ERP5Type: Add mixin to convert ERP5 object to its JSON format

product/ERP5Type/Base.py

@@ -86,6 +86,7 @@ from Products.ERP5Type.Accessor.TypeDefinition import asDate
 from Products.ERP5Type.Message import Message
 from Products.ERP5Type.ConsistencyMessage import ConsistencyMessage
 from Products.ERP5Type.UnrestrictedMethod import UnrestrictedMethod, super_user
+from Products.ERP5Type.mixin.json_representable import JSONRepresentableMixin
 
 from zope.interface import classImplementsOnly, implementedBy
 
@@ -675,7 +676,8 @@ class Base( CopyContainer,
             ActiveObject,
             OFS.History.Historical,
             ERP5PropertyManager,
-            PropertyTranslatableBuiltInDictMixIn
+            PropertyTranslatableBuiltInDictMixIn,
+            JSONRepresentableMixin,
             ):
   """
     This is the base class for all ERP5 Zope objects.

product/ERP5Type/interfaces/json_representable.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2017 Nexedi SA and Contributors. All Rights Reserved.
+#                    Ayush Tiwari <ayush.tiwari@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 zope.interface import Interface
+
+class IJSONRepresentable(Interface):
+  """
+    An interface for objects that can be converted to JSON
+    and back to an ERP5 object.
+
+    This can be useful if we want to use JSON as much
+    as possible in ERP5 in the future and ensure
+    that certain objects (not all) can be converted to JSON
+    back and forth
+  """
+
+  def asJSON():
+    """
+      Returns a JSON representation based on
+      propertysheets and portal properties
+    """
+
+  def fromJSON():
+    """
+      Updates an object based on a JSON representation
+    """

product/ERP5Type/mixin/json_representable.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2017 Nexedi SA and Contributors. All Rights Reserved.
+#                    Ayush Tiwari <ayush.tiwari@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.
+#
+##############################################################################
+
+import json
+import xmltodict
+import zope.interface
+from OFS import XMLExportImport
+from StringIO import StringIO
+from AccessControl import ClassSecurityInfo
+from Products.ERP5Type.interfaces.json_representable import IJSONRepresentable
+from Products.ERP5Type import Permissions
+from Products.ERP5Type.Globals import InitializeClass
+
+class JSONRepresentableMixin:
+  """
+  An implementation for IJSONRepresentable
+  """
+
+  # Declarative Security
+  security = ClassSecurityInfo()
+  security.declareObjectProtected(Permissions.AccessContentsInformation)
+
+  zope.interface.implements(IJSONRepresentable)
+
+  security.declareProtected(Permissions.AccessContentsInformation, 'asJSON')
+  def asJSON(self):
+    """
+    Generate a JSON representable content for ERP5 object
+
+    Currently we use `XMLExportImport` to first convert the object to its XML
+    respresentation and then use xmltodict to convert it to dict and JSON
+    format finally
+    """
+    dict_value = self._asDict()
+    # Convert the XML to json representation
+    return json.dumps(dict_value)
+
+  def _asDict(self):
+    """
+    Gets the dict representation of the object
+    """
+    # Use OFS exportXML to first export to xml
+    f = StringIO()
+    XMLExportImport.exportXML(self._p_jar, self._p_oid, f)
+
+    # Get the value of exported XML
+    xml_value = f.getvalue()
+    return xmltodict.parse(xml_value)
+
+  security.declareProtected(Permissions.AccessContentsInformation, 'fromJSON')
+  def fromJSON(self, val):
+    """
+    Updates an object, based on a JSON representation
+    """
+    dict_value = json.loads(val)
+
+    # Convert the dict_value to XML representation
+    xml_value = xmltodict.unparse(dict_value)
+
+    f = StringIO(xml_value)
+    return XMLExportImport.importXML(self._p_jar, f)
+
+InitializeClass(JSONRepresentableMixin)