src/KML.py

   1 """
   2 Utility classes for working with the Keyhole Markup Language (KML).
   3 """
   4
   5 import sys
   6
   7
   8 class KmlObject(object):
   9     """
  10     The base class of all KML elements, according to the reference:
  11
  12       http://code.google.com/apis/kml/documentation/kmlreference.html
  13
  14     Every other class in this module should derive from
  15     KmlObject. This class provides a default constructor which creates
  16     some necessary attributes, and default implementations of to_kml()
  17     and render().
  18
  19     The to_kml() methods of our subclasses will, in general, generate
  20     an opening tag, render themselves (whatever that means), and then
  21     generate a closing tag. A call to render() generally returns the
  22     element's text, and renders its children recursively.
  23     """
  24
  25     OPEN_TAG = ''
  26     CLOSE_TAG = ''
  27
  28     def __init__(self, initial_text=''):
  29         self.children = []
  30         self.text = initial_text
  31
  32
  33     def to_kml(self):
  34         return self.render()
  35
  36
  37     def render(self):
  38         kml = self.OPEN_TAG
  39         kml += self.text
  40
  41         for c in self.children:
  42             kml += c.to_kml()
  43
  44         kml += self.CLOSE_TAG + "\n"
  45
  46         return kml
  47
  48
  49     def print_kml(self):
  50         print self.OPEN_TAG
  51         self.render_to_stdout()
  52         print self.CLOSE_TAG
  53
  54
  55     def render_to_stdout(self):
  56         if not (len(self.text) == 0):
  57             print self.text
  58
  59         for c in self.children:
  60             c.print_kml()
  61
  62
  63
  64 class Color(KmlObject):
  65
  66     OPEN_TAG = '<color>'
  67     CLOSE_TAG = '</color>'
  68
  69
  70 class Document(KmlObject):
  71
  72     OPEN_TAG = """<?xml version=\"1.0\" encoding=\"UTF-8\"?>
  73 <kml xmlns=\"http://www.opengis.net/kml/2.2\">
  74 <Document>"""
  75
  76     CLOSE_TAG = """</Document>
  77     </kml>"""
  78
  79     def __init__(self, initial_text=''):
  80         super(Document, self).__init__(initial_text)
  81         self.styles = []
  82
  83
  84     def render(self):
  85         kml = ''
  86
  87         for s in self.styles:
  88             kml += s.to_kml()
  89
  90         for c in self.children:
  91             kml += c.to_kml()
  92
  93         return kml
  94
  95
  96     def render_to_stdout(self):
  97         for s in self.styles:
  98             s.print_kml()
  99
 100         for c in self.children:
 101             c.print_kml()
 102
 103
 104
 105 class Description(KmlObject):
 106
 107     OPEN_TAG = '<description>'
 108     CLOSE_TAG = '</description>'
 109
 110
 111
 112 class Name(KmlObject):
 113
 114     OPEN_TAG = '<name>'
 115     CLOSE_TAG = '</name>'
 116
 117
 118
 119 class Placemark(KmlObject):
 120
 121     OPEN_TAG = '<Placemark>'
 122     CLOSE_TAG = '</Placemark>'
 123
 124
 125
 126 class PolyStyle(KmlObject):
 127
 128     OPEN_TAG = '<PolyStyle>'
 129     CLOSE_TAG = '</PolyStyle>'
 130
 131
 132
 133 class Style(KmlObject):
 134
 135     OPEN_TAG = "<Style id=\"%s\">"
 136     CLOSE_TAG = '</Style>'
 137
 138     def __init__(self, initial_text='', initial_id=''):
 139         super(Style, self).__init__(initial_text)
 140         self.id = initial_id
 141
 142
 143     def to_kml(self):
 144         kml = ''
 145         kml += (self.OPEN_TAG % self.id + "\n")
 146         kml += self.render()
 147         kml += self.CLOSE_TAG + "\n"
 148
 149         return kml
 150
 151
 152     def print_kml(self):
 153         print (self.OPEN_TAG % self.id)
 154         self.render_to_stdout()
 155         print self.CLOSE_TAG
 156
 157
 158
 159 class StyleUrl(KmlObject):
 160
 161     OPEN_TAG = '<styleUrl>'
 162     CLOSE_TAG = '</styleUrl>'
 163
 164
 165
 166 class RawText(KmlObject):
 167     pass