Document.py

# -*- coding: utf-8 -*-
##############################################################################
#
# Copyright (c) 2009 Nexedi SA and Contributors. All Rights Reserved.
#                    Jean-Paul Smets-Solanes <jp@nexedi.com>
#
# WARNING: This program as such is intended to be used by professional
# programmers who take the whole responsibility of assessing all potential
# consequences resulting from its eventual inadequacies and bugs
# End users who are looking for a ready-to-use solution with commercial
# guarantees and support are strongly adviced to contract a Free Software
# Service Company
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
##############################################################################

import re, sys, os
from operator import add
from zLOG import LOG
from AccessControl import ClassSecurityInfo, getSecurityManager
from AccessControl.SecurityManagement import newSecurityManager, setSecurityManager
from Acquisition import aq_base
from Products.ERP5Type.Accessor.Constant import PropertyGetter as ConstantGetter
from Products.ERP5Type.Globals import get_request
from Products.CMFCore.utils import getToolByName, _checkPermission
from Products.ERP5Type import Permissions, PropertySheet, interfaces
from Products.ERP5Type.XMLObject import XMLObject
from Products.ERP5Type.DateUtils import convertDateToHour,\
                                number_of_hours_in_day, number_of_hours_in_year
from Products.ERP5Type.Utils import convertToUpperCase, fill_args_from_request
from Products.ERP5Type.TransactionalVariable import getTransactionalVariable
from Products.ERP5Type.ExtensibleTraversable import ExtensibleTraversableMixIn
from Products.ERP5Type.Cache import getReadOnlyTransactionCache
from Products.ERP5.Document.Url import UrlMixIn
from Products.ERP5.Tool.ContributionTool import MAX_REPEAT
from Products.ERP5Type.UnrestrictedMethod import unrestricted_apply
from Products.ZSQLCatalog.SQLCatalog import SQLQuery
from AccessControl import Unauthorized
import zope.interface
from Products.PythonScripts.Utility import allow_class
import tempfile
from subprocess import Popen, PIPE

# Mixin Import
from Products.ERP5.mixin.cached_convertable import CachedConvertableMixin
from Products.ERP5.mixin.text_convertable import TextConvertableMixin
from Products.ERP5.mixin.downloadable import DownloadableMixin
from Products.ERP5.mixin.document import DocumentMixin
from Products.ERP5.mixin.extensible_traversable import DocumentExtensibleTraversableMixin
from Products.ERP5.mixin.crawable import CrawableMixin

_MARKER = []
VALID_ORDER_KEY_LIST = ('user_login', 'content', 'file_name', 'input')

# these property ids are unchangable
FIXED_PROPERTY_IDS = ('id', 'uid', 'rid', 'sid')

# XXX: move to an easier to configure place (System Preference ?)
VALID_TEXT_FORMAT_LIST = ('text', 'txt', 'html', 'base_html',
                          'stripped-html')

VALID_IMAGE_FORMAT_LIST = ('jpg', 'jpeg', 'png', 'gif', 'pnm', 'ppm', 'tiff')

DEFAULT_DISPLAY_ID_LIST = ('nano', 'micro', 'thumbnail',
                            'xsmall', 'small', 'medium',
                            'large', 'large', 'xlarge',)

DEFAULT_QUALITY = 75

DEFAULT_CONTENT_TYPE = 'text/html'


class SnapshotMixin:
  """
    This class provides a generic API to store in the ZODB
    PDF snapshots of objects and documents with the
    goal to keep a facsimile copy of documents as they
    were at a given date.
  """

  # Declarative security
  security = ClassSecurityInfo()
  security.declareObjectProtected(Permissions.AccessContentsInformation)

  security.declareProtected(Permissions.ModifyPortalContent, 'createSnapshot')
  def createSnapshot(self):
    """
      Create a snapshot (PDF). This is the normal way to modifiy
      snapshot_data. Once a snapshot is taken, a new snapshot
      can not be taken.

      NOTE: use getSnapshotData and hasSnapshotData accessors
      to access a snapshot.

      NOTE2: implementation of createSnapshot should probably
      be delegated to a types base method since this it
      is configuration dependent.
    """
    if self.hasSnapshotData():
      raise ConversionError('This document already has a snapshot.')
    self._setSnapshotData(self.convert(format='pdf'))

  security.declareProtected(Permissions.ManagePortal, 'deleteSnapshot')
  def deleteSnapshot(self):
    """
      Deletes the snapshot - in theory this should never be done.
      It is there for programmers and system administrators.
    """
    try:
      del(self.snapshot_data)
    except AttributeError:
      pass

class ConversionError(Exception):pass

class DocumentProxyError(Exception):pass

class NotConvertedError(Exception):pass
allow_class(NotConvertedError)

class Document(DocumentExtensibleTraversableMixin, XMLObject, UrlMixIn, CachedConvertableMixin,
               SnapshotMixin, CrawableMixin, TextConvertableMixin,
               DownloadableMixin, DocumentMixin):
  """Document is an abstract class with all methods related to document
  management in ERP5. This includes searchable text, explicit relations,
  implicit relations, metadata, versions, languages, etc.

  Documents may either store their content directly or cache content
  which is retrieved from a specified URL. The second case if often
  referred as "External Document". Standalone "External Documents" may
  be created by specifying a URL to the contribution tool which is in
  charge of initiating the download process and selecting the appropriate
  document type. Groups of "External Documents" may also be generated from
  so-called "External Source" (refer to ExternalSource class for more
  information).

  External Documents may be downloaded once or updated at regular interval.
  The later can be useful to update the content of an external source.
  Previous versions may be stored in place or kept in a separate file.
  This feature is known as the crawling API. It is mostly implemented
  in ContributionTool with wrappers in the Document class. It can be useful
  for create a small search engine.

  There are currently two types of Document subclasses:

  * File for binary file based documents. File has subclasses such as Image,
    OOoDocument, PDFDocument, etc. to implement specific conversion methods.

  * TextDocument for text based documents. TextDocument has subclasses such
    as Wiki to implement specific methods. 
    TextDocument itself has a subclass (XSLTDocument) which provides
    XSLT based analysis and transformation of XML content based on XSLT
    templates. 

  Conversion should be achieved through the convert method and other methods
  of the conversion API (convertToBaseFormat, etc.).
  Moreover, any Document subclass must ne able to convert documents to text
  (asText method) and HTML (asHTML method). Text is required for full text
  indexing. HTML is required for crawling.

  Instances can be created directly, or via portal_contributions tool which
  manages document ingestion process whereby a file can be uploaded by http
  or sent in by email or dropped in by webdav or in some other way as yet
  unknown. The ingestion process has the following steps:

  (1) portal type detection
  (2) object creation and upload of data
  (3) metadata discovery (optionally with conversion of data to another format)
  (4) other possible actions to finalise the ingestion (ex. by assigning
      a reference)

  This class handles (3) and calls a ZMI script to do (4).

  Metadata can be drawn from various sources:

  input      -   data supplied with http request or set on the object during (2) (e.g.
                 discovered from email text)
  file_name  -   data which might be encoded in file name
  user_login -   information about user who is contributing the file
  content    -   data which might be derived from document content

  If a certain property is defined in more than one source, it is set according to
  preference order returned by a script 
     Document_getPreferredDocumentMetadataDiscoveryOrderList
     (or any type-based version since discovery is type dependent)

  Methods for discovering metadata are:

    getPropertyDictFromInput
    getPropertyDictFromFileName
    getPropertyDictFromUserLogin
    getPropertyDictFromContent

  Methods for processing content are implemented either in Document class
  or in Base class:

    getSearchableReferenceList (Base)
    getSearchableText (Base)
    index_html (overriden in Document subclasses)

  Methods for handling relations are implemented either in Document class
  or in Base class:

    getImplicitSuccessorValueList (Base)
    getImplicitPredecessorValueList (Base)
    getImplicitSimilarValueList (Base)
    getSimilarCloudValueList (Document)

  Implicit relations consist in finding document references inside
  searchable text (ex. INV-23456) and deducting relations from that.
  Two customisable methods required. One to find a list of implicit references
  inside the content (getSearchableReferenceList) and one to convert a given
  document reference into a list of reference strings which could be present
  in other content (asSearchableReferenceList).

  document.getSearchableReferenceList() returns
    [
     {'reference':' INV-12367'},
     {'reference': 'INV-1112', 'version':'012}', 
     {'reference': 'AB-CC-DRK', 'version':'011', 'language': 'en'}
    ]

  The Document class behaviour can be extended / customized through scripts
  (which are type-based so can be adjusted per portal type).

  * Document_getPropertyDictFromUserLogin - finds a user (by user_login or
    from session) and returns properties which should be set on the document

  * Document_getPropertyDictFromContent - analyzes document content and returns
    properties which should be set on the document

  * Base_getImplicitSuccessorValueList - finds appropriate all documents
    referenced in the current content

  * Base_getImplicitPredecessorValueList - finds document predecessors based on
    the document coordinates (can use only complete coordinates, or also partial)

  * Document_getPreferredDocumentMetadataDiscoveryOrderList - returns an order
    in which metadata should be set/overwritten

  * Document_finishIngestion - called by portal_activities after all the ingestion
    is completed (and after document has been converted, so text_content
    is available if the document has it)

  * Document_getNewRevision - calculates revision number which should be set
    on this document. Implementation depends on revision numbering policy which
    can be very different. Interaction workflow should call setNewRevision method.

  * Document_populateContent - analyses the document content and produces
    subcontent based on it (ex. images, news, etc.). This scripts can
    involve for example an XSLT transformation to process XML.

  Subcontent: documents may include subcontent (files, images, etc.)
  so that publication of rich content can be path independent. Subcontent
  can also be used to help the rendering in HTML of complex documents
  such as ODF documents.

  Consistency checking:
    Default implementation uses DocumentReferenceConstraint to check if the 
    reference/language/version triplet is unique. Additional constraints
    can be added if necessary.

  NOTE: Document.py supports a notion of revision which is very specific.
  The underlying concept is that, as soon as a document has a reference,
  the association of (reference, version, language) must be unique accross
  the whole system. This means that a given document in a given version in a
  given language is unique. The underlying idea is similar to the one in a Wiki
  system in which each page is unique and acts the the atom of collaboration.
  In the case of ERP5, if a team collaborates on a Text document written with
  an offline word processor, all updates should be placed inside the same object.
  A Contribution will thus modify an existing document, if allowed from security
  point of view, and increase the revision number. Same goes for properties
  (title). Each change generates a new revision.

    conversion API - not same as document - XXX BAD
    XXX make multiple interfaces

  TODO:
    - move all implementation bits to MixIn classes
    - in the end, Document class should have zero code
      and only serve as a quick and easy way to create 
      new types of documents (one could even consider 
      that this class should be trashed)
    - 
  """

  meta_type = 'ERP5 Document'
  portal_type = 'Document'
  add_permission = Permissions.AddPortalContent
  isDocument = ConstantGetter('isDocument', value=True)
  __dav_collection__=0

  zope.interface.implements(interfaces.IConvertable,
                            interfaces.ITextConvertable,
                            interfaces.IHtmlConvertable,
                            interfaces.ICachedConvertable,
                            interfaces.IVersionable,
                            interfaces.IDownloadable,
                            interfaces.ICrawlable,
                            interfaces.IDocument
                           )

  # Regular expressions
  href_parser = re.compile('<a[^>]*href=[\'"](.*?)[\'"]',re.IGNORECASE)
  body_parser = re.compile('<body[^>]*>(.*?)</body>', re.IGNORECASE + re.DOTALL)
  title_parser = re.compile('<title[^>]*>(.*?)</title>', re.IGNORECASE + re.DOTALL)
  base_parser = re.compile('<base[^>]*href=[\'"](.*?)[\'"][^>]*>', re.IGNORECASE + re.DOTALL)
  charset_parser = re.compile('(?P<keyword>charset="?)(?P<charset>[a-z0-9\-]+)', re.IGNORECASE)

  # Declarative security
  security = ClassSecurityInfo()
  security.declareObjectProtected(Permissions.AccessContentsInformation)

  # Declarative properties
  property_sheets = ( PropertySheet.Base
                    , PropertySheet.XMLObject
                    , PropertySheet.CategoryCore
                    , PropertySheet.DublinCore
                    , PropertySheet.Version
                    , PropertySheet.Document
                    , PropertySheet.ExternalDocument
                    , PropertySheet.Url
                    , PropertySheet.Periodicity
                    , PropertySheet.Snapshot
                    )

  searchable_property_list = ('asText', 'title', 'description', 'id', 'reference',
                              'version', 'short_title', 'subject',
                              'source_reference', 'source_project_title')


  security.declareProtected(Permissions.View, 'getSearchableText')
  def getSearchableText(self, md=None):
    """
      Used by the catalog for basic full text indexing.
      Uses searchable_property_list attribute to put together various properties
      of the document into one searchable text string.

      XXX-JPS - This method is nice. It should probably be moved to Base class
      searchable_property_list could become a standard class attribute.

      TODO (future): Make this property a per portal type property.
    """
    def getPropertyListOrValue(property):
      """
        we try to get a list, else we get value and convert to list
      """
      method = getattr(self, property, None)
      if method is not None:
        if callable(method):
          val = method()
          if isinstance(val, (list, tuple)):
            return list(val)
          return [str(val)]
      val = self.getPropertyList(property)
      if val is None:
        val = self.getProperty(property)
        if val is not None and val != '':
          val = [str(val)]
        else:
          val = []
      else:
        val = [str(v) for v in list(val) if v is not None]
      return val

    searchable_text = reduce(add, map(lambda x: getPropertyListOrValue(x),
                                                self.searchable_property_list))
    searchable_text = ' '.join(searchable_text)
    return searchable_text

  # Compatibility with CMF Catalog
  SearchableText = getSearchableText

  index_html = DownloadableMixin.index_html

  security.declareProtected(Permissions.AccessContentsInformation, 'isExternalDocument')
  def isExternalDocument(self):
    """
    Return true if this document was obtained from an external source
    """
    return bool(self.getUrlString())

  ### Relation getters
  security.declareProtected(Permissions.AccessContentsInformation, 'getSearchableReferenceList')
  def getSearchableReferenceList(self):
    """
      This method returns a list of dictionaries which can
      be used to find objects by reference. It uses for
      that a regular expression defined at system level
      preferences.
    """
    text = self.getSearchableText() # XXX getSearchableText or asText ?
    regexp = self.portal_preferences.getPreferredDocumentReferenceRegularExpression()
    try:
      rx_search = re.compile(regexp)
    except TypeError: # no regexp in preference
      LOG('ERP5/Document/Document.getSearchableReferenceList', 0,
          'Document regular expression must be set in portal preferences')
      return ()
    result = []
    tmp = {}
    for match in rx_search.finditer(text):
      group = match.group()
      group_item_list = match.groupdict().items()
      group_item_list.sort()
      key = (group, tuple(group_item_list))
      tmp[key] = None
    for group, group_item_tuple in tmp.keys():
      result.append((group, dict(group_item_tuple)))
    return result

  security.declareProtected(Permissions.AccessContentsInformation, 'getImplicitSuccessorValueList')
  def getImplicitSuccessorValueList(self):
    """
      Find objects which we are referencing (if our text_content contains
      references of other documents). The whole implementation is delegated to
      Base_getImplicitSuccessorValueList script.

      The implementation goes in 2 steps:

    - Step 1: extract with a regular expression
      a list of distionaries with various parameters such as
      reference, portal_type, language, version, user, etc. This
      part is configured through a portal preference.

    - Step 2: read the list of dictionaries
      and build a list of values by calling portal_catalog
      with appropriate parameters (and if possible build
      a complex query whenever this becomes available in
      portal catalog)

      The script is reponsible for calling getSearchableReferenceList
      so that it can use another approach if needed.

      NOTE: passing a group_by parameter may be useful at a
      later stage of the implementation.
    """
    tv = getTransactionalVariable(self) # XXX Performance improvement required
    cache_key = ('getImplicitSuccessorValueList', self.getPhysicalPath())
    try:
      return tv[cache_key]
    except KeyError:
      pass

    reference_list = [r[1] for r in self.getSearchableReferenceList()]
    result = self.Base_getImplicitSuccessorValueList(reference_list)
    tv[cache_key] = result
    return result

  security.declareProtected(Permissions.AccessContentsInformation, 'getImplicitPredecessorValueList')
  def getImplicitPredecessorValueList(self):
    """
      This function tries to find document which are referencing us - by reference only, or
      by reference/language etc. Implementation is passed to
        Base_getImplicitPredecessorValueList

      The script should proceed in two steps:

      Step 1: build a list of references out of the context
      (ex. INV-123456, 123456, etc.)

      Step 2: search using the portal_catalog and use
      priorities (ex. INV-123456 before 123456)
      ( if possible build  a complex query whenever
      this becomes available in portal catalog )

      NOTE: passing a group_by parameter may be useful at a
      later stage of the implementation.
    """
    return self._getTypeBasedMethod('getImplicitPredecessorValueList')()

  security.declareProtected(Permissions.AccessContentsInformation, 'getImplicitSimilarValueList')
  def getImplicitSimilarValueList(self):
    """
      Analyses content of documents to find out by the content which documents
      are similar. Not implemented yet.

      No cloud needed because transitive process
    """
    return []

  security.declareProtected(Permissions.AccessContentsInformation, 'getSimilarCloudValueList')
  def getSimilarCloudValueList(self, depth=0):
    """
      Returns all documents which are similar to us, directly or indirectly, and
      in both directions. In other words, it is a transitive closure of similar
      relation. Every document is returned in the latest version available.
    """
    lista = {}
    depth = int(depth)

    #gettername = 'get%sValueList' % convertToUpperCase(category)
    #relatedgettername = 'get%sRelatedValueList' % convertToUpperCase(category)

    def getRelatedList(ob, level=0):
      level += 1
      #getter = getattr(self, gettername)
      #relatedgetter = getattr(self, relatedgettername)
      #res = getter() + relatedgetter()
      res = ob.getSimilarValueList() + ob.getSimilarRelatedValueList()
      for r in res:
        if lista.get(r) is None:
          lista[r] = True # we use dict keys to ensure uniqueness
          if level != depth:
            getRelatedList(r, level)

    getRelatedList(self)
    lista_latest = {}
    for o in lista.keys():
      lista_latest[o.getLatestVersionValue()] = True # get latest versions avoiding duplicates again
    if lista_latest.has_key(self):
      lista_latest.pop(self) # remove this document
    if lista_latest.has_key(self.getLatestVersionValue()):
      # remove last version of document itself from related documents
      lista_latest.pop(self.getLatestVersionValue())

    return lista_latest.keys()

  ### Version and language getters - might be moved one day to a mixin class in base
  security.declareProtected(Permissions.View, 'getLatestVersionValue')
  def getLatestVersionValue(self, language=None):
    """
      Tries to find the latest version with the latest revision
      of self which the current user is allowed to access.

      If language is provided, return the latest document
      in the language.

      If language is not provided, return the latest version
      in original language or in the user language if the version is
      the same.
    """
    if not self.getReference():
      return self
    catalog = getToolByName(self.getPortalObject(), 'portal_catalog')
    kw = dict(reference=self.getReference(), sort_on=(('version','descending'),))
    if language is not None:
      kw['language'] = language
    result_list = catalog(**kw)

    original_language = self.getOriginalLanguage()
    user_language = self.Localizer.get_selected_language()

    # if language was given return it (if there are any docs in this language)
    if language is not None:
      try:
        return result_list[0].getObject()
      except IndexError:
        return None
    else:
      first = result_list[0].getObject()
      in_original = None
      for record in result_list:
        document = record.getObject()
        if document.getVersion() != first.getVersion():
          # we are out of the latest version - return in_original or first
          if in_original is not None:
            return in_original
          else:
            return first # this shouldn't happen in real life
        if document.getLanguage() == user_language:
          # we found it in the user language
          return document
        if document.getLanguage() == original_language:
          # this is in original language
          in_original = document
    # this is the only doc in this version
    return self

  security.declareProtected(Permissions.View, 'getVersionValueList')
  def getVersionValueList(self, version=None, language=None):
    """
      Returns a list of documents with same reference, same portal_type
      but different version and given language or any language if not given.
    """
    catalog = getToolByName(self.getPortalObject(), 'portal_catalog')
    kw = dict(portal_type=self.getPortalType(),
                   reference=self.getReference(),
                   sort_on=(('version', 'descending', 'SIGNED'),)
                  )
    if version:
      kw['version'] = version
    if language:
      kw['language'] = language
    return catalog(**kw)

  security.declareProtected(Permissions.AccessContentsInformation, 'isVersionUnique')
  def isVersionUnique(self):
    """
      Returns true if no other document exists with the same
      reference, version and language, or if the current
      document has no reference.
    """
    if not self.getReference():
      return True
    catalog = getToolByName(self.getPortalObject(), 'portal_catalog')
    self_count = catalog.unrestrictedCountResults(portal_type=self.getPortalDocumentTypeList(),
                                            reference=self.getReference(),
                                            version=self.getVersion(),
                                            language=self.getLanguage(),
                                            uid=self.getUid(),
                                            validation_state="!=cancelled"
                                            )[0][0]
    count = catalog.unrestrictedCountResults(portal_type=self.getPortalDocumentTypeList(),
                                            reference=self.getReference(),
                                            version=self.getVersion(),
                                            language=self.getLanguage(),
                                            validation_state="!=cancelled"
                                            )[0][0]
    # If self is not indexed yet, then if count == 1, version is not unique
    return count <= self_count

  security.declareProtected(Permissions.AccessContentsInformation, 'getRevision')
  def getRevision(self):
    """
      Returns the current revision by analysing the change log
      of the current object. The return value is a string
      in order to be consistent with the property sheet
      definition.
    """
    getInfoFor = getToolByName(self.getPortalObject(),
                                                  'portal_workflow').getInfoFor
    revision = len(getInfoFor(self, 'history', (), 'edit_workflow'))
    # XXX Also look at processing_status_workflow for compatibility.
    revision += len([history_item for history_item in\
                 getInfoFor(self, 'history', (), 'processing_status_workflow')\
                 if history_item.get('action') == 'edit'])
    return str(revision)

  security.declareProtected(Permissions.AccessContentsInformation, 'getRevisionList')
  def getRevisionList(self):
    """
      Returns the list of revision numbers of the current document
      by by analysing the change log of the current object.
    """
    return map(str, range(1, 1 + int(self.getRevision())))

  security.declareProtected(Permissions.ModifyPortalContent, 'mergeRevision')
  def mergeRevision(self):
    """
      Merge the current document with any previous revision
      or change its version to make sure it is still unique.

      NOTE: revision support is implemented in the Document
      class rather than within the ContributionTool
      because the ingestion process requires to analyse the content
      of the document first. Hence, it is not possible to
      do any kind of update operation until the whole ingestion
      process is completed, since update requires to know
      reference, version, language, etc. In addition,
      we have chosen to try to merge revisions after each
      metadata discovery as a way to make sure that any
      content added in the system through the ContributionTool
      (ex. through webdav) will be merged if necessary.
      It may be posssible though to split disoverMetadata and
      finishIngestion.
    """
    document = self
    catalog = getToolByName(self.getPortalObject(), 'portal_catalog')
    if self.getReference():
      # Find all document with same (reference, version, language)
      kw = dict(portal_type=self.getPortalDocumentTypeList(),
                reference=self.getReference(),
                where_expression=SQLQuery("validation_state NOT IN ('cancelled', 'deleted')"))
      if self.getVersion():
        kw['version'] = self.getVersion()
      if self.getLanguage():
        kw['language'] = self.getLanguage()
      document_list = catalog.unrestrictedSearchResults(**kw)
      existing_document = None
      # Select the first one which is not self and which
      # shares the same coordinates
      document_list = list(document_list)
      document_list.sort(key=lambda x: x.getId())
      for o in document_list:
        if o.getRelativeUrl() != self.getRelativeUrl() and\
           o.getVersion() == self.getVersion() and\
           o.getLanguage() == self.getLanguage():
          existing_document = o.getObject()
          break
      # We found an existing document to update
      if existing_document is not None:
        document = existing_document
        if existing_document.getPortalType() != self.getPortalType():
          raise ValueError, "[DMS] Ingestion may not change the type of an existing document"
        elif not _checkPermission(Permissions.ModifyPortalContent, existing_document):
          raise Unauthorized, "[DMS] You are not allowed to update the existing document which has the same coordinates (id %s)" % existing_document.getId()
        else:
          update_kw = {}
          for k in self.propertyIds():
            if k not in FIXED_PROPERTY_IDS and self.hasProperty(k):
              update_kw[k] = self.getProperty(k)
          existing_document.edit(**update_kw)
          # Erase self
          self.delete() # XXX Do we want to delete by workflow or for real ?
    return document

  security.declareProtected(Permissions.AccessContentsInformation, 'getLanguageList')
  def getLanguageList(self, version=None):
    """
      Returns a list of languages which this document is available in
      for the current user.
    """
    if not self.getReference(): return []
    catalog = getToolByName(self.getPortalObject(), 'portal_catalog')
    kw = dict(portal_type=self.getPortalType(),
              reference=self.getReference(),
              group_by=('language',))
    if version is not None:
      kw['version'] = version
    return map(lambda o:o.getLanguage(), catalog(**kw))

  security.declareProtected(Permissions.AccessContentsInformation, 'getOriginalLanguage')
  def getOriginalLanguage(self):
    """
      Returns the original language of this document.

      XXX-JPS not implemented yet ?
    """
    # Approach 1: use portal_catalog and creation dates
    # Approach 2: use workflow analysis (delegate to script if necessary)
    #             workflow analysis is the only way for multiple orginals
    # XXX - cache or set?
    reference = self.getReference()
    if not reference:
      return
    catalog = getToolByName(self.getPortalObject(), 'portal_catalog')
    res = catalog(reference=self.getReference(), sort_on=(('creation_date','ascending'),))
    # XXX this should be security-unaware - delegate to script with proxy roles
    return res[0].getLanguage() # XXX what happens if it is empty?

  ### Property getters
  # Property Getters are document dependent so that we can
  # handle the weird cases in which needed properties change with the type of document
  # and the usual cases in which accessing content changes with the meta type
  security.declareProtected(Permissions.ModifyPortalContent,'getPropertyDictFromUserLogin')
  def getPropertyDictFromUserLogin(self, user_login=None):
    """
      Based on the user_login, find out as many properties as needed.
      returns properties which should be set on the document
    """
    if user_login is None:
      user_login = str(getSecurityManager().getUser())
    method = self._getTypeBasedMethod('getPropertyDictFromUserLogin',
        fallback_script_id='Document_getPropertyDictFromUserLogin')
    return method(user_login)

  security.declareProtected(Permissions.ModifyPortalContent,'getPropertyDictFromContent')
  def getPropertyDictFromContent(self):
    """
      Based on the document content, find out as many properties as needed.
      returns properties which should be set on the document
    """
    # accesss data through convert
    mime, content = self.convert(None)
    if not content:
       # if document is empty, we will not find anything in its content
      return {}
    method = self._getTypeBasedMethod('getPropertyDictFromContent',
        fallback_script_id='Document_getPropertyDictFromContent')
    return method()

  security.declareProtected(Permissions.ModifyPortalContent,'getPropertyDictFromFileName')
  def getPropertyDictFromFileName(self, file_name):
    """
      Based on the file name, find out as many properties as needed.
      returns properties which should be set on the document
    """
    return self.portal_contributions.getPropertyDictFromFileName(file_name)

  security.declareProtected(Permissions.ModifyPortalContent,'getPropertyDictFromInput')
  def getPropertyDictFromInput(self):
    """
      Get properties which were supplied explicitly to the ingestion method
      (discovered or supplied before the document was created).

      The implementation consists in saving document properties
      into _backup_input by supposing that original input parameters were
      set on the document by ContributionTool.newContent as soon
      as the document was created.
    """
    kw = getattr(self, '_backup_input', {})
    if kw:
      return kw
    for id in self.propertyIds():
      # We should not consider file data
      if id not in ('data', 'categories_list', 'uid', 'id',
                    'text_content', 'base_data',) \
            and self.hasProperty(id):
        kw[id] = self.getProperty(id)
    self._backup_input = kw # We could use volatile and pass kw in activate
                            # if we are garanteed that _backup_input does not
                            # disappear within a given transaction
    return kw

  ### Metadata disovery and ingestion methods
  security.declareProtected(Permissions.ModifyPortalContent, 'discoverMetadata')
  def discoverMetadata(self, file_name=None, user_login=None):
    """
      This is the main metadata discovery function - controls the process
      of discovering data from various sources. The discovery itself is
      delegated to scripts or uses preference-configurable regexps. The
      method returns either self or the document which has been
      merged in the discovery process.

      file_name - this parameter is a file name of the form "AA-BBB-CCC-223-en"

      user_login - this is a login string of a person; can be None if the user is
                   currently logged in, then we'll get him from session
    """
    # Preference is made of a sequence of 'user_login', 'content', 'file_name', 'input'
    method = self._getTypeBasedMethod('getPreferredDocumentMetadataDiscoveryOrderList',
        fallback_script_id = 'Document_getPreferredDocumentMetadataDiscoveryOrderList')
    order_list = list(method())
    order_list.reverse()
    # build a dictionary according to the order
    kw = {}
    for order_id in order_list:
      result = None
      if order_id not in VALID_ORDER_KEY_LIST:
        # Prevent security attack or bad preferences
        raise AttributeError, "%s is not in valid order key list" % order_id
      method_id = 'getPropertyDictFrom%s' % convertToUpperCase(order_id)
      method = getattr(self, method_id)
      if order_id == 'file_name':
        if file_name is not None:
          result = method(file_name)
      elif order_id == 'user_login':
        if user_login is not None:
          result = method(user_login)
      else:
        result = method()
      if result is not None:
        kw.update(result)

    if file_name is not None:
      # filename is often undefined....
      kw['source_reference'] = file_name
    # Prepare the content edit parameters - portal_type should not be changed
    kw.pop('portal_type', None)
    # Try not to invoke an automatic transition here
    self._edit(**kw)
    # Finish ingestion by calling method
    self.finishIngestion() # XXX - is this really the right place ?
    self.reindexObject() # XXX - is this really the right place ?
    # Revision merge is tightly coupled
    # to metadata discovery - refer to the documentation of mergeRevision method
    merged_doc = self.mergeRevision() # XXX - is this really the right place ?
    merged_doc.reindexObject() # XXX - is this really the right place ?
    return merged_doc # XXX - is this really the right place ?

  security.declareProtected(Permissions.ModifyPortalContent, 'finishIngestion')
  def finishIngestion(self):
    """
      Finish the ingestion process by calling the appropriate script. This
      script can for example allocate a reference number automatically if
      no reference was defined.
    """
    method = self._getTypeBasedMethod('finishIngestion', fallback_script_id='Document_finishIngestion')
    return method()

  security.declareProtected(Permissions.View, 'asSubjectText')
  def asSubjectText(self, **kw):
    """
      Converts the subject of the document to a textual representation.
    """
    subject = self.getSubject('')
    if not subject:
      # XXX not sure if this fallback is a good idea.
      subject = self.getTitle('')
    return str(subject)

  security.declareProtected(Permissions.View, 'asEntireHTML')
  def asEntireHTML(self, **kw):
    """
      Returns a complete HTML representation of the document
      (with body tags, etc.). Adds if necessary a base
      tag so that the document can be displayed in an iframe
      or standalone.

      Actual conversion is delegated to _asHTML
    """
    html = self._asHTML(**kw)
    if self.getUrlString():
      # If a URL is defined, add the base tag
      # if base is defined yet.
      html = str(html)
      if not html.find('<base') >= 0:
        base = '<base href="%s"/>' % self.getContentBaseURL()
        html = html.replace('<head>', '<head>%s' % base, 1)
      self.setConversion(html, mime='text/html', format='base-html')
    return html

  security.declarePrivate('_asHTML')
  def _asHTML(self, **kw):
    """
      A private method which converts to HTML. This method
      is the one to override in subclasses.
    """
    kw['format'] = 'html'
    mime, html = self.convert(**kw)
    return html

  security.declareProtected(Permissions.View, 'asStrippedHTML')
  def asStrippedHTML(self, **kw):
    """
      Returns a stripped HTML representation of the document
      (without html and body tags, etc.) which can be used to inline
      a preview of the document.
    """
    return self._stripHTML(self._asHTML(**kw))

  security.declarePrivate('_guessEncoding')
  def _guessEncoding(self, string, mime='text/html'):
    """
      Try to guess the encoding for this string.
      Returns None if no encoding can be guessed.
    """
    try:
      import chardet
    except ImportError:
      chardet = None
    if chardet is not None and (mime == 'text/html'\
                                               or os.sys.platform != 'linux2'):
      # chardet works fine on html document and its platform independent
      return chardet.detect(string).get('encoding', None)
    else:
      # file command provide better result
      # for text/plain documents
      # store the content into tempfile
      file_descriptor, path = tempfile.mkstemp()
      file_object = os.fdopen(file_descriptor, 'w')
      file_object.write(string)
      file_object.close()
      # run file command against tempfile to and read encoded
      command_result = Popen(['file', '-b', '--mime-encoding', path],
                                                  stdout=PIPE).communicate()[0]
      # return detected encoding
      return command_result.strip()

  def _stripHTML(self, html, charset=None):
    """
      A private method which can be reused by subclasses
      to strip HTML content
    """
    body_list = re.findall(self.body_parser, str(html))
    if len(body_list):
      stripped_html = body_list[0]
    else:
      stripped_html = html
    return stripped_html

  security.declareProtected(Permissions.AccessContentsInformation, 'getContentInformation')
  def getContentInformation(self):
    """
    Returns the content information from the HTML conversion.
    The default implementation tries to build a dictionnary
    from the HTML conversion of the document and extract
    the document title.
    """
    result = {}
    html = self.asEntireHTML()
    if not html: return result
    title_list = re.findall(self.title_parser, str(html))
    if title_list:
      result['title'] = title_list[0]
    return result

  security.declareProtected(Permissions.AccessContentsInformation,
                            'getMetadataMappingDict')
  def getMetadataMappingDict(self):
    """
    Return a dict of metadata mapping used to update base metadata of the
    document
    """
    try:
      method = self._getTypeBasedMethod('getMetadataMappingDict')
    except KeyError, AttributeError:
      method = None
    if method is not None:
      return method()
    else:
      return {}

  # Transformation API
  security.declareProtected(Permissions.ModifyPortalContent, 'populateContent')
  def populateContent(self):
    """
      Populates the Document with subcontent based on the
      document base data.

      This can be used for example to transform the XML
      of an RSS feed into a single piece per news or
      to transform an XML export from a database into
      individual records. Other application: populate
      an HTML text document with its images, used in
      conversion with convertToBaseFormat.
    """
    try:
      method = self._getTypeBasedMethod('populateContent')
    except KeyError, AttributeError:
      method = None
    if method is not None: method()

  # Crawling API
  security.declareProtected(Permissions.AccessContentsInformation, 'getContentURLList')
  def getContentURLList(self):
    """
      Returns a list of URLs referenced by the content of this document.
      Default implementation consists in analysing the document
      converted to HTML. Subclasses may overload this method
      if necessary. However, it is better to extend the conversion
      methods in order to produce valid HTML, which is useful to
      many people, rather than overload this method which is only
      useful for crawling.
    """
    html_content = self.asStrippedHTML()
    return re.findall(self.href_parser, str(html_content))

  security.declareProtected(Permissions.ModifyPortalContent, 'updateContentFromURL')
  def updateContentFromURL(self, repeat=MAX_REPEAT, crawling_depth=0):
    """
      Download and update content of this document from its source URL.
      Implementation is handled by ContributionTool.
    """
    self.portal_contributions.updateContentFromURL(self, repeat=repeat, crawling_depth=crawling_depth)

  security.declareProtected(Permissions.ModifyPortalContent, 'crawlContent')
  def crawlContent(self):
    """
      Initialises the crawling process on the current document.
    """
    self.portal_contributions.crawlContent(self)

  security.declareProtected(Permissions.View, 'isIndexContent')
  def isIndexContent(self, container=None):
    """
      Ask container if we are and index, or a content.
      In the vast majority of cases we are content.
      This method is required in a crawling process to make
      a difference between URLs which return an index (ex. the
      list of files in remote server which is accessed through HTTP)
      and the files themselves.
    """
    if container is None:
      container = self.getParentValue()
    if hasattr(aq_base(container), 'isIndexContent'):
      return container.isIndexContent(self)
    return False

  security.declareProtected(Permissions.AccessContentsInformation, 'getContentBaseURL')
  def getContentBaseURL(self):
    """
      Returns the content base URL based on the actual content or
      on its URL.
    """
    base_url = self.asURL()
    base_url_list = base_url.split('/')
    if len(base_url_list):
      if base_url_list[-1] and base_url_list[-1].find('.') > 0:
        # Cut the trailing part in http://www.some.site/at/trailing.html
        # but not in http://www.some.site/at
        base_url = '/'.join(base_url_list[:-1])
    return base_url