get_term_by( string $field, string|int $value, string $taxonomy = '', string $output = OBJECT, string $filter = 'raw' )
Get 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
-
(Required) Either 'slug', 'name', 'id' (term_id), or 'term_taxonomy_id'
- $value
-
(Required) Search for this term value
- $taxonomy
-
(Optional) Taxonomy name. Optional, if
$field
is 'term_taxonomy_id'.Default value: ''
- $output
-
(Optional) 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 value: OBJECT
- $filter
-
(Optional) default is raw or no ClassicPress defined filter will applied.
Default value: 'raw'
Return
(WP_Term|array|false) WP_Term instance (or array) on success. Will return false if $taxonomy
does not exist or $term
was not found.
Source
File: wp-includes/taxonomy.php
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 || '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 );
}
Changelog
Version | Description |
---|---|
WP-4.4.0 | $taxonomy is optional if $field is 'term_taxonomy_id'. Converted to return a WP_Term object if $output is OBJECT . |
WP-2.3.0 | Introduced. |