Re: [wsbpel] Issue 11 - It's Baaaack -*-*- other XML syntax issues

[Alex Yiu <alex.yiu@oracle.com>]

Danny,

No problem. Opening a new issue is exactly what I wanted to do anyway.
It is just that I start reading some of examples:

  <assign>
    <append>
      <from variable="PO" part="PO"
query="/PurchaseOrder/LineItem[loopIndex]" />
      <to variable="LineIn"/>
    </copy>
  </assign>

I think it should be:

      <from variable="PO" part="PO"
query="/PurchaseOrder/LineItem[$loopIndex]" />

I just want to make sure the right XPath syntax is being used in BPEL and issue 11 discussion to avoid future confusion.


Thanks!



Regards,
Alex Yiu


Danny van der Rijn wrote:

alex -

i don't mean to brush this off, but issue 11 has so much hanging off of it
already.  if you want to pursue this, could you propose a new issue?

thanks
danny

----- Original Message ----- 
From: "Alex Yiu" <alex.yiu@oracle.com>
To: "Danny van der Rijn" <dannyv@tibco.com>
Cc: "'Wsbpel@Lists. Oasis-Open. Org (E-mail)'"
<wsbpel@lists.oasis-open.org>; <ALEX.YIU@oracle.com>
Sent: Monday, February 23, 2004 4:08 PM
Subject: Re: [wsbpel] Issue 11 - It's Baaaack -*-*- other XML syntax issues


  

Hi, Danny and others,

Besides digging deeper into Issue 11, we may also want to follow up 2
other (maybe orthogonal) syntax issues about referencing a variable in
XPath in BPEL.

(1)
Right now, there are three BPWS (XPath) functions defined in BPEL.

bpws:getVariableProperty ('variableName', 'propertyName')
bpws:getVariableData ('variableName', 'partName'?, 'locationPath'?)
bpws:getLinkStatus('linkName')

For refering to a variable data, if data is of an XSD complex type or
XSD simple type (not WSDL 1.1 type), do we want to add another way to
refer to a variable on top of getVariableData Function Call? That is
using "$varName" syntax.

Currently, we have:

"bpws:getVariableData(orderDetails) > 100"

The additional way:

"$orderDetails > 100"

Note that:

    * the additional syntax already exists in XPath 1.0, 2.0 and XQuery
      spec for a while. Its semantics and syntax are very stable and
      clear to existing XPath users (and future XQuery users)
    * Its advantage:
          o simple, less typing :-)
          o easier and better type checking analysis in XPath (and
            future XQuery): a variable reference can have a more
            specific type, instead of a generic getVariableData which
            essentually returns xsd:any

References:
http://www.w3.org/TR/xpath#NT-FunctionCall
http://www.w3.org/TR/xpath#NT-VariableReference


(2)
There are typo in our BPEL examples

"bpws:getVariableProperty(stockResult,level) > 100"
"bpws:getVariableProperty(stockResult,level) >= 0"
"bpws:getVariableData(orderDetails) > 100"

I guess we need to put quotations on function parameters.
It becomes:

"bpws:getVariableProperty('stockResult','level') > 100"
"bpws:getVariableProperty('stockResult','level') >= 0"
"bpws:getVariableData('orderDetails') > 100"





Do we want to open 2 issues for the above need?

Thanks for reading the email.



Regards,
Alex Yiu


[P.S.: I definitely have viewpoints on Issue 11. :-) Before I voice my
concrete opinions, I need to discuss more with other Oracle internal
folks first. Meanwhile, I will stay tune with the ongoing Issue 11
discussion. Thanks! ]