SchemaType.prototype.required()

Parameters

  • required «Boolean|Function|Object» enable/disable the validator, or function that returns required boolean, or options object

  • [options.isRequired] «Boolean|Function» enable/disable the validator, or function that returns required boolean

  • [options.ErrorConstructor] «Function» custom error constructor. The constructor receives 1 parameter, an object containing the validator properties.

  • [message] «String» optional custom error message

Returns:
  • «SchemaType» this

Adds a required validator to this SchemaType. The validator gets added to the front of this SchemaType’s validators array using unshift().

Example:

  1. const s = new Schema({ born: { type: Date, required: true })
  3. // or with custom error message
  5. const s = new Schema({ born: { type: Date, required: '{PATH} is required!' })
  7. // or with a function
  9. const s = new Schema({
  10.   userId: ObjectId,
  11.   username: {
  12.     type: String,
  13.     required: function() { return this.userId != null; }
  14.   }
  15. })
  17. // or with a function and a custom message
  18. const s = new Schema({
  19.   userId: ObjectId,
  20.   username: {
  21.     type: String,
  22.     required: [
  23.       function() { return this.userId != null; },
  24.       'username is required if id is specified'
  25.     ]
  26.   }
  27. })
  29. // or through the path API
  31. s.path('name').required(true);
  33. // with custom error messaging
  35. s.path('name').required(true, 'grrr :( ');
  37. // or make a path conditionally required based on a function
  38. const isOver18 = function() { return this.age >= 18; };
  39. s.path('voterRegistrationId').required(isOver18);

The required validator uses the SchemaType’s checkRequired function to determine whether a given value satisfies the required validator. By default, a value satisfies the required validator if val != null (that is, if the value is not null nor undefined). However, most built-in mongoose schema types override the default checkRequired function: