[items] Item: Add groupType property to get the type of group (if any) (#476)

Signed-off-by: Florian Hotze <dev@florianhotze.com>

Author: florian-h05

README.md

@@ -417,6 +417,7 @@ Calling `getItem(...)` or `...` returns an `Item` object with the following prop
   - .persistence ⇒ [`ItemPersistence`](#itempersistence)
   - .semantics ⇒ [`ItemSemantics`](https://openhab.github.io/openhab-js/items.ItemSemantics.html)
   - .type ⇒ `string`
+  - .groupType ⇒ `string|null`
   - .name ⇒ `string`
   - .label ⇒ `string`
   - .state ⇒ `string`

src/items/items.js

@@ -112,6 +112,16 @@ class Item {
     return this.rawItem.getType().toString();
   }
 
+  /**
+   * Type of the Group, if this Item is a Group and has a type, else `null`.
+   * @type {string|null}
+   */
+  get groupType () {
+    if (this.type !== 'Group') return null;
+    const baseItem = this.rawItem.getBaseItem();
+    return (baseItem !== null) ? baseItem.getType().toString() : null;
+  }
+
   /**
    * Name of Item
    * @type {string}

types/items/itemchannellink.d.ts

@@ -3,6 +3,7 @@ export type Item = {
     persistence: import("./item-persistence");
     semantics: import("./item-semantics");
     readonly type: string;
+    readonly groupType: string;
     readonly name: string;
     readonly label: string;
     readonly state: string;

types/items/itemchannellink.d.ts.map

@@ -213,6 +213,11 @@ export class Item {
      * @type {string}
      */
     get type(): string;
+    /**
+     * Type of the Group, if this Item is a Group and has a type, else `null`.
+     * @type {string|null}
+     */
+    get groupType(): string;
     /**
      * Name of Item
      * @type {string}

types/items/items.d.ts

@@ -3,6 +3,7 @@ export type Item = {
     persistence: import("./item-persistence");
     semantics: import("./item-semantics");
     readonly type: string;
+    readonly groupType: string;
     readonly name: string;
     readonly label: string;
     readonly state: string;

types/items/items.d.ts.map

@@ -3,6 +3,7 @@ export type Item = {
     persistence: import("./items/item-persistence");
     semantics: import("./items/item-semantics");
     readonly type: string;
+    readonly groupType: string;
     readonly name: string;
     readonly label: string;
     readonly state: string;