title: Rails: Is it possible to check if a named scope is valid for a given active record?
body: <p>I'm Using Ruby 1.8.7-p374 and Rails 2.3.18. (Yeah, I know, we're working on it.)</p>
  
  <p>I'm considering dynamically passing a named scope to be used as a condition for an ActiveRecord. Is it possible to check to see if a passed string is a valid named scope for the record?</p>
  
  <p>For Example:</p>
  
  <p>If I have a named scope called :red defined for Car</p>
  
  <pre><code>named_scope :red, :condition =&gt; ["color = ?", "red"]
  </code></pre>
  
  <p>Then is there some function where I could do</p>
  
  <pre><code>Car.some_function("red")   # returns true
  Car.some_function("blue")  # returns false
  </code></pre>
  
  <p>Thanks in advanced.</p>