An alias to another magic function. An alias is determined by its magic name and magic kind. Lookup is done at call time, so if the underlying magic changes the alias will call the new function. Use the :meth:`MagicsManager.register_alias` method or the `%alias_magic` magic fun
| 662 | |
| 663 | |
| 664 | class MagicAlias(object): |
| 665 | """An alias to another magic function. |
| 666 | |
| 667 | An alias is determined by its magic name and magic kind. Lookup |
| 668 | is done at call time, so if the underlying magic changes the alias |
| 669 | will call the new function. |
| 670 | |
| 671 | Use the :meth:`MagicsManager.register_alias` method or the |
| 672 | `%alias_magic` magic function to create and register a new alias. |
| 673 | """ |
| 674 | def __init__(self, shell, magic_name, magic_kind, magic_params=None): |
| 675 | self.shell = shell |
| 676 | self.magic_name = magic_name |
| 677 | self.magic_params = magic_params |
| 678 | self.magic_kind = magic_kind |
| 679 | |
| 680 | self.pretty_target = '%s%s' % (magic_escapes[self.magic_kind], self.magic_name) |
| 681 | self.__doc__ = "Alias for `%s`." % self.pretty_target |
| 682 | |
| 683 | self._in_call = False |
| 684 | |
| 685 | def __call__(self, *args, **kwargs): |
| 686 | """Call the magic alias.""" |
| 687 | fn = self.shell.find_magic(self.magic_name, self.magic_kind) |
| 688 | if fn is None: |
| 689 | raise UsageError("Magic `%s` not found." % self.pretty_target) |
| 690 | |
| 691 | # Protect against infinite recursion. |
| 692 | if self._in_call: |
| 693 | raise UsageError("Infinite recursion detected; " |
| 694 | "magic aliases cannot call themselves.") |
| 695 | self._in_call = True |
| 696 | try: |
| 697 | if self.magic_params: |
| 698 | args_list = list(args) |
| 699 | args_list[0] = self.magic_params + " " + args[0] |
| 700 | args = tuple(args_list) |
| 701 | return fn(*args, **kwargs) |
| 702 | finally: |
| 703 | self._in_call = False |