Register with Facebook sometimes doesn't provi

Question

I'm using Register with Facebook as one of the ways to log in to my web app, and expressly ask for the "email" permission..

On login, some of the user data ($facebook->api('/me')) is stored into the users database, however, sometimes the email field just doesn't exist - is this a common problem?

Answer 1

Try:

// Just to make sure email are permitted
//$facebook->getLoginUrl(array('req_perms' => 'email'))

// Request email
FB.api('/me?scope=email', function(response) { /*...*/ });

Or:

$email = $facebook->api('user_id?fields=email');

PROBLEMS:

• The user changed the visibility of its email address to "only me" and thus you have no way to get it.
• The user registered with SMS instead of email as mentioned in the previous answer.

ALTERNATIVE:

If you absolutely need to contact the user but you cannot get its email address nyou can still get its Facebook email (everybody has this email): "[e-mail]".

If the user uses a POP server he will directly receive the email in GMail or others, if not he will receive your email as a private message. The only drawback if this method is that your email must be "plain/text" and not "HTML".

Answer 2

Just a guess...

The facebook documentation says:

note: this field will not be returned if no valid email address is available for the user

Source: https://developers.facebook.com/docs/reference/api/user/

So when an email address become invalid (users who haven't used facebook in years and have destroyed/changed their email address since for example), facebook may stop returning this field.

5% of invalid address may sounds big, but if I check my facebook friends, I think more than 5% of them never use their account, and I wouldn't be surprised if the address they used when they signed in is now invalid.

Answer 3

Users don't always have to provide an email address in order to use Facebook. They can also sign up via SMS, though it's far less common.

In short, FB won't always have an email address, so can't serve it to your app.

Answer 4

One thing is Users don't always have to provide an email address in order to use Facebook(could have registered through mobile)- as mentioned by Colm. Apart from this-

Please check that if the user has definitely granted you the email extended permission or it hasn't subsequently been revoked. To have a check on this you could use the permissions api-

/USER/permissions

Answer 5

In addition to what @Jigar Jain wrote above, users can actually uncheck the email permission during the sign inflow. If that's the case, his/her email address will not be returned by Facebook.

It's up to you to implement a logic that makes login unsuccessful if user unchecks the email permission, to force your users to choose another login method that will guarantee that a return of user's email address.

Answer 6

I had similar problem & I found the cause for this. This problem occurs for users who have not set their Primary Email Address (They have many email address but they haven’t pointed out which is their primary email address) under General Account setting tab.

I tried using such accounts on various famous sites which has Facebook login & even they couldn’t retrieve the email address from such accounts.

So, its not the problem with the code(Assuming u have asked for permissions). We just have to handle such scenarios & let users know that we didn’t receive their email address. Like Klout does.

Thanks