pli/pattern/proxy/utils.py

   1 #=======================================================================
   2
   3 __version__ = '''0.0.04'''
   4 __sub_version__ = '''20040911234403'''
   5 __copyright__ = '''(c) Alex A. Naanou 2003'''
   6
   7
   8 #-----------------------------------------------------------------------
   9
  10 import types
  11 import new
  12 import sys
  13
  14
  15 #-----------------------------------------------------------------------
  16 #----------------------------------------createmethodwrappersinobject---
  17 ##!!! REVISE (rewrite or remove) !!!##
  18 def createmethodwrappersinobject(source_obj, method_list, wrapper, target_obj):
  19         '''
  20         this will attach methods mentioned in method_list to the target object
  21         that will wrap methods of the source object.
  22
  23         WARNING: this will render the target object unpicklable...
  24         NOTE: this can be used for classes...
  25         '''
  26         for meth in method_list:
  27                 if hasattr(source_obj, meth):
  28                         setattr(target_obj, meth, wrapper(getattr(source_dict, meth)))
  29         return target_obj
  30
  31
  32 #------------------------------------------------createmethodwrappers---
  33 ##!!! REVISE (rewrite or remove) !!!##
  34 def createmethodwrappers(source_dict, method_list, wrapper, target_dict=None):
  35         '''
  36         this will wrap methods mentioned in method_list from the source dict and
  37         will return a dict containing the wrappers (will update and return target_dict
  38         if given).
  39         '''
  40         if target_dict != None:
  41                 res = target_dict
  42         else:
  43                 res = {}
  44         for meth in method_list:
  45                 if meth in source_dict:
  46                         res[meth] = wrapper(source_dict[meth])
  47         return res
  48
  49
  50
  51 #-----------------------------------------------------------------------
  52 #--------------------------------------------------genericproxymethod---
  53 def proxymethod(method_name, source_attr, depth=1):
  54         '''
  55         this will create a proxy to the method name in the containing namespace.
  56
  57         NOTE: this will add the method_name to the containing namespace.
  58         NOTE: source_attr is to be used as the attr name referencing the source object.
  59         '''
  60         # text of the new function....
  61         txt = '''\
  62 def %(method_name)s(self, *p, **n):
  63         """
  64         this is the proxy to %(method_name)s method.
  65         """
  66         return self.%(source_attr)s.%(method_name)s(*p, **n)
  67 proxy = %(method_name)s'''
  68         # execute the above code...
  69         exec (txt % {'method_name': method_name, 'source_attr': source_attr})
  70         # update the NS...
  71         sys._getframe(depth).f_locals[method_name] = proxy
  72
  73
  74 #--------------------------------------------------------proxymethods---
  75 def proxymethods(names, source_attr):
  76         '''
  77         this will generate a direct proxy for each name.
  78         '''
  79         for name in names:
  80                 proxymethod(name, source_attr, depth=2)
  81
  82
  83
  84 #-----------------------------------------------------------------------
  85 #------------------------------------------------------swapmethodself---
  86 def swapmethodself(meth, wrapper, use_wrapper_as_class=True):
  87         '''
  88         '''
  89         return new.instancemethod(meth.im_func,
  90                                                                 wrapper,
  91                                                                 use_wrapper_as_class and \
  92                                                                                 wrapper or meth.im_class)
  93
  94
  95 #------------------------------------------------------wrapmethodself---
  96 def wrapmethodself(meth, wrapper, use_wrapper_as_class=True):
  97         '''
  98         '''
  99         return new.instancemethod(meth.im_func,
 100                                                                 wrapper(meth.im_self),
 101                                                                 use_wrapper_as_class and \
 102                                                                                 wrapper or meth.im_class)
 103
 104
 105
 106 #=======================================================================
 107 #                                            vim:set ts=4 sw=4 nowrap :