Ring-JSON

Standard Ring middleware functions for handling JSON requests and responses.

Installation

To install, add the following to your project :dependencies:

[ring/ring-json "0.5.1"]

Usage

wrap-json-response

The wrap-json-response middleware will convert any response with a collection as a body (e.g. map, vector, set, seq, etc) into JSON:

(require '[ring.middleware.json :refer [wrap-json-response]]
         '[ring.util.response :refer [response]])

(defn handler [request]
  (response {:foo "bar"}))

(def app
  (wrap-json-response handler))

wrap-json-body

The wrap-json-body middleware will parse the body of any request with a JSON content-type into a Clojure data structure, and assign it to the :body key.

This is the preferred way of handling JSON requests.

(use '[ring.middleware.json :only [wrap-json-body]]
     '[ring.util.response :only [response]])

(defn handler [request]
  (prn (get-in request [:body "user"]))
  (response "Uploaded user."))

(def app
  (wrap-json-body handler {:keywords? true :bigdecimals? true}))

wrap-json-params

The wrap-json-params middleware is an alternative to wrap-json-body for when it's convenient to treat a JSON request as a map of parameters. Rather than replace the :body key, the parsed data structure will be assigned to the :json-params. The parameters will also be merged into the standard :params map.

(require '[ring.middleware.json :refer [wrap-json-params]]
         '[ring.util.response :refer [response]])

(defn handler [request]
  (prn (get-in request [:params "user"]))
  (response "Uploaded user."))

(def app
  (wrap-json-params handler))

Note that Ring parameter maps use strings for keys. For consistency, this means that wrap-json-params does not have a :keywords? option. Instead, use the standard Ring wrap-keyword-params function:

(require '[ring.middleware.keyword-params :refer [wrap-keyword-params]])

(def app
  (-> handler
      wrap-keyword-params
      wrap-json-params))

License

Copyright © 2021 James Reeves

Distributed under the MIT License, the same as Ring.