lib/controllers/ObjectController.php
public function actionSetPrimary()
    {
        $p = $this->_parseParams();
        $this->_checkParams($p, ['type', 'object', 'relation']);
        $this->params = &$p;

        if (!$p['object']->can('update')) {
            throw new HttpException(403, "You do not have access to update the {$p['type']->title->getPlural(true)} '{$p['object']->descriptor}'");
        }

        Yii::$app->response->view = false;
        Yii::$app->response->task = 'status';

        if (!$p['relation']->setPrimary($p['relationshipRole'])) {
            Yii::$app->response->error = 'Unable to set relationship as primary!';
        } else {
            Yii::$app->response->task = 'status';
            Yii::$app->response->success = '<em>' . $p['object']->descriptor . '</em> was set as primary!';

            $primaryModelClass = get_class($p['object']);
            Yii::$app->response->trigger = [
                ['refresh', '.model-' . $primaryModelClass::baseClassName()],
            ];
        }
    }
public function actionSetPrimary()
    {
        $p = $this->_parseParams();
        $this->_checkParams($p, ['type', 'object', 'relation']);
        $this->params = &$p;

        if (!$p['object']->can('update')) {
            throw new HttpException(403, "You do not have access to update the {$p['type']->title->getPlural(true)} '{$p['object']->descriptor}'");
        }

        Yii::$app->response->view = false;
        Yii::$app->response->task = 'status';

        if (!$p['relation']->setPrimary($p['relationshipRole'])) {
            Yii::$app->response->error = 'Unable to set relationship as primary!';
        } else {
            Yii::$app->response->task = 'status';
            Yii::$app->response->success = '<em>' . $p['object']->descriptor . '</em> was set as primary!';

            $primaryModelClass = get_class($p['object']);
            Yii::$app->response->trigger = [
                ['refresh', '.model-' . $primaryModelClass::baseClassName()],
            ];
        }
    }
[[@doctodo method_description:actionSetPrimary]].

@throws HttpException [[@doctodo exception_description:HttpException]]