CODEWITHSUNDEEP
javaandroidjsonfirebasegoogle-cloud-firestore
Slaknation
Slaknation

Reputation: 1926

Android Firebase Firestore: Get data from deep in Firestore document

I have a firestore database document that essentially looks like this:

{
    "name": "George",
    "weeks": [
        {
            "checked": true,
            "days": [
                {
                    "checked": true,
                    "exercises": [
                        {
                            "exercise": "Bench Press",
                            "sets": [
                                {
                                    "weight": 300,
                                    "reps": 20
                                },
                                {
                                    "weight": 400,
                                    "reps": 30
                                }
                            ]
                        }
                    ]
                }
            ]
        }
    ]
}

I know I can get the data for the document by doing:

FirebaseFirestore db = FirebaseFirestore.getInstance();
CollectionReference userRef = db.collection("users");
Query usersDataQuery = userRef.whereEqualTo("name", "George");

    usersDataQuery.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
        @Override
        public void onComplete(@NonNull Task<QuerySnapshot> task) {
            if (task.isSuccessful()){
                for(QueryDocumentSnapshot document: task.getResult()){
                    Log.d("data = ", document.getId() + " => " + document.getData());
                }
            }
        }
    });

but then document .getData() comes back as:

2 => {weeks=[{days=[{exercises=[{sets=[{weight=300, reps=20}, {weight=400, reps=30}, {weight=500, reps=40}], exercise=Bench Press}, {sets=[{weight=300, reps=20}, {weight=400, reps=30}, {weight=500, reps=40}], exercise=Skull Crushers}, {sets=[{weight=300, reps=20}, {weight=400, reps=30}, {weight=500, reps=40}], exercise=Flyes}, {sets=[{weight=600, reps=20}, {weight=900, reps=30}, {weight=780, reps=40}], exercise=Incline Bench Press}], checked=true}], checked=true}], name=George}

And I have no way of getting to the weight in the first index of "sets". You would think you could do something like: document.getData()["weeks"][0]["days"][0]["exercises"][0]["sets"][0]["weight"] But I have not found a way to do it like this. Let me know if there is a good solution to getting data like that.

Upvotes: 1

Views: 957

Answers (1)

Doug Stevenson
Doug Stevenson

Reputation: 317467

As you can see from the API documentation, getData() returns a Map of all the fields and their values in the document. You need to dive into these values.

Also note that each field value in a document will surface as an appropriate Java type that describes each value. So, if a field contains an object, the field value type will be a Map<String,Object> whose keys and values are going to be the properties and values of that object. If a field value contains an array, You'll get a List<Object> that contains each value of the array.

Since you have a lot of nested lists and object, you will end up writing a lot of code that unpacks each of these lists and maps to discover your data. You might end up doing a lot of debug logging to learn how to do this effectively.

Upvotes: 1

Related Questions