Customizing the message in a jQuery validate custom rule

Question

I have a custom jQuery validate rule called fiftyCents() where there are two rules:

1. if the item is free, one can "buy" it for $0.00 or they can pay greater than $0.50.
2. if the item is NOT free, then they must pay at least the cost specified (stored in a hidden cachedValue input field).

So those are my two validation error messages. The problem I'm having in adding these to fiftyCents() is that I can only figure out how to evaluate it as true/false and if false, display a single message, eg, "Amount must be $0.00 OR greater than $0.50." .

The solution to the JSfiddle (code below too) appears to be to make a message object that could be part of the fiftyCents() function. However, I don't know how to return that along with evaluating true/false . Thoughts?

JS:

$('button').click(function(){
  $('form').validate().form();
});
$.validator.addMethod("fiftyCents", function(value) {

  var cachedValue=$('.purchaseModalAmtPaidCached').val();
  var value = $('.purchaseModalAmtPaid').val();
  var message="Amount must be $0.00 OR greater than $0.50.";
  if(cachedValue>0) message='Amount must be at least'+cachedValue+'.';
  return cachedValue<=value && (value==0 || (0.51<=value && value<=10000));
}, message);   

$.validator.classRuleSettings.purchaseModalAmtPaid = { fiftyCents: true };

HTML:

 <form>
  <input  class="purchaseModalPassword required" minlength="8" type="password"name="password" value="dddddddv" title="Please enter a valid password"  />
  <input type="text"  title="Amount must be $0.00 OR greater than $0.50" 
  class="required purchaseModalAmtPaid" name="amt_paid" value="" />
  <input type="hidden" class='purchaseModalAmtPaidCached required' name="AmtPaidCached" value="0.00" /> 
  <button type='button'>Buy</button>
 </form>​

Answer 1

Ok I answered my own question. What I ended up doing is splitting up the two rules into their own custom methods. I used an if/else before either custom method is invoked to determine which of the two should be followed.

Here's the JSFiddle and code below:

JS:

$('button').click(function(){
$('form').validate().form();

});

var params=$('.purchaseModalAmtPaidCached').val();                   
if(params>0){      
  $.validator.addMethod("AmountOrGreater", function(value, element, params) {
  console.log('amountOrGreater'+params[0]); 
  return params[0]<=value && (value==0 || (0.51<=value && value<=10000));
  }, $.validator.format("Amount must be at least {0}."));
  $.validator.classRuleSettings.purchaseModalAmtPaid = { AmountOrGreater: params };                       
} 
else{ 
  $.validator.addMethod("fiftyCents", function(value, element, params) {
  console.log('fiftyCents'+params[0]);
  return params[0]<=value && (value==0 || (0.51<=value && value<=10000));
  }, "Amount must be $0.00 OR greater than $0.50.");  
  $.validator.classRuleSettings.purchaseModalAmtPaid = { fiftyCents: params };  
} //else

HTML:

 <form>
  <input  class="purchaseModalPassword required" minlength="8" type="password" name="password" value="dddddddv" title="Please enter a valid password"  />
  <input type="text"   
class="required purchaseModalAmtPaid" name="amt_paid" value=""  /> 
  <input type="hidden" class='purchaseModalAmtPaidCached required' name="AmtPaidCached" value="0.00" /> 
  <button type='button'>Buy</button>
</form>​

Note: A key to the HTML cooperating with jQuery validate is that if you give your inputs a title='' attribute then that title will always be used, thus overriding the message in your custom rule. This is relevant in my case b/c there were two custom rules/messages and I'm not able to determine in advance of the HTML being rendered which one the user would see.