Added storage download url pipe

docs/storage/storage.md

@@ -186,6 +186,16 @@ export class AppComponent {
 
 ### Downloading Files
 
+A convenient pipe exists for simple in page references.
+
+```ts
+@Component({
+  selector: 'app-root',
+  template: `<img [src]="'users/davideast.jpg' | ngfbStorageUrl | async" />`
+})
+export class AppComponent {}
+```
+
 To download a file you'll need to create a reference and call the `getDownloadURL()` method on an `AngularFireStorageReference`.
 
 ```ts

src/storage/pipes/storageUrl.pipe.ts

@@ -0,0 +1,13 @@
+import { Pipe } from '@angular/core';
+import { AngularFireStorage } from '../storage';
+
+/** to be used with in combination with | async */
+@Pipe({
+  name: 'ngfbStorageUrl'
+}) export class AngularFirestoreStorageUrl implements PipeTransform {
+  constructor(public storage: AngularFireStorage) {}
+
+  transform(path) {
+    return this.storage.ref(path).getDownloadURL();
+  }
+}

src/storage/storage.module.ts

@@ -1,7 +1,9 @@
 import { NgModule } from '@angular/core';
 import { AngularFireStorage } from './storage';
+import { AngularFirestoreStorageUrl } from './pipes/storageUrl.pipe';
 
 @NgModule({
+  declarations: [ AngularFirestoreStorageUrl ],
   providers: [ AngularFireStorage ]
 })
 export class AngularFireStorageModule { }

src/storage/storage.spec.ts

@@ -6,6 +6,7 @@ import { AngularFireStorage, AngularFireStorageModule, AngularFireUploadTask, BU
 import { COMMON_CONFIG } from '../test-config';
 import 'firebase/storage';
 import { rando } from '../firestore/utils.spec';
+import { AngularFirestoreStorageUrl } from './pipes/storageUrl.pipe';
 
 describe('AngularFireStorage', () => {
   let app: FirebaseApp;
@@ -135,6 +136,29 @@ describe('AngularFireStorage', () => {
 
   }
 
+  describe('pipes', () => {
+    it('ngfbStorageUrl should download a url', (done) => {
+      const data = { angular: 'fire' };
+      const blob = new Blob([JSON.stringify(data)], { type : 'application/json' });
+      const ref = afStorage.ref('af.json');
+      const task = ref.put(blob);
+      const ngfbStorageUrl = new AngularFirestoreStorageUrl( afStorage );
+
+      // Wait for the upload
+      task.then(() => {
+        ngfbStorageUrl.transform('af.json')
+        .subscribe(
+          url => {
+            expect(url).toBeDefined();
+            done();
+          },
+          done.fail
+        );
+      })
+      .catch( done.fail );
+    });
+  });
+
 });
 
 describe('AngularFireStorage w/options', () => {