Taxonomies are generally based either on Categories (hierarhical) or on Tags (non-hierarhical) and can be included in default or custom post types.
Default Taxonomies
WordPress offers four built-in taxonomies out of the box:
– Categories and Navigation menu which are hierarhical.
– Tags and Links are multifaceted.
Custom Taxonomies
Custom Taxonomies can be applied to one or several post types, including posts and can have custom index & archive.
Their URL is:
xxx.com/location/carribean // location is taxonomy
xxx.com/hotel-review/hotel-ocean // hotel-review is custom post type
Like with post types, we need to decide where to put taxonomy – in the plugin or in the theme.
Taxonomies in the Database
Taxonomies are saved in wp_term_taxonomy table in the database.
Taxonomy terms are saved in wp_terms table in the database.
Taxonomies Theme Templates
Here are the options.
taxonomy-{taxonomy}-{slug}.php
taxonomy-{taxonomy}.php
taxonomy.php
Output Custom Taxonomy to a Template
<div class="taxonomies">
<div class="product-type">
<?php echo get_the_term_list($post->ID, 'product-type', 'Type of Product: ', ',', ''); ?>
</div>
<div class="price-range">
<?php echo get_the_term_list($post->ID, 'price', 'Price Range: ', ',', ''); ?>
</div>
<div class="satisfaction">
<?php echo get_the_term_list($post->ID, 'satisfaction', 'Satisfaction: : ', ',', ''); ?>
</div>
</div>