@fastify/view
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Template plugin for Fastify
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# @fastify/view
[](https://github.com/fastify/point-of-view/actions/workflows/ci.yml)
[](https://www.npmjs.com/package/@fastify/view)
[](https://github.com/neostandard/neostandard)
Templates rendering plugin support for Fastify.
`@fastify/view` decorates the reply interface with the `view` and `viewAsync` methods for managing view engines, which can be used to render templated responses.
Currently supports the following templates engines:
- [`ejs`](https://ejs.co/)
- [`nunjucks`](https://mozilla.github.io/nunjucks/)
- [`pug`](https://pugjs.org/api/getting-started.html)
- [`handlebars`](https://handlebarsjs.com/)
- [`mustache`](https://mustache.github.io/)
- [`twig`](https://twig.symfony.com/)
- [`liquid`](https://github.com/harttle/liquidjs)
- [`doT`](https://github.com/olado/doT)
- [`eta`](https://eta.js.org)
In `production` mode, `@fastify/view` will heavily cache the templates file and functions, while in `development` will reload every time the template file and function.
_Note: For **Fastify v3 support**, please use point-of-view `5.x` (npm i point-of-view@5)._
_Note that at least Fastify `v2.0.0` is needed._
## Recent Changes
_Note: `reply.viewAsync` added as a replacement for `reply.view` and `fastify.view`. See [Migrating from view to viewAsync](#migrating-from-view-to-viewAsync)._
_Note: [`ejs-mate`](https://github.com/JacksonTian/ejs-mate) support [has been dropped](https://github.com/fastify/point-of-view/pull/157)._
_Note: [`marko`](https://markojs.com/) support has been dropped. Please use [`@marko/fastify`](https://github.com/marko-js/fastify) instead._
#### Benchmarks
The benchmarks were run with the files in the `benchmark` folder with the `ejs` engine.
The data has been taken with: `autocannon -c 100 -d 5 -p 10 localhost:3000`
- Express: 8.8k req/sec
- **Fastify**: 15.6k req/sec
## Install
```
npm i @fastify/view
```
<a name="quickstart"></a>
## Quick start
`fastify.register` is used to register @fastify/view. By default, It will decorate the `reply` object with a `view` method that takes at least two arguments:
- the template to be rendered
- the data that should be available to the template during rendering
This example will render the template using the EJS engine and provide a variable `name` to be used inside the template:
```html
<!-- index.ejs --->
<!DOCTYPE html>
<html lang="en">
<head></head>
<body>
<p>Hello, <%= name %>!</p>
</body>
</html>
```
```js
// index.js:
const fastify = require("fastify")()
const fastifyView = require("@fastify/view")
fastify.register(fastifyView, {
engine: {
ejs: require("ejs")
}
})
// synchronous handler:
fastify.get("/", (req, reply) => {
reply.view("index.ejs", { name: "User" });
})
// asynchronous handler:
fastify.get("/", async (req, reply) => {
return reply.viewAsync("index.ejs", { name: "User" });
})
fastify.listen({ port: 3000 }, (err) => {
if (err) throw err;
console.log(`server listening on ${fastify.server.address().port}`);
})
```
## Configuration
### Options
| Option | Description | Default |
| ---------------------- | ----------- | ------- |
| `engine` | **Required**. The template engine object - pass in the return value of `require('<engine>')` | |
| `production` | Enables caching of template files and render functions | `NODE_ENV === "production"` |
| `maxCache` | In `production` mode, maximum number of cached template files and render functions | `100` |
| `defaultContext` | Template variables available to all views. Variables provided on render have precedence and will **override** this if they have the same name. <br><br>Example: `{ siteName: "MyAwesomeSite" }` | `{}` |
| `propertyName` | The property that should be used to decorate `reply` and `fastify` <br><br>E.g. `reply.view()` and `fastify.view()` where `"view"` is the property name | `"view"` |
| `asyncPropertyName` | The property that should be used to decorate `reply` for async handler <br><br>Defaults to `${propertyName}Async` if `propertyName` is defined | `"viewAsync"` |
| `root` | The root path of your templates folder. The template name or path passed to the render function will be resolved relative to this path | `"./"` |
| `charset` | Default charset used when setting `Content-Type` header | `"utf-8"` |
| `includeViewExtension` | Automatically append the default extension for the used template engine **if omitted from the template name**. So instead of `template.hbs`, just `template` can be used | `false` |
| `viewExt` | Override the default extension for a given template engine. This has precedence over `includeViewExtension` and will lead to the same behavior, just with a custom extension. <br><br>Example: `"handlebars"` | `""` |
| `layout` | See [Layouts](#layouts) <br><br>This option lets you specify a global layout file to be used when rendering your templates. Settings like `root` or `viewExt` apply as for any other template file. <br><br>Example: `./templates/layouts/main.hbs` | |
| `options` | See [Engine-specific settings](#engine-specific-settings) | `{}` |
### Example
```js
fastify.register(require("@fastify/view"), {
engine: {
handlebars: require("handlebars"),
},
root: path.join(__dirname, "views"), // Points to `./views` relative to the current file
layout: "./templates/template", // Sets the layout to use to `./views/templates/layout.handlebars` relative to the current file.
viewExt: "handlebars", // Sets the default extension to `.handlebars`
propertyName: "render", // The template can now be rendered via `reply.render()` and `fastify.render()`
defaultContext: {
dev: process.env.NODE_ENV === "development", // Inside your templates, `dev` will be `true` if the expression evaluates to true
},
options: {}, // No options passed to handlebars
});
```
## Layouts
@fastify/view supports layouts for **EJS**, **Handlebars**, **Eta** and **doT**. When a layout is specified, the request template is first rendered, then the layout template is rendered with the request-rendered html set on `body`.
### Example
```html
<!-- layout.ejs: -->
<!DOCTYPE html>
<html lang="en">
<head></head>
<body>
<!--
Ensure body is not escaped:
EJS: <%- body %>
Handlebars: {{{ body }}}
ETA/doT: <%~ it.body %>
-->
<%- body %>
<br/>
</body>
</html>
```
```html
<!-- template.ejs: -->
<p><%= text %></p>
```
```js
// index.js:
fastify.register(fastifyView, {
engine: { ejs },
layout: "layout.ejs"
})
fastify.get('/', (req, reply) => {
const data = { text: "Hello!"}
reply.view('template.ejs', data)
})
```
### Providing a layout on render
**Please note:** Global layouts and providing layouts on render are mutually exclusive. They can not be mixed.
```js
fastify.get('/', (req, reply) => {
const data = { text: "Hello!"}
reply.view('template.ejs', data, { layout: 'layout.ejs' })
})
```
## Setting request-global variables
Sometimes, several templates should have access to the same request-specific variables. E.g. when setting the current username.
If you want to provide data, which will be depended on by a request and available in all views, you have to add property `locals` to `reply` object, like in the example below:
```js
fastify.addHook("preHandler", function (request, reply, done) {
reply.locals = {
text: getTextFromRequest(request), // it will be available in all views
};
done();
});
```
Properties from `reply.locals` will override those from `defaultContext`, but not from `data` parameter provided to `reply.view(template, data)` function.
## Rendering the template into a variable
The `fastify` object is decorated the same way as `reply` and allows you to just render a view into a variable (without request-global variables) instead of sending the result back to the browser:
```js
// Promise based, using async/await
const html = await fastify.view("/templates/index.ejs", { text: "text" });
// Callback based
fastify.view("/templates/index.ejs", { text: "text" }, (err, html) => {
// Handle error
// Do something with `html`
});
```
If called within a request hook and you need request-global variables, see [Migrating from view to viewAsync](#migrating-from-view-to-viewAsync).
## Registering multiple engines
Registering multiple engines with different configurations is supported. They are distinguished via their `propertyName`:
```js
fastify.register(require("@fastify/view"), {
engine: { ejs: ejs },
layout: "./templates/layout-mobile.ejs",
propertyName: "mobile",
});
fastify.register(require("@fastify/view"), {
engine: { ejs: ejs },
layout: "./templates/layout-desktop.ejs",
propertyName: "desktop",
});
fastify.get("/mobile", (req, reply) => {
// Render using the `mobile` render function
return reply.mobile("/templates/index.ejs", { text: "text" });
});
fastify.get("/desktop", (req, reply) => {
// Render using the `desktop` render function
return reply.desktop("/templates/index.ejs", { text: "text" });
});
```
## Minifying HTML on render
To utilize [`html-minifier-terser`](https://www.npmjs.com/package/html-minifier-terser) in the rendering process, you can add the option `useHtmlMinifier` with a reference to `html-minifier-terser`,
and the optional `htmlMinifierOptions` option is used to specify the `html-minifier-terser` options:
```js
// get a reference to html-minifier-terser
const minifier = require('html-minifier-terser')
// optionally defined the html-minifier-terser options
const minifierOpts = {
removeComments: true,
removeCommentsFromCDATA: true,
collapseWhitespace: true,
collapseBooleanAttributes: true,
removeAttributeQuotes: true,
removeEmptyAttributes: true
}
// in template engine options configure the use of html-minifier
options: {
useHtmlMinifier: minifier,
htmlMinifierOptions: minifierOpts
}
```
To exclude paths from minification, you can add the option `pathsToExcludeHtmlMinifier` with a list of paths:
```js
// get a reference to html-minifier-terser
const minifier = require('html-minifier-terser')
// in options configure the use of html-minifier-terser and set paths to exclude from minification
const options = {
useHtmlMinifier: minifier,
pathsToExcludeHtmlMinifier: ['/test']
}
fastify.register(require("@fastify/view"), {
engine: {
ejs: require('ejs')
},
options
});
// This path is excluded from minification
fastify.get("/test", (req, reply) => {
reply.view("./template/index.ejs", { text: "text" });
});
```
## Engine-specific settings
<!---
// I don't think this is needed - see https://github.com/fastify/point-of-view/issues/280
## EJS
To use include files please extend your template options as follows:
```js
// get a reference to resolve
const resolve = require('node:path').resolve;
// other code ...
// in template engine options configure how to resolve templates folder
options: {
filename: resolve("templates");
}
```
and in ejs template files (for example templates/index.ejs) use something like:
```html
<%- include('header.ejs') %>
```
with a path relative to the current page, or an absolute path. Please check this example [here](./templates/layout-with-includes.ejs)
--->
### Mustache
To use partials in mustache you will need to pass the names and paths in the options parameter:
```js
options: {
partials: {
header: 'header.mustache',
footer: 'footer.mustache'
}
}
```
```js
fastify.get('/', (req, reply) => {
reply.view('./templates/index.mustache', data)
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.mustache', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
const render = mustache.render.bind(mustache, file)
reply.view(render, data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.mustache', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### Handlebars
To use partials in handlebars you will need to pass the names and paths in the options parameter:
```js
options: {
partials: {
header: 'header.hbs',
footer: 'footer.hbs'
}
}
```
You can specify [compile options](https://handlebarsjs.com/api-reference/compilation.html#handlebars-compile-template-options) as well:
```js
options: {
compileOptions: {
preventIndent: true
}
}
```
To access `defaultContext` and `reply.locals` as [`@data` variables](https://handlebarsjs.com/api-reference/data-variables.html):
```js
options: {
useDataVariables: true
}
```
To use layouts in handlebars you will need to pass the `layout` parameter:
```js
fastify.register(require("@fastify/view"), {
engine: {
handlebars: require("handlebars"),
},
layout: "./templates/layout.hbs",
});
fastify.get("/", (req, reply) => {
reply.view("./templates/index.hbs", { text: "text" });
});
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.hbs', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
const render = handlebars.compile(file)
reply.view(render, data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.hbs', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### Nunjucks
You can load templates from multiple paths when using the nunjucks engine:
```js
fastify.register(require("@fastify/view"), {
engine: {
nunjucks: require("nunjucks"),
},
templates: [
"node_modules/shared-components",
"views",
],
});
```
To configure nunjucks environment after initialization, you can pass callback function to options:
```js
options: {
onConfigure: (env) => {
// do whatever you want on nunjucks env
};
}
```
```js
fastify.get('/', (req, reply) => {
reply.view('./templates/index.njk', data)
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.njk', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
const render = nunjucks.compile(file)
reply.view(render, data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.njk', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### Liquid
To configure liquid you need to pass the engine instance as engine option:
```js
const { Liquid } = require("liquidjs");
const path = require('node:path');
const engine = new Liquid({
root: path.join(__dirname, "templates"),
extname: ".liquid",
});
fastify.register(require("@fastify/view"), {
engine: {
liquid: engine,
},
});
fastify.get("/", (req, reply) => {
reply.view("./templates/index.liquid", { text: "text" });
});
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.liquid', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
const render = engine.renderFile.bind(engine, './templates/index.liquid')
reply.view(render, data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.liquid', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### doT
When using [doT](https://github.com/olado/doT) the plugin compiles all templates when the application starts, this way all `.def` files are loaded and
both `.jst` and `.dot` files are loaded as in-memory functions.
This behavior is recommended by the doT team [here](https://github.com/olado/doT#security-considerations).
To make it possible it is necessary to provide a `root` or `templates` option with the path to the template directory.
```js
fastify.register(require("@fastify/view"), {
engine: {
dot: require("dot"),
},
root: "templates",
options: {
destination: "dot-compiled", // path where compiled .jst files are placed (default = 'out')
},
});
fastify.get("/", (req, reply) => {
// this works both for .jst and .dot files
reply.view("index", { text: "text" });
});
```
```js
const d = dot.process({ path: 'templates', destination: 'out' })
fastify.get('/', (req, reply) => {
reply.view(d.index, data)
})
```
```js
fastify.get('/', (req, reply) => {
reply.view({ raw: readFileSync('./templates/index.dot'), imports: { def: readFileSync('./templates/index.def') } }, data)
})
```
### eta
```js
const { Eta } = require('eta')
let eta = new Eta()
fastify.register(pointOfView, {
engine: {
eta
},
templates: 'templates'
})
fastify.get("/", (req, reply) => {
reply.view("index.eta", { text: "text" });
});
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.eta', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view(eta.compile(file), data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.eta', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### ejs
```js
const ejs = require('ejs')
fastify.register(pointOfView, {
engine: {
ejs
},
templates: 'templates'
})
fastify.get("/", (req, reply) => {
reply.view("index.ejs", { text: "text" });
});
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.ejs', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view(ejs.compile(file), data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.ejs', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### pug
```js
const pug = require('pug')
fastify.register(pointOfView, {
engine: {
pug
}
})
fastify.get("/", (req, reply) => {
reply.view("index.pug", { text: "text" });
});
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.pug', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view(pug.compile(file), data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.pug', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
### twig
```js
const twig = require('twig')
fastify.register(pointOfView, {
engine: {
twig
}
})
fastify.get("/", (req, reply) => {
reply.view("index.twig", { text: "text" });
});
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.twig', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view(twig.twig({ data: file }), data)
}
})
})
```
```js
fastify.get('/', (req, reply) => {
fs.readFile('./templates/index.twig', 'utf8', (err, file) => {
if (err) {
reply.send(err)
} else {
reply.view({ raw: file }, data)
}
})
})
```
<!---
// This seems a bit random given that there was no mention of typescript before.
### Typing
Typing parameters from `reply.locals` in `typescript`:
```typescript
interface Locals {
appVersion: string;
isAuthorized: boolean;
user?: {
id: number;
login: string;
};
}
declare module "fastify" {
interface FastifyReply {
locals: Partial<Locals> | undefined;
}
}
app.addHook("onRequest", (request, reply, done) => {
if (!reply.locals) {
reply.locals = {};
}
reply.locals.isAuthorized = true;
reply.locals.user = {
id: 1,
login: "Admin",
};
});
app.get("/data", (request, reply) => {
if (!reply.locals) {
reply.locals = {};
}
// reply.locals.appVersion = 1 // not a valid type
reply.locals.appVersion = "4.14.0";
reply.view<{ text: string }>("/index", { text: "Sample data" });
});
```
-->
## Miscellaneous
### Using @fastify/view as a dependency in a fastify-plugin
To require `@fastify/view` as a dependency to a [fastify-plugin](https://github.com/fastify/fastify-plugin), add the name `@fastify/view` to the dependencies array in the [plugin's opts](https://github.com/fastify/fastify-plugin#dependencies).
```js
fastify.register(myViewRendererPlugin, {
dependencies: ["@fastify/view"],
});
```
### Forcing a cache-flush
To forcefully clear the cache when in production mode, call the `view.clearCache()` function.
```js
fastify.view.clearCache();
```
<a name="note"></a>
### Migrating from `view` to `viewAsync`
The behavior of `reply.view` is to immediately send the HTML response as soon as rendering is completed, or immediately send a 500 response with error if encountered, short-circuiting fastify's error handling hooks, whereas `reply.viewAsync` returns a promise that either resolves to the rendered HTML, or rejects on any errors. `fastify.view` has no mechanism for providing request-global variables, if needed. `reply.viewAsync` can be used in both sync and async handlers.
#### Sync handler
Previously:
```js
fastify.get('/', (req, reply) => {
reply.view('index.ejs', { text: 'text' })
})
```
Now:
```js
fastify.get('/', (req, reply) => {
return reply.viewAsync('index.ejs', { text: 'text' })
})
```
#### Async handler
Previously:
```js
// This is an async function
fastify.get("/", async (req, reply) => {
const data = await something();
reply.view("/templates/index.ejs", { data });
return
})
```
Now:
```js
// This is an async function
fastify.get("/", async (req, reply) => {
const data = await something();
return reply.viewAsync("/templates/index.ejs", { data });
})
```
#### fastify.view (when called inside a route hook)
Previously:
```js
// Promise based, using async/await
fastify.get("/", async (req, reply) => {
const html = await fastify.view("/templates/index.ejs", { text: "text" });
return html
})
```
```js
// Callback based
fastify.get("/", (req, reply) => {
fastify.view("/templates/index.ejs", { text: "text" }, (err, html) => {
if(err) {
reply.send(err)
}
else {
reply.type("application/html").send(html)
}
});
})
```
Now:
```js
// Promise based, using async/await
fastify.get("/", (req, reply) => {
const html = await fastify.viewAsync("/templates/index.ejs", { text: "text" });
return html
})
```
```js
fastify.get("/", (req, reply) => {
fastify.viewAsync("/templates/index.ejs", { text: "text" })
.then((html) => reply.type("application/html").send(html))
.catch((err) => reply.send(err))
});
})
```
## Note
By default, views are served with the mime type `text/html`, with the charset specified in options. You can specify a different `Content-Type` header using `reply.type`.
## Acknowledgments
This project is kindly sponsored by:
- [nearForm](https://nearform.com)
- [LetzDoIt](https://www.letzdoitapp.com/)
## License
Licensed under [MIT](./LICENSE).