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Categories and Advanced Search

Question asked by sacco on Feb 19, 2007
Latest reply on Apr 4, 2007 by alexandra
Hi

I've been looking at the implementation of Categories and, as far as I understand, the general classification with the user-visible categories is achieved by adding an aspect to a content object with a single  multi-valued property which can contain references to nodes in a space of categories (rather like using URLs to identify namespaces, I suppose).

Then there is (according to the Wiki, although it doesn't seem to match the code entirely) a clever trick with indexing which allows one to search over child categories using paths (similar to XPaths) in the index
although I haven't yet found any trace in the Web Client of the special "member" QName mentioned here:

http://wiki.alfresco.com/wiki/Search#Category_Queries

OK so far? 
Although I'm not sure what is the point of exposing the top level categories uniformly with the rest:  what could it mean when a user searches for something with the category 'Regions' for instance.

I get the impression that this mechanism may also be lurking somewhere in the background for other more system-oriented categorisations, i.e. one could use the same sort of Category hierarchy stuff with another property/aspect to do something else.


However, the semantics of Advanced Search with multiple categories implemented following
http://issues.alfresco.com/browse/AWC-479
isn't quite what users might expect:  using the same notation as AWC-479, what is really required is:

+Folder +(catA1 catA2 catA3) +(catB1 catB2 catB3)

where catA?, etc. are all the subcategories that come under one top level categorisation, e.g.Regions in the bootstrap setup.

To illustrate with an example: if a user makes a search specifying the two categories 'User Manual' and 'Japanese', it is extremely unlikely that they actually want a list of results which includes both all User Manuals in the repository and all documents of whatever type in Japanese.


In any case if this really were required, it would probably be better achieved with two separate searches, whereas, as things stand, there's no easy wey to get to all the User Manuals available in Japanese.


A better approach would be to 'OR' Categories sharing a common top level "super-category", but to 'AND' the resulting disjunctions (and in the unlikely case that anybody has found a use for 'OR' across classification, this could still be achieved simply by dropping the two category hierarchys under a common root 'super-category').

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