How do I retrieve multiple selected values from a Laravel Form::select element with jQuery?

Below is an explanation and solution for retrieving the selected values from a multiple‑select field.

What’s Happening

1. Error Explanation:
   The error

   Uncaught TypeError: $(...).multiselect is not a function
   

   indicates that the jQuery plugin method “multiselect” isn’t defined. This often happens if the script for that plugin hasn’t been loaded or you’re using a different plugin.

2. Laravel Collective Setup:
   Your form uses Laravel Collective’s Form::select, but you haven’t set an id. This means that doing something like $('#itemStatus') won’t fetch your select element unless you set an id attribute.

How to Fix

You have two options depending on your intended plugin/behavior:

Option 1: Use the Built‑in jQuery Method

If your goal is simply to get the currently selected values, you can use the native jQuery .val() method. Make sure you assign an id to your select element:

Blade Template (setting the id):

PHPCopied
<div class="flex-grow-1 w-100">
    {!! Form::select(
        'itemStatus[]',
        $itemStatusItems,
        null,
        [
            'id' => 'itemStatus',
            'class' => 'form-control selectpicker',
            'multiple' => true,
            'data-none-selected-text' => trans('Item Status'),
        ],
        $itemStatusSelected
    ) !!}
</div>

JavaScript:

JAVASCRIPTCopied
function showtItems(event) {
    // Get selected values using .val()
    let itemStatus = $('#itemStatus').val();

    $.ajax({
        url: '{{ route('getData', $point->id ) }}',
        type: 'post',
        data: {itemStatus: itemStatus},
        success: function (data) {
            // Handle success
            console.log(data);
        }
    }).done().fail(function (data) {
        // Handle error
        console.error(data);
    });

    event.stopPropagation();
    return false;
}

Option 2: Use a Specific Multiselect Plugin

If you intend to use a multiselect plugin (for example, the Bootstrap Multiselect), you need to:

• Ensure you include its JavaScript and CSS files.
• Initialize the plugin on your select element.

Include the Plugin (in your layout or view):

HTMLCopied
<!-- Include plugin CSS -->
<link rel="stylesheet" href="/path/to/bootstrap-multiselect.css">

<!-- Include plugin JS after jQuery and Bootstrap JS -->
<script src="/path/to/bootstrap-multiselect.js"></script>

Blade Template (set id):

PHPCopied
<div class="flex-grow-1 w-100">
    {!! Form::select(
        'itemStatus[]',
        $itemStatusItems,
        null,
        [
            'id' => 'itemStatus',
            'class' => 'form-control selectpicker',
            'multiple' => true,
            'data-none-selected-text' => trans('Item Status'),
        ],
        $itemStatusSelected
    ) !!}
</div>

Initialize and Use the Plugin in JavaScript:

JAVASCRIPTCopied
$(document).ready(function(){
    // Initialize Bootstrap Multiselect
    $('#itemStatus').multiselect();

    function showtItems(event) {
        // Retrieve the selected options from the plugin
        let itemStatus = $('#itemStatus').val();  // or use plugin's API if needed

        $.ajax({
            url: '{{ route('getData', $point->id ) }}',
            type: 'post',
            data: {itemStatus: itemStatus},
            success: function (data) {
                console.log(data);
            }
        }).done().fail(function (data) {
            console.error(data);
        });

        event.stopPropagation();
        return false;
    }

    // Bind the function to an event if necessary
    $('#someButton').on('click', showtItems);
});

Summary

• Is it valid to call .multiselect()?
  Not unless you have included and initialized a plugin that defines that method.

• Simple Retrieval:
  For a multiple‑select field, use $('#itemStatus').val() which returns an array of selected values.

• Using a Plugin:
  Include the necessary plugin files and initialize the select element with that plugin; then use its methods or simply rely on .val().

Choose the method that best fits your requirements.