Show error within JSF page and continue rendering it instead of redirecting to separate error page

Whenever there is an error during the load of a JSF facelet, JSF stops rendering the page at the point of the error and shows the error page instead (default behavior). I want JSF to continue rendering a page instead and show the exception/error within the page. For example if the page is loading a "portlet", which throws an exception, that exception would be shown as text within the portlet. I don't want the whole page to be forwarded to a separate error page.

I have initialized my own ExceptionHandlerFactory and ExceptionHandler implementations and I can iterate over the ExceptionQueueEvents succesfully. However, I don't know how to instruct JSF to continue loading the page despite of the error. Is this even the right approach at all? Is the ExceptionHandler called after (as I suppose) or in the middle processing the facelet? If after, is there anything I can do within my ExceptionHandler?

I know I should:

Hide the parts that user cannot access (my specific case relates to security, when user tries to load content he does not have rights to. However, I am looking for a global answer to this)
Manually handle the errors so unexpected exceptions would not be thrown

However, I want the user to be able to continue using the system despite of some minor component failure (for example if some newsfeed portlet throws an error that shouldn't prevent the user from seeing other content and using it).

I am using Mojarra 2.0.2. I feel this is a very simple to solve but I cannot figure it out :(

Solution

Doing so would mean that you're giving the enduser a halfbaked HTML page (because JSF hasn't (and can't) complete the HTML rendering) and it's unspecified how the webbrowser would display the page.

Don't do it.