Ajax Girl

I love to hear the stories behind the technology. This way you have a chance of learning from a fellow developers trials and tribulations.

Dav Glass of the YUI team was in charge of building the new Rich Text Editor that was just released, and has documented part of the journey which includes how he managed to get this puppy working on Safari 2:

My development approach was to bend Safari first. I built it to work in Safari 2 before retrofitting it back to Opera, then Firefox and lastly Internet Explorer. I figured that if I could make Safari do what I wanted, the other three would fall into place nicely. And they did. By choosing to make Safari work first I was able to make the others do things in a standard way as well. I hope that Safari will eventually catch up to its A-grade peers and add support for the things that I have “emulated”, so I took that into consideration too.

How did he hack around Safari 2?

Safari 2 is a really good browser, but it was also the most challenging browser to support with the RTE project. It lacks some serious and critical features when it comes to editing HTML content from JavaScript. I will try to explain the main hurdles that Safari presents:

Iframe Focus - One of the biggest issues was actually quite simple to solve. Safari (and Internet Explorer) has an issue with selecting text inside of an embedded iframe. If you select text within the editor’s iframe then click/focus the parent document, the selection within the iframe is lost. Clearly, this makes it rather difficult for a button click to take action on the selection (because the selection is lost when you click the button!). It also makes it difficult to use, say, a YUI Menu Control for a drop down. As I investigated this problem, I determined that if you stop the mousedown event on the button/href the selection doesn’t get lost. However, if something else (say a href in a dropdown menu) gets focus, the selection will still get lost. This leads me to the next Safari trick.

Selection Object - The selection object in Safari is very limited (to say the least). To work around its limitations, the YUI RTE caches a copy of the current selection in the _getSelection method. Then, the next time _getSelection is called I check to see if a cache existed. If the cache is there, I “rebuild” the selection and destroy the cached copy. This little trick is what lets Safari use a YUI Overlay as a menu instead of the more classic approach of a select element. It’s roundabout, but it works.

execCommand limitations - This is the mother of all hacks for Safari (and the others). My biggest problem with the native execCommand method (in all browsers) is that the browser doesn’t tell you what it applied the command to. So there is no real way to get an element reference back after running a command on a selection. The world of JavaScript editors would be so much more civilized if this would happen (hint, hint, nudge, nudge). So what I had to do was implement this feature myself. My current approach may not be the best way to do it (I have some other ideas that I am working through), but it does the job for now. The method is named _createCurrentElement and basically it runs execCommand('fontname', false, 'yui-tmp'); on the given selection (since fontname is supported on all A-Grade browsers). It will then search the document for an element with the font-family/name set to yui-tmp and replace that with a span that has other information in it (attributes about the element that we wanted to create), then it will add the new span to the this.currentElement array, so we now have element references to the elements that were just modified. At this point we can use standard DOM manipulation to change them as we see fit. In short, I’m using the iframe’s DOM to store metadata during editing as a way to enrich the communication that’s possible between the editor and the iframe.

Thanks for sharing the story.

Source: Ajaxian
Original Article: http://feeds.feedburner.com/~r/ajaxian/~3/144803652/tales-of-the-rich-text-editor-and-safari-support