X-Git-Url: https://git.openstreetmap.org./osqa.git/blobdiff_plain/9b6be99a1eed1adddfd062642f6ca23f79d14aea..a967cc431af1efebc9af8dc5fbfa64fd71a00529:/forum/modules/decorators.py

diff --git a/forum/modules/decorators.py b/forum/modules/decorators.py
index 90109a9..11af9e3 100644
--- a/forum/modules/decorators.py
+++ b/forum/modules/decorators.py
@@ -1,67 +1,164 @@
 import inspect
 
 class DecoratableObject(object):
-    def __init__(self, fn):
+    MODE_OVERRIDE = 0
+    MODE_PARAMS = 1
+    MODE_RESULT = 2
+
+    def __init__(self, fn, is_method=False):
         self._callable = fn
+        self.is_method = is_method
 
-    def _decorate(self, fn, needs_origin):
-        origin = self._callable
+        self._params_decoration = None
+        self._result_decoration = None
 
-        if needs_origin:
-            self._callable = lambda *args, **kwargs: fn(origin, *args, **kwargs)
-        else:
-            self._callable = lambda *args, **kwargs: fn(*args, **kwargs)
+    def _decorate(self, fn, mode, **kwargs):
+        if mode == self.MODE_OVERRIDE:
+            self._decorate_full(fn, **kwargs)
+        elif mode == self.MODE_PARAMS:
+            self._decorate_params(fn)
+        elif mode == self.MODE_RESULT:
+            self._decorate_result(fn, **kwargs)
 
-    def _decorate_method(self, fn, needs_origin):
+    def _decorate_full(self, fn, needs_origin=True):
         origin = self._callable
 
         if needs_origin:
-            self._callable = lambda inst, *args, **kwargs: fn(inst, origin, *args, **kwargs)
+            if self.is_method:
+                self._callable = lambda inst, *args, **kwargs: fn(inst, origin, *args, **kwargs)
+            else:
+                self._callable = lambda *args, **kwargs: fn(origin, *args, **kwargs)
         else:
-            self._callable = lambda inst, *args, **kwargs: fn(inst, *args, **kwargs)
+            self._callable = fn
 
+    def _decorate_params(self, fn):
+        if not self._params_decoration:
+            self._params_decoration = []
 
-    def __call__(self, *args, **kwargs):
-        return self._callable(*args, **kwargs)
+        self._params_decoration.append(fn)
+
+    def _decorate_result(self, fn, needs_params=False):
+        if not self._result_decoration:
+            self._result_decoration = []
 
+        fn._needs_params = needs_params
+        self._result_decoration.append(fn)
 
-def _decorate_method(origin, needs_origin):
+    def __call__(self, *args, **kwargs):
+        if self._params_decoration:
+            for dec in self._params_decoration:
+                try:
+                    args, kwargs = dec(*args, **kwargs)
+                except ReturnImediatelyException, e:
+                    return e.ret
+
+        res = self._callable(*args, **kwargs)
+
+        if self._result_decoration:
+            for dec in self._result_decoration:
+                if dec._needs_params:
+                    res = dec(res, *args, **kwargs)
+                else:
+                    res = dec(res)
+
+        return res
+
+class ReturnImediatelyException(Exception):
+    def __init__(self, ret):
+        super(Exception, self).__init__()
+        self.ret = ret
+
+def _check_decoratable(origin, install=True):
     if not hasattr(origin, '_decoratable_obj'):
-        name = origin.__name__
-        cls = origin.im_class
+        if inspect.ismethod(origin) and not hasattr(origin, '_decoratable_obj'):
+            decoratable = DecoratableObject(origin)
+
+            def decoratable_method(self, *args, **kwargs):
+                return decoratable(self, *args, **kwargs)
+
+            decoratable_method._decoratable_obj = decoratable
+
+            def decoratable_decorate(fn, mode, **kwargs):
+                decoratable._decorate(fn, mode, **kwargs)
+
+            decoratable_method._decorate = decoratable_decorate
+
+            if install:
+                setattr(origin.im_class, origin.__name__, decoratable_method)
+
+            return decoratable_method
+                
+        elif inspect.isfunction(origin):
+            decoratable = DecoratableObject(origin)
+
+            def decorated(*args, **kwargs):
+                return decoratable(*args, **kwargs)
+
+            decorated._decoratable_obj = decoratable
+
+            if install:
+                setattr(inspect.getmodule(origin), origin.__name__, decorated)
 
-        decoratable = DecoratableObject(origin)
+            decorated.__name__ = origin.__name__
+            decorated.__module__ = origin.__module__
 
-        def decoratable_method(self, *args, **kwargs):
-            return decoratable(self, *args, **kwargs)
+            return decorated
 
-        decoratable_method._decoratable_obj = decoratable
-        setattr(cls, name, decoratable_method)
-    else:
-        decoratable = origin._decoratable_obj
+    return origin
+
+
+def decorate(origin, needs_origin=True):
+    origin = _check_decoratable(origin)
+
+    def decorator(fn):
+        origin._decoratable_obj._decorate(fn, DecoratableObject.MODE_OVERRIDE, needs_origin=needs_origin)
+        
+    return decorator
+
+
+def _decorate_params(origin):
+    origin = _check_decoratable(origin)
 
     def decorator(fn):
-        decoratable._decorate_method(fn, needs_origin)
+        origin._decoratable_obj._decorate(fn, DecoratableObject.MODE_PARAMS)
 
     return decorator
 
-def _decorate_function(origin, needs_origin):
-    if not isinstance(origin, DecoratableObject):
-        mod = inspect.getmodule(origin)
+decorate.params = _decorate_params
 
-        name = origin.__name__
-        origin = DecoratableObject(origin)
-        setattr(mod, name, DecoratableObject(origin))
+def _decorate_result(origin, needs_params=False):
+    origin = _check_decoratable(origin)
 
     def decorator(fn):
-        origin._decorate(fn, needs_origin)
+        origin._decoratable_obj._decorate(fn, DecoratableObject.MODE_RESULT, needs_params=needs_params)
 
     return decorator
 
+decorate.result = _decorate_result
 
-def decorate(origin, needs_origin=True):
-    if inspect.ismethod(origin):
-        return _decorate_method(origin, needs_origin)
+def _decorate_with(fn):
+    def decorator(origin):
+        origin = _check_decoratable(origin)
+        origin._decoratable_obj._decorate(fn, DecoratableObject.MODE_OVERRIDE, needs_origin=True)
+        return origin
+    return decorator
+
+decorate.withfn = _decorate_with
+
+def _decorate_result_with(fn, needs_params=False):
+    def decorator(origin):
+        origin = _check_decoratable(origin)
+        origin._decoratable_obj._decorate(fn, DecoratableObject.MODE_RESULT, needs_params=needs_params)
+        return origin
+    return decorator
+
+decorate.result.withfn = _decorate_result_with
+
+def _decorate_params_with(fn):
+    def decorator(origin):
+        origin = _check_decoratable(origin)
+        origin._decoratable_obj._decorate(fn, DecoratableObject.MODE_PARAMS)
+        return origin
+    return decorator
 
-    if inspect.isfunction(origin):
-        return _decorate_function(origin, needs_origin)
\ No newline at end of file
+decorate.params.withfn = _decorate_params_with
\ No newline at end of file