如果注册，请登录用户（Firebase Facebook / google auth）

Question

i´m want to check if the user who want to sign in using the facebook or google auth in to my web app is register on the real time database of firebase, so the idea is after the user press the button of sign in with facebook/google, first check in to the real time database if the uid is already on the real time database before redirect the user to another URL, for this i´m using the next function:

  app.auth = function(){
    firebase.auth().onAuthStateChanged(function(user) {
      if (user) {
        var users_ref = firebase.database().ref('dream_wedding_users');
        var register_user;
        var register = false;
        users_ref.on('value', function(snapshot) {
          register_user = snapshot.val();
        });
        $.each(register_user, function(index, val){
          if(user.uid === index){
            register = true;
          }
        })
        if(!register){
          firebase.auth().signOut();
          $('#login').modal('hide');
          $('#modal_register').modal('show');
          return false;
        }else{
          $(window).attr('location', 'http://localhost/wedding/en/gallery_en.php');
        }
      }
    });
  }

and for the auth function just the regular auth function for facebook and google that attach to a button.

  app.facebook_login = function(){
    var provider = new firebase.auth.FacebookAuthProvider();
    firebase.auth().signInWithPopup(provider).then(function(result) {
      // This gives you a Facebook Access Token. You can use it to access the Facebook API.
      var token = result.credential.accessToken;
      // The signed-in user info.
      var user = result.user;
      // ...
    }).catch(function(error) {
      console.log(error)
    });
  }

  app.google_login = function(){
    var provider = new firebase.auth.GoogleAuthProvider();
    firebase.auth().signInWithPopup(provider).then(function(result) {
      // This gives you a Google Access Token. You can use it to access the Google API.
      var token = result.credential.accessToken;
      // The signed-in user info.
      var user = result.user;
      // ...
      firebase.auth().signInWithRedirect(provider);
    }).catch(function(error) {
      console.log(error);
    });
  }

my problem is the next one, when i click sign in facebook or google, first login the user, then redirect the user, then check is the user is register on the real time data base and then logout the user if is not register and then show the modal. i don´t want that redirect the user i want that check if the user is register and then show the modal of "register" if the user is not register without redirect, and redirect if the user is register.

Answer 1

You want to add a unique user , if it is already not registered right ? here is the valid way:

var usernew = result.additionalUserInfo.isNewUser
console.log('Is this a new user ? => ' + usernew );

complete code is as follows:

var provider = new firebase.auth.GoogleAuthProvider();
firebase.auth().signInWithPopup(provider).then(function(result){
    var usernew = result.additionalUserInfo.isNewUser;
    console.log('Is this a new user ? => ' + usernew );
    if (usernew == true) {
        NewUser();
    }
    var token = result.credential.accessToken;       
    user = result.user; 
    //  alert(JSON.stringify(user.photoURL))                                                      
}).catch(function(error) {
    var errorCode = error.code;
    var errorMessage = error.message;
    var email = error.email;
    var credential = error.credential;
});

add user if it is not registered:

function NewUser(){
    firebase.database().ref('/users').push({
        Name : 'Johnson'
        Age : '22'
    })
}