When designing RESTful applications you will be doing a lot of "PATCH" and "DELETE" request, but most browsers don't support methods other than "GET" and "POST" when it comes to submitting forms.
There is a pattern to solve this (pioneered by Rails) using a hidden "_method" field in the form and swapping out the "POST" method for whatever is in that field.
We can do this with middleware in reitit like this:
(or (get-in request [:form-params "_method"]) ;; look for "_method" field in :form-params
(get-in request [:multipart-params "_method"])))) ;; or in :multipart-params
:wrap (fn [handler]
(if-let [fm (and (= :post (:request-method request)) ;; if this is a :post request
(hidden-method request))] ;; and there is a "_method" field
(handler (assoc request :request-method fm)) ;; replace :request-method
And apply the middleware like this:
[reitit.ring.middleware.parameters/parameters-middleware ;; needed to have :form-params in the request map
reitit.ring.middleware.multipart/multipart-middleware ;; needed to have :multipart-params in the request map
wrap-hidden-method]}) ;; our hidden method wrapper
(NOTE: This middleware must be placed here and not inside the route data given to
reitit.ring/handler. This is so that our middleware is applied before reitit matches the request with a specific handler using the wrong method.)