Define CSS Portal

What is CSS Portal?

A feature introduced in the CSS Containment specification is called a "portal" in CSS. By enabling developers to isolate specific page elements from the rest of the page, CSS Containment gives them greater control over how quickly web pages render by limiting the amount of layout and rendering calculations needed.

A portal is a container element that serves as a boundary or wall for its contents in the context of CSS containment. It establishes a new formatting and stacking context for the contained elements. This isolation can aid in rendering optimization and performance improvement when dealing with complex or dynamically changing content.

They contain a portal; value precisely activates the portal containment when they contain: the property is used to enable containment on an element. By applying this property to the container element, you can tell a browser that the content inside a container element should be handled as a distinct entity with its rendering context.

Example:

Here is an illustration of how to make use of the contain: portal; asset:

The.portal-container elements contain portal; property tells the browser to create a portal containment for its contents. This containment can optimize rendering and improve performance when the content inside the container is frequently changing or animated.

Why We Use Portal CSS?

There are several benefits to using portals in CSS, particularly with the contain portal; property.

• Performance Optimization: By separating the contained elements from the rest of the page, portals can aid in improving rendering performance. The browser can optimize the rendering and layout calculations within the portal by creating a new rendering context, lessening the impact on other page areas.
• Preventing Extraneous Layouts: The containment boundary ensures that when an element inside a portal is changed or animated, the browser only needs to recalculate the layout inside that particular portal, not the entire page. This can be especially helpful when dealing with complex or dynamically changing content, as it helps reduce extra layout calculations.
• Reducing Paint Areas: By enclosing elements inside a portal, the browser can isolate the rendering of those elements, possibly lowering the total number of paint areas and enhancing rendering speed. This is especially useful when working with large, visually complex elements or animations.
• Encapsulation and Isolation: Portals offer a way to isolate and encapsulate particular web page components, enabling those components to operate independently. This can be helpful for widgets, components, or sections that need to maintain their separation from the styling of the rest of the page or have their layout requirements.

How We Can Use CSS Portal

Here's an example of how we can use CSS portal containment in your HTML and CSS code:

HTML:

CSS:

Explanation:

• As the previous example shows, our portal container is a div> element with the class "portal-container".
• To style the container element, we use the CSS property.portal-container.
• They contain a portal; the property enables portal containment on this element.
• We added some CSS rules t
• o show how the container is styled, like a black border and padding.
• Using this code, the browser can optimize the rendering and layout calculations within the portal by isolating the content within the.portal-container.
• The rest of the page will be less affected by any changes or animations made to the content inside the container, potentially improving performance.

Limitation of CSS Portal

Although CSS portals can aid in encapsulation and improve performance, it's important to be aware of their limitations:

• Browser Support: As of my knowledge cutoff in September 2021, browser support for CSS portals is very limited. A browser's partial or lack of support for portals may impact your code's cross-browser compatibility. Verifying the current browser support is critical before using CSS portals in a production environment.
• Impact on performance: While portals can boost performance in some circumstances, they might only sometimes offer noticeable advantages, especially for simpler web pages or components. To ascertain whether the benefits of using portals are sufficient to justify their implementation, it is crucial to measure and profile the performance of your particular use case.
• Maintenance and Complexity: Adding portals to your CSS code can make it more challenging to maintain, especially when working with larger projects or teams. It can be more work to manage the containment boundaries and comprehend how they affect the layout and rendering. Additionally, the code that uses portals may need to be updated and maintained.
• Limited Use Cases: CSS portals are most helpful when dealing with complex or dynamically changing content inside a particular container. The advantages of using portals may only be substantial if your web page or component meets these specifications. Before implementing portals, it's critical to determine whether they are necessary for your particular use case.