Question

I’m trying to find out who is the user who last changed a document.
Preferably, I would like to make collections based on this info…
All I can find is the Modification Date…

Using the script from this link, I do not seem to find the information on the last user in the metadata.

Is this correct( no modifying user info…), and if so, can it be done?

Answer 1

As @MikkoOhtamaa wrote, Plone doesn’t save the last modifier on object by default. But Plone does have version control enabled by default for Pages, News Items, Events and Link (by CMFEditions) and version metadata has the information of the latest modifier.

If it’s OK to read the information from the version metadata and limit the feature only for version controlled content types, I think, you’d need to

1. Register a new index (using catalog.xml in your add-on’s Generic Setup -profile; you may also want to register a metadata column to get the indexed data be returned in results):

   <?xml version="1.0"?>
   <object name="portal_catalog" meta_type="Plone Catalog Tool">
     <index name="last_modifier" meta_type="FieldIndex">
       <indexed_attr value="last_modifier"/>
     </index>
     <column value="last_modifier"/>
   </object>
   

2. Register a custom search condition to be used in Topic-collections (using portal_atct.xml in your add-on’s Generic Setup -profile) and a metadata column to get the information listed on its tabular view:

   <?xml version="1.0"?>
   <atcttool>
     <topic_indexes>
       <index name="last_modifier"
             description="The last user, who has modified the object"
             friendlyName="Last Modifier"
             enabled="True">
         <criteria>ATCurrentAuthorCriterion</criteria>
         <criteria>ATListCriterion</criteria>
         <criteria>ATSimpleStringCriterion</criteria>
       </index>
     </topic_indexes>
     <topic_metadata>
       <metadata name="last_modifier"
                 description="The last user, who has modified the object"
                 friendlyName="Last Modifier"
                 enabled="True"/>
     </topic_metadata>
   </atcttool>
   

3. Write a custom indexer, which looks up the last modifier from the version metadata and indexes it:

   # -*- coding: utf-8 -*-
   """Last modifier indexer"""
   
   from zope.component import getUtility
   
   from plone.indexer import indexer
   
   from Products.CMFCore.interfaces import ISiteRoot, IContentish
   from Products.CMFCore.utils import getToolByName
   
   
   @indexer(IContentish)
   def indexLastModifier(context):
       try:
           creator = context.Creators()[0]  # fallback value
       except AttributeError:
           creator = None
       except IndexError:
           creator = None
   
       site = getUtility(ISiteRoot)
       rt = getToolByName(site, "portal_repository")
   
       if rt is None or not rt.isVersionable(context):
           # not versionable; fallback to the creator
           return creator
   
       history = rt.getHistoryMetadata(context)
           if not history:
           # empty history; fallback to the creator
           return creator
   
       if not rt.isUpToDate(context):
           # history not up-to-date; fallback to the authenticated user
           mtool = getToolByName(site, "portal_membership")
           if mtool.isAnonymousUser():
               # no authenticated user found; fallback to the creator
               return creator
           else:
               return mtool.getAuthenticatedMember().getId()
   
       length = history.getLength(countPurged=False)
   
       last = history.retrieve(length - 1)
       if not last or type(last) != dict:
           # unexpected version metadata; fallback to the creator
           return creator
   
       metadata = last.get("metadata")
       if not metadata or type(metadata) != dict:
           # unexpected version metadata; fallback to the creator
           return creator
   
       sys_metadata = metadata.get("sys_metadata")
       if not sys_metadata or type(sys_metadata) != dict:
           # unexpected version metadata; fallback to the creator
           return creator
   
       principal = sys_metadata.get("principal")
       if not principal or type(principal) != str:
           # unexpected version metadata; fallback to the creator
           return creator
   
       return principal
   

4. And register the indexer in your add-on’s configure.zcml:

   <adapter name="last_modifier"
            factory=".indexers.indexLastModifier" />
   

Be aware, though, that because the version control mechanism is triggered by the same events as catalog indexer, we may not be sure that the metadata for the most recent version exists when we are called to index it. Above, I apply dummy heuristics that when the repository says that the version history metadata is outdated when compared to the object to be indexed, I index the username of the current user instead (and expect that user been just editing the document).