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Updating ‘validate-one-required’ in Prototype.js Dexagogo validation

June 18th, 2008

Dexagogo Validation ala prototype.js Hasn’t been updated for over a year now, but there was one validation that always bugged me:

validate-one-required*

*To use the validate-one-required validator you must first add the class name to only one checkbox/radio button in the group (last one is probably best) and then place all the input elements within a parent element, for example a div element. That way the library can find all the checkboxes/radio buttons to check and place the validation advice element at the bottom of the parent element to make it appear after the group of checkboxes/radio buttons.

The problem with this? As coded, all inputs must be direct descendants of the same parent. Browsers, however, do not have any such restriction; as long as the element names are the same, they can be anywhere in the form.

As of 1.5.4.1, the code is:

['validate-one-required', 'Please select one of the above options.', function (v,elm) {
var p = elm.parentNode;
var options = p.getElementsByTagName('INPUT');
return $A(options).any(function(elm) {
return $F(elm);
});
}]

I’ve replaced it with the following (Tested in Prototype 1.6.0.2)

['validate-one-required', 'Please select one of the above options.', function (v,elm) {
var options = elm.up('form').descendants().collect( function(s) { if (s.tagName == "INPUT" && s.name == elm.name) return s; }).compact();
return $A(options).any(function(elm) {
return $F(elm);
});
}]

Stepping through that long selector:

1. Get the radio/checkbox input
2. Find the form that contains it
3. Get every non-text element in that form
4. Out of those, find all <input> tags with a matching name
5. Filter out everything that didn’t match (which shows up as undefined)

The message will still show up after the item with the class ‘validate-one-required’, which should probably be the last one. However, now your radio/checkbox inputs can be in whatever markup structure you want.

-Sud.

Posted in JavaScript |

One Response to “Updating ‘validate-one-required’ in Prototype.js Dexagogo validation”

1. dragonfly Says:
   July 1st, 2008 at 4:06 am

   Thanks for the bugfix, now it’s working!!