[wsrp-wsia][#82] What is the need of previousMode?

[Carsten Leue <CLEUE@de.ibm.com>]

I would like to open the discussion on item #82 in the issues list: What is
the need of previousMode?

UseCase:
A remote entity is requested to render its content in a specific mode, e.g.
the edit mode. It wants to embed a link in its markup that sends it out of
the current mode in the previous mode, like e.g. a cancel button in the
edit mode. The entity cannot hardcode the new destination mode as the
desired behaviour would be to go back to the mode that was active before
the switch to edit mode. The entity cannot remember the previous mode
itself because the mode is consumer side information.

I could imagine two options to enable such a behaviour.

Option1:
The consumer sends the last mode before a mode switch with each request to
the entity (as it does now in the spec). The entity can then use this mode
to encode "exit-from-this-mode" links. If there was no previous mode the
consumer sends the VIEW mode as a default.

Option2:
In addition to existing modes (VIEW, EDIT, etc) we define a BACK mode as a
predefined constant. The consumer would never use this constant as a mode
to be passed to the entity during rendering. However the entity could use
this constant to encode links that should switch the mode to the last mode
in the change history. The consumer would be required to keep such a
history or default to VIEW mode if either there is no history available or
there is no previous mode.

Best regards
Carsten


Entry from the issues list:

82    Unassigned  interface   Minor Technical   Sasha Aickin
What is the need of previousMode?
                              Date Added: 10-Sep-2002
                              Document Section: Interfaces/6.1
                              Description:      I share Alejandro's
question about the previousMode argument to getMarkup.  Also, what does
previousMode mean exactly?  If for example the user last logged in a week
ago, is the portal expected to remember the modes of every entity?  Is the
mode tracking keyed on a portal/portlet/entity basis (and thus shared among
many users), a portal/portlet/entity/user basis (and thus shared among one
user's several sessions) or on a portal/portlet/entity/user/session basis?
In my mind, this argument seems like unnecessary complexity without a clear
use case.

Best regards
Carsten Leue

-------
Dr. Carsten Leue
Dept.8288, IBM Laboratory Böblingen , Germany
Tel.: +49-7031-16-4603, Fax: +49-7031-16-4401