Turned unquote adaptor into a function, and added adaptor factory

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40372

scrapy/trunk/scrapy/contrib/adaptors/__init__.py

@@ -1,4 +1,26 @@
+import inspect
+
 from scrapy.contrib.adaptors.extraction import extract, extract_unquoted, ExtractImages
-from scrapy.contrib.adaptors.markup import remove_tags, remove_root, Unquote
-from scrapy.contrib.adaptors.misc import to_unicode, clean_spaces, strip_list, drop_empty, canonicalize_urls, Delist, Regex
+from scrapy.contrib.adaptors.markup import remove_tags, remove_root, unquote
+from scrapy.contrib.adaptors.misc import to_unicode, clean_spaces, strip_list, drop_empty, canonicalize_urls, delist, Regex
 from scrapy.utils.python import unique, flatten
+
+def adaptor_gen(*args):
+    subadaptors = []
+    arg_mappings = []
+    for subadaptor in args:
+        if callable(subadaptor):
+            if inspect.isfunction(subadaptor):
+                func_args, varargs, varkw, defaults = inspect.getargspec(subadaptor)
+                arg_mappings.append(func_args[1:])
+            else:
+                arg_mappings.append([])
+            subadaptors.append(subadaptor)
+    
+    def _adaptor(value, **kwargs):
+        for index, subadaptor in enumerate(subadaptors):
+            adaptor_args = dict((key, val) for key, val in kwargs.items() if key in arg_mappings[index])
+            value = subadaptor(value, **adaptor_args)
+        return value
+
+    return _adaptor

scrapy/trunk/scrapy/contrib/adaptors/markup.py

@@ -21,7 +21,7 @@ def remove_root(value):
         return value
     return [ _remove_root(v) for v in value ]
 
-class Unquote(object):
+def unquote(value, keep_entities=None):
     """
     Receives a list of strings, removes all of the
     entities the strings may have, and returns
@@ -30,10 +30,8 @@ class Unquote(object):
     Input: iterable with strings
     Output: list of strings
     """
-    def __init__(self, keep=['lt', 'amp']):
-        self.keep = keep
-
-    def __call__(self, value):
-        return [ remove_entities(v, keep=self.keep) for v in value ]
+    if keep_entities is None:
+        keep_entities = ['lt', 'amp']
+    return [ remove_entities(v, keep=keep_entities) for v in value ]