From: Rick DeNatale <rick.denatale@...>
Date: 2009-04-07T06:12:23+09:00
Subject: Re: Method missing and arrays as arguments..

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On Mon, Apr 6, 2009 at 4:35 PM, Kyle Schmitt <kyleaschmitt@gmail.com> wrote:

> How do you go about passing arrays as arguments to something like
> method_missing?  I've got a method that takes an array as an argument,
> but calling it via method_missing is proving problematic.  How do you
> deal with arrays in these situations?
>
>  def table_row(values)
>    # values is the list of items in the table row
>    #....
>  end
>
>  def method_missing(method,*args)
>    if respond_to?method.to_s[/^add_([^$]+)/,1]
>        @data<<method(method.to_s[/^add_([^$]+)/,1]).call(*args)
>    else
>      super method_missing(method,*args)
>    end
>  end



I'm not sure exactly what you are trying to do, I'm guessing that if you
send add_table_row(some_array) to an instance, the method_missing will call
table_row and add the result to @data.

The problem isn't the array argument, it's what you are doing in the true
leg of the if.

The first argument to method_missing is not a method, but a symbol.  You are
converting this symbol to a string, stripping off add_ from the beginning
and they trying to call the string, which ain't gonna work.

Instead you want to use send:

class SomeClass
  attr_reader :data

  def table_row(values)
    # values is the list of items in the table row
    #....
    values
  end

  def method_missing(symbol,*args)
    without_add = symbol.to_s[/^add_([^$]+)/,1]
    if respond_to? without_add
        @data ||= []
        @data<< send(without_add, *args)
    else
      super method_missing(method,*args)
    end
  end
end

sc = SomeClass.new
sc.add_table_row([1,2,3])
sc.data # => [[1, 2, 3]]

I used lazy initialization to initialize @data, assuming that this is
vaguely what you are after.

-- 
Rick DeNatale

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