When you hit the url for Dojo Demo the page you hit is the html page.

Once the page is loaded a call goes to url 'http://dojotoolkit.org/documentation/tutorials/1.6/datagrid/demo/hof-batting.json' to pull the JSON data.

my $mech = WWW::Mechanize->new();<br>
$mech->get('http://dojotoolkit.org/documentation/tutorials/1.6/datagri
+d/demo/hof-batting.json');<br>
[download]

To extract data from content there are alternatives:
1. Using simple regular expression you can pull the required data.

2. Convert JSON to array of hashes and pull the required data.

Let me know if it helps.