shoreleave-remote-ring

shoreleave-remote-ring is an alternative implementation of shoreleave-remote-noir, aiming to be a well-behaved Ring/Compojure library and middleware.

"Installation"

shoreleave-remote-ring is available in Clojars. Add it to your Maven project's pom.xml:

<dependency>
  <groupId>com.cemerick</groupId>
  <artifactId>shoreleave-remote-ring</artifactId>
  <version>0.0.2</version>
</dependency>

or your leiningen project.clj:

[com.cemerick/shoreleave-remote-ring "0.0.2"]

Usage

First, you need to be using (or, aiming to use) shoreleave-remote, a snazzy ClojureScript library implementing a variety of remote call operations.

shoreleave-remote-ring provides the server-side implementation for the HTTP RPC option (implemented in shoreleave.remotes.http-rpc). In general, it supports all the same things that shoreleave-remote-noir does, but:

1. It doesn't depend upon Noir.
2. It is just a couple of functions, including a bit of middleware so you can easily (and functionally) put the remoting support anywhere in your Ring/Compojure stack.
3. It elides some wonky features (looking at you, noir.shoreleave.rpc/remote-ns!).
4. Its defremote macro is a more faithful drop-in defn replacement, and offers some additional knobs.

(FYI, this library and shoreleave-remote-noir may or may not be compatible with Fetch, the library that apparently inspired the genesis of shoreleave-remote.)

1. Define your remotes (server-side, in Clojure)

(ns ...
  (:require [cemerick.shoreleave.rpc :refer (defremote)]))

(defremote remote-fn [arg1 arg2 ...] ...)

2. Mix in the wrap-rpc middleware (still server-side, still Clojure)

With bare Ring:

(ns ...
  (:require [cemerick.shoreleave.rpc :as rpc])
  (:use [ring.middleware params
                         keyword-params
                         nested-params
                         ...]))

(def app (-> #'your-top-level-handler
           rpc/wrap-rpc
           wrap-keyword-params
           wrap-nested-params
           wrap-params
           ...))

…or, if you're using Compojure:

(ns ...
  (:require [cemerick.shoreleave.rpc :as rpc]
            [compojure.handler :as handler]))

(def app (-> #'your-top-level-handler
           rpc/wrap-rpc
           handler/site
           ...))

3. Call your remotes (client-side now, ClojureScript)

(ns ...
  (:require-macros [shoreleave.remotes.macros :as macros])
  (:require [shoreleave.remotes.http-rpc :as rpc]))

(rpc/remote-callback :remote-fn [arg1 arg2 ...] #(js/alert %))

Of course, you can use the shoreleave macro (macros/rpc given the :require above) if you prefer.

4. Give your functions whatever names you like (server-side again, Clojure)

Note the correspondence between the name of the remote function (remote-fn) and the name passed to remote-callback). This is convenient, but will cause confusion and perhaps collisions in large enough codebases. The escape hatch is that defremote can bind a Clojure function to any remote name you like, with just a bit of metadata:

(ns ...
  (:require [cemerick.shoreleave.rpc :refer (defremote)]))

(defremote ^{:remote-name :validations/is-email?} remote-fn
  [arg1 arg2 ...]
  ...)

Now, remote-fn is not the remote name of this function; validations/is-email? is:

(ns ...
  (:require-macros [shoreleave.remotes.macros :as macros])
  (:require [shoreleave.remotes.http-rpc :as rpc]))

(rpc/remote-callback :validations/is-email? ["foo@bar.com"] #(js/alert %))

The value of :remote-name can be any string, keyword, or symbol, but the convention of namespaced keywords (or symbols) is a good one for alleviating issues of collision and confusion. Auto-namespaced keywords (e.g. ::is-email?) can also be used so as to automatically prepend the name of the current namespace (though the notion of exposing the names of server-side namespaces might rightly worry you).

Need Help?

Ping cemerick on freenode irc or twitter if you have questions or would like to contribute patches.

License

Copyright © 2012 Chas Emerick

Licensed under the EPL. (See the file epl-v10.html.)