Filter webform options from external source by field value

Question

I have an options field which is sourced from an external json file using the following code.

$nsbooks_url = 'https://mysite.com/myjson.json';
$preoptions = json_decode(file_get_contents($nsbooks_url), TRUE);
$options = array_column($preoptions, 'Document Number');
\Drupal::cache()->set('nsbooks', $options);

The JSON file contains these lines.

[{
    "custid": "88149",
    "recordType": "salesorder",
    "Document Number": "SO7878"
}, {
    "custid": "89757",
    "recordType": "salesorder",
    "Document Number": "SO1226"
}]

In the webform, I have another field where the user enters their customer ID number. (custid in the JSON file.)

What I am trying to do is filter the JSON file so that only document numbers that match that customer ID number are shown as an option. How can I achieve this?

Answer 1

I think thats not possible without writing own code.

Try to alter the webform with the hook your_module_webform_submission_form_alter and add an ajax callback to the customer ID number field, which updates the options. To accomplish this, you can take a look at https://www.hashbangcode.com/article/drupal-9-cascading-ajax-select-forms.