11.2. Working with forms in Flutter: Adding text fields

Working with forms in Flutter is an essential part of app development. Forms allow users to interact with the application, providing information and making selections. A fundamental component of any form is the text field. This tutorial will walk you through the process of adding text fields to a form in Flutter.

Before we get started, it's important to have a basic understanding of Flutter. Flutter is a user interface (UI) development kit created by Google. It allows developers to build native iOS and Android apps from a single codebase. Dart is the programming language used to write Flutter code.

To start working with forms in Flutter, you will first need to create a new Flutter project. Once you have your project set up, you can start adding text fields to your form.

In Flutter, a text field is represented by the TextFormField widget. This widget displays a text field that can be filled in by the user. To add a TextFormField to a form, you first need to wrap the widget in a Form widget. The Form widget provides a lot of useful functionality for working with forms, such as validating and saving data.

Here is an example of how you can add a TextFormField to a Form:

<Form>
  <TextFormField>
    labelText: 'Type your name',
    validator: (value) {
      if (value.isEmpty) {
        return 'Please enter some text';
      }
      return null;
    },
  </TextFormField>
</Form>

In this example, the text field displays the message 'Type your name' when it is empty. The validator function is used to check if the text field is empty. If so, the function returns an error message. Otherwise, it returns null, indicating that there are no errors.

You can add as many TextFormField to your Form as you like. Each TextFormField can have its own validator function and other custom properties. For example, you can use the obscureText property to create a password field that obscures the text as the user types.

In addition to text fields, you can also add other types of fields to your form. For example, you can add checkboxes, radio buttons and sliders. Each of these widgets has its own syntax and set of properties, but they can all be used inside a Form widget.

Once you have added all the desired fields to your form, you can use the Form widget's save function to save the form data. This function will call the onSave function for each form field, allowing you to save the data in a location of your choosing.

In summary, working with forms in Flutter involves creating a Form widget and adding text fields or other fields to the form. Each field can have its own custom properties and validation functions. Once the form is complete, you can use the save function to save the form data.

I hope this tutorial has given you a good overview of how to work with forms in Flutter. With a little practice, you'll be able to create complex, interactive forms that allow users to interact with your application in meaningful ways.

Next page of the Free Ebook:

151Working with forms in Flutter: Field validation

3 minutes