anon_id = $anon_id; $this->platform = $platform; $this->consent = $consent; } /** * Retrieve the test variation for a provided A/B test. * * @param string $test_name Name of the A/B test. * @return mixed|null A/B test variation, or null on failure. */ public function get_variation( $test_name ) { // Default to the control variation when users haven't consented to tracking. if ( ! $this->consent ) { return 'control'; } $variation = $this->fetch_variation( $test_name ); // If there was an error retrieving a variation, conceal the error for the consumer. if ( is_wp_error( $variation ) ) { return 'control'; } return $variation; } /** * Fetch and cache the test variation for a provided A/B test from WP.com. * * ExPlat returns a null value when the assigned variation is control or * an assignment has not been set. In these instances, this method returns * a value of "control". * * @param string $test_name Name of the A/B test. * @return array|\WP_Error A/B test variation, or error on failure. */ protected function fetch_variation( $test_name ) { // Make sure test name exists. if ( ! $test_name ) { return new \WP_Error( 'test_name_not_provided', 'A/B test name has not been provided.' ); } // Make sure test name is a valid one. if ( ! preg_match( '/^[A-Za-z0-9_]+$/', $test_name ) ) { return new \WP_Error( 'invalid_test_name', 'Invalid A/B test name.' ); } // Return internal-cached test variations. if ( isset( $this->tests[ $test_name ] ) ) { return $this->tests[ $test_name ]; } // Return external-cached test variations. if ( ! empty( get_transient( 'abtest_variation_' . $test_name ) ) ) { return get_transient( 'abtest_variation_' . $test_name ); } // Make the request to the WP.com API. $response = $this->request_variation( $test_name ); // Bail if there was an error or malformed response. if ( is_wp_error( $response ) || ! is_array( $response ) || ! isset( $response['body'] ) ) { return new \WP_Error( 'failed_to_fetch_data', 'Unable to fetch the requested data.' ); } // Decode the results. $results = json_decode( $response['body'], true ); // Bail if there were no resultsreturned. if ( ! is_array( $results ) ) { return new \WP_Error( 'unexpected_data_format', 'Data was not returned in the expected format.' ); } // Store the variation in our internal cache. $this->tests[ $test_name ] = $results['variations'][ $test_name ] ?? null; $variation = $results['variations'][ $test_name ] ?? 'control'; // Store the variation in our external cache. if ( ! empty( $results['ttl'] ) ) { set_transient( 'abtest_variation_' . $test_name, $variation, $results['ttl'] ); } return $variation; } /** * Perform the request for a variation of a provided A/B test from WP.com. * * @param string $test_name Name of the A/B test. * @return array|\WP_Error A/B test variation error on failure. */ protected function request_variation( $test_name ) { $args = array( 'experiment_name' => $test_name, 'anon_id' => rawurlencode( $this->anon_id ), 'woo_country_code' => rawurlencode( get_option( 'woocommerce_default_country', 'US:CA' ) ), ); $args = apply_filters( 'woocommerce_explat_request_args', $args ); $url = add_query_arg( $args, sprintf( 'https://public-api.wordpress.com/wpcom/v2/experiments/0.1.0/assignments/%s', $this->platform ) ); $get = wp_remote_get( $url ); return $get; } }