At 16:54 17/09/99 , Damian Morton wrote:
I guess my experience is with sites that tend to get up to a million of hits a day. In this case, the DOM is slowly changing wrt to the queries. However, even in a lower demand situation; a situation in which the changes outstrip the demand, the dataflow scheme still has advantages. You are still only rendering that which needs to be rendered, which is generally a good thing. You can also get more sophisticated about your dataflow, mixing a feedforward with a demand-driven scheme based of usage statistics. If a given tree is demanded more frequently than it changes, then it is rendered as its inputs change. If the tree is changed more frequently than it is demanded, then it should be rendered on demand. In this way the scheme is adaptive with respect to both demand and design. I do think, however, that in most places, in most websites, the parts that change as frequently as (or more frequently than) they are demanded will be small in number and scope. About the only things I can think of that might fall in this category are time-based elements, and non-deterministic elements.
In Zope, the inputs to a rendered document depend on the acquisition path taken, and there is an unlimited number of combinations. I don't think that a dataflow scheme is therefore applicable to Zope. -- Martijn Pieters, Web Developer | Antraciet http://www.antraciet.nl | Tel: +31-35-7502100 Fax: +31-35-7502111 | mailto:mj@antraciet.nl http://www.antraciet.nl/~mj | PGP: http://wwwkeys.nl.pgp.net:11371/pks/lookup?op=get&search=0xA8A32149 ------------------------------------------