Is there a way to have a pop up with a yes/no comes when a player clicks submit on a form? If user clicks yes then it executes the form post, if user clicks no then it cancels it, how would I achieve this with silverstripe forms?

Or even better, is there a way I can tell it to execute a custom java script function prior to submitting the form? Then if result returns true submit, else do nothing.

Hi Bagzli,

If you are talking about doing this on the front-end of a website, you can include any javascript you want wherever your form is rendered by using the Requirements class. http://doc.silverstripe.org/en/developer_guides/templates/requirements The fact that the form is generated by SilverStripe doesn't matter, you can use the same kind of javascript you would for any HTML form.

If you're talking about doing it in the CMS you can include extra javascript the same way - add a javascript Requirements call in your getCMSFields() function then follow this guide to see how to use jQuery Entwine to bind your validation behaviour to your form: http://doc.silverstripe.org/en/developer_guides/customising_the_admin_interface/javascript_development

In order to do that, I need to have something like this

<form onsubmit="return confirm('Do you really want to submit the form?');">

the problem is that the form tag is auto generated, so how do I inject my javascript to tell it to call a function prior to submitting?

Rather than inlining your javascript on the form, consider attaching the behaviour by targeting the element you want in separate script. This is easy to do with jQuery or you can do it with native javascript doing something like:

var form = document.getElementById('MyForm'); // ID of the form you want to target - SilverStripe will automatically generate an ID on the form
form.onsubmit = function() {
    //Do stuff here
};

Note that you would have to fire this script after the form is loaded in to the DOM, either by placing it in a script tag after the form, or firing the code in a window.onload or similar.

If you want to use jQuery see http://api.jquery.com/submit/ and http://api.jquery.com/ready/