成功时select2检索新创建的标签ID

In select2 I have tags loaded by AJAX, if the tag is not found in the db then the user has the option to create a new one. The issue is that the new tag is listed in the select2 box as a term and not as the id (what select to wants - especially becomes a problem when loading the tags again if the user wants to update since only the term and not the id is stored in the db). How can I, on success of adding the term, make it so that select2 recieves the ID and submits the ID instead of the tag name/term?

$(document).ready(function() {
var lastResults = [];
$("#project_tags").select2({
    multiple: true,
    placeholder: "Please enter tags",
    tokenSeparators: [","],
    initSelection : function (element, callback) {
        var data = [];
        $(element.val().split(",")).each(function () {
            data.push({id: this, text: this});
        });
        callback(data);
    },
    ajax: {
        multiple: true,
        url: "framework/helpers/tags.php",
        dataType: "json",
        data: function(term) {
            return {
                term: term
            };
        },
        results: function(data) {
            return {
                results: data
            };
        }
    },
    createSearchChoice: function(term) {
        var text = term + (lastResults.some(function(r) {
            return r.text == term
        }) ? "" : " (new)");
        return {
            id: term,
            text: text
        };
    },
});
$('#project_tags').on("change", function(e) {
    if (e.added) {
        if (/ \(new\)$/.test(e.added.text)) {
            var response = confirm("Do you want to add the new tag " + e.added.id + "?");
            if (response == true) {
                alert("Will now send new tag to server: " + e.added.id);
                $.ajax({
                    url: 'framework/helpers/tags.php',
                    data: {
                        action: 'add',
                        term: e.added.id
                    },
                    success: function(data) {

                    },
                    error: function() {
                        alert("error");
                    }
                });
            } else {
                console.log("Removing the tag");
                var selectedTags = $("#project_tags").select2("val");
                var index = selectedTags.indexOf(e.added.id);
                selectedTags.splice(index, 1);
                if (selectedTags.length == 0) {
                    $("#project_tags").select2("val", "");
                } else {
                    $("#project_tags").select2("val", selectedTags);
                }
            }
        }
    }
});

});

Heres part of the switch that does the adding

case 'add':
    if (isset($_GET['term'])) {
        $new_tag = escape($_GET['term']);
        if (Nemesis::insert('tags', 'tag_id, tag_content', "NULL, '{$new_tag}'")) {
            // we need to send back the ID for the newly created tag
            $search = Nemesis::select('tag_id', 'tags', "tag_content = '{$new_tag}'");
            list($tag_id) = $search->fetch_row();
            echo $tag_id;
        } else {
            echo 'Failure';
        }
        exit();
    }
    break;

UPDATE: I've done a bit of digging, and what confuses me is that the select2 input does not seem to store the associated ID for the tag/term (see below). I know I could change the attribute with the success callback, but I don't know what to change!

As you have said, you can replace that value, and that is what my solution does. If you search the Element Inspector of Chrome, you will see, bellow the Select2 field, an input with the id project_tags and the height of 1.

The weird thing is that the element inspector of Chrome does not show you the values of the input, as you can see below:

However, you do a console.log($("#project_tags").val()) the input has values (as you see in the image).

So, you can simply replace the text of the new option by the id, inside the success function of the ajax call placed within the $('#project_tags').on("change") function. The ajax call will be something like:

$.ajax({
    url: 'framework/helpers/tags.php',
    data: {
        action: 'add',
        term: e.added.id
    },
    success: function(tag_id) {
        var new_val = $("#project_tags")
                        .val()
                        .replace(e.added.id, tag_id);
        $("#project_tags").val(new_val);
    },
    error: function() {
        alert("error");
    }
});

Please be aware that this solution is not bullet proof. For example, if you have a tag with the value 1 selected, and the user inserts the text 1, this will cause problems.

Maybe a better option would be replace everything at the right of the last comma. However, even this might have cause some problems, if you allow the user to create a tag with a comma.

Let me know if you need any more information.