Thuban/Model/xmlwriter.py

# Copyright (c) 2003, 2005 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

from Thuban import unicode_from_internal

#
# 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, s):
        """Return an XML-escaped and UTF-8 encoded copy of the string s.

        The parameter must be a string in Thuban's internal string
        representation or a unicode object.
        """
        if not isinstance(s, unicode):
            s = unicode_from_internal(s)
        return escape(s).encode("utf8")
1	bh	2642	# Copyright (c) 2003, 2005 by Intevation GmbH
2	jonathan	1171	# 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	bh	2642	from Thuban import unicode_from_internal
18
19	jonathan	1171	#
20			# one level of indention
21			#
22			TAB = " "
23
24			def escape(data):
25			"""Escape &, \", ', <, and > in a string of data.
26			"""
27	jan	1886	data = data.replace("&", "&")
28			data = data.replace("<", "<")
29			data = data.replace(">", ">")
30			data = data.replace('"', """)
31			data = data.replace("'", "'")
32	jonathan	1171	return data
33
34			class XMLWriter:
35			"""Abstract XMLWriter.
36
37			Should be overridden to provide specific object saving functionality.
38			"""
39
40			def __init__(self):
41			self.filename = None
42			pass
43
44			def write(self, file_or_filename):
45			"""Write the session to a file.
46
47			The argument may be either a file object or a filename. If it's
48			a filename, the file will be opened for writing. Files of
49			shapefiles will be stored as filenames relative to the directory
50			the file is stored in (as given by os.path.dirname(filename)) if
51			they have a common parent directory other than the root
52			directory.
53
54			If the argument is a file object (which is determined by the
55			presence of a write method) all filenames will be absolute
56			filenames.
57			"""
58
59			# keep track of how many levels of indentation to write
60			self.indent_level = 0
61			# track whether an element is currently open. see open_element().
62			self.element_open = 0
63
64			if hasattr(file_or_filename, "write"):
65			# it's a file object
66			self.file = file_or_filename
67			self.dir = ""
68			else:
69			self.filename = file_or_filename
70			self.dir = os.path.dirname(self.filename)
71			self.file = open(self.filename, 'w')
72
73			def close(self):
74			assert self.indent_level == 0
75			if self.filename is not None:
76			self.file.close()
77
78			def write_header(self, doctype, system):
79			"""Write the XML header"""
80			self.file.write('<?xml version="1.0" encoding="UTF-8"?>\n')
81			self.file.write('<!DOCTYPE %s SYSTEM "%s">\n' % (doctype, system))
82
83			def open_element(self, element, attrs = {}):
84
85			#
86			# we note when an element is opened so that if two open_element()
87			# calls are made successively we can end the currently open
88			# tag and will later write a proper close tag. otherwise,
89			# if a close_element() call is made directly after an open_element()
90			# call we will close the tag with a />
91			#
92			if self.element_open == 1:
93			self.file.write(">\n")
94
95			self.element_open = 1
96
97			# Helper function to write an element open tag with attributes
98			self.file.write("%s<%s" % (TAB*self.indent_level, element))
99			self.__write_attribs(attrs)
100
101			self.indent_level += 1
102
103			def close_element(self, element):
104			self.indent_level -= 1
105			assert self.indent_level >= 0
106
107			# see open_element() for an explanation
108			if self.element_open == 1:
109			self.element_open = 0
110			self.file.write("/>\n")
111			else:
112			self.file.write("%s</%s>\n" % (TAB*self.indent_level, element))
113
114			def write_element(self, element, attrs = {}):
115			"""write an element that won't need a closing tag"""
116			self.open_element(element, attrs)
117			self.close_element(element)
118
119			def __write_attribs(self, attrs):
120			for name, value in attrs.items():
121			self.file.write(' %s="%s"' % (self.encode(name),
122			self.encode(value)))
123
124	bh	2642	def encode(self, s):
125			"""Return an XML-escaped and UTF-8 encoded copy of the string s.
126	jonathan	1171
127	bh	2642	The parameter must be a string in Thuban's internal string
128			representation or a unicode object.
129			"""
130			if not isinstance(s, unicode):
131			s = unicode_from_internal(s)
132			return escape(s).encode("utf8")
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision