# 📊 Stats

[![Build Status](https://travis-ci.org/helpscout/stats.svg?branch=master)](https://travis-ci.org/helpscout/stats)
[![npm version](https://badge.fury.io/js/%40helpscout%2Fstats.svg)](https://badge.fury.io/js/%40helpscout%2Fstats)

> Easy performance monitoring for JavaScript / React

![Stats](https://raw.githubusercontent.com/helpscout/stats/master/images/stats-demo.gif)

## Table of Contents

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- [Installation](#installation)
- [Usage](#usage)
  - [JavaScript](#javascript)
  - [React](#react)
- [Graphs](#graphs)
- [Options](#options)
- [Thanks](#thanks)

<!-- END doctoc generated TOC please keep comment here to allow auto update -->

## Installation

Add `stats` to your project via `npm install`:

```
npm install --save @helpscout/stats
```

## Usage

### JavaScript

To use Stats in your JavaScript project, simply import it and instantiate!

```js
import createStats from '@helpscout/stats'

const stats = createStats()
// Stats will automatically mount to window.document

// For clean up, execute the destroy() method
stats.destroy()
```

### React

Stats comes with a handy `<StatsGraph />` component. To add it to your React project, import it and render it:

```jsx
import React from 'react'
import {StatsGraph} from '@helpscout/stats'

class App extends React.Component {
  render() {
    return (
      <div>
        ...
        <StatsGraph />
        ...
      </div>
    )
  }
}

export default App
```

`StatsGraph` cleans up after itself if it unmounts.

## Graphs

- **FPS** Frames rendered in the last second. The higher the number the better.
- **MB** MBytes of allocated memory. (Run Chrome with --enable-precise-memory-info)
- **NODES** Number of DOM nodes in `window.document` (including iFrame nodes).

## Options

Stats accepts a handful of options to adjust it's position and UI.

| Prop     | Type              | Default  | Description                 |
| -------- | ----------------- | -------- | --------------------------- |
| top      | `number`/`string` | 0        | (CSS) top position.         |
| right    | `number`/`string` | 0        | (CSS) right position.       |
| bottom   | `number`/`string` | 0        | (CSS) bottom position.      |
| left     | `number`/`string` | 0        | (CSS) left position.        |
| opacity  | `number`          | 0.5      | Opacity for the Stats UI.   |
| position | `string`          | fixed    | Position for the Stats UI.  |
| zIndex   | `string`          | 99999999 | `z-index` for the Stats UI. |

The React `StatsGraph` uses the same options for it's `defaultProps`

## Thanks

Thanks for [mrdoob](https://github.com/mrdoob) for his [stats.js](https://github.com/mrdoob/stats.js) library, which inspired this one!