Question: How do you implement a 302 redirect in PHP?

Implementing a 302 redirect in PHP is straightforward and commonly used to redirect users temporarily to a different URL. A 302 status indicates that the resource requested has been temporarily moved to another URI, as indicated by the Location header field.

When to Use a 302 Redirect

• Temporary content relocation: When your webpage's content is temporarily moved (e.g., during maintenance).
• A/B testing: To direct traffic to different versions of a page for testing.
• Geolocation-based redirection: Redirecting users based on their geographic location.

Implementing 302 Redirect in PHP

1. Basic 302 Redirect To perform a simple 302 redirect, you can use the header() function in PHP to modify the HTTP headers sent to the client:

   header('Location: http://www.example.com/new-page.php', true, 302);
   exit(); // Don't forget to call exit() after sending headers
   

2. Condition-Based Redirect You might want to redirect users conditionally, for example, based on some business logic or user input:

   if ($user->isLoggedIn()) {
       header('Location: http://www.example.com/dashboard.php', true, 302);
   } else {
       header('Location: http://www.example.com/login.php', true, 302);
   }
   exit();
   

3. Combining with Other Headers Sometimes, additional headers are required before performing a redirect, like setting cookies or handling CORS (Cross-Origin Resource Sharing):

   header('Set-Cookie: name=value; expires=Wed, 29-Jun-2024 12:00:00 GMT; path=/');
   header('Access-Control-Allow-Origin: *');
   header('Location: http://www.example.com/', true, 302);
   exit();
   

Best Practices

• Use exit() After header(): This prevents the script from running further which could lead to unexpected behavior.
• Relative vs. Absolute URLs: While relative URLs can be used in redirects, it's generally safer to use absolute URLs to avoid any confusion about the base URL.
• SEO Considerations: Frequent use of 302 redirects can confuse search engines about which of your pages is canonical. Use them judiciously.

By using the above methods, you can effectively manage temporary redirections in your PHP applications.