input_treeview
input_treeview(
    id,
    items,
    *,
    selected=None,
    expanded=None,
    multiple=False,
    checkbox=False,
    width=None,
)Create a treeview component to navigate and select items from a hierarchical data structure.
Supports single or multiple selection. Nested levels can be expanded and collapsed.
Parameters
id :str- 
The input id.
 items :list[TreeItem]- 
A list of TreeItem objects representing the tree data.
 selected :str|list[str] = None- 
Initially selected item ID(s). If None (default), no items are selected.
 expanded :str|list[str] = None- 
Initially expanded item ID(s). If None (default), ensures selected items are visible by expanding their parents.
 multiple :bool= False- 
Whether to allow multiple selection.
 checkbox :bool= False- 
Whether to show checkboxes for selection.
 width :str= None- 
The CSS width of the input component (e.g., “400px”, “100%”).
 
Returns
:Tag- 
An element used when creating your Shiny app UI.
 
Notes
If multiple=False, the server value is a string with the ID of the selected item. If multiple=True, the server value is a tuple of the selected item IDs. When nothing is selected, the server value is None in both cases.