Added get_comment overridable method to TaskState

wagtail/admin/templates/wagtailadmin/pages/workflow_history/detail.html

@@ -83,6 +83,8 @@
                                 {% else %}
                                     <div class="status-tag primary">{{ task_state.get_status_display }}</div>
                                 {% endif %}
+
+                                <p>{{ task_state.specific.get_comment }}</p>
                             </td>
                         {% endfor %}
                     </tr>
@@ -126,6 +128,8 @@
                                 {% else %}
                                     <div class="status-tag primary">{{ timeline_item.task_state.get_status_display }}</div>
                                 {% endif %}
+
+                                <p>{{ task_state.specific.get_comment }}</p>
                             {% endif %}
                         </td>
                     </tr>

wagtail/core/models.py

@@ -3066,6 +3066,15 @@ class TaskState(MultiTableCopyMixin, models.Model):
         instance.save()
         return instance
 
+    def get_comment(self):
+        """
+        Returns a string that is displayed in workflow history.
+
+        This could be a comment by the reviewer, or generated.
+        Use mark_safe to return HTML.
+        """
+        return ""
+
     class Meta:
         verbose_name = _('Task state')
         verbose_name_plural = _('Task states')