[Lazarus] New version of WebDesign available

[Michael Van Canneyt]

On Wed, 17 Mar 2010, Michael Schnell wrote:

> On 03/15/2010 08:56 PM, Joost van der Sluis wrote:
>>> Another example (avoiding any hardware binding) would be a simple http
>>> chat cgi.
>>>
>> Not without polling
>>
>>
>
> I'm not sure what you mean by "polling" here.
>
> Of course a chat CGI (and the other examples I mentioned) do need
> polling for remote updates of the web page by Java script on the Browser
> site to avoid HTTP timeout. To avoid unnecessary communication,
> AJAX/Comet can be used to create "hanging" HTTP requests that only are
> answered by the CGI program when an update is available or before a
> timeout hits.
>
> OTOH with the standard CGI paradigm, with each HTTP communication the
> CGI program starts and finishes. So the CGI program does not have any
> permanent "states". Thus a "chat" would need to store the text to be
> transferred in a file or a database, creating a huge overhead.
>
> With the "persistent" CGI paradigm, the CGI program keeps living and can
> transfer the text it received from one user to the other just by
> managing the requests that come in from the web server  as byte streams.
>
> The NoGUIApplication package, I am planning, will allow for doing such
> persistent CGI applications. I feel that you could create a very viable
> enhancement for WebDesign, optionally enabling persistent CGI, using
> NoGUIApplication. So I'd be happy if you can test this, once I'm able to
> provide a working version.

If I understand your explanation correct, all this already exists since
quite some time in the fastcgi application type. See the custfcgi and 
fpfcgi unit.

Michael.