in a civicrm webform, create multiple 'groups' fields

In CiviCRM webform, you can 'enable tag and groups'. Configuring those allows you to create option elements in the webform.

This creates one 'widget', one dropdown or set of checkboxes. I have two field instances where I want the user to select a group - say for example

• which mailing lists do you want to receive (a,b,c)
• what food are you interested in (d,e,f)

a,b,c,d,e and f are all groups. I can not change that.

How could I do that ?

After using Andrew Hunts suggestion for a while, I finally solved this on the server side, in a custom module, using webform logic as described here http://www.webomelette.com/drupal-webform-submission-presave-hook

Basicly, on presave, I look for 2 custom fields containing group ids (mailing and food in the example). Then I add these to the CiviCRM groups field.

I'll add the code below, which has some more logic:

• to make it flexible, I use one hidden field to contain the fieldkey of the civicrm groups selector to add the other fields in. that field is called 'the_groups_element' (but its not the groups element, it contains the key of the groups element)
• there is only one foods group allowed, so before it adds you to a food group, it removes all other food groups from the groups selector.

You could probably make it even more generic, but since I had different logic for the different groups, this was suitable for me.

function getFoodGroups() {
    // return foodgroups
}
function getMailGroups() {
    // return mailgroups
}

function MYMODULE_webform_submission_presave($node, &$submission) {



    $groupselm      = '';
    $groups_cid     = false;
    $foods_cid  = false;
    $mailings_cid = false;

    // http://www.webomelette.com/drupal-webform-submission-presave-hook
    foreach($node->webform['components'] as $cid=>$comp) {
        if ($comp['form_key']=='the_groups_element') {
            $groupselm = $comp['value'];
            break;
        }
    }


    if ($groupselm) {

        foreach($node->webform['components'] as $cid=>$comp) {
            if ($comp['form_key']==$groupselm) $groups_cid = $comp['cid'];
            if ($comp['form_key']=='the_foods') $foods_cid = $comp['cid'];
            if ($comp['form_key']=='the_mailings') $mailings_cid = $comp['cid'];
        }

        $group_gids = $submission->data[$groups_cid];
        if (!$group_gids) $group_gids=array();




        if ($foods_cid!==false && $submission->data[$foods_cid]) {

            // remove all current foods
            foreach ($group_gids as $gidx=>$group_gid) {
                foreach (getFoodGroups() as $foodgroup) {
                    if ($group_gid==$foodgroup['gid']) {
                        if ($debug) drupal_set_message('removing foodgroup '.$foodgroup['gid']);
                        unset($group_gids[$gidx]);
                    }
                }
            }

            // validate and add submitted regions
            $foodsgids = $submission->data[$foods_cid];
            if (!is_array($foodsgids)) $foodsgids = array($foodsgids);
            foreach ($foodsgids as $foodsgid) {
                foreach (getFoodGroups() as $foodgroup) {
                    if ($foodsgid==$foodgroup['gid']) {
                        $group_gids[]=$foodsgid;
                        break; // only one food allowed
                    }
                }
            }
        }

        if ($mailings_cid!==false && $submission->data[$mailings_cid]) {

            // just add submitted mailings, dont remove any
            $mailinggids = $submission->data[$mailings_cid];
            if (!is_array($mailinggids)) $mailinggids = array($mailinggids);
            foreach ($mailinggids as $mailinggid) {
                foreach (getMailGroups() as $mailing) {
                    if ($mailinggid==$mailing['gid']) {
                        if ($debug) drupal_set_message('adding mailing '.$mailing['gid']);
                        $group_gids[]=$mailinggid;
                    }
                }
            }
        }

        $submission->data[$groups_cid] = array_unique($group_gids);

    }