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"""WebDAV support - null resource objects."""

__version__='$Revision: 1.24 $'[11:-2]

import sys, os, string, mimetypes, Globals
import Acquisition, OFS.content_types
from common import absattr, aq_base, urlfix
from AccessControl.Permission import Permission
from Resource import Resource
from Globals import Persistent


class NullResource(Persistent, Acquisition.Implicit, Resource):
    """Null resources are used to handle HTTP method calls on
    objects which do not yet exist in the url namespace."""

    __null_resource__=1

    __ac_permissions__=(
        ('View',                             ('HEAD',)),
        ('Add Documents, Images, and Files', ('PUT',)),
        ('Add Folders',                      ('MKCOL',)),
    )

    def __init__(self, parent, name, request=None):
        self.__name__=name
        self.__parent__=parent

    def __bobo_traverse__(self, REQUEST, name=None):
        # We must handle traversal so that we can recognize situations
        # where a 409 Conflict must be returned instead of the normal
        # 404 Not Found, per [WebDAV 8.3.1].
        try:    return getattr(self, name)
        except: pass
        method=REQUEST.get('REQUEST_METHOD', 'GET')
        if method in ('PUT', 'MKCOL'):
            raise 'Conflict', 'Collection ancestors must already exist.'
        raise 'Not Found', 'The requested resource was not found.'

    def HEAD(self, REQUEST, RESPONSE):
        """Retrieve resource information without a response message body."""
        self.dav__init(REQUEST, RESPONSE)
        raise 'Not Found', 'The requested resource does not exist.'

    # Most methods return 404 (Not Found) for null resources.
    DELETE=OPTIONS=TRACE=PROPFIND=PROPPATCH=COPY=MOVE=HEAD

    def _default_PUT_factory( self, name, typ, body ):
        #   Return DTMLDoc/Image/File, based on sniffing.
        from OFS.Image import Image, File
        from OFS.DTMLDocument import DTMLDocument
        if typ in ('text/html', 'text/xml', 'text/plain'):
            ob = DTMLDocument( '', __name__=name )
        elif typ[:6]=='image/':
            ob=Image(name, '', body, content_type=typ)
        else:
            ob=File(name, '', body, content_type=typ)
        return ob

    def PUT(self, REQUEST, RESPONSE):
        """Create a new non-collection resource."""
        self.dav__init(REQUEST, RESPONSE)

        name=self.__name__
        parent=self.__parent__
        body=REQUEST.get('BODY', '')
        typ=REQUEST.get_header('content-type', None)
        if typ is None:
            typ, enc=OFS.content_types.guess_content_type(name, body)

        factory = getattr( parent, 'PUT_factory'
                         , self._default_PUT_factory )
        ob = ( factory( name, typ, body )
            or self._default_PUT_factory( name, typ, body )
             )

        # Delegate actual PUT handling to the new object.
        ob.PUT( REQUEST, RESPONSE )
        self.__parent__._setObject(name, ob)
        RESPONSE.setStatus(201)
        RESPONSE.setBody('')
        return RESPONSE

    def MKCOL(self, REQUEST, RESPONSE):
        """Create a new collection resource."""
        self.dav__init(REQUEST, RESPONSE)
        if REQUEST.get('BODY', ''):
            raise 'Unsupported Media Type', 'Unknown request body.'
        parent=self.__parent__
        name=self.__name__
        if hasattr(aq_base(parent), name):
            raise 'Method Not Allowed', 'The name %s is in use.' % name
        if not hasattr(parent, '__dav_collection__'):
            raise 'Forbidden', 'Cannot create collection at this location.'
        parent.manage_addFolder(name)
        RESPONSE.setStatus(201)
        RESPONSE.setBody('')
        return RESPONSE



Globals.default__class_init__(NullResource)
