root / ncclient / xml_.py @ bbd4ce54
History | View | Annotate | Download (7.1 kB)
1 |
# Copyright 2009 Shikhar Bhushan
|
---|---|
2 |
#
|
3 |
# Licensed under the Apache License, Version 2.0 (the "License");
|
4 |
# you may not use this file except in compliance with the License.
|
5 |
# You may obtain a copy of the License at
|
6 |
#
|
7 |
# http://www.apache.org/licenses/LICENSE-2.0
|
8 |
#
|
9 |
# Unless required by applicable law or agreed to in writing, software
|
10 |
# distributed under the License is distributed on an "AS IS" BASIS,
|
11 |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
12 |
# See the License for the specific language governing permissions and
|
13 |
# limitations under the License.
|
14 |
|
15 |
|
16 |
"""The :mod:`xml` module provides methods for creating XML documents, parsing
|
17 |
XML, and converting between different XML representations. It uses
|
18 |
:mod:`~xml.etree.ElementTree` internally.
|
19 |
"""
|
20 |
|
21 |
from cStringIO import StringIO |
22 |
from xml.etree import cElementTree as ET |
23 |
|
24 |
from ncclient import NCClientError |
25 |
|
26 |
class ContentError(NCClientError): |
27 |
"Raised by methods of the :mod:`content` module in case of an error."
|
28 |
pass
|
29 |
|
30 |
### Namespace-related
|
31 |
|
32 |
#: Base NETCONF namespace
|
33 |
BASE_NS = 'urn:ietf:params:xml:ns:netconf:base:1.0'
|
34 |
#: ... and this is BASE_NS according to Cisco devices tested
|
35 |
CISCO_BS = 'urn:ietf:params:netconf:base:1.0'
|
36 |
#: namespace for Tail-f data model
|
37 |
TAILF_AAA_1_1 = 'http://tail-f.com/ns/aaa/1.1'
|
38 |
#: namespace for Tail-f data model
|
39 |
TAILF_EXECD_1_1 = 'http://tail-f.com/ns/execd/1.1'
|
40 |
#: namespace for Cisco data model
|
41 |
CISCO_CPI_10 = 'http://www.cisco.com/cpi_10/schema'
|
42 |
|
43 |
try:
|
44 |
register_namespace = ET.register_namespace |
45 |
except AttributeError: |
46 |
def register_namespace(prefix, uri): |
47 |
from xml.etree import ElementTree |
48 |
# cElementTree uses ElementTree's _namespace_map, so that's ok
|
49 |
ElementTree._namespace_map[uri] = prefix |
50 |
|
51 |
register_namespace('netconf', BASE_NS)
|
52 |
register_namespace('aaa', TAILF_AAA_1_1)
|
53 |
register_namespace('execd', TAILF_EXECD_1_1)
|
54 |
register_namespace('cpi', CISCO_CPI_10)
|
55 |
|
56 |
|
57 |
qualify = lambda tag, ns=BASE_NS: tag if ns is None else '{%s}%s' % (ns, tag) |
58 |
|
59 |
#: Deprecated
|
60 |
multiqualify = lambda tag, nslist=(BASE_NS, CISCO_BS): [qualify(tag, ns) for ns in nslist] |
61 |
|
62 |
unqualify = lambda tag: tag[tag.rfind('}')+1:] |
63 |
|
64 |
### XML with Python data structures
|
65 |
|
66 |
class DictTree: |
67 |
|
68 |
@staticmethod
|
69 |
def Element(spec): |
70 |
"""DictTree -> Element
|
71 |
|
72 |
:type spec: :obj:`dict` or :obj:`string` or :class:`~xml.etree.ElementTree.Element`
|
73 |
|
74 |
:rtype: :class:`~xml.etree.ElementTree.Element`
|
75 |
"""
|
76 |
if iselement(spec):
|
77 |
return spec
|
78 |
elif isinstance(spec, basestring): |
79 |
return XML.Element(spec)
|
80 |
if not isinstance(spec, dict): |
81 |
raise ContentError("Invalid tree spec") |
82 |
if 'tag' in spec: |
83 |
ele = ET.Element(spec.get('tag'), spec.get('attrib', {})) |
84 |
ele.text = spec.get('text', '') |
85 |
ele.tail = spec.get('tail', '') |
86 |
subtree = spec.get('subtree', [])
|
87 |
# might not be properly specified as list but may be dict
|
88 |
if not isinstance(subtree, list): |
89 |
subtree = [subtree] |
90 |
for subele in subtree: |
91 |
ele.append(DictTree.Element(subele)) |
92 |
return ele
|
93 |
elif 'comment' in spec: |
94 |
return ET.Comment(spec.get('comment')) |
95 |
else:
|
96 |
raise ContentError('Invalid tree spec') |
97 |
|
98 |
@staticmethod
|
99 |
def XML(spec, encoding='UTF-8'): |
100 |
"""DictTree -> XML
|
101 |
|
102 |
:type spec: :obj:`dict` or :obj:`string` or :class:`~xml.etree.ElementTree.Element`
|
103 |
|
104 |
:arg encoding: chraracter encoding
|
105 |
|
106 |
:rtype: string
|
107 |
"""
|
108 |
return Element.XML(DictTree.Element(spec), encoding)
|
109 |
|
110 |
class Element: |
111 |
|
112 |
@staticmethod
|
113 |
def DictTree(ele): |
114 |
"""DictTree -> Element
|
115 |
|
116 |
:type spec: :class:`~xml.etree.ElementTree.Element`
|
117 |
:rtype: :obj:`dict`
|
118 |
"""
|
119 |
return {
|
120 |
'tag': ele.tag,
|
121 |
'attributes': ele.attrib,
|
122 |
'text': ele.text,
|
123 |
'tail': ele.tail,
|
124 |
'subtree': [ Element.DictTree(child) for child in ele.getchildren() ] |
125 |
} |
126 |
|
127 |
@staticmethod
|
128 |
def XML(ele, encoding='UTF-8'): |
129 |
"""Element -> XML
|
130 |
|
131 |
:type spec: :class:`~xml.etree.ElementTree.Element`
|
132 |
:arg encoding: character encoding
|
133 |
:rtype: :obj:`string`
|
134 |
"""
|
135 |
xml = ET.tostring(ele, encoding) |
136 |
if xml.startswith('<?xml'): |
137 |
return xml
|
138 |
else:
|
139 |
return '<?xml version="1.0" encoding="%s"?>%s' % (encoding, xml) |
140 |
|
141 |
class XML: |
142 |
|
143 |
@staticmethod
|
144 |
def DictTree(xml): |
145 |
"""XML -> DictTree
|
146 |
|
147 |
:type spec: :obj:`string`
|
148 |
:rtype: :obj:`dict`
|
149 |
"""
|
150 |
return Element.DictTree(XML.Element(xml))
|
151 |
|
152 |
@staticmethod
|
153 |
def Element(xml): |
154 |
"""XML -> Element
|
155 |
|
156 |
:type xml: :obj:`string`
|
157 |
:rtype: :class:`~xml.etree.ElementTree.Element`
|
158 |
"""
|
159 |
return ET.fromstring(xml)
|
160 |
|
161 |
dtree2ele = DictTree.Element |
162 |
dtree2xml = DictTree.XML |
163 |
ele2dtree = Element.DictTree |
164 |
ele2xml = Element.XML |
165 |
xml2dtree = XML.DictTree |
166 |
xml2ele = XML.Element |
167 |
|
168 |
### Other utility functions
|
169 |
|
170 |
iselement = ET.iselement |
171 |
|
172 |
def find(ele, tag, nslist=[]): |
173 |
"""If *nslist* is empty, same as :meth:`xml.etree.ElementTree.Element.find`.
|
174 |
If it is not, *tag* is interpreted as an unqualified name and qualified
|
175 |
using each item in *nslist* (with a :const:`None` item in *nslit* meaning no
|
176 |
qualification is done). The first match is returned.
|
177 |
|
178 |
:arg nslist: optional list of namespaces
|
179 |
:type nslit: `string` `list`
|
180 |
"""
|
181 |
if nslist:
|
182 |
for qname in multiqualify(tag): |
183 |
found = ele.find(qname) |
184 |
if found is not None: |
185 |
return found
|
186 |
else:
|
187 |
return ele.find(tag)
|
188 |
|
189 |
def parse_root(raw): |
190 |
"""Efficiently parses the root element of an XML document.
|
191 |
|
192 |
:arg raw: XML document
|
193 |
:type raw: string
|
194 |
:returns: a tuple of `(tag, attributes)`, where `tag` is the (qualified) name of the element and `attributes` is a dictionary of its attributes.
|
195 |
:rtype: `tuple`
|
196 |
"""
|
197 |
fp = StringIO(raw[:1024]) # this is a guess but start element beyond 1024 bytes would be a bit absurd |
198 |
for event, element in ET.iterparse(fp, events=('start',)): |
199 |
return (element.tag, element.attrib)
|
200 |
|
201 |
def validated_element(rep, tags=None, attrs=None, text=None): |
202 |
"""Checks if the root element meets the supplied criteria. Returns a
|
203 |
:class:`~xml.etree.ElementTree.Element` instance if so, otherwise raises
|
204 |
:exc:`ContentError`.
|
205 |
|
206 |
:arg tags: tag name or a list of allowable tag names
|
207 |
:arg attrs: list of required attribute names, each item may be a list of allowable alternatives
|
208 |
:arg text: textual content to match
|
209 |
:type rep: :obj:`dict` or :obj:`string` or :class:`~xml.etree.ElementTree.Element`
|
210 |
"""
|
211 |
ele = dtree2ele(rep) |
212 |
err = False
|
213 |
if tags:
|
214 |
if isinstance(tags, basestring): |
215 |
tags = [tags] |
216 |
if ele.tag not in tags: |
217 |
err = True
|
218 |
if attrs:
|
219 |
for req in attrs: |
220 |
if isinstance(req, basestring): req = [req] |
221 |
for alt in req: |
222 |
if alt in ele.attrib: |
223 |
break
|
224 |
else:
|
225 |
err = True
|
226 |
if text and ele.text != text: |
227 |
err = True
|
228 |
if err:
|
229 |
raise ContentError("Element [%s] does not meet requirements" % ele.tag) |
230 |
return ele
|