imgLazyLoading()

为图片添加 loading="lazy" 属性以实现延迟加载。

import { imgLazyLoading } from "@unifast/node";

签名

function imgLazyLoading(options?: ImgLazyLoadingPluginOptions): UnifastPlugin

参数

options?

懒加载行为的配置

属性类型默认值描述
skipFirstnumber0跳过前若干张图片（例如跳过首屏主图）

该插件会为匹配到的 <img> 元素同时添加 loading="lazy" 和 decoding="async" 属性，包括嵌套在其他元素内部的图片。

用法

import { compile, imgLazyLoading } from "@unifast/node";

const md = `
![Photo 1](photo1.jpg)

![Photo 2](photo2.jpg)

![Photo 3](photo3.jpg)
`;

const result = compile(md, {
  plugins: [imgLazyLoading()],
});

// All images get loading="lazy" and decoding="async":
// <img src="photo1.jpg" alt="Photo 1" loading="lazy" decoding="async">
// <img src="photo2.jpg" alt="Photo 2" loading="lazy" decoding="async">
// <img src="photo3.jpg" alt="Photo 3" loading="lazy" decoding="async">

示例

跳过首张图片（首屏主图模式）

页面上的第一张图片通常是首屏主图或横幅，应当立即加载。可以使用 skipFirst 将它排除在懒加载之外：

import { compile, imgLazyLoading } from "@unifast/node";

const md = `
![Hero banner](hero.jpg)

Some introductory content...

![Diagram](diagram.jpg)

More content...

![Screenshot](screenshot.jpg)
`;

const result = compile(md, {
  plugins: [
    imgLazyLoading({
      skipFirst: 1,
    }),
  ],
});

// First image loads eagerly (no loading attribute):
// <img src="hero.jpg" alt="Hero banner">
//
// Remaining images are lazy loaded:
// <img src="diagram.jpg" alt="Diagram" loading="lazy" decoding="async">
// <img src="screenshot.jpg" alt="Screenshot" loading="lazy" decoding="async">

跳过多张首屏可见图片

import { compile, imgLazyLoading } from "@unifast/node";

const result = compile(md, {
  plugins: [
    imgLazyLoading({
      skipFirst: 3, // skip the first 3 images
    }),
  ],
});