XML XSD中为不同id枚举值配置专属内容限制的问题

我从以下XML生成了XSD文件：

<Edits>
    <Item id="AlignmentLargerThanSize">0.0</Item>
    <Item id="Machine">PI-8200</Item>
    <Item id="PackagePCBNames">Deepest level</Item>
    <Item id="ManualExactOutlineStroke">10.0</Item>
    <Item id="AlignmentPoint1Y">0.0</Item>
    <Item id="PolarityComboBox">Positive</Item>
    <Item id="AlignmentLessThanSize">10.0</Item>
</Edits>

生成的XSD如下：

<xs:element name="Item">
    <xs:complexType>
        <xs:simpleContent>
            <xs:extension base="ST_Item">
                <xs:attribute name="id" use="required">
                    <xs:simpleType>
                        <xs:restriction base="xs:string">
                            <xs:enumeration value="AlignmentLargerThanSize"/>
                            <xs:enumeration value="Machine"/>
                            <xs:enumeration value="PackagePCBNames"/>
                            <xs:enumeration value="ManualExactOutlineStroke"/>
                            <xs:enumeration value="AlignmentPoint1Y"/>
                            <xs:enumeration value="PolarityComboBox"/>
                            <xs:enumeration value="AlignmentLessThanSize"/>
                        </xs:restriction>
                    </xs:simpleType>
                </xs:attribute>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>
</xs:element>
<xs:simpleType name="ST_Item">
    <xs:restriction base="xs:string">
        <xs:enumeration value=""/>
        <xs:enumeration value="0"/>
    </xs:restriction>
</xs:simpleType>

但这个生成结果不符合需求，我需要为每个id枚举值配置专属的内容限制，示例如下：

<xs:simpleType name="Item1" id="AlignmentLessThanSize">
    <xs:restriction base="xs:decimal">
        <xs:minInclusive value="0"/>
    </xs:restriction>
</xs:simpleType>
<xs:simpleType name="Item2" id="AlignmentLargerThanSize">
    <xs:restriction base="xs:decimal">
        <xs:minExclusive value="0"/>
    </xs:restriction>
</xs:simpleType>

请问如何实现这种为不同id枚举值绑定专属内容限制的XSD配置？

要实现基于id属性值约束元素内容的需求，得靠XSD 1.1的特性——XSD 1.0不支持这种条件化的类型绑定。下面提供两种可行的实现方式：

方式一：条件类型赋值（清晰易维护） #

给每个id对应的Item定义专属简单类型，通过条件匹配自动绑定对应的内容约束：

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning"
           vc:minVersion="1.1">

    <!-- 为每个id定义专属内容约束类型 -->
    <xs:simpleType name="AlignmentLessThanSizeType">
        <xs:restriction base="xs:decimal">
            <xs:minInclusive value="0"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="AlignmentLargerThanSizeType">
        <xs:restriction base="xs:decimal">
            <xs:minExclusive value="0"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="MachineType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="PI-8200"/>
            <xs:enumeration value="PI-8300"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="PackagePCBNamesType">
        <xs:restriction base="xs:string">
            <xs:minLength value="1"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="AlignmentPoint1YType">
        <xs:restriction base="xs:decimal">
            <xs:minInclusive value="-100"/>
            <xs:maxInclusive value="100"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="PolarityComboBoxType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="Positive"/>
            <xs:enumeration value="Negative"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="ManualExactOutlineStrokeType">
        <xs:restriction base="xs:decimal">
            <xs:minInclusive value="1"/>
            <xs:maxInclusive value="20"/>
        </xs:restriction>
    </xs:simpleType>

    <!-- 定义Item元素，根据id匹配对应类型 -->
    <xs:element name="Item">
        <xs:alternative test="@id = 'AlignmentLessThanSize'" type="AlignmentLessThanSizeType"/>
        <xs:alternative test="@id = 'AlignmentLargerThanSize'" type="AlignmentLargerThanSizeType"/>
        <xs:alternative test="@id = 'Machine'" type="MachineType"/>
        <xs:alternative test="@id = 'PackagePCBNames'" type="PackagePCBNamesType"/>
        <xs:alternative test="@id = 'AlignmentPoint1Y'" type="AlignmentPoint1YType"/>
        <xs:alternative test="@id = 'PolarityComboBox'" type="PolarityComboBoxType"/>
        <xs:alternative test="@id = 'ManualExactOutlineStroke'" type="ManualExactOutlineStrokeType"/>
        <!-- 默认匹配错误，确保id必须在枚举范围内 -->
        <xs:alternative type="xs:error"/>
    </xs:element>

    <!-- 定义外层Edits容器 -->
    <xs:element name="Edits">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="Item" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

方式二：断言（紧凑灵活） #

如果不想单独定义类型，也可以在Item的复杂类型中通过xs:assert直接添加条件校验：

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning"
           vc:minVersion="1.1">

    <xs:element name="Edits">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="Item" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:element name="Item">
        <xs:complexType>
            <xs:simpleContent>
                <xs:extension base="xs:string">
                    <xs:attribute name="id" use="required">
                        <xs:simpleType>
                            <xs:restriction base="xs:string">
                                <xs:enumeration value="AlignmentLargerThanSize"/>
                                <xs:enumeration value="Machine"/>
                                <xs:enumeration value="PackagePCBNames"/>
                                <xs:enumeration value="ManualExactOutlineStroke"/>
                                <xs:enumeration value="AlignmentPoint1Y"/>
                                <xs:enumeration value="PolarityComboBox"/>
                                <xs:enumeration value="AlignmentLessThanSize"/>
                            </xs:restriction>
                        </xs:simpleType>
                    </xs:attribute>
                </xs:extension>
            </xs:simpleContent>
            <!-- 断言：根据id校验内容合法性 -->
            <xs:assert test="
                (@id = 'AlignmentLessThanSize' and . castable as xs:decimal and xs:decimal(.) >= 0) or
                (@id = 'AlignmentLargerThanSize' and . castable as xs:decimal and xs:decimal(.) > 0) or
                (@id = 'Machine' and . castable as xs:string and (. = 'PI-8200' or . = 'PI-8300')) or
                (@id = 'PackagePCBNames' and . castable as xs:string and string-length(.) > 0) or
                (@id = 'AlignmentPoint1Y' and . castable as xs:decimal and xs:decimal(.) >= -100 and xs:decimal(.) <= 100) or
                (@id = 'PolarityComboBox' and . castable as xs:string and (. = 'Positive' or . = 'Negative')) or
                (@id = 'ManualExactOutlineStroke' and . castable as xs:decimal and xs:decimal(.) >=1 and xs:decimal(.) <=20)
            "/>
        </xs:complexType>
    </xs:element>
</xs:schema>

注意事项 #

• 两种方式都需要支持XSD 1.1的解析器（比如Saxon 9.5+、Xerces 2.12+），XSD 1.0解析器无法识别这些特性。
• 条件类型赋值方式更清晰，类型可复用；断言方式更紧凑，适合简单约束场景。

内容的提问来源于stack exchange，提问作者witny