Open URL from file system using PhantomJS - phantomjs

Question

In page.open I can read about how to open a page using http.
How do use the WebPage module to open an url from the file system?
I have tried to omit http:// and have an url with ../some_dir/foo.html, but it seems to fail.
I Have tried this:
var page = require('webpage').create();
var fs = require('fs');
fs.changeWorkingDirectory('../foo/bar');
page.open('file://index.html', function(status)
{
console.log(status);
//console.log(document.title);
phantom.exit();
});
which outputs "fail".
I got the advice to test an absolute path, trying this:
var page = require('webpage').create();
var fs = require('fs');
page.open('file:///absolute/path/to/index.html', function(status)
{
console.log(page.title);
console.log($('body').length);
phantom.exit();
});
(with and without the call to changeWorkingDirectory, but with the same result)
I get a page title, but phantomjs reports that $ is undefined, jQuery is included in my html file (that is too large to post here). It is included like this:
<script type="text/javascript" src="js/jquery-1.11.1.min.js"></script>
Trying to run functions also produces errors like
Can´t find variable: function_name

Answer 1

Does the page/file you are opening already have jquery embedded on the page? If not, you will need to use either injectJs or includeJs on the page object before you can use the $ operator.
http://phantomjs.org/page-automation.html
If you are just doing a simple DOM selection, I would recommend just calling
document.querySelector('body').length
As these functions already exist within the Phantom instance.