[rules-users] xdrl, null and nested properties
Hi.
I'm using Drools 5.1.0 along with .xdrl files. Now I have the problem
with the following sippet:
--cut here--
<dro:and-conditional-element>
<dro:pattern object-type="TaskResults">
<dro:field-constraint field-name="lastResult">
<dro:literal-restriction evaluator="!="
value="null"/>
</dro:field-constraint>
<dro:field-constraint
field-name="lastResult.returnValues["ReturnKey"]">
<dro:literal-restriction evaluator="=="
value="returnvalue"/>
</dro:field-constraint>
</dro:pattern>
</dro:and-conditional-element>
--cut here--
It compiles just fine, but when executed it fails with:
Caused by: org.drools.RuntimeDroolsException: Exception executing
predicate lastResult.returnValues["ReturnKey"] == "returnvalue"
Caused by: [Error: unable to access property (null parent): returnValues]
[Near : {... Unknown ....}]
^
[Line: 1, Column: 0]
at
org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:886)
It seems that the second field constraint is also evaluated, although
the first should already return "false". Are there no short-circuits
within pattern constraints? How would I express that best in xdrl
conform manner? Use eval?
Thanks
Veit