Question

I’m following this tutorial – http://communityguides.heroku.com/articles/9 -app/controllers/admin_controller.rb

Stuck on a “can’t convert nil into String” error with the following block of code.

# freeze state 
@article.freezebody = @article.title + "\n\n" + @article.teaser + "\n\n" + @article.body + "\n\n" + @article.version + "\n\n" + @article.changelog 
@article.accepted = Time.now 

Is this a regex issue? I don’t even know where to start.

Answer 1

One ore more of your attributes is nil, and this:

nil + ''

will give you the exception you’re seeing.

To concatenate those attributes, minus any that might be nil (shortened for readibility):

[@article.title, @article.teaster].compact.join("\n\n")

compact removes all nil objects from the array.