Reorganized XMLSchema instatiation.

* Only instantiate an XMLSchema object for the official SLD spec when validating a document. * Store a local copy of the official SLD spec as a local cache.
azavea · Aug 31, 2012 · 39011b3 · 39011b3
1 parent a255e77
commit 39011b3
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diff --git a/setup.py b/setup.py
@@ -3,7 +3,7 @@
 
 License
 =======
-Copyright 2011 David Zwarg <dzwarg@azavea.com>
+Copyright 2011-2012 David Zwarg <dzwarg@azavea.com>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -46,7 +46,7 @@ def finalize_options(self):
 
 setup(
     name = "python-sld",
-    version = "1.0.8",
+    version = "1.0.9",
     author = "David Zwarg",
     author_email = "dzwarg@azavea.com",
     description = ("A simple python library that enables dynamic SLD creation and manipulation."),

diff --git a/sld/__init__.py b/sld/__init__.py
@@ -11,7 +11,7 @@
 
 License
 =======
-Copyright 2011 David Zwarg <U{dzwarg@azavea.com}>
+Copyright 2011-2012 David Zwarg <U{dzwarg@azavea.com}>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -27,9 +27,9 @@
 
 @author: David Zwarg
 @contact: dzwarg@azavea.com
-@copyright: 2011, Azavea
+@copyright: 2011-2012, Azavea
 @license: Apache 2.0
-@version: 1.0.8
+@version: 1.0.9
 @newfield prop: Property, Properties
 """
 from lxml.etree import parse, Element, XMLSchema, XMLSyntaxError, tostring
@@ -1382,7 +1382,7 @@ class StyledLayerDescriptor(SLDNode):
     """
 
     _cached_schema = None
-    """A cached schema document, to prevent multiple requests from occurring."""
+    """A cached schema document, to prevent repeated web requests for the schema document."""
 
     def __init__(self, sld_file=None):
         """
@@ -1399,32 +1399,45 @@ def __init__(self, sld_file=None):
             logging.debug('Storing new schema into cache.')
 
             localschema = NamedTemporaryFile(delete=False)
-            schema_url = 'http://schemas.opengis.net/sld/1.0.0/StyledLayerDescriptor.xsd'
-            resp = urllib2.urlopen(schema_url)
-            localschema.write(resp.read())
-            resp.close()
+
+            localschema_backup_path = './StyledLayerDescriptor-backup.xsd'
+            try:
+                logging.debug('Cache hit for backup schema document.')
+                localschema_backup = open(localschema_backup_path, 'r')
+            except IOError:
+                logging.debug('Cache miss for backup schema document.')
+                localschema_backup = open(localschema_backup_path, 'w')
+
+                schema_url = 'http://schemas.opengis.net/sld/1.0.0/StyledLayerDescriptor.xsd'
+                resp = urllib2.urlopen(schema_url)
+                localschema_backup.write(resp.read())
+                resp.close()
+                localschema_backup.close()
+                localschema_backup = open(localschema_backup_path, 'r')
+
+            localschema.write(localschema_backup.read())
             localschema.seek(0)
+            localschema_backup.close()
 
-            theschema = parse(localschema)
+            self._schemadoc = parse(localschema)
             localschema.close()
 
             StyledLayerDescriptor._cached_schema = localschema.name
         else:
             logging.debug('Fetching schema from cache.')
 
             localschema = open(StyledLayerDescriptor._cached_schema, 'r')
-            theschema = parse(localschema)
+            self._schemadoc = parse(localschema)
             localschema.close()
 
-        self._schema = XMLSchema(theschema)
-
         if not sld_file is None:
             self._node = parse(sld_file)
-
+            self._schema = XMLSchema(self._schemadoc)
             if not self._schema.validate(self._node):
                 logging.warn('SLD File "%s" does not validate against the SLD schema.', sld_file)
         else:
             self._node = Element("{%s}StyledLayerDescriptor" % SLDNode._nsmap['sld'], version="1.0.0", nsmap=SLDNode._nsmap)
+            self._schema = None
 
         setattr(self.__class__, 'NamedLayer', SLDNode.makeproperty('sld', cls=NamedLayer,
             docstring="The named layer of the SLD."))
@@ -1469,10 +1482,13 @@ def validate(self):
         """
         self.normalize()
 
-        if self._node is None or self._schema is None:
-            logging.debug('The node or schema is empty, and cannot be validated.')
+        if self._node is None:
+            logging.debug('The node is empty, and cannot be validated.')
             return False
 
+        if self._schema is None:
+            self._schema = XMLSchema(self._schemadoc)
+
         is_valid = self._schema.validate(self._node)
 
         for msg in self._schema.error_log:

diff --git a/sld/run_tests.py b/sld/run_tests.py
@@ -4,7 +4,7 @@
 
 License
 =======
-Copyright 2011 David Zwarg <U{dzwarg@azavea.com}>
+Copyright 2011-2012 David Zwarg <U{dzwarg@azavea.com}>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -20,9 +20,9 @@
 
 @author: David Zwarg
 @contact: dzwarg@azavea.com
-@copyright: 2011, Azavea
+@copyright: 2011-2012, Azavea
 @license: Apache 2.0
-@version: 1.0.7
+@version: 1.0.9
 """
 import unittest, sys, logging
 from optparse import OptionParser

diff --git a/sld/test/__init__.py b/sld/test/__init__.py
@@ -3,7 +3,7 @@
 
 License
 =======
-Copyright 2011 David Zwarg <U{dzwarg@azavea.com}>
+Copyright 2011-2012 David Zwarg <U{dzwarg@azavea.com}>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -19,9 +19,9 @@
 
 @author: David Zwarg
 @contact: dzwarg@azavea.com
-@copyright: 2011, Azavea
+@copyright: 2011-2012, Azavea
 @license: Apache 2.0
-@version: 1.0.8
+@version: 1.0.9
 """
 from sld import *
 import unittest, copy