Update issue 120

Moving parsers and serializer implementations into rdflib.plugins package

1 files changed, 102 insertions, 0 deletions

diff --git a/rdflib/plugins/serializers/xmlwriter.py b/rdflib/plugins/serializers/xmlwriter.py
new file mode 100644
index 00000000..5d15f4b7
--- /dev/null
+++ b/rdflib/plugins/serializers/xmlwriter.py
@@ -0,0 +1,102 @@
+import codecs
+from xml.sax.saxutils import quoteattr, escape
+
+
+class XMLWriter(object):
+    def __init__(self, stream, namespace_manager, encoding=None, decl=1, extra_ns={}):
+        encoding = encoding or 'utf-8'
+        encoder, decoder, stream_reader, stream_writer = codecs.lookup(encoding)
+        self.stream = stream = stream_writer(stream)
+        if decl:
+            stream.write('<?xml version="1.0" encoding="%s"?>' % encoding)
+        self.element_stack = []
+        self.nm = namespace_manager
+        self.extra_ns=extra_ns
+        self.closed = True
+
+    def __get_indent(self):
+        return "  " * len(self.element_stack)
+    indent = property(__get_indent)
+
+    def __close_start_tag(self):
+        if not self.closed: # TODO:
+            self.closed = True
+            self.stream.write(">")
+
+    def push(self, uri):
+        self.__close_start_tag()
+        write = self.stream.write
+        write("\n")
+        write(self.indent)
+        write("<%s" % self.qname(uri))
+        self.element_stack.append(uri)
+        self.closed = False
+        self.parent = False
+
+    def pop(self, uri=None):
+        top = self.element_stack.pop()
+        if uri:
+            assert uri == top
+        write = self.stream.write
+        if not self.closed:
+            self.closed = True
+            write("/>")
+        else:
+            if self.parent:
+                write("\n")
+                write(self.indent)
+            write("</%s>" % self.qname(top))
+        self.parent = True
+
+    def element(self, uri, content, attributes={}):
+        """Utility method for adding a complete simple element"""
+        self.push(uri)
+        for k, v in attributes.iteritems():
+            self.attribute(k,v)
+        self.text(content)
+        self.pop()
+
+    def namespaces(self, namespaces=None):
+        if not namespaces:
+            namespaces=self.nm.namespaces()
+
+        write = self.stream.write
+        write("\n")
+        for prefix, namespace in namespaces:
+            if prefix:
+                write('  xmlns:%s="%s"\n' % (prefix, namespace))
+            else:
+                write('  xmlns="%s"\n' % namespace)
+
+        for prefix, namespace in self.extra_ns.items():
+            if prefix:
+                write('  xmlns:%s="%s"\n' % (prefix, namespace))
+            else:
+                write('  xmlns="%s"\n' % namespace)
+
+
+    def attribute(self, uri, value):
+        write = self.stream.write
+        write(" %s=%s" % (self.qname(uri), quoteattr(value)))
+
+    def text(self, text):
+        self.__close_start_tag()
+        if "<" in text and ">" in text and not "]]>" in text:
+            self.stream.write("<![CDATA[")
+            self.stream.write(text)
+            self.stream.write("]]>")
+        else:
+            self.stream.write(escape(text))
+
+    def qname(self,uri): 
+        """Compute qname for a uri using our extra namespaces,
+        or the given namespace manager"""
+
+        for pre,ns in self.extra_ns.items(): 
+            if uri.startswith(ns): 
+                if pre!="": 
+                    return ":".join(pre,uri[len(ns):])
+                else: 
+                    return uri[len(ns):]
+
+        return self.nm.qname(uri)