XSD Karışık Tür İndikatörleri

Göstergeler aracılığıyla, belgede eleman kullanımını kontrol edebiliriz.

Göstergeler

Yedi tür göstergesi var:

Sıra göstergesi:

  • Tümü
  • Seçim
  • Sıra

Oluşum göstergesi:

  • maxOccurs
  • minOccurs

Grup göstergesi:

  • Grup adı
  • attributeGroup name

Order 指示器

Order 指示器用于定义元素的顺序。

All 指示器

<all> 指示器规定子元素可以按照任意顺序出现，且每个子元素必须只出现一次：

<xs:element name="person">
  <xs:complexType>
    <xs:all>
      <xs:element name="firstname" type="xs:string"/>
      <xs:element name="lastname" type="xs:string"/>
    </xs:all>
  </xs:complexType>
</xs:element>

注释：当使用 <all> 指示器时，你可以把 <minOccurs> 设置为 0 或者 1，而只能把 <maxOccurs> 指示器设置为 1（稍后将讲解 <minOccurs> 以及 <maxOccurs>）。

Choice 指示器

<choice> 指示器规定可出现某个子元素或者可出现另外一个子元素（非此即彼）：

<xs:element name="person">
  <xs:complexType>
    <xs:choice>
      <xs:element name="employee" type="employee"/>
      <xs:element name="member" type="member"/>
    </xs:choice>
  </xs:complexType>
</xs:element>

提示：如需设置子元素出现任意次数，可将 <maxOccurs> （稍后会讲解）设置为 unbounded（无限次）。

Sequence 指示器

<sequence> 规定子元素必须按照特定的顺序出现：

<xs:element name="person">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="firstname" type="xs:string"/>
      <xs:element name="lastname" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

Occurrence 指示器

Occurrence 指示器用于定义某个元素出现的频率。

注释：对于所有的 "Order" 和 "Group" 指示器（any、all、choice、sequence、group name 以及 group reference），其中的 maxOccurs 以及 minOccurs 的默认值均为 1。

maxOccurs 指示器

<maxOccurs> 指示器可规定某个元素可出现的最大次数：

<xs:element name="person">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="full_name" type="xs:string"/>
      <xs:element name="child_name" type="xs:string"> maxOccurs="10"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

上面的例子表明，子元素 "child_name" 可在 "person" 元素中最少出现一次（其中 minOccurs 的默认值是 1），最多出现 10 次。

minOccurs 指示器

<minOccurs> 指示器可规定某个元素能够出现的最小次数：

<xs:element name="person">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="full_name" type="xs:string"/>
      <xs:element name="child_name" type="xs:string">
      maxOccurs="10" minOccurs="0"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

上面的例子表明，子元素 "child_name" 可在 "person" 元素中出现最少 0 次，最多出现 10 次。

提示：Bir elemanın出现次数不受限制，请使用 maxOccurs="unbounded" 这个声明：

Bir gerçek örnek:

Adı "Myfamily.xml" olan XML dosyası:

<?xml version="1.0" encoding="ISO-8859-1"?>
<persons xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="family.xsd">
<person>
<full_name>Tony Smith</full_name>
<child_name>Cecilie</child_name>
</person>
<person>
<full_name>David Smith</full_name>
<child_name>Jogn</child_name>
<child_name>mike</child_name>
<child_name>kyle</child_name>
<child_name>mary</child_name>
</person>
<person>
<full_name>Michael Smith</full_name>
</person>
</persons>

Yukarıdaki bu XML dosyası, "persons" adında bir kök eleman içerir. Bu kök elemanın içeriğinde, üç "person" elemanı tanımladık. Her "person" elemanı, bir "full_name" elemanına sahip olmalıdır ve en fazla 5 tane "child_name" elemanına sahip olabilir.

Bu schema dosyası "family.xsd":

<?xml version="1.0" encoding="ISO-8859-1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">
<xs:element name="persons">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="person" maxOccurs="unbounded">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="full_name" type="xs:string"/>
            <xs:element name="child_name" type="xs:string">
            minOccurs="0" maxOccurs="5"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

Group gösterge

Group gösterge, ilgili numune elemanlarını tanımlamak için kullanılır.

Element grubu

Element grubu, group bildirimi ile tanımlanır:

<xs:group name="组名称">
  ...
</xs:group>

Group bildirimi içine bir all, choice veya sequence elementi tanımlamak zorundasınız. Aşağıdaki örnek, "persongroup" adlı bir group tanımlar, bu group, elementlerin kesin sırayla出现出现的一组元素i tanımlar:

<xs:group name="persongroup">
  <xs:sequence>
    <xs:element name="firstname" type="xs:string"/>
    <xs:element name="lastname" type="xs:string"/>
    <xs:element name="birthday" type="xs:date"/>
  </xs:sequence>
</xs:group>

Group tanımlamasını tamamladıktan sonra, onu diğer bir tanımlamada bu şekilde kullanabilirsiniz:

<xs:group name="persongroup">
  <xs:sequence>
    <xs:element name="firstname" type="xs:string"/>
    <xs:element name="lastname" type="xs:string"/>
    <xs:element name="birthday" type="xs:date"/>
  </xs:sequence>
</xs:group>
<xs:element name="person" type="personinfo"/>
<xs:complexType name="personinfo">
  <xs:sequence>
    <xs:group ref="persongroup"/>
    <xs:element name="country" type="xs:string"/>
  </xs:sequence>
</xs:complexType>

Özellik grubu

Özellik grubu, attributeGroup bildirimi ile tanımlanır:

<xs:attributeGroup name="组名称">
  ...
</xs:attributeGroup>

Aşağıdaki örnek, "personattrgroup" adlı bir özellik grubunu tanımlayan bir örnektir:

<xs:attributeGroup name="personattrgroup">
  <xs:attribute name="firstname" type="xs:string"/>
  <xs:attribute name="lastname" type="xs:string"/>
  <xs:attribute name="birthday" type="xs:date"/>
</xs:attributeGroup>

Özellik grubunu tanımladıktan sonra, onu diğer bir tanımlamada bu şekilde kullanabilirsiniz:

<xs:attributeGroup name="personattrgroup">
  <xs:attribute name="firstname" type="xs:string"/>
  <xs:attribute name="lastname" type="xs:string"/>
  <xs:attribute name="birthday" type="xs:date"/>
</xs:attributeGroup>
<xs:element name="person">
  <xs:complexType>
    <xs:attributeGroup ref="personattrgroup"/>
  </xs:complexType>
</xs:element>