XMLExtract:Reading elements and attributes with same name 2

CloverDX Platform
1

The question title is repeated cause it fits my case but it is indeed different.

I have a simple but complicated case, I am trying to fix a reader after an engine upgrade, and this has taking me a couple of days of frustration that I finally got here. This is what I’m trying to get:

I have this sample input file:


<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<feed xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.w3.org/2005/Atom" xmlns:csm="http://www.blabla.org/feed/2.0">
  <entry>
    <id>urn:nid:24477</id>
    <csm:review star_rating="3">
      <csm:themes>
        <csm:theme id="1234">A theme value</csm:theme>
      </csm:themes>
    </csm:review>
    <summary><![CDATA[This is the summary of this review]]></summary>
  </entry>
</feed>

I found that the current faulty mapping code is this:


<Mappings>
    <Mapping element="entry" outPort="1" xmlFields="id" cloverFields="csm_id_uri">
        <Mapping element="csm:theme" outPort="0" parentKey="csm_id_uri" generatedKey="csm_id_uri" xmlFields="id" cloverFields="tag_id"/>
    </Mapping>
</Mappings>

This mapping just reads nothing, all the records the log says they go to port1, but when I dump it to a file, the records are empty, no data is passed.

I think (not sure yet, but…) the expected record should have:

|urn:nid:24477|||1234||

which is:

/feed/entry/id → csm_id_uri = urn:nid:24477
/feed/entry/csm:review/csm:themes/csm:theme/@id → tag_id = 1234

and the rest of the fields are left blank.

The point is that I can’t get to have a single record with those values in a single record, I have been able to get one or the other, or two records per value.

I also tried this:


<Mapping element="entry" >

    <Mapping element="csm:review">
    <Mapping element="csm:themes">
        <Mapping element="csm:theme" outPort="1"
                 xmlFields="id;../../../id"
                 cloverFields="tag_id;csm_id_uri" />
    </Mapping>
    </Mapping>

</Mapping>

but no matter what combination I try, I can not refer to a child element using the dots, if the upper Id was an attribute instead of a child element, the problem would have been solved already. Is there a way to achieve this?

I’m looking for a general way to map N to 1 with this structure, for example, having the input


<feed>
  <entry>
    <id>5555<id>
    <listOfThings>
      <item id=33>item 1</item>
      <item id=44>item 2</item>
    </listOfThings>
  <entry>
  <entry>
    <id>6666<id>
    <listOfThings>
      <item id=77>item 3</item>
      <item id=88>item 4</item>
    </listOfThings>
  <entry>
<feed>

to get these records:


|5555|33|||
|5555|44|||
|6666|77|||
|6666|88|||

All the examples I have found are where the same name input fields are of the same nature, usually an attribute.

Can anyone please help?

Thank you in advance.

2

Hi, jfuentesve,

XMLExtract is not exactly the right component for this task. I would use XMLReader where it is possible control mapping with xpath expressions. The mapping would be as following:


<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Context xpath="//n2:theme" outPort="0" namespacePaths='n1="http://www.w3.org/2005/Atom";n2="http://www.blabla.org/feed/2.0"'>
	<Mapping cloverField="field1" xpath="../../../n1:id"/>
	<Mapping cloverField="field4" xpath="@id"/>
</Context>

This way you can process files with many entries or with many themes or both.

Best regards,

3

Hi, thank you for your response.

Unfortunately I can not find such a reader of type XMLReader available, these are the ones I can choose from:

XMLExtract
XMLXPathReader

I went ahead and implemented a solution using XMLXpathReader, but now Im dealing with a missing class that should be accesible from the plugins:


Error loading graph:/opt/ds/jetty-cloverServer/sandboxes/csm/graph/tag-association-program.grf Can't create object of type XML_XPATH_READER with reason: net/sf/saxon/sxpath/XPathEvaluator

I can run it locally from Eclipse and it works with a java test, but doesn’t work once deployed in the server, anyways that is not related to the topic. (though some help is welcome)

This is what I’m using with XMLXpathReader:

Tha mapping:


<Context xpath="/feed/entry" outPort="0" sequenceField="IndexKey" namespacePaths='"http://www.w3.org/2005/Atom";csm="http://www.blahblah.org/feed/2.0"'>
   <Mapping xpath="./id" cloverField="csm_id_uri"/>
   <Context xpath="./csm:review/csm:themes/csm:theme" parentKey="IndexKey" generatedKey="ThemeIndexKey" outPort="1">
    <Mapping xpath="./@id" cloverField="tag_id"/>
   </Context>
</Context>

The node usage:

Screen shot 2013-01-29 at 11.07.03 AM.png

The corresponding edges have these fields:

csm_id_uri;IndexKey
tag_id;ThemeIndexKey

I had to invert the order of the ports from/to the reader and the hash join to choose the right master key, using the keys in the mapping for the matching, it works like a charm.

We are using clover 3.2.1. engine and designer.