Class StreamingHttpResponse

django/http/response.py:443–547

A streaming HTTP response class with an iterator as content. This should only be iterated once, when the response is streamed to the client. However, it can be appended to or replaced with a new iterator that wraps the original content (or yields entirely new content).

class StreamingHttpResponse(HttpResponseBase):
    """
    A streaming HTTP response class with an iterator as content.

    This should only be iterated once, when the response is streamed to the
    client. However, it can be appended to or replaced with a new iterator
    that wraps the original content (or yields entirely new content).
    """

    streaming = True

    def __init__(self, streaming_content=(), *args, **kwargs):
        super().__init__(*args, **kwargs)
        # `streaming_content` should be an iterable of bytestrings.
        # See the `streaming_content` property methods.
        self.streaming_content = streaming_content

    def __repr__(self):
        return "<%(cls)s status_code=%(status_code)d%(content_type)s>" % {
            "cls": self.__class__.__qualname__,
            "status_code": self.status_code,
            "content_type": self._content_type_for_repr,
        }

    @property
    def content(self):
        raise AttributeError(
            "This %s instance has no `content` attribute. Use "
            "`streaming_content` instead." % self.__class__.__name__
        )

    @property
    def text(self):
        raise AttributeError(
            "This %s instance has no `text` attribute." % self.__class__.__name__
        )

    @property
    def streaming_content(self):
        if self.is_async:
            # pull to lexical scope to capture fixed reference in case
            # streaming_content is set again later.
            _iterator = self._iterator

            async def awrapper():
                async for part in _iterator:
                    yield self.make_bytes(part)

            return awrapper()
        else:
            return map(self.make_bytes, self._iterator)

    @streaming_content.setter
    def streaming_content(self, value):
        self._set_streaming_content(value)

    def _set_streaming_content(self, value):
        # Ensure we can never iterate on "value" more than once.