投稿者: koji

add_filter( 'get_the_archive_description', 'lf_tags_description', 10, 1 );
function lf_tags_description( $description ) {

    if( ! is_tag() ) {
        return $description;
    }

    /* 処理 */
}

SELECT COUNT(t3.term_id) AS count, t3.term_id, t3.name
FROM wp_terms AS t
INNER JOIN wp_term_taxonomy AS tt ON t.term_id=tt.term_id AND taxonomy='post_tag'
INNER JOIN wp_term_relationships AS r ON tt. term_taxonomy_id=r.term_taxonomy_id
INNER JOIN wp_posts AS p ON r.object_id=p.ID AND p.post_status='publish' AND p.post_type='post'
INNER JOIN wp_term_relationships AS r2 ON p.ID=r2.object_id
INNER JOIN wp_term_taxonomy AS tt2 ON r2.term_taxonomy_id=tt2.term_taxonomy_id AND tt2.taxonomy='category'
INNER JOIN wp_terms AS t2 ON tt2.term_id=t2.term_id AND t2.name='list'
INNER JOIN wp_term_relationships AS r3 ON p.ID=r3.object_id
INNER JOIN wp_term_taxonomy AS tt3 ON r3.term_taxonomy_id=tt3.term_taxonomy_id AND tt3.taxonomy='post_tag'
INNER JOIN wp_terms AS t3 ON tt3.term_id=t3.term_id AND t3.term_id != （表示タグのID）
WHERE t.term_id=（表示タグのID）
GROUP BY t3.term_id
ORDER BY count DESC
LIMIT 5

    $coused_tags = $wpdb->get_results( $sql );
    foreach( $coused_tags as $c ) {
        $desc[] = '<a href="'.get_tag_link( $c->term_id ).'" title="'.$c->count.'">'.$c->name.'</a>';
    }

    return 'このタグと共に使われていることが多いタグ<br>'.implode( '　', $desc );

    $coused_tags_all = wp_get_object_terms( $post_ids, 'post_tag', array(
        'fields' => 'all_with_object_id',
        'exclude' => $tag_id,
    ) );

    if( ! count( $coused_tags_all ) ) {
        return $description;
    }

// タグの出現回数を数える
$coused_tags = array();
foreach( $coused_tags_all as $c ) {
    if( ! isset( $coused_tags[$c->term_id] ) ) {
        $coused_tags[$c->term_id] = array( 'count' => 1, 'obj' => $c );
    } else {
        $coused_tags[$c->term_id]['count']++;
    }
}

// 出現回数の降順でソート
uasort ( $coused_tags , function ($a, $b) {
    return $b['count'] - $a['count'];
} );

// 最大5つを取り出す
$coused_tags = array_slice( $coused_tags, 0, 5, true );

foreach( $coused_tags as $k => $v ) {
    $desc[] = '<a href="'.get_tag_link( $k ).'" title="'.$v['count'].'">'.$v['obj']->name.'</a>';
}

return '「'.urldecode( get_query_var( 'tag' ) ).'」と共に使われていることが多いタグ<br>'.implode( '　', $desc );

$q = new WP_Query( array(
	'post_type'      => 'post',
	'category_name'  => 'list',
	'post_status'    => 'publish',
	'posts_per_page' => -1,
	'fields'         => 'ids',
	'tax_query' => array( // 不要だが母集団を小さくするため
		array( 'taxonomy' => 'asin',
			'operator' => 'EXISTS' ),
    ),
) );

// ids: 投稿に付けられたASINタームの総数（重複無し）
$terms = wp_get_object_terms( $q->posts, 'asin', [ 'fields' => 'ids' ]  );
$term_count = count( $terms );	

// all_with_object_id: 投稿に付けられたASINタームの総数（重複あり、延べ引用数）
$terms = wp_get_object_terms( $q->posts, 'asin', [ 'fields' => 'all_with_object_id' ]  );
$term_count_total = count( $terms );

SELECT COUNT(DISTINCT t.term_id) AS total, COUNT(t.term_id) AS c_total
FROM wp_terms AS t
INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id AND tt.taxonomy = 'asin'
INNER JOIN wp_term_relationships AS r ON tt.term_taxonomy_id = r.term_taxonomy_id
INNER JOIN wp_posts AS p ON r.object_id = p.ID AND p.post_status = 'publish' AND p.post_type = 'post'
INNER JOIN wp_term_relationships AS r2 ON p.ID = r2.object_id
INNER JOIN wp_term_taxonomy AS tt2 ON r2.term_taxonomy_id = tt2.term_taxonomy_id AND tt2.taxonomy = 'category'
INNER JOIN wp_terms AS t2 ON tt2.term_id = t2.term_id AND t2.name = 'list'

SELECT COUNT(DISTINCT t.term_id) AS total, COUNT(t.term_id) AS c_total
FROM wp_terms AS t
INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id
INNER JOIN wp_term_relationships AS r ON tt.term_taxonomy_id = r.term_taxonomy_id
INNER JOIN wp_posts AS p ON r.object_id = p.ID
INNER JOIN wp_term_relationships AS r2 ON p.ID = r2.object_id
INNER JOIN wp_term_taxonomy AS tt2 ON r2.term_taxonomy_id = tt2.term_taxonomy_id
INNER JOIN wp_terms AS t2 ON tt2.term_id = t2.term_id
WHERE tt.taxonomy = 'asin' AND p.post_status = 'publish' AND p.post_type = 'post' AND tt2.taxonomy = 'category' AND t2.name = 'list'

do_action_ref_array( 'phpmailer_init', PHPMailer $phpmailer )

$text_body = （組み立てたテキスト）
add_action( 'phpmailer_init', 'lf_altbody', 10, 1 );
function lf_altbody( $phpmailer ) {
    // $text_body をどうやって受け取る？
}

$text_body = （組み立てたテキスト）
add_action( 'phpmailer_init', function( $phpmailer ) use( $text_body ) {
    $phpmailer->AltBody = $text_body;
}, 10, 1 );

function lf_get_poplists() {
    if ( ! $lists = get_transient( 'LF_POPLISTS' ) {

        // リスト取得処理
        $lists = ...

        set_transient( 'LF_POPLISTS', $lists, HOUR_IN_SECONDS );
    }
    return $lists;
}

// フック名＋引数がキーとなるので array()も明示しておく
if( ! wp_next_scheduled( 'lf_event_poplists', array() ) ) {
    // 第5引数を true にするために第4引数に array() を設定している
    if( ! $ret = wp_schedule_event( time(), 'hourly', 'lf_event_poplists', array(), true ) ) {
        // エラー処理
    }
}

// スケジュール登録したフックとアクションを関連づける
add_action('lf_event_poplists', 'lf_set_poplists', 10, 0);

// アクションの実行
function lf_set_poplists() {

    // リスト取得処理
    $lists = ...

    set_transient( 'LF_POPLISTS', $lists );
}

// 引数あり（引数の数が決まっている場合）
if ( ! wp_next_scheduled( 'lf_event', array( 'a', 'b' ) ) ) {
    if ( ! $ret = wp_schedule_event( time(), 'hourly', 'lf_event', array( 'a', 'b' ), true ) ) {
        // エラー処理
    }
}
add_action( 'lf_event', 'lf_action', 10, 2 );
function lf_action( $arg1, $arg2) {
}

// 引数あり（引数の数が決められない場合）
if ( ! wp_next_scheduled( 'lf_event', array( array( 'a', 'b' ) ) ) ) {
    if ( ! $ret = wp_schedule_event( time(), 'hourly', 'lf_event', array( array( 'a','b ') ), true ) ) {
        // エラー処理
    }
}
add_action( 'lf_event', 'lf_action', 10, 1 );
function lf_action( $arg ) {
}

$etime = new DateTimeImmutable( 'tomorrow 0:01', wp_timezone() );
if ( ! wp_next_scheduled( 'lf_event', array() ) ) {
    if ( ! $ret = wp_schedule_event( $etime->getTimeStamp(), 'daily', 'lf_event', array(), true ) ) {
    }
}