jQuery Validation plugin specify compound rules to use in validate rules argument

Question

The jQuery validation plugin (jquery.validate.js) supports the method addClassRules(). This allows me to do something like this:

$.validator.addClassRules({
  birthdate: {
    date: true,
    notFuture: true,
    notBefore1900: true
  }
});

where the notFuture and notBefore1900 are methods I've previously specified with calls to .addMethod().

This allows me to use that by specifying the class: <input class="birthdate" name="foo" /> and it validates just fine, displaying the appropriate validation error message based on the specific method that triggered the invalid state.

My question is how do I do such compound rules and specify them as part of the rules arguments to the validate() method? I want to be able to do this:

$('#myForm').validate({
  rules: {
    foo: 'birthdate'
  }
});

Sadly while validation methods themselves can be represented either as class names or as explicit rules in the arguments like

rules: {
  foo: 'date'
}

one cannot do the same with class rules; it expects the rules arguments to validate() to be a method and not a class rule.

I could do something like:

var reusableRule = {
  date: true,
  notFuture: true,
  notBefore1900: true
};
...
$('#myForm').validate({
  rules: {
    foo: reusableRule
  }
});

but I'd prefer to keep things contained within the plugin itself rather than invading the global scope. I could do something like this

$.validator.customRules = {
  birthdate: {
    date: true,
    ...
  }
}

but then it looks ugly (or at least inconsistent with the syntax of the other rules items):

$('#myForm').validate({
  rules: {
    foo: $.validator.customRules.birthdate
  }
});

Also, I run the risk of a later version of the plugin specifying something like customRules which would cause a collision.

For now I think I'll keep them in the global scope, but if anyone has a cleaner way (or if there's a 'right way' that I missed when parsing the documentation) please share. Thanks :)

Answer 1

Quote OP:

"My question is how do I do such compound rules and specify them as part of the rules arguments to the validate() method?"

• The .addClassRules() method creates compound rules that you can only declare inline as a class.

• If you want a rule you can declare within .validate(), then you would use the addMethod method.

• Alternatively, compound rules can be assigned to variables that can be used within .validate().

Otherwise, I really don't see how "invading the global scope" is any kind of a problem worry about. Either you'll use the options as provided, or create your own. I don't see how you could ever customize any option for any plugin without some invasion of "the global scope".

---

Quote OP:

"Also, I run the risk of a later version of the plugin specifying something like customRules which would cause a collision"

I think that's highly unlikely, and probably impossible. Even when you create a custom method with the .addMethod() method using the same name as an existing method, only the second instance is used... that instance would be your custom rule since it's defined after the plugin's methods are included.

---

You could also combine your custom compound rules into new sets of compound rules using the jQuery extend() method.

Here is some reference: https://stackoverflow.com/a/9056425/594235