The editor 'combotreegrid' behaviors as the combo + treegrid. The delay loading functionality is the built-in feature. Please refer to this code:
var combotreegridEditor = {
type: 'combotreegrid',
options: {
columns: [[
{field:'name',title:'Name',width:250},
{field:'quantity',title:'Quantity',width:100}
]],
url: 'test2.php',
idField: 'id',
treeField: 'name',
panelWidth: 600
}
}
If your issue continues, please provide an example to demonstrate your issue.