Question

我不知道我的问题是否被正确询问。我有一个包含DTD的XML文档。我已经定义了ATTLIST并且我想限制或修改XML验证将导致错误或将失败的DTD，如果我多次使用相同的属性。我的XML文档如下所示：

<?xml version="1.0" encoding="utf-8"?>
<!-- DTD START -->
<!DOCTYPE dtype
[
    <!ELEMENT   dtype   (ea?, eb?, ec, ed?) >
    <!ELEMENT   ea      (data+)             >
    <!ELEMENT   eb      (ee+)               >
    <!ELEMENT   ec      (data+)             >
    <!ELEMENT   ed      (data+)             >
    <!ELEMENT   ee      (data+)             >
    <!ELEMENT   data    (#PCDATA)           >

    <!ATTLIST   ee
                    ef      CDATA   #REQUIRED
    >
    <!ATTLIST   data
                    element CDATA   #REQUIRED
                    value   CDATA   #IMPLIED
                    unit    CDATA   #IMPLIED
                    min     CDATA   #IMPLIED
                    max     CDATA   #IMPLIED
                    avg     CDATA   #IMPLIED
    >
]>
<!-- DTD END -->

<!-- DATA START -->
<dtype>
  <ec>
    <data element="A" unit="counts" min="0.6621" avg="0.6819" max="0.7089" />
    <data element="B" unit="counts" min="0.0463" avg="0.0473" max="0.0503" />
    <data element="C" unit="counts" min="0.1238" avg="0.1264" max="0.1344" />
  </ec>
</dtype>
<!-- DATA END -->

<!-- should be detected as not ok ! -->
<!--
<dtype>
  <ec>
    <data element="A" unit="counts" min="0.6621" avg="0.6819" max="0.7089" />
    <data element="B" unit="counts" min="0.0463" avg="0.0473" max="0.0503" />
    <data element="B" unit="counts" min="0.1238" avg="0.1264" max="0.1344" />
    <data element="C" unit="counts" min="0.1348" avg="0.1644" max="0.1654" />
  </ec>
</dtype>
-->

我想将DTD限制为允许一个属性element="B"，例如。

这可能吗？

Answer 1

我认为DTD中唯一的选择是创建属性类型ID。 ID必须是Name（http://www.w3.org/TR/REC-xml/#NT-Name），因此这可能对您的数据无效。（虽然它适用于样本数据中的element属性。）

例如，此XML无效，因为element="A"被使用了两次：

<!DOCTYPE dtype
[
    <!ELEMENT   dtype   (ea?, eb?, ec, ed?) >
    <!ELEMENT   ea      (data+)             >
    <!ELEMENT   eb      (ee+)               >
    <!ELEMENT   ec      (data+)             >
    <!ELEMENT   ed      (data+)             >
    <!ELEMENT   ee      (data+)             >
    <!ELEMENT   data    (#PCDATA)           >

    <!ATTLIST   ee
                    ef      CDATA   #REQUIRED
    >
    <!ATTLIST   data
                    element ID   #REQUIRED
                    value   CDATA   #IMPLIED
                    unit    CDATA   #IMPLIED
                    min     CDATA   #IMPLIED
                    max     CDATA   #IMPLIED
                    avg     CDATA   #IMPLIED
    >
]>
<!-- DTD END -->

<!-- DATA START -->
<dtype>
    <ec>
        <data element="A" unit="counts" min="0.6621" avg="0.6819" max="0.7089" />
        <data element="B" unit="counts" min="0.0463" avg="0.0473" max="0.0503" />
        <data element="A" unit="counts" min="0.1238" avg="0.1264" max="0.1344" />
    </ec>
</dtype>

我可以修改/限制XML DTD的ATTLIST以允许UNIQUE属性吗？

1 个答案: