[mapguide-users] Silverlight/Moonlight Viewer

[Kenneth Skovhede, GEOGRAF A/S]

Yes, the ActiveX viewer format is called DWF, and it is a format 
Microsoft intends to support
in the next version of Windows (called XPS I think?). Unfortunately, to 
use it would require some
form of deployment to the client machine, until it is standard on all 
machines.

With Silverlight, this poses problems, as it runs in a sandbox, and thus 
cannot access or install
the required component. It might be possible to develop a completely 
managed DWF library,
and that would work, but that would require some heavy work.

And yes, you are spot on with your observations on tradeoffs :).

Regards, Kenneth Skovhede, GEOGRAF A/S



Carl Jokl skrev:
> Perhaps I am missing something here but my understanding of the latest
> versions of MapGuide was that it still supports the ActiveX based viewer as
> well as the new AJAX viewer, is this correct?
>
> If this is correct then I would ask the question of how the ActiveX viewer
> works when interacting with the MapGuide Enterprise / Open Source framework? 
>
> Looking at things from a high level I thought this would just be a matter of
> creating a replacement viewer for the ActiveX component which behaved and
> operated like the ActiveX viewer but was implemented using a different
> technology.
>
> I don't mean to imply that this is a trivial task by any means just that if
> the ActiveX viewer still works then there ought to be scope for having
> another component plug into the functionality that powers the ActiveX
> control. 
>
> There is a tradeoff to be met here. The Ajax component is good and has
> advantages when it comes to compatibility and not requiring any pluggin to
> work but on the other hand it increaces the bandwith usage and can be
> sluggish when bandwidth gets constrained. The problem also pushes back to a
> fairly long standing argument of the virtues of Thick Client vs. Thin
> Client. The more work you can push onto the client the less work the server
> has to do. This can help the application scale better / handle higher
> volumes of users. The flip side is that it makes deployment on the client
> more complicated and may introduce client compatibility issues. 
>
> For these reasons I don't think that the benefit of having both thick(er)
> client and thin(er) versions of the viewer can be disregarded. I think some
> kind of viewer which uses less bandwith and renders on the client side
> whether it be the existing ActiveX control or something else which does the
> same thing is important to have. This provides and important alternative for
> situations where the Ajax viewer performs poorly.
>