SproutCore Security and Authentication concerns

I've been trying to learn a little about SproutCore, following the "Todos" tutorial, and I have a couple of questions that haven't been able to find online.

1. SproutCore is supposed to move all of the business logic to the client. How is that not insecure? A malicious user could easily tamper with the code (since it's all on the client) and change the way the app behaves. How am I wrong here?
2. SproutCore uses "DataStores", and some of them can be remote. How can I avoid that a malicious user does not interact with the backend on h开发者_如何学JAVAis own? Using some sort of API key wouldn't work since the code is on the client side. Is there some sort of convention here? Any ideas? This really bugs me.

Thanks in advance!

PS: Anyone thinks Cappuccino is a better alternative? I decided to go with SproutCore because the documentation on Cappuccino seemed pretty bad, although SproutCore's doesn't get any better.

Ian

your concerns are valid. The thing is, they apply to all client side code, no matter what framework. So:

Web applications are complicated things. Moving processing to the client is a good thing, because it speeds up the responsiveness of the application. However, it is imperative that the server validate all data inputs, just like in any other web application.

Additionally, all web applications should use the well known authentication/authorization paradigms that are prevalent in system security. Authentication means you must verify that the user is who they say they are, and they can use the system, with Authorization means that the server must verify that the user can do what they are trying e.g. can they create a new data entry, or edit an existing one. It is good design to not present users with UI options that they are not allowed to perform, but you should not rely on that.

All web applications must do those things.

With respect to the 'interacting with the back end' concern: Again, all web applications have this concern. You can open up firebug/webkit, and look at all the the xhr requests that RIAs use in their operations, and mimic them to try to do something on that system. Again, this concern is dealt with by the authentication/authorization checks that you must implement. Anybody can use any webclient to send a request to the server. It is up to the developer to validate that request.

The DataSources in SproutCore are just an abstraction around how SC apps interact with the server. At the end of the day, however, all SC is doing is making XHR requests to the server, like any other RIA.