PKPUsageStatsPlugin::logUsageEvent PHP Method

    function logUsageEvent($hookName, $args)
    {
        $hookName = $args[0];
        $usageEvent = $args[1];
        // Check the statistics opt-out.
        if ($this->_optedOut) {
            return false;
        }
        if ($hookName == 'FileManager::downloadFileFinished' && !$usageEvent && $this->_currentUsageEvent) {
            // File download is finished, try to log the current usage event.
            $downloadSuccess = $args[2];
            if ($downloadSuccess && !connection_aborted()) {
                $this->_currentUsageEvent['downloadSuccess'] = true;
                $usageEvent = $this->_currentUsageEvent;
            }
        }
        if ($usageEvent && !$usageEvent['downloadSuccess']) {
            // Don't log until we get the download finished hook call.
            $this->_currentUsageEvent = $usageEvent;
            return false;
        }
        if ($usageEvent) {
            $this->_writeUsageEventInLogFile($usageEvent);
        }
        return false;
    }