Forms & Validation
Form, TextFormField, GlobalKey<FormState>, validators, focus management, input types
1What is the main role of the Form widget in Flutter?
What is the main role of the Form widget in Flutter?
Answer
The Form widget serves as a container to group and manage multiple form fields (FormField). It allows validating, saving, and resetting all fields in a single operation via FormState. Without Form, each field would need to be managed individually.
2How to access FormState to trigger form validation?
How to access FormState to trigger form validation?
Answer
To access FormState, a GlobalKey<FormState> must be assigned to the Form's key property. Then, the currentState property of this key provides access to FormState and its methods validate(), save(), and reset().
3What is the difference between TextField and TextFormField?
What is the difference between TextField and TextFormField?
Answer
TextFormField is a version of TextField integrated with Form. It inherits from FormField and has a validator property that automatically integrates with FormState.validate(). TextField cannot directly participate in grouped Form validation.
What does the validator property of a TextFormField return to indicate an error?
What is the purpose of the autovalidateMode property of a Form?
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