of static method
- BuildContext context
Returns the FormState of the closest Form widget which encloses the given context.
Typical usage is as follows:
FormState form = Form.of(context);
form.save();
If no Form ancestor is found, this will assert in debug mode, and throw an exception in release mode.
Calling this method will create a dependency on the closest Form in the
context
.
See also:
- Form.maybeOf, which is similar to this method, but returns null if no Form ancestor is found.
Implementation
static FormState of(BuildContext context) {
final FormState? formState = maybeOf(context);
assert(() {
if (formState == null) {
throw FlutterError(
'Form.of() was called with a context that does not contain a Form widget.\n'
'No Form widget ancestor could be found starting from the context that '
'was passed to Form.of(). This can happen because you are using a widget '
'that looks for a Form ancestor, but no such ancestor exists.\n'
'The context used was:\n'
' $context',
);
}
return true;
}());
return formState!;
}