jQuery Validation - Select Multidimensional Array at least 1

Answer 1

To mandate that at least one out of these select elements are selected, you would use the require_from_group method which is part of the additional-methods.js file.

$('#myform').validate({
    // other options,
    rules: {
        "quantity[adult][seat_a]": {
            require_from_group: [1, ".group-required"]
        },
        "quantity[adult][seat_b]": {
            require_from_group: [1, ".group-required"]
        },
        "quantity[adult][seat_c]": {
            require_from_group: [1, ".group-required"]
        }
    },
    groups: {
        myGroup: "quantity[adult][seat_a] quantity[adult][seat_b] quantity[adult][seat_c]"   
    }
});

This will create a simultaneous & identical error message on all three select elements. Use the groups option to combine these into one and the errorPlacement option to place the resulting message into your layout.

Important: You also need the value of the default option of every select to be empty. Otherwise, the plugin thinks 0 is the user's selection and nothing will be validated.

<select name="quantity[adult][seat_a]" class="group-required">
    <option value="">0</option>
    ....

OR...

<select name="quantity[adult][seat_a]" class="group-required">
    <option value="">Please select...</option>
    <option value="0">0</option>
    ....

---

EDIT:

If you have a huge number of elements and do not wish to declare them individually within .validate(), then use the .rules('add') method within a jQuery .each().

$('#myform').validate({
    // other options,
});

$('.group-required').each(function() {
    $(this).rules('add', {
        require_from_group: [1, '.group-required']
    });
});

Working DEMO: http://jsfiddle.net/n1z0Lufw/

Additionally, using the groups option to consolidate error messages, again without having to declare each field name manually...

var names = "";
$('.group-required').each(function() {
    names += $(this).attr('name') + " ";
});
names = $.trim(names);

$('#myform').validate({
    // other options,
    groups: {
        myGroup: names
    }
});

$('.group-required').each(function () {
    $(this).rules('add', {
        require_from_group: [1, '.group-required']
    });
});

DEMO 2: http://jsfiddle.net/scmuxq53/