Source Code for Module advene.model.cam.relation

 1  from advene.model.cam.consts import CAM_TYPE, CAMSYS_TYPE 
 2  from advene.model.cam.element import CamElementMixin 
 3  from advene.model.cam.exceptions import SemanticError 
 4  from advene.model.cam.group import CamGroupMixin 
 5  import advene.model.cam.util.bookkeeping as bk 
 6  from advene.model.core.relation import Relation as CoreRelation 
 7  from advene.model.core.element import TAG 
 8   
 9 -class Relation(CamGroupMixin, CoreRelation, CamElementMixin): 
10   
11      @classmethod 
12 -    def instantiate(cls, *args): 
13          r = super(Relation, cls).instantiate(*args) 
14          r._self_connect("modified-items", bk.update_element) 
15          return r 
16   
17 -    def __iter__(self): 
18          # necessary to override CamGroupMixin __iter__ 
19          return CoreRelation.__iter__(self) 
20   
21 -    def set_meta(self, key, value, val_is_idref=False): 
22          if key == CAM_TYPE: 
23              advene_type = getattr(value, "ADVENE_TYPE", None) 
24              if advene_type: 
25                  if advene_type is not TAG \ 
26                  or value.get_meta(CAMSYS_TYPE, None) != "relation-type": 
27                      raise SemanticError("not a relation type") 
28              else: 
29                  if not val_is_idref: 
30                      raise SemanticError("not a relation type") 
31   
32              old_type = self.get_meta(key, None) 
33              owner = self._owner 
34              if old_type: 
35                  old_type = owner.get(old_type, old_type) # get element if we can 
36                  owner._dissociate_tag_nowarn(self, old_type) 
37              owner._associate_tag_nowarn(self, value) 
38   
39          return super(Relation, self).set_meta(key, value, val_is_idref) 
40   
41 -    def del_meta(self, key): 
42          if key == CAM_TYPE: 
43              # TODO raise a user-warning, this is not good practice 
44              old_type = self.get_meta(key, None) 
45              if old_type: 
46                  self._owner._dissociate_tag_nowarn(self, old_type) 
47          return super(Relation, self).del_meta(key) 
48   
49  Relation.make_metadata_property(CAM_TYPE, "type", default=None, doc=""" 
50  The type of this relation, created with Package.create_relation_type. 
51  """) 
52