Efficiently Filtering Nested Lists in Flutter/Dart

Learn how to effectively filter nested lists in Flutter/Dart based on parent and child properties, eliminating duplicates while maintaining structure.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Flutter/Dart- Filter nested list

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Efficiently Filtering Nested Lists in Flutter/Dart

When working with data in Flutter or Dart, it's common to encounter scenarios where you need to filter through nested lists. For instance, you might have a list of objects, each containing additional nested objects, and you want to filter this list based on certain criteria. In this guide, we'll explore how to filter nested lists effectively, specifically focusing on filtering based on the name property of both parent and child objects.

The Problem

Imagine you have a list of objects that look something like this:

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

You want to filter this list to find items containing the substring "Subtesting 123" in the parent name or in any of the subNames. However, the challenge you've faced with your initial approach is that it results in duplicate entries.

The Solution

To achieve a clean and effective solution, we can utilize Dart's strong type system with custom model classes. This will help us avoid working with raw JSON, making our code easier to read and maintain.

Step 1: Define Model Classes

First, we'll create classes to represent our data structure. This includes a Model for the parent objects and a SubNames class for the nested objects.

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

Step 2: Transform the Raw Data

Next, we will convert our rawData into a list of our Model objects:

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

Step 3: Filter the List

Now that we have our data in a usable format, we can filter it based on our criteria. Using the where method, we can check if either the parent name or any of the child names contain the desired substring.

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

Step 4: Print the Results

Finally, we can output the filtered results:

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

Conclusion

By using custom model classes and leveraging Dart's powerful collection methods, you can effectively filter nested lists without introducing duplicates. This not only makes your code cleaner but also improves maintainability. The approach outlined above is not just applicable in Dart; it can be adapted to various programming scenarios dealing with complex data structures.

Feel free to adapt the code to your specific needs and see how easy it is to manage and filter nested data structures!