Variable number of arguments for methods called with "send"

Hi there,

I have a (soooo) dummy class :

# --

class Main < XXXXX

  def time
    'Il est ' + Time.now.to_s
  end

  def salut
    ['salut', 'les', 'musclés']
  end

  def test_with_args(arg1, arg2)
    [arg1, arg2]
  end

  def test_with_multiple_args(*args)
    args
  end

end

# /--

In a configuration file, I have the name of the methods and their
arguments if they need some:

# --

config:
  aff_bonjour: __SALUT
  aff_temps: __TIME
  tab_toto: __TEST_WITH_ARGS 'toto', 53

# /--

In another script, I get back the config file and try to call the
lethods in order to stack their results.
In order to do that, I wrote something like:

# --

vars = {}
config = YAML::load('config.yml') # the config file described previously
@name = 'Main' # got from config file
obj = Object.const_get(@name).new # Create the object
config.each do |key, value|
  if value =~ /^__(.+)/ and !obj.nil?
    tmp = value.gsub(/^__/, '').downcase.split(' ')
    method = tmp[0] # get the method name
    tmp.delete_at 0 # delete method name from the array
    tmp.map do |e|
      e.gsub!(/,/, '') # clean up remaining args
      e.strip!
    end
    vars[key.to_s] = obj.send(method.to_sym) if obj.respond_to? method
  else
    vars[key.to_s] = value
  end
end

# /--

Here is the small description

1. After preparing the object, I check every line of my config
2. if it is a method (begins by '__'), I get the optional args

    e.g: "tab_toto: __TEST_WITH_ARGS 'toto', 53"
             "test_with_args" is the method
             'toto' and 53 are the args

3. I call the method by invoking "obj.send(method.to_sym)"
4 (back to 2) and if it is not a method, I just copy the static value
to my "vars" hash

And here is my problem :

for a method that does not take any argument (like "time" or "salut"),
there is no problem, it works like a charm.

But if I want to call a method with arguments, I am stuck because I do
not know how many arguments it needs and what is the "kind" of arguments
(can be "static arguments" - arg1, arg2 - or VARGS - *args - )

How can I call a method with a dynamic array (even empty) to cover all
the different kind of methods of my "Main" class ?

Or is there any other solution for that ?

I do not know if those explanations are clear enough, tell me if not.

Thank you for your potential help,
Regards,

Pierre

···

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Posted via http://www.ruby-forum.com/.

Pierre Lecocq wrote:

But if I want to call a method with arguments, I am stuck because I do
not know how many arguments it needs and what is the "kind" of arguments
(can be "static arguments" - arg1, arg2 - or VARGS - *args - )

There is no difference between those cases.

args =
send(:foo, *args)
# same as: send(:foo)

args = ["abc"]
send(:foo, *args)
# same as: send(:foo, "abc")

args = ["abc","def"]
send(:foo, *args)
# same as: send(:foo, "abc", "def")

HTH,

Brian.

···

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Posted via http://www.ruby-forum.com/\.

Thanks a lot Brian.
In fact, I didn't put the star before my args array.
That is why it crashed when the method does not take arguments.

Thanks again !

Brian Candler wrote:

···

Pierre Lecocq wrote:

But if I want to call a method with arguments, I am stuck because I do
not know how many arguments it needs and what is the "kind" of arguments
(can be "static arguments" - arg1, arg2 - or VARGS - *args - )

There is no difference between those cases.

args =
send(:foo, *args)
# same as: send(:foo)

args = ["abc"]
send(:foo, *args)
# same as: send(:foo, "abc")

args = ["abc","def"]
send(:foo, *args)
# same as: send(:foo, "abc", "def")

HTH,

Brian.

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Posted via http://www.ruby-forum.com/\.