# :tada:vite-plugin-cesium-build

English | [简体中文](/README.zh-CN.md)

It externalizes `Cesium.js` and automatically copies the four major libraries and core files of CesiumJS during the build process.

It also support [@cesium/engine](https://community.cesium.com/t/cesium-engine-and-cesium-widgets-are-now-available-for-testing/20898) !

- :+1: **DX** Zero impact on development
- :sparkles: **TypeScript** Type support.
- :rocket: **Super fast!** In my laptop, the sample project only takes 300ms to complete the build because the Cesium library is not involved in the core build.

![Alt text](readme-image.png)

## :memo: Usage

> If you are `"not interested in document just wanna make it work asap"`, please refer to [examples](https://github.com/s3xysteak/vite-plugin-cesium-build/tree/main/examples).

Install this plugin

```sh
pnpm add -D vite-plugin-cesium-build
```

Import it in `vite.config.js`

```javascript
import { defineConfig } from 'vite'
import cesium from 'vite-plugin-cesium-build'
// import cesium from 'vite-plugin-cesium-build/engine' // when using @cesium/engine

export default defineConfig({
  plugins: [
    // ...
    cesium()
  ]
})
```

You have completed the entire configuration for CesiumJS! Now you can continue development and build as usual!
By default, This plugin will automatically add the code to your `index.html`:

```javascript
// Customize variable 'to' in options
Object.defineProperty(globalThis, 'CESIUM_BASE_URL', {
  value: `/${to}/`
})
```

To prevent it, see `customCesiumBaseUrl` in Options.

If using Cesium version 1.97 or older, you can set `css` option to `true`:

```javascript
export default defineConfig({
  plugins: [
    cesium({ css: true })
  ]
})
```

That will automatically add Cesium's css to your `index.html`:

```html
<link rel="stylesheet" href="./cesium-package/Widgets/widgets.css">
```

In default it will import Cesium.js as IIFE, which could skip the long building time. If you want to import on demand, set `iife: false`:

```javascript
export default defineConfig({
  plugins: [
    cesium({ iife: false })
  ]
})
```

Then you can import on demand through ESM.

> [!TIP]
> When `iife: false`, you can improve the behavior of cache in production environments by vite option `build.rolldownOptions.output.manualChunks`.
>
> For example:
> ```ts
> export default defineConfig({
>   build: {
>     rolldownOptions: {
>       output: {
>         manualChunks(id) {
>           if (id.includes('node_modules/cesium')) {
>             return 'cesium'
>           }
>         }
>       }
>     }
>   }
> })
> ```
>
> (before Vite8, using `rollupOptions` instead of `rolldownOptions`)

## :wrench: Options

In addition, the plugin provides some configuration options:

```javascript
export default defineConfig({
  plugins: [
    cesium({
      /**
       * Specifies the location of the Cesium package folder
       * Which means the relevant resources of CesiumJS will be obtained from this folder
       */
      from: 'node_modules/cesium/Build/Cesium',

      /**
       * Specifies the location of the built resources
       * Which means the built resources will be placed under /dist/cesium-package/
       */
      to: 'cesium-package',

      /**
       * If `true`, you need to manually set the CESIUM_BASE_URL. Or use `string` to customize the base url directly.
       */
      customCesiumBaseUrl: false,
      /**
       * If `true`, Cesium's css will be added automatically.
       */
      css: false,

      /**
       * If `true`, using IIFE to skip building `Cesium.js`. If `false`, do not handle `Cesium.js`.
       */
      iife: true
    })
  ]
})
```

## Fully customizable

It also provide some internal methods to support fully customizable. In the rare case that it is necessary, please check the corresponding source code.

```js
import { defineConfig } from 'vite'
import { imports, setBaseUrl } from 'vite-plugin-cesium-build/core'

export default defineConfig({
  plugins: [
    [
      imports(
        // ...
      ),
      setBaseUrl(
        // ...
      )
    ]
  ]
})
```

## Others

If you are a Vue user, maybe try [cesium-use](https://s3xysteak.github.io/cesium-use/) !