Wordpress Custom Taxonomy - Volume / Issue - Unique Slug Issue

Question

I have a site that I'm making for a quarterly print magazine. I'm making all of the articles from all issues into Wordpress posts.

Every Article/Post belongs to an Issue and every Issue belongs to a Volume (Standard magazine stuff).

Instead of using Categories to represent a hierarchical relationship between Volume --> Issue I thought it would be better to use a Custom Taxonomy.

So I made a Custom Taxonomy of "Volume".

This is how I registered it in functions.php

function add_custom_taxonomies() {
// Add new "Locations" taxonomy to Posts
register_taxonomy('volume', 'post', array(
    // Hierarchical taxonomy (like categories)
    'hierarchical' => true,
    // This array of options controls the labels displayed in the WordPress Admin UI
    'labels' => array(
        'name' => _x( 'Volumes', 'taxonomy general name' ),
        'singular_name' => _x( 'Volume', 'taxonomy singular name' ),
        'search_items' =>  __( 'Search Issues' ),
        'all_items' => __( 'All Issues' ),
        'parent_item' => __( 'Parent Volume' ),
        'parent_item_colon' => __( 'Parent Volume:' ),
        'edit_item' => __( 'Edit Volume' ),
        'update_item' => __( 'Update Volume' ),
        'add_new_item' => __( 'Add New Volume' ),
        'new_item_name' => __( 'New Volume Name' ),
        'menu_name' => __( 'Volume-Issue' ),
    ),
    // Control the slugs used for this taxonomy
    'rewrite' => array(
        'slug' => 'volume', // This controls the base slug that will display before each term
        'with_front' => true, // Don't display the category base before "/volume/"
        'hierarchical' => true // "
    ),
));

} add_action( 'init', 'add_custom_taxonomies', 0 );

The issue is now that the slug for Taxonomies need to be unique so instead of the urls being very pretty like:

example.com/volume/volume1/issue-2/

i get

example.com/volume/volume-11/issue-1-volume-11/

This seems to be because the slugs "issue-1", "issue-2", "issue-3" and "issue-4" were taken up in the first volume and slugs need to be unique?

It's not the worst problem in the world but I though that since the Taxonomy for Issue is under a Volume which is unique I wouldn't have this problem. However, I do....

Anyway, can anyone suggest a better way to do this? Custom post Types possibly? Though I thought this was the perfect answer, just can't seem to get the URL's and slugs to cooperate.

I'd like to just come out with very pretty and predictable URLS like:

example.com/volume-1/issue-1/ example.com/volume-1/issue-2/ example.com/volume-9/issue-3/

I'd really appreciate the communities insight on this.

Thanks

Mike

Answer 1

There are a lot of ways you can solve this issue. What I'd do if it were me is to make "issue" its own taxonomy.

If issue is its own taxonomy, then the terms can be unique (and things are much less cluttered). An article will then belong to a volume, and also an issue. The trick is to create a hierarchy in the rewrite rules to make issues a part of volumes, and articles a part of both.

Here, I'm going to make your URLS look like this:

• /volume/1/
• /volume/1/issue/2/
• /volume/1/issue/2/article-title/

In your article post type declaration, you'll want to set:

'rewrite' => array( 'slug' => 'volume/%volume%/issue/%issue%' )

In your issue taxonomy declaration, you'll want to set:

'rewrite' => array( 'slug' => 'volume/%volume%/issue' )

Lastly, you'll want to add filters to post_type_link and term_link so the auto-generate links don't contain %volume% and %issue%. Rather than reinvent the wheel, see "How do I append multiple taxonomies to the URL?" (amongst many, many others) on how to do that.

As always when making rewrite changes, be sure to flush your rewrite rules. You can do so by going to Settings->Permalinks and clicking "Save Changes".

Answer 2

Your custom taxonomy try was nice, but I thing you should use another approach. Why not use the hierarchy of posts themselves ? By default, Posts are not hierarchical, but Pages are. It means they can have parents and can be ordered. Look at the hierarchical parameter in register_post_type.

If you create a master Page for each volume, then one sub page in this volume for each Issue, and then one sub sub page for each article within this Issue, you will end up with the correct URLs without any pain. You can even use custom page templates to make the difference between Volumes, Issues and articles and have the example.com/volume-1/ URL displaying the list of this volume issues.