When displaying web content within an iPhone App, we can generally choose between displaying that content within a UIWebView, or popping open an instance of Safari.
I’ve generally found that for related content, the experience of displaying the content “in-app” by using a UIWebView is cleaner (maybe in a modal view or navigationcontroller), though it’s a bit more work to do so.
For possibly unrelated content, I’ll generally go for Safari.
Is there any established line of reasoning for picking one method over the other?
EDIT: Along with the technical, what’s your reasoning with respect to user experience?
With respect to the UX, I think it depends on when the web content is displayed to the user in the user’s workflow. Also, how frequently it is done & how distracting it can be? These things matter because you want to keep the user inside your app for the maximum amount of time (there is a good chance that the user won’t come back). It is frustrating for the user if she has to leave your app to go to Safari multiple times & return back to your application within a short span of time. Moreover, if by any chance you have specified that your app be terminated if it is sent to the background, then you should not be launching Safari.
For example, the same factors hold when you create you Settings page. To quote from the HIG,
HTH,
Akshay