firestore-database-utility

An utility class to access firestore database for Android (getOne, create, update, getMany).

FirestoreDbUtility.java is wrapper class to interact with firestore database in Android. Copy and paste this class along with all other helper classes and interface- FirestoreQueryConditionCode.java, FirestoreQuery.java, FirestoreDbOperationCallback.java in your android project.

Sample Usage-

First of all create an instance of FirestoreDbUtility in your ExampleActivity something like-

FirestoreDbUtility firestoreDbUtility = new FirestoreDbUtility();

Define collection name-

String collectionName = "users"; // collection (table) name

GET unique document from firestore collection

```
String documentName = "4PkPVt4jGnO5neiKTKbe9I8B9yz2"; // may be uid of FirebaseUser i.e. firebaseUser.getUid()

firestoreDbUtility.getOne(collectionName, documentName,
            new FirestoreDbOperationCallback() {
        @Override
        public void onSuccess(Object object) {
            DocumentSnapshot documentSnapshot = (DocumentSnapshot) object;
            User user = documentSnapshot.toObject(User.class); // User.java is a model class
            System.out.println(user.getEmail()); // do anything with your user object
        }

        @Override
        public void onFailure(Object object) {

        }
    });
```

CREATE a document in firestore collection or MERGE if document already exists

```
User user = new User(); // create an instance of User class and set relevant properties
user.setEmail('email@example.com');
user.setUid('4PkPVt4jGnO5neiKTKbe9I8B9yz2');
    
firestoreDbUtility.createOrMerge(collectionName,
              user.getUid(), user, new FirestoreDbOperationCallback() {
          @Override
          public void onSuccess(Object object) {
          }

          @Override
          public void onFailure(Object object) {
          }
      });
```

UPDATE a document in firestore collection

```
// set isOnline true of user
Map<String, Object> hashMap = new HashMap<>();
hashMap.put("online", true);

firestoreDbUtility.update(collectionName,
              firebaseUser.getUid(), hashMap, new FirestoreDbOperationCallback() {
          @Override
          public void onSuccess(Object object) {
          }

          @Override
          public void onFailure(Object object) {
          }
      });
```

QUERY or getMany documents from firestore collection

```
GeoPoint lesserGeoPoint = new GeoPoint(12.1, 77.1); // latitude is 12.1 and longitude is 77.1
GeoPoint greaterGeoPoint = new GeoPoint(13.0, 78);

List<FirestoreQuery> firestoreQueryList = new ArrayList<>();
firestoreQueryList.add(new FirestoreQuery(
        FirestoreQueryConditionCode.WHERE_LESS_THAN,
        "location",
        greaterGeoPoint
));
firestoreQueryList.add(new FirestoreQuery(
        FirestoreQueryConditionCode.WHERE_GREATER_THAN,
        "location",
        lesserGeoPoint
));

firestoreDbUtility.getMany(collectionName,
            firestoreQueryList, new FirestoreDbOperationCallback() {
        @Override
        public void onSuccess(Object object) {
            QuerySnapshot querySnapshot = (QuerySnapshot) object;
            for (DocumentSnapshot documentSnapshot: querySnapshot.getDocuments()) {
                User user = documentSnapshot.toObject(User.class); // do something with user object
            }
        }

        @Override
        public void onFailure(Object object) {
            showMessage("Failed to locate nearby travellers.");
        }
    });

```