Select2 Dependent dropdown lists

Question

I am trying to use the Select2 plugin to have 4 dropdown lists that depend on each other. I have struggled to find the right way to update the data that loads the options in.

My goal is to load the new data via ajax, but once I have it in the client I am unable to add the new data to the select list.

The code I have tried is here:

$(#"a3").select2({
    placeholder: "select an item",
    allowClear: true}).on("change",
    function (e) {
         var results = $.get("url?id=2",
            function (data, textStatus, jqXHR) {
                $(this).select2({ data: { results: data, text: "Name" } });
        });
    }
); 

There is another question here select2 changing items dynamically but the solution there worked with Select2 v3.2 but not Select2 v3.3

Answer 1

Igor has come back to me with a way to do this

var data=[...];    
$().select2({data: function() {return {results:data};}});    
/// later    
data=[...something else];    
// next query select2 will use 'something else' data

Answer 2

The correct format is:

.select2("data", {...})

Answer 3

For Select2 v4.x, here is a small js class.

Using this, options of a select2 list box will be loaded/refreshed by ajax based on selection of another select2 list box. And the dependency can be chained.

For example -

new Select2Cascade($('#country'), $('#province'), 'path/to/geocode', {type:"province", parent_id: ''});
new Select2Cascade($('#province'), $('#district'), 'path/to/geocode', {type:"district", parent_id: ''});

Check the demo on codepen. Also here is a post on how to use it.