title: Undefined local variable or method when accessing from controller to helper methods
body: <p>I created a controller which called 'internal releases'.</p>
  
  <p>I want to check that the multi-select objects contains at least one selection each.</p>
  
  <p>In my controller I have:</p>
  
  <pre><code>class InternalReleasesController &lt; ApplicationController
  
    def show
  
      if params[:run].nil?
        logger.error "Attempt to get trend result without going through the internal_releases_trend_selection_url"
        flash[:no_arguments] = 'You have tried accessing trend results without selecting parameters.'
        redirect_to internal_releases_trend_selection_url
  
      else 
        all_options = Array.new(params[:run][:category_id])
        missing_selections = validate_arguments params[:run]
  
        all_options = Array.[]params[:run][:category_id]
  
        logger.debug "all_options is: #{all_options.class}"
      end
  
    end
  end
  </code></pre>
  
  <p>I created a simple helper method:</p>
  
  <pre><code>module InternalReleasesHelper
  
    def validate_arguments multiselect_hash
  
      answer = Array.new
  
      multiselect_arr.each do |key, val_arr|
        if val_arr.length==1  # therefore, no selection made in this multiselect- the first arg will always be ""
          answer &lt;&lt; key
        end
      end
      answer
    end
  end
  </code></pre>
  
  <p>For some reason I get:</p>
  
  <pre><code>undefined method `validate_arguments' for #&lt;InternalReleasesController:0x007faf08bf9f78&gt;
  </code></pre>
  
  <p>What might cause this?</p>