Firebase push() vs Angularfire $save()

问题

How does angularfire .$save() compare to firebase .push()? I know push() will generate a unique key when data is stored, but I can't recreate the behavior using angularfire. Is there a way or should I be using .push() and if so, in what case would you use $save()?

Here is one sample I have using $save()...

        var fb = new Firebase(FIREBASE_URI).child('Test');
        var article = $firebaseObject(fb);

        article.Foo = "bar";
        article.$save().then(function(fb) {
            console.log(fb.key() === article.$id); // true
        }, function(error) {
            console.log("Error:", error);
        });

And another using .push()...

        var article = new Firebase(FIREBASE_URI).child('Articles');

        article.push({
            title:   $scope.article.title,
            post:    $scope.article.post
        }, function(error) {
            if (error) {
                console.log("Error:", error);
            }
        });

What are the Pros/Cons and use cases for both?

回答1:

How push/$add and set/$save relate

AngularFire's $save() method is implemented using Firebase's set() method. Both save data to an existing/known location.

Firebase's push() operation corresponds to AngularFire's $add() method. Both will generate a new unique child key, which means you can use them to add new data at a location that is guaranteed to not conflict with any existing data.

When to use push and when to use set

While the above is a hard truth, this bit is more subjective. So don't blindly copy it, but figure out how it applies to your situation.

Typically you should be using set()/$save() if you either have an object that already exists in the database or if you are working with objects that have a natural key.

If the items don't have a natural key or you want them to be sorted "chronologically", you'll typically use push()/$add() to generate a key for you. This will ensure that the items are stored under a unique key and that newer items show up later in the list.

So if you're working with users, you'll typically store then under their uid using something like ref.child('users').child(user.uid).set(user). On the other hand, if you're adding chat message to a chat room, you'll use something like ref.child('chat').push({ name: 'Adam Youngers', 'Firebase push() vs Angularfire $save()' }).

来源：https://stackoverflow.com/questions/35954662/firebase-push-vs-angularfire-save

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