extensions: add docstring for wrapcommand().

mercurial/extensions.py

@@ -1,286 +1,298
 # extensions.py - extension handling for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 import imp, os
 import util, cmdutil, help, error
 from i18n import _, gettext
 
 _extensions = {}
 _order = []
 
 def extensions():
     for name in _order:
         module = _extensions[name]
         if module:
             yield name, module
 
 def find(name):
     '''return module with given extension name'''
     try:
         return _extensions[name]
     except KeyError:
         for k, v in _extensions.iteritems():
             if k.endswith('.' + name) or k.endswith('/' + name):
                 return v
         raise KeyError(name)
 
 def loadpath(path, module_name):
     module_name = module_name.replace('.', '_')
     path = util.expandpath(path)
     if os.path.isdir(path):
         # module/__init__.py style
         d, f = os.path.split(path.rstrip('/'))
         fd, fpath, desc = imp.find_module(f, [d])
         return imp.load_module(module_name, fd, fpath, desc)
     else:
         return imp.load_source(module_name, path)
 
 def load(ui, name, path):
     # unused ui argument kept for backwards compatibility
     if name.startswith('hgext.') or name.startswith('hgext/'):
         shortname = name[6:]
     else:
         shortname = name
     if shortname in _extensions:
         return
     _extensions[shortname] = None
     if path:
         # the module will be loaded in sys.modules
         # choose an unique name so that it doesn't
         # conflicts with other modules
         mod = loadpath(path, 'hgext.%s' % name)
     else:
         def importh(name):
             mod = __import__(name)
             components = name.split('.')
             for comp in components[1:]:
                 mod = getattr(mod, comp)
             return mod
         try:
             mod = importh("hgext.%s" % name)
         except ImportError:
             mod = importh(name)
     _extensions[shortname] = mod
     _order.append(shortname)
 
 def loadall(ui):
     result = ui.configitems("extensions")
     newindex = len(_order)
     for (name, path) in result:
         if path:
             if path[0] == '!':
                 continue
         try:
             load(ui, name, path)
         except KeyboardInterrupt:
             raise
         except Exception, inst:
             if path:
                 ui.warn(_("*** failed to import extension %s from %s: %s\n")
                         % (name, path, inst))
             else:
                 ui.warn(_("*** failed to import extension %s: %s\n")
                         % (name, inst))
             if ui.traceback():
                 return 1
 
     for name in _order[newindex:]:
         uisetup = getattr(_extensions[name], 'uisetup', None)
         if uisetup:
             uisetup(ui)
 
     for name in _order[newindex:]:
         extsetup = getattr(_extensions[name], 'extsetup', None)
         if extsetup:
             try:
                 extsetup(ui)
             except TypeError:
                 if extsetup.func_code.co_argcount != 0:
                     raise
                 extsetup() # old extsetup with no ui argument
 
 def wrapcommand(table, command, wrapper):
+    '''Wrap the command named `command' in table
+
+    Replace command in the command table with wrapper. The wrapped command will
+    be inserted into the command table specified by the table argument.
+
+    The wrapper will be called like
+
+      wrapper(orig, *args, **kwargs)
+
+    where orig is the original (wrapped) function, and *args, **kwargs
+    are the arguments passed to it.
+    '''
     aliases, entry = cmdutil.findcmd(command, table)
     for alias, e in table.iteritems():
         if e is entry:
             key = alias
             break
 
     origfn = entry[0]
     def wrap(*args, **kwargs):
         return util.checksignature(wrapper)(
             util.checksignature(origfn), *args, **kwargs)
 
     wrap.__doc__ = getattr(origfn, '__doc__')
     wrap.__module__ = getattr(origfn, '__module__')
 
     newentry = list(entry)
     newentry[0] = wrap
     table[key] = tuple(newentry)
     return entry
 
 def wrapfunction(container, funcname, wrapper):
     '''Wrap the function named funcname in container
 
     It is replacing with your wrapper. The container is typically a
     module, class, or instance.
 
     The wrapper will be called like
 
       wrapper(orig, *args, **kwargs)
 
     where orig is the original (wrapped) function, and *args, **kwargs
     are the arguments passed to it.
 
     Wrapping methods of the repository object is not recommended since
     it conflicts with extensions that extend the repository by
     subclassing. All extensions that need to extend methods of
     localrepository should use this subclassing trick: namely,
     reposetup() should look like
 
       def reposetup(ui, repo):
           class myrepo(repo.__class__):
               def whatever(self, *args, **kwargs):
                   [...extension stuff...]
                   super(myrepo, self).whatever(*args, **kwargs)
                   [...extension stuff...]
 
           repo.__class__ = myrepo
 
     In general, combining wrapfunction() with subclassing does not
     work. Since you cannot control what other extensions are loaded by
     your end users, you should play nicely with others by using the
     subclass trick.
     '''
     def wrap(*args, **kwargs):
         return wrapper(origfn, *args, **kwargs)
 
     origfn = getattr(container, funcname)
     setattr(container, funcname, wrap)
     return origfn
 
 def _disabledpaths(strip_init=False):
     '''find paths of disabled extensions. returns a dict of {name: path}
     removes /__init__.py from packages if strip_init is True'''
     import hgext
     extpath = os.path.dirname(os.path.abspath(hgext.__file__))
     try: # might not be a filesystem path
         files = os.listdir(extpath)
     except OSError:
         return {}
 
     exts = {}
     for e in files:
         if e.endswith('.py'):
             name = e.rsplit('.', 1)[0]
             path = os.path.join(extpath, e)
         else:
             name = e
             path = os.path.join(extpath, e, '__init__.py')
             if not os.path.exists(path):
                 continue
             if strip_init:
                 path = os.path.dirname(path)
         if name in exts or name in _order or name == '__init__':
             continue
         exts[name] = path
     return exts
 
 def _disabledhelp(path):
     '''retrieve help synopsis of a disabled extension (without importing)'''
     try:
         file = open(path)
     except IOError:
         return
     else:
         doc = help.moduledoc(file)
         file.close()
 
     if doc: # extracting localized synopsis
         return gettext(doc).splitlines()[0]
     else:
         return _('(no help text available)')
 
 def disabled():
     '''find disabled extensions from hgext
     returns a dict of {name: desc}, and the max name length'''
 
     paths = _disabledpaths()
     if not paths:
         return None, 0
 
     exts = {}
     maxlength = 0
     for name, path in paths.iteritems():
         doc = _disabledhelp(path)
         if not doc:
             continue
 
         exts[name] = doc
         if len(name) > maxlength:
             maxlength = len(name)
 
     return exts, maxlength
 
 def disabledext(name):
     '''find a specific disabled extension from hgext. returns desc'''
     paths = _disabledpaths()
     if name in paths:
         return _disabledhelp(paths[name])
 
 def disabledcmd(cmd, strict=False):
     '''import disabled extensions until cmd is found.
     returns (cmdname, extname, doc)'''
 
     paths = _disabledpaths(strip_init=True)
     if not paths:
         raise error.UnknownCommand(cmd)
 
     def findcmd(cmd, name, path):
         try:
             mod = loadpath(path, 'hgext.%s' % name)
         except Exception:
             return
         try:
             aliases, entry = cmdutil.findcmd(cmd,
                 getattr(mod, 'cmdtable', {}), strict)
         except (error.AmbiguousCommand, error.UnknownCommand):
             return
         for c in aliases:
             if c.startswith(cmd):
                 cmd = c
                 break
         else:
             cmd = aliases[0]
         return (cmd, name, mod)
 
     # first, search for an extension with the same name as the command
     path = paths.pop(cmd, None)
     if path:
         ext = findcmd(cmd, cmd, path)
         if ext:
             return ext
 
     # otherwise, interrogate each extension until there's a match
     for name, path in paths.iteritems():
         ext = findcmd(cmd, name, path)
         if ext:
             return ext
 
     raise error.UnknownCommand(cmd)
 
 def enabled():
     '''return a dict of {name: desc} of extensions, and the max name length'''
     exts = {}
     maxlength = 0
     for ename, ext in extensions():
         doc = (gettext(ext.__doc__) or _('(no help text available)'))
         ename = ename.split('.')[-1]
         maxlength = max(len(ename), maxlength)
         exts[ename] = doc.splitlines()[0].strip()
 
     return exts, maxlength