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