使用PhantomJS和PHP渲染HighCharts

Question

I am trying to render a pie chart on the server using PHP and PhantomJS but I am having no luck so far. I followed a lot of guides and threads here and this is what I have tried so far but I am getting a 0 error code which I have no idea what it means.

pieChart.php

<script src="//code.jquery.com/jquery-1.12.0.min.js"></script>
<script src="//code.jquery.com/jquery-migrate-1.2.1.min.js"></script>
<script src="//code.highcharts.com/highcharts.js"></script>
<script src="//code.highcharts.com/modules/exporting.js"></script>

<div id="container" style="min-width: 310px; height: 400px; margin: 0 auto"></div>

<script>
    $(function () {
        $('#container').highcharts({
            chart: {
                plotBackgroundColor: null,
                plotBorderWidth: null,
                plotShadow: false,
                type: 'pie'
            },
            title: {
                text: 'Browser market shares January, 2015 to May, 2015'
            },
            tooltip: {
                pointFormat: '{series.name}: <b>{point.percentage:.1f}%</b>'
            },
            plotOptions: {
                pie: {
                    allowPointSelect: true,
                    cursor: 'pointer',
                    dataLabels: {
                        enabled: true,
                        format: '<b>{point.name}</b>: {point.percentage:.1f} %',
                        style: {
                            color: (Highcharts.theme && Highcharts.theme.contrastTextColor) || 'black'
                        }
                    }
                }
            },
            series: [{
                name: 'Brands',
                colorByPoint: true,
                data: [{
                    name: 'Microsoft Internet Explorer',
                    y: 56.33
                }, {
                    name: 'Chrome',
                    y: 24.03,
                    sliced: true,
                    selected: true
                }, {
                    name: 'Firefox',
                    y: 10.38
                }, {
                    name: 'Safari',
                    y: 4.77
                }, {
                    name: 'Opera',
                    y: 0.91
                }, {
                    name: 'Proprietary or Undetectable',
                    y: 0.2
                }]
            }]
        });
    });
</script>

Test.js

var page = require('webpage').create();
var url = 'pieChart.php';
page.open(url, function (status) {
    page.render('pieChart.png');
    phantom.exit();
});

Test.php

$error = exec('/usr/bin/phantomjs test.js', $op, $code);
echo $code; // prints 0 on screen