1 files changed, 81 insertions, 0 deletions
diff --git a/plugins/jetpack/modules/shortcodes/unavailable.php b/plugins/jetpack/modules/shortcodes/unavailable.php
new file mode 100644
index 00000000..3c08272f
--- /dev/null
+++ b/plugins/jetpack/modules/shortcodes/unavailable.php
@@ -0,0 +1,81 @@
+<?php //phpcs:ignore WordPress.Files.FileName.InvalidClassFileName
+/**
+ * Display a message on the frontend when we retire a shortcode,
+ * explaining why the shortcode is not available anymore.
+ *
+ * @package Jetpack
+ */
+
+/**
+ * Class Jetpack_Shortcode_Unavailable
+ */
+class Jetpack_Shortcode_Unavailable {
+	/**
+	 * Set up the actions and filters for the class to listen to.
+	 *
+	 * @param array $shortcodes An associative array of keys being the shortcodes that are unavailable, and a string explaining why.
+	 */
+	public function __construct( $shortcodes ) {
+		$this->shortcodes = $shortcodes;
+
+		add_action( 'template_redirect', array( $this, 'add_shortcodes' ) );
+	}
+
+	/**
+	 * For all of our defined unavailable shortcodes, if something else hasn't
+	 * already claimed them, add a handler to nullify their output.
+	 */
+	public function add_shortcodes() {
+		foreach ( array_keys( $this->shortcodes ) as $shortcode ) {
+			if ( ! shortcode_exists( $shortcode ) ) {
+				add_shortcode( $shortcode, array( $this, 'stub_shortcode' ) );
+			}
+		}
+	}
+
+	/**
+	 * Nullify the output of unavailable shortcodes.  Includes a filter to make
+	 * it easier to notify admins that a shortcode that they used is unavailable.
+	 *
+	 * @param array  $atts      Shortcode attributes.
+	 * @param string $content   Post content.
+	 * @param string $shortcode Shortcode name.
+	 *
+	 * @return mixed|void
+	 */
+	public function stub_shortcode( $atts, $content = '', $shortcode = '' ) {
+		$str = '';
+		if ( current_user_can( 'edit_posts' ) && ! empty( $this->shortcodes[ $shortcode ] ) ) {
+			$str = sprintf( '<div><strong>%s</strong></div>', $this->shortcodes[ $shortcode ] );
+		}
+		/**
+		 * Filter the front-end output of unavailable shortcodes.
+		 *
+		 * @module shortcodes
+		 *
+		 * @since 4.5.0
+		 *
+		 * @param string $str The html displayed in lieu of the shortcode.
+		 * @param array $atts The attributes (numeric or named) passed to the shortcode.
+		 * @param string $content The content (if any) between the opening and closing tags.
+		 * @param string $shortcode The shortcode tag used to invoke this.
+		 */
+		return apply_filters( 'jetpack_stub_shortcode', $str, $atts, $content, $shortcode );
+	}
+}
+
+/**
+ * Init class.
+ */
+function jetpack_init_shortcode_unavailable() {
+	new Jetpack_Shortcode_Unavailable(
+		array(
+			'digg'                    => __( 'The Digg API was shut down in 2014.', 'jetpack' ),
+			'blip.tv'                 => __( 'The Blip.tv service has been shut down since August 20th, 2015.', 'jetpack' ),
+			'googlevideo'             => __( 'The Google Video embed service is not available anymore, it has been replaced by YouTube.', 'jetpack' ),
+			'jetpack-email-subscribe' => __( 'The Email Subscribe shortcode is now available as a block in the Block editor.', 'jetpack' ),
+			'lytro'                   => __( 'Lytro has been shut down since March 2019.', 'jetpack' ),
+		)
+	);
+}
+add_action( 'init', 'jetpack_init_shortcode_unavailable' );