unihead

Fast and minimal JS <head> server-side writer and client-side manager.

Nearly every SSR framework out there relies on server-side components to update the <head>. This is the case for Next, Nuxt 2, Nuxt 3 and Remix. The problem with that approach is that the <head> becomes dependent on your entire component stack being server-side rendered first, or at least a big part of it, which is generally expensive and prevents you from streaming the <head> right away to the client.

unihead is a library conveniently packing both a server-side API, that lets you generate <head> elements programatically, and a client-side API that hydrates a data model from the rendered elements independently of the framework you’re using (all vanilla DOM manipulation) and lets you mutate it and also reset it to its original state (useful for managing <head> inbetween client-side route navigation).

Install

npm install unihead --save

Server usage

The server module of this package supports the adoption of an alternative pattern where all data required for rendering <head> elements is fetched prior to any framework-level component rendering, so it can be streamed to the client right away.

The server-side <head> cannot be mutated, it must be created only once from an object.

import Head from 'unihead'

const head = new Head({
  title: 'Page Title'
  meta: [
    { name: 'twitter:title', content: 'Page Title' }
  ],
})

There are two methods available: render(), which produces a full string with all rendered <head> elements.

const head = new Head({ ... }).render()
const html = `<head>${head}</head><body>...</body>`

And stream(), which returns a Readable Node.js stream (built from an Iterator) that yields one <head> element at a time.

See a full streaming example here.

Client usage

If you’re using a tool such as Vite to build your client application build, import the client module of the package and instantiate Head the same way it is done on the server.

A global registration distribution is also available, that lets you simply include unihead as the last script import of your <head> and have it globally available (and automatically instantiated) in the window object.

The client Head class will load the rendered <head> from the page internally in a data model and let you modify it or reset it to its orignal state if needed.

Import using a build tool

import Head from 'unihead/client'

const head = new Head()

Vanilla script include

<head>
  <!-- Head elements -->
  <script src="https://unpkg.com/unihead"></script>
</head>

In which case window.head is available immediately afterwards, automatically instantied from the Head class.

This option is provided for easily integrating unihead with any kind of vanilla HTML/JS application.

Mutation methods

The main difference between the server and client modules is that the latter allows you to mutate the data, i.e., change existing elements or add new ones if needed. API follows:

  • head.title=
  • head.base=
  • head.meta[].set()
  • head.link[].set()
  • head.meta[].push()
  • head.link[].push()

For standalone self-closing elements, use assignment:

head.title = 'Page title'
head.base = { href: 'https://...', target: '_blank' }

For collective self-closing elements, use set():

head.meta.set({ name: '...', content: '...' })

You can also use push(arr) to set multiple tags at once.

In the case of <meta> tags, name and property are used to uniquely identify tags and mutate them without having to add new ones if they already exist.

You can also remove collection items:

head.meta.remove({name: 'twitter:title'})

Finally, you can also fully reset any changes made:

head.reset()

Limitations

When compared to libraries like vueuse/head, which is integrated with a framework, you’ll notice unihead is missing a few features:

  • There’s no way to set <html> and <body> attributes.

  • There’s no way to create <script> tags with content, just attributes.

  • Similarly, there’s no way to create <style> tags.

unihead limits itself to either empty or self-closing elements under <head>.

GitHub

View Github