Is your enhancement related to a problem? Please describe.
I use this plugin as a newsletter signup form on a WordPress site and I would like interest group checkboxes to support a "required" attribute so that form submission is blocked when a specified group checkbox is left unchecked.
Currently, the plugin's required validation only applies to merge fields (e.g. address). Interest group checkboxes — even when left unchecked — do not prevent form submission. This makes it impossible to enforce a GDPR consent checkbox backed by an interest group without custom workarounds. A user can submit the form without checking the consent box, complete the double opt-in flow, and be subscribed with no server-side record that consent was given.
Designs
No mockups provided. The expected behaviour is identical to existing merge field required validation: if a required interest group checkbox is unchecked on form submission, the form returns a localised error message and does not subscribe the user.
Describe alternatives you've considered
I have also considered a JavaScript-only solution that disables the submit button until the checkbox is checked. However, JS-only validation provides no server-side guarantee and can be bypassed, which is insufficient for demonstrable GDPR consent records. A server-side hook (e.g. inside prepare_groups_body() or a new filter before subscribe_to_list() is called) is needed to make this watertight.
I have also considered using the plugin's native GDPR fields feature, but this is not available in the official WordPress plugin — only in Mailchimp's own hosted and embedded forms.
Code of Conduct
Is your enhancement related to a problem? Please describe.
I use this plugin as a newsletter signup form on a WordPress site and I would like interest group checkboxes to support a "required" attribute so that form submission is blocked when a specified group checkbox is left unchecked.
Currently, the plugin's required validation only applies to merge fields (e.g. address). Interest group checkboxes — even when left unchecked — do not prevent form submission. This makes it impossible to enforce a GDPR consent checkbox backed by an interest group without custom workarounds. A user can submit the form without checking the consent box, complete the double opt-in flow, and be subscribed with no server-side record that consent was given.
Designs
No mockups provided. The expected behaviour is identical to existing merge field required validation: if a required interest group checkbox is unchecked on form submission, the form returns a localised error message and does not subscribe the user.
Describe alternatives you've considered
I have also considered a JavaScript-only solution that disables the submit button until the checkbox is checked. However, JS-only validation provides no server-side guarantee and can be bypassed, which is insufficient for demonstrable GDPR consent records. A server-side hook (e.g. inside prepare_groups_body() or a new filter before subscribe_to_list() is called) is needed to make this watertight.
I have also considered using the plugin's native GDPR fields feature, but this is not available in the official WordPress plugin — only in Mailchimp's own hosted and embedded forms.
Code of Conduct