Add active_child_template to universal media player (#88816)

* Add active_children_template in universal

* handle multiple updates

* edit docstring

* Rename parameter to active_child_template

homeassistant/components/universal/media_player.py

@@ -95,6 +95,7 @@ from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
 
 ATTR_ACTIVE_CHILD = "active_child"
 
+CONF_ACTIVE_CHILD_TEMPLATE = "active_child_template"
 CONF_ATTRS = "attributes"
 CONF_CHILDREN = "children"
 CONF_COMMANDS = "commands"
@@ -128,6 +129,7 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
         vol.Optional(CONF_BROWSE_MEDIA_ENTITY): cv.string,
         vol.Optional(CONF_UNIQUE_ID): cv.string,
         vol.Optional(CONF_DEVICE_CLASS): DEVICE_CLASSES_SCHEMA,
+        vol.Optional(CONF_ACTIVE_CHILD_TEMPLATE): cv.template,
         vol.Optional(CONF_STATE_TEMPLATE): cv.template,
     },
     extra=vol.REMOVE_EXTRA,
@@ -161,6 +163,8 @@ class UniversalMediaPlayer(MediaPlayerEntity):
         self.hass = hass
         self._name = config.get(CONF_NAME)
         self._children = config.get(CONF_CHILDREN)
+        self._active_child_template = config.get(CONF_ACTIVE_CHILD_TEMPLATE)
+        self._active_child_template_result = None
         self._cmds = config.get(CONF_COMMANDS)
         self._attrs = {}
         for key, val in config.get(CONF_ATTRS).items():
@@ -186,23 +190,35 @@ class UniversalMediaPlayer(MediaPlayerEntity):
 
         @callback
         def _async_on_template_update(event, updates):
-            """Update ha state when dependencies update."""
+            """Update state when template state changes."""
-            result = updates.pop().result
+            for data in updates:
+                template = data.template
+                result = data.result
 
-            if isinstance(result, TemplateError):
+                if template == self._state_template:
-                self._state_template_result = None
+                    self._state_template_result = (
-            else:
+                        None if isinstance(result, TemplateError) else result
-                self._state_template_result = result
+                    )
+                if template == self._active_child_template:
+                    self._active_child_template_result = (
+                        None if isinstance(result, TemplateError) else result
+                    )
 
             if event:
                 self.async_set_context(event.context)
 
             self.async_schedule_update_ha_state(True)
 
-        if self._state_template is not None:
+        track_templates: list[TrackTemplate] = []
+        if self._state_template:
+            track_templates.append(TrackTemplate(self._state_template, None))
+        if self._active_child_template:
+            track_templates.append(TrackTemplate(self._active_child_template, None))
+
+        if track_templates:
             result = async_track_template_result(
                 self.hass,
-                [TrackTemplate(self._state_template, None)],
+                track_templates,
                 _async_on_template_update,
             )
             self.hass.bus.async_listen_once(
@@ -644,6 +660,9 @@ class UniversalMediaPlayer(MediaPlayerEntity):
 
     async def async_update(self) -> None:
         """Update state in HA."""
+        if self._active_child_template_result:
+            self._child_state = self.hass.states.get(self._active_child_template_result)
+            return
         self._child_state = None
         for child_name in self._children:
             if (child_state := self.hass.states.get(child_name)) and (

tests/components/universal/test_media_player.py

@@ -1278,6 +1278,56 @@ async def test_master_state_with_template(hass: HomeAssistant) -> None:
     assert events[0].context == context
 
 
+async def test_invalid_active_child_template(hass: HomeAssistant) -> None:
+    """Test invalid active child template."""
+    hass.states.async_set("media_player.mock1", STATE_PLAYING)
+    hass.states.async_set("media_player.mock2", STATE_PAUSED)
+
+    await async_setup_component(
+        hass,
+        "media_player",
+        {
+            "media_player": {
+                "platform": "universal",
+                "name": "tv",
+                "children": ["media_player.mock1", "media_player.mock2"],
+                "active_child_template": "{{invalid.invalid}}!invalid",
+            }
+        },
+    )
+    await hass.async_block_till_done()
+    await hass.async_start()
+
+    await hass.async_block_till_done()
+    assert hass.states.get("media_player.tv").state == STATE_PLAYING
+
+
+async def test_active_child_template(hass: HomeAssistant) -> None:
+    """Test override active child with template."""
+    hass.states.async_set("media_player.mock1", STATE_PLAYING)
+    hass.states.async_set("media_player.mock2", STATE_PAUSED)
+
+    await async_setup_component(
+        hass,
+        "media_player",
+        {
+            "media_player": {
+                "platform": "universal",
+                "name": "tv",
+                "children": ["media_player.mock1", "media_player.mock2"],
+                "active_child_template": "{{ 'media_player.mock2' }}",
+            }
+        },
+    )
+    await hass.async_block_till_done()
+    await hass.async_start()
+
+    hass.states.async_set("media_player.mock2", STATE_ON)
+
+    await hass.async_block_till_done()
+    assert hass.states.get("media_player.tv").state == STATE_ON
+
+
 async def test_reload(hass: HomeAssistant) -> None:
     """Test reloading the media player from yaml."""
     hass.states.async_set("input_boolean.test", STATE_OFF)