Method addTransitionField

/**
 * Adds a transition field to the form. Can be overwritten by the child class if not needed
 *
 * @param   Form   $form  A Form object.
 * @param   mixed  $data  The data expected for the form.
 *
 * @return  void
 * @since   4.0.0
 */
protected function addTransitionField(Form $form, $data)
{
    $extension = $this->extension . ($this->section ? '.' . $this->section : '');
    $field = new \SimpleXMLElement('<field></field>');
    $field->addAttribute('name', 'transition');
    $field->addAttribute('type', $this->workflowEnabled ? 'transition' : 'hidden');
    $field->addAttribute('label', 'COM_CONTENT_WORKFLOW');
    $field->addAttribute('extension', $extension);
    $form->setField($field);
    $table = $this->getTable();
    $key = $table->getKeyName();
    $id = isset($data->{$key}) ? $data->{$key} : $form->getValue($key);
    if ($id) {
        // Transition field
        $assoc = $this->workflow->getAssociation($id);
        if (!empty($assoc->stage_id)) {
            $form->setFieldAttribute('transition', 'workflow_stage', (int) $assoc->stage_id);
        }
    } else {
        $stage_id = $this->getStageForNewItem($form, $data);
        if (!empty($stage_id)) {
            $form->setFieldAttribute('transition', 'workflow_stage', (int) $stage_id);
        }
    }
}