README.md

component

A Clojang life-cycle implementation of the Component library for use in large/complex applications

Contents

• About
• Usage
• Donating
• License

About ↟

While the Clojang agent is useful for emulating some of the convenience of the Erlang shell and LFE REPL, it may be too fragile for systems deployments, or a developer may prefer to use more common idioms in Clojure deployments, namely the use of the Component library.

This project provides the same functionality that the agent does, but in a form that can be easily integrated with other Clojure components as part of a larger system. In particular, a default node component is provided -- this may be either used as is, or as the basis of a customized component, specially suited for your needs.

Usage ↟

Basic usage is as follows:

1. Start up the REPL:

$ lein repl

  ___| |      _)
 |     |  _ \  |  _` | __ \   _` |
 |     | (   | | (   | |   | (   |
\____|_|\___/  |\__,_|_|  _|\__, |
           ___/             |___/
----------      ------------     -
-  c o m p o n e n t  ------------
----------------------------------

Clojure 1.9.0
Java HotSpot(TM) 64-Bit Server VM 1.8.0_161-b12
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

[clojang.component.repl] λ=>

2. Start the Clojang default node component, which is part of the sample system:

[clojang.component.repl] λ=> (startup)

2018-08-04T15:33:05.475 [nREPL-worker-0] INFO clojang.component.components.config:39 - Starting config component ...
2018-08-04T15:33:05.510 [nREPL-worker-0] DEBUG clojang.component.components.config:40 - Started config component.
2018-08-04T15:33:05.513 [nREPL-worker-0] INFO clojang.component.components.logging:16 - Starting logging component ...
2018-08-04T15:33:05.514 [nREPL-worker-0] DEBUG clojang.component.components.logging:19 - Setting up logging with level :debug
2018-08-04T15:33:05.514 [nREPL-worker-0] DEBUG clojang.component.components.logging:20 - Logging namespaces: [clojang com.ericsson.otp.erlang jiface]
2018-08-04T15:33:05.519 [nREPL-worker-0] DEBUG clojang.component.components.logging:22 - Started logging component.
2018-08-04T15:33:05.520 [nREPL-worker-0] INFO clojang.component.components.epmd:45 - Starting Erlang Port Mapper Daemon component ...
2018-08-04T15:33:05.644 [nREPL-worker-0] DEBUG clojang.component.components.epmd:57 - Started the Erlang Port Mapper Daemon process.
2018-08-04T15:33:05.644 [nREPL-worker-0] DEBUG clojang.component.components.epmd:58 - Started Erlang Port Mapper Daemon component.
2018-08-04T15:33:05.646 [nREPL-worker-0] INFO clojang.component.components.default-node:23 - Starting default node component ...
2018-08-04T15:33:05.648 [nREPL-worker-0] INFO clojang.agent.startup:34 - Bringing up OTP node on clojang@spacemac ...
2018-08-04T15:33:05.657 [nREPL-worker-0] INFO clojang.agent.startup:26 - Registered nodes with message boxes: ["default"]
:running

3. Make calls using the convencient API at clojang.component.core:

[clojang.component.repl] λ=> (core/node-name)
"clojang@spacemac"
[clojang.component.repl] λ=> (core/node)
#object[com.ericsson.otp.erlang.OtpNode 0x5afcf7e7 "clojang@spacemac"]
[clojang.component.repl] λ=> (core/mbox)
#object[com.ericsson.otp.erlang.OtpMbox 0x30cccc6c "com.ericsson.otp.erlang.OtpMbox@d8fa7fbe"]
[clojang.component.repl] λ=> (core/mbox-name)
"default"

Note that this example component makes use of the same JVM options that the Clojang agent does, as defined in the project.clj (:dev profile, :jvm-opts).

Donating ↟

A donation account for supporting development on this project has been set up on Liberapay here:

• https://liberapay.com/clojang/donate

You can learn more about Liberapay on its Wikipedia entry or on the service's "About" page.

License ↟

Copyright © 2018 The Clojang Project

Distributed under the Apache License Version 2.0.