Add combobox groups

shared/tree.ts

@@ -111,6 +111,22 @@ export class Tree<T extends Omit<LocalContent, 'content'>>
 
         return recursive(1, this._data);
     }
+    static each<T extends Record<string, any>>(tree: Array<T | undefined>, children: keyof T, callback: (item: T, depth: number, parent?: T) => void)
+    {
+        const recursive = (depth: number, data?: Array<T | undefined>, parent?: T) => data?.forEach(e => { if(!e) return; callback(e, depth, parent); !Array.isArray(e[children]) ? undefined : recursive(depth + 1, e[children] as T[] | undefined, e) });
+
+        recursive(1, tree);
+    }
+    static accumulate<T extends Record<string, any>>(tree: Array<T | undefined>, children: keyof T, callback: (item: T, depth: number, parent?: T) => any): any[]
+    {
+        const recursive = (depth: number, data?: Array<T | undefined>, parent?: T): any[] => data?.flatMap(e => e && [callback(e, depth, parent), ...!Array.isArray(e[children]) ? [] : recursive(depth + 1, e[children] as T[] | undefined, e)]) ?? [];
+
+        return recursive(1, tree);
+    }
+    static flatten<T extends Record<string, any>>(tree: T[], children: keyof T): T[]
+    {
+        return Tree.accumulate(tree, children, (item) => item);
+    }
     get data()
     {
         return this._data;