Web Emerging Technologies

2R - CSS Nesting

AI Generated

Research and Document the concept of CSS nesting. Discuss the origins of CSS nesting. Discuss the use of the ampersand as nesting selector. Discuss browser support based on data from the caniuse.com website.

My Prompt

"Provide me with the origins of CSS nesting. Discuss the use of the ampersand as nesting selector. Provide me with a list of supported browsers from the caniuse.com website." prompt. Gemini, Pro 1.0, Alphabet/Google, 04 Apr. 2024, https://gemini.google.com/.

Gemini Response

Ampersand (&) as Nesting Selector

The ampersand (&) symbol plays a crucial role in CSS nesting. It acts as a placeholder that refers to the selector of the parent rule. This allows you to create child selectors within the nested block without repeating the entire parent selector. For instance, consider this code:

CSS

.menu {
  background-color: #f0f0f0;
  padding: 10px;

  & a {
    color: #000;
    text-decoration: none;
  }
}

Here, the & a selector targets all anchor tags (a) that are descendants of elements with the class menu. The ampersand (&) effectively replaces the .menu part, resulting in a more concise and readable style definition.

Browser Support for CSS Nesting

As of today (April 4, 2024), native CSS nesting isn't universally supported across all browsers. You can check for compatibility on caniuse.com: CSS nesting Can I Use:https://caniuse.com/?search=nesting

Here's a brief summary of browser support for CSS nesting:

• Supported: Firefox (behind a flag), Chrome (behind a flag).
• Not Supported: Safari, Edge, Internet Explorer.

It's important to consider browser compatibility when using CSS nesting in your projects. You might need to use workarounds or polyfills to ensure consistent styling across different browsers.

My Content

CSS

.nesting-demo {
  font-size: 2em;

  & p {
    text-transform: uppercase;
    justify-content: right;
    list-style: none;
    color: green;
  }

  & a {
    text-transform: capitalize;
    color: red;
  }

}
          

Demo

In this example, there is a div element utilizing the .nesting-demo class to style a paragraph and an anchor tag.

The ampersand is used as a the parent selector, and is a reference to the parent selector that is housing the nested CSS. The ampersand specifically is not the only symbol that can be used for nesting, but a symbol is needed for every element selector.

CSS nesting can be used for code readability, and as a nice solution for instances where you have multiple contextual variations of a similar element, such as links or buttons.