Redirect Old .php URLs to New Wordpress Page

Question

I have an old website that I'm revamping with a custom new Wordpress theme. The old site had a custom (non-WP based) downloads archive that mapped URLs like this:

/downloads/view.php?id=2

The ID maps to a download item in a separate MySQL database.

I'd like to move everything over to Wordpress in this refresh and I'm going to be using a custom post type to handle the downloads section, with a custom field that maps the "old ID" to the new post. This isn't difficult and I know how to do this, but the issue becomes remapping the old URLs to the new locations.

The issue I see is that the older URLs are all PHP files (have an extension of .php). How would I go about create a plugin or Wordpress function in my theme's functions.php file to redirect these old URLs to a new URL. Essentially, I just need to have a Wordpress function redirect from /downloads/view.php?id=2 to /downloads/2/, or another more optimized URL (/downloads/title-of-archive).

How would I go about handling pages with a URL of "/downloads/view.php" and "/downloads/download.php" and performing the redirect?

I know I can use the .htaccess file, but I'd prefer to do this directly in a Wordpress plugin if possible for portability...

Answer 1

You could do this with rewrites, but honestly, it's not a rewrite what you want. A rewrite would just have the old url to act like the new url instead of redirecting it to the new location. Please not that you still need to make sure /downloads/id/ is handled by your WordPress. Now there you could use rewrite.

Add the following code to your templates function.php:

if ( !function_exists( 'get_current_url' ) ) {
    /**
     * Gets the current displayed url
     * @returns the url
     */
    function get_current_url( ) {
        $url  = isset( $_SERVER['HTTPS'] ) && $_SERVER['HTTPS'] == 'on' ? 'https://' : 'http://';
        $url .= ( strlen( $_SERVER['SERVER_NAME'] ) ? $_SERVER['SERVER_NAME'] : $_SERVER['HTTP_HOST'] );
        $url .= ( strval( $_SERVER['SERVER_PORT'] ) != '80' ) ? $_SERVER['SERVER_PORT'] : '';
        $url .= $_SERVER[ 'REQUEST_URI' ];
        return $url;    
    }
}

/**
 * Permanently redirects old /downloads/view.php?id=X and /downloads/download.php?id=X
 * to /downloads/X/. 
 */
function permanent_301_redirect_downloads() {  

    $matches = array();
    $url = get_current_url();

    // $matches[1] has view or download, and $matches[2] the id
    if ( preg_match( '/downloads\/(view|download)\.php\?id=([0-9]+)\/?$/', $url, $matches ) ) :
        // Fetch the title of the archive. Are these posts? I wouldn't know
        $archive = $matches[2];
        wp_redirect( trailingslashit( home_url('') . '/downloads/' . $archive ) , 301 );  
        exit;
    endif;

}  
add_action( 'template_redirect', 'permanent_301_redirect_downloads' );  

Answer 2

To redirect /downloads/view.php?id={some-name} to /downloads/{some-name}/, add the following to your .htaccess file, before the default WordPress rules

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^downloads/view.php?id=(.+) downloads/$1 [R=301,L]
</IfModule>

It will also let search engines know that your downloads have moved, and to update their index.

Answer 3

I ended up solving the issue by hooking onto the "template_redirect" action. After that, I check if the page is_404() and then check if the URL matches my pattern. I set the appropriate header (301 versus the 404 that normally would be triggered) and perform my redirect. My code is below.

add_action('template_redirect', 'handle_download_urls');

function handle_download_urls(){
    if(is_404()){
        if(preg_match('/\/downloads\/(?:view\.php|download\.php)/', $_SERVER['REQUEST_URI']) && isset($_GET['id'])){
            // Do lookup of post based on custom metadata field
            // Redirect and change header
            status_header(301);
            header('Location: [URL]');
       }
    }
}