current_version = $current_version;
$this->plugin_path = $plugin_path;
add_action( "in_plugin_update_message-$plugin_path", [ $this, 'maybe_run' ] );
}
/**
* Test if there is a plugin upgrade notice and displays it if so.
*
* Expects to fire during "in_plugin_update_message-{plugin_path}", therefore
* this should only run if WordPress has detected that an upgrade is indeed
* available.
*/
public function maybe_run() {
$this->test_for_upgrade_notice();
if ( $this->upgrade_notice ) {
$this->display_message();
}
}
/**
* Tests to see if an upgrade notice is available.
*/
protected function test_for_upgrade_notice() {
$cache_key = $this->cache_key();
$this->upgrade_notice = get_transient( $cache_key );
if ( false === $this->upgrade_notice ) {
$this->discover_upgrade_notice();
}
set_transient( $cache_key, $this->upgrade_notice, $this->cache_expiration() );
}
/**
* Returns a cache key unique to the current plugin path and version, that
* still fits within the 45-char limit of regular WP transient keys.
*
* @return string
*/
protected function cache_key() {
return 'tribe_plugin_upgrade_notice-' . hash( 'crc32b', $this->plugin_path . $this->current_version );
}
/**
* Returns the period of time (in seconds) for which to cache plugin upgrade messages.
*
* @return int
*/
protected function cache_expiration() {
/**
* Number of seconds to cache plugin upgrade messages for.
*
* Defaults to one day, which provides a decent balance between efficiency savings
* and allowing for the possibility that some upgrade messages may be changed or
* rescinded.
*
* @var int $cache_expiration
*/
return (int) apply_filters( 'tribe_plugin_upgrade_notice_expiration', DAY_IN_SECONDS, $this->plugin_path );
}
/**
* Looks at the current stable plugin readme.txt and parses to try and find the first
* available upgrade notice relating to a plugin version higher than this one.
*
* By default, WP SVN is the source.
*/
protected function discover_upgrade_notice() {
/**
* The URL for the current plugin readme.txt file.
*
* @var string $url
* @var string $plugin_path
*/
$readme_url = apply_filters( 'tribe_plugin_upgrade_readme_url',
$this->form_wp_svn_readme_url(),
$this->plugin_path
);
if ( ! empty( $readme_url ) ) {
$response = wp_safe_remote_get( $readme_url );
}
if ( ! empty( $response ) && ! is_wp_error( $response ) ) {
$readme = $response['body'];
}
if ( ! empty( $readme ) ) {
$this->parse_for_upgrade_notice( $readme );
$this->format_upgrade_notice();
}
/**
* The upgrade notice for the current plugin (may be empty).
*
* @var string $upgrade_notice
* @var string $plugin_path
*/
return apply_filters( 'tribe_plugin_upgrade_notice',
$this->upgrade_notice,
$this->plugin_path
);
}
/**
* Forms the expected URL to the trunk readme.txt file as it is on WP SVN
* or an empty string if for any reason it cannot be determined.
*
* @return string
*/
protected function form_wp_svn_readme_url() {
$parts = explode( '/', $this->plugin_path );
$slug = empty( $parts[0] ) ? '' : $parts[0];
return esc_url( "https://plugins.svn.wordpress.org/$slug/trunk/readme.txt" );
}
/**
* Given a standard Markdown-format WP readme.txt file, finds the first upgrade
* notice (if any) for a version higher than $this->current_version.
*
* @param string $readme
* @return string
*/
protected function parse_for_upgrade_notice( $readme ) {
$in_upgrade_notice = false;
$in_version_notice = false;
$readme_lines = explode( "\n", $readme );
foreach ( $readme_lines as $line ) {
// Once we leave the Upgrade Notice section (ie, we encounter a new section header), bail
if ( $in_upgrade_notice && 0 === strpos( $line, '==' ) ) {
break;
}
// Look out for the start of the Upgrade Notice section
if ( ! $in_upgrade_notice && preg_match( '/^==\s*Upgrade\s+Notice\s*==/i', $line ) ) {
$in_upgrade_notice = true;
}
// Also test to see if we have left the version specific note (ie, we encounter a new sub heading or header)
if ( $in_upgrade_notice && $in_version_notice && 0 === strpos( $line, '=' ) ) {
break;
}
// Look out for the first applicable version-specific note within the Upgrade Notice section
if ( $in_upgrade_notice && ! $in_version_notice && preg_match( '/^=\s*\[?([0-9\.]{3,})\]?\s*=/', $line, $matches ) ) {
// Is this a higher version than currently installed?
if ( version_compare( $matches[1], $this->current_version, '>' ) ) {
$in_version_notice = true;
}
}
// Copy the details of the upgrade notice for the first higher version we find
if ( $in_upgrade_notice && $in_version_notice ) {
$this->upgrade_notice .= $line . "\n";
}
}
}
/**
* Convert the plugin version header and any links from Markdown to HTML.
*/
protected function format_upgrade_notice() {
// Convert [links](http://...) to tags
$this->upgrade_notice = preg_replace(
'/\[([^\]]*)\]\(([^\)]*)\)/',
'${1}',
$this->upgrade_notice
);
// Convert =4.0= headings to 4.0
tags
$this->upgrade_notice = preg_replace(
'/=\s*([a-zA-Z0-9\.]{3,})\s*=/',
'${1}
',
$this->upgrade_notice
);
}
/**
* Render the actual upgrade notice.
*
* Please note if plugin-specific styling is required for the message, you can
* use an ID generated by WordPress for one of the message's parent elements
* which takes the form "{plugin_name}-update". Example:
*
* #the-events-calendar-update .tribe-plugin-update-message { ... }
*/
public function display_message() {
$notice = wp_kses_post( $this->upgrade_notice );
echo " $notice
";
}
}