Fix that toHierarchy couldn't be found. Updated docs and test.

docs/src/COMPONENT_API.json

@@ -17777,18 +17777,6 @@
           "isFunctionDeclaration": false,
           "isRequired": false,
           "constant": false,
-          "reactive": true
-        },
-        {
-          "name": "nodesFlat",
-          "kind": "let",
-          "description": "Provide a flat array of nodes to render",
-          "type": "Array<TreeNode & {pid?: any}>",
-          "value": "[]",
-          "isFunction": false,
-          "isFunctionDeclaration": false,
-          "isRequired": false,
-          "constant": false,
           "reactive": false
         },
         {
@@ -17887,6 +17875,18 @@
           "constant": false,
           "reactive": false
         },
+        {
+          "name": "toHierarchy",
+          "kind": "function",
+          "description": "Create a nested array from a flat array",
+          "type": "(flatArray: TreeNode[] & { pid?: any }[]) => TreeNode[]",
+          "value": "() => {\n  return th(flatArray);\n}",
+          "isFunction": true,
+          "isFunctionDeclaration": true,
+          "isRequired": false,
+          "constant": false,
+          "reactive": false
+        },
         {
           "name": "expandNodes",
           "kind": "function",

docs/src/pages/components/TreeView.svx

@@ -58,14 +58,6 @@ To render a node with an icon, define an `icon` property with a Carbon Svelte ic
 
 <FileSource src="/framed/TreeView/TreeViewIcons" />
 
-## Flat data structure
-
-Provide a flat data structure through the `nodesFlat` property. Child object needs to have a `pid` property 
-to reference its parent. Optionally the key for the parent can be provided. 
-When no parent id is available the object is assumed to be at the root of the tree. 
-
-<FileSource src="/framed/TreeView/TreeViewFlatArray" />
-
 ## Initial expanded nodes
 
 Expanded nodes can be set using `expandedIds`.
@@ -116,3 +108,13 @@ Use the `TreeView.showNode` method to show a specific node.
 If a matching node is found, it will be expanded, selected, and focused.
 
 <FileSource src="/framed/TreeView/TreeViewShowNode" />
+
+## Flat data structure
+
+Use the `toHierarchy` method to provide a flat data structure to the `nodes` property.
+
+This method will transform a flat array of objects into the hierarchical array as expected by `nodes`. 
+The child objects in the flat array need to have a `pid` property to reference its parent.
+When `pid` is not provided the object is assumed to be at the root of the tree.
+
+<FileSource src="/framed/TreeView/TreeViewFlatArray" />