On Monday 09 June 2008 03:56:20 Michael Bayer wrote: > On Jun 8, 2008, at 5:02 AM, [EMAIL PROTECTED] wrote: > > hi > > i'm trying to make a metainfo extractor off some relation > > attribute. by metainfo i mean the klas and attr-name of this and > > of the other side of the relation-attribute, or of the parent or > > child of the relation regardless the start point. > > > > e.g. possible usage and testing invariants is like: > > a = about_relation( someklas.someproperty) > > print a.name, a.klas, 'is_parent:', a.is_parent > > assert a.thisside == a > > b = a.otherside > > print b.name, b.klas, 'is_parent:', b.is_parent > > assert a.otherside.otherside == a > > if a.is_parent: > > assert a.child is a.otherside > > assert a.parent is a.thisside > > else: > > assert a.parent is a.otherside > > assert a.child is a.thisside > > e.g. if Parent.kids / Kid.parent are 1:many: > > print about_relation( Parent.kids).otherside.name -> 'mama' > > print about_relation( Parent.kids).otherside.klas -> 'Kid' > > print about_relation( Parent.kids).child.klas -> 'Kid' > > print about_relation( Kid.parent).child.klas -> 'Kid' > > print about_relation( Kid.parent).parent.klas -> 'Parent' > > print about_relation( Kid.parent).otherside.name -> 'kids' > > def about_relation(descriptor): > prop = descriptor.property > return { > 'child':{'name': prop.key, 'klas': prop.mapper.class_} > 'parent':{'klas':prop.parent.class_} > } > > I don't understand what "is_parent" means (nor 'thissside' and > 'otherside'). every relation has a "parent" and "child". given the descriptor Kid.parent, it is considered "thisside", and the other end descriptor (Parent.kids) is "otherside"; is_parent is which role the particular descriptor is, from a 1-to-many terminology. maybe i use wrong naming ...
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