Pull XML namespaces and so forth from schemas where possible.

svn path=/trunk/; revision=5902

1 files changed, 42 insertions, 0 deletions

diff --git a/rpki/relaxng_parser.py b/rpki/relaxng_parser.py
new file mode 100644
index 00000000..466b1a79
--- /dev/null
+++ b/rpki/relaxng_parser.py
@@ -0,0 +1,42 @@
+# $Id$
+#
+# Copyright (C) 2014  Dragon Research Labs ("DRL")
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND DRL DISCLAIMS ALL WARRANTIES WITH
+# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS.  IN NO EVENT SHALL DRL BE LIABLE FOR ANY SPECIAL, DIRECT,
+# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
+
+"""
+Wrapper around lxml to extract various useful data and methods
+from an XML-format RelaxNG schema.
+"""
+
+import lxml.etree
+
+class RelaxNGParser(object):
+  """
+  Parse schema, extract XML namespace and protocol version (if any).
+  Method calls are just passed along to the parsed RelaxNG schema.
+  """
+
+  def __init__(self, text):
+    xml = lxml.etree.fromstring(text)
+    self.schema = lxml.etree.RelaxNG(xml)
+    ns = xml.get("ns")
+    self.xmlns = "{" + ns + "}"
+    self.nsmap = { None : ns }
+    x = xml.xpath("ns0:define[@name = 'version']/ns0:value",
+                  namespaces = dict(ns0 = "http://relaxng.org/ns/structure/1.0"))
+    if len(x) == 1:
+      self.version = x[0].text
+
+  def __getattr__(self, name):
+    return getattr(self.schema, name)