Safari iOS app does not include any option which can make this possible for users to view source code for a web page. But here is a new Cydia tweak View Source for Safari which is available free under BigBoss repo.
View Source for Safari just works for jailbroken iPad, and does not support iPhone and iPad. Once you have installed View Source for Safari on iPad, a new menu will get added to Safari bar, from where you can access different options like “View Source”, “Details” etc. and user can also take a print out of the source code of a web page via connected Printer.
No doubt View Source for Safari iPad tweak is quite useful for web developers, so just visit BigBoss repo on Cydia and try it out.