==== Sequential numbers ====

In order to create a sequential (study-)number for each new respondent, you need to create you own respondent controller.\\
Please see the [[devzone:howto:start|howto]] page first, on how to do that.\\
In the code below, you will see three functions in this controller:
  * beforeSave, which will check the respondent number just before saving it
  * createModel, which uses the parent model and creates the new respondent number using an extra variable for organization id as default value (*).
  * getRespNr, which uses the organization ID, gets the latest respondent number for that organization and returns the next respondent number
.
<code php>
  class RespondentController extends Gems_Default_RespondentAction
  {

    /*
     * default value for respnr needed before validation of form
     */
    public function createModel($detailed, $action) {
        $model = parent::createModel($detailed, $action);
        
        $orgcode = $this->loader->getOrganization()->getCode();
        $model->set('gr2o_patient_nr', 'default', $this->getRespnr($orgcode));
        
        return $model;

    } 
  
    

    /*
     * get new studynr if needed and display appropriate message
     */
    public function beforeSave(array &$data, $isNew, Zend_Form $form = null)
    {
                
        If ($isNew) {
        
            //MUtil_Echo::track($data);
            $orgcode = $this->loader->getOrganization($data['gr2o_id_organization'])->getCode();

            $respNr = $this->getRespNr($orgcode);

            if ($data['gr2o_patient_nr'] !== $respNr) {
                $this->addMessage(sprintf($this->_('Studynumber changed from %1$s to %2$s!'), $data['gr2o_patient_nr'], $respNr));
            }else{
                $this->addMessage(sprintf($this->_('Studynumber %s assigned!'), $respNr));
            }
 
            $data['gr2o_patient_nr'] = $respNr;
        }
        return true;
    }
 
  
    /*
     * This function will get the next studynumber for the current organization
     * use gor_code that can be set in the organization interface
     * 
     */

    protected function getRespNr($orgcode)
    {
        $orgcodelength = strlen($orgcode);

        $sql   = "SELECT CAST(substr(`gr2o_patient_nr`,$orgcodelength+1) AS UNSIGNED) AS mynr, `gr2o_patient_nr` 
                  FROM `gems__respondent2org` 
                  WHERE `gr2o_patient_nr` LIKE '$orgcode%' 
                  ORDER BY mynr DESC LIMIT 1;";
        /*
         * This can result in different organisations having identical respnrs if you use orgcodes like A, AB, AC or N, N1, N3, etc ! 
         * It depends on your situation if this is a feature or an unwanted option.
	 * If unwanted you should change this code to fit your needs.
	 * Please note that this is not a problem for Gemstracker as it keeps track of the patient and organization ids.
         */

        $value = $this->db->fetchRow($sql);
        $nr = $value['mynr'];
        $nr++;
        $respnr   = $orgcode.sprintf('%04d', $nr);

        //MUtil_Echo::track($respnr);

        return $respnr;
    }


  }

</code>

(*) In a simalar way you can set defaults for other fields in the createModel function:\\
<code php>
        $model->set('gr2o_consent', 'default', 'Yes');
</code>
or\\
<code php>
        $model->set('grs_gender', 'default', 'M');
</code>