CustomerCentrix

For some upcoming new improvements to LearnCentrix, I have been analyzing javascript widgets and tools. I am always interested in new technology, currently such things as AJAX, JSON and the newest techniques for CSS and DHTML. The specific issues that we need to resolve in the next few months are:

Asynchronous loading of an html/javascript tree - we currently use a tree component to load a course, which is like an outline of web pages and other learning objects. This tree typically contains a couple hundred items, but occasionally it has 300-500 or more We are expanding on how this works, so it must accommodate potentially many thousands of items. Since the response time is currently pretty slow on the initial load when you get above 300 or so items, we need to move to a model where only the nodes closest to the root are loaded initially and the rest are loaded as needed (when requested by the user).

Cross browser support is not a requirement, but it seems silly to replace what we have and ignore this because it has been a continual request to support Mac and other browsers.

Drag and drop is another nice-to-have, but since it also narrows the choices quite a bit, it isn't really a high priority. It would be very nice to make this available for course developers to rearrange items but also quite a bit of programming. So, we'll keep this at the bottom of the list as something possible for later.

Improved UI is also a nice-to-have and also somewhat subjective. It would be great to have users look at the changes when done and say "wow, that is really cool". There is definitely sales and pr value to any look and feel improvement. On the other hand, most of these kinds of widgets already do a reasonably good job of emulating a windows tree control.

Lastly, we use several other widgets that could also use some updating, particularly for the cross platform needs. A package of controls, all from the same person or organization with similar interfaces, that has a drop down menu, tabbed windows, rich text editor, calendar and such would be ideal.

Currently, we are using a customized and older version of xtree from WebFX. They also have an asynchronous version called xloadtree which would satisfy the basic requirement of incremental loading. This site is pretty clearly a guy or two who have other priorities, since the latest news is over a year old and the most recent changes to the tree controls are a couple of years old. Seems like they work ok in Firefox and IE, but I wouldn't expect much more than that.

Dojo the browser toolkit looks interesting. It has a functional, cross-platform tree control and although fairly new, appears to be fairly well supported. Looks like some of the people/project is related to JotSpot which I have read some good things about. No drag and drop that I can tell. This one might be worth coming back to if we can't find a better alternative.

One of the best tree implementations that I have found is dhtmlxTree from Scand. Although it isn't free, it is inexpensive for use in commercial products. The drag and drop seems to work well, and it has "dynamical" loading, which looks to be incremental loading on demand as required. Also, it includes some performance discussion in the documentation that addresses our concerns.

The other widget set, Zimbra AJAX Toolkit (AjaxTK), looks interesting and comes as part of an email package. It also has drag and drop and lots of other widgets that could possibly replace or improve on what we currently have. This one is a little cumbersome to get started with because it is packaged with the email stuff, but I think will be worth the effort to dig into it.

Lastly, here are a few links to related tools or references.
      RICO project
      JSON-RPC-Java
      RIALTO project