3 from StringIO import StringIO
4 from datetime import datetime, timedelta
5 from sfa.util.xrn import *
6 from sfa.util.plxrn import hostname_to_urn
7 from sfa.util.config import Config
8 from sfa.util.faults import SfaNotImplemented, InvalidRSpec
11 header = '<?xml version="1.0"?>\n'
12 template = """<RSpec></RSpec>"""
18 def __init__(self, rspec="", namespaces={}):
20 self.parse_rspec(rspec, namespaces)
24 def create(self, type="advertisement"):
28 # eg. 2011-03-23T19:53:28Z
29 date_format = '%Y-%m-%dT%H:%M:%SZ'
30 now = datetime.utcnow()
31 generated_ts = now.strftime(date_format)
32 expires_ts = (now + timedelta(hours=1)).strftime(date_format)
33 self.parse_rspec(self.template, self.namespaces)
34 self.xml.set('valid_until', expires_ts)
35 self.xml.set('generated', generated_ts)
37 def parse_rspec(self, rspec, namespaces={}):
39 parse rspec into etree
41 parser = etree.XMLParser(remove_blank_text=True)
43 tree = etree.parse(rspec, parser)
45 # 'rspec' file doesnt exist. 'rspec' is proably an xml string
47 tree = etree.parse(StringIO(rspec), parser)
49 raise InvalidRSpec('Must specify a xml file or xml string. Received: ' + rspec )
51 self.xml = tree.getroot()
53 self.namespaces = namespaces
55 def add_attribute(self, elem, name, value):
57 Add attribute to specified etree element
59 opt = etree.SubElement(elem, name)
62 def add_element(self, name, attrs={}, parent=None, text=""):
64 Generic wrapper around etree.SubElement(). Adds an element to
65 specified parent node. Adds element to root node is parent is
70 element = etree.SubElement(parent, name)
73 if isinstance(attrs, dict):
75 element.set(attr, attrs[attr])
78 def remove_attribute(self, elem, name, value):
80 Removes an attribute from an element
83 opts = elem.iterfind(name)
90 def validate(self, schema):
92 Validate against rng schema
95 relaxng_doc = etree.parse(schema)
96 relaxng = etree.RelaxNG(relaxng_doc)
97 if not relaxng(self.xml):
98 error = relaxng.error_log.last_error
99 message = "%s (line %s)" % (error.message, error.line)
100 raise InvalidRSpec(message)
108 return self.header + etree.tostring(self.xml, pretty_print=True)
110 def save(self, filename):
111 f = open(filename, 'w')
112 f.write(self.toxml())
115 if __name__ == '__main__':