Example of onChange at the field level?

[dukedougal]

I can find lots of examples of doing on change at the form level, but no complete examples of how to do it at the field level.

For example I pass the following options into my form but the onChange function never fires.

const options = {
      fields: {
        source_location: {
          access_key_id: this.i18n.Kernel.form.access_key_id,
          onChange: this.onChange,
        },
      }
    };

Is there any fully complete examples showing how to make onchange functions work for specific fields?

thanks

[gcanti]

The onChange handler at the field level is reserved, please use the provided one at the form level (the path argument tells you which field is changed).