Demonstrating extensibility for 3.0: Approve requested quantities in packs

[Josh Zamor]

Hi everyone,

Achieving extensibility in OpenLMIS through Extension Points and Extension Modules is as we all know a core aspect to our architecture.  To date we have built a good example for the basic mechanism which is available in the Example Service repository.

What's needed now is to show how a point of variance between previous releases of OpenLMIS could be solved using extensions in our new architecture.  In doing this we'll be able to highlight within the community how we can support differing country needs without forking the code-base.  The team here in Seattle has been racking our brains on what point of variance we'd like to use to demonstrate this new mechanism.  We've been looking for something that:

1. was a point of variance between v1 and v2
2. demonstrates the use of extension points & modules
3. would provide a straightforward example for implementations to follow
   

What we've chosen is the feature in version 2 that allowed for a Requisition Template to be configured in such a way that an Approver would enter Approved Quantities in Packs rather than Dispensing Units.  This feature seems to satisfy our criteria above quite well.

We'll be designing and slotting this work soon so your feedback would be appreciated:  would demonstrating how to utilize an extension point from an extension module so that an Approver would enter the Approved Quantity in their Requisition in terms of Packs rather than Dispensing Units sufficiently show how Extension Points and Modules will be used to address country variance without forking the code?

Best,

Josh