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How can I use JSON data to populate the options of a select box?

Posted by: admin November 29, 2017 Leave a comment

Questions:

I need to feed cities based on country of selection. I did it programmically but have no idea how to put JSON data into the select box. I tried several ways using jQuery, but none of them worked.

The response I am getting (I can format this differently if necessary):

["<option value='Woodland Hills'>Woodland Hills<\/option>","<option value='none'>none<\/option>","<option value='Los Angeles'>Los Angeles<\/option>","<option value='Laguna Hills'>Laguna Hills<\/option>"]

But how can I put this data as options inside a HTML <select></select> tag?

The code I tried:

<form action="" method="post">
<input id="city" name="city" type="text" onkeyup="getResults(this.value)"/>
<input type="text" id="result" value=""/>
<select id="myselect" name="myselect" ><option selected="selected">blank</option></select>
</form>
</div>

<script>
function getResults(str) {
  $.ajax({
        url:'suggest.html',
        type:'POST',
        data: 'q=' + str,
        dataType: 'json',
        success: function( json ) {
            $('#myselect').append(json);

        }
    });
};

$( '.suggest' ).keyup( function() {
   getResults( $( this ).val() );
} );
</script>

I also tried to use this tutorial on auto-populating select boxes using jQuery and AJAX, but this never did anything except filling my select with “UNDEFINED” for me even though I got the response in the format the tutorial suggested.

<script type="text/javascript" charset="utf-8">
$(function(){
  $("select#city").change(function(){
    $.getJSON("/select.php",{id: $(this).val(), ajax: 'true'}, function(j){
      var options = '';
      for (var i = 0; i < j.length; i++) {
        options += '<option value="' + j[i].optionValue + '">' + j[i].optionDisplay + '</option>';
      }
      $("select#myselect").html(options);
    })
  })
})
</script>
Answers:

Why not just make the server return the names?

["Woodland Hills", "none", "Los Angeles", "Laguna Hills"]

Then create the <option> elements using JavaScript.

$.ajax({
    url:'suggest.html',
    type:'POST',
    data: 'q=' + str,
    dataType: 'json',
    success: function( json ) {
        $.each(json, function(i, value) {
            $('#myselect').append($('<option>').text(value).attr('value', value));
        });
    }
});

Questions:
Answers:

You should do it like this:

function getResults(str) {
  $.ajax({
        url:'suggest.html',
        type:'POST',
        data: 'q=' + str,
        dataType: 'json',
        success: function( json ) {
           $.each(json, function(i, optionHtml){
              $('#myselect').append(optionHtml);
           });
        }
    });
};

Cheers

Questions:
Answers:

Given returned json from your://site.com:

[{text:"Text1", val:"Value1"},
{text:"Text2", val:"Value2"},
{text:"Text3", val:"Value3"}]

Use this:

    $.getJSON("your://site.com", function(json){
            $('#select').empty();
            $('#select').append($('<option>').text("Select"));
            $.each(json, function(i, obj){
                    $('#select').append($('<option>').text(obj.text).attr('value', obj.val));
            });
    });