yii\console\controllers\AssetController::actionCompress PHP Method

    public function actionCompress($configFile, $bundleFile)
    {
        $this->loadConfiguration($configFile);
        $bundles = $this->loadBundles($this->bundles);
        $targets = $this->loadTargets($this->targets, $bundles);
        foreach ($targets as $name => $target) {
            $this->stdout("Creating output bundle '{$name}':\n");
            if (!empty($target->js)) {
                $this->buildTarget($target, 'js', $bundles);
            }
            if (!empty($target->css)) {
                $this->buildTarget($target, 'css', $bundles);
            }
            $this->stdout("\n");
        }
        $targets = $this->adjustDependency($targets, $bundles);
        $this->saveTargets($targets, $bundleFile);
        if ($this->deleteSource) {
            $this->deletePublishedAssets($bundles);
        }
    }