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<?php |
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|
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namespace ABlocksLinkGuard; |
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|
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if ( ! defined( 'ABSPATH' ) ) { |
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exit; // Exit if accessed directly. |
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} |
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|
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use ABlocks\Interfaces\AddonInterface; |
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use ABlocks\Classes\CacheBackend; |
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|
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/** |
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* Link Guard addon. |
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* |
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* Writers link to posts that are scheduled but not live yet. Until the target |
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* publishes, a visitor who follows that link gets an error page. This addon |
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* takes those links out of the rendered content — the anchor text stays, the |
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* `<a>` goes — and puts them back the moment the target goes live. |
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* |
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* Nothing is rewritten in the database. The decision is made at render time |
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* from the target's current status, so publishing, unpublishing, trashing or |
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* making a post private all take effect without touching the posts that link |
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* to it. What *is* stored is only the expensive part: which post a URL points |
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* at (see `Frontend::lookup()`). |
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* |
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* The rendered HTML never depends on who is viewing, so page caches stay valid. |
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* The one thing a page cache cannot see is a *different* post changing status, |
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* which is why `Invalidation` keeps a reverse index and announces the posts |
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* whose output just changed. |
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*/ |
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final class LinkGuard implements AddonInterface { |
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|
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private $addon_name = 'link-guard'; |
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|
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private function __construct() { |
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$this->define_constants(); |
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$this->init_addon(); |
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} |
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|
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public function define_constants() { |
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define( 'ABLOCKS_LINK_GUARD_VERSION', '1.0' ); |
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define( 'ABLOCKS_LINK_GUARD_ADDON_NAME', $this->addon_name ); |
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define( 'ABLOCKS_LINK_GUARD_GENERATION_OPTION', 'ablocks_link_guard_generation' ); |
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} |
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|
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public function init_addon() { |
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add_action( "ablocks/addons/activated_{$this->addon_name}", [ $this, 'addon_activation_hook' ] ); |
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|
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if ( ! \ABlocks\Helper::get_addon_active_status( $this->addon_name ) ) { |
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return; |
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} |
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|
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// Status changes happen in the admin, over REST and in cron (a scheduled |
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// post publishes from wp-cron), so invalidation listens everywhere. |
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Invalidation::init(); |
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|
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if ( ! is_admin() || wp_doing_ajax() ) { |
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Frontend::init(); |
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} |
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} |
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|
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public static function init() { |
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static $instance = false; |
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|
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if ( ! $instance ) { |
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$instance = new self(); |
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} |
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|
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return $instance; |
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} |
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|
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/** |
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* While the addon was off, nothing tracked posts being created or renamed, |
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* so any "this URL is not a post" answer stored before then may be stale. |
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*/ |
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public function addon_activation_hook() { |
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CacheBackend::bump_generation( ABLOCKS_LINK_GUARD_GENERATION_OPTION ); |
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} |
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} |
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|
