YAML Configuration Plugin

Source code on GitHub.

This plugin provides the ability to parse YAML files into CLIPS facts.

Configuration

This plugin has no specific configuration.

Features

This plugin adds deftemplates and custom functions as listed below.

Facts

; Asserted by the config-load function for each configuration value in the parsed yaml file.
(deftemplate confval
  (slot path (type STRING))
  (slot type (type SYMBOL) (allowed-values FLOAT UINT INT BOOL STRING))
  (slot value)
  (slot is-list (type SYMBOL) (allowed-values TRUE FALSE) (default FALSE))
  (multislot list-value)
)

Functions

; Load all config values from a file (absolute path) given a prefix and store them into (confval) facts.
; The prefix can be used to restrict the loaded values to a prefix
; Use / for nesting, e.g., foo/bar for only retrieving values under bar in this example:
;  foo:
;    bar:
;      ...
; For / inside of keys, wrap the whole key by single quotes ', e.g., '/foo'/bar if the key is "/foo" instead of "foo".
(config-load ?file ?prefix)

Usage Example

A minimal working example is provided by the cx_bringup package. Run it via:

ros2 launch cx_bringup cx_launch.py manager_config:=plugin_examples/config.yaml

It loads the used environment manager configuration file into CLIPS and prints the corresponding facts.

Configuration

File cx_bringup/params/plugin_examples/config.yaml.

clips_manager:
  ros__parameters:
    environments: ["cx_config"]
    cx_config:
      plugins: ["ament_index", "config", "files"]
      log_clips_to_file: true
      watch: ["facts", "rules"]

    ament_index:
      plugin: "cx::AmentIndexPlugin"
    config:
      plugin: "cx::ConfigPlugin"
    files:
      plugin: "cx::FileLoadPlugin"
      pkg_share_dirs: ["cx_bringup"]
      load: [
        "clips/plugin_examples/config.clp"]

Code

File cx_bringup/clips/plugin_examples/config.clp.

(defrule load-bringup-config
  (not (confval))
  =>
  (bind ?share-dir (ament-index-get-package-share-directory "cx_bringup"))
  (bind ?file (str-cat ?share-dir "/params/plugin_examples/config.yaml"))
  (printout green "Loading from file " ?file crlf)
  ; test loading of sequence
  (printout green " 1. Prefix leading to environments (sequence): " crlf)
  (config-load ?file "'/**'/ros__parameters/environments")
  ; test loading of map
  (printout green " 2. Prefix leading to environment config (map):" crlf)
  (config-load ?file "'/**'/ros__parameters/cx_config/")
  ; test loading of value
  (printout green " 3. Prefix leading to config plugin string (scalar):" crlf)
  (config-load ?file "'/**'/ros__parameters/config/plugin")
)

Changelog for package cx_config_plugin

0.1.3 (2025-08-06)

• 0.1.3
• Contributors: Tarik Viehmann

0.1.2 (2025-07-16)

0.1.1 (2025-07-11)

• project: prepare for first ros2 release
• Contributors: Tarik Viehmann