CODEWITHSUNDEEP
ruby-on-railsrubypolymorphic-associations
Teej
Teej

Reputation: 12873

undefine method following Railscasts 154

I am quite the newbie here.

I have been following Railscasts 154 but when I try submitting a comment, I get this error:

undefined method `classify' for nil:NilClass

I little debugging has pointed me to this:

(rdb:5) name =~ /(.+)_id$/
0

debugging name comes up with micropost_id but $i is somehow returning nil.

  private
  def find_commentable
    params.each do |name, value|
      if name =~ /(.+)_id$/
        debugger
        return $i.classify.constantize.find(value)
      end
    end
    nil
  end

How do I get past this problem?

Upvotes: 0

Views: 422

Answers (2)

Jorge Israel Peña
Jorge Israel Peña

Reputation: 38576

This line:

return $i.classify.constantize.find(value)

should be:

return $1.classify.constantize.find(value)

$1 is a global variable storing the first matched group from the regular expression match result.

Upvotes: 1

Max Chernyak
Max Chernyak

Reputation: 37357

Looks like $i.classify should've been $1.classify. In ruby $1, $2, ... are global variables which hold the value of the last regexp-matched group. In this case $1 will contain whatever is in parenthesis in your regexp: /(.+)_id$/.

In your case $i is nil, therefore you get error trying to call classify on nil.

Upvotes: 1

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