How do I supply an initial value to a text field? Flutter

There are two primary ways to supply an initial value to a text field in Flutter, depending on the widget you are using:

1. Using a TextEditingController (Recommended for state management)¹

2. Using the initialValue property (For stateless fields)²

1. Using a TextEditingController 📝

The most common and flexible way is to use a TextEditingController and set its initial text property.³ This is the recommended approach because the controller is essential for managing and reacting to the text field’s state (getting/setting text, controlling selection, etc.).

Implementation Steps:

1. Create a Controller: Declare and initialize a TextEditingController instance, setting the initial text in its constructor.⁴ This is typically done within the State class’s initState() method or as a class member.

   final myController = TextEditingController(text: 'Initial Text Here');
   

2. Assign the Controller: Pass the controller to the TextField or TextFormField widget’s controller property.

   TextField(
     controller: myController,
     // ... other properties
   )

3. Dispose (Crucial): Remember to dispose of the controller in the dispose() method of your State to free up resources.

   @override
   void dispose() {
     myController.dispose();
     super.dispose();
   }
   

2. Using the initialValue Property ✨

The initialValue property is available only on TextFormField (often used within a Form widget).⁵ It’s a simpler method if you only need to set an initial value and don’t immediately need programmatic control over the text field content (like programmatically changing the text or reading it before form submission).

Implementation Steps:

1. Set initialValue: Directly set the initialValue property of the TextFormField.

   TextFormField(
     initialValue: 'Simple Initial Value',
     // ... other properties (like validator, onSaved)
   )
   

Important Note on initialValue:

• Incompatibility: You cannot use both controller and initialValue simultaneously. If both are provided, the controller takes precedence, and initialValue will be ignored, often resulting in an assertion error during development.

•  If you later need to change the text programmatically or read the text outside of the Form‘s lifecycle (like in an onChanged callback), you will have to create and assign a TextEditingController, making the initialValue irrelevant. This is the case with different State Management Solutions.