Select2 open dropdown on focus text input

Question

I have a form with one text input and one select2 element (Version 4.0.0). I want when focus on text input, the select2 open.

Here’s what I’ve tried :

<select list="userAccountsMap.values" listKey="accountNo" listValue="accountNo"/>
<input id="destinationAccount" type="text" name="destinationAccount">

<script type="text/javascript">

('select').each(function( index ) {
         $(this).select2();
     }
});

$("#destinationAccount").focus(function () {    
   $("select").trigger('select2:open');
});

</script>

But it is not work. See fiddle here: http://jsfiddle.net/Hatamikhah/73wypp1w/1/

I don't understand what my problem is.

Solution

They have explained with example for how to open drop-down option.

Documentation URL: https://select2.github.io/examples.html and please check Programmatic access section.

HTML Part:

<select id="e1">
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select> 
<br>
<br>
<input type="text" id="nameID" name="firstname">

jQuery Part:

$("#e1").select2();

// With change event
$("input").on("change", function () {
    $("#e1").select2("open");
});

// With focus event 
$( "input" ).focus(function() {
  $("#e1").select2("open");
});

Try this example with onChange event: http://jsfiddle.net/mananpatel/73wypp1w/5/

Let me know if you need help :)