The Document Object Model, commonly known as DOM, is a programming interface for HTML and XML documents. It represents the structure of a document as a tree-like hierarchy where each node is an object representing a part of the document. Here are key aspects of the DOM:
Definition and Purpose
- The DOM provides a structured representation of documents and enables programs to dynamically access and manipulate the content, structure, and style of documents.
- It's platform- and language-neutral, allowing it to be used in various environments like web browsers, server-side scripting, and even with non-web technologies.
History
- The DOM was developed by the World Wide Web Consortium (W3C) as part of the effort to standardize web technologies.
- Its initial specification was released in 1998, with subsequent versions and levels of the specification released to address different aspects and requirements of document manipulation.
Structure
- Nodes: Every element, attribute, and piece of text in an HTML document is represented by a Node in the DOM tree.
- Document: The root node of the tree is the Document node, which represents the entire document itself.
- Element: These nodes represent HTML elements like
<div>, <p>, or <img>.
- Text: Text nodes contain the actual text within elements.
- Attribute: Attributes of elements are also nodes in the DOM.
Levels and Versions
- Level 0: Not an official specification but refers to the basic DOM functionality that was available before formal standardization.
- Level 1: Introduced the core structure and basic interaction with HTML documents.
- Level 2: Expanded on Level 1, introducing features like event handling, CSS manipulation, and XML namespaces.
- Level 3: Further enhancements including better support for XML, XPath, and DOM3 Events.
- Level 4 and beyond: Continuing to evolve with new APIs and methods to better support modern web applications.
Usage
- JavaScript is commonly used to interact with the DOM in web browsers, allowing for dynamic content modification.
- APIs like DOM API provide methods and properties to manipulate the DOM tree.
External Links
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