Determine whether a logged in user is in a particular role

custom_roles.js

//Register the Manager role
  var Role = app.models.Role;

  Role.registerResolver('manager', function(role, context, cb) {
    function reject(err) {
       if (err) {
         return cb(err);
       }
       cb(null, false);
     }
     function isEmployeeAManagerForOrganization(userId, organisationId){
       var Employee = app.models.employee;
       Employee.findOne({where: {and: [{employeeID : userId},{organisationId : organisationId}]}}, 
       function (err, employee) {
         if (err || (employee === null)) {
           return reject(err);
         }
         cb(null, employee.isManager);
       });
     }

     if ((context.modelName !== 'organisation') && (context.modelName !== 'voucher')) {
       // the target model is not organization or voucher
       return reject();
     }
     var userId = context.accessToken.userId;
     if (!userId) {
       return reject(); // do not allow anonymous users
     }
     //Access to the level of a single organisation
     if (context.modelId === undefined){
       return reject();
     }
     switch(context.modelName){
       case 'organisation':
         context.model.findById(context.modelId, function (err, organisation) {
           if (err || (organisation === null)) {
             reject(err);
           }
           isEmployeeAManagerForOrganization(userId, organisation.id)
         });
         break;
       case 'voucher':
         context.model.findById(context.modelId, function(err, voucher) {
           if (err || voucher === null) {
             reject(err);
           }
           isEmployeeAManagerForOrganization(userId, voucher.organisationId);
         });
         break;
       default :
         reject("Unknown model");
     }

   });