Exploring XML: A Beginner's Journey
Tags: xml, community, programming, beginners
Published: 2023-09-16 08:42:25

Recently, I had the opportunity to attend a programming event at Oxford University in the UK focused on using XML and related technologies. 

As someone relatively new to programming, this served as my first real introduction to XML. And in this post, I wanted to share some of my key takeaways from learning XML this week.  

Prior to taking this course, I had a limited understanding of XML. I knew it was an extensible markup language used to create electronic documents, but that was the extent of my knowledge. Fortunately, this course gave me a solid foundation in XML terminology and best practices.

## Key XML Terminology

Let's start by exploring some fundamental XML terminology that I learned during the course:

## What is XML?

A language for marking up electronic documents in a way that seperates their structure from content. 

**Advantages of XML**

Here are the key XML advantages:

- Separates structure from content.
- Universally readable open format.
- Applicable on both client and server.
- Enables data exchange between different systems.
- Widely supported in various languages/runtimes.
 
**Drawbacks of XML**

- XML may not be ideal for very large datasets (JSON might be better in some cases).
- Images and other data types aren't represented well in the XML language.
- XML can quickly become hard to read in complex scenarios.


**What is Schema?**

XML Schema is a set of rules that define the document type. These rules make them easier to validate and process. 

**What is DTDs?**

Document Type Definitions or (DTDs) is a grammer based language that defines the structure of the elements and attributes of an XML document. 

**What is a stylesheet?**

A stylesheet is a set of rules used for transforming XML documents. 

![CMS](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ql07c32a4t4ktik5ub4l.png)

**What is XPath?**

XPath is used to navigate through elements and attributes in an XML document. It acts as a querying mechanism, enabling you to locate and retrieve specific data points efficiently.

**What is XQuery?**

XQuery is a query language that allows you to make modifications to XML data. It provides a way to extract, manipulate and query XML documents in a database. 

**What is XSLT?**

XSL (eXtensible Stylesheet Language) is a styling language specifically tailored for XML.

**Advantages of XSLT**

Here are some advantage to XSLT: 

- Transformation with XSLT
- Client-side XSLT is surprisingly well supported

**Drawbacks of XSLT**

Client-side XSLT has two disadvantages:

- It's invisible to search engines
- It's stuck in XSLT version 1

## Key Golden Rules

I also learned some valuable golden rules that are worth remembering:

**XML is Stable**

One of the strengths of XML is its very stable. This stability means that XML is a reliable choice for long-term data storage and exchange.

**Invest for the Future**

When working with XML, consider it an investment in the future.  XML's adaptability allows it to accommodate evolving requirements and technologies, ensuring that your data remains relevant.

**Don't Reinvent the Wheel**

XML is open source, and it's easy to write software to process it. Most of the tasks you might want to perform with XML have likely been done before, and many resources are available for free. Leverage existing solutions to save time and effort.

**Good Structure = Good Sense**

While a well-structured XML document can be validated, it's important to remember that validation alone doesn't guarantee that the content makes sense. Quality assurance is still necessary to ensure that the data is accurate and meaningful.

**XML Isn't the Answer to Everything**

XML is a useful way to create and exchange structured information. However, it's not a one-size-fits-all solution for every information technology problem. 
 
## Conclusion

Overall, this XML programming course gave me a comprehensive introduction to an essential markup language. As I've learned the last week, XML's potential is vast, and I'm looking forward to putting my new skills into practice!

## W3C References

[The XPath, XQuery and XSLT standard library of functions. ](https://www.w3.org/TR/xpath-functions-31/)

[XQuery 3.1: An XML Query Language](https://www.w3.org/TR/xquery-31/)

[XSLT and XQuery Serialization 3.1](https://www.w3.org/TR/xslt-xquery-serialization-31/)

## Oxygen XML Editor

[Download Oxygen XML Editor](https://www.oxygenxml.com/xml_editor/download_oxygenxml_editor.html)

## Regexper Reference

[Regular Expression Visualization Site](https://regexper.com/)

## Exist-DB Reference

[eXist-DB Documentation](https://exist-db.org/exist/apps/doc/)

## XQuery Wikibook reference

https://en.wikibooks.org/wiki/XQuery