From: Brian Candler <b.candler@...>
Date: 2009-05-29T17:35:54+09:00
Subject: Re: Defining a method to select values from a hash.

You want foo['bar'] and foo.bar to be the same thing, like in 
Javascript? In that case you need to modify Hash, not String. Below is 
some code which does that.

---- 8< ----
# Extend a Hash with this module to get semantics of a Javascript 
object:
# me.foo is the same as me['foo']
module JSObjectMixin
  def method_missing(meth,*rest,&blk)
    key = meth.to_s
    if key[-1] == ?=
      self[key[0..-2]] = rest.first
    else
      self[key]
    end
  end
end

def extend_jsobject(tree)
  case tree
  when Hash
    tree.extend JSObjectMixin
    tree.each do |k,v|
      extend_jsobject(v)
    end
  when Array
    tree.each do |v|
      extend_jsobject(v)
    end
  end
end

errors = [{"suggestions"=>{"option"=>["really", "ready", "real", 
"relay",
  "realty"]}, "precontext"=>"I'm", "type"=>"spelling", 
"string"=>"realy",
  "description"=>"Spelling"}, {"suggestions"=>{"option"=>["weather",
  "whether"]},
  "url"=>"http://service.afterthedeadline.com/info.slp?text=wether",
  "precontext"=>"this", "type"=>"spelling", "string"=>"wether",
  "description"=>"Did you mean..."}]
extend_jsobject(errors)

errors.each { |error| p error['string'] }
errors.each { |error| p error.string }
---- 8< ----

Another option would be to walk your results structure and replace each 
Hash with an OpenStruct (see ostruct.rb in the standard library). 
However, that would _only_ allow error.string, not error['string']

> The other problem I'm having with the way I'm doing it now is that
> calling .errors.each when there's only one error sent back gives me a
> "can't convert String into Integer" error.

Simple solution:

   Array(atd.errors).each { ... }

If atd.errors is already an Array this does nothing; if it isn't, then 
it is wrapped in a one-element array.

Better solution: If this is using XML::Simple internally, there's an 
option you can give it to return arrays always, even when there's only a 
single instance (or I believe you can tell it to do this for specific 
tags). I can't remember offhand what that option is, but you should be 
able to find it. Then see if the library you're using allows that option 
to be passed through.

HTH,

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