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Revision: 18755
at October 7, 2009 16:26 by manatlan


Initial Code
import os

class _FieldBase_:
    _defines=[]
    def __init__(self,*a):
        _FieldBase_._defines.append(self)

class _FieldedMetaClass_(type):
    def __init__(cls, name, bases, dct):
        super(_FieldedMetaClass_, cls).__init__(name, bases, dct)
        if name!="Form":
            fields_to_name = dict([(slot,name) for name,slot in dct.items() if isinstance(slot,_FieldBase_)])
            cls.fields = [(fields_to_name[obj],obj ) for obj in _FieldBase_._defines]
            _FieldBase_._defines=[] # reset list !!!

class Form (object):
    __metaclass__ = _FieldedMetaClass_

    def __repr__(self):
        l=["Form '%s'"%self.__class__.__name__]
        l+=["* %-10s : %s"%(f,t.__class__.__name__) for f,t in self.fields]
        return os.linesep.join(l)

class FieldInt(_FieldBase_):
    def __init__(self,*a):
        _FieldBase_.__init__(self,a)

class FieldString(_FieldBase_):
    def __init__(self,*a):
        _FieldBase_.__init__(self,a)

class Form1(Form):
    name     = FieldString(1)
    surname  = FieldString(2)
    age      = FieldInt(3)

class Form2(Form):
    nb      = FieldInt(1)
    title   = FieldString(2)

print Form1()
print Form2()

Initial URL


Initial Description
Like Django.models, GAE.db.model or SqlAlchemy definitions

Initial Title
Create class definitions of properties (typed and ordered) with metaclass

Initial Tags
python

Initial Language
Python