wxPython/wxPython/lib/PyCrust/introspect.py

   1 """Provides a variety of introspective-type support functions for things
   2 like call tips and command auto completion."""
   3
   4 __author__ = "Patrick K. O'Brien <pobrien@orbtech.com>"
   5 __cvsid__ = "$Id$"
   6 __version__ = "$Revision$"[11:-2]
   7
   8 import inspect
   9 import string
  10 import types
  11
  12 def getAutoCompleteList(command='', locals=None, includeMagic=1, \
  13                         includeSingle=1, includeDouble=1):
  14     """Return list of auto-completion options for command.
  15
  16     The list of options will be based on the locals namespace."""
  17
  18     # Get the proper chunk of code from the command.
  19     root = getRoot(command, terminator='.')
  20     try:
  21         object = eval(root, locals)
  22         attributes = getAttributeNames(object, includeMagic, \
  23                                        includeSingle, includeDouble)
  24         return attributes
  25     except:
  26         return []
  27
  28 def getAttributeNames(object, includeMagic=1, includeSingle=1, includeDouble=1):
  29     """Return list of unique attributes, including inherited, for an object."""
  30     attributes = []
  31     dict = {}
  32     if includeMagic:
  33         try: attributes += object._getAttributeNames()
  34         except: pass
  35     # Get all attribute names, removing duplicates from the attribute list.
  36     for item in getAllAttributeNames(object):
  37         dict[item] = None
  38     attributes += dict.keys()
  39     attributes.sort(lambda x, y: cmp(x.upper(), y.upper()))
  40     if not includeSingle:
  41         attributes = filter(lambda item: item[0]!='_' or item[1]=='_', attributes)
  42     if not includeDouble:
  43         attributes = filter(lambda item: item[:2]!='__', attributes)
  44     # Make sure we haven't picked up any bogus attributes somehow.
  45     attributes = [attribute for attribute in attributes if hasattr(object, attribute)]
  46     return attributes
  47
  48 def getAllAttributeNames(object):
  49     """Return list of all attributes, including inherited, for an object.
  50
  51     Recursively walk through a class and all base classes.
  52     """
  53     # !!!
  54     # !!! Do Not use hasattr() as a test anywhere in this function,
  55     # !!! because it is unreliable with remote objects - xmlrpc, soap, etc.
  56     # !!!
  57     attributes = []
  58     # Wake up sleepy objects - a hack for ZODB objects in "ghost" state.
  59     wakeupcall = dir(object)
  60     del wakeupcall
  61     # Get attributes available through the normal convention.
  62     attributes += dir(object)
  63     try:
  64         keys = object.__dict__.keys()
  65     except:
  66         pass
  67     else:
  68         attributes += keys
  69     # For a class instance, get the attributes for the class.
  70     if hasattr(object, '__class__'):
  71         # Break a circular reference. This happens with extension classes.
  72         if object.__class__ is object:
  73             pass
  74         else:
  75             attributes += getAllAttributeNames(object.__class__)
  76     # Also get attributes from any and all parent classes.
  77     try:
  78         bases = object.__bases__
  79     except:
  80         pass
  81     else:
  82         if isinstance(bases, type(())):
  83             for base in bases:
  84                 if type(base) is types.TypeType:
  85                     # Break a circular reference. Happens in Python 2.2.
  86                     pass
  87                 else:
  88                     attributes += getAllAttributeNames(base)
  89     return attributes
  90
  91 def getCallTip(command='', locals=None):
  92     """Return call tip text for a command.
  93
  94     The call tip information will be based on the locals namespace."""
  95
  96     calltip = ('', '', '')
  97     # Get the proper chunk of code from the command.
  98     root = getRoot(command, terminator='(')
  99     try:
 100         object = eval(root, locals)
 101     except:
 102         return calltip
 103     name = ''
 104     dropSelf = 1
 105     # Switch to the object that has the information we need.
 106     if inspect.isbuiltin(object):
 107         # Builtin functions don't have an argspec that we can get.
 108         pass
 109     elif inspect.ismethod(object) or hasattr(object, 'im_func'):
 110         # Get the function from the object otherwise inspect.getargspec()
 111         # complains that the object isn't a Python function.
 112         object = object.im_func
 113     elif inspect.isclass(object):
 114         # Get the __init__ method function for the class.
 115         constructor = getConstructor(object)
 116         if constructor is not None:
 117             object = constructor
 118     elif callable(object):
 119         # Get the __call__ method instead.
 120         try:
 121             object = object.__call__.im_func
 122         except:
 123             dropSelf = 0
 124     else:
 125         dropSelf = 0
 126     if hasattr(object, '__name__'):
 127         name = object.__name__
 128     tip1 = ''
 129     argspec = ''
 130     if inspect.isbuiltin(object):
 131         # Builtin functions don't have an argspec that we can get.
 132         pass
 133     elif inspect.isfunction(object):
 134         # tip1 is a string like: "getCallTip(command='', locals=None)"
 135         argspec = apply(inspect.formatargspec, inspect.getargspec(object))
 136         if dropSelf:
 137             # The first parameter to a method is a reference to the
 138             # instance, usually coded as "self", and is passed
 139             # automatically by Python and therefore we want to drop it.
 140             temp = argspec.split(',')
 141             if len(temp) == 1:  # No other arguments.
 142                 argspec = '()'
 143             else:  # Drop the first argument.
 144                 argspec = '(' + ','.join(temp[1:]).lstrip()
 145         tip1 = name + argspec
 146     doc = inspect.getdoc(object)
 147     if doc:
 148         # tip2 is the first separated line of the docstring, like:
 149         # "Return call tip text for a command."
 150         # tip3 is the rest of the docstring, like:
 151         # "The call tip information will be based on ... <snip>
 152         docpieces = doc.split('\n\n')
 153         tip2 = docpieces[0]
 154         tip3 = '\n\n'.join(docpieces[1:])
 155         tip = '%s\n\n%s\n\n%s' % (tip1, tip2, tip3)
 156     else:
 157         tip = tip1
 158     calltip = (name, argspec[1:-1], tip.strip())
 159     return calltip
 160
 161 def getConstructor(object):
 162     """Return constructor for class object, or None if there isn't one."""
 163     try:
 164         return object.__init__.im_func
 165     except AttributeError:
 166         for base in object.__bases__:
 167             constructor = getConstructor(base)
 168             if constructor is not None:
 169                 return constructor
 170     return None
 171
 172 def getRoot(command, terminator=None):
 173     """Return the rightmost root portion of an arbitrary Python command.
 174
 175     The command would normally terminate with a "(" or ".". Anything after
 176     the terminator will be dropped, allowing you to get back to the root.
 177     Return only the root portion that can be eval()'d without side effects.
 178     """
 179     root = ''
 180     validChars = "._" + string.uppercase + string.lowercase + string.digits
 181     if terminator:
 182         # Drop the final terminator and anything that follows.
 183         pieces = command.split(terminator)
 184         if len(pieces) > 1:
 185             command = terminator.join(pieces[:-1])
 186     if len(command) == 0:
 187         root = ''
 188     elif command in ("''", '""', '""""""', '[]', '()', '{}'):
 189         # Let empty type delimiter pairs go through.
 190         root = command
 191     else:
 192         # Go backward through the command until we hit an "invalid" character.
 193         i = len(command)
 194         while i and command[i-1] in validChars:
 195             i -= 1
 196         # Detect situations where we are in the middle of a string.
 197         # This code catches the simplest case, but needs to catch others.
 198         if command[i-1] in ("'", '"'):
 199             # We're in the middle of a string so we aren't dealing with an
 200             # object and it would be misleading to return anything here.
 201             root = ''
 202         else:
 203             # Grab everything from the "invalid" character to the end.
 204             root = command[i:]
 205     return root
 206
 207
 208