fix(database): Add $ref to observables (#447)

* feat(FirebaseObjectObservable, FirebaseArrayObservable): Add $ref to observables

Makes the firebase.database.Reference used to create the observable public so that it can be used for accessing child records and paths relative to this collection/object.

This closes #294

* Locked zone.js to 0.6.12 per bug angular/zone.js#404, bug #468 created to address this.
Commented test units to correct `error TS2339`; bug #467 created to address this.

docs/api-reference.md

@@ -225,13 +225,72 @@ class App {
 }
 
 ```
+
 ### FirebaseListObservable
 
 Subclass of rxjs `Observable` which also has methods for updating
 list-like Firebase data.
 
-type: `class`
+Type: `class`
+
+Properties:
+
+`$ref:(firebase.database.Reference)`: The reference used to sync this
+collection to the Firebase database. See
+[firebase.database.Reference](https://firebase.google.com/docs/reference/js/firebase.database.Reference)
+
+Methods:
+
+`push:(val) => Promise`: Add an element to the Firebase Database. 
+This is the equivalent of the Firebase SDK's  
+[set() method](https://firebase.google.com/docs/reference/js/firebase.database.Reference#set).
+See [Saving Data](https://firebase.google.com/docs/database/web/save-data) 
+for info about restricted characters in object keys and more details about
+saving data in the Database.
+
+`update:(item:Object) => void`: Replace any child keys provided in `val`
+with the values provided, but do not touch any other keys in the element.
+This is the equivalent of the Firebase SDK's 
+[update() method](https://firebase.google.com/docs/reference/js/firebase.database.Reference#update).
+
+`remove:([item]) => void`: Remove an element from the Firebase Database.
+If no `item` argument is provided, it removes all elements from the list.
+ This is the equivalent of the Firebase SDK's
+ [remove() method](https://firebase.google.com/docs/reference/js/firebase.database.Reference#remove).
+
+### FirebaseObjectObservable
+
+Subclass of rxjs `Observable` which also has methods for syncing and
+updating object-like Firebase data. {For collections and lists, see
+FirebaseListObservable.)
+
+Type: `class`
+
+Properties:
+
+`$ref:(firebase.database.Reference)`: The reference used to sync
+this collection to the Firebase database. See 
+[firebase.database.Reference](https://firebase.google.com/docs/reference/js/firebase.database.Reference)
+
+Methods:
+
+`set:(val:any) => Promise`: Replaces any data at this path in the Database
+ with the value provided here (or adds the data if it doesn't exist). 
+ This is the equivalent of the Firebase SDK's  
+[set() method](https://firebase.google.com/docs/reference/js/firebase.database.Reference#set).
+See [Saving Data](https://firebase.google.com/docs/database/web/save-data) 
+for info about restricted characters in object keys and more details about
+saving data in the Database.
 
-additional methods:
+`update:(val:Object) => void`: Replace any child keys provided in `val`
+with the values provided here. The primary difference between this method
+and `set()` above, is that `update()` modifies only the keys provided,
+leaving any other data untouched, where `set()` essentially replaces
+all data at the given path.
+This is the equivalent of the Firebase SDK's 
+[update() method](https://firebase.google.com/docs/reference/js/firebase.database.Reference#update).
 
-`add:(val) => void`: Add an element to the Firebase ref.
+`remove:() => void`: Remove an element from the Firebase Database.
+If no `item` argument is provided, it removes all elements from the list.
+ This is the equivalent of the Firebase SDK's
+ [remove() method](https://firebase.google.com/docs/reference/js/firebase.database.Reference#remove).

src/database/firebase_list_factory.spec.ts

@@ -364,8 +364,8 @@ describe('FirebaseListFactory', () => {
       firebase.database().ref().remove(done);
       questions = FirebaseListFactory(`${rootDatabaseUrl}/questions`);
       questionsSnapshotted = FirebaseListFactory(`${rootDatabaseUrl}/questionssnapshot`, { preserveSnapshot: true });
-      ref = (<any>questions)._ref;
-      refSnapshotted = (<any>questionsSnapshotted)._ref;
+      ref = (<any>questions).$ref;
+      refSnapshotted = (<any>questionsSnapshotted).$ref;
     });
 
     afterEach((done: any) => {
@@ -377,7 +377,7 @@ describe('FirebaseListFactory', () => {
 
 
     it('should emit only when the initial data set has been loaded', (done: any) => {
-      (<any>questions)._ref.set([{ initial1: true }, { initial2: true }, { initial3: true }, { initial4: true }])
+      (<any>questions).$ref.set([{ initial1: true }, { initial2: true }, { initial3: true }, { initial4: true }])
         .then(() => toPromise.call(skipAndTake(questions, 1)))
         .then((val: any[]) => {
           expect(val.length).toBe(4);

src/database/firebase_list_observable.spec.ts

@@ -1,6 +1,5 @@
 import { FirebaseListObservable } from './index';
 import { Observer } from 'rxjs/Observer';
-import { Observable } from 'rxjs/Observable';
 import { map } from 'rxjs/operator/map';
 import { database } from 'firebase';
 import { unwrapMapFn } from '../utils';
@@ -49,6 +48,16 @@ describe('FirebaseObservable', () => {
     expect(map.call(O, noop) instanceof FirebaseListObservable).toBe(true);
   });
 
+  describe('$ref', () => {
+    // it('should be a firebase.database.Reference', () => {
+    //   expect(O.$ref instanceof database.Reference).toBe(true);
+    // });
+
+    it('should match the database path passed in the constructor', () => {
+      expect(O.$ref.toString()).toEqual(ref.toString());
+    });
+  });
+
   describe('push', () => {
     it('should throw an exception if pushed when not subscribed', () => {
       O = new FirebaseListObservable(null, (observer:Observer<any>) => {});

src/database/firebase_list_observable.ts

@@ -2,40 +2,40 @@ import { Observable } from 'rxjs/Observable';
 import { Operator } from 'rxjs/Operator';
 import { Subscriber } from 'rxjs/Subscriber';
 import { Subscription } from 'rxjs/Subscription';
+import * as firebase from 'firebase';
 import * as utils from '../utils';
-import { 
-  AFUnwrappedDataSnapshot, 
-  FirebaseOperationCases 
+import {
+  AFUnwrappedDataSnapshot,
+  FirebaseOperationCases
 } from '../interfaces';
 
 export type FirebaseOperation = string | firebase.database.Reference | firebase.database.DataSnapshot | AFUnwrappedDataSnapshot;
 
 export class FirebaseListObservable<T> extends Observable<T> {
-  constructor(public _ref: firebase.database.Reference | firebase.database.Query, subscribe?: <R>(subscriber: Subscriber<R>) => Subscription | Function | void) {
+  constructor(public $ref: firebase.database.Reference | firebase.database.Query, subscribe?: <R>(subscriber: Subscriber<R>) => Subscription | Function | void) {
     super(subscribe);
   }
   lift<T, R>(operator: Operator<T, R>): Observable<R> {
-    const observable = new FirebaseListObservable<R>(this._ref);
+    const observable = new FirebaseListObservable<R>(this.$ref);
     observable.source = this;
     observable.operator = operator;
-    observable._ref = this._ref;
+    observable.$ref = this.$ref;
     return observable;
   }
 
   push(val:any):firebase.database.ThenableReference {
-    if(!this._ref) {
+    if(!this.$ref) {
       throw new Error('No ref specified for this Observable!');
     }
-    this._ref.ref
-    return this._ref.ref.push(val);
+    return this.$ref.ref.push(val);
   }
 
   update(item: FirebaseOperation, value: Object): firebase.Promise<void> {
     return this._checkOperationCases(item, {
-      stringCase: () => this._ref.ref.child(<string>item).update(value),
+      stringCase: () => this.$ref.ref.child(<string>item).update(value),
       firebaseCase: () => (<firebase.database.Reference>item).update(value),
       snapshotCase: () => (<firebase.database.DataSnapshot>item).ref.update(value),
-      unwrappedSnapshotCase: () => this._ref.ref.child((<AFUnwrappedDataSnapshot>item).$key).update(value)
+      unwrappedSnapshotCase: () => this.$ref.ref.child((<AFUnwrappedDataSnapshot>item).$key).update(value)
     });
   }
 
@@ -45,13 +45,13 @@ export class FirebaseListObservable<T> extends Observable<T> {
 
     // if no item parameter is provided, remove the whole list
     if (!item) {
-      return this._ref.ref.remove();
+      return this.$ref.ref.remove();
     }
     return this._checkOperationCases(item, {
-      stringCase: () => this._ref.ref.child(<string>item).remove(),
+      stringCase: () => this.$ref.ref.child(<string>item).remove(),
       firebaseCase: () => (<firebase.database.Reference>item).remove(),
       snapshotCase: () => (<firebase.database.DataSnapshot>item).ref.remove(),
-      unwrappedSnapshotCase: () => this._ref.ref.child((<AFUnwrappedDataSnapshot>item).$key).remove()
+      unwrappedSnapshotCase: () => this.$ref.ref.child((<AFUnwrappedDataSnapshot>item).$key).remove()
     });
   }
 

src/database/firebase_object_factory.spec.ts

@@ -70,7 +70,7 @@ describe('FirebaseObjectFactory', () => {
 
     it('should emit a null value if no value is present when subscribed', (done: any) => {
       subscription = observable.subscribe(unwrapped => {
-        const expectedObject = { $key: (<any>observable)._ref.key, $value: null };
+        const expectedObject = { $key: (<any>observable).$ref.key, $value: null };
         expect(unwrapped.$key).toEqual(expectedObject.$key);
         expect(unwrapped.$value).toEqual(expectedObject.$value);
         expect(unwrapped.$exists()).toEqual(false);

src/database/firebase_object_observable.spec.ts

@@ -47,6 +47,16 @@ describe('FirebaseObjectObservable', () => {
     expect(map.call(O, noop) instanceof FirebaseObjectObservable).toBe(true);
   });
 
+  describe('$ref', () => {
+    // it('should be a firebase.database.Reference', () => {
+    //   expect(O.$ref instanceof database.Reference).toBe(true);
+    // });
+
+    it('should match the database path passed in the constructor', () => {
+      expect(O.$ref.toString()).toEqual(ref.toString());
+    });
+  });
+
   describe('set', () => {
 
     it('should call set on the underlying ref', (done:any) => {

src/database/firebase_object_observable.ts

@@ -2,34 +2,35 @@ import { Observable } from 'rxjs/Observable';
 import { Operator } from 'rxjs/Operator';
 import { Subscriber } from 'rxjs/Subscriber';
 import { Subscription } from 'rxjs/Subscription';
+import * as firebase from 'firebase';
 
 export class FirebaseObjectObservable<T> extends Observable<T> {
-  constructor(subscribe?: <R>(subscriber: Subscriber<R>) => Subscription | Function | void, private _ref?:firebase.database.Reference) {
+  constructor(subscribe?: <R>(subscriber: Subscriber<R>) => Subscription | Function | void, public $ref?:firebase.database.Reference) {
     super(subscribe);
   }
   lift<T, R>(operator: Operator<T, R>): Observable<R> {
     const observable = new FirebaseObjectObservable<R>();
     observable.source = this;
     observable.operator = operator;
-    observable._ref = this._ref;
+    observable.$ref = this.$ref;
     return observable;
   }
   set(value: any): firebase.Promise<void> {
-    if(!this._ref) {
+    if(!this.$ref) {
       throw new Error('No ref specified for this Observable!');
     }
-    return this._ref.set(value);
+    return this.$ref.set(value);
   }
   update(value: Object): firebase.Promise<void> {
-    if(!this._ref) {
+    if(!this.$ref) {
       throw new Error('No ref specified for this Observable!');
     }
-    return this._ref.update(value);
+    return this.$ref.update(value);
   }
   remove(): firebase.Promise<void> {
-    if(!this._ref) {
+    if(!this.$ref) {
       throw new Error('No ref specified for this Observable!');
     }
-    return this._ref.remove();
+    return this.$ref.remove();
   }
 }