XML (Extensible Markup Language)

GISBox is a one-stop 3D GIS data editing, conversion and publishing platform that supports editing in multiple GIS formats such as OSGB/GEOTIFF/RVT, converting to 3DTiles/Terrain and publishing.

Introduction

XML (Extensible Markup Language) is a markup language used to describe and store structured data. Its tag structure is similar to HTML, but its purpose is specifically for expressing and exchanging data, and users can define their own tags. It is mainly used for data integration between systems, setting files, configuration information, etc.

File Structure

: declaration part. Describes the version and character code.
: called the basic unit of element.
Attribute: additional information attached to the tag. For example:
Nested structure can be implemented to express data hierarchy.

Pros

Easy to read by humans and machines: Since it is written in plain text, it can be easily reviewed and edited using an editor.
Self-describing data: Tags express the meaning of the data, making its structure and content clear.
Highly extensible: Arbitrary tags can be defined and can accommodate a variety of data structures.
Compatibility with standard technologies: It can be combined with technologies such as XSLT, XPath, DOM, SAX, etc. for advanced operations.
Support for multiple languages and software: XML parsers are standardly supported in multiple languages, including Java, Python, C#, etc., so it can be used in a wide range of environments.

Cons

The amount of data tends to be large: Due to redundant tag descriptions, the file size tends to be larger than JSON, etc., even if the content is the same.
Parsing speed may be slow: Reading and parsing large XML files is computationally intensive.
Learning cost: Even if it looks simple, you still need to understand DTD, schema, namespace, etc.

Application Scenario

It is to be used as a common format for data sharing and APIs between companies. It is used to describe the configuration of software and applications. Microsoft Office products (.docx, .xlsx, etc.) are internally based on XML. It is used as a standard format for describing geospatial data, such as GML (Geography Markup Language). It is used in XML-based web service protocols, such as SOAP (Simple Object Access Protocol).