RFC - New experimental conversion tool skeleton. WIll replace oood and...

RFC - New experimental conversion tool skeleton. WIll replace oood and portal_transforms with a single tool which handles both conversion and metadata. In Phase 1, uses a single tool which calls itself through XML-RPC. In Phase 2, will be splitted into a tool and WSGI service.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@29497 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Converter/Converter.py

+# -*- coding: utf-8 -*-
+
+class Converter:
+  """
+    Converter classes implement document conversion
+    from a given format to another format.
+
+    ARCHITECTURE: because most document processing
+    software, and potentially libraries, are unstable,
+    do not always support multithreading and may lead
+    to memory leaks, the recommend approach to create 
+    a Converter is to simply execute a command with
+    popenX in a separate process and return the result.
+  """
+
+  # Introspection API Implementation
+  def getSourceFormatItemList(self):
+    """
+      Return the list of supported input format
+      (format, name)
+    """
+    raise NotImplementedError
+
+  def getDestinationFormatItemList(self):
+    """
+      Return the list of supported output format
+      (format, name)
+    """
+    raise NotImplementedError
+
+  # Conversion API Implementation
+  def convertFile(self, file, source_format, destination_format):
+    """
+    """
+    raise NotImplementedError
+
+  def getFileMetadataItemList(self, file, source_format):
+    """
+    """
+    raise NotImplementedError
+
+  def updateFileMetadata(self, file, source_format, **kw):
+    """
+    """
+    raise NotImplementedError

product/ERP5/Converter/OpenOffice.py

+# -*- coding: utf-8 -*-
+
+MAX_LAUNCH = 100
+
+class OpenOffice:
+
+  # Private methods
+  def _getAvailableOpenOfficeInstancePort(self):
+    """
+      This method starts a collection of
+      headless OpenOffice in bacground and attaches
+      them to the server process. Each time
+      a headless Openoffice is returned, a counter
+      is incremented. After MAX_LAUNCH times,
+      the server is closed and recreated.
+
+      The method returns a port number
+    """
+
+  def _getCommand(self, param):
+    """
+    """
+    return "/usr/bin/openoffice.convert %s"
+
+  # Introspection API Implementation
+  def getSourceFormatItemList(self):
+    """
+      Return the list of supported input format
+      (format, name)
+    """
+    port = self._getAvailableOpenOfficeInstancePort()
+
+  def getDestinationFormatItemList(self):
+    """
+      Return the list of supported output format
+      (format, name)
+    """
+    port = self._getAvailableOpenOfficeInstancePort()
+
+  # Conversion API Implementation
+  def convertFile(self, file, source_format, destination_format):
+    """
+    """
+    # XXX - just call a command line (python script)
+    #  which does all the work
+    port = self._getAvailableOpenOfficeInstancePort()
+    input, output = popen(self._getCommand('--convert'), file)
+
+  def getFileMetadataItemList(self, file, source_format):
+    """
+    """
+    # XXX - just call a command line (python script)
+    #  which does all the work
+    port = self._getAvailableOpenOfficeInstancePort()
+    input, output = popen(self._getCommand('--metadata'), file)
+
+  def updateFileMetadata(self, file, source_format, **kw):
+    """
+    """
+    # XXX - just call a command line (python script)
+    #  which does all the work
+    port = self._getAvailableOpenOfficeInstancePort()
+    input, output = popen(self._getCommand('--update'), file)

product/ERP5/Converter/bin/openoffice.convert

+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import pyuno
+
+# Invoke OpenOffice with appropriate port number provided by OpenOffice converter
+
+
+# Return result

product/ERP5/Tool/ConversionTool.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 responsability 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
+# garantees 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.
+#
+##############################################################################
+
+from Products.CMFCore.utils import getToolByName
+
+from AccessControl import ClassSecurityInfo
+from Globals import InitializeClass, DTMLFile
+from Products.CMFCore.utils import getToolByName
+from Products.ERP5Type import Permissions
+from Products.ERP5Type.Tool.BaseTool import BaseTool
+
+from Products.ERP5 import _dtmldir
+
+from zLOG import LOG
+
+class ConversionTool(BaseTool):
+  """
+    The ConversionTool class will provide in the future an 
+    API to unify file conversion and metadata handling in ERP5.
+
+    The first version consists of a tool which acts both as central
+    point for conversion services and metadata handling services
+    for all ERP5 Document classes and scripts, as well as a Web
+    Service for external applications.
+
+    The Tool calls itself, through XML-RPC protocol. A dedicated
+    Zope instance can be setup for handling conversions.
+
+    In the future, the tool will be splitted in 2 parts:
+      - a Tool
+      - a WSGI service
+
+    The tool reuses the portal_web_services to connect through
+    XML-RPC to the conversion server.
+
+    ARCHITECTURE PHASE 1: all Converter classes are stored 
+    in the Converter directory part of ERP5 Product. The tool
+    serves both as caller and recipient, and calls itself
+    through XML-RPC.
+
+    ARCHITECTURE PHASE 2: all Converter classes are moved to
+    a dedicated directory in /usr/share/oood/converter
+    (or new name). The Web Service API is moved away from
+    ConverterTool class and turned to a WSGI independent service
+
+    NOTE: this class is experimental and is subject to be removed
+    NOTE2: the code is only pseudo-code
+  """
+  id = 'portal_conversions'
+  meta_type = 'ERP5 Conversion Tool'
+  portal_type = 'Conversion Tool'
+  allowed_types = ()
+
+  # Declarative Security
+  security = ClassSecurityInfo()
+
+  #
+  #   ZMI methods
+  #
+  security.declareProtected( Permissions.ManagePortal, 'manage_overview' )
+  manage_overview = DTMLFile( 'explainConversionTool', _dtmldir )
+
+  def filtered_meta_types(self, user=None):
+    # Filters the list of available meta types.
+    all = SolverTool.inheritedAttribute('filtered_meta_types')(self)
+    meta_types = []
+    for meta_type in self.all_meta_types():
+      if meta_type['name'] in self.allowed_types:
+        meta_types.append(meta_type)
+    return meta_types
+
+  def tpValues(self):
+    """ show the content in the left pane of the ZMI """
+    return self.objectValues()
+
+  # Internal API - called by Document classes and scripts
+  def convert(self, file, source_format, destination_format, zip=False):
+    """
+      Returns the converted file in the given format
+  
+      zip parameter can be specified to return the result of conversion
+      in the form of a zip archive (which may contain multiple parts). 
+      This can be useful to convert a single ODF file to HMTL
+      and png images.
+    """
+    # Just call XML-RPC
+    preference_tool = getToolByName(self, 'portal_preferences')
+    web_service_tool = getToolByName(self, 'portal_web_services')
+    conversion_url = preference_tool.getPreferredConversionServiceUrl()
+    conversion_service = web_service_tool.connect(conversion_url)
+    # XXX - no exception handling - wrong
+    return conversion_service.convertFile(file, source_format, destination_format)
+
+
+  def getMetadataDict(self, file, source_format):
+    """
+      Returns a dict of metadata values for the
+      document. The structure of this dict is "unpredictable"
+      and follows the convention of each file.
+    """
+    # Just call XML-RPC
+    preference_tool = getToolByName(self, 'portal_preferences')
+    web_service_tool = getToolByName(self, 'portal_web_services')
+    conversion_url = preference_tool.getPreferredConversionServiceUrl()
+    conversion_service = web_service_tool.connect(conversion_url)
+    # XXX - no exception handling - wrong
+    return conversion_service.getFileMetadataItemList(file, source_format)
+
+
+  def updateMetadata(self, file, source_format, **kw):
+    """
+      Updates the file in the given source_format 
+      with provided metadata and return the resulting new file
+    """
+    # Just call XML-RPC
+    preference_tool = getToolByName(self, 'portal_preferences')
+    web_service_tool = getToolByName(self, 'portal_web_services')
+    conversion_url = preference_tool.getPreferredConversionServiceUrl()
+    conversion_service = web_service_tool.connect(conversion_url)
+    # XXX - no exception handling - wrong
+    return conversion_service.updateFileMetadata(file, source_format, **kw)
+
+
+  # Web Service API - called by any application through XML-RPC
+  # Will be removed in the future and moved to WSGI service
+  def convertFile(self, file, source_format, destination_format, zip=False):
+    """
+      Returns the converted file in the given format
+    """
+    converter = self._findConverter(source_format, destination_format)
+    return converter.convertFile(file, source_format, destination_format, zip=zip)
+
+
+  def getFileMetadataItemList(self, file, source_format):
+    """
+      Returns a list key, value pairs representing the 
+      metadata values for the document. The structure of this
+      list is "unpredictable" and follows the convention of each file.
+    """
+    converter = self._findConverter(source_format, destination_format)
+    return converter.getFileMetadataItemList(file, source_format)
+
+
+  def updateFileMetadata(self, file, source_format, **kw):
+    """
+      Updates the file in the given source_format 
+      with provided metadata and return the resulting new file
+    """
+    converter = self._findConverter(source_format, destination_format)
+    return converter.updateFileMetadata(file, source_format, destination_format, zip=zip)
+
+  # Private methods
+  def _findConverter(self, source_format, destination_format):
+    """
+      Browses all converter classes, initialised the repository of
+      converters and finds the appropriate class
+    """
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