Select2 open dropdown on focus

Question

I have a form with multiple text inputs and some select2 elements. Using the keyboard to tab between fields works fine - the Select2 element behaves like a form element and

Answer 1

For Version 3.5.4 ^{(Aug 30, 2015 and earlier)}

The current answer is only applicable to versions 3.5.4 and before, where select2 fired blur and focus events (select2-focus & select2-blur). It attaches a one-time use handler using $.one to catch the initial focus, and then reattaches it during blur for subsequent uses.

$('.select2').select2({})
  .one('select2-focus', OpenSelect2)
  .on("select2-blur", function (e) {
    $(this).one('select2-focus', OpenSelect2)
  })

function OpenSelect2() {
  var $select2 = $(this).data('select2');
  setTimeout(function() {
    if (!$select2.opened()) { $select2.open(); }
  }, 0);  
}

I tried both of @irvin-dominin-aka-edward's answers, but also ran into both problems (having to click the dropdown twice, and that Firefox throws 'event is not defined').

I did find a solution that seems to solve the two problems and haven't run into other issue yet. This is based on @irvin-dominin-aka-edward's answers by modifying the select2Focus function so that instead of executing the rest of the code right away, wrap it in setTimeout.

Demo in jsFiddle & Stack Snippets

$('.select2').select2({})
  .one('select2-focus', OpenSelect2)
  .on("select2-blur", function (e) {
    $(this).one('select2-focus', OpenSelect2)
  })

function OpenSelect2() {
  var $select2 = $(this).data('select2');
  setTimeout(function() {
    if (!$select2.opened()) { $select2.open(); }
  }, 0);  
}

body {
  margin: 2em;
}

.form-control {
  width: 200px;  
  margin-bottom: 1em;
  padding: 5px;
  display: flex;
  flex-direction: column;
}

select {
  border: 1px solid #aaa;
  border-radius: 4px;
  height: 28px;
}

  
  

    Normal
    
      
      Apple
      Banana
      Carrot
      Donut
    



  Select2
  
    
    Apple
    Banana
      Carrot
      Donut