Gets all term data from database by term field and data.
Description
Warning: $value is not escaped for ‘name’ $field. You must do it yourself, if required.
The default $field is ‘id’, therefore it is possible to also use null for field, but not recommended that you do so.
If $value does not exist, the return value will be false. If $taxonomy exists and $field and $value combinations exist, the term will be returned.
This function will always return the first term that matches the $field
– $value
–$taxonomy
combination specified in the parameters. If your query is likely to match more than one term (as is likely to be the case when $field
is ‘name’, for example), consider using get_terms() instead; that way, you will get all matching terms, and can provide your own logic for deciding which one was intended.
See also
- sanitize_term_field(): The $context param lists the available values for get_term_by() $filter param.
Parameters
$field
stringrequired- Either
'slug'
,'name'
,'term_id'
(or'id'
,'ID'
), or'term_taxonomy_id'
. $value
string|intrequired- Search for this term value.
$taxonomy
stringoptional- Taxonomy name. Optional, if
$field
is'term_taxonomy_id'
.Default:
''
$output
stringoptional- The required return type. One of OBJECT, ARRAY_A, or ARRAY_N, which correspond to a WP_Term object, an associative array, or a numeric array, respectively.
Default:
OBJECT
$filter
stringoptional- How to sanitize term fields. Default
'raw'
.Default:
'raw'
Source
function get_term_by( $field, $value, $taxonomy = '', $output = OBJECT, $filter = 'raw' ) {
// 'term_taxonomy_id' lookups don't require taxonomy checks.
if ( 'term_taxonomy_id' !== $field && ! taxonomy_exists( $taxonomy ) ) {
return false;
}
// No need to perform a query for empty 'slug' or 'name'.
if ( 'slug' === $field || 'name' === $field ) {
$value = (string) $value;
if ( 0 === strlen( $value ) ) {
return false;
}
}
if ( 'id' === $field || 'ID' === $field || 'term_id' === $field ) {
$term = get_term( (int) $value, $taxonomy, $output, $filter );
if ( is_wp_error( $term ) || null === $term ) {
$term = false;
}
return $term;
}
$args = array(
'get' => 'all',
'number' => 1,
'taxonomy' => $taxonomy,
'update_term_meta_cache' => false,
'orderby' => 'none',
'suppress_filter' => true,
);
switch ( $field ) {
case 'slug':
$args['slug'] = $value;
break;
case 'name':
$args['name'] = $value;
break;
case 'term_taxonomy_id':
$args['term_taxonomy_id'] = $value;
unset( $args['taxonomy'] );
break;
default:
return false;
}
$terms = get_terms( $args );
if ( is_wp_error( $terms ) || empty( $terms ) ) {
return false;
}
$term = array_shift( $terms );
// In the case of 'term_taxonomy_id', override the provided `$taxonomy` with whatever we find in the DB.
if ( 'term_taxonomy_id' === $field ) {
$taxonomy = $term->taxonomy;
}
return get_term( $term, $taxonomy, $output, $filter );
}
Examples
Examples to get terms by name and taxonomy type (taxonomy_name as category, post_tag or custom taxonomy).
By id (term_id, not post_id):
Example of retrieving a category by it’s name:
Output:
get_term_by() returns a single WP_Term object. Because of core changes from v4.1 – 4.3, it’s now possible for multiple terms to match the supplied name or slug parameters. The WP_Term Object returned will be the first matching term found by mySQL, there is no indication that other matching terms may exist. If there is any possibility of multiple terms having the same name or slug in your application, you should use get_terms() instead of get_term_by() .
If you are using a custom taxonomy, this might not work unless you add the third parameter, namely the taxonomy name:
My custom taxonomy is
wpdocs_playlist
.