FirebaseDatabase

The FirebaseDatabase item allows to read and write user-specific and public data from and to the Firebase Realtime Database. Data is synced across all clients in realtime, and remains available when your app goes offline. As soon as the user goes online again, the changes are synced up to the Firebase cloud backend. More...

Import Statement: import VPlayPlugins 1.0
Inherits:

PluginItem

Properties

Signals

Methods

Detailed Description

Structuring Data

Data inside your Firebase Realtime Database is stored as a JSON tree. Unlike a SQL database, there are no tables or records. Theoretically, the Firebase database allows nesting your data up to 32 levels deep. However, a best practice is to avoid nesting data where possible and create a data structure as flat as possible.

Here is a short example what a Firebase database looks like. It contains a public branch, with a news item, and a users branch, that contains a list of users. User objects have the properties username, age and motto.

Note: Check out the Firebase Plugin page for more examples!

 {
   "public" : {
     "news" : "Firebase Plugin is now live!"
   },
   "users" : {
     "<user-id>" : {
       "username" : "John Doe",
       "age" : 22,
       "motto" : "V-Play is awesome!"
     }
   }
 }

Before creating the data structure for your project, we recommend to read the guide in the Firebase documentation here.

Database Rules

The private features of the FirebaseDatabase item only work in combination with the FirebaseAuth item and an authorized user. The public values can be accessed also without authentication, depending on the database rules.

In order to restrict access of parts of your database to only registered users, adapt your Firebase database rules accordingly.

Refer to the following JSON for a possible set of rules. The users branch is limited to authorized users. Only users with a FirebaseAuth::userId that matches the one from the key may access the sub-keys and thus read the containing data. In contrast, the public branch is readable and writeable by everyone, also unauthenticated users.

 // These rules grant access to a node matching the authenticated
 // user's ID from the Firebase auth token
 // Additionally, they grant access to everyone for the "public" branch
 {
   "rules": {
     "users": {
       "$uid": {
         ".read": "$uid === auth.uid",
         ".write": "$uid === auth.uid"
       }
     },
     "public": {
       "$uid": {
         ".read": true,
         ".write": true
       }
     }
   }
 }

To learn more on Database Rules, we recommend to read up on the topic in the Firebase Docs.

Does this plugin restrict me to use the default database structure?

No. If you use the database rules and a database structure as provided in the examples, you can use the FirebaseDatabase::setUserValue and FirebaseDatabase::getUserValue convenience functions to store and retrieve user-specific values. This might not be enough for some applications. For example, think of an application where you have a chat that two users can see, but everyone else can't.

If you prefer to create a complex database structure completely on your own, you can do so. Use the FirebaseAuth::userId property to restrict any sub-key to one or several specific users. This is useful if you intend to implement features such as a chat or user groups. Again, to learn how to create complex database structures and rulesets, refer to the Firebase Documentation for rules and data structure.

Property Documentation

realtimeUserValueKeys : list<string>

A list of user-specific keys for which you want to receive real-time changes from the database. When you add a value to this list, the FirebaseDatabase::realtimeUserValueChanged signal will be fired whenever the value changes in the database.

If you don't want to receive updates for this key anymore, remove it from the list.

See also FirebaseDatabase::realtimeValueKeys and FirebaseDatabase::realtimeUserValueChanged.


realtimeValueKeys : list<string>

A list of keys for which you want to receive real-time changes from the database. When you add a value to this list, the FirebaseDatabase::realtimeValueChanged signal will be fired whenever the value changes in the database.

If you don't want to receive updates for this key anymore, remove it from the list.

See also FirebaseDatabase::realtimeUserValueKeys and FirebaseDatabase::realtimeValueChanged.


Signal Documentation

readCompleted(bool success, string key, variant value)

This signal is called after the getValue() request has finished.

The success parameter is true, if the value was successfully read from the database. If the value can't be read, it is false.

The key parameter contains the key of the value that was requested, and value contains the value.

Note: If a value can't be read from the database, check the log output for an error description.


realtimeUserValueChanged(bool success, string key, variant value)

This signal is called whenever a key is added to the FirebaseDatabase::realtimeUserValueKeys list or an observed value gets changed.

The key parameter contains the key of the value that was observed, and value contains the value.

}

See also FirebaseDatabase::realtimeUserValueKeys.


realtimeValueChanged(bool success, string message)

This signal is called whenever a key is added to the FirebaseDatabase::realtimeValueKeys list or an observed value gets changed.

The key parameter contains the key of the value that was observed, and value contains the value.

See also FirebaseDatabase::realtimeValueKeys.


writeCompleted(bool success, string message)

This signal is called after the setValue() request has finished.

The success parameter is true, if the value was successfully written to the database. Otherwise, it's false. In this case, the message parameter contains an error description.


Method Documentation

void addRealtimeUserValueKey(string key)

Adds a key to the FirebaseDatabase::realtimeUserValueKeys property. When you add a value to this list, the FirebaseDatabase::realtimeUserValueChanged signal will be fired whenever the value changes in the database.

See also FirebaseDatabase::realtimeUserValueKeys.


void addRealtimeValueKey(string key)

Adds a key to the FirebaseDatabase::realtimeValueKeys property. When you add a value to this list, the FirebaseDatabase::realtimeValueChanged signal will be fired whenever the value changes in the database.

See also FirebaseDatabase::realtimeValueKeys.


getUserValue(key)

Retrieves the corresponding value for the given key from the Firebase database for the specific user. Use the FirebaseDatabase::readCompleted handler to check the result.

In difference to FirebaseDatabase::setValue, this function prepends users/<userId> to the key, so it is accessed from the user-restricted branch. This function will only work, if you use a database structure similar to the one presented in the example.

Note: This function requires Firebase authentication! It will fail if the user is not logged in.

See also FirebaseDatabase::readCompleted.


getValue(key)

Retrieves the corresponding value for the given key from the Firebase database without authentication. Use the FirebaseDatabase::readCompleted handler to check the result.

See also FirebaseDatabase::readCompleted.


void removeRealtimeUserValueKey(string key)

Removes a key from the FirebaseDatabase::realtimeUserValueKeys property. When a key is removed from the list, its value is no longer observed and you won't be notified if the value changes in the database.

See also FirebaseDatabase::realtimeUserValueKeys.


void removeRealtimeValueKey(string key)

Removes a key from the FirebaseDatabase::realtimeValueKeys property. When a key is removed from the list, its value is no longer observed and you won't be notified if the value changes in the database.

See also FirebaseDatabase::realtimeValueKeys.


void setUserValue(string key, variant value)

Stores a key-value pair in the Firebase database for the current user. Use the FirebaseDatabase::readCompleted handler to check the result.

In difference to FirebaseDatabase::setValue, this function prepends users/<userId> to the key, so it is accessed from the user-restricted branch. This function will only work, if you use a database structure similar to the one presented in the example.

Note: This function requires Firebase authentication! It will fail if the user is not logged in.

See also FirebaseDatabase::writeCompleted.


void setValue(string key, variant value)

Stores a key-value pair in the Firebase database without authentication. Use the FirebaseDatabase::readCompleted handler to check the result.

See also FirebaseDatabase::writeCompleted.


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Use one IDE to deploy to all supported platforms, including iOS and Android, from a single code base.

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V-Play Multiplayer supports both real-time and turn-based gameplay, so you can use it to make many different types of cross-platform multiplayer games. It's perfect for making player-vs-player games like 'Words with Friends' or games for a large amount of players, such as 'Clash of Clans'.

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The V-Play Game Network is a cross-platform gaming service that allows players around the world to compare game highscores and achievements. Players can also challenge each other across multiple platforms and share their progress on Facebook.

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QML & JavaScript

Qt Meta Language is a highly intuitive reactive language, which is super easy to learn, yet it's extremely powerful and flexible. Mix it with JavaScript to create awesome stuff, with just a few lines of code.

import QtQuick 2.0
import VPlay 2.0

GameWindow {
  Scene {
    
    SimpleButton {
      anchors.centerIn: parent
      text: "Press Me"
      onClicked: {
        console.debug("Wow you pressed me!")
      }
    }
  }
}

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Monetize & Analyze

With V-Play, you can use many 3rd party services for ads, in-app purchases, analytics and more, with just a few lines of code. All of these plugins work cross-platform, which allows you to maintain a single code base.

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Level Editor

The LevelEditor can be used during development to create and modify levels for your game, which you can then bundle in your final publishing build. Additionally, you can also integrate the in-game level editor to your published game and let your gamers create new levels.

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Card Game like UNO, Hearthstone or Poker

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/OneCard/OneCard.pro

Match-3 like Candy Crush Saga

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/JuicySquash/JuicySquash.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/JuicySquashAdvanced/JuicySquashAdvanced.pro

Puzzle like 2048 or Threes!

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/2048/2048.pro

Casino like Big Win Slots

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/FlaskOfRum/FlaskOfRum.pro

Side Scroller like Jetpack Joyride or Flappy Bird

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/FlappyBird/FlappyBird.pro

Tower Defense like Castle Defense or Bloons TD

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/Squaby/Squaby.pro

Falldown & Jump like Doodle Jump or Mega Jump

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/ChickenOutbreak/ChickenOutbreak.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/ChickenOutbreak2/ChickenOutbreak2.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/DoodleJump/DoodleJump.pro

Platformer like Super Mario or Lep's World

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/Platformer/Platformer.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/PlatformerWithLevelEditor/PlatformerWithLevelEditor.pro

Action like Angry Birds, Fruit Ninja, Cut the Rope

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/StackTheBoxWithCommunityEditor/StackTheBoxWithCommunityEditor.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/BalloonPop/BalloonPop.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/CarChallenge/CarChallenge.pro

Arcade like Arkanoid or Space Invaders

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/demos/ZombieBreak/ZombieBreak.pro

Community like Super Mario Maker or Minecraft

We got a demo game for you!

The V-Play SDK includes an open-source demo for this game genre. You can use its source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/examples/Squaby/Squaby.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/StackTheBoxWithCommunityEditor/StackTheBoxWithCommunityEditor.pro

<Path to V-PlaySDK>/Examples/V-Play/demos/PlatformerWithLevelEditor/PlatformerWithLevelEditor.pro

Any other Idea? let us know how we can help you

You are looking for another demo?

The V-Play SDK includes many open-source demos for different game genres. You can use their source code and build your game in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

If you do not find your game genre in this list and wonder if V-Play is the right choice, just contact us, we are happy to help!

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Save up to 90% source code with V-Play, compared to frameworks like Xamarin, Titanium, React Native and others.

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QML & JavaScript

Qt Meta Language is a highly intuitive reactive language, which is super easy to learn, yet it's extremely powerful and flexible. Mix it with JavaScript to create awesome stuff, with just a few lines of code. QML also allows you to easily create smooth and complex animations.

import QtQuick 2.0
import VPlayApps 2.0

App {
  Page {
    
    AppButton {
      anchors.centerIn: parent
      text: "Press Me"
      onClicked: {
        console.debug("Wow you pressed me!")
      }
    }
  }
}

Learn More

Monetize & Analyze

With V-Play, you can use many 3rd party services for ads, in-app purchases, analytics and more, with just a few lines of code. All of these plugins work cross-platform, which allows you to maintain a single code base.

Learn More

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Component Showcase App shows the most important V-Play features and components

We got a demo app for you!

The V-Play SDK includes an open-source demo for this app type. You can use its source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/appdemos/showcase/Showcase.pro

Qt World Summit Conference App a full-featured conference management app made by V-Play

We got a demo app for you!

The V-Play SDK includes an open-source demo for this app type. You can use its source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/appdemos/qtws2016/QtWS2016.pro

Twitter App how to build layouts like in the official Twitter app for iOS and Android

We got a demo app for you!

The V-Play SDK includes an open-source demo for this app type. You can use its source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/appdemos/twitter/Twitter.pro

Maps App displays free bikes or boxes at bike stations for Vienna's bike sharing service Citybike Wien

We got a demo app for you!

The V-Play SDK includes an open-source demo for this app type. You can use its source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/appdemos/maps/Maps.pro

Messaging App demonstrates how to create the UI of a Facebook Messenger like app

We got a demo app for you!

The V-Play SDK includes an open-source demo for this app type. You can use its source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/appdemos/messaging/Messaging.pro

Weather App how to include powerful animations into your user interface

We got a demo app for you!

The V-Play SDK includes an open-source demo for this app type. You can use its source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play.

<Path to V-PlaySDK>/Examples/V-Play/appdemos/waether/Weather.pro

Any other Idea? let us know how we can help you

You are looking for another app demo?

The V-Play SDK includes many open-source demos for different app types. You can use their source code and build your app in record time. After installing V-Play, you can simply open the .pro file with Qt Creator, the development environment used for V-Play..

If you do not find your app type in this list and wonder if V-Play is the right choice, just contact us, we are happy to help!

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