PKPUsageStatsPlugin::templateManagerCallback PHP Method

    function templateManagerCallback($hookName, $params)
    {
        if ($this->getEnabled()) {
            $templateMgr =& $params[0];
            $template = $params[1];
            if ($template == $this->getStatisticsDisplayTemplate()) {
                // Load the JS and CSS for the usage stats graph
                $baseImportPath = Request::getBaseUrl() . DIRECTORY_SEPARATOR . PKP_LIB_PATH . DIRECTORY_SEPARATOR . $this->getPluginPath() . DIRECTORY_SEPARATOR;
                $templateMgr->addStyleSheet('usageStatsGraph', $baseImportPath . 'css/usageStatsGraph.css');
                $templateMgr->addJavaScript('usageStatsGraphHandler', $baseImportPath . 'js' . DIRECTORY_SEPARATOR . 'UsageStatsGraphHandler.js');
                $templateMgr->addJavaScript('chartJS', 'https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.0.1/Chart.js');
            }
        }
    }