Dev eromano external viewer (#1636)

* add extensibility point to add a custom viewer

* documentation and tests

* add example in document list

ng2-components/ng2-alfresco-viewer/src/directives/extension-viewer.directive.spec.ts

@@ -0,0 +1,62 @@
+/*!
+ * @license
+ * Copyright 2016 Alfresco Software, Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { ElementRef } from '@angular/core';
+import { CoreModule } from 'ng2-alfresco-core';
+import { ExtensionViewerDirective } from './extension-viewer.directive';
+import { ViewerComponent } from '../components/viewer.component';
+import { getTestBed, TestBed, async } from '@angular/core/testing';
+import { Injector } from '@angular/core';
+
+export class MockElementRef extends ElementRef {
+
+}
+
+describe('ExtensionViewerComponent', () => {
+    let injector: Injector;
+    let extensionViewerDirective: ExtensionViewerDirective;
+    let viewerComponent: ViewerComponent;
+
+    beforeEach(async(() => {
+        TestBed.configureTestingModule({
+            imports: [CoreModule.forRoot()],
+            providers: [
+                ExtensionViewerDirective,
+                {provide: ElementRef, useClass: MockElementRef},
+                ViewerComponent
+            ]
+        });
+        injector = getTestBed();
+        extensionViewerDirective = injector.get(ExtensionViewerDirective);
+        viewerComponent = injector.get(ViewerComponent);
+        extensionViewerDirective.templateModel = {template: '', isVisible: false};
+    }));
+
+    it('is defined', () => {
+        expect(extensionViewerDirective).toBeDefined();
+    });
+
+    it('if the file in the viewer has an extension handled by this extension isVisible should be true', () => {
+        extensionViewerDirective.supportedExtensions = ['xls', 'sts'];
+        expect(extensionViewerDirective.isVisible('xls')).toBeTruthy();
+    });
+
+    it('if the file in the viewer not has an extension handled by this extension isVisible should be false', () => {
+        extensionViewerDirective.supportedExtensions = ['xls', 'sts'];
+        expect(extensionViewerDirective.isVisible('png')).not.toBeTruthy();
+    });
+});