[p2-dev] need some help with feature un-installation process.

[Pradeep Fernando <pradeepfn@xxxxxxxxx>]

hi devs,

I am relatively new to Equinox OSGI & P2 provisioning.  My primary
reference is OSGI & Equinox book [1] . In my current code, I have
features that wraps server side functionality & client side
functionality. In order to create further abstraction I wrap these
features in another composite feature using.

<include/> directive in the feature xml.
The end result is ;

Composite_feature -- ---  server feature
                                |
                                 '-- ui feature

But with this organization I'm finding it hard to implement a
un-installation, where i can select any of the UI feature &  click
un-install.
In my current code the p2-planner gives a severity status 4. which
says there are other features that depends on the UI feature. This is
acceptable since the
composite feature needs UI feature to function properly.

The current solution i can think of is,

to un-install the UI feature,
           1. un-install the composite feature first
           2. install the other features that remained in the
composite feature programatically (In this case Server feature).

I can do this by using some feature tagging as stated in the equinox book.

Is this the proper way to do this ?.
Is there a better way provided by the P2 provisioning framework?
Is there anything wrong with my composite feature approach. (I follow
composite feature approach, so i can give one feature to the end user
rather than providing 2,3 features. )

Your feedback is much appreciated.


[1] http://www.amazon.com/OSGi-Equinox-Creating-Modular-Systems/dp/0321585712

-- 
Pradeep Fernando.