PDF converter server running in PhantomJS

server.js

/**
 * Runs a server inside PhantomJS that converts HTML pages to PDF documents
 *
 * Usage: 
 *
 * 1) start application with `phantomjs pdfserver.js <port>`
 *    <port> defaults to 8080
 *
 * 2) Send HTTP Post request to localhost:8080
 *    Pass parameters as JSON object
 *    Parameters: 
 *        - input: Path to input file, either relative or with 'file://...'
 *        - output: Path for output file, relative or absolute path
 *        - format: page format for document, default "A4"
 *        - orientation: page orientation, default: "portrait"
 */

var server = require('webserver').create(),
    page = require('webpage').create(),
    system = require('system'),
    fs = require('fs');

var port = system.args[1] || 8080;
var error = function(response, status, msg) {
    response.statusCode = status;
    response.write(msg);
    response.close();
}

console.log("starting PDF server on port "+ port)
var service = server.listen('127.0.0.1:'+port, function(request, response) {
    var args, input, output, format, orientation;

    try {
        args = JSON.parse(request.post);
    } catch (e) {
        error(response, 400, "Bad parameters, error parsing JSON")
        return;
    }

    input = args.input;
    output = args.output;
    if(!input || !output) {
        error(response, 400, "<em>input</em> and <em>output</em> have to be specified");
        return;
    }
    format = args.format || 'A4';
    orientation = args.orientation || 'portrait';
    page.viewportSize = { width: 600, height: 600 };
    page.paperSize =  { format: format, orientation: orientation, margin: '1cm' };
    if (args.zoom) {
        page.zoomFactor = system.zoom;
    }

    page.open(input, function (status) {
        if (status !== 'success') {
            error(response, 404, "Can't open file");
        } else {
            window.setTimeout(function () {
                page.render(output);
                
                response.statusCode = 200;
                response.write(output);
                response.close();
            }, 200);
        }
    });

});