term_exists( int|string $term, string $taxonomy = '', int $parent_term = null ): mixed
Determines whether a taxonomy term exists.
Contents
Description
Formerly is_term() , introduced in 2.3.0.
For more information on this and similar theme functions, check out the Conditional Tags article in the Theme Developer Handbook.
Parameters
-
$term
int|string Required -
The term to check. Accepts term ID, slug, or name.
-
$taxonomy
string Optional -
The taxonomy name to use.
Default:
''
-
$parent_term
int Optional -
ID of parent term under which to confine the exists search.
Default:
null
Return
mixed Returns null if the term does not exist.
Returns the term ID if no taxonomy is specified and the term ID exists.
Returns an array of the term ID and the term taxonomy ID if the taxonomy is specified and the pairing exists.
Returns 0 if term ID 0 is passed to the function.
Source
File: wp-includes/taxonomy.php
.
View all references
function term_exists( $term, $taxonomy = '', $parent_term = null ) {
global $_wp_suspend_cache_invalidation;
if ( null === $term ) {
return null;
}
$defaults = array(
'get' => 'all',
'fields' => 'ids',
'number' => 1,
'update_term_meta_cache' => false,
'order' => 'ASC',
'orderby' => 'term_id',
'suppress_filter' => true,
);
// Ensure that while importing, queries are not cached.
if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
// @todo Disable caching once #52710 is merged.
$defaults['cache_domain'] = microtime();
}
if ( ! empty( $taxonomy ) ) {
$defaults['taxonomy'] = $taxonomy;
$defaults['fields'] = 'all';
}
/**
* Filters default query arguments for checking if a term exists.
*
* @since 6.0.0
*
* @param array $defaults An array of arguments passed to get_terms().
* @param int|string $term The term to check. Accepts term ID, slug, or name.
* @param string $taxonomy The taxonomy name to use. An empty string indicates
* the search is against all taxonomies.
* @param int|null $parent_term ID of parent term under which to confine the exists search.
* Null indicates the search is unconfined.
*/
$defaults = apply_filters( 'term_exists_default_query_args', $defaults, $term, $taxonomy, $parent_term );
if ( is_int( $term ) ) {
if ( 0 === $term ) {
return 0;
}
$args = wp_parse_args( array( 'include' => array( $term ) ), $defaults );
$terms = get_terms( $args );
} else {
$term = trim( wp_unslash( $term ) );
if ( '' === $term ) {
return null;
}
if ( ! empty( $taxonomy ) && is_numeric( $parent_term ) ) {
$defaults['parent'] = (int) $parent_term;
}
$args = wp_parse_args( array( 'slug' => sanitize_title( $term ) ), $defaults );
$terms = get_terms( $args );
if ( empty( $terms ) || is_wp_error( $terms ) ) {
$args = wp_parse_args( array( 'name' => $term ), $defaults );
$terms = get_terms( $args );
}
}
if ( empty( $terms ) || is_wp_error( $terms ) ) {
return null;
}
$_term = array_shift( $terms );
if ( ! empty( $taxonomy ) ) {
return array(
'term_id' => (string) $_term->term_id,
'term_taxonomy_id' => (string) $_term->term_taxonomy_id,
);
}
return (string) $_term;
}
Hooks
-
apply_filters( 'term_exists_default_query_args',
array $defaults ,int|string $term ,string $taxonomy ,int|null $parent_term ) -
Filters default query arguments for checking if a term exists.
Changelog
Version | Description |
---|---|
6.0.0 | Converted to use get_terms() . |
3.0.0 | Introduced. |
User Contributed Notes
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The returned array of
returns a string for the ID instead of ints. If you need int values you’ll need to convert them to ints.
Checks to see if ‘Uncategorized’ category exists
Check if the ‘Uncategorized’ category exists
Note:
term_exists()
runs a database query.get_term()
can be used for the same purpose, except it uses the term cache.Checks to see if ‘Untagged’ post_tag category exists
Note:
term_exists()
runs a database query.get_term()
can be used for the same purpose, except it uses the term cache.