Source Code for Module backend.satellite_tools.exporter.xmlWriter

  1  # -*- coding: ISO-8859-1 -*- 
  2  # 
  3  # Copyright (c) 2008--2016 Red Hat, Inc. 
  4  # 
  5  # This software is licensed to you under the GNU General Public License, 
  6  # version 2 (GPLv2). There is NO WARRANTY for this software, express or 
  7  # implied, including the implied warranties of MERCHANTABILITY or FITNESS 
  8  # FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2 
  9  # along with this software; if not, see 
 10  # http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt. 
 11  # 
 12  # Red Hat trademarks are not licensed under GPLv2. No permission is 
 13  # granted to use or replicate Red Hat trademarks that are incorporated 
 14  # in this software or its documentation. 
 15  # 
 16  # UTF-8 aware XML writer 
 17  # 
 18   
 19  import re 
 20  import sys 
 21   
 22   
 23 -class XMLWriter: 
 24   
 25      """ 
 26      XML writer, UTF-8 aware 
 27      """ 
 28   
 29      # We escape &<>'" and chars UTF-8 does not properly escape (everything 
 30      # other than tab (\x09), newline and carriage return (\x0a and \x0d) and 
 31      # stuff above ASCII 32) 
 32      _re = re.compile("(&|<|>|'|\"|[^\x09\x0a\x0d\x20-\xFF])") 
 33      _escaped_chars = { 
 34          '&': '&amp;', 
 35          '<': '&lt;', 
 36          '>': '&gt;', 
 37          '"': '&quot;', 
 38          "'": '&apos;', 
 39      } 
 40   
 41 -    def __init__(self, stream=sys.stdout, skip_xml_decl=0): 
 42          self.tag_stack = [] 
 43          self.stream = stream 
 44          if not skip_xml_decl: 
 45              self.stream.write('<?xml version="1.0" encoding="UTF-8"?>') 
 46   
 47 -    def open_tag(self, name, attributes=None, namespace=None): 
 48          "Opens a tag with the specified attributes" 
 49          return self._open_tag(None, name, attributes=attributes, 
 50                                namespace=namespace) 
 51   
 52 -    def empty_tag(self, name, attributes=None, namespace=None): 
 53          "Writes an empty tag with the specified attributes" 
 54          return self._open_tag(1, name, attributes=attributes, 
 55                                namespace=namespace) 
 56   
 57      # Now the function that does most of the work for open_tag and empty_tag 
 58 -    def _open_tag(self, empty, name, attributes=None, namespace=None): 
 59          if namespace: 
 60              name = "%s:%s" % (namespace, name) 
 61          self.stream.write("<") 
 62          self.data(name) 
 63          # Dump the attributes, if any 
 64          if attributes: 
 65              for k, v in attributes.items(): 
 66                  self.stream.write(" ") 
 67                  self.data(k) 
 68                  self.stream.write('="') 
 69                  self.data(str(v)) 
 70                  self.stream.write('"') 
 71          if empty: 
 72              self.stream.write("/") 
 73          self.stream.write(">") 
 74   
 75          if not empty: 
 76              self.tag_stack.append(name) 
 77   
 78 -    def close_tag(self, name, namespace=None): 
 79          """ 
 80          Closes a previously open tag. 
 81          This function raises an exception if the tag was not opened before, or 
 82          if it's been closed already. 
 83          """ 
 84          if not self.tag_stack: 
 85              raise Exception("Could not close tag %s: empty tag stack" % name) 
 86          if namespace: 
 87              name = "%s:%s" % (namespace, name) 
 88   
 89          if self.tag_stack[-1] != name: 
 90              raise Exception("Could not close tag %s if not opened before" \ 
 91                  % name) 
 92          self.tag_stack.pop() 
 93   
 94          self.stream.write("</") 
 95          self.data(name) 
 96          self.stream.write(">") 
 97   
 98 -    def data(self, data_string): 
 99          """ 
100          Writes the data, performing the necessary UTF-8 conversions 
101          max_bytes is the satellite schema dependent maximum value (in bytes) 
102          which can fit in the matching table row. Yeah, this is very gross. 
103          """ 
104          if data_string is None: 
105              data_string = "" 
106          else: 
107              data_string = str(data_string) 
108   
109          data_string = self._re.sub(self._sub_function, data_string) 
110          self.stream.write(data_string) 
111   
112      # Helper functions 
113   
114      # Substitution function for re 
115 -    def _sub_function(self, match_object): 
116          c = match_object.group() 
117          if c in self._escaped_chars: 
118              return self._escaped_chars[c] 
119          # return "&#%d;" % ord(c) 
120          return '?' 
121   
122 -    def flush(self): 
123          self.stream.flush() 
124   
125  if __name__ == '__main__': 
126      weirdtag = chr(248) + 'gootag' 
127      writer = XMLWriter() 
128      writer.open_tag(weirdtag) 
129      writer.open_tag("message") 
130      writer.open_tag("text", attributes={'from': 'Trond Eivind Glomsrød', 'to': "Bernhard Rosenkr)Bänzer"}) 
131      writer.data("String with \"quotes\", 'apostroph', Trond Eivind Glomsrød\n  and Bernhard Rosenkr)Bänzer") 
132      r = re.compile("(&|<|>|'|\"|[^\x09\x0a\x0d\x20-\xFF])") 
133      writer.close_tag("text") 
134      writer.close_tag("message") 
135      writer.empty_tag("yahoo", attributes={'abc': 1}) 
136      writer.close_tag(weirdtag) 
137      print("") 
138