1"""
2iri2uri
3
4Converts an IRI to a URI.
5
6"""
7__author__ = "Joe Gregorio (joe@bitworking.org)"
8__copyright__ = "Copyright 2006, Joe Gregorio"
9__contributors__ = []
10__version__ = "1.0.0"
11__license__ = "MIT"
12__history__ = """
13"""
14
15import urlparse
16
17
18# Convert an IRI to a URI following the rules in RFC 3987
19#
20# The characters we need to enocde and escape are defined in the spec:
21#
22# iprivate =  %xE000-F8FF / %xF0000-FFFFD / %x100000-10FFFD
23# ucschar = %xA0-D7FF / %xF900-FDCF / %xFDF0-FFEF
24#         / %x10000-1FFFD / %x20000-2FFFD / %x30000-3FFFD
25#         / %x40000-4FFFD / %x50000-5FFFD / %x60000-6FFFD
26#         / %x70000-7FFFD / %x80000-8FFFD / %x90000-9FFFD
27#         / %xA0000-AFFFD / %xB0000-BFFFD / %xC0000-CFFFD
28#         / %xD0000-DFFFD / %xE1000-EFFFD
29
30escape_range = [
31   (0xA0, 0xD7FF ),
32   (0xE000, 0xF8FF ),
33   (0xF900, 0xFDCF ),
34   (0xFDF0, 0xFFEF),
35   (0x10000, 0x1FFFD ),
36   (0x20000, 0x2FFFD ),
37   (0x30000, 0x3FFFD),
38   (0x40000, 0x4FFFD ),
39   (0x50000, 0x5FFFD ),
40   (0x60000, 0x6FFFD),
41   (0x70000, 0x7FFFD ),
42   (0x80000, 0x8FFFD ),
43   (0x90000, 0x9FFFD),
44   (0xA0000, 0xAFFFD ),
45   (0xB0000, 0xBFFFD ),
46   (0xC0000, 0xCFFFD),
47   (0xD0000, 0xDFFFD ),
48   (0xE1000, 0xEFFFD),
49   (0xF0000, 0xFFFFD ),
50   (0x100000, 0x10FFFD)
51]
52
53def encode(c):
54    retval = c
55    i = ord(c)
56    for low, high in escape_range:
57        if i < low:
58            break
59        if i >= low and i <= high:
60            retval = "".join(["%%%2X" % ord(o) for o in c.encode('utf-8')])
61            break
62    return retval
63
64
65def iri2uri(uri):
66    """Convert an IRI to a URI. Note that IRIs must be
67    passed in a unicode strings. That is, do not utf-8 encode
68    the IRI before passing it into the function."""
69    if isinstance(uri ,unicode):
70        (scheme, authority, path, query, fragment) = urlparse.urlsplit(uri)
71        authority = authority.encode('idna')
72        # For each character in 'ucschar' or 'iprivate'
73        #  1. encode as utf-8
74        #  2. then %-encode each octet of that utf-8
75        uri = urlparse.urlunsplit((scheme, authority, path, query, fragment))
76        uri = "".join([encode(c) for c in uri])
77    return uri
78
79if __name__ == "__main__":
80    import unittest
81
82    class Test(unittest.TestCase):
83
84        def test_uris(self):
85            """Test that URIs are invariant under the transformation."""
86            invariant = [
87                u"ftp://ftp.is.co.za/rfc/rfc1808.txt",
88                u"http://www.ietf.org/rfc/rfc2396.txt",
89                u"ldap://[2001:db8::7]/c=GB?objectClass?one",
90                u"mailto:John.Doe@example.com",
91                u"news:comp.infosystems.www.servers.unix",
92                u"tel:+1-816-555-1212",
93                u"telnet://192.0.2.16:80/",
94                u"urn:oasis:names:specification:docbook:dtd:xml:4.1.2" ]
95            for uri in invariant:
96                self.assertEqual(uri, iri2uri(uri))
97
98        def test_iri(self):
99            """ Test that the right type of escaping is done for each part of the URI."""
100            self.assertEqual("http://xn--o3h.com/%E2%98%84", iri2uri(u"http://\N{COMET}.com/\N{COMET}"))
101            self.assertEqual("http://bitworking.org/?fred=%E2%98%84", iri2uri(u"http://bitworking.org/?fred=\N{COMET}"))
102            self.assertEqual("http://bitworking.org/#%E2%98%84", iri2uri(u"http://bitworking.org/#\N{COMET}"))
103            self.assertEqual("#%E2%98%84", iri2uri(u"#\N{COMET}"))
104            self.assertEqual("/fred?bar=%E2%98%9A#%E2%98%84", iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}"))
105            self.assertEqual("/fred?bar=%E2%98%9A#%E2%98%84", iri2uri(iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}")))
106            self.assertNotEqual("/fred?bar=%E2%98%9A#%E2%98%84", iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}".encode('utf-8')))
107
108    unittest.main()
109
110
111