eta (η)
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**You're viewing the source for Eta v4**
## Summary
Eta is a lightweight and blazing fast embedded JS templating engine that works inside Node, Deno, and the browser. It's written in TypeScript and emphasizes great performance, configurability, and small bundle size.
> 🎯 **Built with [ts-base](https://github.com/bgub/ts-base)** — A TypeScript library starter template featuring Biome, Vitest, tsdown, and automated releases. Check out ts-base for a modern TypeScript project setup!
### 🌟 Features
- 📦 0 dependencies
- 💡 Only ~3.5 KB minzipped
- ⚡️ Written in TypeScript
- ✨ Deno support (+ Node and browser)
- 🚀 Super Fast
- 🔧 Configurable
- Plugins, custom delimiters, caching
- 🔨 Powerful
- Precompilation, partials, async, blocks
- **Layout support**!
- 🔥 Reliable
- Better quotes/comments support
- _ex._ `<%= someval + "string %>" %>` compiles correctly, while it fails with doT or EJS
- Great error reporting
- ⚡️ Exports ES Modules
- 📝 Easy template syntax
## Get Started
_For more thorough documentation, visit [https://eta.js.org](https://eta.js.org)_
Install Eta
```bash
npm install eta
```
In the root of your project, create `templates/simple.eta`
```eta
Hi <%= it.name %>!
```
Then, in your JS file:
```js
import { Eta } from "eta";
// or use https://jsr.io/@bgub/eta
const eta = new Eta({ views: path.join(__dirname, "templates") });
// Render a template
const res = eta.render("./simple", { name: "Ben" });
console.log(res); // Hi Ben!
```
## FAQs
Where did Eta's name come from?
"Eta" means tiny in Esperanto. Plus, it can be used as an acronym for all sorts of cool phrases: "ECMAScript Template Awesomeness", "Embedded Templating Alternative", etc....
Additionally, Eta is a letter of the Greek alphabet (it stands for all sorts of cool things in various mathematical fields, including efficiency) and is three letters long (perfect for a file extension).
## Integrations
Visual Studio Code
[@shadowtime2000](https://github.com/shadowtime2000) created [eta-vscode](https://marketplace.visualstudio.com/items?itemName=shadowtime2000.eta-vscode).
ESLint
[eslint-plugin-eta](https://github.com/eta-dev/eslint-plugin-eta) was created to provide an ESLint processor so you can lint your Eta templates.
Webpack
Currently there is no official Webpack integration but [@clshortfuse](https://github.com/clshortfuse) shared the loader he uses:
```javascript
{
loader: 'html-loader',
options: {
preprocessor(content, loaderContext) {
return eta.render(content, {}, { filename: loaderContext.resourcePath });
},
},
}
```
Node-RED
To operate with Eta templates in Node-RED: [@ralphwetzel/node-red-contrib-eta](https://flows.nodered.org/node/@ralphwetzel/node-red-contrib-eta)
Koa
To render Eta templates in [Koa](https://koajs.com) web framework: [@cedx/koa-eta](https://github.com/cedx/koa-eta/wiki)
Vite
To use Eta templates in your Vite project: [@rinoshiyo/vite-plugin-eta](https://github.com/rinoshiyo/vite-plugin-eta)
## Projects using `eta`
- [Docusaurus v2](https://v2.docusaurus.io): open-source documentation framework that uses Eta to generate a SSR build
- [swagger-typescript-api](https://github.com/acacode/swagger-typescript-api): Open source typescript api codegenerator from Swagger. Uses Eta as codegenerator by templates
- [html-bundler-webpack-plugin](https://github.com/webdiscus/html-bundler-webpack-plugin): Webpack plugin make easily to bundle HTML pages from templates, source styles and scripts
- [SmartDeno](https://github.com/guildenstern70/SmartDeno): SmartDeno is an easy to setup web template using Deno & Oak
- [stc](https://github.com/long-woo/stc): OpenAPI (Swagger) and Apifox documentation converted to api. Use eta templates to generate code.
- [Add yours!](https://github.com/bgub/eta/edit/master/README.md)
## Contributors
Made with ❤️ by [bgub](https://github.com/bgub) and [many wonderful contributors](https://github.com/bgub/eta/graphs/contributors). Contributions of any kind are welcome!
## Credits
- Async support, file handling, and error formatting were based on code from [EJS](https://github.com/mde/ejs), which is licensed under the Apache-2.0 license. Code was modified and refactored to some extent.
- Syntax and some parts of compilation are heavily based off EJS, Nunjucks, and doT.