Check if user posted (or cancelled) sharing to Facebook in Share Dialog using FB.ui

Question

I'm using a share dialog and I want something to occur after the user posts something to his/her timeline. Right now I'm using:

function shareToFB(myName, myLink) {
    $('.overlay-bg').hide();
    FB.ui({
        method: 'share',
        href: myLink,
        name: myName
    }, function(response) {
        if (response && !response.error_code) {
            alert("Something");
        } else {
            alert("Error");
        }
    }
    );
}

But this causes "Something" to show up even when the user cancels posting. Is there any way I can find if the user has posted the message to his/her timeline without requiring any permissions. I won't mind if this requires me to use a different method of sharing (like a feed dialog).

Answer 1

Use Feed Dialog instead.

Despite its UI being ugly, successful sharing via Feed Dialog will return a response object like {post_id: "10206702999763274_10206703017843726"} regardless of user authenticating your Facebook app or not, while pressing cancel will return a null and closing popup will return undefined.

You can test this behaviour by going to your normal Facebook user profile settings and try removing your app from allowed list.

This is in contrast to the Share Dialog, which, if your app has not been authenticated by user, will return an empty response object {} regardless of successful sharing or not.

Furthermore, if you use the direct url redirect method instead of js SDK, when the user press cancel on the share page you will receive a GET parameter error_code and error_message appended to your redirect target.

[From December 2015] => Use Feed Dialog or the Share Dialog to access the post ID in the response. To achieve this the user must have logged into your app and granted it publish_actions. https://developers.facebook.com/docs/sharing/reference/share-dialog#response

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NOTE: This is true for the time of this writing (API v2.3). However as Facebook is notorious for breaking API behaviour, you should test it yourself first.

Answer 2

According to the docs, the response is the object_id of the posted entry - and it is only filled if the user authorized the App. Meaning, you can´t detect if a user really posted something if the user is not authorized.

Source: https://developers.facebook.com/docs/sharing/reference/share-dialog