Writting custom rule for arara 4.0

Question

Motivation: I would like to copy a file foo.bar to \jobname.bar before every pdflatex run. So I thought, I could modify an existing arara rule.

I wanted to try the hello.yaml rule for arara from this answer: https://tex.stackexchange.com/a/119246/36296

!config
# Hello world
# author: Chris Hughes, Paulo Cereda
# last edited by: cmh, June 14th 2013
# requires arara 3.0+
#
# Sample usage: 
#
# % arara: hello
# % arara: hello: {name: A.Ellett}
#
# This rule is really just a shortcut for commands like the following
#
#   hello
# or
#   hello A.Ellett
#
identifier: hello
name: hello
commands: 
- <arara> bash -i -c hello @{name}
arguments: 
- identifier: name
  flag: <arara> @{parameters.name}
  default: "world"

But if I try to run this rule with

% arara: hello

in my .tex file, I get the following error message:

I have spotted an error in rule 'hello' located at
'<path to arara>/rules'. I could not parse the rule,
something bad happened. Apparently, the provided YAML file is
invalid. I will do my best to help you in any way I can. There
are more details available on this exception:
DETAILS ---------------------------------------------------------
Cannot create property=commands for
JavaBean=com.github.cereda.arara.model.Rule@55a1c291
 in
'reader', line 1, column 1:
    !config
    ^
No single argument
constructor found for class
com.github.cereda.arara.model.RuleCommand
 in 'reader', line 21,
column 1:
    -   <arara> bash -i -c hello @{name}
    ^

(I replaced <path to arara> in the above message, as the original one contained my user name; I have other custom .yaml files for arara in the same location which work flawlessly)

The bash function itself seems to work. If I do

bash -i -c hello sam

within a terminal, I get

Hello, sam!

as expected.

I am using arara 4.0. Any ideas what might be wrong?

Answer 1

I think you actually want something like this:

!config
# Hello world
# author: Chris Hughes, Paulo Cereda
# last edited by: cmh, June 14th 2013
# requires arara 3.0+
#
# Sample usage: 
#
# % arara: hello
# % arara: hello: {name: A.Ellett}
#
# This rule is really just a shortcut for commands like the following
#
#   hello
# or
#   hello A.Ellett
#
identifier: hello
name: hello
commands: 
- command: <arara> bash -i -c hello @{name}
arguments: 
- identifier: name
  flag: <arara> @{parameters.name}
  default: "world"

Answer 2

Don't you want something like this?

!config
# Hello world
# author: Chris Hughes, Paulo Cereda
# last edited by: cmh, June 14th 2013
# requires arara 3.0+
#
# Sample usage: 
#
# % arara: hello
# % arara: hello: {name: A.Ellett}
#
# This rule is really just a shortcut for commands like the following
#
#   hello
# or
#   hello A.Ellett
#
identifier: hello
name: hello
command: <arara> bash -i -c hello @{name}
arguments:
- identifier: name
  flag: <arara> @{parameters.name}
  default: "world"
# vim: set nospell: