Reduced DOM Manipulations Using DOM Diffing Algorithm

The Document Object Model (DOM) diffing algorithm, commonly known as the "virtual DOM diffing algorithm," is a method implemented in front-end web development frameworks such as React to promptly update the user interface when the application state changes.

The algorithm aims to minimize actual DOM manipulations since manipulating the real DOM can be costly in terms of performance. In fact, the algorithm listens for state changes and updates the corresponding section in the DOM after comparing the relevant node.

You can see a simple diff algorithm logic in the picture below. The algorithm can be more efficient with optimization and smart instructions.

Initial Render : At the start of the application or when a component first renders, a virtual DOM is formed, which is a JavaScript object reflecting the structure of the real DOM.

Updated: When the application state changes due to user interactions or data fetching, the virtual DOM is re-rendered to reflect the updated state.

Create New Virtual DOM: A new virtual DOM is generated utilizing the modified state. appearance of the DOM.

Diffing: The diffing algorithm compares the new virtual DOM tree to the previous one and identifies the discrepancies, also known as "diffs," between the two trees.

Reconciliation: After identifying differences, calculate the minimum changes required to update the real DOM. This set of changes is commonly known as a "diff" or "patch."

Applying Changes: The computed alterations are subsequently implemented on the actual DOM to synchronize it with the updated virtual DOM. This involves creating, updating, or removing actual DOM elements based on the differences identified during the diffing phase.

Efficiency is a consideration: To increase performance, diffing algorithms frequently employ heuristics and strategies to reduce the number of DOM manipulations. For instance, certain algorithms prioritize updating identical element types and consolidate changes, resulting in more efficient rendering.

By following this process, the virtual DOM diffing algorithm helps ensure that the actual DOM is updated only where necessary, reducing performance bottlenecks associated with frequent DOM manipulations. This approach is a crucial factor in the success of modern front-end frameworks, including React, which leverage the virtual DOM.