Re: [Phprojekt-devel] Access, cache and multi users

[Johann-Peter H. <har...@ma...>]

Hi,

Gustavo Solt schrieb:
> Point b)
>   - If the User A was IN the TODO #1, and try to change something, he
> will get a message "The item don't exist" (for him, don't exists anymore)

That's a misleading error message, it should be "You are not allowed to
do this!" ;-) (better: "Missing access rights for this item")

> 
> Point c)
>   - The User B, since is still in the item, get a front message that the
> TODO was changed by the admin, but when he want to see the changes,
> the access still say "User A and User B", since the access is cached in
> the server.
> 
> That is more or less not so important, since is an strange case,
> but what about the same on a project?
> 
> If the User A is removed from a project, then he will have some errors
> when try to access to it (an Exception since the "node" don't exists).

This should be the same error message as above. Any access control error
should result in a clear error message documenting the user does not
have access rights to the current item (anymore).

> If the User A is ADDED to one project, the user will receive a front
> message, but he DON'T will see the new project, since the access for all
> the projects is already cached from the server for him.
> The solution is "logout, and login again".
> 
> These cases, are not so commons, but can happen and we should offer some
> solutions for that.

For me it looks like a wrong caching strategy. The caching should work
with active invalidation, i.e. if an item changes on the server, every
cache for it should be cleared - even client-side caches.

The Zend_Cache provides tagging and the clean method for this purpose.


Greetings,
Johann