Rx{Type} vs Rx<Type> vs .obs in GetX state management library of Flutter

Question

Per the documentation:

You have 3 ways to turn a variable into an "observable".

1. The first is using Rx{Type}.

   // initial value is recommended, but not mandatory
   final name = RxString('');
   ...
   

2. The second is to use Rx and use Darts Generics, Rx<Type>

   final name = Rx<String>('');
   ...
   
   // Custom classes - it can be any class, literally
   final user = Rx<User>();
   

3. The third, more practical, easier and preferred approach, just add .obs as a property of your value:

   final name = ''.obs;
   ...
   

How do I decide which method of using observables should be followed in which situation?
Do they all result in exactly same behaviour and only differ by syntax?

Answer 1

The three approaches to using observables in the GetX state management library of Flutter—Rx{Type}, Rx, and .obs—essentially achieve the same behavior of making a variable observable. The difference lies in the syntax and convenience they offer.

1. Rx{Type}: Using the Rx{Type} syntax allows you to create an observable variable without specifying an initial value. However, it is recommended to provide an initial value to the observable for better type inference and improved performance.

Example: dart

final name = RxString('');

2. Rx: Using Rx syntax involves using Dart's generics to specify the type of the observable variable. This approach is useful when dealing with custom classes or more complex data types.

Example: dart

final name = Rx<String>('');
final user = Rx<User>();

3. .obs: The .obs syntax is a shorthand and the preferred approach in GetX. It allows you to mark a value as observable by simply adding .obs as a property to the value. This approach is more concise and easier to use, especially when dealing with basic data types like strings, numbers, and booleans.

Example: Dart

final name = ''.obs;

All three methods result in the same behavior of creating an observable variable that can be used within the GetX state management framework. The choice between them mainly depends on personal preference, code readability, and the complexity of the data types you're working with.

In general, the .obs syntax is recommended as the preferred approach due to its simplicity and ease of use. It is suitable for most scenarios, especially when dealing with basic data types. If you have custom classes or more complex data structures, using Rx can be more appropriate. However, you can choose any of these approaches based on your specific requirements and coding style.