If your Slim Framework application does not have a route that matches the current HTTP request URI, the application invokes its Not Found handler and returns a
HTTP/1.1 404 Not Found response to the HTTP client.
Each Slim Framework application has a default Not Found handler. This handler sets the Response status to
404, it sets the content type to
text/html, and it writes a simple explanation to the Response body.
A Slim Framework application’s Not Found handler is a Pimple service. You can substitute your own Not Found handler by defining a custom Pimple factory method with the application container.
In this example, we define a new
notFoundHandler factory that returns a callable. The returned callable accepts two arguments:
The callable MUST return an appropriate