Thursday, August 21, 2008

Sahi - Latest developments

Copy of post on forum:

I had not been active on the Sahi forums ( for sometime. Thanks a ton to StringyLow, tinchie8, lepierrot, pankaj.nith and others for keeping this forum active, and replying to posts.

Meanwhile I have been working on a version of Sahi which attacks one of the basic problems with Sahi.
Scopes of variables, scheduler and normal functions and the the way steps are queued and executed and the way their integrity needs to be maintained across page loads.

The problem had been that the scripts (after parsing) were executed on the browser itself, and when a page unloads, the state of the script's execution needed to be persisted on the proxy and then resurrected when the next page loaded. While this allowed the ease of using javascript for scripting, when scripts became bigger, the browsers and the proxy had to do a lot more persisting and resurrecting.

As the logical next step, I wanted to move this script execution to the proxy. I now use Rhino, an excellent javascript engine, to execute the scripts on the proxy. Only steps that need to be executed on the browser are sent to the browser. Javascript can still be used for Sahi scripting. Even though the script still is parsed, it is much simpler to understand script execution than it was before. Rhino also comes with a debugger which can prove useful to Sahi script debugging.

The version is slated to be released soon. I am looking for volunteers to test and give me feedback about the new version. If you have existing scripts, the scripts may need to be modified a little to make it work with the new version.
If you are interested, please post back or email me at narayan at

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