Question

I have a MongoMapper model and am trying to convert a comma-delimited string into an Array to be stored.

The main problem is that a string such as tags = "first,second,third" is not getting converted to an array in the database like ["first","second","third"]. Instead it is going in as ["first,second,third"].

There are some other strange things going on as well:
1) In preen_tags I have to include the unless tags.nil? after every line
2) in preen_tags, using the debugger tags returns nil

Here is my model

class Template
  include MongoMapper::Document
  validate :validate_tags
  after_validation :preen_tags

  key :template_id,     ObjectId

  key :title,           String
  key :description,     String

  key :tags,            Array

  timestamps!

  def validate_tags
    errors.add_to_base "You Must Enter At Least 1 Tag." if tags.blank? 
  end


  def preen_tags
    #return if tags.nil?     #why doesn't this work??
    #only alphanumeric chars allowed, except hyphens and commas
    tags = tags[0] if tags.is_a?(Array)
    tags = tags.gsub(/[^0-9a-z\-\,]/i, '') unless tags.nil?
    #convert spaces to hyphens
    tags = tags.gsub(/\s/, '-') unless tags.nil?
    tags = tags.split(",") unless tags.nil?
  end

end

Answer 1

Looks like converting the String to an Array inside the controller before passing it to the Model has solved things.