get_term() WP 1.0

Get all Term data from database by Term ID.

The usage of the get_term function is to apply filters to a term object. It is possible to get a term object from the database before applying the filters.

$term ID must be part of $taxonomy, to get from the database. Failure, might be able to be captured by the hooks. Failure would be the same value as $wpdb returns for the get_row method.

There are two hooks, one is specifically for each term, named 'get_term', and the second is for the taxonomy name, 'term_$taxonomy'. Both hooks gets the term object, and the taxonomy name as parameters. Both hooks are expected to return a Term object.

'get_term' hook - Takes two parameters the term Object and the taxonomy name. Must return term object. Used in get_term() as a catch-all filter for every $term.

{@see 'get_$taxonomy'} hook - Takes two parameters the term Object and the taxonomy name. Must return term object. $taxonomy will be the taxonomy name, so for example, if 'category', it would be 'get_category' as the filter name. Useful for custom taxonomies or plugging into default taxonomies.

Hooks in function

Return

Array/WP_Term/WP_Error/null. Object of the type specified by $output on success. When $output is 'OBJECT', a WP_Term instance is returned. If taxonomy does not exist, a WP_Error is returned. Returns null for miscellaneous failure.

Usage

get_term( $term, $taxonomy, $output, $filter );

$term(int/WP_Term/object) (required)

If integer, term data will be fetched from the database, or from the cache if available. If stdClass object (as in the results of a database query), will apply filters and return a WP_Term object corresponding to the $term data. If WP_Term, will return $term.

$taxonomy(string)

Taxonomy name that $term is part of.
Default: ''

$output(string)

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(string)

Optional.
Default: raw or no WordPress defined filter will applied

Code of get term: wp-includes/taxonomy.php ^{VER 5.1.1}

<?php
function get_term( $term, $taxonomy = '', $output = OBJECT, $filter = 'raw' ) {
	if ( empty( $term ) ) {
		return new WP_Error( 'invalid_term', __( 'Empty Term.' ) );
	}

	if ( $taxonomy && ! taxonomy_exists( $taxonomy ) ) {
		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
	}

	if ( $term instanceof WP_Term ) {
		$_term = $term;
	} elseif ( is_object( $term ) ) {
		if ( empty( $term->filter ) || 'raw' === $term->filter ) {
			$_term = sanitize_term( $term, $taxonomy, 'raw' );
			$_term = new WP_Term( $_term );
		} else {
			$_term = WP_Term::get_instance( $term->term_id );
		}
	} else {
		$_term = WP_Term::get_instance( $term, $taxonomy );
	}

	if ( is_wp_error( $_term ) ) {
		return $_term;
	} elseif ( ! $_term ) {
		return null;
	}

	// Ensure for filters that this is not empty.
	$taxonomy = $_term->taxonomy;

	/**
	 * Filters a taxonomy term object.
	 *
	 * @since 2.3.0
	 * @since 4.4.0 `$_term` is now a `WP_Term` object.
	 *
	 * @param WP_Term $_term    Term object.
	 * @param string  $taxonomy The taxonomy slug.
	 */
	$_term = apply_filters( 'get_term', $_term, $taxonomy );

	/**
	 * Filters a taxonomy term object.
	 *
	 * The dynamic portion of the filter name, `$taxonomy`, refers
	 * to the slug of the term's taxonomy.
	 *
	 * @since 2.3.0
	 * @since 4.4.0 `$_term` is now a `WP_Term` object.
	 *
	 * @param WP_Term $_term    Term object.
	 * @param string  $taxonomy The taxonomy slug.
	 */
	$_term = apply_filters( "get_{$taxonomy}", $_term, $taxonomy );

	// Bail if a filter callback has changed the type of the `$_term` object.
	if ( ! ( $_term instanceof WP_Term ) ) {
		return $_term;
	}

	// Sanitize term, according to the specified filter.
	$_term->filter( $filter );

	if ( $output == ARRAY_A ) {
		return $_term->to_array();
	} elseif ( $output == ARRAY_N ) {
		return array_values( $_term->to_array() );
	}

	return $_term;
}

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