[XMLBEANS-339] Wrong handling for IdentityConstraint for key <selector xpath=".">

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Version 2.3
• Component/s: XmlObject
• Environment: Windows2000 on PC.
• Assignee: Unassigned
• Reporter: jackychang
• Created: 20/Jul/07 01:02
• Updated: 20/Jul/07 01:02

Description

This problem existed in 2.2.0 and 2.3.0. When I create a key and keyref in schema like
<xsd:element name="root">
<xsd:complexType>
<xsd:sequence minOccurs="1" maxOccurs="1">
<xsd:element name="AAA" type="myAAA"/>
<xsd:element name="BBB" type="myBBB"/>
<xsd:element name="CCC" type="xsd:string"/>
</xsd:sequence>
<xsd:attribute name="id" type="xsd:string" use="required"/>
</xsd:complexType>
<xsd:keyref name="myIdref" refer="myId">
<xsd:selector xpath="."/>
<xsd:field xpath="@id"/>
</xsd:keyref>
<xsd:key name="myId">
<xsd:selector xpath="."/>
<xsd:field xpath="CCC"/>
</xsd:key>
</xsd:element>

<xsd:complexType name="myAAA">
<xsd:sequence minOccurs="1">
<xsd:element name="a" minOccurs="1" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="DDD" type="xsd:string"/>
</xsd:sequence>
<xsd:attribute name="id" type="xsd:NCName" use="required"/>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>

<xsd:complexType name="myBBB">
<xsd:sequence minOccurs="1">
<xsd:element name="b" minOccurs="1" maxOccurs="unbounded">
<xsd:complexType>
<xsd:attribute name="idref" type="xsd:NCName" use="required"/>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
</xsd:schema>

The Xmlbeans validator will throw an exception said like "keyref can't find the key value".

But if I use the following key and keyref definition,
<xsd:keyref name="myIdref" refer="myId">
<xsd:selector xpath="./CCC"/>
<xsd:field xpath="."/>
</xsd:keyref>
<xsd:key name="myId">
<xsd:selector xpath="."/>
<xsd:field xpath="@id"/>
</xsd:key>

Everything works well. Being curious what happen in code, I open the code and debug it. What I found is "IdentityConstraint.java" wrongly handle the keyrefstat 'remove'. IdentityConstraint build a chain of selectorstate, fieldstat and keyrefstate. But when handling 'addKeyValues' in keyrefstat remove method, the selector has no any value at all in above first case. I can't explain why the selector can't be assigned with correct field value, but it happened as it. Therefore I think you must take care of it. The following code piece is my modification for remove method in keyrefstate.

void remove(Event e) {
// First check if there are any keys at the same stack level as this
// that may contribute key values to me
+ Set _myvalues = new LinkedHashSet(); // define a values for addKeyValues to keyref
for (ConstraintState cs = _next ; cs != null && cs != _elementStack._savePoint ; cs = cs._next)
{
if (cs instanceof SelectorState)
{
SelectorState sel = (SelectorState)cs;
if (sel._constraint == _constraint.getReferencedKey()) {
+ if (!sel._values.isEmpty()) // if the selector has no value, I must use its field value instead.
addKeyValues(sel._values, false);
+ else { // sometimes selector has no values, but field does have!
+ for (ConstraintState cs2 = _next; cs2 !=null && cs2 != _elementStack._savePoint ; cs2 = cs2._next) {
+ if (cs2 instanceof FieldState) { // I will find the fieldstate. If this fieldstate belongs to above selector, I will try to put the value to keyValues.
+ FieldState fie = (FieldState)cs2;
+ if (fie._selector == sel)

{ + _myvalues.add(fie._value); + }

+ }
+ }
+ }
}
}
}
+ addKeyValues(_myvalues, false);

I'm sure if this solution is OK for your project. But it seems solve my problem completely. I hope you can fix this bug as soon as possible.

/zhi