Add Purge for AMP URL when a Post or Page is Published.

admin/class-fastcgi-purger.php

@@ -90,8 +90,29 @@ public function purge_url( $url, $feed = true ) {
 				break;
 
 		}
+
+		if( ( is_page() || is_single() ) && $nginx_helper_admin->options['purge_amp_urls'] ) {
+			$this->purge_amp_version( $url );
+		}
 
 	}
+
+	/**
+	 * Purge AMP version of a URL.
+	 *
+	 * @param string $url_base The base URL to purge.
+	 */
+	private function purge_amp_version( $url_base ) {
+		$amp_url = $url_base . '/amp/';
+
+		$this->log('- Purging AMP URL | ' . $amp_url);
+
+		if ($this->nginx_helper_admin->options['purge_method'] === 'unlink_files') {
+			$this->delete_cache_file_for($amp_url);
+		} else {
+			$this->do_remote_get($this->purge_base_url() . '/amp/');
+		}
+	}
 
 	/**
 	 * Function to custom purge urls.

admin/class-nginx-helper-admin.php

@@ -278,6 +278,7 @@ public function nginx_helper_default_settings() {
 			'redis_prefix'                     => 'nginx-cache:',
 			'purge_url'                        => '',
 			'redis_enabled_by_constant'        => 0,
+			'purge_amp_urls'                   => 1,
 		);
 
 	}

admin/partials/nginx-helper-general-options.php

@@ -40,6 +40,7 @@
 	'purge_page_on_deleted_comment',
 	'purge_feeds',
 	'smart_http_expire_form_nonce',
+	'purge_amp_urls',
 );
 
 $all_inputs = array();
@@ -548,6 +549,38 @@
 						</td>
 					</tr>
 				</table>
+                <table class="form-table rtnginx-table">
+                    <tr valign="top">
+                        <th scope="row">
+                            <h4>
+								<?php esc_html_e( 'Purge AMP URL:', 'nginx-helper' ); ?>
+                            </h4>
+                        </th>
+                        <td>
+                            <fieldset>
+                                <legend class="screen-reader-text">
+									<span>
+										&nbsp;
+										<?php
+										esc_html_e( 'purge amp urls', 'nginx-helper' );
+										?>
+									</span>
+                                </legend>
+                                <label for="purge_amp_urls">
+                                    <input type="checkbox" value="1" id="purge_amp_urls" name="purge_amp_urls" <?php checked( $nginx_helper_settings['purge_amp_urls'], 1 ); ?> />
+                                    &nbsp;
+									<?php
+									echo wp_kses(
+										__( 'purge <strong>amp urls</strong> along with <strong>posts</strong> & <strong>pages</strong>.', 'nginx-helper' ),
+										array( 'strong' => array() )
+									);
+									?>
+                                </label>
+                                <br />
+                            </fieldset>
+                        </td>
+                    </tr>
+                </table>
 				<table class="form-table rtnginx-table">
 					<tr valign="top">
 						<th scope="row">