Package gavo :: Package base :: Module parsecontext :: Class ReferenceAttribute

Class ReferenceAttribute

          object --+        
                   |        
attrdef.AttributeDef --+    
                       |    
 attrdef.AtomicAttribute --+
                           |
                          ReferenceAttribute

Known Subclasses:

An attribute keeping a reference to some other structure

This is a bit messy since the value referred to keeps its original parent, so self.attr.parent!=self for these attributes. This is ok for many applications, but it will certainly not work for, e.g. tables (roughly, it's always trouble when an attribute value's implementation refers to self.parent; this is particularly true for structures having an RDAttribute).

So, before adding a reference attribute, think first whether it wouldn't be wiser to have the real thing and use original to copy things over.

Instance Methods

__init__(self, name='ref', default=<Undefined>, description='Uncodumented', forceType=None, **kwargs)
x.__init__(...) initializes x; see help(type(x)) for signature source code

create(self, structure, ctx, name)

source code

feed(self, ctx, instance, literal)

source code

unparse(self, value)
returns a typed python value for the string representation value.

source code

Inherited from attrdef.AtomicAttribute: feedObject, getCopy, makeUserDoc, parse

Inherited from attrdef.AttributeDef: doCallbacks, iterParentMethods

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__, __subclasshook__

Class Variables
	typeDesc_ = `'id reference'`

Properties
Inherited from `object`: `__class__`

Method Details

init(self, name=`'ref'`, default=<Undefined>, description=`'Uncodumented'`, forceType=None, **kwargs)
(Constructor)

source code

x.__init__(...) initializes x; see help(type(x)) for signature

Overrides: object.__init__: (inherited documentation)

feed(self, ctx, instance, literal)

source code

Overrides: attrdef.AttributeDef.feed

unparse(self, value)

source code

returns a typed python value for the string representation value.

value can be expected to be a unicode string.

Overrides: attrdef.AtomicAttribute.unparse: (inherited documentation)

Class ReferenceAttribute

__init__(self, name='ref', default=<Undefined>, description='Uncodumented', forceType=None, **kwargs) (Constructor)

feed(self, ctx, instance, literal)

unparse(self, value)

init(self, name=`'ref'`, default=<Undefined>, description=`'Uncodumented'`, forceType=None, **kwargs)
(Constructor)