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Module: bract.cli

Clojars coordinates: [bract/bract.cli "0.6.0-0.1.0"]

Context keys

Context key Value Description
:bract.cli/config-required? Boolean Is config file required to be specified?
:bract.cli/command String CLI command to execute
:bract.cli/cmd-args String vector CLI command arguments
:bract.cli/app-commands Command map Commands, e.g. {"run" {:doc "Run app" :handler myapp.core/run}}
:bract.cli/pre-inducers Inducer list Inducers to run before parsing CLI args


All inducers exposed by bract.cli are in the namespace bract.cli.inducer. A summary is below:

Inducer function Input context keys Output context keys Description
merge-commands :bract.cli/app-commands :bract.cli/app-commands Add app commands
parse-args :bract.cli/cli-args :bract.core/verbose? Parse CLI args
execute-command :bract.cli/command depends on the command Execute command

Entry points

This module provides the following entry points for CLI integration.

Provided Java main() method

The namespace bract.cli.main is generated as a Java class, hence the function bract.cli.main/-main can serve as a Java main() method.

Leiningen users can put the following in project.clj under the uberjar profile to use this entry point:

:profiles {:uberjar {:aot [bract.cli.main]
                     :main ^:skip-aot bract.cli.main}}

After updating project.clj as mentioned above , the lein uberjar command would produce a standalone JAR file that you may execute using the command java -jar <appname>-<version>-standalone.jar - it invokes the main method.

Application’s own main() method

When you want to customize the initial context or you want to extend the CLI commands supported by the application, you would want to call the bract.cli.main/trigger function with context as the argument. For example, if you want to support an additional command “status” you could write a namespace as follows:

(ns myapp.main
    [bract.cli.config :as cli-config]
    [bract.cli.main   :as cli-main])

(defn find-status [context]

(defn -main [& args]
  (cli-main/trigger {:bract.core/cli-args    args
                     :bract.cli/app-commands (assoc cli-config/default-commands
                                               "status" {:doc "Find status of XYZ"
                                                         :handler find-status})}))

You can replace the namespace bract.cli.main with myapp.main in the steps listed in the sub-section above and it would all work using the new entry point.

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