Need help understanding key events with setData calls

I'm having the following problem that I can't figure out.  I'm wondering if what I am trying to do is even possible within the ckeditor architecture.

Here's my business use case:

1) Listen to any keyup events on the editor

2) When a URL is detected (e.g. "ckeditor.com"), automatically insert HTML formatting to update the editor using setData call.  This can be as simple as just writing "<a>ckeditor.com</a>" to render with the link plugin

Here's a simplified version of the code:

main: function() {
var self = this
$(document).ready(function () {
    CKEDITOR.replace("post-message", {
    removePlugins: "scayt,tabletools,contextmenu,toolbar,menubutton,elementspath",
    allowedContent: true,
    on: {
           key: self.updateMessage
    }
  });
});
}

updateMessage: function(evt) {
    var text = CKEDITOR.instances["post-message"].getData();
    //Parse text and insert <a> tags...
    console.log(text); //Verify the text is changed
    CKEDITOR.instances["post-message"].setData(text);
}

The problem is that the getData() function on the first invocation returns a blank string and the caret position in the editor is always reset to the beginning of the editor after the call to setData.  As a result, anything I type into the editor never gets displayed.

If I remove the call to setData I can see the console.log(text) statement showing my expected HTML formatted string.

My question is whether this approach even works or should I be listening to another event in the editor altogether (e.g. afterSetData and then somehow change updateMessage function to use some other way to update the editor contents)?  Should I somehow figure out how to intercept where the text/HTML gets written to the editor and apply my URL filtering there?  

I'm wondering now if this is even possible or if the architecture for ckeditor requires one to manually select text and then invoke a plugin button to apply the formatting?

Any help will be appreciated!  Thanks in advance!