In simple_form, can't submit boolean as radio_button if the field is disabled

Question

I am using simple_form 2.0. I have a Boolean field 'stock' which I am trying to submit as radio buttons.

<%= f.input :stock , :as => :radio_buttons, :collection => [['Purchase Indent', false],
['Stock', true]], label:"Shipments From" , :disabled => true%>

The stock is marked as false before rendering the form.

Once I submit the form the stock itself is missing from the parameter and I get this error.

Because I am validating stock's inclusion.

validates_inclusion_of :stock, :in => [true, false]

It works fine if i don't disable the field. But I don't want user to be able to change it. Please help.

Update

The reason is that, the disabled fields are never sent.
http://www.w3.org/TR/html401/interact/forms.html#h-17.12

Seems like making it read-only will help.
https://github.com/plataformatec/simple_form/pull/367

But, the news is radio buttons can't be made read only.
Why can't radio buttons be "readonly"?

Answer 1

One option is to separate the buttons and only disable the unselected option:

<%= f.input :stock , :as => :radio_buttons, collection: [['Purchase Indent', false]], label:"Shipments From" %>
<%= f.input :stock , :as => :radio_buttons, collection: [['Stock', true]], label:"" , :disabled => true %>

Another option would be to add a hidden input with the desired value.

Answer 2

Remember not to trust user submitted data. I don't think you should build it like this, because a hacker can just change the HTML / submit an artificial request even if you disable the form elements. Hidden form elements don't fix this, as anyone with a dom explorer can change the values. Of course, if your model checks and rejects this kind of thing it's not such a big problem.

So to fix the particular problem, just do the visuals as you have already, and re-insert the expected value in your controller's update or create action.

For more info there's lots online e.g. owasp, but I liked the book "How to break web software" from a few years back by some guys at Google.