find-users-promises.js

// This API method returns a limited number of objects based on the limit, but
// it relies on the query parameters to define the pagination filtes (currently
// managed in Angular)
//
// Because it has to make three separate queries, we make use of Mongoose-Q to
// manage the promises in a way that is performant and readable
UserService.prototype.find = function(params, callback) {

  // First we parse the parameters
  var query = buildUserQuery(params);
  var sort = (params.descending ? '-' : '') + params.sort || 'displayName';
  var limit = params.limit || 30;

  // Then we will create a return object to which the functions below can add.
  var returnObject = {};

  // These "find" chains return promises
  findNextFewUsers = User
    .find(query)
    .where('deleted').ne(true)
    .sort(sort)
    .limit(limit)
    .populate('company')

  findConsultantCount = User
    .find(query)
    .where('deleted').ne(true)
    .where({accountType: 'USER'})
    .count()

  findCompanyCount = User
    .find(query)
    .where('deleted').ne(true)
    .where({accountType: 'COMPANY'})
    .count()

  // These functions handle the returned data from each promise
  function processUsers(users) {
    if (params.projectKey) {
      users = sortUsersByProjectScore(users, params.projectKey);
    }
    returnObject.users = users;
  }

  function processConsultantCount(count) {
    returnObject.numberOfCompanies = count;
  }

  function processCompanyCount(count) {
    returnObject.numberOfConsultants = count;
  };

  // And boom goes the dynamite.
  findNextFewUsers
    .execQ()
    .then(processUsers)
    .then(findConsultantCount)
    .then(processConsultantCount)
    .then(findCompanyCount)
    .then(processCompanyCount)
    .then(function() {
      callback(null, returnObject)
    })
    .catch(function(err) {
      callback(err, null);
    })
    .done();

};