[Lazarus] The future of desktop

Mark Morgan Lloyd markMLl.lazarus at telemetry.co.uk
Fri Nov 29 11:55:43 CET 2013

Michael Schnell wrote:
> On 11/28/2013 04:39 PM, Michael Van Canneyt wrote:
>> These days it is very easy to make a very responsive web gui.
> "Responsiveness" (the program reacts to user input) is not the problem I 
> meant to describe but the ability of the program to issue "state" 
> messages spontaneously.
> This is hampered by the missing symmetry of the http protocol: The 
> client needs to poll for such "reverse" messages.

It appears that around 50% of our external network traffic is caused by 
a colleague who leaves a significant number of browser windows open each 
with Javascript which periodically polls for server-side updates.

Almost anything is better than getting tarred with that brush.

> This can partly be improved by techniques like "comet" that leave a http 
> protocol open in a somewhat "non-standard" way. But AFAIK, this does 
> result in certain problems.

That goes back to some of the earliest Netscape versions, IIRC it was 
originally used to update images periodically. While attractive, this 
sort of thing can turn into a nightmare if the browser on an end user's 
system leaks memory until an entire page (i.e. not just part of the DOM 
describing the page) is forcibly reloaded- BTDT.

Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]

More information about the Lazarus mailing list