如何修复WordPress自定义页面中的“TypeError：$（...）。chained is not function”错误？

Question

I create a custom WordPress page via widget where I want to active a widget using this code

jQuery(document).ready(function($) {
    /* For $.chained.js */
    $("#series").chained("#mark");
    $("#model").chained("#series");
    $("#engine").chained("#series, #model");

    return;
    /* Show button after each pulldown has a value. */
    $("#engine").bind("change", function(event) {
        if ("" != $("option:selected", this).val() && "" != $("option:selected", $("#model")).val()) {
            $("#button").fadeIn();
        } else {
            $("#button").hide();          
        }
    })
});

When I activated the widget, that code can work fine but if I inactivated the widget that code show error TypeError: $(....).chained is not function. So how to fix this ? Thank you ..

Answer 1

This happens because the "Chained Selects" plugin source is not included:

function enqueue_stuff(){
    wp_enqueue_script('chainedjs', 'https://raw.githubusercontent.com/tuupola/jquery_chained/master/jquery.chained.remote.min.js', array('jquery'), false, true);    
}
add_action('wp_enqueue_scripts', 'enqueue_stuff');