From b7491ba6626b909c9c90682b02963fd5dc55e2f6 2012-05-26 03:25:55
From: Fernando Perez <Fernando.Perez@berkeley.edu>
Date: 2012-05-26 03:25:55
Subject: [PATCH] Create decorators for standalone magic functions, as per review.x

---

diff --git a/IPython/core/magic.py b/IPython/core/magic.py
index 230175a..d61ea88 100644
--- a/IPython/core/magic.py
+++ b/IPython/core/magic.py
@@ -130,16 +130,66 @@ def _magic_marker(magic_type):
         else:
             raise ValueError("Decorator can only be called with "
                              "string or function")
+        return retval
+
+    return magic_deco
+
 
+def _function_magic_marker(magic_type):
+    validate_type(magic_type)
+
+    # This is a closure to capture the magic_type.  We could also use a class,
+    # but it's overkill for just that one bit of state.
+    def magic_deco(arg):
+        call = lambda f, *a, **k: f(*a, **k)
+
+        # Find get_ipython() in the caller's namespace
+        caller = sys._getframe(1)
+        for ns in ['f_locals', 'f_globals', 'f_builtins']:
+            get_ipython = getattr(caller, ns).get('get_ipython')
+            if get_ipython is not None:
+                break
+        else:
+            raise('Decorator can only run in context where `get_ipython` exists')
+
+        ip = get_ipython()
+
+        if callable(arg):
+            # "Naked" decorator call (just @foo, no args)
+            func = arg
+            #name = func.func_name
+            #func.magic_name = name
+            ip.register_magic_function(func)
+            retval = decorator(call, func)
+        elif isinstance(arg, basestring):
+            # Decorator called with arguments (@foo('bar'))
+            name = arg
+            def mark(func, *a, **kw):
+                #func.magic_name = name
+                ip.register_magic_function(func)
+                return decorator(call, func)
+            retval = mark
+        else:
+            raise ValueError("Decorator can only be called with "
+                             "string or function")
         return retval
 
     return magic_deco
 
 
+# Create the actual decorators for public use
+
+# These three are used to decorate methods in class definitions
 line_magic = _magic_marker('line')
 cell_magic = _magic_marker('cell')
 line_cell_magic = _magic_marker('line_cell')
 
+# These three decorate standalone functions and perform the decoration
+# immediately.  They can only run where get_ipython() works
+register_line_magic = _function_magic_marker('line')
+register_cell_magic = _function_magic_marker('cell')
+register_line_cell_magic = _function_magic_marker('line_cell')
+
 #-----------------------------------------------------------------------------
 # Core Magic classes
 #-----------------------------------------------------------------------------
diff --git a/IPython/core/magics/__init__.py b/IPython/core/magics/__init__.py
index b4b8cac..fa82e20 100644
--- a/IPython/core/magics/__init__.py
+++ b/IPython/core/magics/__init__.py
@@ -1,7 +1,7 @@
 """Implementation of all the magic functions built into IPython.
 """
 #-----------------------------------------------------------------------------
-#  Copyright (c) 2012, IPython Development Team.
+#  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #