Add erp5.component.extension as a dynamic module where extensions are lazily loaded.

product/ERP5Type/Core/DocumentComponent.py

 # -*- coding: utf-8 -*-
 ##############################################################################
 #
-# Copyright (c) 2010 Nexedi SA and Contributors. All Rights Reserved.
+# Copyright (c) 2012 Nexedi SA and Contributors. All Rights Reserved.
+#                    Arnaud Fontaine <arnaud.fontaine@nexedi.com>
+#                    Jean-Paul Smets <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
@@ -26,6 +28,9 @@
 #
 ##############################################################################
 
+import imp
+import os
+
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions
 from Products.ERP5Type.Base import Base
@@ -53,15 +58,20 @@ class DocumentComponent(Base):
                        'Reference',
                        'TextDocument')
 
-    def loadComponent(self):
-      """
-      """
-      from Products.ERP5Type.Utils import importLocalDocument
+    def load(self):
+      # XXX-arnau: There should be a load_source() taking a string rather than
+      # creating a temporary file
       from App.config import getConfiguration
       instance_home = getConfiguration().instancehome
-      path = '%s/component/document' % instance_home
-      component_path = '%s/%s.py' % (path, self.getReference()) # using ID would be better... with some extensions in importLocalDocument
-      component_file = open(component_path, 'w')
+      path = '%s/Component' % instance_home
+      if not os.path.isdir(path):
+        os.mkdir(path)
+
+      component_path = '%s/%s.py' % (path, self.getId())
+      with open(component_path, 'w') as component_file:
         component_file.write(self.getTextContent())
-      component_file.close()
-      importLocalDocument(self.getReference(), path=path)
+
+      try:
+        return imp.load_source(self.getReference(), component_path)
+      finally:
+        os.remove(component_path)

product/ERP5Type/Tool/ComponentTool.py

@@ -27,88 +27,19 @@
 #
 ##############################################################################
 
-
-""" Component Tool module for ERP5 """
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type.Tool.BaseTool import BaseTool
 from Products.ERP5Type import Permissions
 
-class ComponentLoader:
-  """
-    A callable class which delegates component load to ComponentTool
-    and which contains attributes which can either be called or
-    implement default component access for different types of components
-  """
-  def __init__(self):
-    self.component = self
-    # This could be automated by introspecting 
-    # portal_types and listing all component types
-    self.document = TypedComponentLoader('Document Component')
-    self.interface = TypedComponentLoader('Interface Component')
-    self.mixin = TypedComponentLoader('Mixin Component')
-    self.accessor = TypedComponentLoader('Accessor Component')
-    self.test = TypedComponentLoader('Test Component')
-    self.extension = TypedComponentLoader('Extension Component')
-    
-  def __call__(self, portal_type, reference, version=None):
-    site = getSite()
-    return site.portal_components.loadComponent(portal_type, reference, version=version)
-
-def TypedComponentLoader(ComponentLoader):
-  """
-    A callable class which delegates component load to
-    ComponentLoader and provides default component access through
-    attributes.
-  """
-  def __init__(self, portal_type):
-    self._portal_type = portal_type
-    
-  def __call__(self, reference, version=None):
-    return ComponentLoader.__call__(self._portal_type, reference, version=version)
-
-  def __getattr__(self, key):
-    if key.startswith('_'):
-      return self.__dict__[key]
-    return self(key)
-
-component = ComponentLoader()
-
-component_revision = None
-component_dict = None
-
 class ComponentTool(BaseTool):
   """
     This tool provides methods to load the the different types 
     of components of the ERP5 framework: Document classes, interfaces,
     mixin classes, fields, accessors, etc.
   """
-
   id = "portal_components"
   meta_type = "ERP5 Component Tool"
   portal_type = "Component Tool"
 
   security = ClassSecurityInfo()
-  manage_options = BaseTool.manage_options
-
-  def loadComponent(self, portal_type, reference, version=None):
-    """
-    This first version compiles all components once. A lazy
-    version could be more efficient.
-    """
-    global component_dict
-    # Reset cache if modified
-    #if component_revision is None:
-    #  component_dict = None
-    if component_dict is None:
-      component_dict = {}
-      for document in contentValues():
-        portal_type = document.getPortalType()
-        version = document.getVersion()
-        reference = document.getReference()
-        component = document.loadComponent()
-        typed_component_dict = component_dict.setdefault(portal_type, {})
-        component_version_dict = typed_component_dict.setdefault(reference, {})
-        # How to handle default ?
-        component_version_dict[version] = component
-        component_version_dict[None] = component
-    return component_dict[portal_type][reference][version]
+  security.declareObjectProtected(Permissions.AccessContentsInformation)

product/ERP5Type/dynamic/component_class.py

+##############################################################################
+#
+# Copyright (c) 2012 Nexedi SARL and Contributors. All Rights Reserved.
+#                    Arnaud Fontaine <arnaud.fontaine@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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+##############################################################################
+
+from zLOG import LOG, INFO
+
+class ComponentProxyClass(object):
+  """
+  XXX-arnau: should maybe use Ghost class?
+  """
+  def __init__(self, component, module):
+    self._component = component
+    self._module = module
+
+    self.__isghost__ = False
+
+    # XXX-arnau: metaclass!
+    self.__class__.__name__ = component.getReference()
+    self.__class__.__module__ = component.getId().rsplit('.', 1)[0]
+    description = component.getDescription()
+    if description:
+      self.__doc__ = description
+
+  def restoreGhostState(self):
+    self.__isghost__ = True
+
+  def __getattr__(self, name):
+    if self.__isghost__:
+      self._module = self._component.load()
+      self.__isghost__ = False
+      LOG("ERP5Type.dynamic", INFO, "Reloaded %s" % self._component.getId())
+
+    return getattr(self._module, name)
+
+def generateComponentClassWrapper(namespace):
+  def generateComponentClass(component_name):
+    from Products.ERP5.ERP5Site import getSite
+    site = getSite()
+
+    component_name = '%s.%s' % (namespace, component_name)
+    try:
+      component = getattr(site.portal_components, component_name)
+    except AttributeError:
+      LOG("ERP5Type.dynamic", INFO,
+          "Could not find %s, perhaps it has not been migrated yet?" % component_name)
+
+      raise
+    else:
+      if component.getValidationState() == 'validated':
+        klass = ComponentProxyClass(component, component.load())
+        LOG("ERP5Type.dynamic", INFO, "Loaded successfully %s" % component_name)
+        return klass
+      else:
+        raise AttributeError("Component %s not validated" % component_name)
+
+  return generateComponentClass

product/ERP5Type/dynamic/dynamic_module.py

@@ -87,6 +87,8 @@ def initializeDynamicModules():
       holds accessors holders of Portal Types
     erp5.component:
       holds component modules
+    erp5.component.extension:
+      holds extension classes previously found in bt5 in instancehome/Extensions
   """
   erp5 = ModuleType("erp5")
   sys.modules["erp5"] = erp5
@@ -122,3 +124,8 @@ def initializeDynamicModules():
   # Components
   erp5.component = ModuleType("erp5.component")
   sys.modules["erp5.component"] = erp5.component
+
+  from component_class import generateComponentClassWrapper
+  erp5.component.extension = registerDynamicModule(
+    'erp5.component.extension',
+    generateComponentClassWrapper('erp5.component.extension'))