Quote:
...does opus have a function to save a page state, so that when a page is changed within a presentation the original page remains the same.
Let me ask you to clarify your question.
Are you saying that you want:
A. to go back and view the Page in it's original state? (you said "...the original page remains the same." )
B. to have the User interact with the Page, make some changes, leave the Page and then come back to previous page... not in it's original fresh state but in the way the User left it (with his changes)? (you said "...save a page state")
For "A", that is the default mode for Opus ( a Page will appear in its INITIAL state )
For "B", it is as Mack replied... , do some scripting to save & later reload from saved data/state info.
There is a bit of a special case. But not used so much for 'normal' navigating from page to page to page. And that is this: If you want to depart from normal navigation through content and go to another Page knowing that you will come back to the page you just left, you can use Opus VIEWS. For example, say the User is navigating through content and making changes/interacting, but he wants to go to a 'help page' or a 'preferences/options page' -- you simply create a separate Chapter (holding the 'help page') and set the Chapter Properties to "Display in Window". When User goes to the 'help page', it will open in a new Window in front of the normal content page. (use standard Actions under category of 'Window' to close that 'help page' -- Opus calls this a 'View'). Once the 'help page' is Closed, the regular content Page is just where you left it, including User interactions/changes.
Hope that helps.