validation 校验框架（二）-字段校验vs非字段校验

 

在我们的 -validation.xml文件里面可以有两种方式定义校验器（validator）：

1. <validator>
2. <field-validator>

当用其中任何一个是请记住一下几点：

Non-Field-Validator:  <validator>允许我们声明两种类型的校验器（a plain Validator或者 a field-specific Validator）

例如：

<validator type="expression>
<param name="expression" > foo gt bar</param>
<message> foo must be great than bar.</message>
</validator>
<validator type="required" >
<param name="fieldName" > bar</param>
<message> You must enter a value for bar.</message>
</validator>

field-validator :（这段说得太长，没看明白。）定义在一个<field-validator>的FieldValidator的filename将会被自动赋予其父节点field的fieldName的值。

建议：<field-validator>和 <validator> (其中的a field-specific Validator），两者选其一时，最好选<field-validator>，因为xml文件好看一些。

注意：<field>里面只能用<field-validator>。

举例：声明一个 FieldValidator

<field name="email_address" >
<field-validator type="required" >
<message> You cannot leave the email address field empty.</message>
</field-validator>
<field-validator type="email" >
<message> The email address you entered is not valid.</message>
</field-validator>
</field>

 

这两种是等价的：

<field name="email_address" >
<field-validator type="required" >
<message> You cannot leave the email address field empty.</message>
</field-validator>
<field-validator type="email" >
<message> The email address you entered is not valid.</message>
</field-validator>
</field>

<validator type="required" >
<param name="fieldName" > email_address</param>
<message> You cannot leave the email address field empty.</message>
</validator>
<validator type="email" >
<param name="fieldName" > email_address</param>
<message> The email address you entered is not valid.</message>
</validator>