Chosen jQuery plugin : get multiple select values in the order they were clicked

问题

I use Chosen jQuery plugin on a multiple select element.

I want to retrieve and to display the options value in the order they were selected (clicked).

For example, if I click on "Three", "Two" then "One", I should get the values in this order: [3, 2, 1]

I use the 'change' event of Chosen but it gives me the values ordered as they are declared in the DOM. i.e.: [1, 2, 3]

Here is my code snippet:

<select class="chosen" data-order="true" name="multiselect[]" id="multiselect" multiple="true">
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
    <option value="4">Four</option>
    <option value="5">Five</option>
</select>

<div id="result"></div>

<script type="text/javascript" src="jquery-1.11.0.js"></script>
<script type="text/javascript" src="chosen.jquery.min.js"></script>
<script type="text/javascript">
    $(".chosen").chosen({enable_search_threshold: 10}).change(function(event) {
        if(event.target == this) {
            var value = $(this).val();
            $("#result").text(value);
        }
    });
</script>

jsFiddle demo: http://jsfiddle.net/FjET4

回答1:

You are facing a common issue with Chosen. Chosen multiple select UI does not actually handle selection order.

By the way, the following part is not specific to the event:

if(event.target == this)
{
    var value = $(this).val();
    $("#result").text(value);
}

In fact, it does exactly the same thing everytime you select an item. With $(this).val() you are basically just asking Chosen to retrieve an array of the values of the selected elements.

And because Chosen does not handle selection order, it just sends you ["1", "2", "3"].

A method to retrieve the selection order as it appears is to iterate though some children of the Chosen UI. Look:

<!-- Chosen UI container -->
<div class="chosen-container chosen-container-multi ..." id="multiselect_chosen">
    <ul class="chosen-choices">
        <li class="search-choice">
            <span>Three</span>
            <a class="search-choice-close" data-option-array-index="2"></a>
        </li>
        <li class="search-choice">
            <span>Five</span>
            <a class="search-choice-close" data-option-array-index="4"></a>
        </li>
        ....
    </ul>
    ...
</div>

As you can see, there is some interesting stuff in <ul class="chosen-choices"></ul>. The data-option-array-index attribute contains the index of the selected item, relative to the actual <select> DOM element options.

I wrote a small plugin for Chosen that allows you to retrieve the selection order, exactly as it appears, and to force it via an array of ordered values (e.g.: ["3", "2", "1"]).

It is open-source and works for both Chosen jQuery plugin and Prototype plugin.

Demonstration: http://labo.tristan-jahier.fr/chosen_order
Github repository: https://github.com/tristanjahier/chosen-order

回答2:

The Chosen plugin has a "change" event that you can use to keep and update a list with selected items, in the order in which they were selected.

    $("#mnu_chosen").on('change', function(e, params) {
        var selected = params.selected;
        var deselected = params.deselected;
        var selected_keys = $(this).data('selected_keys');
        if (!selected_keys) {
            $(this).data('selected_keys', []);
            selected_keys = $(this).data('selected_keys');
        }
        if (deselected) {
            for (var i = 0; i < selected_keys.length; i++) {
                if (selected_keys[i] == deselected) {
                    selected_keys.splice(i, 1);
                    break;
                }
            }
        }
        if (selected) {
            selected_keys.push(selected);
        }
        //See array "selected_keys"
        //Do something on change...
    });

回答3:

Here's a stand alone function that does the job. I'm using Chosen 1.2.0

var orderBy = ChosenValInSelectedOrder('OrderReportBy');

function ChosenValInSelectedOrder(id) {
    var $chosenOptions = $('#' + id + '_chosen .search-choice-close');
    if ($chosenOptions.length == 0)
        return null;
    var results = [];
    var $options = $('#' + id + ' option');
    $chosenOptions.each(function () {
        var idx = parseInt($(this).attr('data-option-array-index'));
        results.push($options[idx].value); // value from original select
    });
    return results;
}

来源：https://stackoverflow.com/questions/21659224/chosen-jquery-plugin-get-multiple-select-values-in-the-order-they-were-clicked

标签

jquery

jquery-chosen