usermanager-reitit-example

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#+title: Example Web Application in Clojure

This repo is a simple web application using Integrant, Ring, Reitit, and Selmer connected to a local SQLite database.

For learning purpose, I redid from scratch the very useful [[https://github.com/seancorfield/usermanager-example][Sean Corfield's usermanager repo]] and decided to move some libraries to learn them too in the process.

• [[https://github.com/weavejester/compojure][Compojure]] -> [[https://github.com/metosin/reitit][Reitit]]
• [[https://github.com/stuartsierra/component][Component]] -> [[https://github.com/weavejester/integrant][Integrant]]

A Single Page App version that use [[https://github.com/prestancedesign/inertia-clojure][Inertia-clojure]] library can be found [[https://github.com/prestancedesign/reagent-inertia-reitit-integrant-fullstack][here]].

** Requirements

This example assumes that you have the [[https://clojure.org/guides/deps_and_cli][Clojure CLI]] installed, and provides a =deps.edn= file.

Clojure 1.10 (or later) is required. The "model" of this example app uses namespace-qualified keys in hash maps. It uses [[https://cljdoc.org/d/seancorfield/next.jdbc][next.jdbc]] -- the "next generation" JDBC library for Clojure -- which produces namespace-qualified hash maps from result sets.

** Usage *** Run the Application Clone the repo, =cd= into it, then follow below to /Run the Application/ or /Run the application/ in REPL. You can launch the application by directly calling the namespace which contains the =-main= function in an terminal #+begin_src sh $ clj -m usermanager.system #+end_src or more conveniently, using an alias configured in =deps.edn= file. #+begin_src sh $ clj -A:server #+end_src Now acces the app at: [[http://localhost:3000/][http://localhost:3000/]]. *** Run the Application in REPL #+begin_src sh $ clj -A:dev #+end_src Once REPL starts, run the system: #+begin_src clojure user=> (go) #+end_src Now acces the app at: [[http://localhost:3000/][http://localhost:3000/]].

** Build an Uberjar For production deployment, you typically want to build an "uberjar" -- a =.jar= file that contains Clojure itself and all of the code from your application and its dependencies, so that you can run it with the =java -jar= command.

The =build.clj= file -- mentioned above -- contains a =ci= task that:

• cleans up the target folder
• compiles the application (sometimes called "AOT compilation")
• produces a standalone .jar file #+begin_src sh clojure -T:build ci #+end_src

You should see something like this: #+begin_src sh Cleaning target...

 Skipping pom.xml because :lib and/or :version were omitted...
 Copying src, resources...
 Compiling system.main...
 2022-05-25 18:20:13.069:INFO::main: Logging initialized @3981ms to org.eclipse.jetty.util.log.StdErrLog
 Building uberjar target/reitit-example-standalone.jar...

#+end_src

The =target= folder will be created if it doesn't exist and it will include a =classes= folder containing all of the compiled Clojure source code from the =usermanager= application /and all of its dependencies/ including Clojure itself: #+begin_src sh $ ls target/classes/ cheshire clojure clout com compojure crypto instaparse json_html layouts medley next public ring selmer usermanager views #+end_src

It will also include the standalone =.jar= file which you can run like this:

#+begin_src sh java -jar target/example-standalone.jar #+end_src

This should behave the same as the /Run the Application/ example above.

This JAR file can be deployed to any server that have Java installed and run with no other external dependencies or files.

** License & Copyright

Copyright (c) 2015-2022 Sean Corfield / Michaël SALIHI.

Distributed under the Apache Source License 2.0.