How To Slow Cook A Piglet

This is how the pieces are glued together:

1. Consider the original XML data:
   

   <Order>
     <Number>01234</Number>
     <Status>OPEN</Status>
   </Order>

2. The XML data is translated into Perl data structure, utilizing XML::SAX(why?):

   $VAR1 = {
     'Order' => {
       'Status' => 'OPEN',
       'Number' => '01234'
     }
   };

   The unordered hash index will not mangle the report anymore since:


3. Along the way (of parsing XML data using XML::SAX), a report template is created with references at the right places.
   
   

   	Status	Notes
   <Order>
   <Number>01234</Number>	${$REPORT[0]}{'RESULT'}	${$REPORT[0]}{'NOTES'}
   <Status>OPEN</Status>	${$REPORT[1]}{'RESULT'}	${$REPORT[1]}{'NOTES'}
   </Order>



4. To the bridge the result of comparison and the report template, another data structure is created (will be called: bridge) and it has an exact hash structure as the XML data, but it is holding references to the report template.

   $BRIDGE1 = {
     'Order' => {
       'Status' => '$REPORT[1]',
       'Number' => '$REPORT[0]'
     }
   };

5. Consider the check data for the XML data above:
   

   <Order>
     <Number><SQL>'SELECT Status FROM Order WHERE ORDER_ID = <value>'</SQL></Number>
     <Status><SQL>'SELECT OrdNum FROM Order WHERE ORDER_ID = <value>'</SQL></Status>
   </Order>

   Readability is the main reason the check/validation is written in XML format.


6. Converted to Perl data structure using XML::Simple

   $CHECK1 = {
     'Order' => {
       'Status' => { SQL => 'SELECT Status FROM Order WHERE ORDER_ID = <value>'},
       'Number' => { SQL => 'SELECT OrdNum FROM Order WHERE ORDER_ID = <value>'},
     }
   };

7. Iterating through the XML hash structure, while maintaining same path of traversal with the bridge and check hash structure:
   

   $XML{'Order'} 
     -> $BRIDGE1{'Order'} 
       -> $CHECK1{'Order'}
   
   $XML{'Order'}{'Status'} 
     -> $BRIDGE1{'Order'}{'Status'} 
       -> $CHECK1{'Order'}{'Status'}

8. Find the end of XML hash structure branch to extract the value.
   

   if (ref($XML{'Order'}{'Status'}) eq "") {
     $XMLValue = $XML{'Order'}{'Status'};
   }

9. Get the SQL syntax from check hash and get the content from database.
   

   if (exists $CHECK1{'Order'}{'Status'}{'SQL'}) {
     $SQL = $CHECK1{'Order'}{'Status'}{'SQL'};
   }
   else {
     # bitch later: no SQL defined.
   }
   $DBVALUE = getValue($SQL);

10. Compare the content from XML hash structure and database and write the result out to $REPORT[$index], which provided by bridge hash.
    

    if ($XMLValue eq $DBVALUE) {
      eval "\${".$BRIDGE1{'Order'}{'Status'}."}{'RESULT'} = 'PASSED';";
      eval "\${".$BRIDGE1{'Order'}{'Status'}."}{'NOTES'}  = '$NOTE';";
    }
    else {
      eval "\${".$BRIDGE1{'Order'}{'Status'}."}{'RESULT'} = 'FAILED';";
      eval "\${".$BRIDGE1{'Order'}{'Status'}."}{'NOTES'}  = '$NOTE';";
    }

11. After traversing all of the branches of XML hash structure, open the report template and evaluate template, producing:
    
    

    	Status	Notes
    <Order>
    <Number>01234</Number>	PASSED
    <Status>OPEN</Status>	PASSED
    </Order>