Solving the onEditingComplete Issue in Flutter: The Role of the Focus Widget

Описание: Discover how to ensure that `onEditingComplete` is called effectively in Flutter when changing focus between TextFields, using the `Focus` widget.
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This video is based on the question https://stackoverflow.com/q/65634007/ asked by the user 'Daniel Porteous' ( https://stackoverflow.com/u/3846032/ ) and on the answer https://stackoverflow.com/a/65767705/ provided by the user 'Baker' ( https://stackoverflow.com/u/2301224/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Understanding the onEditingComplete Issue in Flutter

When working with text input in Flutter, many developers face a common issue: the onEditingComplete function doesn't get called when a user taps on a different field to change focus. This can lead to frustration, particularly when ties are crucial to ensure proper form submission or data cleaning actions are executed.

In this guide, we'll delve into the problem of managing focus in TextField widgets and provide a clear solution to ensure onEditingComplete gets called consistently, no matter how focus is changed.

The Problem

In Flutter, the onEditingComplete function is designed to execute code when the user has finished editing a field, typically triggered by pressing the “Next” or “Done” button on the keyboard. However, when a user taps on a different field, the function is not called, creating gaps in the intended behavior.

Here’s a brief recap of how the TextField is usually implemented:

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

Example Scenario

A case where this issue is prevalent is during forms with multiple input fields. Let's suppose we have two fields: "Name" and "Password", where the following expectations reside:

Tapping "Next" should call the onEditingComplete for the current field.

Tapping directly on the "Password" field should also trigger the same function intended for "Name".

Unfortunately, due to the default behaviors of TextField, the second scenario leaves you without a call to onEditingComplete.

Providing a Solution with the Focus Widget

To tackle this issue and ensure a seamless user interaction experience, we can use the Focus widget in Flutter. This widget can handle focus loss events and allows us to implement custom behavior when a field loses focus.

How the Focus Widget Works

The Focus widget wraps the TextField and listens for focus changes. You can make use of the onFocusChange callback to perform actions that should occur when the input field loses focus, independent of whether the loss of focus is due to tapping another field or pressing the keyboard buttons.

Here’s how to implement this solution:

Implementation Steps

Wrap your TextField with the Focus Widget: This allows it to handle focus events.

Utilize the onFocusChange call: This callback will invoke any necessary functions when the field changes focus.

Here’s an example implementation:

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

Key Components of the Implementation

Focus Widget: Wraps the TextField, enabling focus event handling.

onEditingComplete function: This will still handle the software keyboard actions (i.e., “Next” and “Done”).

onFocusChange handler: This callback executes every time the focus changes, allowing you to perform necessary cleanup or action tasks.

Conclusion

Managing focus effectively in Flutter's TextField can greatly enhance user experience. By utilizing the Focus widget, you can ensure that your onEditingComplete logic runs smoothly whether users are tapping to switch fields or using the keyboard. This approach not only solves the issue but also allows you to write cleaner, more maintainable code.

Implement this solution in your Flutter applications to streamline user interactions and maintain the integrity of your data handling.