addErrorMessage method

dynamic addErrorMessage(
  1. String attribute,
  2. String message
)

Add a custom error message to a form attribute's existing error messages.

The addErrorMessage function is used to add a custom error message to the existing error messages associated with a specific form attribute. It first checks if the attribute exists in the _attributes map. If the attribute exists, it retrieves the current error messages, adds the new message to the list, and updates the error messages for the attribute using the setErrorMessages function. Additionally, it triggers revalidation for the attribute by calling validate() on its associated form key and updates the error notifier with the updated error messages.

Parameters:

  • attribute: The identifier of the form attribute for which you want to add the custom error message.
  • message: The custom error message to be added to the form attribute's existing error messages.

Implementation

addErrorMessage(String attribute, String message) {
  if (!_attributes.containsKey(attribute)) {
    return;
  }
  List<String> messages = getErrorMessages(attribute) ?? [];
  messages.add(message);
  setErrorMessages(attribute, messages);

  getFormKey(attribute).currentState?.validate();
  _getErrorNotifier(attribute).value = getErrorMessages(attribute);
}