Using XPATH in jmeter - based on parent - jmeter

Question

I have a xml file having the following structure:
<subscriberDetailsItem>
<externalSubId>911</externalSubId>
<paymentIndicator>2</paymentIndicator>
<IMSI>302</IMSI>
<MSISDN>416</MSISDN>
<status>A</status>
<outSubscriptionDetails>
<subscriptionDetailsItem>
<socId>ABCDEF</socId>
<featureCode>GHIJKL</featureCode>
<startDate>20180720000000</startDate>
<featureSeq>47452111</featureSeq>
<subscriptionType>DATA</subscriptionType>
<shareGroupCd>SHARE</shareGroupCd>
<initialValueBytes>1073741824</initialValueBytes>
<priority>3000</priority>
<balanceType>BAL</balanceType>
</subscriptionDetailsItem>
</outSubscriptionDetails>
</subscriberDetailsItem>
I want to be able to extract the socID field based on the externalSubId field. Essentially, I want to be able to do this:
if externalSubId=911, then, extract SOCID. Anyone has tips?

Answer 1

You didn't specify where would you want to extract it, so I assume you can use XPath Extractor as a post-processor to some sampler that reads that file.
You configure post-processor like this:
XPath Query can be built like this:
Select subscriberDetailsItem that has externalSubId with the value you want:
//subscriberDetailsItem[externalSubId=911]
Select socId either by using absolute path:
//subscriberDetailsItem[externalSubId=911]/outSubscriptionDetails/subscriptionDetailsItem/socId
or you can omit entities in the middle if socId cannot be found elsewhere in the item:
//subscriberDetailsItem[externalSubId=911]//socId