Procedure 7.1. Task

1. Take an XML message such as the following sample:

   <shopping>
       <category type="groceries">
           <item>Chocolate</item>
           <item>Coffee</item>
       </category>
       <category type="supplies">
           <item>Paper</item>
           <item quantity="4">Pens</item>
       </category>
           <category type="present">
           <item when="Aug 10">Kathryn's Birthday</item>
       </category>
   </shopping>
   

2. You can modify the "supplies" category in the above shopping list by adding two more "pens". To do this, write a simple Groovy script and aim it at the message's <category> elements.
3. As a result, the script simply iterates over the <item> elements in the category, and in instances where the category type is "supplies" and the item is "pens", the quantity is incremented by two:

   <?xml version="1.0"?>
   <smooks-resource-list xmlns="http://www.milyn.org/xsd/smooks-1.1.xsd" 
      xmlns:core="http://www.milyn.org/xsd/smooks/smooks-core-1.3.xsd"
      xmlns:g="http://www.milyn.org/xsd/smooks/groovy-1.1.xsd">
   
      <core:filterSettings type="SAX" />
       
      <g:groovy executeOnElement="category">
         <g:script>
         <!--
            use(DOMCategory) {
             // Modify "supplies": we need an extra 2 pens...
             if (category.'@type' == 'supplies') {
                 category.item.each { item ->
                     if (item.text() == 'Pens') {
                         item['@quantity'] = item.'@quantity'.toInteger() + 2;
                     }
                 }
             }
         }
           
         // When using the SAX filter, we need to explicitly write the fragment
         // to the result stream...
         writeFragment(category);
         -->
         </g:script>
      </g:groovy>
   
   </smooks-resource-list>