Flutter - Async Validator of TextFormField

Question

In my app the user has to insert a name in the textformfield. While the user is writing a query should be made to the database, that controls if the name already exists. Thi

Answer 1

Perhaps you could run your async check using the onChange handler and set a local variable to store the result.

Something like:

TextFormField(
  controller: recipeDescription,
  decoration: InputDecoration(hintText: "Beschreibe dein Rezept..."),
  keyboardType: TextInputType.multiline,
  maxLines: null,
  maxLength: 75,
  onChanged: (text) async {
    final check = await checkRecipe(text);
    setState(() => hasRecipe = check);
  },
  validator: (_) => (hasRecipe) ? "Exists" : null,
)