We are working on importing data on regular interval from external system into CMS (ver: 10.8). Once pages are created into CMS from external data, we want to give Editor an option for explicitly updating data for a single page. Can we provide a button on a page in EditMode so that Editor can fetch data for that page? Is this doable and if yes, what event we will fire at backend so that we can get data from external system again.
This would be absolutely possible, however I'll leave a developer to give you the actual APIs you'll be hitting...
I just wanted to bring ContentProviders to your attention. Could be interesting to have a look at in context of your question.