How to Filter JSON Data in Flutter Based on Another JSON Structure

Learn how to filter JSON data in Flutter based on pet types in another JSON structure using simple looping techniques.
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Mastering JSON Filtering in Flutter: A Step-by-Step Guide

When dealing with mobile app development in Flutter, data management is a common challenge developers face. In particular, filtering data from multiple JSON structures can get tricky. If you’re grappling with how to filter one list of products based on another list of categories, you’re not alone! In this guide, we will dive into a practical solution for filtering products based on selected pet types extracted from another JSON data source. Let’s break this down into manageable parts.

Understanding the Problem

Imagine you have two JSON data structures:

Product List - Contains products along with their associated categories.

Category List - Details categories and their applicable pet types.

Here’s a quick overview of the data:

Example JSON Structures

Product List (prdctList):

[[See Video to Reveal this Text or Code Snippet]]

Category List (prdctCtgrList):

[[See Video to Reveal this Text or Code Snippet]]

User Interaction

You want to filter out products based on the pet type selected by the user. For example:

If the user selects "Cat," both "product 1" and "product 2" should appear in the results.

If the user selects "Dog," only "product 2" should be displayed.

Solution: Filtering with Loops

The solution for filtering this data efficiently lies in using loops. Let’s walk through the steps to implement this in your Flutter app.

Step 1: Data Preparation

Make sure both JSON data sources are properly loaded into your application. You’ll need to parse the JSON into Dart objects (lists and maps) that you can work with.

Step 2: Implementing the Loop

To filter the products based on the selected pet type, you can loop through the prdctCtgrList to check each category's pet_type. If the category matches the selected pet type, you can then check which products fall into that category. Here’s a simple example code to illustrate:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Handling User Selection

When the user selects a pet type from your interface (such as a button or dropdown), simply call the filterProductsByPetType function with the chosen type as an argument. This will trigger the filtering process and give you the desired results.

Conclusion

Filtering JSON data in Flutter can be straightforward when you break down the problem into smaller parts. By leveraging loops to compare and filter data, you can dynamically show products based on user preferences. This method not only enhances user experience but also ensures that your application stays clean and manageable. Happy coding!