Accessing ancestor values in xpath with Solr DataImportHandler - xpath

Question

If my xml is structured like so:
<fruit>
<apple appleId="apple_1">
<core coreId="core_1">
<seed>1</seed>
<seed>2</seed>
</core>
</apple>
<apple appleId="apple_2">
<core coreId="core_1">
<seed>1</seed>
</core>
</apple>
</fruit>
and I want the seeds to be the documents in my solr schema, how can I access the appleId and coreId?
Here's the pertinent entity definition from my data-config.xml:
<entity name="apples"
processor="XPathEntityProcessor"
stream="true"
forEach="/fruit/apple/core/seed"
url="fruit.xml"
transformer="script:create_id"
>
<field column="seed_s" xpath="/fruit/apple/core/seed" />
<field column="apple_id_s" xpath="/fruit/apple/#appleId" />
</entity>
script:create_id creates a unique id for each seed.
In this example, apple_id_s is coming back as null.

Answer 1

I found the problem. I need to use commonField="true" and make sure to loop through each apple and core. Also, I need to set the pk="seed_s" which triggers solr to store the document.
Here's my new entity definition:
<entity name="apples"
processor="XPathEntityProcessor"
stream="true"
pk="seed_s"
forEach="/fruit/apple/core/seed | /fruit/apple | /fruit/apple/core"
url="fruit.xml"
transformer="script:create_id"
>
<field column="seed_s" xpath="/fruit/apple/core/seed" />
<field column="apple_id_s" xpath="/fruit/apple/#appleId" commonField="true"/>
<field column="core_id_s" xpath="/fruit/apple/core/#coreId" commonField="true"/>