cx_config_plugin

CX plugin to parse yaml files and provide the values to CLIPS

README

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")
)