title: CakeDC Search Plugin producting duplicate conditions
body: <p>So I'm using the (totally awesome) Cake DC Search plugin. Among other things, I want to have a 'min' and 'max' input, and search for records where 'amount' is within 'min' and 'max', if both are set, or greater-than/less-than min/max if only one is set.</p>
  
  <p>I've got it working - the only problem is that the condition is being included twice in the SQL query. It's pretty obvious why... here's my model code:</p>
  
  <pre><code>public $filterArgs = array(
      'range_min' =&gt; array('type' =&gt; 'query', 'method' =&gt; 'findByAmountRange'),
      'range_max' =&gt; array('type' =&gt; 'query', 'method' =&gt; 'findByAmountRange'),
      // Other rules go here
  );
  
  
  public function findByAmountRange($data = array()) {
      // Returns a condition something like 'Model.amount BETWEEN 1 and 100'
  }
  </code></pre>
  
  <p>So because both the 'range_min' and 'range_max' keys of $filterArgs both use the same method (findByAmountRange), then the condition is being included twice.</p>
  
  <p>So, there are three solutions:</p>
  
  <ol>
  <li><p>Don't worry about it, let the condition be there twice</p></li>
  <li><p>Create a instance variable in the model, like findByAmountRangeHasBeenCalled, and set it true the first time the method is called, so we know not to call it again in future</p></li>
  <li><p>Find a more elegant solution. Does the Search plugin have any way to deal with this? Can you set it to make two fields share a common filterArgs method, so that it only gets called once?</p></li>
  </ol>
  
  <p>Thanks in advance.</p>
  
  <p>PS - I know the test cases for the Search Plugin include a 'make range condition' example, but that's not what I want - I want two fields, with the user able to input into both of them.</p>