Trying to sort and display categories(not posts) by custom field: 'order'

Question

I'm a WordPress rookie. I've added a custom field to my "Category" taxonomy. The custom field is "custom_order" and its purpose is to hold a number so that my categories can be sorted and displayed in the order I choose.

My problem is that I can't get them to sort; I can display the categories, and 'echo' each category's "custom_order" number, but I must be missing something when it comes to accessing and sorting the meta_value.

Not sure if I'm going about this the right way either.

Here is my code to add the field to the 'New Category' page:

<?php
function taxonomy_add_new_meta_field() 
{ ?>
<div class="form-field">
    <label for="term_meta[custom_order]">Order</label>
    <input type="number" name="term_meta[custom_order]" id="term_meta[custom_order]" value="">
    <p class="description">Enter an order number for organizational purposes</p>
</div>
<?php
}

add_action( 'category_add_form_fields', 'taxonomy_add_new_meta_field', 10, 2 );
?>

Here is my code to add the field to the 'Edit Category' page:

<?php
function taxonomy_edit_meta_field($term) {

$t_id = $term->term_id;

$term_meta = get_option( "taxonomy_$t_id" ); ?>
<tr class="form-field">
    <th scope="row" valign="top"><label for="term_meta[custom_order]">Order</label></th>
    <td>
        <input type="number" name="term_meta[custom_order]" id="term_meta[custom_order]" value="<?php                 echo esc_attr( $term_meta['custom_order'] ) ? esc_attr(     $term_meta['custom_order'] ) : ''; ?>">
        <p class="description">Enter an order number for organizational purposes</p>
    </td>
</tr>
<?php
}
add_action( 'category_edit_form_fields', 'taxonomy_edit_meta_field', 10, 2);
?>

Here is my code to save the contents of the field:

<?php

function save_taxonomy_custom_meta( $term_id ) {
if ( isset( $_POST['term_meta'] ) ) {
    $t_id = $term_id;
    $term_meta = get_option( "taxonomy_$t_id" );
    $cat_keys = array_keys( $_POST['term_meta'] );
    foreach ( $cat_keys as $key) {
        if ( isset ( $_POST['term_meta'][$key] ) ) {
            $term_meta[$key] = $_POST['term_meta'][$key];
                    }
                }
                update_option( "taxonomy_$t_id", $term_meta );
        }
}

add_action( 'edited_category', 'save_taxonomy_custom_meta', 10, 2 );
add_action( 'create_category', 'save_taxonomy_custom_meta', 10, 2 );

The above snippets of code I got from this website:

http://pippinsplugins.com/adding-custom-meta-fields-to-taxonomies/

Last but not least here is my attempt to sort my categories based on this field:

$args = array(
'parent' => $category->cat_ID,
'hide_empty'=>0,
'exclude'=>'1',
'meta_key'=>'custom_order',
'orderby'=>'meta_value_num',
'order'=>'ASC'
);
$subcategories = get_categories($args);

I then iterate through the $subcategories array with a foreach() loop. I thought I had it working until I added a third sub-category; I now see that it puts 'custom_order' 1 first, 'custom_order' 3 second, and 'custom_order' 2 third.

Can anybody lend me a hand?

Answer 1

I would edit the SQL database directly, changing category IDs based on my desired order. Then I would use 'orderby'=>'id' to sort.

You could also add an integer to the slug (i.e., 1-fish, 2-chips, 3-dips, etc.) and order by slug, but those would appear on the front end.

Answer 2

Some example workarounds (may need a bit modification):

1st way:

$arguments= array('parent' => $categoryID);
$categories = get_categories( $arguments );

$subcategories=array();
foreach($categories as $each=>$value){
    $subcategories[$value->CUSTOM_FIELD_NAME] = $value;
}

asort($subcategories);
foreach($subcategories as $each=>$value){
    //do what you want here
}   

2nd way:

$args = array(
    'parent' => $category->cat_ID,
    'hide_empty'=>0,
    'exclude'=>'1',
    'meta_key'=>'custom_order',
    'orderby'=>'meta_value_num',
    'order'=>'ASC'
);
$subcategories = get_categories($args);