Re: [Bodington-developers] alias_entries - Suggested change to constraints.

[Matthew B. <mat...@ou...>]

Jon Maber wrote:
> Matthew Buckett wrote:
>> Could you superclass  Alias and AliasEntry to MultiAlias and 
>> MultiAliasEntry. These classes don't enforce the restriction of only 
>> allowing one alias per user. This way any code that deals with aliases 
>> will never get more than one entry per user and programmer won't have 
>> to change how they thing about aliases but functionality in certian 
>> places can be alter to work with MultAlias(Entry)
> An ingenious idea!

Thanks.

> It might also help address Peter's comment.
> This way there is a mechanism that enforces a distinction between the 
> two types of alias. Functionality that takes an alias value and finds a 
> user can ignore the distinction but functionality that takes a user and 
> looks up an alias entry to label him/her can present a list of optional 
> alias types that excludes the MultiAlias objects, but depending on its 
> purpose it can choose to return and display the list of alias entries 
> per user.  So, taking the MCQ test as an example it could be made 
> possible to ask for 'student_id' to be printed in the table but disallow 
> 'old_student_ids' because the former would be an AliasEntry and the 
> latter a MultiAliasEntry. On the other hand the user directory tool 
> could happily allow a member of staff to find a student by typing in an 
> 'old_student_ids' value.

The bit I'm not sure about is if MultAlias(Entry) will truely be able to 
be the parent class of Alias(Entry) due to the database design.

> The main purpose of the MultiAlias would be for administrative data and 
> wouldn't necessarily contain aliases of interest to staff and student.
> 
> The other advantage of subclassing is that we can implement it at Leeds 
> with Bodington 2.6 as an add-in without changing the existing code or 
> the definitions of the existing database tables.

Hopefully.

> Give that man a pay rise!

  :-)

-- 
  -- Matthew Buckett, VLE Developer
  -- Learning Technologies Group, Oxford University Computing Services
  -- Tel: +44 (0)1865 283660 http://www.oucs.ox.ac.uk/ltg/