74
votes

I'm doing some simple form validation here and got stuck on a very basic issue. I have 5 field pairs for name and entree (for a dinner registration). The user can enter 1-5 pairs, but an entree must be selected if a name is present. Code:

http://jsfiddle.net/eecTN/1/

<form>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    <input type="submit" value="Submit">
</form>
// Prevent form submit if any entrees are missing
$('form').submit(function(e){

    e.preventDefault();

    // Cycle through each Attendee Name
    $('[name="atendeename[]"]', this).each(function(index, el){

        // If there is a value
        if ($(el).val()) {

            // Find adjacent entree input
            var entree = $(el).next('input');

            // If entree is empty, don't submit form
            if ( ! entree.val()) {
                alert('Please select an entree');
                entree.focus();
                return false;
            }
        }
    });

    $('form').unbind('submit').submit();

});

The error message is working, but it's submitting the form every time. I know there's something wrong with this line:

$('form').unbind('submit').submit();

...but I'm not sure what I need to do.

11
Why you make unbind for your submit form ??? - d.danailov
I've seen this post but the solutions look dubious and use setTimeout: stackoverflow.com/questions/14866626/… - Wesley Murch
@d.danailov So it doesn't run the validation again. Please, help me out - what do I need to do? - Wesley Murch
Why don't you change it so that e.preventDefault() is only called if validation fails? Then you can remove the line with .unbind().submit(). - nnnnnn
Ok other one is OK but also idea here jsfiddle.net/eecTN/9 thank you for patience - stormdrain

11 Answers

98
votes

The simplest solution is just to not call e.preventDefault() unless validation actually fails. Move that line inside the inner if statement, and remove the last line of the function with the .unbind().submit().

44
votes

Use the native element.submit() to circumvent the preventDefault in the jQuery handler, and note that your return statement only returns from the each loop, it does not return from the event handler

$('form').submit(function(e){
    e.preventDefault();

    var valid = true;

    $('[name="atendeename[]"]', this).each(function(index, el){

        if ( $(el).val() ) {
            var entree = $(el).next('input');

            if ( ! entree.val()) {
                entree.focus();
                valid = false;
            }
        }
    });

    if (valid) this.submit();

});
29
votes

Actually this seems to be the correct way:

$('form').submit(function(e){

    //prevent default
    e.preventDefault();

    //do something here

    //continue submitting
    e.currentTarget.submit();

});
15
votes

The problem is that, even if you see the error, your return false affects the callback of the .each() method ... so, even if there is an error, you reach the line

$('form').unbind('submit').submit();

and the form is submitted.

You should create a variable, validated, for example, and set it to true. Then, in the callback, instead of return false, set validated = false.

Finally...

if (validated) $('form').unbind('submit').submit();

This way, only if there are no errors will the form be submitted.

6
votes
$('form').submit(function(e){

    var submitAllow = true;

    // Cycle through each Attendee Name
    $('[name="atendeename[]"]', this).each(function(index, el){

        // If there is a value
        if ($(el).val()) {

            // Find adjacent entree input
            var entree = $(el).next('input');

            // If entree is empty, don't submit form
            if ( ! entree.val()) {
                alert('Please select an entree');
                entree.focus();
                submitAllow = false;
                return false;
            }
        }
    });

    return submitAllow;

});
2
votes

Sorry for delay, but I will try to make perfect form :)

I will added Count validation steps and check every time not .val(). Check .length, because I think is better pattern in your case. Of course remove unbind function.

My jsFiddle

Of course source code:

// Prevent form submit if any entrees are missing
$('form').submit(function(e){

    e.preventDefault();

    var formIsValid = true;

    // Count validation steps
    var validationLoop = 0;

    // Cycle through each Attendee Name
    $('[name="atendeename[]"]', this).each(function(index, el){

        // If there is a value
        if ($(el).val().length > 0) {
            validationLoop++;

            // Find adjacent entree input
            var entree = $(el).next('input');

            var entreeValue = entree.val();

            // If entree is empty, don't submit form
            if (entreeValue.length === 0) {
                alert('Please select an entree');
                entree.focus();
                formIsValid = false;
                return false;
            }

        }

    });

    if (formIsValid && validationLoop > 0) {
        alert("Correct Form");
        return true;
    } else {
        return false;
    }

});
1
votes

came across the same prob and found no straight solution to it on the forums etc. Finally the following solution worked perfectly for me: simply implement the following logic inside your event handler function for the form 'submit' Event:

document.getElementById('myForm').addEventListener('submit', handlerToTheSubmitEvent);

function handlerToTheSubmitEvent(e){
    //DO NOT use e.preventDefault();
   
    /*
    your form validation logic goes here
    */

    if(allInputsValidatedSuccessfully()){
         return true;
     }
     else{
         return false; 
     }
}

SIMPLE AS THAT; NOTE: when a 'false' is returned from the handler of the form 'submit' event, the form is not submitted to the URI specified in the action attribute of your html markup; until and unless a 'true' is returned by the handler; and as soon as all your input fields are validated a 'true' will be returned by the Event handler, and your form is gonna be submitted;

ALSO NOTE THAT: the function call inside the if() condition is basically your own implementation of ensuring that all the fields are validated and consequently a 'true' must be returned from there otherwise 'false'

1
votes
$(document).ready(function(){
      $('#myform').on('submit',function(event){
            // block form submit event
            event.preventDefault();

            // Do some stuff here
            ...

            // Continue the form submit
            event.currentTarget.submit();
      });
});

Source

0
votes

In my case there was a race, as I needed the ajax response to fill a hidden field and send the form after it's filled. I fixed it with putting e.preventDefault() into a condition.

var all_is_done=false;
$("form").submit(function(e){
  if(all_is_done==false){
   e.preventDefault();
   do_the_stuff();
  }
});
function do_the_stuf(){
  //do stuff
  all_is_done=true;
  $("form").submit();
}
-1
votes

Why not bind the submit button event than the form itself? it would really much easier and safer if you bind the buttons than the form itself as the form will mostly submit unless you will use preventDefault()

$("#btn-submit").on("click", function (e) {
    var submitAllow = true;
    $('[name="atendeename[]"]', this).each(function(index, el){
        // If there is a value
        if ($(el).val()) {
            // Find adjacent entree input
            var entree = $(el).next('input');

            // If entree is empty, don't submit form
            if ( ! entree.val()) {
                alert('Please select an entree');
                entree.focus();
                submitAllow = false;
                return false;
            }
        }
    });
    if (submitAllow) {
        $("#form-attendee").submit();
    }
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id="form-attendee">
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    Name: <input name="atendeename[]">
    Entree: <input name="entree[]"><br>
    <button type="button" id="btn-submit">Submit<button>
</form>
-1
votes

Binding to the button would not resolve for submissions outside of pressing the button e.g. pressing enter