问回传默认情况下用PHP检查的JSTree列表项

EN

echo '<li class="jstree-checked" id="id">List Item that should be checked on load but its not</li>';

    <script>    
    var select_data = '';

    $(function () {
        $("#tree").jstree({
            "checkbox": {
                'keep_selected_style': false,
'three_state': false,
'cascade': '',
            },
                "plugins": ["checkbox"],    
        });
        $("#tree").bind("changed.jstree",
            function (e, data) {
                console.log(data);

                select_data = JSON.stringify(data.selected);

            }
        );
    }); 


    $.jstree._reference('#tree').check_node('#test'); 

    function upload() {

        var xhttp = new XMLHttpRequest();
        xhttp.onreadystatechange = function() {
            if (this.readyState == 4 && this.status == 200) {
                alert(this.responseText);
            }
        };

        var url = "../../jstree/ajax.php?select_data=" + select_data;

        xhttp.open("GET", url, true);
        xhttp.send(); 
    }
    </script>