165 templating content for all types (#170)

Submitting as an initial draft in order to guage feedback on the style.
In particular the solution to adding the code to the `toggle` menu item,
which has incurred duplication of code as I can't inherit from two
classes.

HISTORY.md

@@ -31,3 +31,4 @@
 |   2.16  | Bug fix for lack of phone connection when starting the application. Includes new activity reporting features from [KPWhiver](https://github.com/KPWhiver) covering steps, heart rate, floors climbed and descended, and respiration rate. |
 |   2.17  | Bug fix for reporting activity metrics that are not found on some devices. |
 |   2.18  | Bug fix for reporting activity metrics that might be `null` sometimes. This is unsimulatable situation, so this version is a change based on an informed guess. |
+|   2.19  | A template to evaluate is now optionally allowed on both `group` and `toggle` menu items. The template to evaluate is non-optional on a `template` menu item. |

config.schema.json

@@ -22,14 +22,16 @@
           "$ref": "#/$defs/entity"
         },
         "name": {
-          "title": "Your familiar name",
+          "$ref": "#/$defs/name"
-          "type": "string"
         },
         "type": {
-          "title": "Menu item type",
+          "$ref": "#/$defs/type",
-          "description": "One of 'tap', 'template', 'toggle' or 'group'.",
           "const": "toggle"
         },
+        "content": {
+          "$ref": "#/$defs/content",
+          "description": "Optional in a toggle."
+        },
         "tap_action": {
           "type": "object",
           "properties": {
@@ -55,16 +57,13 @@
               "description": "Use 'tap_action' instead to mirror Home Assistant."
             },
             "name": {
-              "title": "Your familiar name",
+              "$ref": "#/$defs/name"
-              "type": "string"
             },
             "content": {
-              "title": "What to display (template)",
+              "$ref": "#/$defs/content"
-              "type": "string"
             },
             "type": {
-              "title": "Menu item type",
+              "$ref": "#/$defs/type",
-              "description": "One of 'tap', 'template', 'toggle' or 'group'.",
               "const": "template"
             }
           },
@@ -78,16 +77,13 @@
               "$ref": "#/$defs/entity"
             },
             "name": {
-              "title": "Your familiar name",
+              "$ref": "#/$defs/name"
-              "type": "string"
             },
             "content": {
-              "title": "What to display (template)",
+              "$ref": "#/$defs/content"
-              "type": "string"
             },
             "type": {
-              "title": "Menu item type",
+              "$ref": "#/$defs/type",
-              "description": "One of 'tap', 'template', 'toggle' or 'group'.",
               "const": "template"
             },
             "tap_action": {
@@ -106,12 +102,10 @@
           "$ref": "#/$defs/entity"
         },
         "name": {
-          "title": "Your familiar name",
+          "$ref": "#/$defs/name"
-          "type": "string"
         },
         "type": {
-          "title": "Menu item type",
+          "$ref": "#/$defs/type",
-          "description": "One of 'tap', 'template', 'toggle' or 'group'.",
           "const": "tap"
         },
         "service": {
@@ -153,10 +147,13 @@
           "type": "string"
         },
         "type": {
-          "title": "Menu item type",
+          "$ref": "#/$defs/type",
-          "description": "One of 'tap', 'template', 'toggle' or 'group'.",
           "const": "group"
         },
+        "content": {
+          "$ref": "#/$defs/content",
+          "description": "Optional in a group."
+        },
         "items": {
           "$ref": "#/$defs/items"
         }
@@ -164,6 +161,10 @@
       "required": ["name", "title", "type", "items"],
       "additionalProperties": false
     },
+    "type": {
+      "title": "Menu item type",
+      "description": "One of 'tap', 'template', 'toggle' or 'group'."
+    },
     "items": {
       "type": "array",
       "maxItems": 16,
@@ -184,6 +185,10 @@
         ]
       }
     },
+    "name": {
+      "title": "Your familiar name",
+      "type": "string"
+    },
     "entity": {
       "type": "string",
       "title": "Home Assistant entity name",
@@ -213,6 +218,10 @@
       },
       "required": ["service"]
     },
+    "content": {
+      "title": "Jinja2 template defining the text to display.",
+      "type": "string"
+    },
     "confirm": {
       "type": "boolean",
       "default": false,

examples/Templates.md

@@ -10,6 +10,9 @@ In order to provide the most functionality possible the content of the menu item
   - `{{` ... `}}` for Expressions to print to the template output
   - `{#` ... `#}` for Comments not included in the template output
 
+> [!IMPORTANT]
+> In order to avoid "Template Error" being displayed as the return value, make sure your Jinja2 template returns a `string`, not a number of some variety. _All numbers must be formatted to strings_ so the application does not need to distinguish an `integer` from a `float`.
+
 ## States
 
 In this example we get the battery level of the device and add the percent sign. *Very simple*

source/HomeAssistantApp.mc

@@ -429,12 +429,11 @@ class HomeAssistantApp extends Application.AppBase {
     // We need to spread out the API calls so as not to overload the results queue and cause Communications.BLE_QUEUE_FULL
     // (-101) error. This function is called by a timer every Globals.menuItemUpdateInterval ms.
     function updateNextMenuItemInternal() as Void {
-        var itu = mItemsToUpdate as Lang.Array<HomeAssistantToggleMenuItem>;
+        if (mItemsToUpdate != null) {
-        if (itu != null) {
             // System.println("HomeAssistantApp updateNextMenuItemInternal(): Doing update for item " + mNextItemToUpdate + ", mIsInitUpdateCompl=" + mIsInitUpdateCompl);
-            itu[mNextItemToUpdate].getState();
+            mItemsToUpdate[mNextItemToUpdate].getState();
-            // mNextItemToUpdate = (mNextItemToUpdate + 1) % itu.size() - But with roll-over detection
+            // mNextItemToUpdate = (mNextItemToUpdate + 1) % mItemsToUpdate.size() - But with roll-over detection
-            if (mNextItemToUpdate == itu.size()-1) {
+            if (mNextItemToUpdate == mItemsToUpdate.size()-1) {
                 // Last item completed return to the start of the list
                 mNextItemToUpdate  = 0;
                 mIsInitUpdateCompl = true;

source/HomeAssistantGroupMenuItem.mc

@@ -14,27 +14,31 @@
 //
 // Description:
 //
-// Menu button with an icon that opens a sub-menu, i.e. group.
+// Menu button with an icon that opens a sub-menu, i.e. group, and optionally renders
+// a Home Assistant Template.
 //
 //-----------------------------------------------------------------------------------
 
 using Toybox.Lang;
 using Toybox.WatchUi;
 
-class HomeAssistantGroupMenuItem extends WatchUi.IconMenuItem {
+class HomeAssistantGroupMenuItem extends TemplateMenuItem {
     private var mMenu as HomeAssistantView;
 
     function initialize(
         definition as Lang.Dictionary,
+        template   as Lang.String,
         icon       as WatchUi.Drawable,
         options    as {
             :alignment as WatchUi.MenuItem.Alignment
-        } or Null) {
+        } or Null
+    ) {
 
-        WatchUi.IconMenuItem.initialize(
+        TemplateMenuItem.initialize(
             definition.get("name") as Lang.String,
-            null,
+            template,
-            null,
+            // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
+            getApp().method(:updateNextMenuItem),
             icon,
             options
         );

source/HomeAssistantMenuItemFactory.mc

@@ -67,10 +67,12 @@ class HomeAssistantMenuItemFactory {
     function toggle(
         label     as Lang.String or Lang.Symbol,
         entity_id as Lang.String or Null,
+        template  as Lang.String or Null,
         confirm   as Lang.Boolean
     ) as WatchUi.MenuItem {
         return new HomeAssistantToggleMenuItem(
             label,
+            template,
             confirm,
             { "entity_id" => entity_id },
             mMenuItemOptions
@@ -145,7 +147,15 @@ class HomeAssistantMenuItemFactory {
         );
     }
 
-    function group(definition as Lang.Dictionary) as WatchUi.MenuItem {
+    function group(
-        return new HomeAssistantGroupMenuItem(definition, mGroupTypeIcon, mMenuItemOptions);
+        definition as Lang.Dictionary,
+        template   as Lang.String or Null
+    ) as WatchUi.MenuItem {
+        return new HomeAssistantGroupMenuItem(
+            definition,
+            template,
+            mGroupTypeIcon,
+            mMenuItemOptions
+        );
     }
 }

source/HomeAssistantTemplateMenuItem.mc

@@ -26,9 +26,8 @@ using Toybox.Lang;
 using Toybox.WatchUi;
 using Toybox.Graphics;
 
-class HomeAssistantTemplateMenuItem extends WatchUi.IconMenuItem {
+class HomeAssistantTemplateMenuItem extends TemplateMenuItem {
     private var mHomeAssistantService as HomeAssistantService;
-    private var mTemplate             as Lang.String;
     private var mService              as Lang.String or Null;
     private var mConfirm              as Lang.Boolean;
     private var mData                 as Lang.Dictionary or Null;
@@ -45,16 +44,16 @@ class HomeAssistantTemplateMenuItem extends WatchUi.IconMenuItem {
         } or Null,
         haService as HomeAssistantService
     ) {
-        WatchUi.IconMenuItem.initialize(
+        TemplateMenuItem.initialize(
             label,
-            null,
+            template,
-            null,
+            // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
+            getApp().method(:updateNextMenuItem),
             icon,
             options
         );
 
         mHomeAssistantService = haService;
-        mTemplate             = template;
         mService              = service;
         mConfirm              = confirm;
         mData                 = data;
@@ -79,116 +78,4 @@ class HomeAssistantTemplateMenuItem extends WatchUi.IconMenuItem {
         }
     }
 
-    // Callback function after completing the GET request to fetch the status.
-    // Terminate updating the toggle menu items via the chain of calls for a permanent network
-    // error. The ErrorView cancellation will resume the call chain.
-    //
-    function onReturnGetState(responseCode as Lang.Number, data as Null or Lang.Dictionary) as Void {
-        // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: " + responseCode);
-        // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Data: " + data);
-
-        var status = WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String;
-        switch (responseCode) {
-            case Communications.BLE_HOST_TIMEOUT:
-            case Communications.BLE_CONNECTION_UNAVAILABLE:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: BLE_HOST_TIMEOUT or BLE_CONNECTION_UNAVAILABLE, Bluetooth connection severed.");
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoPhone) as Lang.String + ".");
-                break;
-
-            case Communications.BLE_QUEUE_FULL:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: BLE_QUEUE_FULL, API calls too rapid.");
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.ApiFlood) as Lang.String);
-                break;
-
-            case Communications.NETWORK_REQUEST_TIMED_OUT:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: NETWORK_REQUEST_TIMED_OUT, check Internet connection.");
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoResponse) as Lang.String);
-                break;
-
-            case Communications.INVALID_HTTP_BODY_IN_NETWORK_RESPONSE:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: INVALID_HTTP_BODY_IN_NETWORK_RESPONSE, check JSON is returned.");
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoJson) as Lang.String);
-                break;
-
-            case Communications.NETWORK_RESPONSE_OUT_OF_MEMORY:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: NETWORK_RESPONSE_OUT_OF_MEMORY, are we going too fast?");
-                var myTimer = new Timer.Timer();
-                // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
-                myTimer.start(getApp().method(:updateNextMenuItem), Globals.scApiBackoff, false);
-                // Revert status
-                status = getApp().getApiStatus();
-                break;
-
-            case 404:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: 404, page not found. Check API URL setting.");
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.ApiUrlNotFound) as Lang.String);
-                break;
-
-            case 400:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: 400, bad request. Template error.");
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.TemplateError) as Lang.String);
-                break;
-
-            case 200:
-                status = WatchUi.loadResource($.Rez.Strings.Available) as Lang.String;
-                var label = data.get("request");
-                if (label == null) {
-                    setSubLabel($.Rez.Strings.Empty);
-                } else if(label instanceof Lang.String) {
-                    setSubLabel(label);
-                } else if(label instanceof Lang.Dictionary) {
-                    // System.println("HomeAssistantTemplateMenuItem onReturnGetState() label = " + label);
-                    if (label.get("error") != null) {
-                        setSubLabel($.Rez.Strings.TemplateError);
-                    } else {
-                        setSubLabel($.Rez.Strings.PotentialError);
-                    }
-                }
-                requestUpdate();
-                // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
-                getApp().updateNextMenuItem();
-                break;
-
-            default:
-                // System.println("HomeAssistantTemplateMenuItem onReturnGetState(): Unhandled HTTP response code = " + responseCode);
-                ErrorView.show(WatchUi.loadResource($.Rez.Strings.UnhandledHttpErr) as Lang.String + responseCode);
-        }
-        getApp().setApiStatus(status);
-    }
-
-    function getState() as Void {
-        if (! System.getDeviceSettings().phoneConnected) {
-            // System.println("HomeAssistantTemplateMenuItem getState(): No Phone connection, skipping API call.");
-            ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoPhone) as Lang.String + ".");
-            getApp().setApiStatus(WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String);
-        } else if (! System.getDeviceSettings().connectionAvailable) {
-            // System.println("HomeAssistantTemplateMenuItem getState(): No Internet connection, skipping API call.");
-            ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoInternet) as Lang.String + ".");
-            getApp().setApiStatus(WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String);
-        } else {
-            // https://developers.home-assistant.io/docs/api/native-app-integration/sending-data/#render-templates
-            var url = Settings.getApiUrl() + "/webhook/" + Settings.getWebhookId();
-            // System.println("HomeAssistantTemplateMenuItem getState() URL=" + url + ", Template='" + mTemplate + "'");
-            Communications.makeWebRequest(
-                url,
-                {
-                    "type" => "render_template",
-                    "data" => {
-                        "request" => {
-                            "template" => mTemplate
-                        }
-                    }
-                },
-                {
-                    :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                    :headers      => {
-                        "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
-                    },
-                    :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
-                },
-                method(:onReturnGetState)
-            );
-        }
-    }
-
 }

source/HomeAssistantToggleMenuItem.mc

@@ -27,9 +27,11 @@ using Toybox.Timer;
 class HomeAssistantToggleMenuItem extends WatchUi.ToggleMenuItem {
     private var mConfirm  as Lang.Boolean;
     private var mData     as Lang.Dictionary;
+    private var mTemplate as Lang.String;
 
     function initialize(
         label    as Lang.String or Lang.Symbol,
+        template as Lang.String,
         confirm  as Lang.Boolean,
         data     as Lang.Dictionary or Null,
         options  as {
@@ -40,6 +42,7 @@ class HomeAssistantToggleMenuItem extends WatchUi.ToggleMenuItem {
         WatchUi.ToggleMenuItem.initialize(label, null, null, false, options);
         mConfirm  = confirm;
         mData     = data;
+        mTemplate = template;
     }
 
     private function setUiToggle(state as Null or Lang.String) as Void {
@@ -88,6 +91,7 @@ class HomeAssistantToggleMenuItem extends WatchUi.ToggleMenuItem {
             case Communications.NETWORK_RESPONSE_OUT_OF_MEMORY:
                 // System.println("HomeAssistantToggleMenuItem onReturnGetState() Response Code: NETWORK_RESPONSE_OUT_OF_MEMORY, are we going too fast?");
                 var myTimer = new Timer.Timer();
+                // Abandon the update to this menu item, and any template, and move on to the next with a back-off delay.
                 // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
                 myTimer.start(getApp().method(:updateNextMenuItem), Globals.scApiBackoff, false);
                 // Revert status
@@ -123,8 +127,13 @@ class HomeAssistantToggleMenuItem extends WatchUi.ToggleMenuItem {
                     setLabel((data.get("attributes") as Lang.Dictionary).get("friendly_name") as Lang.String);
                 }
                 setUiToggle(state);
+                if (mTemplate == null) {
+                    // Nothing more to do
                     // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
                     getApp().updateNextMenuItem();
+                } else {
+                    updateTemplate();
+                }
                 break;
 
             default:
@@ -272,4 +281,127 @@ class HomeAssistantToggleMenuItem extends WatchUi.ToggleMenuItem {
         setState(b);
     }
 
+    // Callback function after completing the GET request to fetch the status.
+    // Terminate updating the toggle menu items via the chain of calls for a permanent network
+    // error. The ErrorView cancellation will resume the call chain.
+    //
+    function onReturnUpdateTemplate(responseCode as Lang.Number, data as Null or Lang.Dictionary) as Void {
+        // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: " + responseCode);
+        // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Data: " + data);
+
+        var status = WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String;
+        switch (responseCode) {
+            case Communications.BLE_HOST_TIMEOUT:
+            case Communications.BLE_CONNECTION_UNAVAILABLE:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: BLE_HOST_TIMEOUT or BLE_CONNECTION_UNAVAILABLE, Bluetooth connection severed.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoPhone) as Lang.String + ".");
+                break;
+
+            case Communications.BLE_QUEUE_FULL:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: BLE_QUEUE_FULL, API calls too rapid.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.ApiFlood) as Lang.String);
+                break;
+
+            case Communications.NETWORK_REQUEST_TIMED_OUT:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: NETWORK_REQUEST_TIMED_OUT, check Internet connection.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoResponse) as Lang.String);
+                break;
+
+            case Communications.INVALID_HTTP_BODY_IN_NETWORK_RESPONSE:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: INVALID_HTTP_BODY_IN_NETWORK_RESPONSE, check JSON is returned.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoJson) as Lang.String);
+                break;
+
+            case Communications.NETWORK_RESPONSE_OUT_OF_MEMORY:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: NETWORK_RESPONSE_OUT_OF_MEMORY, are we going too fast?");
+                var myTimer = new Timer.Timer();
+                // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
+                myTimer.start(getApp().method(:updateNextMenuItem), Globals.scApiBackoff, false);
+                // Revert status
+                status = getApp().getApiStatus();
+                break;
+
+            case 404:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: 404, page not found. Check API URL setting.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.ApiUrlNotFound) as Lang.String);
+                break;
+
+            case 400:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState() Response Code: 400, bad request. Template error.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.TemplateError) as Lang.String);
+                break;
+
+            case 200:
+                status = WatchUi.loadResource($.Rez.Strings.Available) as Lang.String;
+                var label = data.get("request");
+                if (label == null) {
+                    setSubLabel($.Rez.Strings.Empty);
+                } else if(label instanceof Lang.String) {
+                    setSubLabel(label);
+                } else if(label instanceof Lang.Dictionary) {
+                    // System.println("HomeAssistantTemplateMenuItem onReturnGetState() label = " + label);
+                    if (label.get("error") != null) {
+                        setSubLabel($.Rez.Strings.TemplateError);
+                    } else {
+                        setSubLabel($.Rez.Strings.PotentialError);
+                    }
+                } else {
+                    // The template must return a Lang.String, a number can be either integer or float and hence cannot be formatted locally without error.
+                    setSubLabel(WatchUi.loadResource($.Rez.Strings.TemplateError) as Lang.String);
+                }
+                requestUpdate();
+                // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
+                getApp().updateNextMenuItem();
+                break;
+
+            default:
+                // System.println("HomeAssistantTemplateMenuItem onReturnGetState(): Unhandled HTTP response code = " + responseCode);
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.UnhandledHttpErr) as Lang.String + responseCode);
+        }
+        getApp().setApiStatus(status);
+    }
+
+    // Massive code duplication from TemplateMenuItem, but cannot inherit from two classes.
+    //
+    function updateTemplate() as Void {
+        if (mTemplate == null) {
+            // Nothing to do here.
+            // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
+            getApp().updateNextMenuItem();
+        } else {
+            if (! System.getDeviceSettings().phoneConnected) {
+                // System.println("HomeAssistantTemplateMenuItem getState(): No Phone connection, skipping API call.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoPhone) as Lang.String + ".");
+                getApp().setApiStatus(WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String);
+            } else if (! System.getDeviceSettings().connectionAvailable) {
+                // System.println("HomeAssistantTemplateMenuItem getState(): No Internet connection, skipping API call.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoInternet) as Lang.String + ".");
+                getApp().setApiStatus(WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String);
+            } else {
+                // https://developers.home-assistant.io/docs/api/native-app-integration/sending-data/#render-templates
+                var url = Settings.getApiUrl() + "/webhook/" + Settings.getWebhookId();
+                // System.println("HomeAssistantTemplateMenuItem getState() URL=" + url + ", Template='" + mTemplate + "'");
+                Communications.makeWebRequest(
+                    url,
+                    {
+                        "type" => "render_template",
+                        "data" => {
+                            "request" => {
+                                "template" => mTemplate
+                            }
+                        }
+                    },
+                    {
+                        :method       => Communications.HTTP_REQUEST_METHOD_POST,
+                        :headers      => {
+                            "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
+                        },
+                        :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
+                    },
+                    method(:onReturnUpdateTemplate)
+                );
+            }
+        }
+    }
+
 }

source/HomeAssistantView.mc

@@ -62,7 +62,7 @@ class HomeAssistantView extends WatchUi.Menu2 {
                 }
                 if (type != null && name != null) {
                     if (type.equals("toggle") && entity != null) {
-                        addItem(HomeAssistantMenuItemFactory.create().toggle(name, entity, confirm));
+                        addItem(HomeAssistantMenuItemFactory.create().toggle(name, entity, content, confirm));
                     } else if (type.equals("template") && content != null) {
                         if (service == null) {
                             addItem(HomeAssistantMenuItemFactory.create().template_notap(name, content));
@@ -73,7 +73,7 @@ class HomeAssistantView extends WatchUi.Menu2 {
                     } else if (type.equals("tap") && service != null) {
                         addItem(HomeAssistantMenuItemFactory.create().tap(name, entity, service, confirm, data));
                     } else if (type.equals("group")) {
-                        addItem(HomeAssistantMenuItemFactory.create().group(items[i]));
+                        addItem(HomeAssistantMenuItemFactory.create().group(items[i], content));
                     }
                 }
             }
@@ -82,11 +82,16 @@ class HomeAssistantView extends WatchUi.Menu2 {
 
     function getItemsToUpdate() as Lang.Array<HomeAssistantToggleMenuItem or HomeAssistantTemplateMenuItem> {
         var fullList = [];
-
         var lmi = mItems as Lang.Array<WatchUi.MenuItem>;
+
         for(var i = 0; i < mItems.size(); i++) {
             var item = lmi[i];
             if (item instanceof HomeAssistantGroupMenuItem) {
+                // Group menu items can now have an optional template to evaluate
+                var gmi = item as HomeAssistantGroupMenuItem;
+                if (gmi.hasTemplate()) {
+                    fullList.add(item);
+                }
                 fullList.addAll(item.getMenuView().getItemsToUpdate());
             } else if (item instanceof HomeAssistantToggleMenuItem) {
                 fullList.add(item);

source/TemplateMenuItem.mc

@@ -0,0 +1,182 @@
+//-----------------------------------------------------------------------------------
+//
+// Distributed under MIT Licence
+//   See https://github.com/house-of-abbey/GarminHomeAssistant/blob/main/LICENSE.
+//
+//-----------------------------------------------------------------------------------
+//
+// GarminHomeAssistant is a Garmin IQ application written in Monkey C and routinely
+// tested on a Venu 2 device. The source code is provided at:
+//            https://github.com/house-of-abbey/GarminHomeAssistant.
+//
+// P A Abbey & J D Abbey, 24 August 2024
+//
+//
+// Description:
+//
+// Menu button that renders a Home Assistant Template.
+//
+// Reference:
+//  * https://developers.home-assistant.io/docs/api/rest/
+//  * https://www.home-assistant.io/docs/configuration/templating
+//
+//-----------------------------------------------------------------------------------
+
+using Toybox.Lang;
+using Toybox.WatchUi;
+using Toybox.Graphics;
+
+class TemplateMenuItem extends WatchUi.IconMenuItem {
+    private var mTemplate as Lang.String;
+    private var mCallback as Method() as Void;
+
+    function initialize(
+        label    as Lang.String or Lang.Symbol,
+        template as Lang.String,
+        // Do not use Lang.Method as it does not compile!
+        callback as Method() as Void,
+        icon     as Graphics.BitmapType or WatchUi.Drawable,
+        options  as {
+            :alignment as WatchUi.MenuItem.Alignment
+        } or Null
+    ) {
+        WatchUi.IconMenuItem.initialize(
+            label,
+            null,
+            null,
+            icon,
+            options
+        );
+
+        mTemplate = template;
+        mCallback = callback;
+    }
+
+    // Callback function after completing the GET request to fetch the status.
+    // Terminate updating the toggle menu items via the chain of calls for a permanent network
+    // error. The ErrorView cancellation will resume the call chain.
+    //
+    function onReturnGetState(responseCode as Lang.Number, data as Null or Lang.Dictionary) as Void {
+        // System.println("TemplateMenuItem onReturnGetState() Response Code: " + responseCode);
+        // System.println("TemplateMenuItem onReturnGetState() Response Data: " + data);
+
+        var status = WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String;
+        switch (responseCode) {
+            case Communications.BLE_HOST_TIMEOUT:
+            case Communications.BLE_CONNECTION_UNAVAILABLE:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: BLE_HOST_TIMEOUT or BLE_CONNECTION_UNAVAILABLE, Bluetooth connection severed.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoPhone) as Lang.String + ".");
+                break;
+
+            case Communications.BLE_QUEUE_FULL:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: BLE_QUEUE_FULL, API calls too rapid.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.ApiFlood) as Lang.String);
+                break;
+
+            case Communications.NETWORK_REQUEST_TIMED_OUT:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: NETWORK_REQUEST_TIMED_OUT, check Internet connection.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoResponse) as Lang.String);
+                break;
+
+            case Communications.INVALID_HTTP_BODY_IN_NETWORK_RESPONSE:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: INVALID_HTTP_BODY_IN_NETWORK_RESPONSE, check JSON is returned.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoJson) as Lang.String);
+                break;
+
+            case Communications.NETWORK_RESPONSE_OUT_OF_MEMORY:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: NETWORK_RESPONSE_OUT_OF_MEMORY, are we going too fast?");
+                var myTimer = new Timer.Timer();
+                // Now this feels very "closely coupled" to the application, but it is the most reliable method instead of using a timer.
+                myTimer.start(getApp().method(:updateNextMenuItem), Globals.scApiBackoff, false);
+                // Revert status
+                status = getApp().getApiStatus();
+                break;
+
+            case 404:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: 404, page not found. Check API URL setting.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.ApiUrlNotFound) as Lang.String);
+                break;
+
+            case 400:
+                // System.println("TemplateMenuItem onReturnGetState() Response Code: 400, bad request. Template error.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.TemplateError) as Lang.String);
+                break;
+
+            case 200:
+                status = WatchUi.loadResource($.Rez.Strings.Available) as Lang.String;
+                var label = data.get("request");
+                if (label == null) {
+                    setSubLabel($.Rez.Strings.Empty);
+                } else if(label instanceof Lang.String) {
+                    setSubLabel(label);
+                } else if(label instanceof Lang.Dictionary) {
+                    // System.println("TemplateMenuItem onReturnGetState() label = " + label);
+                    if (label.get("error") != null) {
+                        setSubLabel($.Rez.Strings.TemplateError);
+                    } else {
+                        setSubLabel($.Rez.Strings.PotentialError);
+                    }
+                } else {
+                    // The template must return a Lang.String, a number can be either integer or float and hence cannot be formatted locally without error.
+                    setSubLabel(WatchUi.loadResource($.Rez.Strings.TemplateError) as Lang.String);
+                }
+                requestUpdate();
+                if (mCallback != null) {
+                    mCallback.invoke();
+                }
+                break;
+
+            default:
+                // System.println("TemplateMenuItem onReturnGetState(): Unhandled HTTP response code = " + responseCode);
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.UnhandledHttpErr) as Lang.String + responseCode);
+        }
+        getApp().setApiStatus(status);
+    }
+
+    function getState() as Void {
+        if (mTemplate == null) {
+            // Nothing to do here.
+            if (mCallback != null) {
+                mCallback.invoke();
+            }
+        } else {
+            if (! System.getDeviceSettings().phoneConnected) {
+                // System.println("TemplateMenuItem getState(): No Phone connection, skipping API call.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoPhone) as Lang.String + ".");
+                getApp().setApiStatus(WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String);
+            } else if (! System.getDeviceSettings().connectionAvailable) {
+                // System.println("TemplateMenuItem getState(): No Internet connection, skipping API call.");
+                ErrorView.show(WatchUi.loadResource($.Rez.Strings.NoInternet) as Lang.String + ".");
+                getApp().setApiStatus(WatchUi.loadResource($.Rez.Strings.Unavailable) as Lang.String);
+            } else {
+                // https://developers.home-assistant.io/docs/api/native-app-integration/sending-data/#render-templates
+                var url = Settings.getApiUrl() + "/webhook/" + Settings.getWebhookId();
+                // System.println("TemplateMenuItem getState() URL=" + url + ", Template='" + mTemplate + "'");
+                Communications.makeWebRequest(
+                    url,
+                    {
+                        "type" => "render_template",
+                        "data" => {
+                            "request" => {
+                                "template" => mTemplate
+                            }
+                        }
+                    },
+                    {
+                        :method       => Communications.HTTP_REQUEST_METHOD_POST,
+                        :headers      => {
+                            "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
+                        },
+                        :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
+                    },
+                    method(:onReturnGetState)
+                );
+            }
+        }
+    }
+
+    function hasTemplate() as Lang.Boolean {
+        return (mTemplate != null);
+    }
+
+}