CiviCRM Community Forums (archive)

/**
 * buildForm hook that would allow contacts to renew only existing memberships.
 */
function civitest_civicrm_buildForm( $formName, &$form ) {
    if ( $formName == 'CRM_Contribute_Form_Contribution_Main' ) {
        if ( is_array( $form->_membershipBlock ) ) {
            //get logged in contact
            $session   = & CRM_Core_Session::singleton();
            $contactID = $session->get('userID');
           
            //check for existing membership
            $query = "SELECT membership_type_id
                      FROM civicrm_membership
                      WHERE membership_type_id IN ( {$form->_membershipBlock['membership_types']} )
                         AND civicrm_membership.contact_id = {$contactID}";
            $dao = CRM_Core_DAO::executeQuery( $query );

            $membershipTypeID = null;
            while ( $dao->fetch( ) ) {
                $membershipTypeID = $dao->membership_type_id;
            }

            if ( $membershipTypeID ) {
                $form->freeze(array('selectMembership'));   
                $defaults['selectMembership'] = $membershipTypeID;
                $form->setDefaults( $defaults );
            }   
        }
    }
}