from types import StringTypes
from lxml import etree
from StringIO import StringIO
-
from sfa.util.faults import InvalidXML
+from sfa.rspecs.elements.element import Element
+# helper functions to help build xpaths
class XpathFilter:
@staticmethod
- def xpath(filter={}):
+
+ def filter_value(key, value):
+ xpath = ""
+ if isinstance(value, str):
+ if '*' in value:
+ value = value.replace('*', '')
+ xpath = 'contains(%s, "%s")' % (key, value)
+ else:
+ xpath = '%s="%s"' % (key, value)
+ return xpath
+
+ @staticmethod
+ def xpath(filter=None):
+ if filter is None: filter={}
xpath = ""
if filter:
filter_list = []
else:
key = '@'+key
if isinstance(value, str):
- filter_list.append('%s="%s"' % (key, value))
+ filter_list.append(XpathFilter.filter_value(key, value))
elif isinstance(value, list):
- filter_list.append('contains("%s", %s)' % (' '.join(map(str, value)), key))
+ stmt = ' or '.join([XpathFilter.filter_value(key, str(val)) for val in value])
+ filter_list.append(stmt)
if filter_list:
xpath = ' and '.join(filter_list)
xpath = '[' + xpath + ']'
return xpath
+# a wrapper class around lxml.etree._Element
+# the reason why we need this one is because of the limitations
+# we've found in xpath to address documents with multiple namespaces defined
+# in a nutshell, we deal with xml documents that have
+# a default namespace defined (xmlns="http://default.com/") and specific prefixes defined
+# (xmlns:foo="http://foo.com")
+# according to the documentation instead of writing
+# element.xpath ( "//node/foo:subnode" )
+# we'd then need to write xpaths like
+# element.xpath ( "//{http://default.com/}node/{http://foo.com}subnode" )
+# which is a real pain..
+# So just so we can keep some reasonable programming style we need to manage the
+# namespace map that goes with the _Element (its internal .nsmap being unmutable)
+
+class XmlElement:
+ def __init__(self, element, namespaces):
+ self.element = element
+ self.namespaces = namespaces
+
+ # redefine as few methods as possible
+ def xpath(self, xpath, namespaces=None):
+ if not namespaces:
+ namespaces = self.namespaces
+ elems = self.element.xpath(xpath, namespaces=namespaces)
+ return [XmlElement(elem, namespaces) for elem in elems]
+
+ def add_element(self, tagname, **kwds):
+ element = etree.SubElement(self.element, tagname, **kwds)
+ return XmlElement(element, self.namespaces)
+
+ def append(self, elem):
+ if isinstance(elem, XmlElement):
+ self.element.append(elem.element)
+ else:
+ self.element.append(elem)
+
+ def getparent(self):
+ return XmlElement(self.element.getparent(), self.namespaces)
+
+ def get_instance(self, instance_class=None, fields=None):
+ """
+ Returns an instance (dict) of this xml element. The instance
+ holds a reference to this xml element.
+ """
+ if fields is None: fields=[]
+ if not instance_class:
+ instance_class = Element
+ if not fields and hasattr(instance_class, 'fields'):
+ fields = instance_class.fields
+
+ if not fields:
+ instance = instance_class(self.attrib, self)
+ else:
+ instance = instance_class({}, self)
+ for field in fields:
+ if field in self.attrib:
+ instance[field] = self.attrib[field]
+ return instance
+
+ def add_instance(self, name, instance, fields=None):
+ """
+ Adds the specifed instance(s) as a child element of this xml
+ element.
+ """
+ if fields is None: fields=[]
+ if not fields and hasattr(instance, 'keys'):
+ fields = instance.keys()
+ elem = self.add_element(name)
+ for field in fields:
+ if field in instance and instance[field]:
+ elem.set(field, unicode(instance[field]))
+ return elem
+
+ def remove_elements(self, name):
+ """
+ Removes all occurences of an element from the tree. Start at
+ specified root_node if specified, otherwise start at tree's root.
+ """
+
+ if not element_name.startswith('//'):
+ element_name = '//' + element_name
+ elements = self.element.xpath('%s ' % name, namespaces=self.namespaces)
+ for element in elements:
+ parent = element.getparent()
+ parent.remove(element)
+
+ def delete(self):
+ parent = self.getparent()
+ parent.remove(self)
+
+ def remove(self, element):
+ if isinstance(element, XmlElement):
+ self.element.remove(element.element)
+ else:
+ self.element.remove(element)
+
+ def set_text(self, text):
+ self.element.text = text
+
+ # Element does not have unset ?!?
+ def unset(self, key):
+ del self.element.attrib[key]
+
+ def toxml(self):
+ return etree.tostring(self.element, encoding='UTF-8', pretty_print=True)
+
+ def __str__(self):
+ return self.toxml()
+
+ ### other method calls or attribute access like .text or .tag or .get
+ # are redirected on self.element
+ def __getattr__ (self, name):
+ if not hasattr(self.element, name):
+ raise AttributeError, name
+ return getattr(self.element, name)
+
class XML:
- def __init__(self, xml=None):
+ def __init__(self, xml=None, namespaces=None):
self.root = None
- self.namespaces = None
+ self.namespaces = namespaces
self.default_namespace = None
self.schema = None
if isinstance(xml, basestring):
self.parse_xml(xml)
- elif isinstance(xml, etree._ElementTree):
- self.root = xml.getroot()
- elif isinstance(xml, etree._Element):
- self.root = xml
+ if isinstance(xml, XmlElement):
+ self.root = xml
+ self.namespaces = xml.namespaces
+ elif isinstance(xml, etree._ElementTree) or isinstance(xml, etree._Element):
+ self.parse_xml(etree.tostring(xml))
def parse_xml(self, xml):
"""
tree = etree.parse(StringIO(xml), parser)
except Exception, e:
raise InvalidXML(str(e))
- self.root = tree.getroot()
+ root = tree.getroot()
+ self.namespaces = dict(root.nsmap)
# set namespaces map
- self.namespaces = dict(self.root.nsmap)
if 'default' not in self.namespaces and None in self.namespaces:
# If the 'None' exist, then it's pointing to the default namespace. This makes
# it hard for us to write xpath queries for the default naemspace because lxml
# wont understand a None prefix. We will just associate the default namespeace
# with a key named 'default'.
- self.namespaces['default'] = self.namespaces[None]
+ self.namespaces['default'] = self.namespaces.pop(None)
+
else:
self.namespaces['default'] = 'default'
- # set schema
+ self.root = XmlElement(root, self.namespaces)
+ # set schema
for key in self.root.attrib.keys():
if key.endswith('schemaLocation'):
- # schema location should be at the end of the list
- schema_parts = self.root.attrib[key].split(' ')
+ # schemaLocation should be at the end of the list.
+ # Use list comprehension to filter out empty strings
+ schema_parts = [x for x in self.root.attrib[key].split(' ') if x]
self.schema = schema_parts[1]
namespace, schema = schema_parts[0], schema_parts[1]
break
if element is None:
if self.root is None:
self.parse_xml('<%s/>' % root_tag_name)
- element = self.root
+ element = self.root.element
if 'text' in d:
text = d.pop('text')
self.parse_dict(val, key, child_element)
elif isinstance(val, basestring):
child_element = etree.SubElement(element, key).text = val
-
+
elif isinstance(value, int):
- d[key] = unicode(d[key])
+ d[key] = unicode(d[key])
elif value is None:
d.pop(key)
def set(self, key, value):
return self.root.set(key, value)
- def add_attribute(self, elem, name, value):
- """
- Add attribute to specified etree element
- """
- opt = etree.SubElement(elem, name)
- opt.text = value
+ def remove_attribute(self, name, element=None):
+ if not element:
+ element = self.root
+ element.remove_attribute(name)
- def add_element(self, name, attrs={}, parent=None, text=""):
+ def add_element(self, *args, **kwds):
"""
Wrapper around etree.SubElement(). Adds an element to
specified parent node. Adds element to root node is parent is
not specified.
"""
- if parent == None:
- parent = self.root
- element = etree.SubElement(parent, name)
- if text:
- element.text = text
- if isinstance(attrs, dict):
- for attr in attrs:
- element.set(attr, attrs[attr])
- return element
+ return self.root.add_element(*args, **kwds)
- def remove_attribute(self, elem, name, value):
- """
- Removes an attribute from an element
- """
- if elem is not None:
- opts = elem.iterfind(name)
- if opts is not None:
- for opt in opts:
- if opt.text == value:
- elem.remove(opt)
-
- def remove_element(self, element_name, root_node = None):
+ def remove_elements(self, name, element = None):
"""
Removes all occurences of an element from the tree. Start at
specified root_node if specified, otherwise start at tree's root.
"""
- if not root_node:
- root_node = self.root
+ if not element:
+ element = self.root
- if not element_name.startswith('//'):
- element_name = '//' + element_name
+ element.remove_elements(name)
- elements = root_node.xpath('%s ' % element_name, namespaces=self.namespaces)
- for element in elements:
- parent = element.getparent()
- parent.remove(element)
+ def add_instance(self, *args, **kwds):
+ return self.root.add_instance(*args, **kwds)
- def attributes_list(self, elem):
- # convert a list of attribute tags into list of tuples
- # (tagnme, text_value)
- opts = []
- if elem is not None:
- for e in elem:
- opts.append((e.tag, str(e.text).strip()))
- return opts
+ def get_instance(self, *args, **kwds):
+ return self.root.get_instnace(*args, **kwds)
def get_element_attributes(self, elem=None, depth=0):
if elem == None:
- elem = self.root_node
+ elem = self.root
if not hasattr(elem, 'attrib'):
# this is probably not an element node with attribute. could be just and an
# attribute, return it
attrs['child_nodes'] = list(elem)
return attrs
+ def append(self, elem):
+ return self.root.append(elem)
+
+ def iterchildren(self):
+ return self.root.iterchildren()
+
def merge(self, in_xml):
pass
return self.toxml()
def toxml(self):
- return etree.tostring(self.root, encoding='UTF-8', pretty_print=True)
+ return etree.tostring(self.root.element, encoding='UTF-8', pretty_print=True)
# XXX smbaker, for record.load_from_string
def todict(self, elem=None):