Create Online Quiz - Mobile App | Flutter and Firebase | Online Test App

[Music] we can create this quiz using flutter and Firebase we have already created videos on how to install flutter and create the project the link is in the description we first create a Firebase project in a database as we have already demonstrated in a previous video the link is provided in the description next create a collection with the name quizzes this is the structure of the database collection name quizzes add a document with the name quiz id1 add Fields first add the title field with the data type as a string and the value is quiz one next add the questions field as an array to store multiple questions inside questions create a map for each question add the first question text include options as an array for the multiple option options of the question we will add options later create a field correct option index with the data type as a number add three options include the correct answer index which in this case is index one repeat this process for each question creating a map for each add a total of five questions and options for this project starting from index zero if you need another quiz add a new document and follow the same structure later we will create a video demonstrating how to add quizzes via web interface next open the pubp yaml file and add three dependencies Firebase core Cloud fire store and provider the first two are for accessing the database and the third provider is a state management solution create a new directory named model inside that directory create a model file and name It Quiz model dodart create a question class within this file declare three variables question text options and correct option index question text is a string options is a string array and correct option index is an integer now create a Constructor next Create a quiz class it should contain two variables a string variable called title and a list of questions now create a Constructor create another directory named Services add a dart file inside that directory and name it quore service import Cloud store this package is used to retrieve questions from fire face then import the quore model. dart file create a class named quiz service then create a static method named get quiz data that returns a futured quiz it takes a string quiz ID as a parameter use Firebase fire store to fetch the document snapshot of a quiz with the specified quiz ID Create a quiz object using the data extracted from the quiz snapshot then iter at through the list of questions in the quiz snapshot creating a question object for each question finally the method Returns the created quiz object next create F providers directory inside that directory create a new dart file and name It Quiz service. Dart import the the material. dart and quiz uncore model. files into the quiz uncore service. file then create a class quiz provider with change Notifier within quiz service. Dart change Notifier is a fundamental part of flutter State Management mechanism providing a way to propagate State changes through the widget tree declare four variables first declare a quiz variable with the data type as the quiz class we created earlier then declare three integer variables current index correct answer and selected option each of them is used to store appropriate data next create four Getters these Getters allow other parts of the application to access the current quiz the index of the current question the count of correct answers and the selected option then create another getter for checking the quiz is complete then declares a method named set quiz that takes a single parameter of type quiz named quiz underscore quiz equals quiz this line assigns the value of the quiz parameter to to a private variable underscore quiz it calls the notify listeners method in the context of flutter and State Management this typically signals to any listening widgets that a change has occurred and they may need to rebuild then declare a method named set selected option that takes a single parameter value of type in nullable integer underscore selected option equals value this line assigns the value of the value parameter to a private variable underscore selected option then call the notify listeners method then create a method named answer question there is an outer if condition that checks if the selected option is not null inside this there is an inner if statement that checks if selected option is equal to the correct option index of the current question in the quiz if this condition is true increment the correct answers variable which presumably tracks the number of correct answers in the quiz then increment the current index variable presumably moving to the next question in the quiz next check if the current index is not equal to the total number of questions in the quiz if this condition is true set the underscore selected option variable to null this action is likely performed when moving to the next question possibly resetting the selected option for the new question next create a directory named screens inside the screens directory create a dart file named quiz uncore screen import these packages in the quiz screen file import package flutter slm material. Dart import package provider provider. Dart import quore provider. Dart import quiz uncore service. Dart import quiz model. Dart create a stateless widget named quiz screen create another stateless widget quiz widget inside the same file return the quiz widget in the build function of the quiz screen widget return scaffold in the build function in quiz widget create an instance of the quiz provider class to manage the state future quiz service. getet quiz data quiz ID the method takes a parameter quiz ID which is likely used to identify or fetch a specific quiz the Builder parameter in the future Builder widget is a callback function that defines what should be displayed based on the asynchronous snapshot state it typically takes two parameters context and snapshot first check if the asynchronous operation is still in progress connection state. weting if true return a circular progress indicator indicating that data is still being fetched check if it has an error or is null return an error text the else block handles the successful case when the quiz data has been successfully retrieved it converts the data to a quiz object updates the state using quiz provider. set quiz quiz and returns a quiz widget to display the UI based on the fetched quiz data create another quiz provider instance in quiz widget create app bar body and scaffold add two text widgets inside column add a column that that displays the radio buttons for options add an elevated button to move to the next question include an if condition to check if the quiz is complete if the quiz is complete move to the result page to achieve this we need to create a new result page import the material Dart package create a stateless widget named result page we need to obtain some values from the quiz page so we declare two variables create a Constructor return a scaffold and display the results using the available variable values open Quiz screen and import result page then navigate to the result page using the Navigator do push function open main. Dart initialize Firebase in void main import the provider package also import quiz provider. Dart and quore screen. dart wrap my app with a multi-provider add a change Notifier provider in the provider's list include quiz provider in the cre parameter call the quiz screen widget in the my app widget then run the app the quiz is running select the option finally the result is displayed thank you for watching

Channel: True Coders

Views: 1,146

Keywords: onlinetest, online test, quiz in online flutter, flutter online quiz

Id: OM16WKyugg8

Length: 13min 44sec (824 seconds)

Published: Wed Dec 13 2023