determine if any of checkbox[] is checked

[Phil Petree]

Happy Easter!

 

I have an array of checkboxes on a form (about 15 of them) arranged in rows like this:

<tr><td><input type='checkbox' name='kitcat[]' ...></td><td>name</td><td>description</td></tr>

 

What I have been trying to use is this:

$("input:checkbox[name=kitcat]:checked").each(function() {

    // if one is checked, we validated

    return true;

});

 

What I'm getting is an error saying: Unable to get value of the property 'each': object is null or undefined

 

What's the trick to this?

[Jason Westbrook]

Try adding a separate class to all of your checkboxes that are in the group and then do this

if( $$('.groupchecks:checked').length == 0 )

{

    //no checked checkboxes

{

Jason Westbrook | T: 313-799-3770 | jwest...@gmail.com

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[mike]

try
$$("...")
because $() equal document.getElementById

[Phil Petree]

Hey Jason... I guess the rest of the group are all slugs! How dare they take Easer off! LOL

 

I had kinda come to the same conclusion... what I implemented was:

      if($$('input:checked').length > 0)
        return true;

This kind of works because the ONLY input on this page are checkboxes (think of a wizard) but I was really looking to pass names (kitcat[]) in so that it could be more flexible and accomodate future mods.

 

In your method, I need to mod all 17 checkboxes to include the same class name which is currently: "validate-onein-group"

 

Is there a way to collect all checkboxes with the same name?

[Jason Westbrook]

typically when I build forms like that I have a database that is giving me all the data so I only have to update the loop once for all the checkboxes :-)

but yes you can use the $$() Selector method to use the names - I think you have to do it this way though

$$("input[name='kitcat[]']:checked")    //but I'm not sure how Sizzle will handle the bracket in the name

or

$("input[name^='kitcat']:checked")     //this is probably more safe but it will match more elements as it gets all elements that have a name attribute that starts with "kitcat" (starts with is ^= instead of =)

Jason Westbrook | T: 313-799-3770 | jwest...@gmail.com

[Phil Petree]

// this works with names that contain spaces and arrays[]...

 

Validation.add('validate-one-array', 'Error message text', function(value, element) {
    var elmName = "input:checkbox[name='" +element.name +"']";
    var bChecked = false;  // not validated
    $$(elmName).each(function(elm) {
       if( $(elm).checked )
         bChecked = true;     // if one is checked, we validated
    });
    return bChecked;
  });

[Jason Westbrook]

Prototype has a method for what you are trying called any()

http://api.prototypejs.org/language/Enumerable/prototype/any/

you create an iterator function and pass it to any

    var elmName = "input:checkbox[name='" +element.name +"']";
    var bChecked = false;  // not validated

    var anychecked = $$(elmName).any(function(n) {

         return n.checked;

    });

    anychecked will be true or false

Jason Westbrook | T: 313-799-3770 | jwest...@gmail.com

[Phil Petree]

Ha!  I knew there had to be a shorter way to do this!

 

Thanks!