Food Delivery App 9 - Firebase CRUD Operations with AngularFire Library

 

 

  

Firebase CRUD operations for Object

Create an object binding/ Retrieve

item: AngularFireObject<any>; // db: AngularFireDatabase this.item = db.object('item');   // or Observable<any> item = db.object('item').valueChanges();

Create

// db: AngularFireDatabase const itemRef = db.object('item');   // set() for destructive updates itemRef.set({ name: 'grokonez'});

Update

// db: AngularFireDatabase const itemRef = db.object('item'); itemRef.update({ url: 'grokonez.com'});

Delete

// db: AngularFireDatabase const itemRef = db.object('item'); itemRef.remove();

List of Objects

Create a list binding/ Retrieve

– Returns an Observable of data as a synchronized array of JSON objects without snapshot metadata. It is simple to render to a view:

items: Observable<any[]>; // db: AngularFireDatabase this.items = db.list('items').valueChanges();

– Returns an Observable of data as a synchronized array of AngularFireAction<DatabaseSnapshot>[] with metadata (the underyling DatabaseReference and snapshot key):

items: Observable<any[]>; // db: AngularFireDatabase this.items = db.list('items').snapshotChanges();

Create

// db: AngularFireDatabase const itemsRef = db.list('items'); itemsRef.push({ site: 'grokonez.com' });

Update

// set(): destructive update // delete everything currently in place, then save the new value const itemsRef = db.list('items'); // db: AngularFireDatabase itemsRef.set('key', { url: 'jsa.com' });   // update(): non-destructive update // only updates the values specified const itemsRef = db.list('items'); // db: AngularFireDatabase itemsRef.update('key', { url: 'javasampleapp.com' });

Delete

// db: AngularFireDatabase const itemsRef = db.list('items'); itemsRef.remove('key');   // delete entire list itemsRef.remove();