Forum OpenACS Development: ajax based chat as xowiki page

Hi folks, i have checked into cvs HEAD a small extention to xowiki, that implements the client and server side of a ajax based chat system. This is implemented via the programmable xowiki::Object class. i have implemented the system from scratch, since, i was just interested in getting some experience with ajax, but - aside from javascript quirks - this worked quite nicely. Here you can see an xowiki page with categories and the xowiki chat embedded.
http://media.wu-wien.ac.at/download/xowiki-doc/ajax-chat.png
Login into the chat happens simply by loading the xowiki page. I have tested with safari and firefox.

in order to try the xowiki ajax chat, load the following file from the browser and you will create in that xowiki package instance a page named en:ajax-chat.

http://.../xowiki/admin/samples/ajax-chat

I have tried to make the display as flicker-free as possible, this works quite well. every chat is identified by a chat-id, which could be in general a package_id, community-id, or whatever. the chat-id is configured in the wiki-page and is set currently to 22. There are some more limitations: Currently, only one chat is allowed per browser. if the login times out, the background process is not able to login automatically. so far, the chat is volatile, that is, the messages are not logged to the database or to some log file, but that's not complicated at all.

The length of the code in the content-part (you will see this by editing the page) can and will be reduced, such that only the configuration stays there. i am not sure yet, how much of this should go to the library...

the "content-part" is currently 25 lines (including the form, url-definitions, etc.) and should be reduced to 10 or so. i am not sure, whether the .js libraries your are mentioning will help with that.

the bigger question is, how many XMLHttpRequests for one browser we want to have more or less in parallel, how to address the multiple instances of one app in browser windows/tabs (names of dom elements), how to bundle/multiplex multiple inquirers in a single HTTPrequests and answer sets. In other words, would not be optimal, if for every ajax application instance, separate XMLHttpRequests whould be created, all of these polling the server for updates. one poll should provide data for all inquirers. registering callbacks in js look like a good idea...

The situation might be different in your situation, i would assume, that once the "cinematic effects" are done (whatever these are) no more requests are needed.

Hello Hamilton,

I've tried out your AjaxHelper package and find it is a very useful addition for OpenACS. But I am afraid it produces too much overhead.
If I have for example a page where I only want to use that bubblecallout feature - which should be a very trivial one - the loading time of the page increases from approximately 1 second to over 6 seconds!
Perhaps one can reduce the amount of javascript files that are loaded by default to an absolute minimum.

Greetings,
-Rainer

Oh and have you seen the demo ?
It's on a temporary server

http://sgsandbox.com:8002/xowiki/demo

username : mailto:demo@solutiongrove.com
password : demo

I seriously hope this develops into an alternative to the way we handle portlets and portals at the moment. I'm missing though a "save" function :).

Furthermore it does not work on Safari.

there is a new version of my ajax based chat package checked in cvs HEAD, most of the mentioned shortcomings are removed. Every chat client has a session-id now, a single user logging in from two browsers or two browser frames gets now a different id, so the user can to himself - not, that this is important, but should work anyhow. the chat works now with IE as well.

if you edit the page en:ajax-chat, you see that its contents are reduced now to

	proc content {} {
	  ::xowiki::Chat login -chat_id 22
	}

By removing the chat_id, per default the package_id is used as chat_id (this means one chatroom per package instance). If it is left as it is, no matter from which instance of xowiki this is coming, the chat connects to a chatroom with chat_id 22.