added create-from functionality

src/app/process-page/form/process-parameters/parameter-value-input/file-value-input/file-value-input.component.html

@@ -0,0 +1,13 @@
+<label for="file-upload-{{index}}" class="d-flex align-items-center m-0">
+    <span class="btn btn-light">
+        {{'process.new.parameter.file.upload-button' | translate}}
+    </span>
+    <span class="file-name ml-1">{{fileObject?.name}}</span>
+</label>
+<input requireFile #file="ngModel" type="file" name="file-upload-{{index}}" id="file-upload-{{index}}" class="form-control-file d-none" [ngModel]="fileObject" (ngModelChange)="setFile($event)"/>
+<div *ngIf="file.invalid && (file.dirty || file.touched)"
+     class="alert alert-danger validation-error">
+    <div *ngIf="file.errors.required">
+        {{'process.new.parameter.file.required' | translate}}
+    </div>
+</div>

src/app/process-page/form/process-parameters/parameter-value-input/file-value-input/file-value-input.component.scss

@@ -0,0 +1,6 @@
+.file-name {
+    flex: 1;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}

src/app/process-page/form/process-parameters/parameter-value-input/file-value-input/file-value-input.component.spec.ts

@@ -0,0 +1,57 @@
+import { async, ComponentFixture, fakeAsync, TestBed, tick } from '@angular/core/testing';
+
+import { FormsModule, NgForm, ReactiveFormsModule } from '@angular/forms';
+import { TranslateLoader, TranslateModule } from '@ngx-translate/core';
+import { By } from '@angular/platform-browser';
+import { FileValueInputComponent } from './file-value-input.component';
+import { NO_ERRORS_SCHEMA } from '@angular/core';
+import { FileValueAccessorDirective } from '../../../../../shared/utils/file-value-accessor.directive';
+import { FileValidator } from '../../../../../shared/utils/require-file.validator';
+import { TranslateLoaderMock } from '../../../../../shared/mocks/translate-loader.mock';
+
+describe('FileValueInputComponent', () => {
+  let component: FileValueInputComponent;
+  let fixture: ComponentFixture<FileValueInputComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      imports: [
+        FormsModule,
+        TranslateModule.forRoot({
+          loader: {
+            provide: TranslateLoader,
+            useClass: TranslateLoaderMock
+          }
+        })],
+      declarations: [FileValueInputComponent, FileValueAccessorDirective, FileValidator],
+      schemas: [NO_ERRORS_SCHEMA]
+
+    })
+      .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(FileValueInputComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+
+  it('should not show a validation error if the input field was left untouched but left empty', () => {
+    const validationError = fixture.debugElement.query(By.css('.validation-error'));
+    expect(validationError).toBeFalsy();
+  });
+
+  it('should show a validation error if the input field was touched but left empty',  () => {
+    const input = fixture.debugElement.query(By.css('input'));
+    input.triggerEventHandler('blur', null);
+
+    fixture.detectChanges();
+
+    const validationError = fixture.debugElement.query(By.css('.validation-error'));
+    expect(validationError).toBeTruthy();
+  });
+});

src/app/process-page/form/process-parameters/parameter-value-input/file-value-input/file-value-input.component.ts

@@ -0,0 +1,26 @@
+import { Component, Optional } from '@angular/core';
+import { ValueInputComponent } from '../value-input.component';
+import { ControlContainer, NgForm } from '@angular/forms';
+import { controlContainerFactory } from '../../../process-form.component';
+
+/**
+ * Represents the user inputted value of a file parameter
+ */
+@Component({
+  selector: 'ds-file-value-input',
+  templateUrl: './file-value-input.component.html',
+  styleUrls: ['./file-value-input.component.scss'],
+  viewProviders: [ { provide: ControlContainer,
+    useFactory: controlContainerFactory,
+    deps: [[new Optional(), NgForm]] } ]
+})
+export class FileValueInputComponent extends ValueInputComponent<File> {
+  /**
+   * The current value of the file
+   */
+  fileObject: File;
+  setFile(files) {
+    this.fileObject = files.length > 0 ? files[0] : undefined;
+    this.updateValue.emit(this.fileObject);
+  }
+}