User Profile Sample: Couchbase Lite Fundamentals

Open the DatabaseManager.java file and locate the initCouchbaseLite method.

public void initCouchbaseLite(Context context) {
    CouchbaseLite.init(context);
}

Open the DatabaseManager.java file and locate the openOrCreateDatabaseForUser method.

public void openOrCreateDatabaseForUser(Context context, String username)

We create an instance of the DatabaseConfiguration within DatabaseManager.java via an abstract requirement from the parent class, BaseRepository. This is an optional step. In our case, we would like to override the default path of the database. Every user has their own instance of the Database that is located in a folder corresponding to the user. Please note that the default path is platform specific.

DatabaseConfiguration config = new DatabaseConfiguration();
config.setDirectory(String.format("%s/%s", context.getFilesDir(), username));

Then we create a local Couchbase Lite database named "userprofiles" for the user. If a database already exists for the user, the existing version is returned.

Open the DatabaseManager.java file and locate the registerForDatabaseChanges() function.

We register a change listener with the database. This is an optional step. We track the ListenerToken as it is needed for removing the listener.

// Add database change listener
listenerToken = database.addChangeListener(new DatabaseChangeListener() {
    @Override
    public void changed(final DatabaseChange change) {
        if (change != null) {
            for(String docId : change.getDocumentIDs()) {
                Document doc = database.getDocument(docId);
                if (doc != null) {
                    Log.i("DatabaseChangeEvent", "Document was added/updated");
                }
                else {

                    Log.i("DatabaseChangeEvent","Document was deleted");
                }
            }
        }
    }
});

Open the DatabaseManager.java file and locate the closeDatabaseForCurrentUser() function.

public void closeDatabaseForUser()

Closing the database is pretty straightforward

database.close();

Open the DatabaseManager.java file and locate the deregisterForDatabaseChanges() function.

private void deregisterForDatabaseChanges()

We stop listening to database changes by passing in the ListenerToken associated with the listener.

database.removeChangeListener(listenerToken);

Open the DatabaseManager.java file and locate the getCurrentUserDocId method. This document Id is constructed by prefixing the term "user::" to the email Id of the user.

public String getCurrentUserDocId() {
    return "user::" + currentUser;
}

Next, in the UserProfilePresenter.java file, locate the fetchProfile method.

public void fetchProfile()

We try to fetch the Document with specified userProfileDocId from the database.

String docId = DatabaseManager.getSharedInstance().getCurrentUserDocId();

if (database != null) {

    Map<String, Object> profile = new HashMap<>(); (1)

    profile.put("email", DatabaseManager.getSharedInstance().currentUser); (2)

    Document document = database.getDocument(docId); (3)

    if (document != null) {
        profile.put("name", document.getString("name")); (4)
        profile.put("address", document.getString("address")); (4)
        profile.put("imageData", document.getBlob("imageData")); (4)
    }

    mUserProfileView.showProfile(profile); (5)
}

Open the UserProfilePresenter.java file and locate the saveProfile method.

public void saveProfile(Map<String,Object> profile)

We create a mutable instance of the Document. By default, all APIs in Couchbase Lite deal with immutable objects, thereby making them thread-safe by design. In order to mutate an object, you must explicitly get a mutable copy of the object. Use appropriate type-setters to set the various properties of the Document.

MutableDocument mutableDocument = new MutableDocument(docId, profile);

Save the document.

database.save(mutableDocument);

You should have followed the steps discussed in the "Try It Out" section under Create and Open a Database.

Enter a "name" for the user in the Text Entry box and Tap "Save".

Confirm that you see a "Successfully Updated Profile" toast message. The first time you update the profile screen, the Document will be created.

Now tap on the "Upload Photo" button and select an image from the Photo Album.

Tap "Save"

Confirm that you see the toast message "Successfully Updated Profile". The Document will be updated this time.

Tap "Log Out" and log out of the app

Log back into the app with the same user credentials you used earlier. In my example, I used "demo@example.com" and "password".

Confirm that you see the profile screen with the name and image values that you set earlier.