Stateful pages have been giving me headaches ever since they were introduced in
1.4/1.5 and I'm
proposing that we remove them.
Stateful pages not only complicate the Click codebase but conceptually they are
difficult to
understand compared to a stateless page which starts every request with a clean
slate.
I also think they are too easy to use (and abuse). Consider this scenario: you
have a table with
sort and paging state that you want to store while the user navigates between
pages. The obvious
answer is to make the page stateful. However, not only is the table sort and
paging state stored,
but the entire Page including its model Map, control List, i18n messages and
every Page variable is
stored as well. And all you really wanted was to store 4 objects in the session.
I propose we deprecate the method Page.setStateful for 2.3.0-M1. Sadly there
isn't any upgrade path
for existing code bases. Stateful pages simply have to be converted to
stateless Pages and the view
state will have to be managed by the users or custom Controls that manage their
state themselves.
Any objections? ;)
This feature is since ages in there, and already just too many
applications made use of it :(.
(Had myself too converted some Wicket apps to Click)
I understand that it complicates the Click codebase, and it also has
some bad impact on performance, but it is a very useful feature
especially for RIA apps and for quick prototyping - people just love it
(and yes, they abuse it too, but they get the job done very fast this way).
Would it be possible at least to have this feature as an external
project though (e.g. by an extended functionality of PageInterceptor or
some other way) ?
Adrian.
