Join Joe Marini for an in-depth discussion in this video XML-related technologies, part of XML Essential Training.
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In addition to XML itself, there are certain related technologies that make working with XML to solve certain problems easier and more productive. And we'll take a look at those now. The first is called XPath, which stands for eXtensible Path Language. Now the reason it's called XPath is because if you've ever worked with folder and directory names and filenames, you'll notice that most computer systems organize those as a path. So there's a route drive, and that's followed by some folder names down to a filename.
And all of those are usually separated by some kind of path character, like a slash or a colon. XPath is very similar, and it's used to find and extract information from XML documents. The next is called XSLT, and that stands for XML Stylesheet Language Transformations. Now, you might see the word stylesheet and think, oh, okay, this is kind of like CSS. And it sort of is. XSLT can be used to style XML information, but the real important word there is transformations.
XSLT is a way of taking XML information and transforming it into something else. Now that something else could be another XML format, or it could be PDF, or it could be a text file, or it could be a web page. It can be pretty much just about any other kind of file format. So that's essentially what XSLT is used for. Next up is XQuery. XQuery, you can think of as sort of a querying language, like a database language, like SQL except for XML.
Now, XQuery is more advanced querying than XPath. In fact, XPath is sort of just a derivative of XQuery, but it's used for extracting information in a very advanced way from XML data. Using XQuery, you can build really complex queries that search multiple XML files to extract information. Then there's XPointer and XLink. XPointer and XLink create links between and within XML documents. And conceptually, you can think of this as similar to the link tag in HTML, only a lot more powerful.
Now those last three, XQuery, XPointer, and XLink, are pretty fairly advanced, and they can take up an entire course on their own. So, in this course, we're only going to focus on XPath and XSLT, which we will see later on in the course.
- What is XML?
- The advantages and drawbacks of XML
- Proper XML syntax
- Working with namespaces
- Styling XML tags with CSS
- Extracting and manipulating data
- Taking XPath and XSLT for a spin
- Creating document type definitions and schema definitions