Effortlessly manage items in Flutter ListView

Effortlessly manage items in Flutter ListView

Table of Contents

1. Introduction
2. Overview of the Problem
3. Understanding the Flutter Application
4. Setting up the Dependencies
5. Creating the Card Controller
6. Creating the Card Item Widget
7. Creating the Card Screen
8. Implementing the List View
9. Adding Increment and Decrement Functionality
10. Displaying the Total Payment
11. Navigating to the Payment Gateway
12. Conclusion

Article

Introduction

Welcome back! In this video, we will learn how to add items to the cart logic in Flutter application. We will see how to increment and decrement a counter variable for each respective list item in a list view.

Overview of the Problem

The goal is to Create a list view of cart items, where each item has a price of $50. When we increment a particular item, its value will be added and shown on the total payment button. Conversely, when we decrement, the value will be subtracted from the total. We also want to ensure that we don't allow decrementing beyond 0.

Understanding the Flutter Application

To achieve this, we need to understand the structure of the Flutter application. The main file, main.Dart, will be modified to use the GetX Package for dependency injection. We will create three folders: controllers, custom_widgets, and screens. The controllers folder will contain the CardController class, which will handle the logic for incrementing and decrementing the counter variable. The custom_widgets folder will house the CardItem class, which represents each item in the cart. Finally, the screens folder will contain the CardScreen widget, which displays the list view of cart items.

Setting up the Dependencies

Before diving into the code, we need to import the GetX package and update the MaterialApp to GetMaterialApp in the main.dart file. This allows us to utilize the features of GetX for state management and dependency injection.

Creating the Card Controller

Inside the controllers folder, we will create a new file named card_controller.dart. In this file, we define the CardController class, which extends the GetxController class provided by GetX. We declare an observable variable called total, which will store the total value of the cart. We also define two methods: increment and decrement. These methods accept the price of the item as an argument and update the total variable accordingly.

Creating the Card Item Widget

In the custom_widgets folder, we create a new file named cart_item.dart. This file contains the CardItem class, which is a stateful widget. Each CardItem represents an item in the cart and has two properties: title and price. We use the CardController to access its methods and variables by initializing it within the widget. Inside the build method, we return a Card widget with a ListTile. The ListTile displays the title and uses a Row widget as the trailing property. Inside this row, we have two IconButton widgets for incrementing and decrementing the counter. The counter value is displayed using a Text widget, and we update the counter and call the respective methods of the CardController when the buttons are pressed.

Creating the Card Screen

Next, we create a new file card_screen.dart in the screens folder. The CardScreen is a stateless widget that represents the screen displaying the list view of cart items. We include an AppBar and a ListView widget as its children. To use the CardController in this screen, we need to put it inside the file using Get.put(CardController()). This allows us to access the methods and variables of the controller. In the ListView, we generate a list of CardItem widgets and provide a default price of $50 to each item.

Implementing the List View

On the CardScreen, we call the ListView widget and generate a list of CardItem widgets. Each item will have a unique title and a default price of $50. This creates a scrollable list view of cart items.

Adding Increment and Decrement Functionality

Inside the CardController, we have defined the increment and decrement methods. When the user clicks on the increment button of any list item, we call the increment method and pass the price of that particular item. The price is added to the total variable. Similarly, for the decrement button, we call the decrement method and subtract the price from the total variable. We also added logic to hide the decrement button when the counter is 0 to prevent decrementing to negative values.

Displaying the Total Payment

To display the total payment on the button, we use the obx method provided by GetX for state management. This allows us to listen to changes in the total variable and update the text widget without rebuilding the entire screen. By converting the value of total to a STRING, we can display it on the button using the Text widget.

Navigating to the Payment Gateway

When the user clicks on the total payment button, they can navigate to a payment interface or gateway that has been integrated into the Flutter application. This allows them to complete the payment process seamlessly within the app. If You need assistance with integrating a payment gateway, you can refer to my video on Flutter plus Razer payment gateway integration.

Conclusion

Congratulations on completing the implementation of adding items to the cart logic in a Flutter application! We have learned how to increment and decrement the counter variable for each respective list item in a list view. By utilizing the GetX package for state management and dependency injection, we can easily update the total payment and navigate to the payment gateway. Happy fluttering!

Highlights

• Learn how to add items to the cart logic in a Flutter application
• Increment and decrement a counter variable for each list item in a list view
• Utilize the GetX package for state management and dependency injection
• Create a CardController to handle the logic for incrementing and decrementing
• Implement the CardItem widget to represent each item in the cart
• Create a CardScreen widget for displaying the list view of cart items
• Use the obx method for displaying the total payment dynamically
• Navigate to a payment gateway for completing the payment process

FAQ:

Q: What is the purpose of the GetX package in this application? A: The GetX package is used for state management and dependency injection, making it easier to handle and update variables across different widgets.

Q: Can I customize the price of each item in the cart? A: Yes, you can customize the price of each item by modifying the default price in the CardScreen widget.

Q: How do I integrate a payment gateway into my Flutter application? A: You can refer to the video on Flutter plus Razer payment gateway integration for step-by-step instructions on integrating a payment gateway.