title: alias_attribute method in rails model not working when using the "record[:col]" syntax
body: <p>I'm doing some backend work (xls-scraping) for an accounting/finance rails app, and I'm wanting to allow a table to accept multiple accounting entity tags for the same column</p>
  
  <p>So I'm using the <code>alias_attribute</code> method in my models to accomplish this</p>
  
  <pre><code>class DouglasAudit
    #...
    alias_attribute :new_alias_name, :actual_column_name
    alias_attribute :net_rental_income, :net_rental_revenue
    #...
  end
  </code></pre>
  
  <p>Aliasing like this is very useful to me because I can scan these <strong>dreadfully</strong> diverse spreadsheets, searching for metatag matches which are then converted <em>directly</em> into symbols to be called on the respective model to store their respective data like so (pseudo-codey, the actual code is much more dense):</p>
  
  <pre><code>spreadsheet[0] = [Roo::Excel(filename), property_id]
  rows_to_scrape.each do |rownum|
    rowtag = spreadsheet[0][0].cell(rownum, "A")
    if @tags_wanted.include?(rowtag)
      d = DouglasAudit.find_by_ssid(spreadsheet[0][1])
      tagvar = variableize(rowtag).to_sym # 'variableize' converts "Hello World" into "hello_world", etc
      d[tagvar] = spreadsheet[0][0].cell(rownum, "E")
      d.save
    end
  end
  </code></pre>
  
  <p>If I had an alias for the <code>net_rental_revenue</code> mentioned above (the 2nd named variable), when :net_rental_income is passed into the DouglasAudit instance (<code>d[:net_rental_income]</code>) nothing happens. Due to the nature of the ar_object[:col] method no error is thrown but the data is not saved.</p>
  
  <p>I really like being able to use the ar_object[:col] method for dynamic programming. What is going on here to trip this up and what are some good ways around it? </p>
  
  <p>-- I am trying to avoid using eval() but answers using eval are still technically valid albeit less secure</p>