Creating a Flot chart using node-canvas

node-flot.js

var document = require("jsdom").jsdom(),
    window = document.createWindow(),
    jQuery = require('jquery').create(window),
    fs = require('fs'),
    script = document.createElement("script");

window.Canvas = require('canvas');
script.src = 'https://gist.github.com/raw/790339/3b0171c3e9b749bb93fff5d642eaa687f02939a5/jquery.flot.node-canvas.js';
script.onload = function ()
{
    var i, d1 = [], d2 = [], d3 = [];
    for (i = 10; --i;) d1.push([i, parseInt(Math.random() * 30)]);
    for (i = 10; --i;) d2.push([i, parseInt(Math.random() * 30)]);
    for (i = 10; --i;) d3.push([i, parseInt(Math.random() * 30)]);

    var defaults = { 
        lines: { show: true, fill: true, steps: false },
        bars: { show: false, barWidth: 0.6 }
    };

    var data = [
        jQuery.extend(true, {}, defaults, {data: d1}),
        jQuery.extend(true, {}, defaults, {data: d2}),
        jQuery.extend(true, {}, defaults, {data: d3})
    ];

    var options = {
        width: 600, height: 300, 
        grid: {clickable: true, hoverable: true} 
    };

    var placeholder = jQuery(''), // empty jQuery object
        plot = jQuery.plot(placeholder, data, options),
        node_canvas = plot.getCanvas(),
        ctx = node_canvas.getContext('2d'),
        out = fs.createWriteStream(__dirname + '/flot.png'),
        stream = node_canvas.createPNGStream();

    stream.on('data', function ( chunk ) {
        out.write(chunk); 
    });
};
document.head.appendChild(script);

I did a quick test and it ran fine in 0.2.6 but segfaulted with 0.3.8. Some quick debugging showed it failing after the call to jQuery.plot.

I'll do some more digging soon, especially with node 0.4 right around the corner, but I think the issue is with node-canvas.

I've done some follow up with this and took a different approach using jsdom.jquerify as a wrapper. Unfortunately, I ran into a dispatchEvent issue with my node-canvas going through jsdom's level2-events. Will require further investigation but I do believe there may be some integration issues with node-canvas.

@mgan59 see my updated gist @ https://gist.github.com/842175 which uses jsdom 0.2.0