Souke/console/config/backend/controllers/StatsController.php

<?php

namespace backend\controllers;

use yii\web\Controller;
use yii\filters\AccessControl;
use Yii;
use common\models\User;
use common\models\Commande;
use DateTime;
use DateInterval;
use DatePeriod;

class StatsController extends BackendController {

    public function behaviors() {
        return [
            'access' => [
                'class' => AccessControl::className(),
                'rules' => [
                    [
                        'allow' => true,
                        'roles' => ['@'],
                        'matchCallback' => function ($rule, $action) {
                            return Yii::$app->user->identity->status == USER::STATUS_ADMIN 
                                    || Yii::$app->user->identity->status == USER::STATUS_BOULANGER;
                        }
                    ]
                ],
            ],
        ];
    }

    public function actionIndex() {

        /*
         *  Volume de commande de l'année passée (par mois)
         */

        $date_start = date('Y-m-d', time() - 60 * 60 * 24 * 365);
        $date_end = date('Y-m-d');

        $data_pain = [];

        // labels
        $data_labels = [];

        $start = new DateTime($date_start);
        $interval = new DateInterval('P1M');
        $end = new DateTime($date_end);

        $period = new DatePeriod($start, $interval, $end);

        foreach ($period as $date) {
            $mois = date('m/Y', $date->getTimestamp());
            $data_labels[] = $mois;
            $data_pain[$mois] = 0;
        }

        // commandes
        $commandes = Commande::find()
                ->with('commandeProduits')
                ->joinWith('production')
                ->where('production.date > ' . $date_start)
                ->andWhere('production.id_etablissement = ' . Yii::$app->user->identity->id_etablissement)
                ->all();

        foreach ($commandes as $c) {
            $c->init();
            $mois = date('m/Y', strtotime($c->production->date));
            if (isset($data_pain[$mois])) {
                $data_pain[$mois] += $c->montant_pain;
            }
        }

        // création d'un tableau sans index car chart.js n'accepte pas les index 
        $data_pain_noindex = [];
        foreach ($data_pain as $key => $val) {
            $data_pain_noindex[] = $val;
        }

        return $this->render('index', [
            'data_labels' => $data_labels,
            'data_pain' => $data_pain_noindex,
        ]);
    }

}

?>