XML DTDを使用して要素内の特定の入力のみを許可する

Question

申し訳ありませんが、次の入力（エレクトロニクス、食料雑貨品、家庭用）のみをカテゴリ要素に許可しようとしていますが、これを行う。私は内部DTDを使用しており、どのように文書を処理するのかという2つの完全な例を持っています。

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE manufacturer[ 
    <!ELEMENT manufacturer (companyName, address, phone, contactPerson?, products)> 
    <!ATTLIST manufacturer identifier CDATA #REQUIRED> 
    <!ELEMENT companyName (#PCDATA)> 
    <!ELEMENT address (#PCDATA)> 
    <!ELEMENT phone (#PCDATA)> 
    <!ELEMENT contactPerson (#PCDATA)> 
    <!ELEMENT products (product+)> 
    <!ELEMENT product (model, price, description, category)> 
    <!ATTLIST product code CDATA #REQUIRED> 
    <!ELEMENT model (#PCDATA)> 
    <!ELEMENT price (#PCDATA)> 
    <!ELEMENT description (#PCDATA)> 
    <!ELEMENT category (household|groceries|electronics) 
    ]> 

<manufacturer identifier = "m1"> 
    <companyName>Kitchen Manufacturers International</companyName> 
    <address>1256 Factory Lane, Cleveland, OH 44111</address> 
    <phone>216-333-4444</phone> 
    <contactPerson>Fred Smith</contactPerson> 
    <products> 
     <product code = "X345"> 
      <model>Sun Beam Mixer</model> 
      <price>14.75</price> 
      <description>Popular handheld mixer</description> 
      <category>household</category> 
     </product> 
     <product code = "MW30"> 
      <model>GE30 Microwave</model> 
      <price>99.95</price> 
      <description>A popular model</description> 
      <category>household</category> 
     </product> 
    </products> 
</manufacturer> 

<manufacturer identifier = "m3"> 
    <companyName>Kraft Foods Incorporated</companyName> 
    <address>1515 Kraft Avenue, Chicago, IL 37897</address> 
    <phone>222-333-4444</phone> 
    <products> 
     <product code = "345DR"> 
      <model>Jiffy Peanut Butter</model> 
      <price>4.95</price> 
      <description>America’s favorite, made from real peanuts</description> 
      <category>groceries</category> 
     </product> 
     <product code = "321SD"> 
      <model>Mac N' Cheese</model> 
      <price>1.99</price> 
      <description>Every child’s favorite dinner</description> 
      <category>groceries</category> 
     </product> 
     <product code = "123DD"> 
      <model>Rice Krispies</model> 
      <price>2.99</price> 
      <description>Snap Crackle and Pop</description> 
      <category>groceries</category> 
     </product> 
    </products> 
</manufacturer> 

Answer 1

DTDでXML要素の内容に制限を指定することはできません。あなたが指定したのはcategoryの子要素はhousehold ...などです。