Less Repetition: Refactoring Feeds with Abstract Classes

Sometimes, in the flow of development, we end up taking the fastest route: the famous Control + C / Control + V. Recently, I found myself in this situation while developing an app in Flutter. I needed three different feeds: one for followed users, one local, and one global.

The Problem: The Trap of Repetition

In the first version, I had three separate files: HomeFeedScreen, LocalFeedScreen and GlobalFeedScreen. Every time I decided to add a new feature—like a "like" or "reblog" button—I was forced to replicate the code in all three files.

The Solution: Inheritance and Abstract Classes

To solve this, I decided to apply a fundamental concept of Object-Oriented Programming: a abstraction.

Instead of three independent screens, I created one. abstract class which extends State of Flutter. This parent class contains all the common intelligence found in feeds: scroll control, list management, and error handling.

The "trick" was to declare an abstract method called fetchPosts().

How did the code turn out (in practice)?

The structure ended up looking something like this:

The Daughter Classes (Specialization): Now, LocalFeedScreen, HomeFeedScreen, and GlobalFeedScreen are extremely lean. They simply extend the parent class and implement the fetchPosts function, calling the specific endpoint for each one.
The Parent Class (The Template): She takes care of everything that is repetitive. She knows. as display the posts, but don't know which Search for posts.

Image of the Local FeedScreen class — LocalFeedScreen class

Image shows HomeFeedScreen class — Image of the HomeFeedScreen class

Image shows GlobalHomeScreen class. — Image of the GlobalFeedScreen class

The Result

Now, if I want to change the function of feedPost, I change it in a single place. The code became cleaner, easier to read, and above all, scalable. I still intend to improve the organization and perhaps explore other forms of state management, but the simple fact of having eliminated technical redundancy (the famous principle) is already a positive development. DRY – Don't Repeat YourselfThis has already made maintaining this project much more enjoyable.