Lounge

Schema Extension

It is useful to have a common base schema, that all other schemas / models would extend or "inherit" properties from. This can be accomplished by using the Schema.extend function. When used all properties, virtuals, methods, statics, and middleware that are present in the base schema but not present in destination schema are copied into the destination schema.

 var baseSchema = lounge.schema({
  metadata: {
    doc_type: String,
    createdAt: Date,
    updatedAt: Date
  }
})

baseSchema.pre('save', function (next) {
  if (!this.metadata) {
    this.metadata = {}
  }

  var now = new Date()

  if (!this.metadata.createdAt) {
    this.metadata.createdAt = now
  }

  this.metadata.updatedAt = now
  this.metadata.doc_type = this.modelName

  next()
})

baseSchema.method('baseFoo', function () {
  console.log('base foo')
})

var userSchema = lounge.schema({
  name: String,
  email: String,
})

userSchema.pre('save', function (next) {
  if (this.email) {
    this.email = this.email.toLowerCase()
  }

  next()
})

userSchema.method('userFoo', function () {
  console.log('user foo')
})

// make user schema extend the base schema
userSchema.extend(baseSchema)
var User = lounge.model('User', userSchema)

user = new User({
  name: 'Bob Smith',
  email: 'BSmith@gmail.com'
})

user.baseFoo() // prints 'base foo'
user.userFoo() // prints 'user foo'

user.save(function(err, savedDoc) {
  console.log(user.metadata.updatedAt) // Sat Dec 29 2015 03:30:00 GMT-0400 (AST)
  console.log(user.metadata.doc_type) // 'user'
  console.log(user.email) // 'bsmith@gmail.com'
})

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