Enable codemirror diff view for web pages

ERP5's Code mirror supports viewing history of editions using codemirror's merge mode ( http://codemirror.net/demo/merge.html ).

This was enabled for portal_components, but not for web pages.

This moves the methods used by the components in a mixin class and make `TextDocument` class use this mixin.

This way, we can benefit from diff view on web pages as well:

![ERP5-history-on-web-pages](/uploads/2bd381948266da46225ae26fd807bd51/ERP5-history-on-web-pages.png)

@romain @vincentB @katomaso unless this interfere with your work of making codemirror works in renderjs ui, I think we can enable this. It does not include any change to codemirror code, just enable everywhere what was available only on components.

@klaus I did not check, but we probably want this enabled for PyData Script as well.

/reviewed-on !449

product/ERP5/Document/TextDocument.py

@@ -42,6 +42,7 @@ from string import Template
 # Mixin Import
 from Products.ERP5.mixin.cached_convertable import CachedConvertableMixin
 from Products.ERP5.mixin.base_convertable import BaseConvertableFileMixin
+from Products.ERP5Type.mixin.text_content_history import TextContentHistoryMixin
 from Products.ERP5Type.Utils import guessEncodingFromText
 
 from lxml import html as etree_html
@@ -49,7 +50,7 @@ from lxml import etree
 
 from Products.ERP5Type.ImageUtil import transformUrlToDataURI
 
-class TextDocument(CachedConvertableMixin, BaseConvertableFileMixin,
+class TextDocument(CachedConvertableMixin, BaseConvertableFileMixin, TextContentHistoryMixin,
                                                             TextContent, File):
     """A TextDocument impletents IDocument, IFile, IBaseConvertable, ICachedconvertable
     and ITextConvertable

product/ERP5Type/Core/DocumentComponent.py

@@ -28,13 +28,14 @@
 ##############################################################################
 
 from Products.ERP5Type.mixin.component import ComponentMixin
+from Products.ERP5Type.mixin.text_content_history import TextContentHistoryMixin
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions
 
 import zope.interface
 from Products.ERP5Type.interfaces.component import IComponent
 
-class DocumentComponent(ComponentMixin):
+class DocumentComponent(ComponentMixin, TextContentHistoryMixin):
   """
   ZODB Component for Documents in bt5 only for now (which used to be installed
   in INSTANCE_HOME/Document) but this will also be used later on for Documents

product/ERP5Type/Core/ExtensionComponent.py

@@ -28,13 +28,14 @@
 ##############################################################################
 
 from Products.ERP5Type.mixin.component import ComponentMixin
+from Products.ERP5Type.mixin.text_content_history import TextContentHistoryMixin
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions
 
 import zope.interface
 from Products.ERP5Type.interfaces.component import IComponent
 
-class ExtensionComponent(ComponentMixin):
+class ExtensionComponent(ComponentMixin, TextContentHistoryMixin):
   """
   ZODB Component for Extensions previously defined in the bt5 and installed in
   INSTANCE_HOME/Extensions

product/ERP5Type/Core/TestComponent.py

@@ -28,13 +28,14 @@
 ##############################################################################
 
 from Products.ERP5Type.mixin.component import ComponentMixin
+from Products.ERP5Type.mixin.text_content_history import TextContentHistoryMixin
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions
 
 import zope.interface
 from Products.ERP5Type.interfaces.component import IComponent
 
-class TestComponent(ComponentMixin):
+class TestComponent(ComponentMixin, TextContentHistoryMixin):
   """
   ZODB Component for Live Tests only (previously defined in the bt5 and
   installed in INSTANCE_HOME/tests) as other kind of Tests should be

product/ERP5Type/mixin/component.py

@@ -385,48 +385,4 @@ class ComponentMixin(PropertyRecordableMixin, Base):
 
     return new_component
 
-  security.declareProtected(Permissions.ModifyPortalContent,
-                            'getTextContentHistoryRevisionDictList')
-  def getTextContentHistoryRevisionDictList(self, limit=100):
-    """
-    TODO
-    """
-    history_dict_list = self._p_jar.db().history(self._p_oid, size=limit)
-    if history_dict_list is None:
-      # Storage doesn't support history
-      return ()
-
-    from struct import unpack
-    from OFS.History import historicalRevision
-
-    previous_text_content = None
-    result = []
-    for history_dict in history_dict_list:
-      text_content = historicalRevision(self, history_dict['tid']).getTextContent()
-      if text_content and text_content != previous_text_content:
-        history_dict['time'] = history_dict['time']
-        history_dict['user_name'] = history_dict['user_name'].strip()
-        history_dict['key'] = '.'.join(map(str, unpack(">HHHH", history_dict['tid'])))
-        del history_dict['tid']
-        del history_dict['size']
-
-        result.append(history_dict)
-        previous_text_content = text_content
-
-    return result
-
-  security.declareProtected(Permissions.ModifyPortalContent,
-                            'getTextContentHistory')
-  def getTextContentHistory(self, key):
-    """
-    TODO
-    """
-    from struct import pack
-    from OFS.History import historicalRevision
-
-    serial = apply(pack, ('>HHHH',) + tuple(map(int, key.split('.'))))
-    rev = historicalRevision(self, serial)
-
-    return rev.getTextContent()
-
 InitializeClass(ComponentMixin)

product/ERP5Type/mixin/text_content_history.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2017 Nexedi SA and Contributors. All Rights Reserved.
+#
+# 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 AccessControl import ClassSecurityInfo
+from Products.ERP5Type.Globals import InitializeClass
+from Products.ERP5Type import Permissions
+
+
+class TextContentHistoryMixin:
+  """Mixin that provides access to history of edit of the text content property.
+
+  To be used with erp5_code_mirror
+  """
+  security = ClassSecurityInfo()
+
+  security.declareProtected(Permissions.ModifyPortalContent,
+                            'getTextContentHistoryRevisionDictList')
+  def getTextContentHistoryRevisionDictList(self, limit=100):
+    """Returns the history of edition as a list of dictionnaries.
+    """
+    history_dict_list = self._p_jar.db().history(self._p_oid, size=limit)
+    if history_dict_list is None:
+      # Storage doesn't support history
+      return ()
+
+    from struct import unpack
+    from OFS.History import historicalRevision
+
+    previous_text_content = None
+    result = []
+    for history_dict in history_dict_list:
+      text_content = historicalRevision(self, history_dict['tid'])._baseGetTextContent()
+      if text_content and text_content != previous_text_content:
+        history_dict['time'] = history_dict['time']
+        history_dict['user_name'] = history_dict['user_name'].strip()
+        history_dict['key'] = '.'.join(map(str, unpack(">HHHH", history_dict['tid'])))
+        del history_dict['tid']
+        del history_dict['size']
+
+        result.append(history_dict)
+        previous_text_content = text_content
+
+    return result
+
+  security.declareProtected(Permissions.ModifyPortalContent,
+                            'getTextContentHistory')
+  def getTextContentHistory(self, key):
+    """Returns the text content of a previous version of the document.
+    """
+    from struct import pack
+    from OFS.History import historicalRevision
+
+    serial = apply(pack, ('>HHHH',) + tuple(map(int, key.split('.'))))
+    rev = historicalRevision(self, serial)
+
+    return rev._baseGetTextContent()
+
+InitializeClass(TextContentHistoryMixin)