1 files changed, 91 insertions, 0 deletions
diff --git a/lib/testtools/content.py b/lib/testtools/content.py
new file mode 100644
index 0000000000..353e3f0f46
--- /dev/null
+++ b/lib/testtools/content.py
@@ -0,0 +1,91 @@
+# Copyright (c) 2009 Jonathan M. Lange. See LICENSE for details.
+
+"""Content - a MIME-like Content object."""
+
+import codecs
+from unittest import TestResult
+
+from testtools.content_type import ContentType
+from testtools.utils import _b
+
+
+class Content(object):
+    """A MIME-like Content object.
+
+    Content objects can be serialised to bytes using the iter_bytes method.
+    If the Content-Type is recognised by other code, they are welcome to
+    look for richer contents that mere byte serialisation - for example in
+    memory object graphs etc. However, such code MUST be prepared to receive
+    a generic Content object that has been reconstructed from a byte stream.
+
+    :ivar content_type: The content type of this Content.
+    """
+
+    def __init__(self, content_type, get_bytes):
+        """Create a ContentType."""
+        if None in (content_type, get_bytes):
+            raise ValueError("None not permitted in %r, %r" % (
+                content_type, get_bytes))
+        self.content_type = content_type
+        self._get_bytes = get_bytes
+
+    def __eq__(self, other):
+        return (self.content_type == other.content_type and
+            ''.join(self.iter_bytes()) == ''.join(other.iter_bytes()))
+
+    def iter_bytes(self):
+        """Iterate over bytestrings of the serialised content."""
+        return self._get_bytes()
+
+    def iter_text(self):
+        """Iterate over the text of the serialised content.
+
+        This is only valid for text MIME types, and will use ISO-8859-1 if
+        no charset parameter is present in the MIME type. (This is somewhat
+        arbitrary, but consistent with RFC2617 3.7.1).
+
+        :raises ValueError: If the content type is not text/\*.
+        """
+        if self.content_type.type != "text":
+            raise ValueError("Not a text type %r" % self.content_type)
+        return self._iter_text()
+
+    def _iter_text(self):
+        """Worker for iter_text - does the decoding."""
+        encoding = self.content_type.parameters.get('charset', 'ISO-8859-1')
+        try:
+            # 2.5+
+            decoder = codecs.getincrementaldecoder(encoding)()
+            for bytes in self.iter_bytes():
+                yield decoder.decode(bytes)
+            final = decoder.decode(_b(''), True)
+            if final:
+                yield final
+        except AttributeError:
+            # < 2.5
+            bytes = ''.join(self.iter_bytes())
+            yield bytes.decode(encoding)
+
+    def __repr__(self):
+        return "<Content type=%r, value=%r>" % (
+            self.content_type, ''.join(self.iter_bytes()))
+
+
+class TracebackContent(Content):
+    """Content object for tracebacks.
+
+    This adapts an exc_info tuple to the Content interface.
+    text/x-traceback;language=python is used for the mime type, in order to
+    provide room for other languages to format their tracebacks differently.
+    """
+
+    def __init__(self, err, test):
+        """Create a TracebackContent for err."""
+        if err is None:
+            raise ValueError("err may not be None")
+        content_type = ContentType('text', 'x-traceback',
+            {"language": "python", "charset": "utf8"})
+        self._result = TestResult()
+        value = self._result._exc_info_to_string(err, test)
+        super(TracebackContent, self).__init__(
+            content_type, lambda: [value.encode("utf8")])