Piwik\Plugins\CoreVisualizations\Visualizations\Sparkline::render PHP Method

    public function render()
    {
        // If period=range, we force the sparkline to draw daily data points
        $period = Common::getRequestVar('period');
        if ($period == 'range') {
            $_GET['period'] = 'day';
        }
        $this->loadDataTableFromAPI();
        // then revert the hack for potentially subsequent getRequestVar
        $_GET['period'] = $period;
        $values = $this->getValuesFromDataTable($this->dataTable);
        if (empty($values)) {
            $values = array_fill(0, 30, 0);
        }
        $graph = new \Piwik\Visualization\Sparkline();
        $graph->setValues($values);
        $height = Common::getRequestVar('height', 0, 'int');
        if (!empty($height)) {
            $graph->setHeight($height);
        }
        $width = Common::getRequestVar('width', 0, 'int');
        if (!empty($width)) {
            $graph->setWidth($width);
        }
        $graph->main();
        return $graph->render();
    }