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1"""Converts an IRI to a URI."""
2
3__author__ = "Joe Gregorio (joe@bitworking.org)"
4__copyright__ = "Copyright 2006, Joe Gregorio"
5__contributors__ = []
6__version__ = "1.0.0"
7__license__ = "MIT"
8
9import urlparse
10
11# Convert an IRI to a URI following the rules in RFC 3987
12#
13# The characters we need to enocde and escape are defined in the spec:
14#
15# iprivate =  %xE000-F8FF / %xF0000-FFFFD / %x100000-10FFFD
16# ucschar = %xA0-D7FF / %xF900-FDCF / %xFDF0-FFEF
17#         / %x10000-1FFFD / %x20000-2FFFD / %x30000-3FFFD
18#         / %x40000-4FFFD / %x50000-5FFFD / %x60000-6FFFD
19#         / %x70000-7FFFD / %x80000-8FFFD / %x90000-9FFFD
20#         / %xA0000-AFFFD / %xB0000-BFFFD / %xC0000-CFFFD
21#         / %xD0000-DFFFD / %xE1000-EFFFD
22
23escape_range = [
24    (0xA0, 0xD7FF),
25    (0xE000, 0xF8FF),
26    (0xF900, 0xFDCF),
27    (0xFDF0, 0xFFEF),
28    (0x10000, 0x1FFFD),
29    (0x20000, 0x2FFFD),
30    (0x30000, 0x3FFFD),
31    (0x40000, 0x4FFFD),
32    (0x50000, 0x5FFFD),
33    (0x60000, 0x6FFFD),
34    (0x70000, 0x7FFFD),
35    (0x80000, 0x8FFFD),
36    (0x90000, 0x9FFFD),
37    (0xA0000, 0xAFFFD),
38    (0xB0000, 0xBFFFD),
39    (0xC0000, 0xCFFFD),
40    (0xD0000, 0xDFFFD),
41    (0xE1000, 0xEFFFD),
42    (0xF0000, 0xFFFFD),
43    (0x100000, 0x10FFFD),
44]
45
46
47def encode(c):
48    retval = c
49    i = ord(c)
50    for low, high in escape_range:
51        if i < low:
52            break
53        if i >= low and i <= high:
54            retval = "".join(["%%%2X" % ord(o) for o in c.encode("utf-8")])
55            break
56    return retval
57
58
59def iri2uri(uri):
60    """Convert an IRI to a URI. Note that IRIs must be
61    passed in a unicode strings. That is, do not utf-8 encode
62    the IRI before passing it into the function."""
63    if isinstance(uri, unicode):
64        (scheme, authority, path, query, fragment) = urlparse.urlsplit(uri)
65        authority = authority.encode("idna")
66        # For each character in 'ucschar' or 'iprivate'
67        #  1. encode as utf-8
68        #  2. then %-encode each octet of that utf-8
69        uri = urlparse.urlunsplit((scheme, authority, path, query, fragment))
70        uri = "".join([encode(c) for c in uri])
71    return uri
72
73
74if __name__ == "__main__":
75    import unittest
76
77    class Test(unittest.TestCase):
78        def test_uris(self):
79            """Test that URIs are invariant under the transformation."""
80            invariant = [
81                u"ftp://ftp.is.co.za/rfc/rfc1808.txt",
82                u"http://www.ietf.org/rfc/rfc2396.txt",
83                u"ldap://[2001:db8::7]/c=GB?objectClass?one",
84                u"mailto:John.Doe@example.com",
85                u"news:comp.infosystems.www.servers.unix",
86                u"tel:+1-816-555-1212",
87                u"telnet://192.0.2.16:80/",
88                u"urn:oasis:names:specification:docbook:dtd:xml:4.1.2",
89            ]
90            for uri in invariant:
91                self.assertEqual(uri, iri2uri(uri))
92
93        def test_iri(self):
94            """Test that the right type of escaping is done for each part of the URI."""
95            self.assertEqual(
96                "http://xn--o3h.com/%E2%98%84",
97                iri2uri(u"http://\N{COMET}.com/\N{COMET}"),
98            )
99            self.assertEqual(
100                "http://bitworking.org/?fred=%E2%98%84",
101                iri2uri(u"http://bitworking.org/?fred=\N{COMET}"),
102            )
103            self.assertEqual(
104                "http://bitworking.org/#%E2%98%84",
105                iri2uri(u"http://bitworking.org/#\N{COMET}"),
106            )
107            self.assertEqual("#%E2%98%84", iri2uri(u"#\N{COMET}"))
108            self.assertEqual(
109                "/fred?bar=%E2%98%9A#%E2%98%84",
110                iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}"),
111            )
112            self.assertEqual(
113                "/fred?bar=%E2%98%9A#%E2%98%84",
114                iri2uri(iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}")),
115            )
116            self.assertNotEqual(
117                "/fred?bar=%E2%98%9A#%E2%98%84",
118                iri2uri(
119                    u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}".encode("utf-8")
120                ),
121            )
122
123    unittest.main()
124