import {
+  FormBuilder,
+  FormControl,
+  FormGroup
+} from '@angular/forms';
+
 import {
   SkyFileAttachmentComponent
 } from '../file-attachment.component';
 
-import { FormGroup, FormControl, Validators, FormBuilder } from '@angular/forms';
-
 @Component({
   selector: 'file-attachment-test',
   templateUrl: './file-attachment.component.fixture.html'
 })
 export class FileAttachmentTestComponent implements OnInit {
+
   public attachment: FormControl;
 
   public fileForm: FormGroup;
 
+  public required: boolean = false;
+
   public showLabel: boolean = true;
 
   @ViewChild(SkyFileAttachmentComponent)
@@ -29,7 +36,7 @@ export class FileAttachmentTestComponent implements OnInit {
   ) { }
 
   public ngOnInit(): void {
-    this.attachment = new FormControl(undefined, Validators.required);
+    this.attachment = new FormControl(undefined);
     this.fileForm = this.formBuilder.group({
       attachment: this.attachment
     });

src/app/public/modules/shared/forms-utility.ts

@@ -0,0 +1,32 @@
+import {
+  AbstractControl,
+  NgControl
+} from '@angular/forms';
+
+// Need to add the following to classes which contain static methods.
+// See: https://github.com/ng-packagr/ng-packagr/issues/641
+// @dynamic
+export class SkyFormsUtility {
+
+  /** Coerces a data-bound value (typically a string) to a boolean. */
+  public static coerceBooleanProperty(value: any): boolean {
+    return value !== undefined && `${value}` !== 'false';
+  }
+
+  /**
+   * Gets the required state of the checkbox.
+   * Currently, Angular doesn't offer a way to get this easily, so we have to create an empty
+   * control using the current validator to see if it throws a `required` validation error.
+   * https://github.com/angular/angular/issues/13461#issuecomment-340368046
+   */
+  public static hasRequiredValidation(ngControl: NgControl): boolean {
+    const abstractControl = ngControl.control as AbstractControl;
+    if (abstractControl && abstractControl.validator) {
+      const validator = abstractControl.validator({} as AbstractControl);
+      if (validator && validator.required) {
+        return true;
+      }
+    }
+    return false;
+  }
+}