fixed a bug in the html formatting (no return statement)

doi_classes.py

@@ -78,7 +78,7 @@ class DateTimeRange:
   def djson(self): return {'date': f'{self.sdate.value.strftime(self.sdate.ISO8601)}/{self.edate.value.strftime(self.edate.ISO8601) if self.edate is not None else ""}', 'dateType': self.role}
   @property
   def html_paragraph(self): 
-    if self.edate is None: jinja2.Template("""<p>{{item.role}}: {{item.sdate.value.strftime(item.sdate.ISO8601)}}/</p>""").render(item=self)
+    if self.edate is None: return jinja2.Template("""<p>{{item.role}}: {{item.sdate.value.strftime(item.sdate.ISO8601)}}/</p>""").render(item=self)
     return jinja2.Template("""<p>{{item.role}}: {{item.sdate.value.strftime(item.sdate.ISO8601)}}/{{item.edate.value.strftime(item.edate.ISO8601)}}</p>""").render(item=self)
 
 class GEOMSDateTimeFactory: