CIDER's nREPL Middleware
Much of CIDER's functionality depends on its own nREPL
middleware. Starting
with version 0.11, cider-jack-in
(C-c C-x (C-)j (C-)j)
automatically injects this middle and other dependencies as required.
Note
In the past, if you were setting up CIDER, you might have had to
modify profiles.clj
or profile.boot
. CIDER now handles
everything automatically and you don't need to add anything
special to these files.
Tip
If you don't want cider-jack-in
to inject dependencies automatically, set
cider-inject-dependencies-at-jack-in
to nil
. Note that you'll have to setup
the dependencies yourself (see the section below), just as in CIDER 0.10 and older.
CIDER can also inject a Clojure dependency into your project, which is useful,
for example, if your project defaults to an older version of Clojure than that
supported by the CIDER middleware. Set cider-jack-in-auto-inject-clojure
appropriately to enable this.
If you prefer a standalone REPL, you will need to invoke
cider-connect
instead of cider-jack-in
and manually add the
dependencies to your Clojure project (explained in the following
section).
Setting Up a Standalone REPL
Using Leiningen
Note
It's highly recommended to use Leiningen 2.8.3 or newer, as 2.8.3 is the first release to ship with nREPL 0.5.
Use the convenient plugin for defaults, either in your project's
project.clj
file or in the :repl profile in ~/.lein/profiles.clj
.
:plugins [[cider/cider-nrepl "x.y.z"]]
A minimal profiles.clj
for CIDER would be:
{:repl {:plugins [[cider/cider-nrepl "0.19.0"]]}}
Warning
Be careful not to place this in the :user
profile, as this way CIDER's
middleware will always get loaded, causing lein
to start slower. You really
need it just for lein repl
and this is what the :repl
profile is for.
Using Boot
Note
It's highly recommended to use Boot 2.8.2 or newer, as 2.8.2 is the first release to ship with nREPL 0.4.
Boot users can configure the tool to include the middleware automatically in
all of their projects using a ~/.boot/profile.boot
file like so:
(require 'boot.repl)
(swap! boot.repl/*default-dependencies*
concat '[[cider/cider-nrepl "0.19.0"]])
(swap! boot.repl/*default-middleware*
conj 'cider.nrepl/cider-middleware)
For more information visit boot-clj wiki.
Using Embedded nREPL Server
If you're embedding nREPL in your application, you'll have to start the server with CIDER's own nREPL handler.
(ns my-app
(:require [nrepl.server :as nrepl-server]
[cider.nrepl :refer (cider-nrepl-handler)]))
(defn -main
[]
(nrepl-server/start-server :port 7888 :handler cider-nrepl-handler))
It goes without saying that your project should depend on cider-nrepl
.
Note
Prior to CIDER 0.18, CIDER and cider-nrepl were always released together
and their versions had to match for things to work. But as the prominence
of cider-nrepl grew and many other tools started using it, the two
projects evolved separately and are no longer in tight
lock-step. Any recent version of cider-nrepl should be compatible
with a recent version of CIDER. You can check the required version
of cider-nrepl for your version of CIDER by looking at
cider-required-middleware-version
.