Facebook 图形应用程序接口，如何获得用户的电子邮件？

https://graph.facebook.com/me

will give you info about the currently logged-in user, but you'll need to supply an oauth token. See:

http://developers.facebook.com/docs/reference/api/user

The only way to get the users e-mail address is to request extended permissions on the email field. The user must allow you to see this and you cannot get the e-mail addresses of the user's friends.

http://developers.facebook.com/docs/authentication/permissions

You can do this if you are using Facebook connect by passing scope=email in the get string of your call to the Auth Dialog.

I'd recommend using an SDK instead of file_get_contents as it makes it far easier to perform the Oauth authentication.

To get the user email, you have to log in the user with his Facebook account using the email permission. Use for that the Facebook PHP SDK (see on github) as following.

First check if the user is already logged in :

require "facebook.php";
$facebook = new Facebook(array(
'appId'  => YOUR_APP_ID,
'secret' => YOUR_APP_SECRET,
));


$user = $facebook->getUser();
if ($user) {
try {
$user_profile = $facebook->api('/me');
} catch (FacebookApiException $e) {
$user = null;
}
}

If he his not, you can display the login link asking for the email permission :

if (!$user) {
$args = array('scope' => 'email');
echo '<a href="' . $facebook->getLoginUrl() . '">Login with Facebook</a>';
} else {
echo '<a href="' . $facebook->getLogoutUrl() . '">Logout</a>';
}

When he is logged in the email can be found in the $user_profile array.

Hope that helps !

Open base_facebook.php Add Access_token at function getLoginUrl()

array_merge(array(
'access_token' => $this->getAccessToken(),
'client_id' => $this->getAppId(),
'redirect_uri' => $currentUrl, // possibly overwritten
'state' => $this->state),
$params);

and Use scope for Email Permission

if ($user) {
echo $logoutUrl = $facebook->getLogoutUrl();
} else {
echo $loginUrl = $facebook->getLoginUrl(array('scope' => 'email,read_stream'));
}

You can retrieve the email address from the logged in user's profile. Here is the code snippet

<?php


$facebook = new Facebook(array(
'appId'  => $initMe["appId"],
'secret' => $initMe["appSecret"],
));


$facebook->setAccessToken($initMe["accessToken"]);
$user = $facebook->getUser();


if ($user) {
$user_profile = $facebook->api('/me');
print_r($user_profile["email"]);
}
?>

The email in the profile can be obtained using extended permission but I Guess it's not possible to get the email used to login fb. In my app i wanted to display mulitple fb accounts of a user in a list, i wanted to show the login emails of fb accounts as a unique identifier of the respective accounts but i couldn't get it off from fb, all i got was the primary email in the user profile but in my case my login email and my primary email are different.

// Facebook SDK v5 for PHP
// https://developers.facebook.com/docs/php/gettingstarted/5.0.0


$fb = new Facebook\Facebook([
'app_id' => '{app-id}',
'app_secret' => '{app-secret}',
'default_graph_version' => 'v2.4',
]);


$fb->setDefaultAccessToken($_SESSION['facebook_access_token']);
$response = $fb->get('/me?locale=en_US&fields=name,email');
$userNode = $response->getGraphUser();
var_dump(
$userNode->getField('email'), $userNode['email']
);

Make sure your Facebook application is published. In order to receive data for email, public_profile and user_friends your app must be made available to public.

You can disable it later for development purposes and still get email field.

The following tools can be useful during development:

Access Token Debugger: Paste in an access token for details

https://developers.facebook.com/tools/debug/accesstoken/

Graph API Explorer: Test requests to the graph api after pasting in your access token

https://developers.facebook.com/tools/explorer

Make sure to fully specify the version number of the API as something like "v2.11" and not "2.11"

I'm not sure what it defaults to if this is incorrect, but I got some odd errors trying to just retrieve the email when I missed the v.

Just add these code block on status return, and start passing a query string object {}. For JavaScript devs

After initializing your sdk.

step 1: // get login status

$(document).ready(function($) {
FB.getLoginStatus(function(response) {
statusChangeCallback(response);
console.log(response);
});
});

This will check on document load and get your login status check if users has been logged in.

Then the function checkLoginState is called, and response is pass to statusChangeCallback

function checkLoginState() {
FB.getLoginStatus(function(response) {
statusChangeCallback(response);
});
}

Step 2: Let you get the response data from the status

function statusChangeCallback(response) {
// body...
if(response.status === 'connected'){
// setElements(true);
let userId = response.authResponse.userID;
// console.log(userId);
console.log('login');
getUserInfo(userId);


}else{
// setElements(false);
console.log('not logged in !');
}
}

This also has the userid which is being set to variable, then a getUserInfo func is called to fetch user information using the Graph-api.

function getUserInfo(userId) {
// body...
FB.api(
'/'+userId+'/?fields=id,name,email',
'GET',
{},
function(response) {
// Insert your code here
// console.log(response);
let email = response.email;
loginViaEmail(email);
}
);
}

After passing the userid as an argument, the function then fetch all information relating to that userid. Note: in my case i was looking for the email, as to allowed me run a function that can logged user via email only.

// login via email

function loginViaEmail(email) {
// body...
let token = '\{\{ csrf_token() }}';


let data = {
_token:token,
email:email
}


$.ajax({
url: '/login/via/email',
type: 'POST',
dataType: 'json',
data: data,
success: function(data){
console.log(data);
if(data.status == 'success'){
window.location.href = '/dashboard';
}


if(data.status == 'info'){
window.location.href = '/create-account';
}
},
error: function(data){
console.log('Error logging in via email !');
// alert('Fail to send login request !');
}
});
}

Assuming you've requested email permissions when the user logged in from your app and you have a valid token,

With the fetch api you can just

const token = "some_valid_token";
const response = await fetch(
`https://graph.facebook.com/me?fields=email&access_token=${token}`
);
const result = await response.json();

result will be:

{
"id": "some_id",
"email": "name@example.org"
}

id will be returned anyway.

You can add to the fields query param more stuff, but you need permissions for them if they are not on the public profile (name is public).

?fields=name,email,user_birthday&token=

https://developers.facebook.com/docs/facebook-login/permissions

For me the problem with collecting user's email addres on PHP side (getGraphUser() method) was, that the default behavior of facebook-rendered button (on WEBSIDE side, created with xfbml=1) is to implicity calling FB.login() with the scope NOT including "email".

That means you MUST:

1) call

FB.login(....,{scope: email})

manifestly, creating your own button to start login process

OR

2) add scope="email" attribute to the xfbml button

<div class="fb-login-button" data-size="large" data-button-type="continue_with" data-
layout="rounded" data-auto-logout-link="false" data-use-continue-as="true" data-
width="1000px" scope="email"></div>

to be able to collect email address on PHP side.

Hope it helps.

First, activate your application at the Facebook Developer center. Applications in development mode are not allowed to retrieve the e-mail field.

If the user is not logged in, you need to login and specify that your application/site will need the e-mail field.

FB.login(
function(response) {
console.log('Welcome!');
},
{scope: 'email'}
);

Then, after the login, or if the user is already logged, retrieve the e-mail using the Facebook API, specifying the field email:

FB.api('/me', {fields: 'name,email'}, (response) => {
console.log(response.name + ', ' + response.email);
console.log('full response: ', response);
});