WSO2 ESB property incorrect scope - properties

Question

I have next sequence:
<payloadFactory>
<format>
<cb:accounts/>
</format>
<args/>
</payloadFactory>
<property name="accounts" type="OM" expression="//cb:accounts" />
...
<iterate id="accountIterator" continueParent="true" sequential="true" expression="//cb:accounts/cb:accountId">
<target>
<sequence>
...
<property name="accounts" type="OM" expression="//*" />
</sequence>
</target>
</iterate>
<aggregate id="accountIterator">
<onComplete expression="$body/child::*[fn:position()=1]">
<log level="custom" />
</onComplete>
</aggregate>
<enrich>
<source type="custom" xpath="get-property('accounts')"/>
<target type="body" />
</enrich>
Why property named "accounts" which was set inside "iterate" mediator has null value outside "iterate" mediator ?
Thanks

Answer 1

The flow inside the iterator runs on a separate thread and it is not visible out side. Therefore you can't access a property which is set inside the iterator mediator, outside but vice versa is possible.

Answer 2

Before calling each iteration cycle message context will be cloned and it will only be available in the context inside iterator target. Hence, by default can not get the things doing in synapse/default scope outside the iterator. If you want to store something global, use property with operation scope.
Before iterator assign your property to operation scope
Inside iterator - do modifications
Outside the iterator - assign your property to default scope (if you want to take it back to default scope)
use below structure for example:
<!--assign your property to operation scope-->
<property name="ITERATOR_DATA_PAYLOAD"
expression="get-property('DATA_PAYLOAD')"
scope="operation"
type="OM"/>
<iterate xmlns:ns="http://org.apache.synapse/xsd"
continueParent="true"
expression="//bookstore/book"
sequential="true">
<target>
<sequence>
<!--if you want to assign the property-->
<property name="DATA_PAYLOAD"
expression="get-property('operation','ITERATOR_DATA_PAYLOAD')"
type="OM"/>
</sequence>
</target>
</iterate>
<!--Outside the iterator-->
<property xmlns:ns="http://org.apache.synapse/xsd"
name="NEW_DATA_PAYLOAD"
expression="get-property('operation','ITERATOR_DATA_PAYLOAD')"
type="OM"/>