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The Flutter GetX Ecosystem

Workers

Explore the concept of Workers in Flutter GetX which automate reactions to changes in reactive variables. Learn to use different worker methods such as ever, once, debounce, and interval to manage state updates efficiently. This lesson helps you understand how to handle real-time data changes and optimize your app’s responsiveness.

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Introduction to workers

The beauty of reactive programming is that we do not have to worry about every event that occurs. We just have to define a scenario and write the code to handle that scenario. Workers in GetX are functions that allow us to define actions and map them to a reactive variableA reactive variable is a type of variable that automatically updates and notifies its listeners or observers when its value changes, allowing for real-time data synchronization and dynamic user interfaces.. When that variable’s value changes, the action is performed. Simple as that! But wait, there’s more—there are five kinds of workers in the framework, and each of them has a slightly different use case. Let’s explore them one by one!

The ever method

ever is the most straightforward worker—it performs the action every time the value of the input variable changes. In the code snippet below, we define a reactive variable count of type RxInt (though any data type would do) and input it into the method. As for the action, we log an analytics event every time the value of count changes.

Dart
// Reactive variable
final RxInt count = 0.obs;
// Logs analytics every time user changes the count
ever<int>(count, (value) => logAnalyticsEvent('Count changed to $value'));

We also need to provide the data type to the worker, which is int in this case.

Condition

We get additional control over the updates with the condition parameter. It is of dynamic type, so we can provide it a bool directly or assign a callback that returns a bool. Below, we have added the condition that the value of count should be greater than 5.

Dart
ever<int>(
	count,
  (value) => logAnalyticsEvent('Count changed to $value'),
  condition: () => count.value > 5,
);

In this case, the analytics are logged only when the condition is met. ...