使用href / Javascript访问锚

Question

Testing CasperJS on a system that has an anchor with an href attached to javascript. Doing the usual

casper.then(function() {
this.evaluate(function() {
//      document.querySelector('a[id="CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH"]').click();    // works in FF
//  window.onload=submitAction_win0(document.win0,'CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH');

      //eval("submitAction_win0(document.win0,'CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH_1');");
//submitAction_win0(document.win0,'CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH');
//  window.onload=submitAction_win0(document.win0,'CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH');

//      this.click('a[id="CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH"]');
//      click('a[id="CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH"]');
//      self.click('a[id="CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH"]');
//      this.this.click('a[id="CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH"]');
..

});

});

None of the above approaches worked. The Git repos for the projects indicate that Casper has a CasperUtils/ClientUtils lib that appears to have a __utils__ that has a click method which is the way to invoke href="javascript:foo()" elements.

However, I can't seem to figure out how to get this running.

If anyone has used CasperJS, and has a sample of code on how this is implemented, we'd be thankful!

Ideally, the end result should be something like:

casper.then(function() {
  e=document.querySelector("id['foo']");
  CasperUtilsSomething.click(e);
});

Or, if you have a pointer to a test code case that I could run, that would let us see how this is supposed to be implemented.

Answer 1

It looks like the issue here is a confusion around the scope of the function. This is the tricky thing about working with PhantomJS (which CasperJS is built on top of) - there are two entirely separate scopes, one of which runs in the PhantomJS context and has access to the casper object, and the "sandbox" scope that remote code runs in - anything run in casper.evaluate() , for example, is run in a sandbox in the remote context, with no access to the casper object or its methods.

So trying to call this.click() within casper.evaluate() is going to fail - the function you're running has no access to the casper instance, and this will refer to the window object in the browser.

Usually, the way you'd do this is just:

casper.then(function() {
    casper.click('#CLASS_SRCH_WRK2_SSR_PB_CLASS_SRCH');
    casper.evaluate(function() {
        // some function that needs to run after clicking
    });
});

Note also that as far as I know, you generally can't run any window.onload code in casper.evaluate() - the window's load event will already have fired by the time you are running your code.