thoughts/node_modules/mongoose/examples/schema/schema.js

/**
 * Module dependencies.
 */

var mongoose = require('../../lib'),
    Schema = mongoose.Schema;

/**
 * Schema definition
 */

// recursive embedded-document schema

var Comment = new Schema();

Comment.add({
  title: {
    type: String,
    index: true
  },
  date: Date,
  body: String,
  comments: [Comment]
});

var BlogPost = new Schema({
  title: {
    type: String,
    index: true
  },
  slug: {
    type: String,
    lowercase: true,
    trim: true
  },
  date: Date,
  buf: Buffer,
  comments: [Comment],
  creator: Schema.ObjectId
});

var Person = new Schema({
  name: {
    first: String,
    last: String
  },
  email: {
    type: String,
    required: true,
    index: {
      unique: true,
      sparse: true
    }
  },
  alive: Boolean
});

/**
 * Accessing a specific schema type by key
 */

BlogPost.path('date')
.default(function() {
  return new Date();
})
.set(function(v) {
  return v === 'now' ? new Date() : v;
});

/**
 * Pre hook.
 */

BlogPost.pre('save', function(next, done) {
  /* global emailAuthor */
  emailAuthor(done); // some async function
  next();
});

/**
 * Methods
 */

BlogPost.methods.findCreator = function(callback) {
  return this.db.model('Person').findById(this.creator, callback);
};

BlogPost.statics.findByTitle = function(title, callback) {
  return this.find({title: title}, callback);
};

BlogPost.methods.expressiveQuery = function(creator, date, callback) {
  return this.find('creator', creator).where('date').gte(date).run(callback);
};

/**
 * Plugins
 */

function slugGenerator(options) {
  options = options || {};
  var key = options.key || 'title';

  return function slugGenerator(schema) {
    schema.path(key).set(function(v) {
      this.slug = v.toLowerCase().replace(/[^a-z0-9]/g, '').replace(/-+/g, '');
      return v;
    });
  };
}

BlogPost.plugin(slugGenerator());

/**
 * Define model.
 */

mongoose.model('BlogPost', BlogPost);
mongoose.model('Person', Person);