Hi,
Le 26 juil. 07 à 08:55, Bill Moseley a écrit :
There's a recent article titled "Never Use a Warning When you Mean
Undo" at http://alistapart.com/articles/neveruseawarning.
I'm wondering about the implementation.
I read that too. Interesting, but from what I see undo is not so easy
to implement.
One option is to create actions for every possible undo operation.
That would mean that each undo operation would generate a specific
link, including request parameters to identify the item that needed to
be, well, undone.
Another possibility would be to generate the code for the undo action
and place it in the session so that there's just an /undo link. /undo
fetches the code and evals/executes it. The /undo link would only be
available for a single request after displaying the undo link.
I like more the idea of a generic undo request. This could be part of
a plugin providing this action and the necessary infrastructure to
implement the "un-doing" of the action.
This plugin could implement a simple version of the classic Memento
pattern (http://en.wikipedia.org/wiki/Memento_pattern)
Then you could declare undoable actions like this:
sub delete : Local Undoable {
my ($self, $c) = @_;
...
$c->save_undo( $object );
}
# Actual undo action
sub undo_delete : Private {
my ($self, $c, $restored_object) = @_;
...
# recreate object from $restored_object
}
The generic undo action would then forward to the above declared
undo_delete action, restoring the saved object.
This would even perhaps allow multi-level undo.
If the undo link is part of the server response the back button might
lead to a stale undo link. If that's a problem I suppose could do an
AJAX request to fetch the link to prevent it showing up if using the
back button.
Could be in the plugin too, I guess.
--
Matthieu Codron
[EMAIL PROTECTED]
_______________________________________________
List: Catalyst@lists.rawmode.org
Listinfo: http://lists.rawmode.org/mailman/listinfo/catalyst
Searchable archive: http://www.mail-archive.com/catalyst@lists.rawmode.org/
Dev site: http://dev.catalyst.perl.org/
