[Lazarus] Converting Pascal Client/Server application into Web Client?

[Michael Schnell]

  On 10/01/2010 01:25 PM, Michael Van Canneyt wrote:
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> Not sure what you mean by that.
Sorry, but my old brain does not come up with the correct name of the 
method (which I do know, though).  :(

Here a (FastCGI) polling access is generated by the client java script, 
and the CGI-Application does not respond so it hangs. The server 
responds immediately to the still hanging request whenever an 
asynchronous "server-event" arises. The client java script gets this 
response and acts appropriately. There are some precautions that the 
requests does not hang so long that the WebServer times out and kills it.

This is necessary to overcome the asymmetry of the http protocol.

IMHO "Server-Events" are necessary to design a CGI program with some 
complexity.

Moreover "server-Internal-Events" like from Timers, serial or "direct" 
TCP/IP communication, thread-notification, ... are very desirable and 
should be able to fire "server-events" towards the client.

-Michael