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