[译]Mongoose指南

开始前记住下面几点

• Validation定义在SchemaType中
• Validation是一个内部的中间件
• 当document要save前会发生验证
• 验证不会发生在空值上 除非对应的字段加上了 required validator
• 可以自定义验证器

内置的验证器

• 所有的SchemaType都有required验证器
• Number有min和max验证器
• String有enum和match验证器

自定义验证器

//确保值是something
function validator(val){
 return val == "something";
}
new Schema({name:{type:String, validate: validator}});

//自定义错误信息
var custom =[validator, '{PATH} does not equal something'];
new Schema({name:{type:String, validate: custome}});

//一次添加多个验证器
var many = [
  {validator:validator, msg:'uh oh'},
  {validator: anotherValidator, msg: 'failed'}
];
new Schema({name: {type:String, validate:many});

//or
var schema = new Schema({name: 'string'});
schema.path('name').validate(validator, "{PATH} {VALUE}");

　　

var toySchema = new Schema({
  color: String,
  name: String
});

var Toy = mongoose.model('Toy', toySchema);

Toy.schema.path('color').validate(function (value) {
  return /blue|green|white|red|orange|periwinkle/i.test(value);
}, 'Invalid color');

var toy = new Toy({ color: 'grease'});

toy.save(function (err) {
  // err is our ValidationError object
  // err.errors.color is a ValidatorError object
  
  console.log(err.errors.color.message) // prints 'Validator "Invalid color" failed for path color with value `grease`'
  console.log(String(err.errors.color)) // prints 'Validator "Invalid color" failed for path color with value `grease`'
  console.log(err.errors.color.type)  // prints "Invalid color"
  console.log(err.errors.color.path)  // prints "color"
  console.log(err.errors.color.value) // prints "grease"
  console.log(err.name) // prints "ValidationError"
  console.log(err.message) // prints "Validation failed"
});

当验证发生错误的时候, document会有一个erros属性:

toy.errors.color.message == err.errors.color.message