DOMtasojen

DOMtasojen is a concept in Finnish web development referring to a layered model of the Document Object Model (DOM). The model aims to clarify how different responsibilities within a web page are distributed across distinct levels to improve maintainability, performance, and accessibility.

The typical levels are: structural level (the node tree and document structure), styling level (the CSS Object Model and computed styles), interaction level (the DOM APIs used by JavaScript for manipulation and event handling), and accessibility level (semantic information, ARIA roles, and support for assistive technology). Each level describes a different aspect of how the DOM is produced, presented, and interacted with.

Origin and scope: The term arose in developer discussions and tutorials in the 2010s as a pedagogical tool rather than a formal standard. Official browser behavior follows the DOM specifications published by WHATWG and W3C, while DOMtasojen serves as a mental model for architects and educators.

Applications and implications: Using a layered view can help teams reason about performance bottlenecks, such as excessive reflows in the structural level or heavy script-driven mutations in the interaction level. It also reinforces accessibility considerations during development and testing.

See also: Document Object Model, CSS Object Model, ARIA, JavaScript, Web accessibility.