Render HTML on headless server to produce screenshots - html

Question

I would like to create screenshots of web pages from a given URL. While it's possible to use tools like Selenium RC, that requires a graphical environment. I am running a headless Gentoo server.
This will be part of a tool chain that works like:
Fetch URL
Render HTML
Export render as image file
Store image file

Answer 1

You can run an application with framebuffer X-Server like xvfb - one simple approach is a Qt based app to render the page in a webkit widget and save as an image. Here's a blog post outlining how this can be done with Python.
Here's a quick command line tool I've used with Qt. It's a while since I used it but it should still work!
#include <QtCore/QCoreApplication>
#include <QtGui>
#include <QtWebKit>
#include <QTextStream>
#include <QSize>
QWebView *view;
QString outfile;
void QWebView::loadFinished(bool ok)
{
QTextStream out(stdout);
if (!ok) {
out << "Page loading failed\n";
return;
}
view->page()->setViewportSize(view->page()->currentFrame()->contentsSize());
QImage *img = new QImage(view->page()->viewportSize(), QImage::Format_ARGB32);
QPainter *paint = new QPainter(img);
view->page()->currentFrame()->render(paint);
paint->end();
if(!img->save(outfile, "png"))
out << "Save failure\n";
QApplication::quit();
return;
}
int main(int argc, char *argv[])
{
QTextStream out(stdout);
if(argc < 3) {
out << "USAGE: " << argv[0] << " <url> <outfile>\n";
return -1;
}
outfile = argv[2];
QApplication app(argc, argv);
view = new QWebView();
view->load(QUrl(argv[1]));
return app.exec();
}