The unicity of email should be checked before inserting the user record in Parse using the Facebook email

[prempena]

The user email must be unique in Parse. When a new Facebook user is signing up, the user object is inserted in Parse with an empty email. When trying later to populate the email field using the Facebook API GraphRequest, the updated email may already exists in Parse.

=>The unicity of email should be checked before inserting the user record in Parse using the Facebook email.

[wangmengyan95]

@prempena thanks for opening this issue. I am sorry but I am afraid I do not fully understand your question. By my understanding, the problem is after you populate the email field using the Facebook API GraphRequest, you find the email address has already been used in Parse, so you can not register a ParseUser with this email anymore, is that correct?

[prempena]

Exactly and, moreover, why not refuse immediately the facebook user
creation when the email address (that must be unique in Parse) is
already used ?
Thanks,

Pascal

Le 22/08/2015 00:02, Mengyan Wang a écrit :

@prempena https://github.com/prempena thanks for opening this issue.
I am sorry but I am afraid I do not fully understand your question. By
my understanding, the problem is after you populate the email field
using the Facebook API GraphRequest, you find the email address has
already been used in Parse, so you can not register a ParseUser with
this email anymore, is that correct?

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#49 (comment).

[grantland]

The Facebook user's email is not required to authenticate and not always requested by the developer, so we can't have this functionality in our default implementation, but you may add it to your own implementation.

[prempena]

I understand but if the mail is required and if this email already
exists for another users, it is too late, as the Facebook user record is
already inserted in the Parse database.

Le 22/08/2015 04:01, Grantland Chew a écrit :

The Facebook user's email is not required to authenticate and not
always requested by the developer, so we can't have this functionality
in our default implementation, but you may add it to your own
implementation.

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Reply to this email directly or view it on GitHub
#49 (comment).

[ralphilius]

@grantland Is there anyway we can interfere the callback by ParseUI Login?

[grantland]

Which callback are you referring to?

[ralphilius]

@grantland Facebook Login callback. I want to check existing user before submitting to creation

[grantland]

That is not currently supported

[isramartinez]

Hey @grantland , any update on this? we are starting to build our app and we are relying on Parse-UI for the login/signup but with the auto linking or a callback to implement this by ourselves we may need to stop using parse-ui. I guess there are more people like us that would like to have the option to do that. Thanks!

[ralphilius]

@isramartinez Can we use beforeSave cloud code here? It's just a rough idea since I have not tried it yet.

[isramartinez]

@ralphilius yep I just tried that and actually we can do that. Here is the code sample that is working for me. Is just checking that can contact the FB Graph API and is returning data. We would need to add the logic to check if there is an user with that email already and add the authData to that user.

Parse.Cloud.beforeSave(Parse.User, function(request, response) {
  if(request.object.get("authData")){
    Parse.Cloud.httpRequest({
      url: "https://graph.facebook.com/v2.5/" +
        request.object.get("authData").facebook.id + 
        "?fields=email&access_token=" + 
        request.object.get("authData").facebook.access_token,
      success:function(httpResponse){
        console.log(httpResponse.data.email);
        return response.success();
      },
      error: function(error){
        return response.error();
      }});
  }else{
    response.success();
  }
});