Client side message boxes

Depend on this module and return

{
    'type': 'ir.actions.act_window.message',
    'title': _('My title'),
    'message': _('My message'),
    # optional title of the close button, if not set, will be _('Close')
    # if set False, no close button will be shown
    'close_button_title': 'Make this window go away',
    # Use HTML instead of text
    'is_html_message': True,
    # this is an optional list of buttons to show
    'buttons': [
        # a button can be any action (also ir.actions.report.xml et al)
        {
            'type': 'ir.actions.act_window',
            'name': 'All customers',
            'res_model': 'res.partner',
            'view_mode': 'form',
            'views': [[False, 'list'], [False, 'form']],
            'domain': [('customer', '=', True)],
        },
        # or if type == method, you need to pass a model, a method name and
        # parameters
        {
            'type': 'method',
            'name': _('Yes, do it'),
            'model': self._name,
            'method': 'myfunction',
            # list of arguments to pass positionally
            'args': [self.ids],
            # dictionary of keyword arguments
            'kwargs': {'force': True},
            # button style
            'classes': 'btn-primary',
        }
    ]
}

You are responsible for translating the messages.

Demo data contains server actions on the module model that demo the features of this addon, those are also convenient for reviewers and migrators to verify correct function.