If I have a prevalidate plugin which, amongst other things, will ensure that a newly created object is valid how can I get feedback from that plugin to the user if it isn't valid?
So for example if I have "widget" entity and whether users can create widgets depends on some function in the plugin can I get a message back from the plugin to say, for example, insufficient "sprockets in stock to create widgets" or"Sprockets can not be created in requested date range". These are errors which are trivial to handle in a plugin but would be a real pain in the proverbials to handle in Javascript. Now in a web development environment I'd do that through a simple AJAX callback but how do I do that in CRM?