Merge pull request #3094 from differentreality/2738_history_changes_deleted_models

Fix version history for deleted models

app/views/shared/_object_changes.html.haml

@@ -21,6 +21,20 @@
           %th Action
     %tbody
       - if version.event != 'destroy'
+        -# For deleted models we cannot use all of PaperTrail functionalities, so we simplify the output
+        - if version.item_type == 'Campaign' || version.item_type == 'Target' || version.item_type == 'EventAttachment'
+          - changeset = version.object_changes.split("\n")
+          -# object_changes field is now in the format of ["---", "id:", "- ", "- 6", "conference_id:",  "- ",  "- 2"]
+          - changeset.shift
+          - changeset.each_slice(3).each do |attribute_changes|
+            %tr
+              -# Remove the dash at the beginning
+              - attribute_changes.map!{ |x| x.sub(/^- /, '') }
+              %td= attribute_changes[0]
+              - if version.event != 'create'
+                %td= attribute_changes[1]
+              %td= attribute_changes[2]
+        - else
           - version.changeset.reject{ |_, values| values[0].blank? && values[1].blank? }.each do |attribute, values|
             %tr
               %td= attribute