Collapses node with id. Returns undefined.

Description

The node must exists in the .nodes array of the sidebar or its nested nodes. The node is identified by the .id property. The method will set .expanded property of the node to false. The method emits .onCollapse event. If you have defined object in the following way: let sidebar = new w2sidebar({ name : 'sidebar', img : 'icon-page', nodes: [ { id: 'id-1', text: 'Level 1', hidden: true }, { id: 'id-2', text: 'Level 2', expanded: true, nodes: [ { id: 'id-2-1', text: 'Level 2.1' }, { id: 'id-2-2', text: 'Level 2.2' } ]}, { id: 'id-3', text: 'Level 3' } ] }); You can: w2ui.sidebar.collapse('id-2');