I solved it with the Facebook SDK javascript adding:
(function (d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) {
return;
}
js = d.createElement(s);
js.id = id;
js.src = "https://connect.facebook.net/en_US/sdk.js";
fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));
window.fbAsyncInit = function () {
FB.init({
appId: 'myAppID',
status: true,
cookie: true,
oauth: true,
xfbml: true,
version: 'v2.7'
});
}
Then in the action of my logout button:
FB.getLoginStatus(function(response) {
if ((response.status)&&(response.status=='connected')) {
FB.logout(function(response) {
//manage: user is logout
console.log(response);
});
} else {
//manage: user is not connected.
}
});
The 3 disconnection scenarios mentioned in the documentation are important: https://developers.facebook.com/docs/reference/javascript/FB.logout/