# 輸出緩沖中間件 The Output Buffering Middleware enables you to switch between two modes of output buffering:`APPEND`(default) and`PREPEND`mode. The`APPEND`mode will use the existing response body to append the contents. The`PREPEND`mode will create a new response body object and prepend the contents to the output from the existing response body. This middleware should be placed on the center of the middleware stack so it gets executed last. > 輸出緩沖中間件允許您在輸出緩沖的兩種模式之間進行切換: **APPEND** (默認)和 **prepend** 模式。 > > `APPEND`模式將使用現有的響應體附加內容。 > > `prepend` 模式將創建一個新的響應主體對象，并將內容預先添加到現有響應主體的輸出中。 > > 這個中間件應該放在中間件堆棧的中心，這樣它才會最后執行。 ## Usage ~~~php <?php use Slim\Factory\AppFactory; use Slim\Middleware\OutputBufferingMiddleware; use Slim\Psr7\Factory\StreamFactory; require __DIR__ . '/../vendor/autoload.php'; $app = AppFactory::create(); $streamFactory = new StreamFactory(); /** * 有兩種模式 * OutputBufferingMiddleware::APPEND(默認模式)——追加到現有的響應體 * OutputBufferingMiddleware::PREPEND——創建全新的響應體 * The two modes available are * OutputBufferingMiddleware::APPEND (default mode) - Appends to existing response body * OutputBufferingMiddleware::PREPEND - Creates entirely new response body */ $mode = OutputBufferingMiddleware::APPEND; $outputBufferingMiddleware = new OutputBufferingMiddleware($streamFactory, $mode); $app->add($outputBufferingMiddleware); // ... $app->run(); ~~~