Facebook SDK Integration Open Session Crashing - facebook-android-sdk

Question

While creating a Open Request using the Facebook SDK, i get the following error.
Error:
Caused by: java.lang.UnsupportedOperationException: Session: an attempt was made to open an already opened session.
at com.facebook.Session.open(Session.java:985)
at com.facebook.Session.openForRead(Session.java:388)
at com.photos.pixitor.activities.PhotoEffectBaseActivity.loginRequest(PhotoEffectBaseActivity.java:619)
The error does not occur If I first make the request. But after making the login request first and then cancelling the request and again main the login request , the application crashes.
Here is the Code:
OpenRequest request = new Session.OpenRequest(this);
request.setPermissions(Arrays.asList("basic_info"));
if(session.isOpened()){
session.requestNewReadPermissions(new NewPermissionsRequest(
PhotoEffectBaseActivity.this,"basic_info"));
session.addCallback(new StatusCallback() {
#Override
public void call(Session session, SessionState state, Exception exception) {
if(state.isOpened()){
Util.logd("Opened+Publishing Request");
publishPhotoRequest(session);
}
if(session.isOpened()){
Util.logd("Session is Opened");
getUserDetails(session);
}
}
});
return session;
}
Util.logd("Session Not Opened: Opening For Read");
session.openForRead(request);
Util.logd("Session is Opened for Read");
session.addCallback(new StatusCallback() {
#Override
public void call(Session session, SessionState state, Exception exception) {
if(state.isOpened()){
Util.logd("Opened+Publishing Request");
publishPhotoRequest(session);
}
if(session.isOpened()){
Util.logd("Session is Opened");
getUserDetails(session);
}
}
});

Answer 1

One thing to realize is that session opening is asynchronous (since it needs to possibly call out to the Facebook app, and get user input). So you can't make two session.open* calls in a row without waiting for the first one to return.
What's happening in your code is that you have:
if (session.isOpened()) {
// MAKE AN OPEN REQUEST
}
// MAKE ANOTHER OPEN REQUEST
This basically makes 2 open requests in a row if your session was already opened.
So how do you fix this?
First of all, the session.requestNewReadPermissions() call is unnecessary since it's only asking for "basic_info", and that comes by default, so you don't need to ask for any additional permissions. You can just remove this whole block.
Secondly, if you did want to request additional read permissions, you can just add them to the session.openForRead() method you're calling later on.
Lastly, a couple of other issues I noticed with your code: you're adding the callback AFTER you're calling session.openForRead(), this probably won't work the way you want. You'll want to add the callback to your request, and BEFORE you call openForRead. You're also trying to publish photos, and I'm not seeing any publish permissions being requested.