Exporting CSV data from Rails

Question

I'm working to export CSV data from Rails. I'm following the tutorial here: http://railscasts.com/episodes/362-exporting-csv-and-excel?view=asciicast

In my controller I have:

  def show
    # @company is being provided correctly.
    @groups = @company.groups
    render text: @groups.to_csv
  end  

In my group.rb model:

  def self.to_csv
    Rails.logger.info "Hello World"
    CSV.generate do |csv|
      csv << column_names
      all.each do |product|
        csv << product.attributes.values_at(*column_names)
      end
    end
  end

The issue is the browser is outputting just the following:

#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#,#

The model method appears to be being ignored, even after a Rails restart. What's wrong here?

Answer 1

The to_csv is a class method. Meaning its meant to be called like Group.to_csv. You might want to change the method signature to something like Group.to_csv(groups) instead.

 def self.to_csv(groups)
    Rails.logger.info "Hello World"
    CSV.generate do |csv|
      csv << column_names
      groups.each do |product|
        csv << product.attributes.values_at(*column_names)
      end
    end
  end

Then in show

  def show
    # @company is being provided correctly.
    @groups = @company.groups
    render text: Group.to_csv(@groups)
  end