[Gambas-user] Web application development

[Rob]

On Monday 16 October 2006 16:21, Daniel Campos wrote:
> In that sense people interested in "gb.ajax" (I hope somebody
> finds a better name), should check the Comet programming
> technology:
> http://en.wikipedia.org/wiki/Comet_%28programming%29 , that
> surely will provide big ideas for that component.

I had actually expected to make use of the Comet technique, but I 
don't think it's safe to assume browsers will always behave 
nicely (i.e. not break the connection) and I certainly don't 
want to put any requirements on the server except for having 
Gambas installed as a CGI interpreter (i.e. no special 
middleware or proxy.)  So state still needs to be maintained 
between requests, and cleaned out periodically.  

But at its simplest, Comet can be implemented as "open a 
connection, when the connection returns something, handle it, 
and when the connection closes, immediately reopen it."  You 
have a message queue on the browser side that transmits requests 
over that one persistent connection and receives drawing and 
timer events from the server side.  I would also want to have 
some kind of ping or heartbeat functionality, because if there's 
one thing I've learned in the last year and a half of being up 
to my elbows in Ajax, it's that TCP connections are not quite as 
reliable in the real world as they are in the spec.

I agree that "gb.ajax" or "gb.web.ajax" would suck as a name, but 
you can't deny its buzzword compliance ;)  If someone does 
suggest another name, I hope that it isn't just "gb.comet" 
or "gb.SomeOtherToolkit" or "gb.SomeNewMeaninglessName".  I'd 
sooner call it "gb.form.web" (or "gb.web.form"), if that won't 
raise people's expectations too high.

> A person here was able to run parts of the Squeak environment
> (Smalltalk) directly in a browser. Comet techniques also
> allows to draw directly on a client web canvas (Firefox and
> Safari/Webkit have one, and there's an emulation for IE), and
> even work sending graphical events from the client to the
> server and sending a server-client reply using Javascript
> injection.

I certainly intend to support the Firefox canvas in some way, 
though I don't know whether my graphics-fu and/or the Firefox 
canvas itself is good enough to implement most of what Gambas' 
DrawingArea does.

In answer to Benoit's earlier post, I see your point about having 
different controls for the web vs. gb.qt/gb.gtk, but the whole 
point of my "gb.ajax" concept is to allow novice web programmers 
to design their forms in the Gambas IDE and deploy them to the 
web just by moving the checkmark from "gb.qt" to "gb.ajax" in 
project properties.  It will make for some pretty crappy forms 
being deployed, but then, look at the hideous things people have 
done with Scriptaculous.  I don't think anyone would say they'd 
rather that it hadn't been written.

It's a lofty goal, but why have goals that aren't?

Rob