| Processing XML with Perl |    | Michel Rodriguez | 
 ![]() Tree Processing  |     |  ![]() XML transformation Modules  |  
Filtering vs Extracting
Filtering
- Process what you want, output the rest unchanged
 - Flexible and easy to maintain when the format of the output changes
 - Similar to the Unix filter model
 
Extracting
- Extract the elements you want to process, do not output the rest
 - Better control over the output
 - Can be harder to maintain
 
Which model to choose?
- The decision can be made at each level in the XML tree
 - Depends on the rest of the processing
 
 ![]() Tree Processing  |     |  ![]() XML transformation Modules  |  
 

