Defer template tracking setup until template entity start (#40388)

homeassistant/components/template/template_entity.py

@@ -213,7 +213,6 @@ class TemplateEntity(Entity):
         attribute = _TemplateAttribute(
             self, attribute, template, validator, on_update, none_on_template_error
         )
-        attribute.async_setup()
         self._template_attrs.setdefault(template, [])
         self._template_attrs[template].append(attribute)
 
@@ -252,22 +251,21 @@ class TemplateEntity(Entity):
                     event, update.template, update.last_result, update.result
                 )
 
-        if self._async_update:
-            self.async_write_ha_state()
+        self.async_write_ha_state()
 
     async def _async_template_startup(self, *_) -> None:
-        # _handle_results will not write state until "_async_update" is set
-        template_var_tups = [
-            TrackTemplate(template, None) for template in self._template_attrs
-        ]
+        template_var_tups = []
+        for template, attributes in self._template_attrs.items():
+            template_var_tups.append(TrackTemplate(template, None))
+            for attribute in attributes:
+                attribute.async_setup()
 
         result_info = async_track_template_result(
             self.hass, template_var_tups, self._handle_results
         )
         self.async_on_remove(result_info.async_remove)
-        result_info.async_refresh()
-        self.async_write_ha_state()
         self._async_update = result_info.async_refresh
+        result_info.async_refresh()
 
     async def async_added_to_hass(self) -> None:
         """Run when entity about to be added to hass."""