title: Mongoose delete array element in document and save
body: <p>I have an array in my model document.  I would like to delete elements in that array based on a key I provide and then update MongoDB.  Is this possible?</p>
  
  <p>Here's my attempt: </p>
  
  <pre><code>var mongoose = require('mongoose'),
      Schema = mongoose.Schema;
  
  var favorite = new Schema({
      cn: String,
      favorites: Array
  });
  
  module.exports = mongoose.model('Favorite', favorite, 'favorite');
  
  exports.deleteFavorite = function (req, res, next) {
      if (req.params.callback !== null) {
          res.contentType = 'application/javascript';
      }
      Favorite.find({cn: req.params.name}, function (error, docs) {
          var records = {'records': docs};
          if (error) {
              process.stderr.write(error);
          }
          docs[0]._doc.favorites.remove({uid: req.params.deleteUid});
  
          Favorite.save(function (error, docs) {
              var records = {'records': docs};
              if (error) {
                  process.stderr.write(error);
              }
              res.send(records);
  
              return next();
          });
      });
  };
  </code></pre>
  
  <p>So far it finds the document but the remove nor save works.</p>