mirror of
https://github.com/metosin/reitit.git
synced 2025-12-17 00:11:11 +00:00
f4da07c222
Some checks failed
testsuite / Clojure (Java 11) (push) Has been cancelled
testsuite / Clojure (Java 17) (push) Has been cancelled
testsuite / Clojure (Java 21) (push) Has been cancelled
testsuite / ClojureScript (push) Has been cancelled
testsuite / Lint cljdoc.edn (push) Has been cancelled
testsuite / Check cljdoc analysis (push) Has been cancelled
73 lines
2.1 KiB
Markdown
73 lines
2.1 KiB
Markdown
# Transforming the Middleware Chain
|
|
|
|
There is an extra option in the Ring router (actually, in the underlying middleware-router): `:reitit.middleware/transform` to transform the middleware chain per endpoint. Value should be a function or a vector of functions that get a vector of compiled middleware and should return a new vector of middleware.
|
|
|
|
## Example Application
|
|
|
|
```clj
|
|
(require '[reitit.ring :as ring])
|
|
(require '[reitit.middleware :as middleware])
|
|
|
|
(defn wrap [handler id]
|
|
(fn [request]
|
|
(handler (update request ::acc (fnil conj []) id))))
|
|
|
|
(defn handler [{::keys [acc]}]
|
|
{:status 200, :body (conj acc :handler)})
|
|
|
|
(def app
|
|
(ring/ring-handler
|
|
(ring/router
|
|
["/api" {:middleware [[wrap 1] [wrap 2]]}
|
|
["/ping" {:get {:middleware [[wrap 3]]
|
|
:handler handler}}]])))
|
|
|
|
(app {:request-method :get, :uri "/api/ping"})
|
|
; {:status 200, :body [1 2 3 :handler]}
|
|
```
|
|
|
|
### Reversing the Middleware Chain
|
|
|
|
```clj
|
|
(def app
|
|
(ring/ring-handler
|
|
(ring/router
|
|
["/api" {:middleware [[wrap 1] [wrap 2]]}
|
|
["/ping" {:get {:middleware [[wrap 3]]
|
|
:handler handler}}]]
|
|
{::middleware/transform reverse})))
|
|
|
|
(app {:request-method :get, :uri "/api/ping"})
|
|
; {:status 200, :body [3 2 1 :handler]}
|
|
```
|
|
|
|
## Interleaving Middleware
|
|
|
|
```clj
|
|
(def app
|
|
(ring/ring-handler
|
|
(ring/router
|
|
["/api" {:middleware [[wrap 1] [wrap 2]]}
|
|
["/ping" {:get {:middleware [[wrap 3]]
|
|
:handler handler}}]]
|
|
{::middleware/transform #(interleave % (repeat [wrap :debug]))})))
|
|
|
|
(app {:request-method :get, :uri "/api/ping"})
|
|
; {:status 200, :body [1 :debug 2 :debug 3 :debug :handler]}
|
|
```
|
|
|
|
### Printing Request Diffs
|
|
|
|
```clj
|
|
[metosin/reitit-middleware "0.9.2"]
|
|
```
|
|
|
|
Using `reitit.ring.middleware.dev/print-request-diffs` transformation, the request diffs between each middleware are printed out to the console. To use it, add the following router option:
|
|
|
|
```clj
|
|
:reitit.middleware/transform reitit.ring.middleware.dev/print-request-diffs
|
|
```
|
|
|
|
Sample output:
|
|
|
|
|