fix: avoid using shared global state for head

[wattanx]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

If you use UnheadPlugin, you need to add unhead to $options.
If useHead is used without being added, a vue warn will be thrown.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[harlan-zw]

Thanks for updating it, though in what context is this thrown?

UnheadPlugin from @unhead/vue causes [Vue warn]: injection "usehead" not found., so fixed for Nuxt 2.

There's probably a better fix than copying over the plugin code.

[wattanx]

@harlan-zw
Thanks ❤️

If you use UnheadPlugin, you need to add unhead to $options.
If useHead is used without being added, a vue warn will be thrown.

https://github.com/unjs/unhead/blob/53e63ca42d8311e9690513aab8f6cff0d067b2df/packages/vue/src/vue2/index.ts#L39-L53

I tried to think of a way to add unhead to $options in the case of Nuxt, but couldn't come up with a good way.

[harlan-zw]

Hi @wattanx, sorry I couldn't get this code pushed up for your talk!

I've pushed up some changes that fix the warnings being emitted which I think is the underlying issue you may have been trying to solve? For now, I think Nuxt 2 should use the deprecated plugin as the new one has some issues within Bridge.

Would you mind reviewing and making sure I've understood correctly?

[wattanx]

No worries!

Your fixes have solved the problem I was hoping to solve!
Thank you so much ❤️