What is the DOM Data Structure? Document Object Model

Do you love programming? Do you love it enough to dedicate your professional career to it? As you well know, the field of programming is very broad and has many different specializations. Today we will look at everything you need to know about the DOM (Document Object Model) data structure model.

What is the DOM Model?

The Document Object Model (abbreviated DOM) is an application programming interface for HTML and XML documents. The DOM data structure model defines the logical structure of documents and the ways to access and manipulate them. Using the Document Object Model, programmers can create documents, navigate their structure, and add, modify, or delete elements and content.

One of the most important goals of creating the DOM is to provide a standard programming interface that can be used in various environments and applications. Also important is the fact that the DOM can be used with any programming language, can be implemented in any computing environment, and does not require linking object libraries.

It can be said that the DOM data structure model is a programming API for documents, capable of merging with the structure of the modeled document.

Document Object Model or DOM Structure

Documents are modeled using objects, so the model understands the document's structure and the behavior of the document and the objects that compose it. Thus, the DOM can identify:

• Interfaces and objects used to represent and manipulate the document
• The semantics of these interfaces and objects, including their behavior and attributes
• The relationships and interactions between these interfaces and objects.

The DOM data structure model consists of two parts – the core DOM and the HTML DOM. The core DOM provides functionality used for working with XML documents and also serves as the foundation for the HTML DOM. Additionally, its function is to implement either the HTML DOM or advanced interfaces (XML), or both, all with defined semantics.

DOM Data Structure

In the world of web programming, the DOM defines interfaces that can be used to work with XML or HTML documents. In the future, the DOM specification is expected to include:

• A structural model for both internal and external subsets.
• Validation for schemas.
• Document presentation management via style sheets.
• Access control.
• Thread or process safety.
• Events.

In the DOM, documents are represented as a tree-like structure, creating a hierarchy where multiple secondary objects can depend on a main object. This is clearly visible in the structure of an HTML page, which consists of nested tags.

The DOM data structure consists of nodes that are connected to each other in a hierarchical structure, with each node having a parent node on which it depends – the parent node. Additionally, each node can have 0, 1, or several dependent nodes called child nodes.

Nodes at the same level and dependent on the same parent node are called sibling nodes. In this curious family of nodes, the entire DOM tree depends on the main node from which all nodes originate – the Document node.

Node types

• Document: the root node from which all others descend.
• Element: each of the HTML tags. This is the only node that can contain attributes and from which other nodes can descend.
• Attr: each tag attribute creates an Attr node, which also contains its value (as a property). It is a child node of the containing element (tag).
• Text: Contains the text enclosed in an HTML tag (child node of an Element).
• Comment: comments included in the HTML page also create their own nodes.

There are other node types used in XML, but when used within HTML, they are usually well-defined, fixed elements. These include:

• CDATASection: a node that can contain escape characters typed normally.
• Document Type: the Doctype declaration or tag.
• DocumentFragment: a fragment or part of the DOM tree that allows JavaScript to select a portion of the document.
• Entity: a control character or entity in XML.
• EntityReference: a reference to an XML entity.
• Processing Instruction
• Notation: similar to a "comment", but can be displayed on the screen in XML format.

As you can see, the DOM data structure or Document Object Model is used by most programming languages (especially XML and HTML) as a reference for organizing syntax. If you also want to work with the DOM, know its features, understand it, and "speak" its language, then you will obviously need specialized training to prove that you are a professional in web programming.