ruby on rails - When to use Helpers vs Model

Question

I'm new to Rails and just wondering when I should put code into a Helper as opposed to putting the code into the Model.

Is there a 'rule of thumb' so to speak for this?

Answer 1

Use helpers if you're working in a view (template) and you need to build a complex bit of HTML such as a <table>. Or, if you want to change some presentation data that's not connected to the database.

def truncate_html( html, options = {} )
  options[:length] = 35 unless options[:length]
  truncate( strip_tags( html ), options )
end

Use models when you're working with database objects, and you want to simplify the business logic.

  def one_day?
    start_date.to_s[0,9] == end_date.to_s[0,9]
  end  

Here's Helpers in the guides: http://guides.rubyonrails.org/form_helpers.html

And here's Models: http://guides.rubyonrails.org/active_record_querying.html