Select2 search with world_countries

Question

I connected https://github.com/stefangabos/world_countries cdn list with select2 to list all countries. Does anybody know how to search within countries?

var countriesList = 'https://cdn.jsdelivr.net/npm/world_countries_lists@latest/data/en/countries.json';

$('select').select2({
  ajax: {
    url: countriesList,
    dataType: 'json',
    delay: 250,
    data: function (params) {
      console.log(params.term);
      return {
        q: params.term
      };
    },
    processResults: function (data) {
      return {
        results: $.map(data, function (item) {
          return {
            id: item.id,
            text: item.name
          };
        })
      };
    }
  },
  width: 300,
  dropdownAutoWidth: true
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/select2@4.1.0-beta.1/dist/js/select2.min.js"></script>
<link href="https://cdn.jsdelivr.net/npm/select2@4.1.0-beta.1/dist/css/select2.min.css" rel="stylesheet"/>

<select></select>

Answer 1

Because your data source is a JSON file so passing search term to url will not change the response. In this case, you can load this file once then init select2 with the response:

var countriesList = 'https://cdn.jsdelivr.net/npm/world_countries_lists@latest/data/en/countries.json';

$.ajax({
    type: 'GET',
    url: countriesList,
    dataType: 'json',
    success: function(response) {
        $('select').select2({
          data: response.map(e => ({
            id: e.id,
            text: e.name
          })),
          width: 300,
          dropdownAutoWidth: true
        });
    },
    error: function() {},
    complete: function() {}
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/select2@4.1.0-beta.1/dist/js/select2.min.js"></script>
<link href="https://cdn.jsdelivr.net/npm/select2@4.1.0-beta.1/dist/css/select2.min.css" rel="stylesheet"/>

<select></select>

Or if you still want to use select2 with ajax, you can filter response with search term in processResults(not recommended):

var countriesList = 'https://cdn.jsdelivr.net/npm/world_countries_lists@latest/data/en/countries.json';

$('select').select2({
  ajax: {
    url: countriesList,
    dataType: 'json',
    delay: 250,
    data: function (params) {
      return {
        q: params.term
      };
    },
    processResults: function (data) {
      let term = this.container.results.lastParams.term;
      if (term) data = data.filter(d => d.name.includes(term));
      return {
        results: $.map(data, function (item) {
          return {
            id: item.id,
            text: item.name
          };
        })
      };
    }
  },
  width: 300,
  dropdownAutoWidth: true
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/select2@4.1.0-beta.1/dist/js/select2.min.js"></script>
<link href="https://cdn.jsdelivr.net/npm/select2@4.1.0-beta.1/dist/css/select2.min.css" rel="stylesheet"/>

<select></select>