Attribute selector

Exercise

Given the following input payload:

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications
      with XML.</description>
   </book>
   <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies,
      an evil sorceress, and her own childhood to become queen
      of the world.</description>
   </book>
   <book id="bk103">
      <author>Corets, Eva</author>
      <title>Maeve Ascendant</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-11-17</publish_date>
      <description>After the collapse of a nanotechnology
      society in England, the young survivors lay the
      foundation for a new society.</description>
   </book>
</catalog>

Write a DataWeave transformation that produces the following output:

<?xml version='1.0' encoding='UTF-8'?>
<book>
  <id>bk102</id>
  <title>Midnight Rain</title>
  <author>Ralls, Kim</author>
</book>

Optional:

• Use a variable to hold the book you want and then use it in the Script.

Hints

• Note that in this case the output is XML, so there always has to be a key/tag wrapping the whole object.
• This exercise asks for the second book, but the book tags are repeated. Remember that you can use the multiple selector .* and the index selector [<n>] to get the expected value.
• To get an attribute value that lives inside a tag, you can use the attribute selector .@.

---

🔒🔓Show solution

%dw 2.0
output application/xml

var book: Object = payload.catalog.*book[1]
---
book: {
    id: book.@id,
    title: book.title,
    author: book.author
}

/* Without the variable:
book: {
    id: payload.catalog.*book[1].@id,
    title: payload.catalog.*book[1].title,
    author: payload.catalog.*book[1].author
} */