How should I go about redirecting the user back to my page\'s tab after they authenticate my app? I cannot put one specific url in for the redirect since my app will live on
So when a Page add/install your app, you should store the page's link along with the page's id.
Now when your page tab is loaded, Facebook will send the page parameter which will contain the page id (along with other info, refer to the documentation). You retrieve that id, get the page's link from your db and construct your page tab link, which would be something like (where $page is the page's db record):
$redirect_uri = $page['page_link'] . '?sk=app_' . $APP_ID
Since you are using the PHP-SDK, this is how you construct your login:
$user = $facebook->getUser();
if(!$user) {
$url = $facebook->getLoginUrl(array('redirect_uri' => $redirect_uri, 'scope' => 'read_stream'));
echo "";
exit;
}
Of course you may not want to redirect to the login directly but instead have a call to action link:
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