Why Convert Another Data Format to XML?

XML is everywhere.You see it online, read about it in publications , see it in the bookstore, and that's just the beginning. XML has quickly become the de facto way for applications to communicate. Although XML enjoys huge popularity, it is just now beginning to be widely implemented in applications; new standards are evolving almost weekly, and the technology still isn't even close to reaching its full potential.

Now, you might ask, how does that apply to this chapter? XML is powerful and there are numerous tools available to make it work. A majority of new applications are incorporating XML as the primary data interchange and data storage format. Given that, most applications that want to seamlessly integrate into the applications that utilize XML must adapt to the XML standard. Many legacy applications that are still deployed use either their native binary format or other widely adapted data formats to communicate. One of the most popular formats is CSV. Because CSV-formatted documents are just plain text, it is an easy format to adopt. One problem with CSV is that the data is not structured and can't be easily described, as it can with XML.

Another format that is commonly used and distributed among users on Microsoft Windows platforms is the binary Microsoft Excel format. Microsoft Excel is a spreadsheet application that supports data input, manipulation, and storage. This being the case, many applications enable their users to enter their data in Excel and then upload it into the system by accepting the binary Microsoft Excel files as input.

Because these types of problems exist, there are Perl modules designed to help you solve them. Remember, someone has probably already run into the problem you're having. SAXDriver modules are designed to facilitate converting other data formats into XML by giving you the flexibility of providing your own conversion rules and by being very efficient and light-weight (that is, small memory footprint). These are important qualities that would enable you to deploy these applications in a critical production environment and deal with large XML documents. Imagine the tasks that you could accomplish if you create an XML communication middleware application, and then effortlessly adapt any other format by converting it to XML without having to change the middleware business rules. Currently, two Perl modules enable you to easily accomplish this task: XML::SAXDriver::CSV and XML::SAXDriver::Excel. Let's take a closer look at these modules.