Wrapping legacy Application in Framework - .htaccess

Question

I have a legacy-Application with bad code and very untested. It's a large one and so we don't have the manpower to develop a new version in one step.
So I'd like to wrap it into a Symfony application and write the new parts in Symfony. The old classes will then be refactored step by step.
I tried to include the legacys frontcontroller in the application if symfony fires a 404. That works well.
But if i use the app now, i have errors with it's old routing system and symfonys .htaccess.
The symfony .htaccess looks like this
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ app.php [QSA,L]
And the legacy .htaccess looks like this
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !\.(css|jpg|png|gif|js|xml)$ [NC]
RewriteRule ^(.*)$ index.php?_shop_=$1 [L,QSA]
The _shop_ Parameter is used for routing etc. and the Router of the old application depends on it.
Any idea how i can geh this together?

Answer 1

If you want to fix this in .htaccess, you have to define the valid routes.
Let's assume your old applications has the following possible routes and redirects:
/listing => index.php?shop=listing
/detail => index.php?shop=detail
/cart => index.php?shop=cart
Then you'll want your .htaccess to look like this
RewriteCond %{REQUEST_FILENAME} (listing|detail|cart)
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !\.(css|jpg|png|gif|js|xml)$ [NC]
RewriteRule ^(.*)$ index.php?_shop_=$1 [L,QSA]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ app.php [QSA,L]
If this line is too simple for your needs, you can leverage the fact that in rewrite rules the OR flag has an higher precedence, and write something like:
RewriteCond %{REQUEST_FILENAME} ^listing/something$ [OR]
RewriteCond %{REQUEST_FILENAME} ^detail/[complexRegex] [OR]
RewriteCond %{REQUEST_FILENAME} ^cart/...
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !\.(css|jpg|png|gif|js|xml)$ [NC]
RewriteRule ^(.*)$ index.php?_shop_=$1 [L,QSA]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ app.php [QSA,L]
If you want something even more advanced, you'll have to tackle it at the application level (i.e. within index.php or app.php) and not in .htaccess