原型

update_nag()

返回值

(false|void)  

源文件

路径:wp-admin/includes/update.php

<?php
...
function update_nag() {
	if ( is_multisite() && !current_user_can('update_core') )
		return false;
	global $pagenow;
	if ( 'update-core.php' == $pagenow )
		return;
	$cur = get_preferred_from_update_core();
	if ( ! isset( $cur->response ) || $cur->response != 'upgrade' )
		return false;
	if ( current_user_can( 'update_core' ) ) {
		$msg = sprintf(
			/* translators: 1: Codex URL to release notes, 2: new WordPress version, 3: URL to network admin, 4: accessibility text */
			__( '<a href="%1$s">WordPress %2$s</a> is available! <a href="%3$s" aria-label="%4$s">Please update now</a>.' ),
			sprintf(
				/* translators: %s: WordPress version */
				esc_url( __( 'https://codex.wordpress.org/Version_%s' ) ),
				$cur->current
			),
			$cur->current,
			network_admin_url( 'update-core.php' ),
			esc_attr__( 'Please update WordPress now' )
		);
	} else {
		$msg = sprintf(
			/* translators: 1: Codex URL to release notes, 2: new WordPress version */
			__( '<a href="%1$s">WordPress %2$s</a> is available! Please notify the site administrator.' ),
			sprintf(
				/* translators: %s: WordPress version */
				esc_url( __( 'https://codex.wordpress.org/Version_%s' ) ),
				$cur->current
			),
			$cur->current
		);
	}
	echo "<div class='update-nag'>$msg</div>";
}
...
?>

其他

英文文档:https://developer.wordpress.org/reference/functions/update_nag/