Create the unique_id in the template (vs. model)

umap/models.py

@@ -194,10 +194,6 @@ class Map(NamedModel):
     objects = models.Manager()
     public = PublicManager()
 
-    @property
-    def unique_id(self):
-        return f"map_{self.pk}"
-
     @property
     def preview_settings(self):
         from .views import _urls_for_js

umap/templates/umap/map_table.html

@@ -13,14 +13,15 @@
   {% endif %}
   <tbody>
     {% for map_inst in maps %}
-      {{ map_inst.preview_settings|json_script:map_inst.unique_id }}
+      {% with unique_id="map_"|addstr:map_inst.pk %}
+        {{ map_inst.preview_settings|json_script:unique_id }}
         <tr>
           <td>
             <a href="{{ map_inst.get_absolute_url }}">{{ map_inst.name }}</a>
-          <button class="map-opener" data-map-id="{{ map_inst.unique_id }}">{% blocktrans %}Preview{% endblocktrans %}</button>
+            <button class="map-opener" data-map-id="{{ unique_id }}">{% blocktrans %}Preview{% endblocktrans %}</button>
             <dialog>
               <form method="dialog">
-              <div id="{{ map_inst.unique_id }}_target" class="map_fragment"></div>
+                <div id="{{ unique_id }}_target" class="map_fragment"></div>
                 <p class="close-dialog">
                   <button type="submit">Close</button>
                 </p>
@@ -38,6 +39,7 @@
             <a href="{% url 'map_download' map_inst.pk %}">{% translate "Download" %}</a>
           </td>
         </tr>
+      {% endwith %}
     {% endfor %}
   </tbody>
 </table>

umap/templatetags/umap_tags.py

@@ -60,3 +60,9 @@ def ipdb(what):
 
     ipdb.set_trace()
     return ""
+
+
+@register.filter
+def addstr(arg1, arg2):
+    # Necessity: https://stackoverflow.com/a/23783666
+    return str(arg1) + str(arg2)