Superficially, his is a bug in XmlDumper, but it cuts a little deeper - first look I don't see that the internal representation of String values such as "null" or "true" or "false" is possible for literal constraints. (I'll open a JIRA forthwith.)<br>
<br>You have these two options as a workaround:<br><br>(1) Create a<br> global String strnull<br>and initialize it with the String "null"<br> ksession.setGlobal( "strnull", "null" );<br><br>
(2) Use<br> keyValue== ("null")<br>which Xml-dumps into a different (correct) representation.<br><br>-W<br><br><br><div class="gmail_quote">On 25 February 2011 02:32, Christina Lau <span dir="ltr"><<a href="mailto:lau.christina@hit.com.hk">lau.christina@hit.com.hk</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
Dear all,<br>
<br>
My system is transforming internal data structure to drools rule language<br>
XML file. For particular evaluation on a string field, how can I do so<br>
happen the evaluating value is one of the keywords?<br>
<br>
For example,<br>
<br>
I need to check if<br>
keyValue=="null"<br>
<br>
In rule language in XML, through the XmlDumper,<br>
<field-constraint field-name="keyValue"><br>
<literal-restriction evaluator="==" value="null" /><br>
<br>
However, this is the same for evaluation of<br>
keyValue==null //check if keyValue is null or not<br>
<br>
<br>
Would someone know how to tell the engine the different scenario in rule<br>
language XML file,<br>
evaluate on the content, and<br>
nullable of the field?<br>
<br>
Thanks a lot for your help<br>
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