numeric static method

FormFieldValidator<String> numeric([
  1. String? message
])

Validates that the value is numeric.

Implementation

static FormFieldValidator<String> numeric([String? message]) => (value) {
      if (value == null || value.trim().isEmpty) return null;
      if (double.tryParse(value.trim()) == null) {
        return message ?? 'Please enter a valid number';
      }
      return null;
    };