WordPress│参照した記事にショートコードでカスタムフィールドの値を割り当てる方法

//汎用
function motoki_shortcode_custom_field( $atts ) {
	$post = get_post();

	$atts = shortcode_atts(
		array(
			'field' => '', 
			'type'  => 'text',
		),
		$atts,
		'custom_field'
	);

	$field_value = SCF::get( $atts['field'], $post->ID );

	if (empty($field_value)) {
		return 'No such custom field';
	}

	switch ( $atts['type'] ) {
		case 'text':
		case 'textarea':
			return $field_value;
		case 'image':
			return wp_get_attachment_image( $field_value, 'large' );
		case 'checkbox':
			return implode( ', ', $field_value );
		case 'radio':
			return $field_value;
		default:
			return 'Invalid type specified';
	}
}
add_shortcode( 'custom_field', 'motoki_shortcode_custom_field' );

//ボタン（SWELL）
function motoki_btn_shortcode( $atts = array(), $content = null ) {
	$atts = shortcode_atts(
		array(
			'field_name' => 'scf_btn',
			'text'       => 'no_name',
		),
		$atts,
		'motoki_btn'
	);

	$post_id = get_the_ID();

	$field_value = SCF::get( $atts['field_name'], $post_id );

	if (empty($field_value)) {
		return 'No such custom field';
	}

	if ( $field_value ) {
		$shortcode = '<div class="swell-block-button is-style-btn_normal"><a href="' . esc_url( $field_value ) . '" class="swell-block-button__link"><span>' . esc_html( $atts['text'] ) . '</span></a></div>';
		return $shortcode;
	} else {
		return '';
	}
}
add_shortcode( 'scf_btn', 'motoki_btn_shortcode' );

//GoogleMap
function motoki_google_map_shortcode() {
	$post = get_post();

	$map_url = SCF::get( 'scf_map', $post->ID );

	if (empty($map_url)) {
		return 'No such custom field';
	}

	return '<iframe src="' . esc_url( $map_url ) . '" width="600" height="450" style="border:0;" allowfullscreen="" loading="lazy"></iframe>';
}
add_shortcode( 'scf_map', 'motoki_google_map_shortcode' );

//Twitter
function twitter_shortcode() {
	$post_id = get_the_ID();

	$field_value = SCF::get( 'scf_twitter', $post_id );

	if (empty($field_value)) {
		return 'No such custom field';
	}

	if ( $field_value ) {
		$username  = basename( parse_url( $field_value, PHP_URL_PATH ) );
		$shortcode = '<a class="twitter-timeline" data-height="500" data-width="375" href="https://twitter.com/' . esc_html( $username ) . '">Tweets by ' . esc_html( $username ) . '</a><script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>';
		return $shortcode;
	} else {
		return '';
	}
}
add_shortcode( 'scf_twitter', 'twitter_shortcode' );