问题

I am converting an <input type=\"hidden\"> to a select2 dropdown and feeding it data through the query method

$(\'#inputhidden\').select2({
    query: function( query ) {
        query.callback( data ); // the data is in the format select2 expects and all works well..
    );
});

The problem is i needed to hack the select2 UI and position two buttons on top of the search bar that, when clicked, will perform ajax calls and will have to update the select2 content.

$\"enter$

Now, I need those updates to occur without rebuilding the select2 entirely but rather just refreshing the items on the dropdown. I cannot find a way to pass a new set of data to an already created select2 control, is that possible ?

回答1:

select2 v3.x

If you have local array with options (received by ajax call), i think you should use data parameter as function returning results for select box:

var pills = [{id:0, text: "red"}, {id:1, text: "blue"}]; 

$('#selectpill').select2({
    placeholder: "Select a pill",
    data: function() { return {results: pills}; }
});

$('#uppercase').click(function() {
    $.each(pills, function(idx, val) {
        pills[idx].text = val.text.toUpperCase();
    });
});
$('#newresults').click(function() {
    pills = [{id:0, text: "white"}, {id:1, text: "black"}];
});

FIDDLE: http://jsfiddle.net/RVnfn/576/

In case if you customize select2 interface with buttons, just call updateResults (this method not allowed to call from outsite of select2 object but you can add it to allowedMethods array in select2 if you need to) method after updateting data array(pills in example).

select2 v4: custom data adapter

Custom data adapter with additional updateOptions (its unclear why original ArrayAdapter lacks this functionality) method can be used to dynamically update options list (all options in this example):

$.fn.select2.amd.define('select2/data/customAdapter',
    ['select2/data/array', 'select2/utils'],
    function (ArrayAdapter, Utils) {
        function CustomDataAdapter ($element, options) {
            CustomDataAdapter.__super__.constructor.call(this, $element, options);
        }
        Utils.Extend(CustomDataAdapter, ArrayAdapter);
        CustomDataAdapter.prototype.updateOptions = function (data) {
            this.$element.find('option').remove(); // remove all options
            this.addOptions(this.convertToOptions(data));
        }        
        return CustomDataAdapter;
    }
);

var customAdapter = $.fn.select2.amd.require('select2/data/customAdapter');

var sel = $('select').select2({
    dataAdapter: customAdapter,
    data: pills
});

$('#uppercase').click(function() {
    $.each(pills, function(idx, val) {
        pills[idx].text = val.text.toUpperCase();
    });
    sel.data('select2').dataAdapter.updateOptions(pills);
});

FIDDLE: https://jsfiddle.net/xu48n36c/1/

select2 v4: ajax transport function

in v4 you can define custom transport method that can work with local data array (thx @Caleb_Kiage for example, i've played with it without succes)

docs: https://select2.github.io/options.html#can-an-ajax-plugin-other-than-jqueryajax-be-used

Select2 uses the transport method defined in ajax.transport to send requests to your API. By default, this transport method is jQuery.ajax but this can be changed.

$('select').select2({
    ajax: {
        transport: function(params, success, failure) {
            var items = pills;
            // fitering if params.data.q available
            if (params.data && params.data.q) {
                items = items.filter(function(item) {
                    return new RegExp(params.data.q).test(item.text);
                });
            }
            var promise = new Promise(function(resolve, reject) {
                resolve({results: items});
            });
            promise.then(success);
            promise.catch(failure);
        }
    }
});

BUT with this method you need to change ids of options if text of option in array changes - internal select2 dom option element list did not modified. If id of option in array stay same - previous saved option will be displayed instead of updated from array! That is not problem if array modified only by adding new items to it - ok for most common cases.

FIDDLE: https://jsfiddle.net/xu48n36c/3/

回答2:

I think it suffices to hand the data over directly:

$("#inputhidden").select2("data", data, true);

Note that the second parameter seems to indicate that a refresh is desired.

Thanks to @Bergi for help with this.

If that doesn't automatically update you could either try calling it's updateResults method directly.

$("#inputhidden").select2("updateResults");

Or trigger it indirectly by sending a trigger to the "input.select2-input" like so:

var search = $("#inputhidden input.select2-input");
search.trigger("input");

回答3:

Using Select2 4.0 with Meteor you can do something like this:

Template.TemplateName.rendered = ->

  $("#select2-el").select2({
    data  : Session.get("select2Data")
  })

  @autorun ->

    # Clear the existing list options. 
    $("#select2-el").select2().empty()

    # Re-create with new options.
    $("#select2-el").select2({
      data  : Session.get("select2Data")
    })

What's happening:

When Template is rendered...
Init a select2 control with data from Session.
@autorun (this.autorun) function runs every time the value of Session.get("select2Data") changes.
Whenever Session changes, clear existing select2 options and re-create with new data.

This works for any reactive data source - such as a Collection.find().fetch() - not just Session.get().

NOTE: as of Select2 version 4.0 you must remove existing options before adding new onces. See this GitHub Issue for details. There is no method to 'update the options' without clearing the existing ones.

The above is coffeescript. Very similar for Javascript.

回答4:

I solved this issue by using the ajax option and specifying a custom transport function.

see this fiddle Select2 dynamic options demo

Here is the relevant js to get this to work.

var $items = [];

let options = {
ajax: {
    transport: function(params, success, failure) {
    let items = $items;

    if (params.data && params.data.q) {
        items = items.filter(function(item) {
        return new RegExp(params.data.q).test(item.text);
        });
    }

    let promise = new Promise(function(resolve, reject) {
        resolve({
        results: items
        });
    });

    promise.then(success);
    promise.catch(failure);
    }
},
placeholder: 'Select item'
};

$('select').select2(options);

let count = $items.length + 1;

$('button').on('click', function() {
$items.push({
    id: count,
    text: 'Item' + count
});
count++;
});

回答5:

Try this one:

var data = [{id: 1, text: 'First'}, {id: 2, text: 'Second'}, {...}];
$('select[name="my_select"]').empty().select2({
    data: data
});

回答6:

var selBoxObj = $('#selectpill');
selBoxObj.trigger("change.select2");

回答7:

As best I can tell, it is not possible to update the select2 options without refreshing the entire list or entering some search text and using a query function.

What are those buttons supposed to do? If they are used to determine the select options, why not put them outside of the select box, and have them programmatically set the select box data and then open it? I don't understand why you would want to put them on top of the search box. If the user is not supposed to search, you can use the minimumResultsForSearch option to hide the search feature.

Edit: How about this...

HTML:

<input type="hidden" id="select2" class="select" />

Javascript

var data = [{id: 0, text: "Zero"}],
    select = $('#select2');

select.select2({
  query: function(query) {
    query.callback({results: data});
  },
  width: '150px'
});

console.log('Opening select2...');
select.select2('open');

setTimeout(function() {
  console.log('Updating data...');
  data = [{id: 1, text: 'One'}];
}, 1500);

setTimeout(function() {
  console.log('Fake keyup-change...');
  select.data().select2.search.trigger('keyup-change');
}, 3000);

Example: Plunker

Edit 2: That will at least get it to update the list, however there is still some weirdness if you have entered search text before triggering the keyup-change event.

回答8:

For Select2 4.X

var instance = $('#select2Container').data('select2');
var searchVal = instance.dropdown.$search.val();
instance.trigger('query', {term:searchVal});

来源：https://stackoverflow.com/questions/16480910/update-select2-data-without-rebuilding-the-control

标签

jquery

jquery-select2

Update select2 data without rebuilding the control

问题