Image.py

##############################################################################
#
# Copyright (c) 2002 Zope Foundation and Contributors.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
"""Image object
"""

from cgi import escape
from cStringIO import StringIO
from mimetools import choose_boundary
import struct

from AccessControl.class_init import InitializeClass
from AccessControl.Permissions import change_images_and_files
from AccessControl.Permissions import view_management_screens
from AccessControl.Permissions import view as View
from AccessControl.Permissions import ftp_access
from AccessControl.Permissions import delete_objects
from AccessControl.SecurityInfo import ClassSecurityInfo
from Acquisition import Implicit
from App.special_dtml import DTMLFile
from DateTime.DateTime import DateTime
from Persistence import Persistent
from webdav.common import rfc1123_date
from webdav.interfaces import IWriteLock
from webdav.Lockable import ResourceLockedError
from ZPublisher import HTTPRangeSupport
from ZPublisher.HTTPRequest import FileUpload
from zExceptions import Redirect
from zope.contenttype import guess_content_type
from zope.interface import implementedBy
from zope.interface import implements

from OFS.Cache import Cacheable
from OFS.PropertyManager import PropertyManager
from OFS.role import RoleManager
from OFS.SimpleItem import Item_w__name__

from OFS.History import Historical
from OFS.History import html_diff

from zope.event import notify
from zope.lifecycleevent import ObjectModifiedEvent
from zope.lifecycleevent import ObjectCreatedEvent

manage_addFileForm = DTMLFile('dtml/imageAdd',
                              globals(),
                              Kind='File',
                              kind='file',
                             )
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, File(id,title,'',content_type, precondition))

    newFile = self._getOb(id)

    # 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:
        newFile.manage_upload(file)
    if content_type:
        newFile.content_type=content_type

    notify(ObjectCreatedEvent(newFile))

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


class File(Persistent, Implicit, PropertyManager,
           RoleManager, Item_w__name__, Historical, Cacheable):
    """A File object is a content object for arbitrary files."""

    implements(implementedBy(Persistent),
               implementedBy(Implicit),
               implementedBy(PropertyManager),
               implementedBy(RoleManager),
               implementedBy(Item_w__name__),
               implementedBy(Cacheable),
               IWriteLock,
               HTTPRangeSupport.HTTPRangeInterface,
              )
    meta_type='File'

    security = ClassSecurityInfo()
    security.declareObjectProtected(View)

    precondition=''
    size=None

    manage_editForm  =DTMLFile('dtml/fileEdit',globals(),
                               Kind='File',kind='file')
    manage_editForm._setName('manage_editForm')

    security.declareProtected(view_management_screens, 'manage')
    security.declareProtected(view_management_screens, 'manage_main')
    manage=manage_main=manage_editForm
    manage_uploadForm=manage_editForm

    manage_options=(
        (
        {'label': 'Edit', 'action': 'manage_main'},
        {'label': 'View', 'action': ''},
        )
        + PropertyManager.manage_options
        + RoleManager.manage_options
        + Item_w__name__.manage_options
        + Cacheable.manage_options
        + Historical.manage_options
        )

    _properties=({'id':'title', 'type': 'string'},
                 {'id':'content_type', 'type':'string'},
                 )

    def __init__(self, id, title, file, content_type='', precondition=''):
        self.__name__=id
        self.title=title
        self.precondition=precondition

        data, size = self._read_data(file)
        content_type=self._get_content_type(file, data, id, content_type)
        self.update_data(data, content_type, size)

    def id(self):
        return self.__name__

    def _if_modified_since_request_handler(self, REQUEST, RESPONSE):
        # HTTP If-Modified-Since header handling: return True if
        # we can handle this request by returning a 304 response
        header=REQUEST.get_header('If-Modified-Since', None)
        if header is not None:
            header=header.split( ';')[0]
            # Some proxies seem to send invalid date strings for this
            # header. If the date string is not valid, we ignore it
            # rather than raise an error to be generally consistent
            # with common servers such as Apache (which can usually
            # understand the screwy date string as a lucky side effect
            # of the way they parse it).
            # This happens to be what RFC2616 tells us to do in the face of an
            # invalid date.
            try:    mod_since=long(DateTime(header).timeTime())
            except: mod_since=None
            if mod_since is not None:
                if self._p_mtime:
                    last_mod = long(self._p_mtime)
                else:
                    last_mod = long(0)
                if last_mod > 0 and last_mod <= mod_since:
                    RESPONSE.setHeader('Last-Modified',
                                       rfc1123_date(self._p_mtime))
                    RESPONSE.setHeader('Content-Type', self.content_type)
                    RESPONSE.setHeader('Accept-Ranges', 'bytes')
                    RESPONSE.setStatus(304)
                    return True

    def _range_request_handler(self, REQUEST, RESPONSE):
        # HTTP Range header handling: return True if we've served a range
        # chunk out of our data.
        range = REQUEST.get_header('Range', None)
        request_range = REQUEST.get_header('Request-Range', None)
        if request_range is not None:
            # Netscape 2 through 4 and MSIE 3 implement a draft version
            # Later on, we need to serve a different mime-type as well.
            range = request_range
        if_range = REQUEST.get_header('If-Range', None)
        if range is not None:
            ranges = HTTPRangeSupport.parseRange(range)

            if if_range is not None:
                # Only send ranges if the data isn't modified, otherwise send
                # the whole object. Support both ETags and Last-Modified dates!
                if len(if_range) > 1 and if_range[:2] == 'ts':
                    # ETag:
                    if if_range != self.http__etag():
                        # Modified, so send a normal response. We delete
                        # the ranges, which causes us to skip to the 200
                        # response.
                        ranges = None
                else:
                    # Date
                    date = if_range.split( ';')[0]
                    try: mod_since=long(DateTime(date).timeTime())
                    except: mod_since=None
                    if mod_since is not None:
                        if self._p_mtime:
                            last_mod = long(self._p_mtime)
                        else:
                            last_mod = long(0)
                        if last_mod > mod_since:
                            # Modified, so send a normal response. We delete
                            # the ranges, which causes us to skip to the 200
                            # response.
                            ranges = None

            if ranges:
                # Search for satisfiable ranges.
                satisfiable = 0
                for start, end in ranges:
                    if start < self.size:
                        satisfiable = 1
                        break

                if not satisfiable:
                    RESPONSE.setHeader('Content-Range',
                        'bytes */%d' % self.size)
                    RESPONSE.setHeader('Accept-Ranges', 'bytes')
                    RESPONSE.setHeader('Last-Modified',
                        rfc1123_date(self._p_mtime))
                    RESPONSE.setHeader('Content-Type', self.content_type)
                    RESPONSE.setHeader('Content-Length', self.size)
                    RESPONSE.setStatus(416)
                    return True

                ranges = HTTPRangeSupport.expandRanges(ranges, self.size)

                if len(ranges) == 1:
                    # Easy case, set extra header and return partial set.
                    start, end = ranges[0]
                    size = end - start

                    RESPONSE.setHeader('Last-Modified',
                        rfc1123_date(self._p_mtime))
                    RESPONSE.setHeader('Content-Type', self.content_type)
                    RESPONSE.setHeader('Content-Length', size)
                    RESPONSE.setHeader('Accept-Ranges', 'bytes')
                    RESPONSE.setHeader('Content-Range',
                        'bytes %d-%d/%d' % (start, end - 1, self.size))
                    RESPONSE.setStatus(206) # Partial content

                    data = self.data
                    if isinstance(data, str):
                        RESPONSE.write(data[start:end])
                        return True

                    # Linked Pdata objects. Urgh.
                    pos = 0
                    while data is not None:
                        l = len(data.data)
                        pos = pos + l
                        if pos > start:
                            # We are within the range
                            lstart = l - (pos - start)

                            if lstart < 0: lstart = 0

                            # find the endpoint
                            if end <= pos:
                                lend = l - (pos - end)

                                # Send and end transmission
                                RESPONSE.write(data[lstart:lend])
                                break

                            # Not yet at the end, transmit what we have.
                            RESPONSE.write(data[lstart:])

                        data = data.next

                    return True

                else:
                    boundary = choose_boundary()

                    # Calculate the content length
                    size = (8 + len(boundary) + # End marker length
                        len(ranges) * (         # Constant lenght per set
                            49 + len(boundary) + len(self.content_type) +
                            len('%d' % self.size)))
                    for start, end in ranges:
                        # Variable length per set
                        size = (size + len('%d%d' % (start, end - 1)) +
                            end - start)


                    # Some clients implement an earlier draft of the spec, they
                    # will only accept x-byteranges.
                    draftprefix = (request_range is not None) and 'x-' or ''

                    RESPONSE.setHeader('Content-Length', size)
                    RESPONSE.setHeader('Accept-Ranges', 'bytes')
                    RESPONSE.setHeader('Last-Modified',
                        rfc1123_date(self._p_mtime))
                    RESPONSE.setHeader('Content-Type',
                        'multipart/%sbyteranges; boundary=%s' % (
                            draftprefix, boundary))
                    RESPONSE.setStatus(206) # Partial content

                    data = self.data
                    # The Pdata map allows us to jump into the Pdata chain
                    # arbitrarily during out-of-order range searching.
                    pdata_map = {}
                    pdata_map[0] = data

                    for start, end in ranges:
                        RESPONSE.write('\r\n--%s\r\n' % boundary)
                        RESPONSE.write('Content-Type: %s\r\n' %
                            self.content_type)
                        RESPONSE.write(
                            'Content-Range: bytes %d-%d/%d\r\n\r\n' % (
                                start, end - 1, self.size))

                        if isinstance(data, str):
                            RESPONSE.write(data[start:end])

                        else:
                            # Yippee. Linked Pdata objects. The following
                            # calculations allow us to fast-forward through the
                            # Pdata chain without a lot of dereferencing if we
                            # did the work already.
                            first_size = len(pdata_map[0].data)
                            if start < first_size:
                                closest_pos = 0
                            else:
                                closest_pos = (
                                    ((start - first_size) >> 16 << 16) +
                                    first_size)
                            pos = min(closest_pos, max(pdata_map.keys()))
                            data = pdata_map[pos]

                            while data is not None:
                                l = len(data.data)
                                pos = pos + l
                                if pos > start:
                                    # We are within the range
                                    lstart = l - (pos - start)

                                    if lstart < 0: lstart = 0

                                    # find the endpoint
                                    if end <= pos:
                                        lend = l - (pos - end)

                                        # Send and loop to next range
                                        RESPONSE.write(data[lstart:lend])
                                        break

                                    # Not yet at the end, transmit what we have.
                                    RESPONSE.write(data[lstart:])

                                data = data.next
                                # Store a reference to a Pdata chain link so we
                                # don't have to deref during this request again.
                                pdata_map[pos] = data

                    # Do not keep the link references around.
                    del pdata_map

                    RESPONSE.write('\r\n--%s--\r\n' % boundary)
                    return True

    security.declareProtected(View, 'index_html')
    def index_html(self, REQUEST, RESPONSE):
        """
        The default view of the contents of a File or Image.

        Returns the contents of the file or image.  Also, sets the
        Content-Type HTTP header to the objects content type.
        """

        if self._if_modified_since_request_handler(REQUEST, RESPONSE):
            # we were able to handle this by returning a 304
            # unfortunately, because the HTTP cache manager uses the cache
            # API, and because 304 responses are required to carry the Expires
            # header for HTTP/1.1, we need to call ZCacheable_set here.
            # This is nonsensical for caches other than the HTTP cache manager
            # unfortunately.
            self.ZCacheable_set(None)
            return ''

        if self.precondition and hasattr(self, str(self.precondition)):
            # Grab whatever precondition was defined and then
            # execute it.  The precondition will raise an exception
            # if something violates its terms.
            c=getattr(self, str(self.precondition))
            if hasattr(c,'isDocTemp') and c.isDocTemp:
                c(REQUEST['PARENTS'][1],REQUEST)
            else:
                c()

        if self._range_request_handler(REQUEST, RESPONSE):
            # we served a chunk of content in response to a range request.
            return ''

        RESPONSE.setHeader('Last-Modified', rfc1123_date(self._p_mtime))
        RESPONSE.setHeader('Content-Type', self.content_type)
        RESPONSE.setHeader('Content-Length', self.size)
        RESPONSE.setHeader('Accept-Ranges', 'bytes')

        if self.ZCacheable_isCachingEnabled():
            result = self.ZCacheable_get(default=None)
            if result is not None:
                # We will always get None from RAMCacheManager and HTTP
                # Accelerated Cache Manager but we will get
                # something implementing the IStreamIterator interface
                # from a "FileCacheManager"
                return result

        self.ZCacheable_set(None)

        data=self.data
        if isinstance(data, str):
            RESPONSE.setBase(None)
            return data

        while data is not None:
            RESPONSE.write(data.data)
            data=data.next

        return ''

    security.declareProtected(View, 'view_image_or_file')
    def view_image_or_file(self, URL1):
        """
        The default view of the contents of the File or Image.
        """
        raise Redirect, URL1

    security.declareProtected(View, 'PrincipiaSearchSource')
    def PrincipiaSearchSource(self):
        # Allow file objects to be searched.
        if self.content_type.startswith('text/'):
            return str(self.data)
        return ''

    security.declarePrivate('update_data')
    def update_data(self, data, content_type=None, size=None):
        if isinstance(data, unicode):
            raise TypeError('Data can only be str or file-like.  '
                            'Unicode objects are expressly forbidden.')

        if content_type is not None: self.content_type=content_type
        if size is None: size=len(data)
        self.size=size
        self.data=data
        self.ZCacheable_invalidate()
        self.ZCacheable_set(None)
        self.http__refreshEtag()

    security.declareProtected(change_images_and_files, 'manage_edit')
    def manage_edit(self, title, content_type, precondition='',
                    filedata=None, REQUEST=None):
        """
        Changes the title and content type attributes of the File or Image.
        """
        if self.wl_isLocked():
            raise ResourceLockedError, "File is locked via WebDAV"

        self.title=str(title)
        self.content_type=str(content_type)
        if precondition: self.precondition=str(precondition)
        elif self.precondition: del self.precondition
        if filedata is not None:
            self.update_data(filedata, content_type, len(filedata))
        else:
            self.ZCacheable_invalidate()

        notify(ObjectModifiedEvent(self))

        if REQUEST:
            message="Saved changes."
            return self.manage_main(self,REQUEST,manage_tabs_message=message)

    security.declareProtected(change_images_and_files, 'manage_upload')
    def manage_upload(self,file='',REQUEST=None):
        """
        Replaces the current contents of the File or Image object with file.

        The file or images contents are replaced with the contents of 'file'.
        """
        if self.wl_isLocked():
            raise ResourceLockedError, "File is locked via WebDAV"

        data, size = self._read_data(file)
        content_type=self._get_content_type(file, data, self.__name__,
                                            'application/octet-stream')
        self.update_data(data, content_type, size)

        notify(ObjectModifiedEvent(self))

        if REQUEST:
            message="Saved changes."
            return self.manage_main(self,REQUEST,manage_tabs_message=message)

    def manage_historyCompare(self, rev1, rev2, REQUEST,
                              historyComparisonResults=''):
        if self.content_type and ((
                self.content_type.startswith('text') or
                self.content_type.endswith('javascript'))
                and self.get_size() < 65536):
            return File.inheritedAttribute('manage_historyCompare')(
                self, rev1, rev2, REQUEST,
                historyComparisonResults=html_diff(
                    str(rev1.data),
                    str(rev2.data)))
        return File.inheritedAttribute('manage_historyCompare')(
            self, rev1, rev2, REQUEST,
            historyComparisonResults=historyComparisonResults)

    def _get_content_type(self, file, body, id, content_type=None):
        headers=getattr(file, 'headers', None)
        if headers and 'content-type' in headers:
            content_type=headers['content-type']
        else:
            if not isinstance(body, str): body=body.data
            content_type, enc=guess_content_type(
                getattr(file, 'filename',id), body, content_type)
        return content_type

    def _read_data(self, file):
        import transaction

        n=1 << 16

        if isinstance(file, str):
            size=len(file)
            if size < n: return file, size
            # Big string: cut it into smaller chunks
            file = StringIO(file)

        if isinstance(file, FileUpload) and not file:
            raise ValueError, 'File not specified'

        if hasattr(file, '__class__') and file.__class__ is Pdata:
            size=len(file)
            return file, size

        seek=file.seek
        read=file.read

        seek(0,2)
        size=end=file.tell()

        if size <= 2*n:
            seek(0)
            if size < n: return read(size), size
            return Pdata(read(size)), size

        # Make sure we have an _p_jar, even if we are a new object, by
        # doing a sub-transaction commit.
        transaction.savepoint(optimistic=True)

        if self._p_jar is None:
            # Ugh
            seek(0)
            return Pdata(read(size)), size

        # Now we're going to build a linked list from back
        # to front to minimize the number of database updates
        # and to allow us to get things out of memory as soon as
        # possible.
        next = None
        while end > 0:
            pos = end-n
            if pos < n:
                pos = 0 # we always want at least n bytes
            seek(pos)

            # Create the object and assign it a next pointer
            # in the same transaction, so that there is only
            # a single database update for it.
            data = Pdata(read(end-pos))
            self._p_jar.add(data)
            data.next = next

            # Save the object so that we can release its memory.
            transaction.savepoint(optimistic=True)
            data._p_deactivate()
            # The object should be assigned an oid and be a ghost.
            assert data._p_oid is not None
            assert data._p_state == -1

            next = data
            end = pos

        return next, size

    security.declareProtected(delete_objects, 'DELETE')

    security.declareProtected(change_images_and_files, 'PUT')
    def PUT(self, REQUEST, RESPONSE):
        """Handle HTTP PUT requests"""
        self.dav__init(REQUEST, RESPONSE)
        self.dav__simpleifhandler(REQUEST, RESPONSE, refresh=1)
        type=REQUEST.get_header('content-type', None)

        file=REQUEST['BODYFILE']

        data, size = self._read_data(file)
        content_type=self._get_content_type(file, data, self.__name__,
                                            type or self.content_type)
        self.update_data(data, content_type, size)

        RESPONSE.setStatus(204)
        return RESPONSE

    security.declareProtected(View, 'get_size')
    def get_size(self):
        # Get the size of a file or image.
        # Returns the size of the file or image.
        size=self.size
        if size is None: size=len(self.data)
        return size

    # deprecated; use get_size!
    getSize=get_size

    security.declareProtected(View, 'getContentType')
    def getContentType(self):
        # Get the content type of a file or image.
        # Returns the content type (MIME type) of a file or image.
        return self.content_type


    def __str__(self): return str(self.data)
    def __len__(self): return 1

    security.declareProtected(ftp_access, 'manage_FTPstat')
    security.declareProtected(ftp_access, 'manage_FTPlist')

    security.declareProtected(ftp_access, 'manage_FTPget')
    def manage_FTPget(self):
        """Return body for ftp."""
        RESPONSE = self.REQUEST.RESPONSE

        if self.ZCacheable_isCachingEnabled():
            result = self.ZCacheable_get(default=None)
            if result is not None:
                # We will always get None from RAMCacheManager but we will get
                # something implementing the IStreamIterator interface
                # from FileCacheManager.
                # the content-length is required here by HTTPResponse, even
                # though FTP doesn't use it.
                RESPONSE.setHeader('Content-Length', self.size)
                return result

        data = self.data
        if isinstance(data, str):
            RESPONSE.setBase(None)
            return data

        while data is not None:
            RESPONSE.write(data.data)
            data = data.next

        return ''

InitializeClass(File)


manage_addImageForm=DTMLFile('dtml/imageAdd',globals(),
                             Kind='Image',kind='image')
def manage_addImage(self, id, file, title='', precondition='', content_type='',
                    REQUEST=None):
    """
    Add a new Image object.

    Creates a new Image 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 image without data:
    self._setObject(id, Image(id,title,'',content_type, precondition))

    newFile = self._getOb(id)

    # 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:
        newFile.manage_upload(file)
    if content_type:
        newFile.content_type=content_type

    notify(ObjectCreatedEvent(newFile))

    if REQUEST is not None:
        try:    url=self.DestinationURL()
        except: url=REQUEST['URL1']
        REQUEST.RESPONSE.redirect('%s/manage_main' % url)
    return id


def getImageInfo(data):
    data = str(data)
    size = len(data)
    height = -1
    width = -1
    content_type = ''

    # handle GIFs
    if (size >= 10) and data[:6] in ('GIF87a', 'GIF89a'):
        # Check to see if content_type is correct
        content_type = 'image/gif'
        w, h = struct.unpack("<HH", data[6:10])
        width = int(w)
        height = int(h)

    # See PNG v1.2 spec (http://www.cdrom.com/pub/png/spec/)
    # Bytes 0-7 are below, 4-byte chunk length, then 'IHDR'
    # and finally the 4-byte width, height
    elif ((size >= 24) and (data[:8] == '\211PNG\r\n\032\n')
          and (data[12:16] == 'IHDR')):
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[16:24])
        width = int(w)
        height = int(h)

    # Maybe this is for an older PNG version.
    elif (size >= 16) and (data[:8] == '\211PNG\r\n\032\n'):
        # Check to see if we have the right content type
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[8:16])
        width = int(w)
        height = int(h)

    # handle JPEGs
    elif (size >= 2) and (data[:2] == '\377\330'):
        content_type = 'image/jpeg'
        jpeg = StringIO(data)
        jpeg.read(2)
        b = jpeg.read(1)
        try:
            while (b and ord(b) != 0xDA):
                while (ord(b) != 0xFF): b = jpeg.read(1)
                while (ord(b) == 0xFF): b = jpeg.read(1)
                if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
                    jpeg.read(3)
                    h, w = struct.unpack(">HH", jpeg.read(4))
                    break
                else:
                    jpeg.read(int(struct.unpack(">H", jpeg.read(2))[0])-2)
                b = jpeg.read(1)
            width = int(w)
            height = int(h)
        except: pass

    return content_type, width, height


class Image(File):
    """Image objects can be GIF, PNG or JPEG and have the same methods
    as File objects.  Images also have a string representation that
    renders an HTML 'IMG' tag.
    """
    meta_type='Image'

    security = ClassSecurityInfo()
    security.declareObjectProtected(View)

    alt=''
    height=''
    width=''

    # FIXME: Redundant, already in base class
    security.declareProtected(change_images_and_files, 'manage_edit')
    security.declareProtected(change_images_and_files, 'manage_upload')
    security.declareProtected(change_images_and_files, 'PUT')
    security.declareProtected(View, 'index_html')
    security.declareProtected(View, 'get_size')
    security.declareProtected(View, 'getContentType')
    security.declareProtected(ftp_access, 'manage_FTPstat')
    security.declareProtected(ftp_access, 'manage_FTPlist')
    security.declareProtected(ftp_access, 'manage_FTPget')
    security.declareProtected(delete_objects, 'DELETE')

    _properties=({'id':'title', 'type': 'string'},
                 {'id':'alt', 'type':'string'},
                 {'id':'content_type', 'type':'string','mode':'w'},
                 {'id':'height', 'type':'string'},
                 {'id':'width', 'type':'string'},
                 )

    manage_options=(
        ({'label':'Edit', 'action':'manage_main'},
         {'label':'View', 'action':'view_image_or_file'}, )
        + PropertyManager.manage_options
        + RoleManager.manage_options
        + Item_w__name__.manage_options
        + Cacheable.manage_options
        )

    manage_editForm  =DTMLFile('dtml/imageEdit',globals(),
                               Kind='Image',kind='image')
    manage_editForm._setName('manage_editForm')

    security.declareProtected(View, 'view_image_or_file')
    view_image_or_file =DTMLFile('dtml/imageView',globals())

    security.declareProtected(view_management_screens, 'manage')
    security.declareProtected(view_management_screens, 'manage_main')
    manage=manage_main=manage_editForm
    manage_uploadForm=manage_editForm

    security.declarePrivate('update_data')
    def update_data(self, data, content_type=None, size=None):
        if isinstance(data, unicode):
            raise TypeError('Data can only be str or file-like.  '
                            'Unicode objects are expressly forbidden.')

        if size is None: size=len(data)

        self.size=size
        self.data=data

        ct, width, height = getImageInfo(data)
        if ct:
            content_type = ct
        if width >= 0 and height >= 0:
            self.width = width
            self.height = height

        # Now we should have the correct content type, or still None
        if content_type is not None: self.content_type = content_type

        self.ZCacheable_invalidate()
        self.ZCacheable_set(None)
        self.http__refreshEtag()

    def __str__(self):
        return self.tag()

    security.declareProtected(View, 'tag')
    def tag(self, height=None, width=None, alt=None,
            scale=0, xscale=0, yscale=0, css_class=None, title=None, **args):
        #Generate an HTML IMG tag for this image, with customization.
        #Arguments to self.tag() can be any valid attributes of an IMG tag.
        #'src' will always be an absolute pathname, to prevent redundant
        #downloading of images. Defaults are applied intelligently for
        #'height', 'width', and 'alt'. If specified, the 'scale', 'xscale',
        #and 'yscale' keyword arguments will be used to automatically adjust
        #the output height and width values of the image tag.

        #Since 'class' is a Python reserved word, it cannot be passed in
        #directly in keyword arguments which is a problem if you are
        #trying to use 'tag()' to include a CSS class. The tag() method
        #will accept a 'css_class' argument that will be converted to
        #'class' in the output tag to work around this.

        if height is None: height=self.height
        if width is None:  width=self.width

        # Auto-scaling support
        xdelta = xscale or scale
        ydelta = yscale or scale

        if xdelta and width:
            width =  str(int(round(int(width) * xdelta)))
        if ydelta and height:
            height = str(int(round(int(height) * ydelta)))

        result='<img src="%s"' % (self.absolute_url())

        if alt is None:
            alt=getattr(self, 'alt', '')
        result = '%s alt="%s"' % (result, escape(alt, 1))

        if title is None:
            title=getattr(self, 'title', '')
        result = '%s title="%s"' % (result, escape(title, 1))

        if height:
            result = '%s height="%s"' % (result, height)

        if width:
            result = '%s width="%s"' % (result, width)

        # Omitting 'border' attribute (Collector #1557)
#        if not 'border' in [ x.lower() for x in  args.keys()]:
#            result = '%s border="0"' % result

        if css_class is not None:
            result = '%s class="%s"' % (result, css_class)

        for key in args.keys():
            value = args.get(key)
            if value:
                result = '%s %s="%s"' % (result, key, value)

        return '%s />' % result

InitializeClass(Image)


def cookId(id, title, file):
    if not id and hasattr(file,'filename'):
        filename=file.filename
        title=title or filename
        id=filename[max(filename.rfind('/'),
                        filename.rfind('\\'),
                        filename.rfind(':'),
                        )+1:]
    return id, title

class Pdata(Persistent, Implicit):
    # Wrapper for possibly large data

    next=None

    def __init__(self, data):
        self.data=data

    def __getslice__(self, i, j):
        return self.data[i:j]

    def __len__(self):
        data = str(self)
        return len(data)

    def __str__(self):
        next=self.next
        if next is None: return self.data

        r=[self.data]
        while next is not None:
            self=next
            r.append(self.data)
            next=self.next

        return ''.join(r)