05-allowing-the-same-slug-for-translations.md

Allowing the same slug on different language versions

Often your translated documents will share the same slug. You might wish to move this into the metadata document itself using the metadataFields option in the plugin. Alternatively, you can customize the isUnique function on a slug type field.

// Add the isUnique option to your slug field
defineField({
  name: 'slug',
  type: 'slug',
  options: {
    isUnique: isUniqueOtherThanLanguage
  },
}),

// Create the function
// This checks that there are no other documents
// With this published or draft _id
// Or this schema type
// With the same slug and language
export async function isUniqueOtherThanLanguage(slug: string, context: SlugValidationContext) {
  const {document, getClient} = context
  if (!document?.language) {
    return true
  }
  const client = getClient({apiVersion: '2023-04-24'})
  const id = document._id.replace(/^drafts\./, '')
  const params = {
    draft: `drafts.${id}`,
    published: id,
    language: document.language,
    slug,
  }
  const query = `!defined(*[
    !(_id in [$draft, $published]) &&
    slug.current == $slug &&
    language == $language
  ][0]._id)`
  const result = await client.fetch(query, params)
  return result
}