To disable a send button if fields empty by jQuery

Question

How can you disable the send -button if there is one or more input -fields empty?

My attempt in pseudo-code

if ( $("input:empty") ) {
    $("input:disabled") 
}
else 
  // enable the ask_question -button

I have been reading these articles without finding a right solution

1. Official docs about empty: this is like not relevant because it looks for all input -fields
2. a thread about disabled -feature in jQuery: this seems to be relevant
3. to be able to test jQuery Firefox/terminal: to get a testing environment would help me most

I use at the moment the following code. It contains one bug about the character ;, but I cannot find it.

#1

$(document).ready(function(){
    $("#ask_form").validate(){
        rules: {
            username {
                required: true,
                minlenghth: 2
            },
            email: {
                required: true;
                minlength: 6
            },
            password {
                required: true,                                                                                                                                    
                minlength: 6
            }
        } 
    });
}

#2 Meder's code

I slighhtly modified Meder's code. It disables the send -button permanently so it has a bug too.

$(document).ready(function(){
    var inputs = $('input', '#ask_form'), empty = false;
    // can also use :input but it will grab textarea/select elements and you need to check for those..

    inputs.each(function() {
        if ( $(this).val() == '' ) {
            empty = true;
            return;
        }
    });

    if ( empty ) {
        $('.ask_question').attr('disabled', 'disabled'); // or true I believe.
    }
});

Stacystadholder

Answer 1

var $submit = $("input[type=submit]");
if ( $("input:empty").length > 0 ) {
   $submit.attr("disabled","disabled");
} else {
   $submit.removeAttr("disabled");
}

Graniah

Just make sure to put this in an onChange event or similar so it will fire each time a field is changed. – Lula

Your code does disable the buttons. However, it does disable buttons too when the fields are not empty. - How do you read this input:empty).length > 0 in English? - My attempt to apply the given rule to the tag input which is empty such that its length is greater than zero. - This does not make sense to me, since my consideration leads to a contradiction. – Klystron

I removed .length > 0, but the buttons remain disabled. – Klystron

what this does is gets a collection of all the input elements that have no children, including text nodes. the length property just determines how many items are in the collection. if there are 0 items in the collection, the length will be 0. you can obviously be more specific in your selector, like $("input.myInputs:empty") but this should do the trick. – Graniah

i updated my code so that if everything is ok but previously was not, the button becomes enabled again – Graniah

Your code is still buggy: it does not disable any button this time. Why did you changed $("input[type=submit]").attr("disabled","disabled"); to ` $submit.attr("disabled","disabled");`? - I run your code also with a modification of your last code to your old code, but the same problem persists. – Klystron

look, masi, it's not going to work verbatim. i'm giving you the framework to build upon. you have to insert the selectors that are relevant to your system. i pulled out var $submit = $("input[type=submit]"); so that I didn't have to repeat myself and also so that the collection is called only once, which will speed up the process. – Graniah

if you want to go back and put in $("input[type=submit]"); in place of $submit it will work the same. go for it. – Graniah

Answer 2

jQuery validation plugin
Documentation
Demo

Meninges

Thank you for the links! I am using the code in the demo at the moment. There is one bug in my code of the question. – Klystron

Answer 3

var inputs = $('input', 'form#foo'), empty = false;
// can also use :input but it will grab textarea/select elements and you need to check for those..

inputs.each(function() {
    if ( $(this).val() == '' ) {
        empty = true;
        return;
    }
});

if ( empty ) {
    $('#el').attr('disabled', 'disabled'); // or true I believe.
}

Labroid

Your code has the same problem as Jason's. It disables the send -button permanently. – Klystron

Answer 4

Missing the closing, try this for example #1:

$(document).ready(function(){
    $("#ask_form").validate(){
        rules: {
            username {
                required: true,
                minlenghth: 2
            },
            email: {
                required: true;
                minlength: 6
            },
            password {
                required: true,                                                                                                                                    
                minlength: 6
            }
        } 
    });
});

Meninges