Select2 autocomplete by parameter value

Question

I tried integrating tag / autocomplete for my site. It works through option text. I am almost close to the result, but still hanging.

Now when you try to select the option text, the corresponding text will appear. But now I want to show kathmandu or a related search for option text through the parameter value.

Example: when we look for the value a001 kathmandu , will appear and select the same that a002 appears pokhara

$("select").select2({
  tags: "true",
  placeholder: "Select an option",
  allowClear: true,
  width: '100%',
  createTag: function (params) {
    var term = $.trim(params.term);

    if (term === '') {
      return null;
    }

    return {
     id: term,
     text: term,
     value: true // add additional parameters
    }
  }
});

.select2-container {
  max-width: 400px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.min.css" rel="stylesheet"/>
<select class="custom-select"  multiple="multiple">
  <option value="a001">Kathmandu</option>
  <option value="a002">Pokhara</option>
  <option value="a003">Lalitpur</option>
</select>

Run codeHide result

, , . , pokhara kathmandu, .

Answer 1

Id Text Id, , Id, Text :

options = [];

// create an array of select options for a lookup
$('.custom-select option').each(function(idx) {
    options.push({id: $(this).val(), text: $(this).text()});
});


$("select").select2({
  tags: "true",
  placeholder: "Select an option",
  allowClear: true,
  width: '100%',
  createTag: function (params) {
    var term = $.trim(params.term);

    if (term === '') {
      return null;
    }
    
    // check whether the term matches an id
    var search = $.grep(options, function( n, i ) {
      return ( n.id === term || n.text === term); // check against id and text
    });
    
    // if a match is found replace the term with the options' text
    if (search.length) 
      term = search[0].text;
    else
      return null; // didn't match id or text value so don't add it to selection
    
    return {
     id: term,
     text: term,
     value: true // add additional parameters
    }
  }
});

$('select').on('select2:select', function (evt) {
  //console.log(evt);
  //return false;
});

.select2-container {
  max-width: 400px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.min.css" rel="stylesheet"/>
<select class="custom-select"  multiple="multiple">
  <option value="a001">Kathmandu</option>
  <option value="a002">Pokhara</option>
  <option value="a003">Lalitpur</option>
</select>

Hide result

Answer 2

a001, . placeholder.

, 2 . , , , . , .

: a001 kathmandu a001

, placeholder select2

placeholder: {
        id: "-1",
        text: "Select an option",
      } 

$("select").select2({
  tags: "true",
  placeholder: {
    id: "-1",
    text: "Select an option",
  }, 
  allowClear: true,
  width: '100%',
  createTag: function(params) {
    var term = $.trim(params.term);

    if (term === '') {
      return null;
    }

    return {
      id: term,
      text: term,
      value: true // add additional parameters
    }
  }
});

.select2-container {
  max-width: 400px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.min.css" rel="stylesheet" />
<select class="custom-select" multiple="multiple">
  <option value="a001">Kathmandu</option>
  <option value="a002">Pokhara</option>
  <option value="a003">Lalitpur</option>
</select>

Hide result