Refactor Publication Workflow

+ Fixes issue with publication date being updates on all approvals
+ Adds column to Dataset History admin that lists the metadata changes.

Issue #348

archive_api/admin.py

@@ -9,11 +9,36 @@
 from django.shortcuts import redirect, render
 from django.urls import path
 from django.utils.datetime_safe import datetime
+from django.utils.safestring import mark_safe
 
 from archive_api.models import DataSet, DataSetDownloadLog, MeasurementVariable, Person, Plot, Site
 from simple_history.admin import SimpleHistoryAdmin
 
-admin.site.register(DataSet,SimpleHistoryAdmin)
+
+@admin.register(DataSet)
+class DataSetHistoryAdmin(SimpleHistoryAdmin):
+    list_display = ["data_set_id", "version", "status", "name"]
+    history_list_display = ["list_changes"]
+    search_fields = ['name', 'status', "ngt_id", "version"]
+
+    def list_changes(self, obj):
+        """
+        Lists the changes between revisions in the Admin UI
+
+        See: https://django-simple-history.readthedocs.io/en/latest/history_diffing.html
+
+
+        :param obj:
+        :return:
+        """
+        diff = []
+        if obj.prev_record:
+            delta = obj.diff_against(obj.prev_record)
+            for change in delta.changes:
+                diff.append("<b>- {}:</b> changed from `{}` to `{}`".format(change.field, change.old, change.new))
+
+        # Mark safe (https://docs.djangoproject.com/en/4.0/ref/utils/#django.utils.safestring.mark_safe)
+        return mark_safe("\n<br>".join(diff))
 
 
 class CsvImportForm(forms.Form):

archive_api/viewsets.py

@@ -278,7 +278,7 @@ def change_status(self, request, status):
                         dataset.archive.name = "{}/{}".format(new_path, filename)
                 elif status == APPROVED:
                     dataset.approval_date = now
-                    if original_status == SUBMITTED:
+                    if original_status == SUBMITTED and not dataset.publication_date:
                         # The dataset is NOT LIVE yet and is being approved for the first time
                         dataset.publication_date = now
                         dataset.status = status