如何使用架构基于属性值验证元素? [英] How can you validate Elements based on an attribute Value using a Schema?

问题描述

我要验证的 XML 如下:

<元素属性="foo"><酒吧/></元素><元素属性=你好"><世界/></元素></root>

如何使用架构进行验证?

注意:

元素只能在attribute="foo"时包含bar.

element 只能包含 world 当 attribute="hello"

解决方案

您不能在 XML Schema 1.0 中执行此操作.在 XML Schema 1.1 中，您将能够使用 <xs:assert> 元素来做这件事，但我猜你想要一些你现在可以使用的东西.

您可以使用 Schematron 作为第二层验证，允许您测试关于您的 XML 文档.有一篇关于在 XSD 中嵌入 Schematron 的相当老的文章，您可能会觉得有帮助.>

你会做这样的事情:

<report test="@attribute = 'foo' and *[not(self::bar)]">这个元素的属性是 'foo' 但它包含一个不是 bar 的元素.</报告><report test="@attribute = 'hello' and *[not(self::world)]">这个元素的属性是 'hello' 但它包含一个不是世界的元素.</报告></规则>

当然，您也可以切换到 RELAX NG，它会在睡眠中执行此操作:

<元素名称="元素"><选择><组><attribute name="attribute"><value>foo</value></attribute><element name="bar"><empty/></element></组><组><attribute name="attribute"><value>hello</value></attribute><element name="world"><empty/></element></组></元素>

The XML I'm trying to validate is as follows:

<root>
    <element attribute="foo">
        <bar/>
    </element>
    <element attribute="hello">
        <world/>
    </element>
</root>

How can this be validated using a Schema?

Note:

element can only contain bar when attribute="foo".

element can only contain world when attribute="hello"

解决方案

You can't do this in XML Schema 1.0. In XML Schema 1.1 you will be able to use the <xs:assert> element to do it, but I'm guessing you want something that you can use now.

You can use Schematron as a second layer of validation that will allow you to test arbitrary XPath assertions about your XML document. There's a fairly old article about embedding Schematron in XSD that you might find helpful.

You'd do something like:

<rule context="element">
  <report test="@attribute = 'foo' and *[not(self::bar)]">
    This element's attribute is 'foo' but it holds an element that isn't a bar.
  </report>
  <report test="@attribute = 'hello' and *[not(self::world)]">
    This element's attribute is 'hello' but it holds an element that isn't a world.
  </report>
</rule>

Or of course you can switch to RELAX NG, which does this in its sleep:

<element name="element">
  <choice>
    <group>
      <attribute name="attribute"><value>foo</value></attribute>
      <element name="bar"><empty /></element>
    </group>
    <group>
      <attribute name="attribute"><value>hello</value></attribute>
      <element name="world"><empty /></element>
    </group>
  </choice>
</element>

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