StreamView is broken

[1letter]

I get a traceback if the Video Source should be played.

Traceback (most recent call last):
  File "/Development/Plone/SOSNET/eggs/waitress-1.4.4-py3.8.egg/waitress/channel.py", line 350, in service
    task.service()
  File "/Development/Plone/SOSNET/eggs/waitress-1.4.4-py3.8.egg/waitress/task.py", line 171, in service
    self.execute()
  File "/Development/Plone/SOSNET/eggs/waitress-1.4.4-py3.8.egg/waitress/task.py", line 441, in execute
    app_iter = self.channel.server.application(environ, start_response)
  File "/Development/Plone/SOSNET/eggs/Paste-3.4.1-py3.8.egg/paste/translogger.py", line 69, in __call__
    return self.application(environ, replacement_start_response)
  File "/Development/Plone/SOSNET/eggs/Zope-4.5-py3.8.egg/ZPublisher/httpexceptions.py", line 30, in __call__
    return self.application(environ, start_response)
  File "/Development/Plone/SOSNET/eggs/Zope-4.5-py3.8.egg/ZPublisher/WSGIPublisher.py", line 377, in publish_module
    status, headers = response.finalize()
  File "/Development/Plone/SOSNET/eggs/Zope-4.5-py3.8.egg/ZPublisher/HTTPResponse.py", line 1056, in finalize
    self.setHeader('content-length', len(self.body))
TypeError: object of type 'filestream_range_iterator' has no len()

• The View /test1/@@view/++widget++form.widgets.IVideo.video_file/@@stream is the MediaStream class in widget.py .
• It use a helper methdod of plone.namedfile.utils .
• The filestream_range_iterator implements IStreamIterator from ZPublisher.Iterators

But the interface IStreamIterator required a method __ len __() per definition. It's not implemented in the filestream_range_iterator.

Versions:
plone.namedfile 5.4.0
wildcard.media 2.1.0
Plone 5.2.2 py3

[ale-rt]

I recently added this plone/plone.dexterity#139 to plone.dexterity.
What happens if you pin plone.dexterity 2.10.0?

[1letter]

That doesn't help. I pinned the version to 2.10.0 and run the buildout. But the error don't go away.

[ale-rt]

You are right, I did not notice it was another adapter:
https://github.com/plone/plone.namedfile/blob/14c1a3539cee99c3983adeb28eca5117272b7591/plone/namedfile/utils/__init__.py#L74-L75
Anyway the fix should be similar to plone/plone.dexterity#139

[1letter]

i will check it. thanks for hint

[1letter]

i think it's a incorrect interface @ale-rt , see here my comment

[mamico]

filestream_range_iterator is a pseudo stream implementation, you need to have all the file available, but you can expose parts of them using HTTP Range headers. I was wondering why a similar issue was not reported in plone.namedilfe, so I double-checked and found differences between here and plone.namedfile. @1letter please check if #78 solves the issue.