How to get size for Firestore POSTID Collection in Android?

Question

See the code:

private void initFirebase() {
        try {
            for (int i = 1; i < 16; i++) {
                mDatabase.collection(POST_ID).document("1").collection(PREVIEW)
                        .get()
                        .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                            @Override
                            public void onComplete(@NonNull Task<QuerySnapshot> task) {
                                if (task.isSuccessful()) {
                                    for (QueryDocumentSnapshot document : task.getResult()) {
                                        postMap.putAll(document.getData());
                                    }
                                    if (postMap != null) {
                                        Post post = new Post();
                                        post.setTitle(Objects.requireNonNull(postMap.get(POST_NAME)).toString());
                                        post.setDesc(Objects.requireNonNull(postMap.get(POST_DESC)).toString());
                                        post.setUrl(Objects.requireNonNull(postMap.get(POST_URL)).toString());
                                        postList.add(post);
                                    }

                                    setAdapter();
                                } else {
                                    showLog("Error getting documents: " + task.getException());
                                }
                            }
                        });
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

instead of for (int i = 1; i < 16; i++) { 16 I want the size which existed in my Firestore Collection. I tried all suggestion, but there is no mDatabase.collection(POST_ID).size()

DB Structure:

Firestore-root
     |
     --- PostId (collecton)
          |
          ---

I want the size of postId collection.

Why are you looping? You never used the variable `i` in the code. — OhhhThatVarun, May 18 '20 at 14:36
@OhhhThatVarun I'll loop 'i' here: mDatabase.collection(POST_ID).document("1") — , May 18 '20 at 14:38
You wanna do that because you need all the documents in the database? — OhhhThatVarun, May 18 '20 at 14:39
@OhhhThatVarun See my DB structure is different. I manually created that in console. so better you don't think that much. Just tell me how will I get the size? — , May 18 '20 at 14:45
@OhhhThatVarun That won't help, because after I , I have some more children/collection — , May 18 '20 at 14:54

OhhhThatVarun · Accepted Answer · 2020-05-18T15:01:50.603

0

For size

int count = 0;
db.collection("POST_ID")
    .get()
    .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
        @Override
        public void onComplete(@NonNull Task<QuerySnapshot> task) {
            if (task.isSuccessful()) {
               count = task.getResult().size();
            } else {
                Log.d(TAG, "Error getting documents: ", task.getException());
            }
        }
    });

private void initFirebase() {
        try {
            for (int i = 0; i < count; i++) {
                mDatabase.collection(POST_ID).document(i).collection(PREVIEW)
                        .get()
                        .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                            @Override
                            public void onComplete(@NonNull Task<QuerySnapshot> task) {
                                if (task.isSuccessful()) {
                                    for (QueryDocumentSnapshot document : task.getResult()) {
                                        postMap.putAll(document.getData());
                                    }
                                    if (postMap != null) {
                                        Post post = new Post();
                                        post.setTitle(Objects.requireNonNull(postMap.get(POST_NAME)).toString());
                                        post.setDesc(Objects.requireNonNull(postMap.get(POST_DESC)).toString());
                                        post.setUrl(Objects.requireNonNull(postMap.get(POST_URL)).toString());
                                        postList.add(post);
                                    }

                                    setAdapter();
                                } else {
                                    showLog("Error getting documents: " + task.getException());
                                }
                            }
                        });
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Then use this count variable as size.

edited May 18 '20 at 15:01

answered May 18 '20 at 14:43

OhhhThatVarun

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Arey yar, after mDatabase.collection(POST_ID).document("1"). this I have /preview/some other fields for every id – May 18 '20 at 14:53
please tell me about size – May 18 '20 at 14:53
@ShefaliSingh check update. – OhhhThatVarun May 18 '20 at 14:56
Arey baba, why you're not understanding, see: postId / here i / preview /.... – May 18 '20 at 15:00
that's why I want to loop – May 18 '20 at 15:00
@ShefaliSingh what about now? – OhhhThatVarun May 18 '20 at 15:02
let me chk, I think it'll work, but why there is no size(), why we have to loop around n all? – May 18 '20 at 15:04
Working, but bit lengthy process. Anyways Thank you so much. – May 18 '20 at 15:07
Can you help me this https://stackoverflow.com/questions/61857048/how-can-i-do-toleftof-for-two-ids-in-same-xml-layout-in-android – May 18 '20 at 15:08
@ShefaliSingh no problem. You might wanna move the `count` variable inside your function. – OhhhThatVarun May 18 '20 at 15:08
yupp I'll do it – May 18 '20 at 17:29

How to get size for Firestore POSTID Collection in Android?

1 Answers1