title: Change priority of Custom validations in rails model
body: <p>I have implemented validations in a dependent manner, like if start_date format is invalid so i don't want to run other validation on start_date. </p>
  
  <pre><code> validates_format_of :available_start_date, :with =&gt;  /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}((((\-|\+){1}\d{2}:\d{2}){1})|(z{1}|Z{1}))$/, :message =&gt; "must be in the following format: 2011-08-25T00:00:00-04:00"
  </code></pre>
  
  <p>This checks for a specific format and then i have custom validation methods called from which should run later. </p>
  
  <pre><code>def validate
    super
    check_offer_dates
  end
  </code></pre>
  
  <p>I have used self.errors["start_date"] to check if the error object contains errors, it should skip the other validations on same parameter if it's not empty.</p>
  
  <p>But the problem is def validate is called first and then the validates_format_of. How can i change this so that the flow can be achieved.</p>