How to display a dialog with warning message from controller in Odoo?

Question

Is it possible to display a warning message when overriding a controller function? This is the code I have:

raise Warning(_('Entered Quantity is greater than quantity on source.'))
return super(CheckCart, self).cart(**post)

I want to render the cart template but also raise a Warning, but I get the following:

500: Internal Server Error Error Error message: ('Entered Quantity is greater than quantity on source.', '')

Traceback

Without anything else.

Answer 1

Controller File.

request.render("custom_module_name.redirect_fail_page", {})

XML File.

<template id="redirect_fail_page" name="Failure Code Page">
    <div>
          <span>Failed</span>
    </div>
    <script>
        setTimeout(function(){
            window.location.href = '/';
        }, 1100)
    </script>
</template>

Here you can use request.render