Reset select2 value and show placeholder

问题

How do I set the placeholder on value reset by select2. In my example If locations or grade select boxes are clicked and my select2 has a value than the value of select2 should reset and show the default placeholder. This script is resetting the value but won't show the placeholder

$("#locations, #grade ").change(function() {
   $('#e6').select2('data', {
     placeholder: "Studiengang wählen",
     id: null,
     text: ''
   });
});

$("#e6").select2({
   placeholder: "Studiengang wählen",
   width: 'resolve',
   id: function(e) {
     return e.subject;
   },
   minimumInputLength: 2,
   ajax: {
     url: "index.php?option=com_unis&task=search.locator&tmpl=component&<?php echo JSession::getFormToken() ?>=1",
     dataType: 'json',
     data: function(term, page) {
       return {
         q: term, // search term
         g: $('#grade option:selected').val(),
         o: $('#locations option:selected').val()
       };
     },
     results: function(data, page) {
       return {
         results: data
       };
     }
   },
   formatResult: subjectFormatResult,
   formatSelection: subjectFormatSelection,
   dropdownCssClass: "bigdrop",
   escapeMarkup: function(m) {
     return m;
   }
});

回答1:

You must define the select2 as

$("#customers_select").select2({
    placeholder: "Select a customer",
    initSelection: function(element, callback) {                   
    }
});

To reset the select2

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

回答2:

Select2 has changed their API:

Select2: The select2("val") method has been deprecated and will be removed in later Select2 versions. Use $element.val() instead.

The best way to do this now is:

$('#your_select_input').val('');

Edit: December 2016 Comments suggest that the below is the updated way to do this:

$('#your_select_input').val([]);

回答3:

The accepted answer does not work in my case. I'm trying this, and it's working:

Define select2:

$("#customers_select").select2({
    placeholder: "Select a State",
    allowClear: true
});

$("#customers_select").select2({
    placeholder: "Select a State"
});

To reset:

$("#customers_select").val('').trigger('change')

$("#customers_select").empty().trigger('change')

回答4:

The only thing can work for me is:

$('select2element').val(null).trigger("change")

I'm using version 4.0.3

Reference

According to Select2 Documentation

回答5:

Select2 uses a specific CSS class, so an easy way to reset it is:

$('.select2-container').select2('val', '');

And you have the advantage of if you have multiple Select2 at the same form, all them will be reseted with this single command.

回答6:

Use this :

$('.select').val([]).trigger('change');

回答7:

TO REMOVE SELECTED VALUE

$('#employee_id').select2('val','');

TO CLEAR OPTION VALUES

$('#employee_id').html('');

回答8:

I know this is kind of an old question, but this works for the select2 version 4.0

 $('#select2-element').val('').trigger('change');

$('#select2-element').val('').trigger('change.select2');

if you have change events bound to it

回答9:

With Select2 version 4.0.9 this works for me:

$( "#myselect2" ).val('').trigger('change');

回答10:

Use following to configure select2

    $('#selectelementid').select2({
        placeholder: "Please select an agent",
        allowClear: true // This is for clear get the clear button if wanted 
    });

And to clear select input programmatically

    $("#selectelementid").val("").trigger("change");
    $("#selectelementid").trigger("change");

回答11:

This is the correct way:

 $("#customers_select").val('').trigger('change');

I am using the latest release of Select2.

回答12:

Firstly you must define select2 like this:

$('#id').select2({
    placeholder: "Select groups...",
    allowClear: true,
    width: '100%',
})

To reset select2, simply you may use the following code block:

$("#id > option").removeAttr("selected");
$("#id").trigger("change");

回答13:

For users loading remote data, this will reset the select2 to the placeholder without firing off ajax. Works with v4.0.3:

$("#lstProducts").val("").trigger("change.select2");

回答14:

I tried the above solutions but it didn't work for me.

This is kind of hack, where you do not have to trigger change.

$("select").select2('destroy').val("").select2();

$("select").each(function () { //added a each loop here
        $(this).select2('destroy').val("").select2();
});

回答15:

You can clear te selection by

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

But it wont turn you back to your placeholder.

So its a half solution

回答16:

So, to reset the form some of you will have a reset button. Add the following code inside the script tag

$('.your_btn_class').click(function(){
    $('#select_field_id').val([]);
    $("#select_field_id").select2({
    placeholder: "this is a placeholder",
    });
});

Or just to empty select field without keeping a placeholder:

$('.your_btn_class').click(function(){
    $('#select_field_id').val([]);
 });

回答17:

Following the recommended way of doing it. Found in the documentation https://select2.github.io/options.html#my-first-option-is-being-displayed-instead-of-my-placeholder (this seems to be a fairly common issue):

When this happens it usually means that you do not have a blank <option></option> as the first option in your <select>.

as in:

<select>
   <option></option>
   <option value="foo">your option 1</option>
   <option value="bar">your option 2</option>
   <option value="etc">...</option>
</select>

回答18:

I was also having this problem and it stems from val(null).trigger("change"); throwing a No select2/compat/inputData error before the placeholder gets reset. I solved it by catching the error and setting the placeholder directly (along with a width). Note: If you have more than one you will need to catch each one.

try{
    $("#sel_item_ID").select2().val(null).trigger("change");
}catch(err){
    console.debug(err)
}
try{
    $("#sel_location_ID").select2().val(null).trigger("change");
}catch(err){
    console.debug(err)
}
$('.select2-search__field')[0].placeholder='All Items';
$('.select2-search__field')[1].placeholder='All Locations';
$('.select2-search__field').width(173);

I'm running Select2 4.0.3

回答19:

For the place holder

$("#stateID").select2({
    placeholder: "Select a State"
});

To reset a select 2

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

Hope this helps

回答20:

I have tried above solutions but none worked with version 4x.

What i want to achieve is: clear all options but don't touch the placeholder. This code works for me.

selector.find('option:not(:first)').remove().trigger('change');

回答21:

Using select2 version 3.2 this worked for me:

$('#select2').select2("data", "");

Didn't need to implement initSelection

回答22:

as of v.4.0.x...

to clear the values, but also restore the placeholder use...

.html('<option></option>');  // defaults to placeholder

if it's empty, it will select the first option item instead which may not be what you want

.html(''); // defaults to whatever item is first

frankly...Select2 is such a pain in the butt, it amazes me it hasn't been replaced.

回答23:

Before you clear the value using this $("#customers_select").select2("val", ""); Try setting focus to any other control on reset click.

This will show the placeholder again.

回答24:

The DOM interface, already keeps track of the initial state...

So doing the following is enough:

$("#reset").on("click", function () {
    $('#my_select option').prop('selected', function() {
        return this.defaultSelected;
    });
});

回答25:

Well whenever I did

$('myselectdropdown').select2('val', '').trigger('change');

I started getting some kind of lag after some three to four triggers. I suppose there's a memory leak. Its not within my code because if I do remove the this line, my app is lag free.

Since I have allowClear options set to true, I went with

$('.select2-selection__clear').trigger('mousedown');

This can be followed by a $('myselectdropdown').select2('close'); event trigger on the select2 dom element in case you wanna close the open suggestion drop down.

回答26:

One [very] hacky way to do it (I saw it work for version 4.0.3):

var selection = $("#DelegateId").data("select2").selection;
var evt = document.createEvent("UIEvents");
selection._handleClear(evt);
selection.trigger("toggle", {});

allowClear must be set to true
an empty option must exist in the select element

回答27:

After trying the first 10 solutions here and failing, I found this solution to work (see "nilov commented on Apr 7 • edited" comment down the page):

(function ($) {
   $.fn.refreshDataSelect2 = function (data) {
       this.select2('data', data);

       // Update options
       var $select = $(this[0]);
       var options = data.map(function(item) {
           return '<option value="' + item.id + '">' + item.text + '</option>';
       });
       $select.html(options.join('')).change();
   };
})(jQuery);

The change is then made:

var data = [{ id: 1, text: 'some value' }];
$('.js-some-field').refreshDataSelect2(data);

(The author originally showed var $select = $(this[1]);, which a commenter corrected to var $select = $(this[0]);, which I show above.)

回答28:

My solution is:

$el.off('select2:unselect')
$el.on('select2:unselect', function (event) {
    var $option = $('<option value="" selected></option>');
    var $selected = $(event.target);

    $selected.find('option:selected')
             .remove()
             .end()
             .append($option)
             .trigger('change');
    });

回答29:

$('myselectdropdown').select2('val', '0')

where 0 is your first value of the dropdown

回答30:

Use this code into your js file

$('#id').val('1');
$('#id').trigger('change');

来源：https://stackoverflow.com/questions/17957040/reset-select2-value-and-show-placeholder

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