AsyncProcess2 test ported to Axis2 deployment not functioning properly do to an 
error when evaluating the XPath10 expression
----------------------------------------------------------------------------------------------------------------------------

                 Key: ODE-71
                 URL: http://issues.apache.org/jira/browse/ODE-71
             Project: Apache Ode
          Issue Type: Bug
          Components: BPEL Compilation/Parsing, BPEL Runtime
    Affects Versions: Incubator
         Environment: win32_x86, windows xp, Tomcat with ode's generated axis2 
war, debugging with Eclipse dev environment
            Reporter: Dave MacLean


(Pasting post from mailing list, will attach unit test in a zip)




Following up, I think a more correct change would be to pursue what I listed as 
"a)" below:

In org.apache.ode.bpel.engine.BpelRuntimeContextImpl, under the method 
"getPartData", we currently have the code:

public Node getPartData(Element message, Part part) {
    Element partEl = DOMUtils.findChildByName(
                                        (Element) message, 
                                        new QName(null, part.name), 
                                        false);

    if (partEl == null)
        return null;

    Node container = DOMUtils.getFirstChildElement(partEl);

    if (container == null)
        container = partEl.getFirstChild(); // either a text node / element

    return container;
}

This seems incorrect.  Shouldn't part data return the actual part and not the 
part's first child?  


I would propose to change this to:

public Node getPartData(Element message, Part part) {
    return DOMUtils.findChildByName(
                                        (Element) message, 
                                        new QName(null, part.name), 
                                        false);

}


For a wsdl that contains a message like this:

        <message name="ProcessInputMessage">
                <part name="payload" element="typ:AllOrders"/>
        </message>

The dom-parsed xml structure ends up looking like:

<?xml version="1.0" encoding="UTF-8"?>
<message>
<payload>
    <AllOrders xmlns="uri:com.bptest.types">
                <Order>
                        <OrderId>1161286397524-1</OrderId>
                        <OrderType>BookOrder</OrderType>
                        <!-- etc... -->



The current version of the method getPartData method returns the "AllOrders" 
tag, the proposed version would return the "payload" tag.
Does this make sense?  With this change, the xpath evaluation works correctly, 
since when the XPath10 libaries start their evaluation of "/typ:AllOrders" on 
the first child of "payload", it matches "AllOrders"
correctly.

I guess it just makes more sense that "getPartData" would actually get the part 
instead of getting the part's first child...


Any comments on this?

Thanks,

Dave

-----Original Message-----
From: Dave MacLean [mailto:[EMAIL PROTECTED]
Sent: Thursday, October 19, 2006 12:06 PM
To: [email protected]
Subject: XPath10 expression evaluation and the AsyncProcess2 example - 
potential fix

Hello,
I've been working on getting the AsyncProcess2 example to work under an axis 2 
deployment, and I think I ran into a bug.

The xpath evaluation was failing when trying to evaluate this "from"
line of the first assign in the bpel:

<from
expressionLanguage="urn:oasis:names:tc:wsbpel:2.0:sublang:xpath1.0">
  count(bpws:getVariableData('Input', 'payload',
'/typ:AllOrders')/typ:Order)
</from>


In particular, it had trouble evaluating the /typ:AllOrders expression.
The actual xml I'm using for the soap message is the one that appears in 
subversion for the example, and starts like this:

<SOAP-ENV:Envelope
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/";>
  <SOAP-ENV:Body>
        <AllOrders xmlns="uri:com.bptest.types">
                <Order >
<!-- etc... -->


Tracing into
org.apache.ode.bpel.elang.xpath10.runtime.XPath10ExpressionRuntime, in the 
createContext method, the code instantiates a new ContextSupport with a 
BpelDocumentNavigator created using: 

new BpelDocumentNavigator(ctx.getRootNode()) 

where ctx is the EvaluationContext passed in.

The problem is the root node returned here points to the AllOrders element.  
That would appear to be ok, but when tracing into the jaxen evaluation later 
on, it starts comparisons with the *first child* of the root node given - That 
is, the order of the nodes returned by the AxisNodeIterator used in the jaxen 
source never returns the root node itself, just the children and siblings.

This leads to the first comparison being against that first "<Order>"
tag, which causes no matches to occur and an empty array resulting from the 
evaluation (when it should match that first "<AllOrders>" tag and return that 
one match.  Since I'm assuming the jaxen evaluation code is correct, it looks 
like we *need* to have some document wrapping the root node in this case *or* 
we need to have the EvaluationContext's root node returning a "parent" node of 
the node we're actually interested in...

For example, changing the createContext method to the below did fix the problem 
I was having (but I'm worried this exact change may cause other unexpected 
behavior):


private Context createContext(OXPath10Expression oxpath, EvaluationContext ctx) 
{
    JaxenContexts bpelSupport = new JaxenContexts(oxpath, _extensionFunctions, 
ctx);
    Node rootNode = ctx.getRootNode();
    if (rootNode!=null && rootNode.getParentNode()!=null)
    {
        rootNode = rootNode.getParentNode();
    }
    ContextSupport support = new ContextSupport(new 
JaxenNamespaceContextAdapter(oxpath.namespaceCtx),
                                                bpelSupport, bpelSupport, 
                                                new 
BpelDocumentNavigator(rootNode));
    Context jctx = new Context(support);

    if (ctx.getRootNode() != null)
      jctx.setNodeSet(Collections.singletonList(ctx.getRootNode()));

    return jctx;
  }


Basically, it just sets the BpelDocumentNavigator to use the parent node of the 
root node returned by the EvaluationContext, if available.  With this change 
and a proper deploy.xml file (and a few minor wsdl changes), the AsyncProcess2 
example runs and returns correctly in the Axis2 environment.


Can any one provide guidance on the "proper" way to be doing something 
equivalent? 

a) Should the EvaluationContext.getRootNode() method return a wrapping 
document/parent node?

Or,
b) Should we be doing something like I have above, where we pass in the proper 
root node when creating the navigator?

Or,
c) Should the navigator somehow be modified so that it uses the correct root 
node when calling the jaxen libraries to find matches to the expression?


I'm going to attach another thread below that might be related to this
same issue, although it's related to XPath20 and not XPath10.  


Thanks in advance,

Dave







>From "Matthieu Riou" <[EMAIL PROTECTED]> 
Subject Re: XPath 20 
Date Tue, 19 Sep 2006 17:45:38 GMT 

Ok, I've found it. Your part is a type, not an element. And the
expression
$request.requestMessageData points to the part itself, any XPath
expression
will therefore be evaluated on the nodeset of the part child nodes. So
the
full expression should be $request.requestMessageData/requestID, you
don't
need to repeat the part name in there as there's no element for it.

On 9/18/06, Lance Waterman <[EMAIL PROTECTED]> wrote:
>
>
>
> On 9/18/06, Matthieu Riou <[EMAIL PROTECTED]> wrote:
>
> > Hi Lance,
> >
> > See my comments inline...
> >
> > 1) XPath20ExpressionRuntime ( line 173 )
> > >
> > >             Object evalResult =
expr.evaluate(DOMUtils.newDocument(),
> > > type);
> > >
> > > Does this imply that all xpath syntax must contain a variable
> > reference?
> >
> >
>



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