koala and facebook how to get page id

I'm new on Facebook API and I'm experimenting them with Koala gem. I'm facing those situation right now:

• I have a canvas app, there is a way t开发者_运维百科o retrieve the page id where the app has ben installed?
• On my canvas app can I fire an event when a user install the app? I'd like to know when someone install it and save page id and user id in my database.

Any hints are welcome. Thanks

Use this to install: https://www.facebook.com/dialog/pagetab?app_id=YOUR_APP_ID&display=popup&next=YOUR_URL

At YOUR_URL,you can get the facebook parameter tabs_added. Save it to database.