Footer's contents don't seem to work

Question

I'm trying create custom footers such in phantomjs examples: https://github.com/ariya/phantomjs/blob/master/examples/printheaderfooter.js

Here is my code:

var phantom = require('node-phantom');

phantom.create(function (err, ph) {
    ph.createPage(function (err, page) {
         page.set('paperSize', {
              format: 'A4',
              orientation: 'portrait',
              footer: {
                contents: ph.callback(function (pageNum, numPages) {
                  if (pageNum == 1) {
                    return "";
                  }
                  return "<h1>Header <span style='float:right'>" + pageNum + " / " + numPages + "</span></h1>";
                })
              }
         }, function () {
             page.open('http://www.google.com', function () {
              })
         })
    })
});

But unfortunately I get the following error:

TypeError: Object #<Object> has no method 'callback';

Is it bug that ph does not expose callback method?

Answer 1

There are two problems in your script :

• ph is not the classic phantom object, but a proxy object. node-phantom use web sockets to invoke phantomjs. Of course, some features are lost using this implementation.
• functions are not serialized when calling page.set

Printing custom header/footer also requires to call phantom.callback. This method is not documented and so not exposed by node-phantom (and can't be). We need to find a way to apply this method in this package.

There are many solutions. Here is my possible solution :

Serialize your functions in a string in your script

var phantom = require('node-phantom');

phantom.create(function (err, ph) {
    ph.createPage(function (err, page) {
         page.set('paperSize', {
              format: 'A4',
              orientation: 'portrait',
              header: {
                            height: "1cm",
                            contents: 'function(pageNum, numPages) { return pageNum + "/" + numPages; }'
                        },
                        footer: {
                            height: "1cm",
                            contents: 'function(pageNum, numPages) { return pageNum + "/" + numPages; }'
                        }
         }, function () {   
             page.open('http://www.google.fr', function () {        
             page.render('google.pdf');
             ph.exit();
              })
         })
    })
});

edit bridge.js and add phantom.callback + eval. This allow us to re-plug the header/footer .contents.

case 'pageSet':
            eval('request[4].header.contents = phantom.callback('+request[4].header.contents+')');
            eval('request[4].footer.contents = phantom.callback('+request[4].footer.contents+')');
            page[request[3]]=request[4];
            respond([id,cmdId,'pageSetDone']);
            break;

As you can see this works ! (Google in French)