How do I access an iframe from CasperJS?

Spent forever looking for this, and of course I found the answer minutes after posting the question.

I can use the new frame switching commands added to phantomjs in this commit. Specifically, the this.page.switchToChildFrame(0) and this.page.switchToParentFrame() functions. It appears undocumented, and it also seems that the methods have been changed for upcoming releases, but it does work:

var casper = require('casper').create({
    verbose: true,
    logLevel: "debug"
});

casper.start("http://jim.sh/~jim/tmp/casper/main.html", function() {
    this.click('a#main-a');
    this.click('a#main-b');
    this.page.switchToChildFrame(0);
    this.click('a#iframe-c');
    this.page.switchToParentFrame();
});

casper.run(function() {
    this.exit();
});

From 1.0 you can use withFrame

  casper.open("http://www.example.com/page.html", function() {
    casper.withFrame('flashHolder', function() {
      this.test.assertSelectorExists('#the-flash-thing', 'Should show Flash');
    });
  });

As a matter of fact you'll have to use the new --web-security=no feature provided by Phantomjs 1.5 in order to be able to access those iFrames and their contents.