Creating an item if not already exists in Selectiz

Question

I was using Selectize.js in a select box, What i need is, if an item is not in the list of options i would need to add a new item. When new item is added, i want to have an ajax call to update the newly added item to my database.

In their documentiation, it says that we can use "create" to have the selectize to add an item.

create - Allows the user to create a new items that aren't in the list of options. This option can be any of the following: "true" (default behavior), "false" (disabled), or a function that accepts two arguments: "input" and "callback". The callback should be invoked with the final data for the option.

But i am not able to understand how to use the call back here. can anyone help?

The following is an example of my content, the values are ids of the items in the db. I would like to have the new item added to db and returned with the value as id from db and populate and get selected in the select box.

<select name="fruits" id="fruits" placeholder="Select a fruit" >
    <option value="1">Apple</option>
    <option value="2">Orange</option>
    <option value="3">Mango</option>
    <option value="4">Grape</option>
</select>

<script>
    $(function(){
        $('#fruits').selectize({
            create:function (input, callback){

           }
        });
    });
</script>

Answer 1

You have to invoke the callback, passing your values:

$('#fruits').selectize({
    create:function (input, callback){
        callback({
            value: 123, // probably your ID created or something
            text: input
        });
    }
});

Answer 2

Actually you must return an object with properties that match the names for your labelField and valueField options:

<script>
    $(function(){
        $('#fruits').selectize({
            create:function (input){
               return { value:123, text:input};
           }
        });
    });
</script>

If you needed to perform a remote operation you would code it like this:

<script>
    $(function(){
        $('#fruits').selectize({
            create:function (input, callback){
                $.ajax({
                    url: '/remote-url/',
                    type: 'GET',
                    success: function (result) {
                        if (result) {
                            callback({ value: result.id, text: input });
                        }
                    }
                });
            }
        });
    });
</script>

Answer 3

Thanks a lot, @Corgalore. Its working for me like
$(function(){
        $('#desig').selectize({
            create:function (input, callback){
                $.ajax({
                    url: "<?php  echo $this->url(null, array('controller' => 'employee-detail', 'action' => 'add-new-desig-ajax'));?>",
                    type: 'POST',
                    data:{'designation':input},
                    success: function (result) {
                        if (result) {
//                            console.log('sdfasf',result);
                            callback({ value: result.id, text: input });
                        }
                    }
                });
            }
        });
    });