JQuery Validate Plugin - How to create a simple, custom rule?

Question

How do you create a simple, custom rule using the JQuery Validate plugin (using addMethod) that doesn't use a regex?

For example, what function would create a rule that validates only if at lease one of a group of checkboxes is checked?

Answer 1

You can create a simple rule by doing something like this:

jQuery.validator.addMethod("greaterThanZero", function(value, element) {
    return this.optional(element) || (parseFloat(value) > 0);
}, "* Amount must be greater than zero");

And then applying this like so:

$('validatorElement').validate({
    rules : {
        amount : { greaterThanZero : true }
    }
});

Just change the contents of the 'addMethod' to validate your checkboxes.

Answer 2

Thanks, it worked!

Here's the final code:

$.validator.addMethod("greaterThanZero", function(value, element) {
var the_list_array = $("#some_form .super_item:checked");
return the_list_array.length > 0;
}, "* Check at least one checkbox");

Answer 3

Hi edward, I need this functionality as well, but my code isn't executing... Can you post a more complete example of you code?

I don't know where to write the $.validator.addMethod, should that be outside of the form.validate code?

I currently have:

jQuery.validator.addMethod("at_least_one_cat_selected", function(value, element) { var the_list_array = $("ul#list_all_categories li input:checked"); return the_list_array.length > 0; }, "Please specify the correct domain for your documents");

and then inside the validation call:

rules: { list_all_categories: {at_least_one_cat_selected: true} },

but that isn't working. Please note: list_all_categories is the name of the that contains all checkboxes?

Answer 4

$(document).ready(function(){
$.validator.addMethod("uniqueUserName", function(value, element) {
      $.ajax({
          type: "POST",
           url: "http://"+location.host+"/checkUser.php",
          data: "checkUsername="+value,
          dataType:"html",
       success: function(msg)
       {
          // if the user exists, it returns a string "true"
          if(msg == "true")
             return false;  // already exists
          return true;      // username is free to use
       }
     })
}, "Username is Already Taken");
   $("#regFormPart1").validate({
username: {
      required: true,
       minlength: 8,
       uniqueUserName: true
       },
 messages: {
username: {
      required: "Username is required",
       minlength: "Username must be at least 8 cheractors",
       uniqueUserName: "This Username is taken already"
      }
    }
 }); 

Answer 5

########################
## In validation Rules #
########################
regemail: {
    required: true,
    email: true,
    remote: {
        url: "checkmail.php"
    }
},

#####################
## In message Rules #
#####################
regemail: {
    required: "Email is required",
    email: "Invalid Format",
    remote: ""
}

###########################
## Modify Jquery Validate #
###########################
#Search For:
var valid = response === true;
if ( valid ) {

#Change To:
var valid = response.data;
if ( !valid ) {
   valid = true;

#Search For
} else {
   var errors = {};

#Change To
} else {
   valid = false;
   var errors = {};


#Search For:
errors[element.id] = previous.message = response || validator.defaultMessage( element, "remote" );

#Change To:
errors[element.id] = response.data || validator.defaultMessage( element, "remote" );

#PHP Returns JSON return ($m == $m) ? false : 'Email Already Registered'