[Xsltforms-support] Cross instance XPath evaluation

SourceForge Headquarters 225 Broadway Suite 1600 San Diego, CA 92101 +1 (858) 422-6466

Hello everybody,

Below in this message is a simplified example of form for editing a  
bug in a bug tracking system based on XForms.

The idea is having a separate instance (id=states) with the rules of  
the bug tracking system indicating which fields should be read-only,  
relevant and/or required according to the current state of the bug.

Is it possible to do this in xsltforms?  As you can see with the  
example, neither the conditions or even the xforms:output can handle  
xpath expressions like this:  
instance('states')/State[@id=instance('bug')/State]/@require-commen

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet href="xsltforms/xsltforms.xsl" type="text/xsl" ?>
<?xsltforms-options debug="yes" lang="es"  ?>
<html xmlns="http://www.w3.org/1999/xhtml"  
xmlns:xsd="http://www.w3.org/2001/XMLSchema"  
xmlns:xforms="http://www.w3.org/2002/xforms"  
xmlns:ev="http://www.w3.org/2001/xml-events">
	<head>
		<title>Conditional Relevant and Required Test</title>
		<style type="text/css">
@namespace xforms url("http://www.w3.org/2002/xforms");
body {     font-family: Helvetica;sans-serif;}
label.xforms-label { display:block;}
    </style>
		<xforms:model id="xmod">
			<xforms:instance id="bug">
				<Bug>
					<ID/>
					<Date/>
					<CurrentState>new</CurrentState>
					<Subject/>
					<Description/>
					<Comment/>
				</Bug>
			</xforms:instance>
			<xforms:instance id="states">
				<States>
					<State id="new" can-edit="true" require-comment="false"  
show-comment="false"/>
					<State id="assigned" can-edit="true" require-comment="false"  
show-comment="true"/>
					<State id="solved" can-edit="true" require-comment="true"  
show-comment="true"/>
					<State id="verified" can-edit="true" require-comment="false"  
show-comment="true"/>
					<State id="tested" can-edit="true" require-comment="false"  
show-comment="true"/>
					<State id="closed" can-edit="false" require-comment="false"  
show-comment="false"/>
				</States>
			</xforms:instance>
			<xforms:bind nodeset="/Bug/Date" type="xsd:date" required="true()"/>
			<xforms:bind nodeset="/Bug/State" type="xsd:string" required="true()"/>
			<xforms:bind nodeset="/Bug/Subject" type="xsd:string"  
readonly="not(instance('states')/State[@id=instance('bug')/State]/@can-edit)"/>
			<xforms:bind nodeset="/Bug/Description" type="xsd:string"  
readonly="not(instance('states')/State[@id=instance('bug')/State]/@can-edit)"  
/>
			<xforms:bind nodeset="/Bug/Comment" type="xsd:string"  
relevant="instance('states')/State[@id=instance('bug')/State]/@show-comment"  
required="instance('states')/State[@id=instance('bug')/State]/@require-comment"/>
		</xforms:model>
	</head>
	<body>
		<xforms:group ref="/Bug" model="xmod">
			<xforms:input ref="ID" model="xmod">
				<xforms:label>Bug ID</xforms:label>
			</xforms:input>
			<xforms:input ref="Date" model="xmod">
				<xforms:label>Bug Date</xforms:label>
			</xforms:input>
			<xforms:select1 ref="CurrentState" model="xmod">
				<xforms:label>State</xforms:label>
				<xforms:itemset model="xmod" nodeset="instance('states')/State">
					<xforms:label ref="@id"/>
					<xforms:value ref="@id"/>
				</xforms:itemset>
			</xforms:select1>
			<xforms:input ref="Subject" model="xmod">
				<xforms:label>Subject</xforms:label>
			</xforms:input>
			<xforms:textarea ref="Description" model="xmod">
				<xforms:label>Bug Description</xforms:label>
			</xforms:textarea>
			<xforms:textarea ref="Comment" model="xmod">
				<xforms:label>Comments</xforms:label>
			</xforms:textarea>
		</xforms:group>
		<xforms:group ref="" model="xmod">
			<xforms:label>Rules for this State</xforms:label>
			<xforms:output ref="instance('bug')/CurrentState" model="xmod">
				<xforms:label>Current State</xforms:label>
			</xforms:output>
			<xforms:output  
ref="instance('states')/State[@id=instance('bug')/CurrentState]/@can-edit"  
model="xmod">
				<xforms:label>Can edit Bug</xforms:label>
			</xforms:output>
			<xforms:output  
ref="instance('states')/State[@id=instance('bug')/CurrentState]/@show-comment"  
model="xmod">
				<xforms:label>Show comment field</xforms:label>
			</xforms:output>
			<xforms:output  
ref="instance('states')/State[@id=instance('bug')/CurrentState]/@require-comment"  
model="xmod">
				<xforms:label>Comment Required</xforms:label>
			</xforms:output>
		</xforms:group>
	</body>
</html>