Just what Is XPath?

XPath is a W3C standard and language which can be used to find info or data from an XML file, it’s very good for navigating through elements and attributes in a simple manner.

The best way to look at it is something such as find and replace function in MS Word, however XPath is a lot more advanced than this with its own rules, syntax, structure as well as other such rigorous criteria, nevertheless the more familiar you become with XPath the easier it will get, for me, these days it is more second nature.

The other point to consider is, just how important is XPath. In the grand scheme of things, you may almost certainly cope without it, in reality whatever that you can do with XPath when working with an XML document, you are able to realize without XPath too, and so in that sense it's not essential, it can be handy.

As an example, utilizing XPath presents several benefits with regards to application development and dealing with XML documents, like speed, ease, effectiveness, productivity, simplicity etc etc

A very important differentiation to note is also that XPath is not really an XML language, though it may be closely connected with XML, it's really a method for querying XML documents, but being related to XML, it’s also employed in related specifications and languages like XSLT as well as in DOM implementations.

Don't forget that XML is nothing at all but a textual representation of associated nodes in a tree like design. There are seven core nodes in XPath, these are Root, Element, Text, Attribute, Comment, Processing instruction and Namespace nodes.

If you're accustomed to programming syntax and taxonomy, these kind of terms will not be uncommon however for those with no programming background, I am going to quickly elaborate.

The root node is the top or upper most part of an XML document, or in our tree analogy, it is the root from which the branches or elements spring from.

An element is a component of the data, by way of example in an xml file concerning customers, an element may just be the first name or customer id. The element alone can easily contain text or attribute based information.

Commenting is also enabled in an XML document. These are a bit synonymous to XPath as well, but a bit distinctive in some aspects.

And many of the apparent features of XPath, you can also find quite a few not so apparent, such as, in XPath, the tree’s root node is not the same as its root element.

The tree’s root node has the entire document, including the root element and also comments and processing instructions that occur prior to the root element start tag or following the root element end tag.

Also, the XPath data models doesn’t have everything in the xml document, for instance the XML declaration and the DTD. Nevertheless, you may give a default value for your attributes and this will be recognized by XPath.

Last of all, I should point out that in XPath, the xmlns attributes aren't considered attribute nodes but instead namespace nodes, yet any non-namespace aware parser will view them as an attribute.

More info on XPath can be found at W3C schools or you can consider this XPath tutorial.