z3c.conditionalviews 1.0

Integration with Zope

>>> import zope.component
>>> import zope.interface
>>> import z3c.conditionalviews.interfaces
>>> import z3c.conditionalviews.tests

Generic HTTP conditional publication

We can integrate the validation method with the publication call method. This as the effect of trying to validate every request that passes through the publications callObject method. This is useful to validate requests that modify objects so that the client can say modify this resource if it hasn’t changed since it last downloaded the resource, or if there is no existing resource at a location.

This has the added benifit in that we don’t have to specify how some one implements the PUT method.

>>> resp = http(r"""
... PUT /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... Content-type: text/plain
... Content-length: 55
... aaaaaaaaaa
... aaaaaaaaaa
... aaaaaaaaaa
... aaaaaaaaaa
... aaaaaaaaaa""", handle_errors = False)
>>> resp.getStatus()
201
>>> resp.getHeader('Content-length')
'0'
>>> resp.getHeader('Location')
'http://localhost/testfile'
>>> resp.getHeader('ETag', None) is None
True

We can now get the resource and the entity tag.

>>> resp = http(r"""
... GET /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
200
>>> resp.getHeader('ETag')
'"testfile:1"'
>>> print resp.getBody()
aaaaaaaaaa
aaaaaaaaaa
aaaaaaaaaa
aaaaaaaaaa
aaaaaaaaaa

We could have used the HEAD method to get the entity tag.

>>> resp = http(r"""
... HEAD /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
200
>>> resp.getHeader('ETag')
'"testfile:1"'

With no ‘If-None-Match’ header we override the data.

>>> resp = http(r"""
... PUT /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... Content-type: text/plain
... Content-length: 55
... bbbbbbbbbb
... bbbbbbbbbb
... bbbbbbbbbb
... bbbbbbbbbb
... bbbbbbbbbb""", handle_errors = False)
>>> resp.getStatus()
200
>>> resp.getHeader('Content-length')
'0'
>>> resp.getHeader('Location', None) is None
True
>>> resp.getHeader('ETag')
'"testfile:2"'

>>> resp = http(r"""
... GET /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
200
>>> print resp.getBody()
bbbbbbbbbb
bbbbbbbbbb
bbbbbbbbbb
bbbbbbbbbb
bbbbbbbbbb

Specifying a If-None-Match: “*” header, says to upload the data only if there is no resource at the location specified in the request URI. If there is a resource at the location then a 412 Precondition Failed response is returned and the resource is not modified’

>>> resp = http(r"""
... PUT /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... If-None-Match: "*"
... Content-type: text/plain
... Content-length: 55
... cccccccccc
... cccccccccc
... cccccccccc
... cccccccccc
... cccccccccc""")
>>> resp.getStatus()
412
>>> resp.getHeader('Content-length')
'0'
>>> resp.getHeader('Location', None) is None
True
>>> resp.getHeader('ETag')
'"testfile:2"'

The file does not change.

>>> resp = http(r"""
... GET /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
200
>>> print resp.getBody()
bbbbbbbbbb
bbbbbbbbbb
bbbbbbbbbb
bbbbbbbbbb
bbbbbbbbbb

And now since testfile2 does exist yet we content the content.

>>> resp = http(r"""
... PUT /testfile2 HTTP/1.1
... Authorization: Basic mgr:mgrpw
... If-None-Match: "*"
... Content-type: text/plain
... Content-length: 55
... yyyyyyyyyy
... yyyyyyyyyy
... yyyyyyyyyy
... yyyyyyyyyy
... yyyyyyyyyy""")
>>> resp.getStatus()
201
>>> resp.getHeader('Content-length')
'0'
>>> resp.getHeader('Location')
'http://localhost/testfile2'
>>> resp.getHeader('ETag', None) is None # No etag adapter is configured
True

>>> resp = http(r"""
... GET /testfile2 HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
200
>>> print resp.getBody()
yyyyyyyyyy
yyyyyyyyyy
yyyyyyyyyy
yyyyyyyyyy
yyyyyyyyyy

We can now delete the resource, only if it hasn’t changed. So for the ‘/testfile’ resource we can use its first entity tag to confirm this.

>>> resp = http(r"""
... DELETE /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... If-Match: "testfile:1"
... """)
>>> resp.getStatus()
412

And the file still exists.

>>> resp = http(r"""
... GET /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
200

But using a valid entity tag we can delete the resource.

>>> resp = http(r"""
... DELETE /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... If-Match: "testfile:2"
... """)
>>> resp.getStatus()
200
>>> resp.getBody()
''

>>> resp = http(r"""
... GET /testfile HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
404

Method not allowed

We should still get a 405 Method Not Allowed status for methods that aren’t registered yet.

We need to be logged in order to traverse to the file.

>>> resp = http(r"""
... FROG /testfile2 HTTP/1.1
... Authorization: Basic mgr:mgrpw
... """)
>>> resp.getStatus()
405
>>> resp.getHeader('ETag', None) is None
True

Cleanup

>>> zope.component.getGlobalSiteManager().unregisterAdapter(
...    SimpleEtag,
...    (zope.interface.Interface,
...     zope.publisher.interfaces.browser.IBrowserRequest,
...     zope.interface.Interface))
True

1.0 (2008-09-27)

• Using IDCTimes instead of IZopeDublinCore because IDCTimes is the actual required interface.

1.0b

• Fixed time zone issue in processing If-Modified protocol.

0.9

• Initial release.