java - How to use the browser's (chrome/firefox) HTML/CSS/JS rendering engine to produce PDF?

Question

There are nice projects that generate pdf from html/css/js files

1. http://wkhtmltopdf.org/ (open source)
2. https://code.google.com/p/flying-saucer/ (open source)
3. http://cssbox.sourceforge.net/ (not necessarily straight pdf generation)
4. http://phantomjs.org/ (open source allows for pdf output)
5. http://www.princexml.com/ (comercial but hands down the best one out there)
6. https://thepdfapi.com/ a chrome modification to spit pdf from html from

I want to programatically control chrome or firefox browser (because they both are cross platform) to make them load a web page, run the scripts and style the page and generate a pdf file for printing.

But how do I start by controlling the browser in an automated way so that I can do something like

render-to-pdf file-to-render.html out.pdf

I can easily make this job manually by browsing the page and then printing it to pdf and I get an accurate, 100% spec compliant rendered html/css/js page on a pdf file. Even the url headers can be omitted in the pdf through configuration options in the browser. But again, how do I start in trying to automate this process?

I want to automate in the server side, the opening of the browser, navigating to a page, and generating the pdf using the browser rendered page.

I have done a lot of research I just don't know how to make the right question. I want to programatically control the browser, maybe like selenium does but to the point where I export a webpage as PDF (hence using the rendering capabilities of the browser to produce good pdfs)

Answer 1

I'm not an expert but PhamtomJS seems to be the right tool for the job. I'm not sure though about what headless browser it uses underneath (I guess it is chrome/chromium)

var page = require('webpage').create();
page.open('http://github.com/', function() {
     var s = page.evaluate(function() {
         var body = document.body,
             html = document.documentElement;

        var height = Math.max( body.scrollHeight, body.offsetHeight, 
            html.clientHeight, html.scrollHeight, html.offsetHeight );
        var width = Math.max( body.scrollWidth, body.offsetWidth, 
            html.clientWidth, html.scrollWidth, html.offsetWidth );
        return {width: width, height: height}
    });

    console.log(JSON.stringify(s));

    // so it fit ins a single page
    page.paperSize = {
        width: "1980px",
        height: s.height + "px",
        margin: {
            top: '50px',
            left: '20px'
        }
    };

    page.render('github.pdf');
    phantom.exit();
});

Hope it helps.