main.js

Parse.Cloud.beforeSave(Parse.User, function(request, response) {
    Parse.Cloud.useMasterKey(); 
    var user = request.user;
    if (user.existed()) { return; }
    // set ACL so only the user himself can see his own data
    user.setACL(new Parse.ACL(user));
    user.save();
    // add user to role
    var roleName = "member";
    var roleQuery = new Parse.Query(Parse.Role);
    roleQuery.equalTo("name", roleName);
    roleQuery.first().then(function(role) {
    role.getUsers().add(user);
    // save role
    return role.save();
    });
});