Question title

How to progressively load sub-nodes in a list with the VTable component?

Problem description

Using the VTable table component, how to gradually load sub-nodes in the list, click the expand button of the parent node, and then dynamically load the information of the sub-node

Solution

VTable provides setRecordChildren API to update the sub-node status of a node, which can be used to implement progressive loading function

• Data preparation
  Normally, in the data of the tree structure list, the children attribute is an array, which is the sub-node information of the node
  

{
    name: 'a',
    value: 10,
    children: [
        {
            name: 'a-1',
            value: 5,
            children: [
                // ......
            ]
        },
        // ......
    ]
}</br>

How to dynamically load sub-node information, you can configure the children property to true . At this time, the node will be displayed as the parent node in the table, but clicking the expand button in the cell will trigger relevant events, but the table will not have any active changes.

• Monitoring events
  After the expand button is clicked, the VTable. ListTable.EVENT_TYPE event will be triggered. You need to listen to this event and use the setRecordChildren API to update the sub-node information
  

const { TREE_HIERARCHY_STATE_CHANGE } = VTable.ListTable.EVENT_TYPE;
instance.on(TREE_HIERARCHY_STATE_CHANGE, args => {
  if (args.hierarchyState === VTable.TYPES.HierarchyState.expand && !Array.isArray(args.originData.children)) {
    setTimeout(() => {
      const children = [
        {
          name: 'a-1',
          value: 5,
        },
        {
          name: 'a-2',
          value: 5
        }
      ];
      instance.setRecordChildren(children, args.col, args.row);
    }, 200);
  }
});</br>

Code example

demo：https://visactor.io/vtable/demo/table-type/list-table-tree-lazy-load

Related Documents

Related api: https://visactor.io/vtable/option/ListTable-columns-text#tree
Tutorial: https://visactor.io/vtable/guide/table_type/List_table/tree_list
github：https://github.com/VisActor/VTable