# longtask-observer

> [以用户为中心的性能指标](https://web.dev/user-centric-performance-metrics/) 中提出，与用户感知的指标包含：

Latest version **0.0.2** (published 2022-08-01) · ISC license · 0 weekly downloads

## Install

```sh
npm install longtask-observer
pnpm add longtask-observer
yarn add longtask-observer
bun add longtask-observer
```

## Health

**Score 20/100 (F)** — status: abandoned.

Positive: has types; no vulnerabilities.

Warnings: low downloads; no esm support; pre 1.0.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.0.2 |
| Published | 2022-08-01 |
| First published | 2022-08-01 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | bundled |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 19.9 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 2 |
| Maintainers | imaoda |

## Links

- npm: https://www.npmjs.com/package/longtask-observer
- Repository: https://github.com/imaoda/longtask-observer
- Homepage: https://github.com/imaoda/longtask-observer#readme
- Issues: https://github.com/imaoda/longtask-observer/issues
- npm.io page: https://npm.io/package/longtask-observer

## Recent versions

- 0.0.2 (latest) — 2022-08-01
- 0.0.1 — 2022-08-01

## README

## introduction

[以用户为中心的性能指标](https://web.dev/user-centric-performance-metrics/) 中提出，与用户感知的指标包含：

- 加载速度
- 视觉稳定度
- 平滑度
- 👉 **运行时响应速度**

我们提供了 **运行时响应速度** 的解决方案，可以方便的监测你的某个任务阻塞了多长时间，便于性能统计与优化

## usage

```typescript
import longtaskObserver from "longtask-observer";

// 在点击时，进行打点
window.addEventListener("click", () => {
  longtaskObserver.tag("页面的点击");
});

// 绑定长时任务的回调
const handler = (longtaskInfo) => {
  console.log(longtaskInfo.name, longtaskInfo.duration);
  // 页面的点击  350
};

longtaskObserver.on(handler);
```

## Q&A

### Q：任务执行和 tag 的顺序是否要严格保障

A：无需特别留意，会进行智能匹配，例如下面两种写法，都是可以的：

写法 1

```typescript
longtaskObserver.tag("user click");
doSomeLongTask();
```

写法 2

```typescript
doSomeLongTask();
longtaskObserver.tag("user click");
```

这两中写法，都会统计到 user click 行为所耗费的时长，并且结果一致

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_Source: https://npm.io/package/longtask-observer · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._