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loops - Linked Objects for Organization and Processing Services
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  ($Id$)

Concepts and Relations
======================

Let's start with creating a few example concepts, putting them in a
top-level loops container and a concept manager:

  >>> from loops import Loops
  >>> loops = Loops()

  >>> from loops.concept import ConceptManager, Concept
  >>> loops['concepts'] = ConceptManager()
  >>> concepts = loops['concepts']
  >>> zope = Concept()
  >>> concepts['zope'] = zope
  >>> zope.title
  u''

  >>> zope3 = Concept(u'Zope 3')
  >>> concepts['zope3'] = zope3
  >>> zope3.title
  u'Zope 3'

Now we want to relate the second concept to the first one.

In order to do this we first have to provide a relations registry. For
testing we use a simple dummy implementation.

  >>> from cybertools.relation.interfaces import IRelationsRegistry
  >>> from cybertools.relation.registry import DummyRelationsRegistry
  >>> from zope.app.testing import ztapi
  >>> ztapi.provideUtility(IRelationsRegistry, DummyRelationsRegistry())

Now we can assign the concept c2 to c1 (using the standard ConceptRelation):
        
  >>> zope.assignConcept(zope3)

We can now ask our concepts for their related concepts:

  >>> sc1 = zope.getSubConcepts()
  >>> len(sc1)
  1
  >>> zope3 in sc1
  True
  >>> len(zope.getParentConcepts())
  0

  >>> pc2 = zope3.getParentConcepts()
  >>> len(pc2)
  1

  >>> zope in pc2
  True
  >>> len(zope3.getSubConcepts())
  0

TODO: Work with views...
        
Resources and what they have to do with Concepts
================================================

We first need a resource manager:
    
  >>> from loops.resource import ResourceManager, Document
  >>> loops['resources'] = ResourceManager()
  >>> resources = loops['resources']

A common type of resource is a Document:
      
  >>> zope_info = Document(u'Zope Info')
  >>> resources['zope_info'] = zope_info
  >>> zope_info.title
  u'Zope Info'
  >>> zope_info.body
  u''
  >>> zope_info.format
  u'text/xml'

We can associate a resource with a concept by assigning it to the concept:

  >>> zope.assignResource(zope_info)
  >>> res = zope.getResources()
  >>> list(res)
  [<loops.resource.Document ...>]

The resource also provides access to the associated concepts (or views, see
below) via the getClients() method:

  >>> conc = zope_info.getClients()
  >>> len(conc)
  1
  >>> conc[0] is zope
  True

Views: Menus, Menu Items, Listings, etc
=======================================

We first need a view manager:
    
  >>> from loops.view import ViewManager, Node
  >>> loops['views'] = ViewManager()
  >>> views = loops['views']

The view space is typically built up with nodes; a node may be a top-level
menu that may contain other nodes as menu or content items:
      
  >>> m1 = Node(u'Menu')
  >>> views['m1'] = m1
  >>> m11 = Node(u'Zope')
  >>> m1['m11'] = m11
  >>> m111 = Node(u'Zope in General')
  >>> m11['m111'] = m111
  >>> m112 = Node(u'Zope 3')
  >>> m11['m112'] = m112
  >>> m112.title
  u'Zope 3'
  >>> m112.description
  u''

We can associate a node with a concept or directly with a resource via the
view class's target attribute:

  >>> m111.target = zope_info
  >>> m111.target is zope_info
  True
  >>> m111.target = zope_info
  >>> m111.target is zope_info
  True
  >>> m111.target = zope3
  >>> m111.target is zope3
  True