Add template support to service targets (#46977)

Co-authored-by: Paulus Schoutsen <balloob@gmail.com>

homeassistant/helpers/config_validation.py

@@ -847,11 +847,18 @@ PLATFORM_SCHEMA = vol.Schema(
 PLATFORM_SCHEMA_BASE = PLATFORM_SCHEMA.extend({}, extra=vol.ALLOW_EXTRA)
 
 ENTITY_SERVICE_FIELDS = {
-    vol.Optional(ATTR_ENTITY_ID): comp_entity_ids,
-    vol.Optional(ATTR_DEVICE_ID): vol.Any(
-        ENTITY_MATCH_NONE, vol.All(ensure_list, [str])
+    # Either accept static entity IDs, a single dynamic template or a mixed list
+    # of static and dynamic templates. While this could be solved with a single
+    # complex template, handling it like this, keeps config validation useful.
+    vol.Optional(ATTR_ENTITY_ID): vol.Any(
+        comp_entity_ids, dynamic_template, vol.All(list, template_complex)
+    ),
+    vol.Optional(ATTR_DEVICE_ID): vol.Any(
+        ENTITY_MATCH_NONE, vol.All(ensure_list, [vol.Any(dynamic_template, str)])
+    ),
+    vol.Optional(ATTR_AREA_ID): vol.Any(
+        ENTITY_MATCH_NONE, vol.All(ensure_list, [vol.Any(dynamic_template, str)])
     ),
-    vol.Optional(ATTR_AREA_ID): vol.Any(ENTITY_MATCH_NONE, vol.All(ensure_list, [str])),
 }
 
 

homeassistant/helpers/service.py

@@ -28,6 +28,7 @@ from homeassistant.const import (
     ATTR_AREA_ID,
     ATTR_DEVICE_ID,
     ATTR_ENTITY_ID,
+    CONF_ENTITY_ID,
     CONF_SERVICE,
     CONF_SERVICE_DATA,
     CONF_SERVICE_TEMPLATE,
@@ -189,7 +190,22 @@ def async_prepare_call_from_config(
 
     domain, service = domain_service.split(".", 1)
 
-    target = config.get(CONF_TARGET)
+    target = {}
+    if CONF_TARGET in config:
+        conf = config.get(CONF_TARGET)
+        try:
+            template.attach(hass, conf)
+            target.update(template.render_complex(conf, variables))
+            if CONF_ENTITY_ID in target:
+                target[CONF_ENTITY_ID] = cv.comp_entity_ids(target[CONF_ENTITY_ID])
+        except TemplateError as ex:
+            raise HomeAssistantError(
+                f"Error rendering service target template: {ex}"
+            ) from ex
+        except vol.Invalid as ex:
+            raise HomeAssistantError(
+                f"Template rendered invalid entity IDs: {target[CONF_ENTITY_ID]}"
+            ) from ex
 
     service_data = {}
 

tests/helpers/test_service.py

@@ -195,6 +195,24 @@ class TestServiceHelpers(unittest.TestCase):
             "area_id": ["test-area-id"],
         }
 
+        config = {
+            "service": "{{ 'test_domain.test_service' }}",
+            "target": {
+                "area_id": ["area-42", "{{ 'area-51' }}"],
+                "device_id": ["abcdef", "{{ 'fedcba' }}"],
+                "entity_id": ["light.static", "{{ 'light.dynamic' }}"],
+            },
+        }
+
+        service.call_from_config(self.hass, config)
+        self.hass.block_till_done()
+
+        assert dict(self.calls[1].data) == {
+            "area_id": ["area-42", "area-51"],
+            "device_id": ["abcdef", "fedcba"],
+            "entity_id": ["light.static", "light.dynamic"],
+        }
+
     def test_service_template_service_call(self):
         """Test legacy service_template call with templating."""
         config = {