JSON schema visualizer

I have the following backbone function to read a JSON schema and draw the tree structure (as in the screenshot below). I want to make sure if checking against the type as object/array is alright or if there is a better way to do it.

traverseJSONSchema: function (root, rootName, level, rank, resultPane) {
    var height = this.nodeHeight,
            width = this.containerWidth,
            margin = width / 6,
            x = 0,
            overhead = rank * margin,
            y = level * height;
    var tempParent = resultPane.append("g").attr("class", "nested-group");
    if (root.type === "object") {
        if (rootName !== "") {
            var nodeText = rootName + ":" + root.type;
            var node = new DataMapper.Models.Node({parent: tempParent, text: nodeText, x: x, y: y, type: this.get('type'), category: "object", height: height, width: width});
            node.drawContainerNode(overhead); //leave overhead space and draw text
            rank++;
            level++;
        }
        var nestedParent = tempParent.append("g").attr("class", "nested-group");
        var keys = root.properties; //select PROPERTIES
        for (var i = 0; i < Object.keys(keys).length; i++) {   //traverse through each PROPERTY of the object
            var keyName = Object.keys(keys)[i];
            var key = keys[keyName];
            level = this.traverseJSONSchema(key, keyName, level, rank, tempParent);
        }
    } else if (root.type === "array") {
        var keys = root.items; //select ITEMS
        if (rootName !== "") {
            var nodeText = rootName + ":" + root.type + "[" + keys.type + "]";
            var node = new DataMapper.Models.Node({parent: tempParent, text: nodeText, x: x, y: y, type: this.get('type'), category: "array", height: height, width: width});
            node.drawContainerNode(overhead);
            rank++;
            level++;
        }
        level = this.traverseJSONSchema(keys, "", level, rank, tempParent); //recurse through the items of array
    } else if (["string", "integer", "number", "boolean"].indexOf(root.type) > -1) {    //when the type is a primitive
        tempParent.classed("nested-group", false);
        if (rootName !== "") {
            var nodeText = rootName + ":" + root.type;
            var node = new DataMapper.Models.Node({parent: tempParent, text: nodeText, x: x, y: y, type: this.get('type'), category: root.type, height: height, width: width});
            node.drawContainerNode(overhead);
            rank++;
            level++;
        }
    }
  return level;
}