some cleanup to scrapy.xpath module

--HG--
rename : scrapy/xpath/constructors.py => scrapy/xpath/factories.py

scrapy/xpath/document.py

@@ -3,12 +3,12 @@ This module contains a simple class (Libxml2Document) to wrap libxml2 documents
 (xmlDoc) for proper garbage collection.
 """
 
-from scrapy.xpath.constructors import xmlDoc_from_html
+from scrapy.xpath.factories import xmlDoc_from_html
 
 class Libxml2Document(object):
 
-    def __init__(self, response, constructor=xmlDoc_from_html):
-        self.xmlDoc = constructor(response)
+    def __init__(self, response, factory=xmlDoc_from_html):
+        self.xmlDoc = factory(response)
         self.xpathContext = self.xmlDoc.xpathNewContext()
 
     def __del__(self):

scrapy/xpath/extension.py

@@ -5,16 +5,16 @@ The ResponseLibxml2 extension causes the Response objects to grow a new method
 
 from scrapy.http import Response
 from scrapy.xpath.document import Libxml2Document
-from scrapy.xpath.constructors import xmlDoc_from_html
+from scrapy.xpath.factories import xmlDoc_from_html
 
 class ResponseLibxml2(object):
     def __init__(self):
         setattr(Response, 'getlibxml2doc', getlibxml2doc)
 
-def getlibxml2doc(response, constructor=xmlDoc_from_html):
-    cachekey = 'lx2doc_%s' % constructor.__name__
+def getlibxml2doc(response, factory=xmlDoc_from_html):
+    cachekey = 'lx2doc_%s' % factory.__name__
     if cachekey not in response.cache:
-        lx2doc = Libxml2Document(response, constructor=constructor)
+        lx2doc = Libxml2Document(response, factory=factory)
         response.cache[cachekey] = lx2doc
     return response.cache[cachekey]
 

scrapy/xpath/selector.py

@@ -8,7 +8,7 @@ import libxml2
 
 from scrapy.http import TextResponse
 from scrapy.xpath.extension import Libxml2Document
-from scrapy.xpath.constructors import xmlDoc_from_html, xmlDoc_from_xml
+from scrapy.xpath.factories import xmlDoc_from_html, xmlDoc_from_xml
 from scrapy.utils.python import flatten, unicode_to_str
 from scrapy.utils.misc import extract_regex
 
@@ -23,19 +23,23 @@ class XPathSelector(object):
     - HtmlXPathSelector (for HTML content)
     """
 
-    def __init__(self, response=None, text=None, node=None, parent=None, expr=None, constructor=xmlDoc_from_html):
+    xmlDoc_factory = staticmethod(xmlDoc_from_html)
+
+    def __init__(self, response=None, text=None, node=None, parent=None, expr=None):
         if parent:
             self.doc = parent.doc
             self.xmlNode = node
         elif response:
             try:
-                self.doc = response.getlibxml2doc(constructor=constructor)  # try with cached version first
+                # try with cached version first
+                self.doc = response.getlibxml2doc(factory=self.xmlDoc_factory)
             except AttributeError:
-                self.doc = Libxml2Document(response, constructor=constructor)
+                self.doc = Libxml2Document(response, factory=self.xmlDoc_factory)
             self.xmlNode = self.doc.xmlDoc
         elif text:
-            response = TextResponse(url=None, body=unicode_to_str(text), encoding='utf-8')
-            self.doc = Libxml2Document(response, constructor=constructor)
+            response = TextResponse(url=None, body=unicode_to_str(text), \
+                encoding='utf-8')
+            self.doc = Libxml2Document(response, factory=self.xmlDoc_factory)
             self.xmlNode = self.doc.xmlDoc
         self.expr = expr
         self.response = response
@@ -51,10 +55,11 @@ class XPathSelector(object):
                 raise ValueError("Invalid XPath: %s" % xpath)
             cls = type(self)
             if hasattr(xpath_result, '__iter__'):
-                return XPathSelectorList([cls(node=node, parent=self, expr=xpath, response=self.response)
-                                          for node in xpath_result])
+                return XPathSelectorList([cls(node=node, parent=self, expr=xpath, \
+                    response=self.response) for node in xpath_result])
             else:
-                return XPathSelectorList([cls(node=xpath_result, parent=self, expr=xpath, response=self.response)])
+                return XPathSelectorList([cls(node=xpath_result, parent=self, \
+                    expr=xpath, response=self.response)])
         else:
             return XPathSelectorList([])
     __call__ = x
@@ -132,12 +137,9 @@ class XPathSelectorList(list):
 
 class XmlXPathSelector(XPathSelector):
     """XPathSelector for XML content"""
-    def __init__(self, *args, **kwargs):
-        kwargs['constructor'] = xmlDoc_from_xml
-        XPathSelector.__init__(self, *args, **kwargs)
+    xmlDoc_factory = staticmethod(xmlDoc_from_xml)
+
 
 class HtmlXPathSelector(XPathSelector):
     """XPathSelector for HTML content"""
-    def __init__(self, *args, **kwargs):
-        kwargs['constructor'] = xmlDoc_from_html
-        XPathSelector.__init__(self, *args, **kwargs)
+    xmlDoc_factory = staticmethod(xmlDoc_from_html)