Meta-Field for Taxonomy / Terms

0.4.0-forum-term-meta.php

<?php

// for activation hook ;)

/** @var \wpdb $wpdb */
global $wpdb;

$type = 'forum_term';

$table_name = $wpdb->prefix . $type . 'meta';

$charset_collate = '';
if ( ! empty ( $wpdb->charset ) ) {
	$charset_collate = "DEFAULT CHARACTER SET {$wpdb->charset}";
}

if ( ! empty ( $wpdb->collate ) ) {
	$charset_collate .= " COLLATE {$wpdb->collate}";
}

$sql = "CREATE TABLE IF NOT EXISTS {$table_name} (
        meta_id bigint(20) NOT NULL AUTO_INCREMENT,
        {$type}_id bigint(20) NOT NULL default 0,

        meta_key varchar(255) DEFAULT NULL,
        meta_value longtext DEFAULT NULL,

        UNIQUE KEY meta_id (meta_id)
    ) {$charset_collate};";

$wpdb->query( $sql );

backend.php

<?php

define( 'FORUM_TERM', 'forum_term' );

/** @var \wpdb $wpdb */
global $wpdb;

$identifier        = FORUM_TERM . 'meta';
$wpdb->$identifier = $wpdb->prefix . $identifier;

add_action( 'edit_tag_form_fields', 'forum_termmeta_tag_input_metabox' );
add_action( 'edited_terms', 'forum_termmeta_save_tag_data' );

function forum_termmeta_tag_input_metabox( $tag ) {

	$forum_short = get_metadata(
		FORUM_TERM,
		$tag->term_id,
		'forum_short',
		true
	);

	$forum_sort = get_metadata(
		FORUM_TERM,
		$tag->term_id,
		'forum_sort',
		true
	);

	?>
	<tr class="form-field">
		<th scope="row" valign="top"><label
				for="tag_widget"><?php _e( 'Short' ) ?></label></th>
		<td>
			<input type="text" name="forum_short" id="forum_short"
				value="<?php echo $forum_short ?>"/>
		</td>
	</tr>
	<tr class="form-field">
		<th scope="row" valign="top"><label
				for="tag_widget"><?php _e( 'Sort' ) ?></label></th>
		<td>
			<input type="text" name="forum_sort" id="forum_sort"
			       value="<?php echo $forum_sort ?>"/>
		</td>
	</tr>

<?php
}

function forum_termmeta_save_tag_data( $term_id ) {
	if ( isset( $_POST['forum_short'] ) ) {
		$tag_metadata = esc_attr( $_POST['forum_short'] );

		update_metadata(
			FORUM_TERM,
			$term_id,
			'forum_short',
			$tag_metadata
		);
	}

	if ( isset( $_POST['forum_sort'] ) ) {
		$tag_metadata = esc_attr( $_POST['forum_sort'] );

		update_metadata(
			FORUM_TERM,
			$term_id,
			'forum_sort',
			$tag_metadata
		);
	}
}

get-term-by-meta.php

<?php

	public function get_meta_result($meta_query, $type, $base_table, $id_field ) {
		/** @var \wpdb $wpdb */
		global $wpdb;

		$sql = get_meta_sql(
			$meta_query,
			$type,
			$base_table,
			$id_field
		);

		$join = '';
		if (isset($sql['join'])) {
			$join .= $sql['join'];
		}

		$where = ' 1=1 ';
		if (isset($sql['where'])) {
			$where .= $sql['where'];
		}

		$result = $wpdb->get_col(
			'SELECT * FROM ' . $base_table
			. $join .
			' WHERE ' . $where
		);

		return $result;
	}