Populating a JSTree with JSON data obtained in AJAX

Question

I'm trying to populate a JSTree with JSON data that I'm obtaining from a service (which is called using ajax). However, I am getting a "Neither data nor ajax settings supplied error" in the jquery.jstree.js file. Because of this the JSTree just displays a loading gif.

AJAX code (editted to try setting json to local variable test, then return test)

function getJSONData() {
    var test;
    $
            .ajax({
                async : true,
                type : "GET",
                url : "/JavaTestService/rs/TestService/MyFirstTestService?languageCode=en_US&version=2",
                dataType : "json",

                success : function(json) {
                    test = json;
                },

                error : function(xhr, ajaxOptions, thrownError) {
                    alert(xhr.status);
                    alert(thrownError);
                    test = "error";
                }
            });
    return test;
}

JSTree code

var jsonData = getJSONData();
createJSTrees(jsonData);

function createJSTrees(jsonData) {
        $("#supplierResults").jstree({
            "json_data" : {
                "data" : jsonData
            },
            "plugins" : [ "themes", "json_data", "ui" ]
        });

After some debugging, I've found that jsonData is undefined when passed to the createJSTrees method. Am I retrieving that data correctly in the Ajax code? Thanks in advance

Answer 1

jsonData is undefined because getJSONData() doesn't return a value. You can't rely on the return value from your $.ajax success handler unless you assign a variable local to getJSONData() that gets returned after the $.ajax call completes. But you want something like this, which also has the benefit of being asynchronous:

<script type="text/javascript">    

$(function() {
    $.ajax({
        async : true,
        type : "GET",
        url : "/JavaTestService/rs/TestService/MyFirstTestService?languageCode=en_US&version=2",
        dataType : "json",    

        success : function(json) {
            createJSTrees(json);
        },    

        error : function(xhr, ajaxOptions, thrownError) {
            alert(xhr.status);
            alert(thrownError);
        }
    });
});    

function createJSTrees(jsonData) {
    $("#supplierResults").jstree({
        "json_data" : {
            "data" : jsonData
        },
        "plugins" : [ "themes", "json_data", "ui" ]
    });
}    

</script>

Answer 2

I have not tested your approach before, where you supply the data parameter directly to the json_data plugin, so I won't be able to supply an answer to this scenario.

However, since you are using an AJAX call to get the data, can't you supply the AJAX call to JSTree and let it handle the call on its own? Here's how I've configured the AJAX call in my code:

        (...)
        'json_data': {
            'ajax': {
                'url': myURL,
                'type': 'GET',
                'data': function(node) {
                    return {
                        'nodeId': node.attr ? node.attr("id") : ''
                    };
                }
            },
            'progressive_render': true,
            'progressive_unload': false
        },
        (...)