SchemaString

字串綱要類型建構函式。

覆寫 required 驗證器用來檢查字串是否通過 required 檢查的函式。

範例

// Allow empty strings to pass `required` check
mongoose.Schema.Types.String.checkRequired(v => v != null);

const M = mongoose.model({ str: { type: String, required: true } });
new M({ str: '' }).validateSync(); // `null`, validation passes!

取得/設定用來將任意值轉換為字串的函式。

範例

// Throw an error if you pass in an object. Normally, Mongoose allows
// objects with custom `toString()` functions.
const original = mongoose.Schema.Types.String.cast();
mongoose.Schema.Types.String.cast(v => {
  assert.ok(v == null || typeof v !== 'object');
  return original(v);
});

// Or disable casting entirely
mongoose.Schema.Types.String.cast(false);

為所有字串實例附加 getter。

範例

// Make all numbers round down
mongoose.Schema.String.get(v => v.toLowerCase());

const Model = mongoose.model('Test', new Schema({ test: String }));
new Model({ test: 'FOO' }).test; // 'foo'

檢查給定的值是否滿足 required 驗證器。如果該值是字串（即不是 null 或 undefined）且長度為正，則該值被視為有效。required 驗證器對於空字串將會失敗。

新增一個列舉驗證器

範例

const states = ['opening', 'open', 'closing', 'closed']
const s = new Schema({ state: { type: String, enum: states }})
const M = db.model('M', s)
const m = new M({ state: 'invalid' })
m.save(function (err) {
  console.error(String(err)) // ValidationError: `invalid` is not a valid enum value for path `state`.
  m.state = 'open'
  m.save(callback) // success
})

// or with custom error messages
const enum = {
  values: ['opening', 'open', 'closing', 'closed'],
  message: 'enum validator failed for path `{PATH}` with value `{VALUE}`'
}
const s = new Schema({ state: { type: String, enum: enum })
const M = db.model('M', s)
const m = new M({ state: 'invalid' })
m.save(function (err) {
  console.error(String(err)) // ValidationError: enum validator failed for path `state` with value `invalid`
  m.state = 'open'
  m.save(callback) // success
})

新增一個小寫的setter。

範例

const s = new Schema({ email: { type: String, lowercase: true }})
const M = db.model('M', s);
const m = new M({ email: 'SomeEmail@example.COM' });
console.log(m.email) // someemail@example.com
M.find({ email: 'SomeEmail@example.com' }); // Queries by 'someemail@example.com'

請注意，lowercase 不會影響正規表示式查詢

範例

// Still queries for documents whose `email` matches the regular
// expression /SomeEmail/. Mongoose does **not** convert the RegExp
// to lowercase.
M.find({ email: /SomeEmail/ });

設定正規表示式驗證器。

任何未通過 regExp.test(val) 的值都將驗證失敗。

範例

const s = new Schema({ name: { type: String, match: /^a/ }})
const M = db.model('M', s)
const m = new M({ name: 'I am invalid' })
m.validate(function (err) {
  console.error(String(err)) // "ValidationError: Path `name` is invalid (I am invalid)."
  m.name = 'apples'
  m.validate(function (err) {
    assert.ok(err) // success
  })
})

// using a custom error message
const match = [ /\.html$/, "That file doesn't end in .html ({VALUE})" ];
const s = new Schema({ file: { type: String, match: match }})
const M = db.model('M', s);
const m = new M({ file: 'invalid' });
m.validate(function (err) {
  console.log(String(err)) // "ValidationError: That file doesn't end in .html (invalid)"
})

空字串、undefined 和 null 值總是通過 match 驗證器。 如果您需要這些值，請同時啟用 required 驗證器。

const s = new Schema({ name: { type: String, match: /^a/, required: true }})

設定最大長度驗證器。

範例

const schema = new Schema({ postalCode: { type: String, maxlength: 9 })
const Address = db.model('Address', schema)
const address = new Address({ postalCode: '9512512345' })
address.save(function (err) {
  console.error(err) // validator error
  address.postalCode = '95125';
  address.save() // success
})

// custom error messages
// We can also use the special {MAXLENGTH} token which will be replaced with the maximum allowed length
const maxlength = [9, 'The value of path `{PATH}` (`{VALUE}`) exceeds the maximum allowed length ({MAXLENGTH}).'];
const schema = new Schema({ postalCode: { type: String, maxlength: maxlength })
const Address = mongoose.model('Address', schema);
const address = new Address({ postalCode: '9512512345' });
address.validate(function (err) {
  console.log(String(err)) // ValidationError: The value of path `postalCode` (`9512512345`) exceeds the maximum allowed length (9).
})

設定最小長度驗證器。

範例

const schema = new Schema({ postalCode: { type: String, minlength: 5 })
const Address = db.model('Address', schema)
const address = new Address({ postalCode: '9512' })
address.save(function (err) {
  console.error(err) // validator error
  address.postalCode = '95125';
  address.save() // success
})

// custom error messages
// We can also use the special {MINLENGTH} token which will be replaced with the minimum allowed length
const minlength = [5, 'The value of path `{PATH}` (`{VALUE}`) is shorter than the minimum allowed length ({MINLENGTH}).'];
const schema = new Schema({ postalCode: { type: String, minlength: minlength })
const Address = mongoose.model('Address', schema);
const address = new Address({ postalCode: '9512' });
address.validate(function (err) {
  console.log(String(err)) // ValidationError: The value of path `postalCode` (`9512`) is shorter than the minimum length (5).
})

新增一個 trim setter。

字串值在設定時將會被 修剪。

範例

const s = new Schema({ name: { type: String, trim: true }});
const M = db.model('M', s);
const string = ' some name ';
console.log(string.length); // 11
const m = new M({ name: string });
console.log(m.name.length); // 9

// Equivalent to `findOne({ name: string.trim() })`
M.findOne({ name: string });

請注意，trim 不會影響正規表示式查詢

範例

// Mongoose does **not** trim whitespace from the RegExp.
M.find({ name: / some name / });

新增一個大寫的 setter。

範例

const s = new Schema({ caps: { type: String, uppercase: true }})
const M = db.model('M', s);
const m = new M({ caps: 'an example' });
console.log(m.caps) // AN EXAMPLE
M.find({ caps: 'an example' }) // Matches documents where caps = 'AN EXAMPLE'

請注意，uppercase 不會影響正規表示式查詢

範例

// Mongoose does **not** convert the RegExp to uppercase.
M.find({ email: /an example/ });

此綱要類型的名稱，以防止混淆器混淆函式名稱。

為所有字串實例設定預設選項。

範例

// Make all strings have option `trim` equal to true.
mongoose.Schema.String.set('trim', true);

const User = mongoose.model('User', new Schema({ name: String }));
new User({ name: '   John Doe   ' }).name; // 'John Doe'