Fixed XMP unit tests.

2 files changed, 146 insertions, 209 deletions

diff --git a/src/pyexiv2/xmp.py b/src/pyexiv2/xmp.py
index ffed358..b5b7144 100644
--- a/src/pyexiv2/xmp.py
+++ b/src/pyexiv2/xmp.py
@@ -265,6 +265,8 @@ class XmpTag(object):
             raise NotImplementedError('XMP conversion for type [%s]' % type)
 
         elif type == 'MIMEType':
+            if value.count('/') != 1:
+                raise XmpValueError(value, type)
             try:
                 return tuple(value.split('/', 1))
             except ValueError:
@@ -321,9 +323,7 @@ class XmpTag(object):
                 raise XmpValueError(value, type)
 
         elif type == 'Date':
-            if isinstance(value, datetime.date):
-                return value.isoformat()
-            elif isinstance(value, datetime.datetime):
+            if isinstance(value, datetime.datetime):
                 if value.hour == 0 and value.minute == 0 and \
                     value.second == 0 and value.microsecond == 0 and \
                     (value.tzinfo is None or value.tzinfo == FixedOffset()):
@@ -337,6 +337,8 @@ class XmpTag(object):
                     r += str(int(value.microsecond) / 1E6)[2:]
                     r += value.strftime('%Z')
                     return r
+            elif isinstance(value, datetime.date):
+                return value.isoformat()
             else:
                 raise XmpValueError(value, type)
 
@@ -347,11 +349,8 @@ class XmpTag(object):
                 raise XmpValueError(value, type)
 
         elif type == 'MIMEType':
-            if isinstance(value, tuple):
-                try:
-                    return '/'.join(value)
-                except KeyError:
-                    raise XmpValueError(value, type)
+            if isinstance(value, tuple) and len(value) == 2:
+                return '/'.join(value)
             else:
                 raise XmpValueError(value, type)
 
diff --git a/test/xmp.py b/test/xmp.py
index a61e375..cd0fabe 100644
--- a/test/xmp.py
+++ b/test/xmp.py
@@ -39,332 +39,270 @@ class ImageMetadataMock(object):
     def _set_xmp_tag_value(self, key, value):
         self.tags[key] = value
 
-    def _delete_xmp_tag(self, key):
-        try:
-            del self.tags[key]
-        except KeyError:
-            pass
-
 
 class TestXmpTag(unittest.TestCase):
 
     def test_convert_to_python_bag(self):
-        xtype = 'bag Text'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('', xtype), [])
-        self.assertEqual(XmpTag._convert_to_python('One value only', xtype), [u'One value only'])
-        self.assertEqual(XmpTag._convert_to_python('Some, text, keyword, this is a test', xtype),
-                         [u'Some', u'text', u'keyword', u'this is a test'])
+        tag = XmpTag('Xmp.dc.subject')
+        self.assertEqual(tag.type, 'bag Text')
+        self.assertEqual(tag._convert_to_python('', 'Text'), u'')
+        self.assertEqual(tag._convert_to_python('One value only', 'Text'),
+                         u'One value only')
 
     def test_convert_to_string_bag(self):
-        xtype = 'bag Text'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string([], xtype), '')
-        self.assertEqual(XmpTag._convert_to_string(['One value only'], xtype), 'One value only')
-        self.assertEqual(XmpTag._convert_to_string([u'One value only'], xtype), 'One value only')
-        self.assertEqual(XmpTag._convert_to_string([u'Some', u'text', u'keyword', u'this is a test'], xtype),
-                         'Some, text, keyword, this is a test')
-        self.assertEqual(XmpTag._convert_to_string(['Some   ', '  text    '], xtype),
-                         'Some   ,   text    ')
+        tag = XmpTag('Xmp.dc.subject')
+        self.assertEqual(tag.type, 'bag Text')
+        self.assertEqual(tag._convert_to_string(u'', 'Text'), '')
+        self.assertEqual(tag._convert_to_string('One value only', 'Text'), 'One value only')
+        self.assertEqual(tag._convert_to_string(u'One value only', 'Text'), 'One value only')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, [1, 2, 3], xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, [1, 2, 3], 'Text')
 
     def test_convert_to_python_boolean(self):
-        xtype = 'Boolean'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('True', xtype), True)
-        self.assertEqual(XmpTag._convert_to_python('False', xtype), False)
+        tag = XmpTag('Xmp.xmpRights.Marked')
+        self.assertEqual(tag.type, 'Boolean')
+        self.assertEqual(tag._convert_to_python('True', 'Boolean'), True)
+        self.assertEqual(tag._convert_to_python('False', 'Boolean'), False)
         # Invalid values: not converted
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, 'invalid', 'Boolean')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, None, 'Boolean')
 
     def test_convert_to_string_boolean(self):
-        xtype = 'Boolean'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string(True, xtype), 'True')
-        self.assertEqual(XmpTag._convert_to_string(False, xtype), 'False')
+        tag = XmpTag('Xmp.xmpRights.Marked')
+        self.assertEqual(tag.type, 'Boolean')
+        self.assertEqual(tag._convert_to_string(True, 'Boolean'), 'True')
+        self.assertEqual(tag._convert_to_string(False, 'Boolean'), 'False')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, 'invalid', 'Boolean')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, None, 'Boolean')
 
     def test_convert_to_python_date(self):
-        xtype = 'Date'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('1999', xtype),
+        tag = XmpTag('Xmp.xmp.CreateDate')
+        self.assertEqual(tag.type, 'Date')
+        self.assertEqual(tag._convert_to_python('1999', 'Date'),
                          datetime.date(1999, 1, 1))
-        self.assertEqual(XmpTag._convert_to_python('1999-10', xtype),
+        self.assertEqual(tag._convert_to_python('1999-10', 'Date'),
                          datetime.date(1999, 10, 1))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13', xtype),
+        self.assertEqual(tag._convert_to_python('1999-10-13', 'Date'),
                          datetime.date(1999, 10, 13))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03Z', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03Z', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset()),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03+06:00', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03+06:00', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset('+', 6, 0)),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03-06:00', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03-06:00', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset('-', 6, 0)),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03:54Z', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03:54Z', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, 54, tzinfo=FixedOffset()),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03:54+06:00', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03:54+06:00', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, 54, tzinfo=FixedOffset('+', 6, 0)),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03:54-06:00', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03:54-06:00', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, 54, tzinfo=FixedOffset('-', 6, 0)),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03:54.721Z', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03:54.721Z', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, 54, 721000, tzinfo=FixedOffset()),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03:54.721+06:00', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03:54.721+06:00', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, 54, 721000, tzinfo=FixedOffset('+', 6, 0)),
                          datetime.timedelta(0))
-        self.assertEqual(XmpTag._convert_to_python('1999-10-13T05:03:54.721-06:00', xtype) - \
+        self.assertEqual(tag._convert_to_python('1999-10-13T05:03:54.721-06:00', 'Date') - \
                          datetime.datetime(1999, 10, 13, 5, 3, 54, 721000, tzinfo=FixedOffset('-', 6, 0)),
                          datetime.timedelta(0))
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '11/10/1983', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '-1000', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '2009-13', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '2009-10-32', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '2009-10-30T25:12Z', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '2009-10-30T23:67Z', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '2009-01-22T21', xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, 'invalid', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '11/10/1983', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '-1000', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '2009-13', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '2009-10-32', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '2009-10-30T25:12Z', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '2009-10-30T23:67Z', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '2009-01-22T21', 'Date')
 
     def test_convert_to_string_date(self):
-        xtype = 'Date'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string(datetime.date(2009, 2, 4), xtype),
+        tag = XmpTag('Xmp.xmp.CreateDate')
+        self.assertEqual(tag.type, 'Date')
+        self.assertEqual(tag._convert_to_string(datetime.date(2009, 2, 4), 'Date'),
                          '2009-02-04')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13), 'Date'),
                          '1999-10-13')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset()), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset()), 'Date'),
                          '1999-10-13T05:03Z')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset('+', 5, 30)), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset('+', 5, 30)), 'Date'),
                          '1999-10-13T05:03+05:30')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset('-', 11, 30)), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, tzinfo=FixedOffset('-', 11, 30)), 'Date'),
                          '1999-10-13T05:03-11:30')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, tzinfo=FixedOffset()), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, tzinfo=FixedOffset()), 'Date'),
                          '1999-10-13T05:03:27Z')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, tzinfo=FixedOffset('+', 5, 30)), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, tzinfo=FixedOffset('+', 5, 30)), 'Date'),
                          '1999-10-13T05:03:27+05:30')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, tzinfo=FixedOffset('-', 11, 30)), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, tzinfo=FixedOffset('-', 11, 30)), 'Date'),
                          '1999-10-13T05:03:27-11:30')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, 124300, tzinfo=FixedOffset()), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, 124300, tzinfo=FixedOffset()), 'Date'),
                          '1999-10-13T05:03:27.1243Z')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, 124300, tzinfo=FixedOffset('+', 5, 30)), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, 124300, tzinfo=FixedOffset('+', 5, 30)), 'Date'),
                          '1999-10-13T05:03:27.1243+05:30')
-        self.assertEqual(XmpTag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, 124300, tzinfo=FixedOffset('-', 11, 30)), xtype),
+        self.assertEqual(tag._convert_to_string(datetime.datetime(1999, 10, 13, 5, 3, 27, 124300, tzinfo=FixedOffset('-', 11, 30)), 'Date'),
                          '1999-10-13T05:03:27.1243-11:30')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, 'invalid', 'Date')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, None, 'Date')
 
     def test_convert_to_python_integer(self):
-        xtype = 'Integer'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('23', xtype), 23)
-        self.assertEqual(XmpTag._convert_to_python('+5628', xtype), 5628)
-        self.assertEqual(XmpTag._convert_to_python('-4', xtype), -4)
+        tag = XmpTag('Xmp.xmpMM.SaveID')
+        self.assertEqual(tag.type, 'Integer')
+        self.assertEqual(tag._convert_to_python('23', 'Integer'), 23)
+        self.assertEqual(tag._convert_to_python('+5628', 'Integer'), 5628)
+        self.assertEqual(tag._convert_to_python('-4', 'Integer'), -4)
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'abc', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '5,64', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '47.0001', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, '1E3', xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, 'abc', 'Integer')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '5,64', 'Integer')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '47.0001', 'Integer')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, '1E3', 'Integer')
 
     def test_convert_to_string_integer(self):
-        xtype = 'Integer'
-        # Valid values
-        self.assertEqual(XmpTag._convert_to_string(123, xtype), '123')
-        self.assertEqual(XmpTag._convert_to_string(-57, xtype), '-57')
-        # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 3.14, xtype)
-
-    def test_convert_to_python_langalt(self):
-        xtype = 'Lang Alt'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('lang="x-default" some text', xtype),
-                         {'x-default': u'some text'})
-        self.assertEqual(XmpTag._convert_to_python('lang="x-default" some text, lang="fr-FR" du texte', xtype),
-                         {'x-default': u'some text', 'fr-FR': u'du texte'})
-        self.assertEqual(XmpTag._convert_to_python('lang="x-default" some text   ,    lang="fr-FR"   du texte  ', xtype),
-                         {'x-default': u'some text   ', 'fr-FR': u'  du texte  '})
-        self.assertEqual(XmpTag._convert_to_python('lang="x-default" some text, lang="fr-FR" du texte, lang="es-ES" un texto', xtype),
-                         {'x-default': u'some text', 'fr-FR': u'du texte', 'es-ES': u'un texto'})
+        tag = XmpTag('Xmp.xmpMM.SaveID')
+        self.assertEqual(tag.type, 'Integer')
+        self.assertEqual(tag._convert_to_string(123, 'Integer'), '123')
+        self.assertEqual(tag._convert_to_string(-57, 'Integer'), '-57')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'lang="malformed', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'xlang="x-default" some text', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'lang="x-default" some text, xlang="fr-FR" du texte', xtype)
-
-    def test_convert_to_string_langalt(self):
-        xtype = 'Lang Alt'
-        # Valid values
-        self.assertEqual(XmpTag._convert_to_string({'x-default': 'some text'}, xtype),
-                         'lang="x-default" some text')
-        self.assertEqual(XmpTag._convert_to_string({'x-default': u'some text'}, xtype),
-                         'lang="x-default" some text')
-        self.assertEqual(XmpTag._convert_to_string({'x-default': 'some text', 'fr-FR': 'du texte'}, xtype),
-                         'lang="x-default" some text, lang="fr-FR" du texte')
-        self.assertEqual(XmpTag._convert_to_string({'x-default': u'some text', 'fr-FR': 'du texte'}, xtype),
-                         'lang="x-default" some text, lang="fr-FR" du texte')
-        self.assertEqual(XmpTag._convert_to_string({'x-default': u'some text', 'fr-FR': 'du texte', 'es-ES': 'un texto'}, xtype),
-                         'lang="x-default" some text, lang="es-ES" un texto, lang="fr-FR" du texte')
-        # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, {}, xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, {'x-default': 25}, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, 'invalid', 'Integer')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, 3.14, 'Integer')
 
     def test_convert_to_python_mimetype(self):
-        xtype = 'MIMEType'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('image/jpeg', xtype),
-                         {'type': 'image', 'subtype': 'jpeg'})
-        self.assertEqual(XmpTag._convert_to_python('video/ogg', xtype),
-                         {'type': 'video', 'subtype': 'ogg'})
+        tag = XmpTag('Xmp.dc.format')
+        self.assertEqual(tag.type, 'MIMEType')
+        self.assertEqual(tag._convert_to_python('image/jpeg', 'MIMEType'),
+                         ('image', 'jpeg'))
+        self.assertEqual(tag._convert_to_python('video/ogg', 'MIMEType'),
+                         ('video', 'ogg'))
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, 'image-jpeg', xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, 'invalid', 'MIMEType')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, 'image-jpeg', 'MIMEType')
 
     def test_convert_to_string_mimetype(self):
-        xtype = 'MIMEType'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string({'type': 'image', 'subtype': 'jpeg'}, xtype), 'image/jpeg')
-        self.assertEqual(XmpTag._convert_to_string({'type': 'video', 'subtype': 'ogg'}, xtype), 'video/ogg')
+        tag = XmpTag('Xmp.dc.format')
+        self.assertEqual(tag.type, 'MIMEType')
+        self.assertEqual(tag._convert_to_string(('image', 'jpeg'), 'MIMEType'), 'image/jpeg')
+        self.assertEqual(tag._convert_to_string(('video', 'ogg'), 'MIMEType'), 'video/ogg')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, 'invalid', xtype)
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, {'type': 'image'}, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, 'invalid', 'MIMEType')
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, ('image',), 'MIMEType')
 
     def test_convert_to_python_propername(self):
-        xtype = 'ProperName'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('Gérard', xtype), u'Gérard')
-        self.assertEqual(XmpTag._convert_to_python('Python Software Foundation', xtype), u'Python Software Foundation')
+        tag = XmpTag('Xmp.photoshop.CaptionWriter')
+        self.assertEqual(tag.type, 'ProperName')
+        self.assertEqual(tag._convert_to_python('Gérard', 'ProperName'), u'Gérard')
+        self.assertEqual(tag._convert_to_python('Python Software Foundation', 'ProperName'), u'Python Software Foundation')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, None, 'ProperName')
 
     def test_convert_to_string_propername(self):
-        xtype = 'ProperName'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string('Gérard', xtype), 'Gérard')
-        self.assertEqual(XmpTag._convert_to_string(u'Gérard', xtype), 'Gérard')
-        self.assertEqual(XmpTag._convert_to_string(u'Python Software Foundation', xtype), 'Python Software Foundation')
+        tag = XmpTag('Xmp.photoshop.CaptionWriter')
+        self.assertEqual(tag.type, 'ProperName')
+        self.assertEqual(tag._convert_to_string('Gérard', 'ProperName'), 'Gérard')
+        self.assertEqual(tag._convert_to_string(u'Gérard', 'ProperName'), 'Gérard')
+        self.assertEqual(tag._convert_to_string(u'Python Software Foundation', 'ProperName'), 'Python Software Foundation')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, None, 'ProperName')
 
     def test_convert_to_python_text(self):
-        xtype = 'Text'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('Some text.', xtype), u'Some text.')
-        self.assertEqual(XmpTag._convert_to_python('Some text with exotic chàräctérʐ.', xtype),
+        tag = XmpTag('Xmp.dc.source')
+        self.assertEqual(tag.type, 'Text')
+        self.assertEqual(tag._convert_to_python('Some text.', 'Text'), u'Some text.')
+        self.assertEqual(tag._convert_to_python('Some text with exotic chàräctérʐ.', 'Text'),
                          u'Some text with exotic chàräctérʐ.')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_python, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_python, None, 'Text')
 
     def test_convert_to_string_text(self):
-        xtype = 'Text'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string(u'Some text', xtype), 'Some text')
-        self.assertEqual(XmpTag._convert_to_string(u'Some text with exotic chàräctérʐ.', xtype),
+        tag = XmpTag('Xmp.dc.source')
+        self.assertEqual(tag.type, 'Text')
+        self.assertEqual(tag._convert_to_string(u'Some text', 'Text'), 'Some text')
+        self.assertEqual(tag._convert_to_string(u'Some text with exotic chàräctérʐ.', 'Text'),
                          'Some text with exotic chàräctérʐ.')
-        self.assertEqual(XmpTag._convert_to_string('Some text with exotic chàräctérʐ.', xtype),
+        self.assertEqual(tag._convert_to_string('Some text with exotic chàräctérʐ.', 'Text'),
                          'Some text with exotic chàräctérʐ.')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, None, 'Text')
 
     def test_convert_to_python_uri(self):
-        xtype = 'URI'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('http://example.com', xtype), 'http://example.com')
-        self.assertEqual(XmpTag._convert_to_python('https://example.com', xtype), 'https://example.com')
-        self.assertEqual(XmpTag._convert_to_python('http://localhost:8000/resource', xtype),
+        tag = XmpTag('Xmp.xmpMM.DocumentID')
+        self.assertEqual(tag.type, 'URI')
+        self.assertEqual(tag._convert_to_python('http://example.com', 'URI'), 'http://example.com')
+        self.assertEqual(tag._convert_to_python('https://example.com', 'URI'), 'https://example.com')
+        self.assertEqual(tag._convert_to_python('http://localhost:8000/resource', 'URI'),
                          'http://localhost:8000/resource')
-        self.assertEqual(XmpTag._convert_to_python('uuid:9A3B7F52214211DAB6308A7391270C13', xtype),
+        self.assertEqual(tag._convert_to_python('uuid:9A3B7F52214211DAB6308A7391270C13', 'URI'),
                          'uuid:9A3B7F52214211DAB6308A7391270C13')
 
     def test_convert_to_string_uri(self):
-        xtype = 'URI'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string('http://example.com', xtype), 'http://example.com')
-        self.assertEqual(XmpTag._convert_to_string(u'http://example.com', xtype), 'http://example.com')
-        self.assertEqual(XmpTag._convert_to_string('https://example.com', xtype), 'https://example.com')
-        self.assertEqual(XmpTag._convert_to_string('http://localhost:8000/resource', xtype),
+        tag = XmpTag('Xmp.xmpMM.DocumentID')
+        self.assertEqual(tag.type, 'URI')
+        self.assertEqual(tag._convert_to_string('http://example.com', 'URI'), 'http://example.com')
+        self.assertEqual(tag._convert_to_string(u'http://example.com', 'URI'), 'http://example.com')
+        self.assertEqual(tag._convert_to_string('https://example.com', 'URI'), 'https://example.com')
+        self.assertEqual(tag._convert_to_string('http://localhost:8000/resource', 'URI'),
                          'http://localhost:8000/resource')
-        self.assertEqual(XmpTag._convert_to_string('uuid:9A3B7F52214211DAB6308A7391270C13', xtype),
+        self.assertEqual(tag._convert_to_string('uuid:9A3B7F52214211DAB6308A7391270C13', 'URI'),
                          'uuid:9A3B7F52214211DAB6308A7391270C13')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, None, 'URI')
 
     def test_convert_to_python_url(self):
-        xtype = 'URL'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_python('http://example.com', xtype), 'http://example.com')
-        self.assertEqual(XmpTag._convert_to_python('https://example.com', xtype), 'https://example.com')
-        self.assertEqual(XmpTag._convert_to_python('http://localhost:8000/resource', xtype),
+        tag = XmpTag('Xmp.xmp.BaseURL')
+        self.assertEqual(tag.type, 'URL')
+        self.assertEqual(tag._convert_to_python('http://example.com', 'URL'), 'http://example.com')
+        self.assertEqual(tag._convert_to_python('https://example.com', 'URL'), 'https://example.com')
+        self.assertEqual(tag._convert_to_python('http://localhost:8000/resource', 'URL'),
                          'http://localhost:8000/resource')
 
     def test_convert_to_string_url(self):
-        xtype = 'URL'
         # Valid values
-        self.assertEqual(XmpTag._convert_to_string('http://example.com', xtype), 'http://example.com')
-        self.assertEqual(XmpTag._convert_to_string(u'http://example.com', xtype), 'http://example.com')
-        self.assertEqual(XmpTag._convert_to_string('https://example.com', xtype), 'https://example.com')
-        self.assertEqual(XmpTag._convert_to_string('http://localhost:8000/resource', xtype),
+        tag = XmpTag('Xmp.xmp.BaseURL')
+        self.assertEqual(tag.type, 'URL')
+        self.assertEqual(tag._convert_to_string('http://example.com', 'URL'), 'http://example.com')
+        self.assertEqual(tag._convert_to_string(u'http://example.com', 'URL'), 'http://example.com')
+        self.assertEqual(tag._convert_to_string('https://example.com', 'URL'), 'https://example.com')
+        self.assertEqual(tag._convert_to_string('http://localhost:8000/resource', 'URL'),
                          'http://localhost:8000/resource')
         # Invalid values
-        self.failUnlessRaises(XmpValueError, XmpTag._convert_to_string, None, xtype)
+        self.failUnlessRaises(XmpValueError, tag._convert_to_string, None, 'URL')
 
     # TODO: other types
 
 
     def test_set_value_no_metadata(self):
-        tag = XmpTag('Xmp.xmp.ModifyDate', 'ModifyDate', 'Modify Date',
-                     'The date and time the resource was last modified. Note:' \
-                     ' The value of this property is not necessarily the same' \
-                     "as the file's system modification date because it is " \
-                     'set before the file is saved.', 'Date',
-                     '2005-09-07T15:09:51-07:00')
+        tag = XmpTag('Xmp.xmp.ModifyDate', datetime.datetime(2005, 9, 7, 15, 9, 51, tzinfo=FixedOffset('-', 7, 0)))
         old_value = tag.value
         tag.value = datetime.datetime(2009, 4, 22, 8, 30, 27, tzinfo=FixedOffset())
         self.failIfEqual(tag.value, old_value)
 
     def test_set_value_with_metadata(self):
-        tag = XmpTag('Xmp.xmp.ModifyDate', 'ModifyDate', 'Modify Date',
-                     'The date and time the resource was last modified. Note:' \
-                     ' The value of this property is not necessarily the same' \
-                     "as the file's system modification date because it is " \
-                     'set before the file is saved.', 'Date',
-                     '2005-09-07T15:09:51-07:00')
+        tag = XmpTag('Xmp.xmp.ModifyDate', datetime.datetime(2005, 9, 7, 15, 9, 51, tzinfo=FixedOffset('-', 7, 0)))
         tag.metadata = ImageMetadataMock()
         old_value = tag.value
         tag.value = datetime.datetime(2009, 4, 22, 8, 30, 27, tzinfo=FixedOffset())
         self.failIfEqual(tag.value, old_value)
         self.assertEqual(tag.metadata.tags[tag.key], '2009-04-22T08:30:27Z')
 
-    def test_del_value_no_metadata(self):
-        tag = XmpTag('Xmp.xmp.ModifyDate', 'ModifyDate', 'Modify Date',
-                     'The date and time the resource was last modified. Note:' \
-                     ' The value of this property is not necessarily the same' \
-                     "as the file's system modification date because it is " \
-                     'set before the file is saved.', 'Date',
-                     '2005-09-07T15:09:51-07:00')
-        del tag.value
-        self.failIf(hasattr(tag, 'value'))
-
-    def test_del_value_with_metadata(self):
-        tag = XmpTag('Xmp.xmp.ModifyDate', 'ModifyDate', 'Modify Date',
-                     'The date and time the resource was last modified. Note:' \
-                     ' The value of this property is not necessarily the same' \
-                     "as the file's system modification date because it is " \
-                     'set before the file is saved.', 'Date',
-                     '2005-09-07T15:09:51-07:00')
-        tag.metadata = ImageMetadataMock()
-        tag.metadata._set_xmp_tag_value(tag.key, tag.to_string())
-        self.assertEqual(tag.metadata.tags, {tag.key: '2005-09-07T15:09:51-07:00'})
-        del tag.value
-        self.failIf(hasattr(tag, 'value'))
-        self.failIf(tag.metadata.tags.has_key(tag.key))