@aadami,
For the moment, against my inner self's best judgement, we are going to pull the information together as a single view and display that within the MainContentRegion. Based on the BRD we want to display the information that is already available in other modules but in a single view. Using nested regions would have allowed me to prevent duplicating the code. Unfortunately time constraints prevent me from continuing to work on this. Fortunately we are going to be going through a refactoring effort as part of our next release and the use of nested regions is going to be a part of that effort.
In response to your answer, and for the benefit of others, the only issue I see with your approach is in publishing the event from the parent regionsOnNavigatedFrom. Based on my understanding of INavigationAware we would not be able to stop the parent view from navigating once inside theOnNavigatedFrom method. Given that the SaveView is being used to provide the opportunity to stop the navigation and correct any errors, or continue navigation without saving the changes, we need theSaveView to fire before reaching the OnNavigatedFrom. Since the event would be published from theOnNavigatedFrom method of the parent view we would not be able to stop that navigation if there are errors in the nested views.
I was trying to determine if using scoped regions would provide the "awareness" of the nested regions and cause theirSaveView methods to fire before getting to the OnNavigatedFromof the parent view.
There is possibly some form of workaround for all of this, and I could be wrong (not the first time), but as mentioned above, we have to move forward. When we get into refactoring and work through the nested views issues, I will update the thread.
Thanks Again for taking a look at this.