Clear dropdown using jQuery Select2

问题

I'm trying to programmatically clear a drop down using the fantastic Select2 library. The drop down is dynamically filled with a remote ajax call using the Select2 query option.

HTML:

<input id="remote" type="hidden" data-placeholder="Choose Something" />

Javascript:

        var $remote = $('#remote');

        $remote.select2({
            allowClear: true,
            minimumInputLength: 2,
            query: function(options){
                $.ajax({
                    dataType: 'json',
                    url: myURL + options.term,
                    error: function(jqXHR, textStatus, errorThrown){
                        smoke.alert(textStatus + ": server returned error on parsing arguments starting with " + options.term);
                    },
                    success: function(data, textStatus, jqXHR){
                        var results = [];
                        for(var i = 0; i < data.length; ++i){
                            results.push({id: data[i].id, text: data[i].name});
                        }

                        options.callback({results: results, more: false});
                    }
                });
            }
        });

Unfortunately, the call to $remove.select2('val', '') throws the following exception:

 Uncaught Error: cannot call val() if initSelection() is not defined

I've tried setting the attr, setting the val, text and the Select2 specific data function. Can't seem to make the guy clear and work in a radio button like manner. Anyone got suggestions?

回答1:

This works for me:

 $remote.select2('data', {id: null, text: null})

It also works with jQuery validate when you clear it that way.

-- edit 2013-04-09

At the time of writing this response, it was the only way. With recent patches, a proper and better way is now available.

$remote.select2('data', null)

回答2:

In case of Select2 Version 4+

it has changed syntax and you need to write like this:

// clear all option
$('#select_with_blank_data').html('').select2({data: [{id: '', text: ''}]});

// clear and add new option
$("#select_with_data").html('').select2({data: [
 {id: '', text: ''},
 {id: '1', text: 'Facebook'},
 {id: '2', text: 'Youtube'},
 {id: '3', text: 'Instagram'},
 {id: '4', text: 'Pinterest'}]});

回答3:

This is the proper one, select2 will clear the selected value and show the placeholder back .

$remote.select2('data', null)

回答4:

For select2 version 4 easily use this:

$('#remote').empty();

After populating select element with ajax call, you may need this line of code in the success section to update the content:

  success: function(data, textStatus, jqXHR){
  $('#remote').change();
                }

回答5:

Using select2 version 4 you can use this short notation:

$('#remote').html('').select2({data: {id:null, text: null}});

This passes a json array with null id and text to the select2 on creation but first, with .html('') empties the previously stored results.

回答6:

Method proposed @Lelio Faieta is working for me, but because i use bootstrap theme, it remove all bootstrap settings for select2. So I used following code:

$("#remote option").remove();

回答7:

You should use this one :

   $('#remote').val(null).trigger("change");

回答8:

I'm a little late, but this is what's working in the last version (4.0.3):

$('#select_id').val('').trigger('change');

回答9:

These both work for me to clear the dropdown:

.select2('data', null)
.select2('val', null)

But important note: value doesn't get reset, .val() will return the first option even if it's not selected. I'm using Select2 3.5.3

回答10:

I found the answer (compliments to user780178) I was looking for in this other question:

Reset select2 value and show placeholdler

$("#customers_select").select2("val", "");

回答11:

From >4.0 in order to really clean the select2 you need to do the following:

$remote.select2.val('');
$remote.select2.html('');
selectedValues = []; // if you have some variable where you store the values
$remote.select2.trigger("change");

Please note that we select the select2 based on the initial question. In your case most probably you will select the select2 in a different way.

Hope it helps.

回答12:

This solved my problem in version 3.5.2.

$remote.empty().append(new Option()).trigger('change');

According to this issue you need an empty option inside select tag for the placeholder to show up.

回答13:

Since none of them all worked for me (select2 4.0.3) is went the std select way.

for(var i = selectbox.options.length - 1 ; i >= 0 ; i--)
    selectbox.remove(i);

回答14:

You can use this or refer further this https://select2.org/programmatic-control/add-select-clear-items

$('#mySelect2').val(null).trigger('change');

回答15:

This is how I do:

$('#my_input').select2('destroy').val('').select2();

来源：https://stackoverflow.com/questions/13240047/clear-dropdown-using-jquery-select2

标签

javascript

jquery

jquery-select2