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General Form Submission in Flutter

Form submission in Flutter is a common task that involves validating the form’s state and saving the input data. Here’s a general approach to handling form submissions.

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Submission Function

Create a function, typically named _submit, which is responsible for the submission process. 
Future<void> _submit() async {
  // Your submission logic goes here
}

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Form Validation and Saving

  • Validate Form State: Use the form’s global key to access its current state. Call the validate method to ensure all fields pass their individual validation rules.
if (_formKey.currentState == null || !_formKey.currentState!.validate()) {
  // Handle invalid form state
  return;
}
  • Save Form State: Once the form passes validation, call the save method on the form’s current state. This triggers the onSaved callback of each form field, allowing you to store or process the input data.
_formKey.currentState!.save();

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Submission Logic

After validating and saving the form’s state, you can proceed with your submission logic. This might involve making a network request, updating a database, or navigating to another screen.

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Handling Submission States

It’s common to handle various states during submission, such as loading states or error states. Use state management solutions like setState or more advanced state management packages to manage these states effectively.

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Example

Here’s an example of how the _submit function might look: 
Future<void> _submit() async {
  // Check if the form is valid
  if (_formKey.currentState == null || !_formKey.currentState!.validate()) {
    // Handle invalid form state
    return;
  }

  // If the form is valid, save the form state
  _formKey.currentState!.save();

  // Proceed with your submission logic
  // This could involve making a network request, updating a database, etc.
}
This general approach to form submission in Flutter ensures that input data is validated and saved correctly, setting the stage for a successful submission process.