src/PyCIM/xmlpp.py

   1 """Pretty print an XML document.
   2
   3 LICENCE:
   4 Copyright (c) 2008, Fredrik Ekholdt
   5 All rights reserved.
   6
   7 Redistribution and use in source and binary forms, with or without
   8 modification, are permitted provided that the following conditions are met:
   9
  10 * Redistributions of source code must retain the above copyright notice,
  11 this list of conditions and the following disclaimer.
  12
  13 * Redistributions in binary form must reproduce the above copyright notice,
  14 this list of conditions and the following disclaimer in the documentation
  15 and/or other materials provided with the distribution.
  16
  17 * Neither the name of Fredrik Ekholdt nor the names of its contributors may be used to
  18 endorse or promote products derived from this software without specific prior
  19 written permission.
  20
  21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  22 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  25 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31 POSSIBILITY OF SUCH DAMAGE."""
  32
  33 import sys as _sys
  34 import re as _re
  35
  36 def _usage(this_file):
  37     return """SYNOPSIS: pretty print an XML document
  38 USAGE: python %s <filename> \n""" % this_file
  39
  40 def _pprint_line(indent_level, line, width=100, output=_sys.stdout):
  41     if line.strip():
  42         start = ""
  43         number_chars = 0
  44         for l in range(indent_level):
  45             start = start + " "
  46             number_chars = number_chars + 1
  47         try:
  48             elem_start = _re.findall("(\<\W{0,1}\w+:\w+) ?", line)[0]
  49             elem_finished = _re.findall("([?|\]\]/]*\>)", line)[0]
  50             #should not have *
  51             attrs = _re.findall("(\S*?\=\".*?\")", line)
  52             output.write(start + elem_start)
  53             number_chars = len(start + elem_start)
  54             for attr in attrs:
  55                 if (attrs.index(attr) + 1) == len(attrs):
  56                     number_chars = number_chars + len(elem_finished)
  57                 if (number_chars + len(attr) + 1) > width:
  58                     output.write("\n")
  59                     for i in range(len(start + elem_start) + 1):
  60                         output.write(" ")
  61                     number_chars = len(start + elem_start) + 1
  62                 else:
  63                     output.write(" ")
  64                     number_chars = number_chars + 1
  65                 output.write(attr)
  66                 number_chars = number_chars + len(attr)
  67             output.write(elem_finished + "\n")
  68         except IndexError:
  69             #give up pretty print this line
  70             output.write(start + line + "\n")
  71
  72
  73 def _pprint_elem_content(indent_level, line, output=_sys.stdout):
  74     if line.strip():
  75         for l in range(indent_level):
  76             output.write(" ")
  77         output.write(line + "\n")
  78
  79 def _get_next_elem(data):
  80     start_pos = data.find("<")
  81     end_pos = data.find(">") + 1
  82     retval = data[start_pos:end_pos]
  83     stopper = retval.rfind("/")
  84     if stopper < retval.rfind("\""):
  85         stopper = -1
  86     single = (stopper > -1 and ((retval.find(">") - stopper) < (stopper - retval.find("<"))))
  87
  88     ignore_excl = retval.find("<!") > -1
  89     ignore_question =  retval.find("<?") > -1
  90
  91     if ignore_excl:
  92         cdata = retval.find("<![CDATA[") > -1
  93         if cdata:
  94             end_pos = data.find("]]>")
  95             if end_pos > -1:
  96                 end_pos = end_pos + len("]]>")
  97
  98     elif ignore_question:
  99         end_pos = data.find("?>") + len("?>")
 100     ignore = ignore_excl or ignore_question
 101
 102     no_indent = ignore or single
 103
 104     #print retval, end_pos, start_pos, stopper > -1, no_indent
 105     return start_pos, \
 106            end_pos, \
 107            stopper > -1, \
 108            no_indent
 109
 110 def get_pprint(xml, indent=4, width=80):
 111     """Returns the pretty printed xml """
 112     class out:
 113         output = ""
 114
 115         def write(self, string):
 116             self.output += string
 117     out = out()
 118     pprint(xml, output=out, indent=indent, width=width)
 119
 120     return out.output
 121
 122
 123 def pprint(xml, output=_sys.stdout, indent=4, width=80):
 124     """Pretty print xml.
 125     Use output to select output stream. Default is sys.stdout
 126     Use indent to select indentation level. Default is 4   """
 127     data = xml
 128     indent_level = 0
 129     start_pos, end_pos, is_stop, no_indent  = _get_next_elem(data)
 130     while ((start_pos > -1 and end_pos > -1)):
 131         _pprint_elem_content(indent_level, data[:start_pos].strip(),
 132                              output=output)
 133         data = data[start_pos:]
 134         if is_stop and not no_indent:
 135             indent_level = indent_level - indent
 136         _pprint_line(indent_level,
 137                      data[:end_pos - start_pos],
 138                      width=width,
 139                      output=output)
 140         data = data[end_pos - start_pos:]
 141         if not is_stop and not no_indent :
 142             indent_level = indent_level + indent
 143
 144         if not data:
 145             break
 146         else:
 147             start_pos, end_pos, is_stop, no_indent  = _get_next_elem(data)
 148
 149
 150 if __name__ == "__main__":
 151     if "-h" in _sys.argv or "--help" in _sys.argv:
 152         _sys.stderr.write(_usage(_sys.argv[0]))
 153         _sys.exit(1)
 154     if len(_sys.argv) < 2:
 155         _sys.stderr.write(_usage(_sys.argv[0]))
 156         _sys.exit(1)
 157     else:
 158         filename = _sys.argv[1]
 159         fh = open(filename)
 160
 161     pprint(fh.read(), output=_sys.stdout, indent=4, width=80)