public function definition_after_data() {
        $mform = $this->_form;
        $cohortfile = $mform->getElementValue('cohortfile');
        $allowsubmitform = false;
        if ($cohortfile && ($file = $this->get_cohort_file($cohortfile))) {
            // File was uploaded. Parse it.
            $encoding = $mform->getElementValue('encoding')[0];
            $delimiter = $mform->getElementValue('delimiter')[0];
            $contextid = $mform->getElementValue('contextid')[0];
            if (!empty($contextid) && ($context = context::instance_by_id($contextid, IGNORE_MISSING))) {
                $this->processeddata = $this->process_upload_file($file, $encoding, $delimiter, $context);
                if ($this->processeddata && count($this->processeddata) > 1 && !$this->processeddata[0]['errors']) {
                    $allowsubmitform = true;
                }
            }
        }
        if (!$allowsubmitform) {
            // Hide submit button.
            $el = $mform->getElement('buttonar')->getElements()[0];
            $el->setValue('');
            $el->freeze();
        } else {
            $mform->setExpanded('cohortfileuploadform', false);
        }

    }