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docs/guide-zh-CN/input-validation.md

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+输入验证
+================
+
+一般说来，程序猿永远不应该信任从最终用户直接接收到的数据，并且使用它们之前应始终先验证其可靠性。
+
+要给 [model](structure-models.md) 填充其所需的用户输入数据，你可以调用 [[yii\base\Model::validate()]] 方法验证它们。该方法会返回一个布尔值，指明是否通过验证。若没有通过，你能通过 [[yii\base\Model::errors]] 属性获取相应的报错信息。比如，
+
+```php
+$model = new \app\models\ContactForm;
+
+// 用用户输入来填充模型的特性
+$model->attributes = \Yii::$app->request->post('ContactForm');
+
+if ($model->validate()) {
+    // 若所有输入都是有效的
+} else {
+    // 有效性验证失败：$errors 属性就是存储错误信息的数组
+    $errors = $model->errors;
+}
+```
+
+`validate()` 方法，在幕后为执行验证操作，进行了以下步骤：
+
+1. 通过从 [[yii\base\Model::scenarios()]] 方法返回基于当前 [[yii\base\Model::scenario|场景（scenario）]] 的特性属性列表，算出哪些特性应该进行有效性验证。这些属性被称作 *active attributes*（激活特性）。
+2. 通过从 [[yii\base\Model::rules()]] 方法返回基于当前 [[yii\base\Model::scenario|场景（scenario）]] 的验证规则列表，这些规则被称作 *active rules*（激活规则）。
+3. 用每个激活规则去验证每个与之关联的激活特性。若失败，则记录下对应模型特性的错误信息。
+
+
+## 声明规则（Rules） <a name="declaring-rules"></a>
+
+要让 `validate()` 方法起作用，你需要声明与需验证模型特性相关的验证规则。为此，需要重写 [[yii\base\Model::rules()]] 方法。下面的例子展示了如何声明用于验证 `ContactForm` 模型的相关验证规则：
+
+```php
+public function rules()
+{
+    return [
+        // name，email，subject 和 body 特性是 `require`（必填）的
+        [['name', 'email', 'subject', 'body'], 'required'],
+
+        // email 特性必须是一个有效的 email 地址
+        ['email', 'email'],
+    ];
+}
+```
+
+[[yii\base\Model::rules()|rules()]] 方法应返回一个由规则所组成的数组，每一个规则都呈现为以下这类格式的小数组：
+
+```php
+[
+    // required, specifies which attributes should be validated by this rule.
+    // For a single attribute, you can use the attribute name directly
+    // without having it in an array instead of an array
+    ['attribute1', 'attribute2', ...],
+
+    // required, specifies the type of this rule.
+    // It can be a class name, validator alias, or a validation method name
+    'validator',
+
+    // optional, specifies in which scenario(s) this rule should be applied
+    // if not given, it means the rule applies to all scenarios
+    // You may also configure the "except" option if you want to apply the rule
+    // to all scenarios except the listed ones
+    'on' => ['scenario1', 'scenario2', ...],
+
+    // optional, specifies additional configurations for the validator object
+    'property1' => 'value1', 'property2' => 'value2', ...
+]
+```
+
+For each rule you must specify at least which attributes the rule applies to and what is the type of the rule.
+You can specify the rule type in one of the following forms:
+
+* the alias of a core validator, such as `required`, `in`, `date`, etc. Please refer to
+  the [Core Validators](tutorial-core-validators.md) for the complete list of core validators.
+* the name of a validation method in the model class, or an anonymous function. Please refer to the
+  [Inline Validators](#inline-validators) subsection for more details.
+* the name of a validator class. Please refer to the [Standalone Validators](#standalone-validators)
+  subsection for more details.
+
+A rule can be used to validate one or multiple attributes, and an attribute may be validated by one or multiple rules.
+A rule may be applied in certain [scenarios](structure-models.md#scenarios) only by specifying the `on` option.
+If you do not specify an `on` option, it means the rule will be applied to all scenarios.
+
+When the `validate()` method is called, it does the following steps to perform validation:
+
+1. Determine which attributes should be validated by checking the current [[yii\base\Model::scenario|scenario]]
+   against the scenarios declared in [[yii\base\Model::scenarios()]]. These attributes are the active attributes.
+2. Determine which rules should be applied by checking the current [[yii\base\Model::scenario|scenario]]
+   against the rules declared in [[yii\base\Model::rules()]]. These rules are the active rules.
+3. Use each active rule to validate each active attribute which is associated with the rule.
+
+According to the above validation steps, an attribute will be validated if and only if it is
+an active attribute declared in `scenarios()` and is associated with one or multiple active rules
+declared in `rules()`.
+
+
+### 自定义错误信息 <a name="customizing-error-messages"></a>
+
+Most validators have default error messages that will be added to the model being validated when its attributes
+fail the validation. For example, the [[yii\validators\RequiredValidator|required]] validator will add
+a message "Username cannot be blank." to a model when the `username` attribute fails the rule using this validator.
+
+You can customize the error message of a rule by specifying the `message` property when declaring the rule,
+like the following,
+
+```php
+public function rules()
+{
+    return [
+        ['username', 'required', 'message' => 'Please choose a username.'],
+    ];
+}
+```
+
+Some validators may support additional error messages to more precisely describe different causes of
+validation failures. For example, the [[yii\validators\NumberValidator|number]] validator supports
+[[yii\validators\NumberValidator::tooBig|tooBig]] and [[yii\validators\NumberValidator::tooSmall|tooSmall]]
+to describe the validation failure when the value being validated is too big and too small, respectively.
+You may configure these error messages like configuring other properties of validators in a validation rule.
+
+
+### 验证事件 <a name="validation-events"></a>
+
+When [[yii\base\Model::validate()]] is called, it will call two methods that you may override to customize
+the validation process:
+
+* [[yii\base\Model::beforeValidate()]]: the default implementation will trigger a [[yii\base\Model::EVENT_BEFORE_VALIDATE]]
+  event. You may either override this method or respond to this event to do some preprocessing work
+  (e.g. normalizing data inputs) before the validation occurs. The method should return a boolean value indicating
+  whether the validation should proceed or not.
+* [[yii\base\Model::afterValidate()]]: the default implementation will trigger a [[yii\base\Model::EVENT_AFTER_VALIDATE]]
+  event. You may either override this method or respond to this event to do some postprocessing work after
+  the validation is completed.
+
+
+### 条件式验证 <a name="conditional-validation"></a>
+
+To validate attributes only when certain conditions apply, e.g. the validation of one attribute depends
+on the value of another attribute you can use the [[yii\validators\Validator::when|when]] property
+to define such conditions. For example,
+
+```php
+[
+    ['state', 'required', 'when' => function($model) {
+        return $model->country == 'USA';
+    }],
+]
+```
+
+The [[yii\validators\Validator::when|when]] property takes a PHP callable with the following signature:
+
+```php
+/**
+ * @param Model $model the model being validated
+ * @param string $attribute the attribute being validated
+ * @return boolean whether the rule should be applied
+ */
+function ($model, $attribute)
+```
+
+If you also need to support client-side conditional validation, you should configure
+the [[yii\validators\Validator::whenClient|whenClient]] property which takes a string representing a JavaScript
+function whose return value determines whether to apply the rule or not. For example,
+
+```php
+[
+    ['state', 'required', 'when' => function ($model) {
+        return $model->country == 'USA';
+    }, 'whenClient' => "function (attribute, value) {
+        return $('#country').value == 'USA';
+    }"],
+]
+```
+
+
+### 数据过滤 <a name="data-filtering"></a>
+
+User inputs often need to be filtered or preprocessed. For example, you may want to trim the spaces around the
+`username` input. You may use validation rules to achieve this goal.
+
+The following examples shows how to trim the spaces in the inputs and turn empty inputs into nulls by using
+the [trim](tutorial-core-validators.md#trim) and [default](tutorial-core-validators.md#default) core validators:
+
+```php
+[
+    [['username', 'email'], 'trim'],
+    [['username', 'email'], 'default'],
+]
+```
+
+You may also use the more general [filter](tutorial-core-validators.md#filter) validator to perform more complex
+data filtering.
+
+As you can see, these validation rules do not really validate the inputs. Instead, they will process the values
+and save them back to the attributes being validated.
+
+
+### 处理空输入 <a name="handling-empty-inputs"></a>
+
+When input data are submitted from HTML forms, you often need to assign some default values to the inputs
+if they are empty. You can do so by using the [default](tutorial-core-validators.md#default) validator. For example,
+
+```php
+[
+    // set "username" and "email" as null if they are empty
+    [['username', 'email'], 'default'],
+
+    // set "level" to be 1 if it is empty
+    ['level', 'default', 'value' => 1],
+]
+```
+
+By default, an input is considered empty if its value is an empty string, an empty array or a null.
+You may customize the default empty detection logic by configuring the the [[yii\validators\Validator::isEmpty]] property
+with a PHP callable. For example,
+
+```php
+[
+    ['agree', 'required', 'isEmpty' => function ($value) {
+        return empty($value);
+    }],
+]
+```
+
+> Note: Most validators do not handle empty inputs if their [[yii\base\Validator::skipOnEmpty]] property takes
+  the default value true. They will simply be skipped during validation if their associated attributes receive empty
+  inputs. Among the [core validators](tutorial-core-validators.md), only the `captcha`, `default`, `filter`,
+  `required`, and `trim` validators will handle empty inputs.
+
+
+## Ad Hoc Validation <a name="ad-hoc-validation"></a>
+
+Sometimes you need to do *ad hoc validation* for values that are not bound to any model.
+
+If you only need to perform one type of validation (e.g. validating email addresses), you may call
+the [[yii\validators\Validator::validate()|validate()]] method of the desired validator, like the following:
+
+```php
+$email = 'test@example.com';
+$validator = new yii\validators\EmailValidator();
+
+if ($validator->validate($email, $error)) {
+    echo 'Email is valid.';
+} else {
+    echo $error;
+}
+```
+
+> Note: Not all validators support such kind of validation. An example is the [unique](tutorial-core-validators.md#unique)
+  core validator which is designed to work with a model only.
+
+If you need to perform multiple validations against several values, you can use [[yii\base\DynamicModel]]
+which supports declaring both attributes and rules on the fly. Its usage is like the following:
+
+```php
+public function actionSearch($name, $email)
+{
+    $model = DynamicModel::validateData(compact('name', 'email'), [
+        [['name', 'email'], 'string', 'max' => 128],
+        ['email', 'email'],
+    ]);
+
+    if ($model->hasErrors()) {
+        // validation fails
+    } else {
+        // validation succeeds
+    }
+}
+```
+
+The [[yii\base\DynamicModel::validateData()]] method creates an instance of `DynamicModel`, defines the attributes
+using the given data (`name` and `email` in this example), and then calls [[yii\base\Model::validate()]]
+with the given rules.
+
+Alternatively, you may use the following more "classic" syntax to perform ad hoc data validation:
+
+```php
+public function actionSearch($name, $email)
+{
+    $model = new DynamicModel(compact('name', 'email'));
+    $model->addRule(['name', 'email'], 'string', ['max' => 128])
+        ->addRule('email', 'email')
+        ->validate();
+
+    if ($model->hasErrors()) {
+        // validation fails
+    } else {
+        // validation succeeds
+    }
+}
+```
+
+After validation, you can check if the validation succeeds or not by calling the
+[[yii\base\DynamicModel::hasErrors()|hasErrors()]] method, and then get the validation errors from the
+[[yii\base\DynamicModel::errors|errors]] property, like you do with a normal model.
+You may also access the dynamic attributes defined through the model instance, e.g.,
+`$model->name` and `$model->email`.
+
+
+## 创建验证器（Validators） <a name="creating-validators"></a>
+
+Besides using the [core validators](tutorial-core-validators.md) included in the Yii releases, you may also
+create your own validators. You may create inline validators or standalone validators.
+
+
+### 行内验证器（Inline Validators） <a name="inline-validators"></a>
+
+An inline validator is one defined in terms of a model method or an anonymous function. The signature of
+the method/function is:
+
+```php
+/**
+ * @param string $attribute the attribute currently being validated
+ * @param array $params the additional name-value pairs given in the rule
+ */
+function ($attribute, $params)
+```
+
+If an attribute fails the validation, the method/function should call [[yii\base\Model::addError()]] to save
+the error message in the model so that it can be retrieved back later to present to end users.
+
+Below are some examples:
+
+```php
+use yii\base\Model;
+
+class MyForm extends Model
+{
+    public $country;
+    public $token;
+
+    public function rules()
+    {
+        return [
+            // an inline validator defined as the model method validateCountry()
+            ['country', 'validateCountry'],
+
+            // an inline validator defined as an anonymous function
+            ['token', function ($attribute, $params) {
+                if (!ctype_alnum($this->$attribute)) {
+                    $this->addError($attribute, 'The token must contain letters or digits.');
+                }
+            }],
+        ];
+    }
+
+    public function validateCountry($attribute, $params)
+    {
+        if (!in_array($this->$attribute, ['USA', 'Web'])) {
+            $this->addError($attribute, 'The country must be either "USA" or "Web".');
+        }
+    }
+}
+```
+
+> Note: By default, inline validators will not be applied if their associated attributes receive empty inputs
+  or if they have already failed some validation rules. If you want to make sure a rule is always applied,
+  you may configure the [[yii\validators\Validator::skipOnEmpty|skipOnEmpty]] and/or [[yii\validators\Validator::skipOnError|skipOnError]]
+  properties to be false in the rule declarations. For example:
+> ```php
+[
+    ['country', 'validateCountry', 'skipOnEmpty' => false, 'skipOnError' => false],
+]
+```
+
+
+### 独立验证器（Standalone Validators） <a name="standalone-validators"></a>
+
+A standalone validator is a class extending [[yii\validators\Validator]] or its child class. You may implement
+its validation logic by overriding the [[yii\validators\Validator::validateAttribute()]] method. If an attribute
+fails the validation, call [[yii\base\Model::addError()]] to save the error message in the model, like you do
+with [inline validators](#inline-validators). For example,
+
+```php
+namespace app\components;
+
+use yii\validators\Validator;
+
+class CountryValidator extends Validator
+{
+    public function validateAttribute($model, $attribute)
+    {
+        if (!in_array($model->$attribute, ['USA', 'Web'])) {
+            $this->addError($attribute, 'The country must be either "USA" or "Web".');
+        }
+    }
+}
+```
+
+If you want your validator to support validating a value without a model, you should also override
+[[yii\validators\Validator::validate()]]. You may also override [[yii\validators\Validator::validateValue()]]
+instead of `validateAttribute()` and `validate()` because by default the latter two methods are implemented
+by calling `validateValue()`.
+
+
+## 客户端验证器（Client-Side Validation） <a name="client-side-validation"></a>
+
+Client-side validation based on JavaScript is desirable when end users provide inputs via HTML forms, because
+it allows users to find out input errors faster and thus provides better user experience. You may use or implement
+a validator that supports client-side validation *in addition to* server-side validation.
+
+> Info: While client-side validation is desirable, it is not a must. It main purpose is to provider users better
+  experience. Like input data coming from end users, you should never trust client-side validation. For this reason,
+  you should always perform server-side validation by calling [[yii\base\Model::validate()]], like
+  described in the previous subsections.
+
+
+### 使用客户端验证 <a name="using-client-side-validation"></a>
+
+Many [core validators](tutorial-core-validators.md) support client-side validation out-of-box. All you need to do
+is just to use [[yii\widgets\ActiveForm]] to build your HTML forms. For example, `LoginForm` below declares two
+rules: one uses the [required](tutorial-core-validators.md#required) core validator which is supported on both
+client and server sides; the other uses the `validatePassword` inline validator which is only supported on the server
+side.
+
+```php
+namespace app\models;
+
+use yii\base\Model;
+use app\models\User;
+
+class LoginForm extends Model
+{
+    public $username;
+    public $password;
+
+    public function rules()
+    {
+        return [
+            // username and password are both required
+            [['username', 'password'], 'required'],
+
+            // password is validated by validatePassword()
+            ['password', 'validatePassword'],
+        ];
+    }
+
+    public function validatePassword()
+    {
+        $user = User::findByUsername($this->username);
+
+        if (!$user || !$user->validatePassword($this->password)) {
+            $this->addError('password', 'Incorrect username or password.');
+        }
+    }
+}
+```
+
+The HTML form built by the following code contains two input fields `username` and `password`.
+If you submit the form without entering anything, you will find the error messages requiring you
+to enter something appear right away without any communication with the server.
+
+```php
+<?php $form = yii\widgets\ActiveForm::begin(); ?>
+    <?= $form->field($model, 'username') ?>
+    <?= $form->field($model, 'password')->passwordInput() ?>
+    <?= Html::submitButton('Login') ?>
+<?php yii\widgets\ActiveForm::end(); ?>
+```
+
+Behind the scene, [[yii\widgets\ActiveForm]] will read the validation rules declared in the model
+and generate appropriate JavaScript code for validators that support client-side validation. When a user
+changes the value of an input field or submit the form, the client-side validation JavaScript will be triggered.
+
+If you want to turn off client-side validation completely, you may configure the
+[[yii\widgets\ActiveForm::enableClientValidation]] property to be false. You may also turn off client-side
+validation of individual input fields by configuring their [[yii\widgets\ActiveField::enableClientValidation]]
+property to be false.
+
+
+### 实现客户端验证 <a name="implementing-client-side-validation"></a>
+
+To create a validator that supports client-side validation, you should implement the
+[[yii\validators\Validator::clientValidateAttribute()]] method which returns a piece of JavaScript code
+that performs the validation on the client side. Within the JavaScript code, you may use the following
+predefined variables:
+
+- `attribute`: the name of the attribute being validated.
+- `value`: the value being validated.
+- `messages`: an array used to hold the validation error messages for the attribute.
+
+In the following example, we create a `StatusValidator` which validates if an input is a valid status input
+against the existing status data. The validator supports both server side and client side validation.
+
+```php
+namespace app\components;
+
+use yii\validators\Validator;
+use app\models\Status;
+
+class StatusValidator extends Validator
+{
+    public function init()
+    {
+        parent::init();
+        $this->message = 'Invalid status input.';
+    }
+
+    public function validateAttribute($model, $attribute)
+    {
+        $value = $model->$attribute;
+        if (!Status::find()->where(['id' => $value])->exists()) {
+            $model->addError($attribute, $this->message);
+        }
+    }
+
+    public function clientValidateAttribute($model, $attribute, $view)
+    {
+        $statuses = json_encode(Status::find()->select('id')->asArray()->column());
+        $message = json_encode($this->message);
+        return <<<JS
+if (!$.inArray(value, $statuses)) {
+    messages.push($message);
+}
+JS;
+    }
+}
+```
+
+> Tip: The above code is given mainly to demonstrate how to support client-side validation. In practice,
+  you may use the [in](tutorial-core-validators.md#in) core validator to achieve the same goal. You may
+  write the validation rule like the following:
+> ```php
+[
+    ['status', 'in', 'range' => Status::find()->select('id')->asArray()->column()],
+]
+```

docs/guide-zh-CN/tutorial-core-validators.md

@@ -0,0 +1,486 @@
+核心验证器（Core Validators）
+===============
+
+Yii 提供一系列常用的核心验证器，主要存在于 `yii\validators` 命名空间之下。为了避免使用冗长的类名，你可以直接用**昵称**来指定相应的核心验证器。比如你可以用 `required` 昵称代指 [[yii\validators\RequiredValidator]] 类：
+
+```php
+public function rules()
+{
+    return [
+        [['email', 'password'], 'required'],
+    ];
+}
+```
+
+[[yii\validators\Validator::builtInValidators]] 属性声明了所有被支持的验证器昵称。
+
+下面，我们将详细介绍每一款验证器的主要用法和属性。
+
+
+## [[yii\validators\BooleanValidator|boolean（布尔型）]] <a name="boolean"></a>
+
+```php
+[
+    // 检查 "selected" 是否为 0 或 1，无视数据类型
+    ['selected', 'boolean'],
+
+    // 检查 "deleted" 是否为布尔类型，即 true 或 false
+    ['deleted', 'boolean', 'trueValue' => true, 'falseValue' => false, 'strict' => true],
+]
+```
+
+该验证器检查输入值是否为一个布尔值。
+
+- `trueValue`： 代表**真**的值。默认为 `'1'`。
+- `falseValue`：代表**假**的值。默认为 `'0'`。
+- `strict`：是否要求待测输入必须严格匹配 `trueValue` 或 `falseValue`。默认为 `false`。
+
+
+> 注意：因为通过 HTML 表单传递的输入数据都是字符串类型，所以一般情况下你都需要保持
+  [[yii\validators\BooleanValidator::strict|strict]] 属性为假。
+
+
+## [[yii\captcha\CaptchaValidator|captcha（验证码）]] <a name="captcha"></a>
+
+```php
+[
+    ['verificationCode', 'captcha'],
+]
+```
+
+该验证器通常配合 [[yii\captcha\CaptchaAction]] 以及 [[yii\captcha\Captcha]]
+使用，以确保某一输入与 [[yii\captcha\Captcha|CAPTCHA]] 小部件所显示的验证代码（verification code）相同。
+
+- `caseSensitive`：对验证代码的比对是否要求大小写敏感。默认为 false。
+- `captchaAction`：指向用于渲染 CAPTCHA 图片的 [[yii\captcha\CaptchaAction|CAPTCHA action]] 的 [路由](structure-controllers.md#routes)。默认为 `'site/captcha'`。
+- `skipOnEmpty`：当输入为空时，是否跳过验证。默认为 false，也就是输入值为必需项。
+  
+
+## [[yii\validators\CompareValidator|compare（比较）]] <a name="compare"></a>
+
+```php
+[
+    // 检查 "password" 特性的值是否与 "password_repeat" 的值相同
+    ['password', 'compare'],
+
+    // 检查年龄是否大于等于 30
+    ['age', 'compare', 'compareValue' => 30, 'operator' => '>='],
+]
+```
+
+该验证器比较两个特定输入值之间的关系是否与 `operator` 属性所指定的相同。
+
+- `compareAttribute`：用于与原特性相比较的特性名称。当该验证器被用于验证某目标特性时，该属性会默认为目标属性加后缀 `_repeat`。举例来说，若目标特性为 `password`，则该属性默认为 `password_repeat`。
+- `compareValue`：用于与输入值相比较的常量值。当该属性与 `compareAttribute` 属性同时被指定时，该属性优先被使用。
+- `operator`：比较操作符。默认为 `==`，意味着检查输入值是否与 `compareAttribute` 或 `compareValue` 的值相等。该属性支持如下操作符：
+     * `==`：检查两值是否相等。比对为非严格模式。
+     * `===`：检查两值是否相等。比对为严格模式。
+     * `!=`：检查两值是否不等。 比对为非严格模式。
+     * `!==`：检查两值是否不等。比对为严格模式。
+     * `>`：检查待测目标值是否大于给定被测值。
+     * `>=`：检查待测目标值是否大于等于给定被测值。
+     * `<`：检查待测目标值是否小于给定被测值。
+     * `<=`：检查待测目标值是否小于等于给定被测值。
+
+
+## [[yii\validators\DateValidator|date（日期）]] <a name="date"></a>
+
+```php
+[
+    [['from', 'to'], 'date'],
+]
+```
+
+该验证器检查输入值是否为适当格式的 date，time，或者 datetime。另外，它还可以帮你把输入值转换为一个 UNIX 时间戳并保存到 [[yii\validators\DateValidator::timestampAttribute|timestampAttribute]] 属性所指定的特性里。
+
+- `format`：待测的 日期/时间 格式。请参考
+  [date_create_from_format() 相关的 PHP 手册](http://www.php.net/manual/zh/datetime.createfromformat.php)
+  了解设定格式字符串的更多细节。默认值为 `'Y-m-d'`。
+- `timestampAttribute`：用于保存由输入时间/日期所转换的 UNIX 时间戳的特性名称。
+
+
+## [[yii\validators\DefaultValueValidator|default（默认值）]] <a name="default"></a>
+
+```php
+[
+    // 若 "age" 为空，则将其设为 null
+    ['age', 'default', 'value' => null],
+
+    // 若 "country" 为空，则将其设为 "USA"
+    ['country', 'default', 'value' => 'USA'],
+
+    // 若 "from" 和 "to" 为空，则分别给他们分配自今天起，3 天后和 6 天后的日期。
+    [['from', 'to'], 'default', 'value' => function ($model, $attribute) {
+        return date('Y-m-d', strtotime($attribute === 'to' ? '+3 days' ：'+6 days'));
+    }],
+]
+```
+
+该验证器并不检查数据。而是，给为空的待测特性分配默认值。
+
+- `value`：默认值，或一个返回默认值的 PHP Callable 对象（即回调函数）。它们会分配给检测为空的待测特性。PHP 回调方法的样式如下：
+
+```php
+function foo($model, $attribute) {
+    // ... compute $value ...
+    return $value;
+}
+```
+
+> 补充：如何判断待测值是否为空，被写在另外一个话题的[处理空输入](input-validation.md#handling-empty-inputs)章节。
+
+
+## [[yii\validators\NumberValidator|double（双精度浮点型）]] <a name="double"></a>
+
+```php
+[
+    // 检查 "salary" 是否为浮点数
+    ['salary', 'double'],
+]
+```
+
+该验证器检查输入值是否为双精度浮点数。他等效于 [number](#number) 验证器。
+
+- `max`：上限值（含界点）。若不设置，则验证器不检查上限。
+- `min`：下限值（含界点）。若不设置，则验证器不检查下限。
+
+
+## [[yii\validators\EmailValidator|email（电子邮件）]] <a name="email"></a>
+
+```php
+[
+    // 检查 "email" 是否为有效的邮箱地址
+    ['email', 'email'],
+]
+```
+
+该验证器检查输入值是否为有效的邮箱地址。
+
+- `allowName`：检查是否允许带名称的电子邮件地址 (e.g. `张三 <John.san@example.com>`)。 默认为 false。
+- `checkDNS`：检查邮箱域名是否存在，且有没有对应的 A 或 MX 记录。不过要知道，有的时候该项检查可能会因为临时性 DNS 故障而失败，哪怕它其实是有效的。默认为 false。
+- `enableIDN`：验证过程是否应该考虑 IDN（internationalized domain names，国际化域名，也称多语种域名，比如中文域名）。
+  默认为 false。要注意但是为使用 IDN 验证功能，请先确保安装并开启 `intl` PHP 扩展，不然会导致抛出异常。
+
+
+## [[yii\validators\ExistValidator|exist（存在）]] <a name="exist"></a>
+
+```php
+[
+    // a1 needs to exist in the column represented by the "a1" attribute
+    ['a1', 'exist'],
+
+    // a1 needs to exist, but its value will use a2 to check for the existence
+    ['a1', 'exist', 'targetAttribute' => 'a2'],
+
+    // a1 and a2 need to exist together, and they both will receive error message
+    [['a1', 'a2'], 'exist', 'targetAttribute' => ['a1', 'a2']],
+
+    // a1 and a2 need to exist together, only a1 will receive error message
+    ['a1', 'exist', 'targetAttribute' => ['a1', 'a2']],
+
+    // a1 needs to exist by checking the existence of both a2 and a3 (using a1 value)
+    ['a1', 'exist', 'targetAttribute' => ['a2', 'a1' => 'a3']],
+
+    // a1 needs to exist. If a1 is an array, then every element of it must exist.
+    ['a1', 'exist', 'allowArray' => true],
+]
+```
+
+该验证器检查输入值是否在表字段中存在。它只对[活动记录](db-active-record.md)模型的特性起作用。它支持对一个或多过字段的验证。
+
+- `targetClass`：the name of the [Active Record](db-active-record.md) class that should be used
+  to look for the input value being validated. If not set, the class of the model currently being validated will be used.
+- `targetAttribute`：the name of the attribute in `targetClass` that should be used to validate the existence
+  of the input value. If not set, it will use the name of the attribute currently being validated.
+  You may use an array to validate the existence of multiple columns at the same time. The array values
+  are the attributes that will be used to validate the existence, while the array keys are the attributes
+  whose values are to be validated. If the key and the value are the same, you can just specify the value.
+- `filter`：additional filter to be applied to the DB query used to check the existence of the input value.
+  This can be a string or an array representing the additional query condition (refer to [[yii\db\Query::where()]]
+  on the format of query condition), or an anonymous function with the signature `function ($query)`, where `$query`
+  is the [[yii\db\Query|Query]] object that you can modify in the function.
+- `allowArray`：whether to allow the input value to be an array. 默认为 false. If this property is true
+  and the input is an array, then every element of the array must exist in the target column. Note that
+  this property cannot be set true if you are validating against multiple columns by setting `targetAttribute` as an array.
+
+
+## [[yii\validators\FileValidator|file]] <a name="file"></a>
+
+```php
+[
+    // checks if "primaryImage" is an uploaded image file in PNG, JPG or GIF format.
+    // the file size must be less than 1MB
+    ['primaryImage', 'file', 'extensions' => ['png', 'jpg', 'gif'], 'maxSize' => 1024*1024*1024],
+]
+```
+
+This validator checks if the input is a valid uploaded file.
+
+- `extensions`：a list of file name extensions that are allowed to be uploaded. This can be either
+  an array or a string consisting of file extension names separated by space or comma (e.g. "gif, jpg").
+  Extension names are case-insensitive. 默认为 null, meaning all file name
+  extensions are allowed.
+- `mimeTypes`：a list of file MIME types that are allowed to be uploaded. This can be either an array
+  or a string consisting of file MIME types separated by space or comma (e.g. "image/jpeg, image/png").
+  Mime type names are case-insensitive. 默认为 null, meaning all MIME types are allowed.
+- `minSize`：the minimum number of bytes required for the uploaded file. 默认为 null, meaning no lower limit.
+- `maxSize`：the maximum number of bytes allowed for the uploaded file. 默认为 null, meaning no upper limit.
+- `maxFiles`：the maximum number of files that the given attribute can hold. 默认为 1, meaning
+  the input must be a single uploaded file. If it is greater than 1, then the input must be an array
+  consisting of at most `maxFiles` number of uploaded files.
+- `checkExtensionByMimeType`：whether to check the file extension by the file's MIME type. If the extension produced by
+  MIME type check differs from the uploaded file extension, the file will be considered as invalid. 默认为 true,
+  meaning perform such check.
+
+`FileValidator` is used together with [[yii\web\UploadedFile]]. Please refer to the [Uploading Files](input-file-upload.md)
+section for complete coverage about uploading files and performing validation about the uploaded files.
+
+
+## [[yii\validators\FilterValidator|filter]] <a name="filter"></a>
+
+```php
+[
+    // trim "username" and "email" inputs
+    [['username', 'email'], 'filter', 'filter' => 'trim', 'skipOnArray' => true],
+
+    // normalize "phone" input
+    ['phone', 'filter', 'filter' => function ($value) {
+        // normalize phone input here
+        return $value;
+    }],
+]
+```
+
+This validator does not validate data. Instead, it applies a filter on the input value and assigns it
+back to the attribute being validated.
+
+- `filter`：a PHP callback that defines a filter. This can be a global function name, an anonymous function, etc.
+  The function signature must be `function ($value) { return $newValue; }`. This property must be set.
+- `skipOnArray`：whether to skip the filter if the input value is an array. 默认为 false.
+  Note that if the filter cannot handle array input, you should set this property to be true. Otherwise some
+  PHP error might occur.
+
+> Tip：If you want to trim input values, you may directly use [trim](#trim) validator.
+
+
+## [[yii\validators\ImageValidator|image]] <a name="image"></a>
+
+```php
+[
+    // checks if "primaryImage" is a valid image with proper size
+    ['primaryImage', 'image', 'extensions' => 'png, jpg',
+        'minWidth' => 100, 'maxWidth' => 1000,
+        'minHeight' => 100, 'maxHeight' => 1000,
+    ],
+]
+```
+
+This validator checks if the input value represents a valid image file. It extends from the [file](#file) validator
+and thus inherits all its properties. Besides, it supports the following additional properties specific for image
+validation purpose:
+
+- `minWidth`：the minimum width of the image. 默认为 null, meaning no lower limit.
+- `maxWidth`：the maximum width of the image. 默认为 null, meaning no upper limit.
+- `minHeight`：the minimum height of the image. 默认为 null, meaning no lower limit.
+- `maxHeight`：the maximum height of the image. 默认为 null, meaning no upper limit.
+
+
+## [[yii\validators\RangeValidator|in]] <a name="in"></a>
+
+```php
+[
+    // checks if "level" is 1, 2 or 3
+    ['level', 'in', 'range' => [1, 2, 3]],
+]
+```
+
+This validator checks if the input value can be found among the given list of values.
+
+- `range`：a list of given values within which the input value should be looked for.
+- `strict`：whether the comparison between the input value and the given values should be strict
+  (both the type and value must be the same). 默认为 false.
+- `not`：whether the validation result should be inverted. 默认为 false. When this property is set true,
+  the validator checks if the input value is NOT among the given list of values.
+- `allowArray`：whether to allow the input value to be an array. When this is true and the input value is an array,
+  every element in the array must be found in the given list of values, or the validation would fail.
+
+
+## [[yii\validators\NumberValidator|integer]] <a name="integer"></a>
+
+```php
+[
+    // checks if "age" is an integer
+    ['age', 'integer'],
+]
+```
+
+This validator checks if the input value is an integer.
+
+- `max`：the upper limit (inclusive) of the value. If not set, it means the validator does not check the upper limit.
+- `min`：the lower limit (inclusive) of the value. If not set, it means the validator does not check the lower limit.
+
+
+## [[yii\validators\RegularExpressionValidator|match]] <a name="match"></a>
+
+```php
+[
+    // checks if "username" starts with a letter and contains only word characters
+    ['username', 'match', 'pattern' => '/^[a-z]\w*$/i']
+]
+```
+
+This validator checks if the input value matches the specified regular expression.
+
+- `pattern`：the regular expression that the input value should match. This property must be set,
+  or an exception will be thrown.
+- `not`：whether to invert the validation result. 默认为 false, meaning the validation succeeds
+   only if the input value matches the pattern. If this is set true, the validation is considered
+   successful only if the input value does NOT match the pattern.
+
+
+## [[yii\validators\NumberValidator|number]] <a name="number"></a>
+
+```php
+[
+    // checks if "salary" is a number
+    ['salary', 'number'],
+]
+```
+
+This validator checks if the input value is a number. It is equivalent to the [double](#double] validator.
+
+- `max`：the upper limit (inclusive) of the value. If not set, it means the validator does not check the upper limit.
+- `min`：the lower limit (inclusive) of the value. If not set, it means the validator does not check the lower limit.
+
+
+## [[yii\validators\RequiredValidator|required]] <a name="required"></a>
+
+```php
+[
+    // checks if both "username" and "password" are not empty
+    [['username', 'password'], 'required'],
+]
+```
+
+This validator checks if the input value is provided and not empty.
+
+- `requiredValue`：the desired value that the input should be. If not set, it means the input should not be empty.
+- `strict`：whether to check data types when validating a value. 默认为 false.
+  When `requiredValue` is not set, if this property is true, the validator will check if the input value is
+  not strictly null; If this property is false, the validator will use a loose rule to determine a value is empty or not.
+  When `requiredValue` is set, the comparison between the input and `requiredValue` will also check data types
+  if this property is true.
+
+> Info：How to determine if a value is empty or not is a separate topic covered
+  in the [Empty Values](input-validation.md#empty-values) section.
+
+
+## [[yii\validators\SafeValidator|safe]] <a name="safe"></a>
+
+```php
+[
+    // marks "description" to be a safe attribute
+    ['description', 'safe'],
+]
+```
+
+This validator does not perform data validation. Instead, it is used to mark an attribute to be
+a [safe attribute](structure-models.md#safe-attributes).
+
+
+## [[yii\validators\StringValidator|string]] <a name="string"></a>
+
+```php
+[
+    // checks if "username" is a string whose length is between 4 and 24
+    ['username', 'string', 'length' => [4, 24]],
+]
+```
+
+This validator checks if the input value
+
+Validates that the attribute value is of certain length.
+
+- `length`：specifies the length limit of the input string being validated. This can be specified
+   in one of the following forms:
+     * an integer：the exact length that the string should be of;
+     * an array of one element：the minimum length of the input string (e.g. `[8]`). This will overwrite `min`.
+     * an array of two elements：the minimum and maximum lengths of the input string (e.g. `[8, 128]`)`.
+     This will overwrite both `min` and `max`.
+- `min`：the minimum length of the input string. If not set, it means no minimum length limit.
+- `max`：the maximum length of the input string. If not set, it means no maximum length limit.
+- `encoding`：the encoding of the input string to be validated. If not set, it will use the application's
+  [[yii\base\Application::charset|charset]] value which defaults to `UTF-8`.
+
+
+## [[yii\validators\FilterValidator|trim]] <a name="trim"></a>
+
+```php
+[
+    // trims the white spaces surrounding "username" and "email"
+    [['username', 'email'], 'trim'],
+]
+```
+
+This validator does not perform data validation. Instead, it will trim the surrounding white spaces around
+the input value. Note that if the input value is an array, it will be ignored by this validator.
+
+
+## [[yii\validators\UniqueValidator|unique]] <a name="unique"></a>
+
+```php
+[
+    // a1 needs to be unique in the column represented by the "a1" attribute
+    ['a1', 'unique'],
+
+    // a1 needs to be unique, but column a2 will be used to check the uniqueness of the a1 value
+    ['a1', 'unique', 'targetAttribute' => 'a2'],
+
+    // a1 and a2 need to be unique together, and they both will receive error message
+    [['a1', 'a2'], 'unique', 'targetAttribute' => ['a1', 'a2']],
+
+    // a1 and a2 need to be unique together, only a1 will receive error message
+    ['a1', 'unique', 'targetAttribute' => ['a1', 'a2']],
+
+    // a1 needs to be unique by checking the uniqueness of both a2 and a3 (using a1 value)
+    ['a1', 'unique', 'targetAttribute' => ['a2', 'a1' => 'a3']],
+]
+```
+
+This validator checks if the input value is unique in a table column. It only works
+with [Active Record](db-active-record.md) model attributes. It supports validation against
+either a single column or multiple columns.
+
+- `targetClass`：the name of the [Active Record](db-active-record.md) class that should be used
+  to look for the input value being validated. If not set, the class of the model currently being validated will be used.
+- `targetAttribute`：the name of the attribute in `targetClass` that should be used to validate the uniqueness
+  of the input value. If not set, it will use the name of the attribute currently being validated.
+  You may use an array to validate the uniqueness of multiple columns at the same time. The array values
+  are the attributes that will be used to validate the uniqueness, while the array keys are the attributes
+  whose values are to be validated. If the key and the value are the same, you can just specify the value.
+- `filter`：additional filter to be applied to the DB query used to check the uniqueness of the input value.
+  This can be a string or an array representing the additional query condition (refer to [[yii\db\Query::where()]]
+  on the format of query condition), or an anonymous function with the signature `function ($query)`, where `$query`
+  is the [[yii\db\Query|Query]] object that you can modify in the function.
+
+
+## [[yii\validators\UrlValidator|url]] <a name="url"></a>
+
+```php
+[
+    // checks if "website" is a valid URL. Prepend "http://" to the "website" attribute
+    // if it does not have a URI scheme
+    ['website', 'url', 'defaultScheme' => 'http'],
+]
+```
+
+This validator checks if the input value is a valid URL.
+
+- `validSchemes`：an array specifying the URI schemes that should be considered valid. 默认为 `['http', 'https']`,
+  meaning both `http` and `https` URLs are considered to be valid.
+- `defaultScheme`：the default URI scheme to be prepended to the input if it does not have the scheme part.
+  默认为 null, meaning do not modify the input value.
+- `enableIDN`：whether the validator should take into account IDN (internationalized domain names).
+  默认为 false. Note that in order to use IDN validation you have to install and enable the `intl` PHP
+  extension, otherwise an exception would be thrown.
+