PhantomJS download using a javascript link

Question

I am attempting to scrape the below website:

http://www.fangraphs.com/leaders.aspx?pos=all&stats=bat&lg=all&qual=0&type=8&season=2011&month=0&season1=2011&ind=0&team=0&rost=0&players=0

If you click the small button at the top-right of the table titled "export data", a javascript script runs and my browser downloads the file in .csv form. I'd like to be able to write a PhantomJS script that can do this automatically. Any ideas?

The above button is coded into HTML as such:

<a id="LB_cmdCSV" href="javascript:__doPostBack('LB$cmdCSV','')">Export Data</a></div>

I also found this function in the HTML source code:

<script type="text/javascript">
//<![CDATA[
var theForm = document.forms['form1'];
if (!theForm) {
    theForm = document.form1;
}
function __doPostBack(eventTarget, eventArgument) {
    if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
        theForm.__EVENTTARGET.value = eventTarget;
        theForm.__EVENTARGUMENT.value = eventArgument;
        theForm.submit();
    }
}
//]]>
</script>

I'm very new to PhantomJS/Javascript and could use some pointers here. I think I've found all the info I need to do this automatically (correct me if I'm wrong), but just not sure where to start on coding it. Thanks for any help.

EDIT - This is what my script looks like right now:

var page = new WebPage();
url = 'http://www.fangraphs.com/leaders.aspx?pos=all&stats=bat&lg=all&qual=0&type=8&season=2011&month=0&season1=2011&ind=0&team=0&rost=0& players=0';

page.open(encodeURI(url), function (status){
  if (status !== "success") {
    console.log("Unable to access website");
  } else {
      page.evaluate(function() {
        __doPostBack('LB$cmdCSV', '');
      });
    }
  phantom.exit(0);
});

Answer 1

What have worked very well for me is simulating mouse clicks on the desired element.

page.evaluate(function () {
  var btn = document.getElementById('LB_cmdCSV')
  var ev = document.createEvent('MouseEvent')
  ev.initEvent('click', true, true)
  btn.dispatchEvent(ev)
})