[erp5_core]: DiffTool, do not break projects not having yet deepdiff and unidiff installed

product/ERP5/bootstrap/erp5_core/DocumentTemplateItem/portal_components/document.erp5.DiffTool.py

@@ -27,10 +27,20 @@
 #
 ##############################################################################
 
-import deepdiff
 import difflib
-from deepdiff import DeepDiff
-from unidiff import PatchSet
+import warnings
+try:
+  import deepdiff
+except ImportError:
+  deepdiff = None
+  warnings.warn("Please install deepdiff, it is needed by Diff Tool",
+                DeprecationWarning)
+try:
+  from unidiff import PatchSet
+except ImportError:
+  PatchSet = None
+  warnings.warn("Please install unidiff, it is needed by Diff Tool",
+                DeprecationWarning)
 from AccessControl import ClassSecurityInfo
 from Products.ERP5Type import Permissions
 from Products.ERP5Type.Globals import InitializeClass
@@ -124,7 +134,7 @@ class PortalPatch:
     new_value_dict = self.removePropertyList(self.new_value, export=True)
 
     # Get the DeepDiff in tree format.
-    tree_diff = DeepDiff(old_value_dict,
+    tree_diff = deepdiff.DeepDiff(old_value_dict,
                          new_value_dict,
                          view='tree')
     diff_tree_list = []