使用表单生成器对示例动态下拉列表示例的变体，如何将下拉列表引用到另一个字段的值。我可以进行调试＆＃39;使用../pet更改文本字段，但项目[@ group = context（）/../ pet]未按预期工作。
注意：＆＃39; petnames＆＃39;包含模型，但我无法在内部引用它，因此我引用了相同格式的外部XML文件。
<xh:html xmlns:xh="http://www.w3.org/1999/xhtml"
xmlns:xxi="http://orbeon.org/oxf/xml/xinclude"
xmlns:ev="http://www.w3.org/2001/xml-events"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:saxon="http://saxon.sf.net/"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:fb="http://orbeon.org/oxf/xml/form-builder"
xmlns:xxf="http://orbeon.org/oxf/xml/xforms"
xmlns:sql="http://orbeon.org/oxf/xml/sql"
xmlns:fr="http://orbeon.org/oxf/xml/form-runner"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xf="http://www.w3.org/2002/xforms"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:exf="http://www.exforms.org/exf/1-0"
fr:data-format-version="4.0.0">
<xh:head>
<xh:title>Example Dynamic data dropdown</xh:title>
<xf:model id="fr-form-model" xxf:expose-xpath-types="true">
<!-- Main instance -->
<xf:instance id="fr-form-instance" xxf:exclude-result-prefixes="#all" xxf:index="id">
<form>
<section-1>
<pet/>
<control-4/>
<mypetname itemset-empty="true"/>
</section-1>
</form>
</xf:instance>
<xf:instance id="petnames">
<root>
<item group="cat" value="Kitty"/>
<item group="cat" value="Garfield"/>
<item group="dog" value="Spot"/>
<item group="dog" value="Rover"/>
<item group="fish" value="Bubbles"/>
<item group="fish" value="Bob"/>
<item group="cobra" value="King"/>
<item group="cobra" value="Shelby"/>
</root>
</xf:instance>
<!-- Bindings -->
<xf:bind id="fr-form-binds" ref="instance('fr-form-instance')">
<xf:bind id="section-1-bind" name="section-1" ref="section-1">
<xf:bind id="pet-bind" ref="pet" name="pet"/>
<xf:bind id="mypetname-bind" ref="mypetname" name="mypetname"/>
<xf:bind id="control-4-bind" ref="control-4" name="control-4" xxf:whitespace="trim"
calculate="../pet"/>
</xf:bind>
</xf:bind>
<!-- Metadata -->
<xf:instance xxf:readonly="true" id="fr-form-metadata" xxf:exclude-result-prefixes="#all">
<metadata>
<application-name>samples</application-name>
<form-name>DynamicDataDropdown</form-name>
<title xml:lang="en">Example Dynamic data dropdown</title>
<description xml:lang="en"/>
</metadata>
</xf:instance>
<!-- Attachments -->
<xf:instance id="fr-form-attachments" xxf:exclude-result-prefixes="#all">
<attachments>
<css mediatype="text/css" filename="" size=""/>
<pdf mediatype="application/pdf" filename="" size=""/>
</attachments>
</xf:instance>
<!-- All form resources -->
<xf:instance xxf:readonly="true" id="fr-form-resources" xxf:exclude-result-prefixes="#all">
<resources>
<resource xml:lang="en">
<pet>
<label>Pick a pet</label>
<hint/>
<item>
<label>Cat</label>
<value>cat</value>
</item>
<item>
<label>Dog</label>
<value>dog</value>
</item>
<item>
<label>Fish</label>
<value>fish</value>
</item>
<item>
<label>Cobra</label>
<value>cobra</value>
</item>
</pet>
<control-4>
<label>debug</label>
<hint/>
</control-4>
<mypetname>
<label>Your pet names</label>
<hint/>
</mypetname>
<section-1>
<label>Untitled Section</label>
</section-1>
</resource>
</resources>
</xf:instance>
</xf:model>
</xh:head>
<xh:body>
<fr:view>
<fr:body xmlns:p="http://www.orbeon.com/oxf/pipeline" xmlns:xbl="http://www.w3.org/ns/xbl"
xmlns:oxf="http://www.orbeon.com/oxf/processors">
<fr:section id="section-1-control" bind="section-1-bind">
<xf:label ref="$form-resources/section-1/label"/>
<fr:grid>
<xh:tr>
<xh:td>
<xf:select1 id="pet-control" bind="pet-bind" appearance="dropdown">
<xf:label ref="$form-resources/pet/label"/>
<xf:hint ref="$form-resources/pet/hint"/>
<xf:alert ref="$fr-resources/detail/labels/alert"/>
<xf:itemset ref="$form-resources/pet/item">
<xf:label ref="label"/>
<xf:value ref="value"/>
</xf:itemset>
</xf:select1>
</xh:td>
<xh:td>
<xf:input id="control-4-control" bind="control-4-bind">
<xf:label ref="$form-resources/control-4/label"/>
<xf:hint ref="$form-resources/control-4/hint"/>
<xf:alert ref="$fr-resources/detail/labels/alert"/>
</xf:input>
</xh:td>
<xh:td>
<fr:databound-select1 xmlns="http://orbeon.org/oxf/xml/form-builder"
xmlns:xxbl="http://orbeon.org/oxf/xml/xbl"
id="mypetname-control"
resource="http://192.168.0.80/petnames.xml"
bind="mypetname-bind">
<xf:label ref="$form-resources/mypetname/label"/>
<xf:hint ref="$form-resources/mypetname/hint"/>
<xf:alert ref="$fr-resources/detail/labels/alert"/>
<xf:itemset ref="/root/item[@group=context()/../pet]">
<xf:label ref="@value"/>
<xf:value ref="@value"/>
</xf:itemset>
</fr:databound-select1>
</xh:td>
</xh:tr>
</fr:grid>
</fr:section>
</fr:body>
</fr:view>
</xh:body>
</xh:html>
答案 0 :(得分：0)
您可以使用以下内容：
<xf:itemset ref="/root/item[@group = xxf:instance('fr-form-instance')/section-1/pet]">
在这种情况下，context()将无效，因为ref中的XPath表达式是在XBL组件内部进行评估的，并且无法访问组件外部的内容。但是，在某些情况下，打破封装很有用，对于这些情况，扩展函数xxf:instance()允许您这样做。