[mcclim-devel] Yet another half-baked half-finished backend

[Christophe Rhodes]

David Lichteblau <david at lichteblau.com> writes:

> Hand-written JavaScript code could fetch a description of the shapes to
> render using XMLHttpReqest, which has "XML" in its name, but can
> actually also fetch arbitrary text/plain documents.  At least on Firefox
> this approach also works for documents in the local file system, so a
> web server is not necessary initially.
>
> Interactive use is then just a matter of repeating these requests to
> wait for more events from the server or to send keyboard events back
> (but will obviously require a web server at that point).

I suppose another question is whether people think that this is
worthwhile -- I think it's fair to say that we're fairly stretched as
is; at least, I am.  (I can't in all fairness make any promises at all
about time I have to polish this at the moment, for instance.)

> (Since you mentioned lack of a web coder, see
> http://www.lichteblau.com/blubba/responsetext/test.html for a trivial
> XMLHttpRequest example that renders a text file from the same
> directory.)

My epiphany says

  Javascript error in  on line 0:
  uncaught exception: [Exception... "Not enough arguments
  [nsIXMLHttpRequest.send]" nsresult: "0x80570001
  (NS_ERROR_XPC_NOT_ENOUGH_ARGS)" location: "JS frame ::
  http://www.lichteblau.com/blubba/responsetext/test.js :: <TOP_LEVEL>
  :: line 29" data: no]

I'm afraid.  (But I get the idea, I think.)

> So the next step could be to define a textual format that describes the
> shapes to render which is as compact as possible.
>
> Made-up example for a syntax that might or might not be more compact:
>   M42R0,0,100,100
> could mean "medium operation", "the medium with ID 42", "draw a
> rectangle", "here are the coordinates".

Right.  

I suppose another way is to compile enough of the various applicable
methods that much of the responses to user interaction can be executed
on the client -- it would be insane to round-trip for stuff like
highlight-presentation, for instance.  Again, I don't have a feel for
how possible this is.

Thanks,

Christophe