# `PhoenixKit.Modules.Sitemap.DomainMode`
[🔗](https://github.com/BeamLabEU/phoenix_kit/blob/v2.13.7/lib/modules/sitemap/domain_mode.ex#L1)

Multi-domain sitemap post-processing (one domain = one canonical language).

Activated by a host-app provider:

    config :phoenix_kit, :sitemap_domains_provider, {MyAppWeb.SEO, :sitemap_domains}

The provider returns `[%{host: "example.fr", language: "fr", primary: false}, ...]`.
The result is VALIDATED here — exactly one `primary: true`, every host a
distinct language (base-code level), well-formed hosts. Any violation
deactivates domain mode (with a warning) rather than silently producing
malformed URLs or dropping x-default.

`rebuild_for_domains/2` regroups the entries the generator already
collected across languages: for the domain of language L, every canonical
group that HAS an L entry contributes one URL — L's own entry re-hosted on
that domain with its locale prefix stripped (L is the default there) —
carrying an alternates set computed ONCE per group (identical across all
domain files by construction): each group language on its home URL, plus
`x-default` for the primary domain's language when the group has it
(omitted otherwise — never mislabel another language as x-default).

An enabled language that has NO domain of its own keeps its locale prefix
and lives on the primary domain, so its URLs are published from the primary
domain's file (they are already what this module's alternates point at).
Mapped hosts stay strictly single-language.

Runs inside Oban jobs and unpiped controller requests: language resolution
here never consults the request-scoped default-language override — the
unprefixed-entry fallback reads the raw `is_default` flag, mirroring the
generator's hardened `get_languages/0`.

NB: the generator's `base_url` (Settings `site_url`) and the provider's
primary host are independently-edited settings that must refer to the same
site; rel-path extraction below is host-string-agnostic, so a mismatch
yields consistent (if unexpected-host) URLs rather than corruption.

# `domain`

```elixir
@type domain() :: %{host: String.t(), language: String.t(), primary: boolean()}
```

# `domains`

```elixir
@spec domains() :: [domain()]
```

Validated provider domains; [] (inactive) on any contract violation.

# `rebuild_for_domains`

```elixir
@spec rebuild_for_domains([PhoenixKit.Modules.Sitemap.UrlEntry.t()], String.t()) :: %{
  required(String.t()) => [PhoenixKit.Modules.Sitemap.UrlEntry.t()]
}
```

Regroups collected entries into per-domain URL sets: `%{host => [UrlEntry.t()]}`.

---

*Consult [api-reference.md](api-reference.md) for complete listing*