Wordpress can't access globals and functions.php category edit page

Question

i got my registered sidebars listing function in functions.php everything works perfect on post options page (wp-admin/post.php) i can get all the registered sidebars via my function.

but in the category edit page (wp-admin/edit-tags.php) , i can't even access the global variable $wp_registered_sidebars , not mentioning about the function itself.

here is the function

function sidebars_list(){

global $wp_registered_sidebars;
$sidebar = array();

if (!empty($wp_registered_sidebars)):
  foreach ($wp_registered_sidebars as $key => $access):
      $sidebar[$key] = $access['name'];
  endforeach;
endif;

var_dump($sidebar);

return $sidebar;
}

as i said it works perfect on editing post and pages at the backend (frontend as well)

i tried to add_action it , no luck. can't even access the global variable in category edit page.

global $wp_registered_sidebars;
var_dump($wp_registered_sidebars);

returns empty array. but when i var_dump inside the function it returns as expected. what's wrong ?

Answer 1

As you said that the global variable value not found. I assume that your variable got overwritten the value with empty array.

I suggest you to change the variable name and retry with var_dump the variable.

global $wp_registered_sidebars_custom;
var_dump($wp_registered_sidebars_custom);

Answer 2

After wasting a lot of time for searching this and thought out this solution. Accessing through a category page is earlier before sidebar values are loaded. So You can make a work around by placing a placeholder div in that place and load the values in the dropdown or checkbox using Ajax & jQuery after the page is loaded. that would work for you.

Paste the following code in functions.php of your theme

// Call Actio to modify form on Add New Category
add_action( 'category_add_form_fields', 'edit_category_fields');

// Call Action to modify form on Edit Category
add_action( 'category_edit_form_fields', 'edit_category_fields');


function edit_category_fields($tag, $taxonomy)
{
    // Get the Current Value if any
    $leftsidebar_to_show = get_term_meta( $tag->term_id, 'leftsidebar_to_show', true);
    ?>
    <tr class="form-field">
        <th scope="row" valign="top"><label for="leftsidebar_to_show">Select Left Sidebar to Show</label></th>
        <td>
            <div id="leftsidebar_to_show_wrap">
                <select name="leftsidebar_to_show" id="leftsidebar_to_show">

                </select>
            </div>
            <!-- Store the current value as hidden input in order to Get Selected Option in jQuery -->
            <input type="hidden"  id="leftsidebar_to_show_val" value="<?php echo $leftsidebar_to_show; ?>" />

            <!-- Category ID as hidden Input -->
            <input type="hidden" name="term_id_val" value="<?php echo $tag->term_id; ?>" />
        </td>
    </tr>

    <?php
}

// Call Actio to Save Values on Add New Category
add_action( 'edited_category', 'save_category', 10, 2);

// Call Action to Save Values on Edit Category
add_action( 'create_category', 'save_category', 10, 2);

function save_category(){  
    update_term_meta( $_POST['term_id_val'], 'leftsidebar_to_show', $_POST['leftsidebar_to_show']);
}

// Function to enqueue Javascript file in admin
function my_enqueue($hook) {
    wp_enqueue_script( 'my_custom_script', get_template_directory_uri() . '/js/sidebars.js' );
}
add_action( 'admin_enqueue_scripts', 'my_enqueue' );

// Action Function to get Sidebars through Ajax Call
function prefix_ajax_get_sidebars() {
    $sidebarval = $_REQUEST['sidebarval'];
    $sidebarid = $_REQUEST['sidebarid'];
    $string = '<select id="'.$sidebarid.'" name="'.$sidebarid.'">';
    foreach ( $GLOBALS['wp_registered_sidebars'] as $sidebar ) {
        if($sidebarval == $sidebar['id']){
            $selected = ' selected';
        }else{
            $selected = '';
        }
        $string .= '<option value="'.$sidebar['id'].'"'.$selected.'>'.$sidebar['name'].'</option>';
    }
    $string .= '</select>';
    echo $string;
    die();
}
add_action( 'wp_ajax_get_sidebars', 'prefix_ajax_get_sidebars' );
add_action('wp_ajax_nopriv_get_sidebars', 'prefix_ajax_get_sidebars');

Create a file named sidebars.js and Paste the following code

(function ($) {
    "use strict";
    $(document).ready(function(){
        var leftsidebar_to_show_val = $('#leftsidebar_to_show_val').val();
        $.post(
            ajaxurl,
            {
                'action': 'get_sidebars',
                'sidebarval':   leftsidebar_to_show_val,
                'sidebarid' : 'leftsidebar_to_show'
            },
            function(response){
                $('#leftsidebar_to_show_wrap').html(response);
        });

    });


})(jQuery);

And move the above created file to js folder of your theme. Now you can see the sidebars listed as dropdown in the Add & Edit Category Forms.

Hope this is clear.

Thanks!