Thuban/Model/xmlwriter.py

# Copyright (c) 2003 by Intevation GmbH
# Authors:
# Jonathan Coles <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with Thuban for details.

"""
Functions to save an XML file
"""

__version__ = "$Revision$"

import os
from types import UnicodeType

#
# one level of indention
#
TAB = "    "

def escape(data):
    """Escape &, \", ', <, and > in a string of data.
    """
    data = data.replace("&", "&amp;")
    data = data.replace("<", "&lt;")
    data = data.replace(">", "&gt;")
    data = data.replace('"', "&quot;")
    data = data.replace("'", "&apos;")
    return data

class XMLWriter:
    """Abstract XMLWriter.

    Should be overridden to provide specific object saving functionality.
    """

    def __init__(self):
        self.filename = None
        pass

    def write(self, file_or_filename):
        """Write the session to a file.

        The argument may be either a file object or a filename. If it's
        a filename, the file will be opened for writing. Files of
        shapefiles will be stored as filenames relative to the directory
        the file is stored in (as given by os.path.dirname(filename)) if
        they have a common parent directory other than the root
        directory.

        If the argument is a file object (which is determined by the
        presence of a write method) all filenames will be absolute
        filenames.
        """

        # keep track of how many levels of indentation to write
        self.indent_level = 0 
        # track whether an element is currently open. see open_element().
        self.element_open = 0

        if hasattr(file_or_filename, "write"):
            # it's a file object
            self.file = file_or_filename
            self.dir = ""
        else:
            self.filename = file_or_filename
            self.dir = os.path.dirname(self.filename)
            self.file = open(self.filename, 'w')

    def close(self):
        assert self.indent_level == 0
        if self.filename is not None:
            self.file.close()

    def write_header(self, doctype, system):
        """Write the XML header"""
        self.file.write('<?xml version="1.0" encoding="UTF-8"?>\n')
        self.file.write('<!DOCTYPE %s SYSTEM "%s">\n' % (doctype, system))

    def open_element(self, element, attrs = {}):

        #
        # we note when an element is opened so that if two open_element()
        # calls are made successively we can end the currently open
        # tag and will later write a proper close tag. otherwise,
        # if a close_element() call is made directly after an open_element()
        # call we will close the tag with a />
        #
        if self.element_open == 1:
            self.file.write(">\n")

        self.element_open = 1

        # Helper function to write an element open tag with attributes
        self.file.write("%s<%s" % (TAB*self.indent_level, element))
        self.__write_attribs(attrs)

        self.indent_level += 1

    def close_element(self, element):
        self.indent_level -= 1
        assert self.indent_level >= 0

        # see open_element() for an explanation
        if self.element_open == 1:
            self.element_open = 0
            self.file.write("/>\n")
        else:
            self.file.write("%s</%s>\n" % (TAB*self.indent_level, element))

    def write_element(self, element, attrs = {}):
        """write an element that won't need a closing tag"""
        self.open_element(element, attrs)
        self.close_element(element)

    def __write_attribs(self, attrs):
        for name, value in attrs.items():
            self.file.write(' %s="%s"' % (self.encode(name), 
                                          self.encode(value)))

    def encode(self, str):
        """Return an XML-escaped and UTF-8 encoded copy of the string str."""

        esc = escape(str)

        if isinstance(esc, UnicodeType):
            return esc.encode("utf8")
        else:
            return unicode(escape(str),'latin1').encode("utf8")
1	jonathan	1171	# Copyright (c) 2003 by Intevation GmbH
2			# Authors:
3			# Jonathan Coles <[email protected]>
4			#
5			# This program is free software under the GPL (>=v2)
6			# Read the file COPYING coming with Thuban for details.
7
8			"""
9			Functions to save an XML file
10			"""
11
12			__version__ = "$Revision$"
13
14	jan	1886	import os
15	jonathan	1171	from types import UnicodeType
16
17			#
18			# one level of indention
19			#
20			TAB = " "
21
22			def escape(data):
23			"""Escape &, \", ', <, and > in a string of data.
24			"""
25	jan	1886	data = data.replace("&", "&")
26			data = data.replace("<", "<")
27			data = data.replace(">", ">")
28			data = data.replace('"', """)
29			data = data.replace("'", "'")
30	jonathan	1171	return data
31
32			class XMLWriter:
33			"""Abstract XMLWriter.
34
35			Should be overridden to provide specific object saving functionality.
36			"""
37
38			def __init__(self):
39			self.filename = None
40			pass
41
42			def write(self, file_or_filename):
43			"""Write the session to a file.
44
45			The argument may be either a file object or a filename. If it's
46			a filename, the file will be opened for writing. Files of
47			shapefiles will be stored as filenames relative to the directory
48			the file is stored in (as given by os.path.dirname(filename)) if
49			they have a common parent directory other than the root
50			directory.
51
52			If the argument is a file object (which is determined by the
53			presence of a write method) all filenames will be absolute
54			filenames.
55			"""
56
57			# keep track of how many levels of indentation to write
58			self.indent_level = 0
59			# track whether an element is currently open. see open_element().
60			self.element_open = 0
61
62			if hasattr(file_or_filename, "write"):
63			# it's a file object
64			self.file = file_or_filename
65			self.dir = ""
66			else:
67			self.filename = file_or_filename
68			self.dir = os.path.dirname(self.filename)
69			self.file = open(self.filename, 'w')
70
71			def close(self):
72			assert self.indent_level == 0
73			if self.filename is not None:
74			self.file.close()
75
76			def write_header(self, doctype, system):
77			"""Write the XML header"""
78			self.file.write('<?xml version="1.0" encoding="UTF-8"?>\n')
79			self.file.write('<!DOCTYPE %s SYSTEM "%s">\n' % (doctype, system))
80
81			def open_element(self, element, attrs = {}):
82
83			#
84			# we note when an element is opened so that if two open_element()
85			# calls are made successively we can end the currently open
86			# tag and will later write a proper close tag. otherwise,
87			# if a close_element() call is made directly after an open_element()
88			# call we will close the tag with a />
89			#
90			if self.element_open == 1:
91			self.file.write(">\n")
92
93			self.element_open = 1
94
95			# Helper function to write an element open tag with attributes
96			self.file.write("%s<%s" % (TAB*self.indent_level, element))
97			self.__write_attribs(attrs)
98
99			self.indent_level += 1
100
101			def close_element(self, element):
102			self.indent_level -= 1
103			assert self.indent_level >= 0
104
105			# see open_element() for an explanation
106			if self.element_open == 1:
107			self.element_open = 0
108			self.file.write("/>\n")
109			else:
110			self.file.write("%s</%s>\n" % (TAB*self.indent_level, element))
111
112			def write_element(self, element, attrs = {}):
113			"""write an element that won't need a closing tag"""
114			self.open_element(element, attrs)
115			self.close_element(element)
116
117			def __write_attribs(self, attrs):
118			for name, value in attrs.items():
119			self.file.write(' %s="%s"' % (self.encode(name),
120			self.encode(value)))
121
122			def encode(self, str):
123			"""Return an XML-escaped and UTF-8 encoded copy of the string str."""
124
125			esc = escape(str)
126
127			if isinstance(esc, UnicodeType):
128			return esc.encode("utf8")
129			else:
130			return unicode(escape(str),'latin1').encode("utf8")
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision