[Zope-CMF] caching policy manager

[Dieter Maurer]

Jens Vagelpohl wrote at 2006-9-13 09:15 +0200:
> ...
>It is a long-standing bug that the CMFDefault File index_html (and  
>download, which is obsolete in newer CMF versions) simply defers to  
>index_html from OFS.File. That one doesn't know anything about Cache  
>Policy Managers, it only deals with the Zope ZCacheable cache manager  
>mechanism.

I have defined CMF-aware ZODB object types. The one for "File" looks
like this:

# DM 2005-11-02: added
""" CMF 'File' variant (CMF Cache Policy Manager aware)"""

from OFS.Image import File, manage_addFileForm, cookId

from utils import _setCacheHeaders, _ViewEmulator

class CMFFile(File):
    '''CMF cache policy manager aware file.'''
    meta_type = 'CPM aware File'

    def index_html(self, REQUEST, RESPONSE):
        ' '
        r = File.index_html(self, REQUEST, RESPONSE)
        if self.ZCacheable_getManager() is None:
            # not none cache manager already taken care of
            _setCacheHeaders(self._getCPMCachingWrapper(), extra_context={})
        return r

    # DM 2006-05-17: more modular CPM caching
    def _getCPMCachingWrapper(self):
        return _ViewEmulator().__of__(self)
      

# essentially a copy of "OFS.Image.manage_addFile" -- we should probably
# use "ReuseUtils".
def manage_addFile(self,id,file='',title='',precondition='', content_type='',
                   REQUEST=None):
    """Add a new File object.

    Creates a new File object 'id' with the contents of 'file'"""

    id=str(id)
    title=str(title)
    content_type=str(content_type)
    precondition=str(precondition)

    id, title = cookId(id, title, file)

    self=self.this()

    # First, we create the file without data:
    self._setObject(id, CMFFile(id,title,'',content_type, precondition))

    # Now we "upload" the data.  By doing this in two steps, we
    # can use a database trick to make the upload more efficient.
    if file:
        self._getOb(id).manage_upload(file)
    if content_type:
        self._getOb(id).content_type=content_type

    if REQUEST is not None:
        REQUEST['RESPONSE'].redirect(self.absolute_url()+'/manage_main')


def initialize(context):
    context.registerClass(
        CMFFile,
        permission='Add Documents, Images, and Files',
        constructors=(manage_addFileForm,
                      manage_addFile),
        )



-- 
Dieter