模擬 Apache mod_rewrite 轉送

透過 app.yaml 參照的 PHP 指令碼，可以模擬基本 Apachemod_rewrite 功能，該指令碼會載入所需的指令碼。本範例模擬常見的 PHP 模式；此模式預期 $_GET['q'] 變數會包含要求路徑。

關於「mod_rewrite.php」

如要啟用 mod_rewrite 功能，應用程式必須包括 mod_rewrite.php；向應用程式提出執行要求轉送的所有要求將會叫用這個指令碼。如同註解所述，指令碼會檢查根層級 PHP 指令碼是否存在，並在 $_SERVER['REQUEST_URI'] 的路徑部分放入 $_GET['q'] 變數時叫用這些指令碼。

<?php
/**
 * @file
 * Provide basic mod_rewrite like functionality.
 *
 * Pass through requests for root php files and forward all other requests to
 * index.php with $_GET['q'] equal to path. The following are examples that
 * demonstrate how a request using mod_rewrite.php will appear to a PHP script.
 *
 * - /install.php: install.php
 * - /update.php?op=info: update.php?op=info
 * - /foo/bar: index.php?q=/foo/bar
 * - /: index.php?q=/
 */

$path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);

// Provide mod_rewrite like functionality. If a php file in the root directory
// is explicitly requested then load the file, otherwise load index.php and
// set get variable 'q' to $_SERVER['REQUEST_URI'].
if (dirname($path) == '/' && pathinfo($path, PATHINFO_EXTENSION) == 'php') {
  $file = pathinfo($path, PATHINFO_BASENAME);
}
else {
  $file = 'index.php';

  // Provide mod_rewrite like functionality by using the path which excludes
  // any other part of the request query (ie. ignores ?foo=bar).
  $_GET['q'] = $path;
}

// Override the script name to simulate the behavior without mod_rewrite.php.
// Ensure that $_SERVER['SCRIPT_NAME'] always begins with a / to be consistent
// with HTTP request and the value that is normally provided.
$_SERVER['SCRIPT_NAME'] = '/' . $file;
require $file;

範例應用程式

以下範例是為預期 $_GET['q'] 而編寫的簡易應用程式。

app.yaml

如您所見，這個 app.yaml 檔案指出這個應用程式會提供兩個根層級的 PHP 指令碼，並從名為 downloads 的目錄提供靜態檔案。

application: mod_rewrite_simulator
version: 1
runtime: php55
api_version: 1

handlers:
# Example of handler which should be placed above the catch-all handler.
- url: /downloads
  static_dir: downloads

# Catch all unhandled requests and pass to mod_rewrite.php which will simulate
# mod_rewrite by forwarding the requests to index.php?q=... (or other root-level
# PHP file if specified in incoming URL.
- url: /.*
  script: mod_rewrite.php

index.php

index.php 是路由器樣式的 index.php，會讀取 $_GET['q'] 來判斷要求路徑。

<?php

if ($_GET['q'] == '/help') {
  echo 'This is some help text.';
  exit;
}

echo 'Welcome to the site!';

other.php

以下是可直接呼叫的根層級指令碼範例。許多 PHP 架構都有類似 install.php 或 update.php 的指令碼，行為也類似。

<?php

echo 'Welcome to the other site.';

要求範例

依據上述的應用程式範例，下列要求會依所示方式處理。

  • / 翻譯成 index.php，並使用 $_GET['q'] = '/'
  • /help 翻譯成 index.php，並使用 $_GET['q'] = '/help'
  • /other.php 翻譯成 other.php，並使用 $_GET['q'] = null
  • /downloads/foo_17.png 翻譯成 downloads/foo_17.png

避免使用 mod_rewrite.php

許多 PHP 架構已不再依附於 $_GET['q']。而是使用 $_SERVER['REQUEST_URI']，無論有無 mod_rewrite 都能運作。因此，後者是 App Engine 的偏好方法。

如同用於 mod_rewrite.php，使用 REQUEST_URI 的乾淨方法如下所示：

<?php

$path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);

if ($path == '/help') {
  echo 'This is some help text.';
  exit;
}

echo 'Welcome to the site!';