If we were to start mashing up right now, between XSPF, YouTube’s XML response, and RSS, we would have to create three different parsers to handle all three response formats. We would have to comb through the documentation and create flexible parsers for all three formats. If the XML response for any of these formats changes, we would also be responsible for changing our parser code. This isn’t a difficult task, but we should be aware that someone else has already done the work for us. Someone else has already dissected the XML code. To save time, we can leverage this work for our mashup.
We used PEAR, earlier in Chapter 1 to help with XML-RPC parsing. For this project, we will once again use PEAR to save us the trouble of writing parsers for the three XML formats we will encounter.
For this project, we will take a look at three packages for our mashup. File_XSPF is a package for extracting and setting up XSPF playlists. Services_YouTube is a Web Services package that was...