Parsing is largely a matter of manipulating strings. Since there are so many string manipulation methods in PHP, it can be daunting for the beginner to decide which approach to take when developing a parsing strategy for a specific web page. I will show you how nearly any web page can be parsed with amazingly few methods—and by limiting yourself to a handful of methods, the entire parsing-development process goes more smoothly. For this reason, I simplified parsing by identifying a few useful functions and placing them into a library called LIB_parse. Primarily, LIB_parse contains wrapper functions that provide simple interfaces to otherwise complicated routines. These functions (or a combination of them) provide everything needed for 99 percent of your parsing tasks.

Whether or not you use the functions in LIB_parse, I urge you to standardize your parsing routines. Standardized parse functions make your scripts easier to read and faster to write. Perhaps just as importantly, when you limit your parsing options to a few simple solutions, you’re forced to consider simpler approaches to parsing problems.

To use the examples in this book, download the latest version of LIB_parse from this book’s website, http://www.WebbotsSpidersScreenScrapers.com.