select2/docs/options.html

---
layout: default
title: Options - Select2
slug: options
---

<div class="container">
  <section id="core">
    <div class="page-header">
      <h1>Core options</h1>
    </div>

    <p>
      Select2 supports a small subset of options in every build that is
      generated. Each option typically has a decorator that is required that
      wraps an adapter, adding support for the option. This is only required
      when a custom adapter is being used, as Select2 will build the required
      adapters by default.
    </p>

    <h2>
      Display
    </h2>

    <h3 id="placeholder">
      Placeholders
    </h3>

    <p>
      Select2 can display a placeholder for a single-value select that will
      replace an option, or be shown when no options are selected for
      multiple-value selects. You can find an example on the
      <a href="examples.html#placeholders">example page</a>.
    </p>

    <div class="row">
      <div class="col-sm-4">
        <dl class="dl-horizontal">
          <dt>Key</dt>
          <dd>
            <code>placeholder</code>
          </dd>

          <dt>Value</dt>
          <dd>string or object</dd>
        </dl>

        <hr />

        <dl class="dl-horizontal">
          <dt>Adapter</dt>
          <dd>
            <code title="select2/selection/base">SelectionAdapter</code>
          </dd>

          <dt>Decorator</dt>
          <dd>
            <code title="select2/selection/placeholder">Placeholder</code>
          </dd>
        </dl>
      </div>

      <div class="col-sm-8">
        <div class="alert alert-warning">
          <strong>Heads up!</strong>
          Because browsers assume that the first <code>option</code> in
          single-value select boxes is selected, you must add an empty
          <code>&lt;option&gt;&lt;/option&gt;</code> tag that the placeholder
          should use, or it will not work.
        </div>
      </div>
    </div>

    <p>
      If the <strong>value is a string</strong>, the placeholder will be
      displayed when a <strong>blank option</strong> is used as the placeholder.
      The <strong>value</strong> will be the message to show to users as the
      placeholders.
    </p>

    <p>
      If the <strong>value is an object</strong>, the object should be
      compatible with Select2's internal objects. The <code>id</code> should
      be the id to look for when determining if the placeholder should be
      displayed. The <code>text</code> should be the placeholder to display
      when that option is selected.
    </p>

    <div class="alert alert-info">
      You <strong>pass in an object</strong> when you are using a framework that
      <strong>creates its own placeholder option</strong>. The
      <strong>id</strong> should be the same as the <code>value</code>
      attribute on the <code>option</code>.
    </div>

    <h3 id="translation">
      Internationalization (Language support)
    </h3>

    <p>
      Messages will be displayed to users when necessary, such as when no
      search results were found or more characters need to be entered in order
      for a search to be made. These messages have been
      <a href="community.html#translations">translated into many languages</a>
      by contributors to Select2, but you can also provide your own
      translations.
    </p>

    <div class="row">
      <div class="col-sm-4">
        <dl class="dl-horizontal">
          <dt>Key</dt>
          <dd><code>language</code></dd>

          <dt>Value</dt>
          <dd>object or string</dd>
        </dl>

        <hr />

        <dl class="dl-horizontal">
          <dt>Module</dt>
          <dd>
            <code title="select2/translation">Translation</code>
          </dd>
        </dl>
      </div>

      <div class="col-sm-8">
        <p class="alert alert-warning">
          <strong>Heads up!</strong> When using translations provided by Select2,
          you must make sure to include the translation file in your page after
          Select2.
        </p>
      </div>
    </div>

    <p>
      When a string is passed in as the language, Select2 will try to resolve
      it into a language file. This allows you to specify your own language
      files, which must be defined as an AMD module. If the language file
      cannot be found, Select2 will assume it is a language code controlled by
      Select2, and it will try to load the translations for that language
      instead.
    </p>

    <p>
      You can include your own translations by providing an object similar to
      the one below.
    </p>

<pre class="prettyprint">
language: {
  // You can find all of the options in the language files provided in the
  // build. They all must be functions that return the string that should be
  // displayed.
  inputTooShort: function () {
    return "You must enter more characters...";
  }
}
</pre>

    <h2>
      Results
    </h2>

    <p>
      Select2 can work on many different data sets ranging from local options,
      the same way that a <code>&lt;select&gt;</code> typically works, from
      remove options where a server generates the results that users can select
      from.
    </p>

    <h3 id="data">
      Array
    </h3>

    <p>
      Select2 allows creating the results based on an array of data objects that
      is included when initializing Select2.
    </p>

    <div class="row">
      <div class="col-sm-6">
        <dl class="dl-horizontal">
          <dt>Key</dt>
          <dd><code>data</code></dd>

          <dt>Value</dt>
          <dd>array of objects</dd>
        </dl>
      </div>

      <div class="col-sm-6">
        <dl class="dl-horizontal">
          <dt>Adapter</dt>
          <dd>
            <code title="select2/data/array">ArrayAdapter</code>
          </dd>
        </dl>
      </div>
    </div>

    <p>
      The objects that the users can select from should be passed as an array
      with each object containing <code>id</code> and <code>text</code>
      properties.
    </p>

    <h3 id="ajax">
      AJAX
    </h3>

    <p>
      Select2 allows searching for results from remote data sources using AJAX
      requests.
    </p>

    <div class="row">
      <div class="col-sm-6">
        <dl class="dl-horizontal">
          <dt>Key</dt>
          <dd><code>ajax</code></dd>

          <dt>Value</dt>
          <dd>object</dd>
        </dl>
      </div>

      <div class="col-sm-6">
        <dl class="dl-horizontal">
          <dt>Adapter</dt>
          <dd>
            <code title="select2/data/ajax">AjaxAdapter</code>
          </dd>
        </dl>
      </div>
    </div>

    <p>
      All options passed to this option will be directly passed to the
      <code>$.ajax</code> function that executes AJAX requests. There are a few
      custom options that Select2 will intercept, allowing you to customize the
      request as it is being made.

<pre class="prettyprint">
ajax: {
  // The number of milliseconds to wait for the user to stop typing before
  // issuing the ajax request.
  delay: 250,
  // You can craft a custom url based on the parameters that are passed into the
  // request. This is useful if you are using a framework which has
  // JavaScript-based functions for generating the urls to make requests to.
  //
  // @param params The object containing the parameters used to generate the
  //   request.
  // @returns The url that the request should be made to.
  url: function (params) {
    return UrlGenerator.Random();
  },
  // You can pass custom data into the request based on the parameters used to
  // make the request. For `GET` requests, the default method, these are the
  // query parameters that are appended to the url. For `POST` requests, this
  // is the form data that will be passed into the request. For other requests,
  // the data returned from here should be customized based on what jQuery and
  // your server are expecting.
  //
  // @param params The object containing the parameters used to generate the
  //   request.
  // @returns Data to be directly passed into the request.
  data: function (params) {
    var queryParameters = {
      q: params.term
    }

    return queryParameters;
  },
  // You can modify the results that are returned from the server, allowing you
  // to make last-minute changes to the data, or find the correct part of the
  // response to pass to Select2. Keep in mind that results should be passed as
  // an array of objects.
  //
  // @param data The data as it is returned directly by jQuery.
  // @returns An array of objects that will be rendered by Select2.
  processResults: function (data) {
    return data;
  }
}
</pre>
    </p>

    <h3 id="tags">
      Tags
    </h3>

    <p>
      Users can create their own options based on the text that they have
      entered.
    </p>

    <div class="row">
      <div class="col-sm-6">
        <dl class="dl-horizontal">
          <dt>Key</dt>
          <dd><code>tags</code></dd>

          <dt>Value</dt>
          <dd>boolean / array of objects</dd>
        </dl>
      </div>

      <div class="col-sm-6">
        <dl class="dl-horizontal">
          <dt>Adapter</dt>
          <dd>
            <code title="select2/data/base">DataAdapter</code>
          </dd>

          <dt>Decorator</dt>
          <dd>
            <code title="select2/data/tags">Tags</code>
          </dd>
        </dl>
      </div>
    </div>

    <p>
      If the <code>tags</code> option is passed into Select2, if a user types
      anything into the search box which doesn't already exist, it will be
      displayed at the top and the user will be able to select it.
    </p>

    <p>
      <strong>For backwards compatibility</strong>, if an array of objects is
      passed in with the <code>tags</code> option, the options will be
      automatically created and the user will be able to select from them.
      This is the <strong>same as how <a href="#data">array data</a>
      works</strong>, and has similar limitations.
    </p>
  </section>

  <section id="adapters">
    <div class="page-header">
      <h1>Adapters</h1>
    </div>
  </section>
</div>

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