Routing

Zodiac uses Reitit for routing. Reitit is an incredibly powerful routing library and is very well documented. We won't duplicate Reitit's documentation here but instead we'll only cover the basics and how to use Retit with Zodiac.

To use routes with Zodiac associate a Retit route definition to the :routes key in the options map passed to [[zodiac.core/start]].

The most basic example looks like:

(ns myapp
  (:require [zodiac.core :as z]))

(def routes
  ["/" {:handler (fn [_]
                   {:status 200
                    :body "ok"})}])

(z/start {:routes routes})

Coercion

The Retit router created when you start Zodiac comes preconfigured with route coercion using Malli. This means that you can validate and coerce the request query, body, form, header and path using using Malli schema definitions.

For example to coerce the :id keyword in the route path you can do the following:

(def routes
  ["/resource/:id" {:handler (fn [{:keys [path-params]
                                   :as request}]
                               {:status 200
                                :body (if (int? (:id path-params))
                                        "Its an int!"
                                        "NOT an int!")})
                    :parameters {:path {:id int?}}}])

By default Reitit includes error handlers to pretty print coersion errors. To override or disable the default error handlers use the :error-handlers option passed to zodiac.core/start.

(ns myapp
  (:require [reitit.coercion :as coercion]
            [zodiac.core :as z]))

(defn coersion-error-handler [req err]
  {:status 500
   :body "ERROR!"})

(z/start {:routes routes
          :error-handlers {::coercion/request-coercion coercion-error-handler}})

I encourage you to read more about defining schemas for different request parameters in the Reitit documentation for defining parameters