Component Change Log

1.2.x series

Version 1.2.0 released on October 25, 2025

• Add implementation of java.io.Closeable on SystemMap, so .close on a system calls component/stop. See #76.

  This allows use of with-open on systems, for example (with-open [system (start system)] ...) in tests.

  Fulfulls a similar purpose as the various with-* macros proposed in #6, #7, and elsewhere. Also inspired by a conversation with Ian Fernandez at Clojure South 2025.

1.1.x series

Version 1.1.0 released on February 26, 2022

• Add subsystem (motivated by conversations in #69 and elsewhere)

1.0.x series

Version 1.0.0 released on March 7, 2020

• Modify Clojure dependency to be :scope "provided" to prevent spurious warnings when overridden by a later version. Note that this also prevents warnings when overridden by an earlier, incompatible version of Clojure. Component since version 0.3.0 requires Clojure 1.7.0 or later. (commit 5af4ad06; reported by Dave Yarwood in #65).

• Update 'dependency' library to version 1.0.0

0.4.x series

Version 0.4.0 released on December 30, 2018

• Add :extend-via-metadata to Lifecycle protocol for Clojure 1.10 extend-via-metadata. Backwards-compatible with earlier Clojure versions (commit 7824f551; suggested by Joe Lane in #62).

• Not backwards-compatible with ClojureScript versions before ClojureScript 1.10.516 (reported by Ryan Schmukler in #63).

0.3.x series

Version 0.3.2 released on December 12, 2016

• Fix incorrect base class for extending Lifecycle (commit 69e62854; reported by Tim Pote)

Version 0.3.1 released on November 28, 2015

• Fix incorrect values for ex-data keys in missing-dependency error (reported by Howard Lewis Ship at #40)

Version 0.3.0 release on September 18, 2015

• API-compatible with 0.2.x

• Minimum Clojure version 1.7.0 for Conditional Read

• Added ClojureScript support via Conditional Read

0.2.x series

Version 0.2.3 released on March 3, 2015

• More-specific error message when a component returns nil from start or stop (commit fb891500; reported by James Gatannah at #17)

Version 0.2.2 released on September 7, 2014

• System maps print as #<SystemMap> to avoid trying to print huge objects in the REPL (reported by Howard Lewis Ship at #9)

• Add error helpers ex-component? and ex-without-components

• Change :component-key to :system-key in ex-data maps: breaking change for code which depended on the value of :component-key

• Add :system-key to ex-data map from try-action

• Minor changes to exception message strings

• Leiningen profiles / aliases to test on all supported Clojure versions

Version 0.2.1 released on December 17, 2013

• Add generic system-map

• More descriptive messages on exceptions

• Add arity-1 versions of start-system and stop-system that default to all keys in the system

Version 0.2.0 released on November 20, 2013

• API compatible with 0.1.0

• Some exception messages changed

• Added default no-op implementation of Lifecycle protocol

• Added update-system and update-system-reverse

• Redefined start-system and stop-system in terms of these

• stop-system now assoc's dependencies just like start-system

0.1.x series

Version 0.1.0 released on October 28, 2013