So you just finished quick start of Firebase. Or maybe you just heard about Firebase. ThreeBase tries to answer all your initial-questions-still-in-mind about Firebase effeciently right under 3 minutes!

1. ThreeBase
Firebase in 3 minutes or less.
by Mayank Mohan Upadhyay
linkedin.com/in/mumayank

2. Topics covered:
Prerequisite: Firebase> docs> android> quickguide
1. What is Firebase?
2. Is Firebase for me?
3. Understanding data in Firebase
4. Saving and Retrieving data
5. Security options
6. Offline feature

3. What is Firebase?
Firebase is:
a cloud services provider and
backend as a service company
based in San Francisco, California
founded in 2011 by Andrew Lee and James Tamplin
launched with a realtime cloud database in April 2012.
Firebase's primary product is a realtime database which provides
an API that allows developers to store and
sync data across multiple clients.

4. What is Firebase… in simple terms, please?
OK, so Firebase is basically a simple online database that offers:
real-time data syncs
has offline capabilities
provides security measures

5. Is Firebase for me?
You should switched to Firebase if your app:
backend has basic database structure
requires no complex queries on database
requires an online database which can be synced across devices in real-time
requires simple communication with server on-the-go
requires a combination of quick real-time database setup + security
You may also switch a node of your app backend to Firebase if that part satisfies
any of the above criteria.

6. Understanding data in Firebase
All Firebase database data is stored as JSON objects.
{
"users": {
"friends": { "brinchen": true },
"name": "Mary Chen"
}
}

7. Saving Data
setValue( )
Write or replace data to a defined path, like messages/users/<username>
updateChildren( )
Update some of the keys for a defined path without replacing all of the data
push( )
Add to a list of data in your Firebase database. Every time you call push() Firebase generates a
unique ID, like messages/users/<unique-user-id>/<username>
runTransaction( )
Use our transactions feature when working with complex data that could be corrupted by

8. If you'd like to know when your data has been committed, you can add a completion
listener:
ref.setValue("I'm writing data", new Firebase.CompletionListener() {
@Override
public void onComplete(FirebaseError firebaseError, Firebase firebase) {
if (firebaseError != null) {
System.out.println("Data could not be saved. " + firebaseError.getMessage());
} else {
System.out.println("Data saved successfully.");
}
}
});

9. Reading Data
With Firebase queries, we can selectively retrieve data based on various factors. To
construct a query, you start by specifying how you want your data to be ordered
using one of the ordering functions:
orderByChild(), orderByKey(), orderByValue(), or orderByPriority().
You can then combine these with five other methods to conduct complex queries:
limitToFirst(), limitToLast(), startAt(), endAt(), and equalTo().

10. Security Options
Authentication
Valid user entry (password entry)
Authorization
Defining permissions of each user
Rules:
.read
.write
.validate

11. Offline feature
Firebase apps automatically handle temporary network interruptions for you.
Cached data will still be available while offline and your writes will be resent
when network connectivity is recovered. But if the app is restarted, unsent data
will be lost.
Enabling disk persistence allows our app to also keep all of its state even after an
app restart. We can enable disk persistence with just one line of code.
Firebase.getDefaultConfig().setPersistenceEnabled(true);
With disk persistence enabled, our synced data and writes will be persisted to disk
across app restarts and our app should work seamlessly in offline situations.

12. Offline feature
Firebase synchronizes and stores a local copy of the data for active listeners. In
addition, you can keep specific locations in sync.
scoresRef.keepSynced(true);
The client will automatically download the data at these locations and keep it in
sync even if the reference has no active listeners. You can turn synchronization
back off with the following line of code.
scoresRef.keepSynced(false);
By default, 10MB of previously synced data will be cached. This should be enough
for most applications. If the cache outgrows its configured size, Firebase will
purge data that has been used least recently. Data that is kept in sync, will not

13. Thank You!
Questions are welcomed, Feedback is appreciated!