# `PhoenixKitWeb.Components.Core.LanguageSwitcher`
[🔗](https://github.com/BeamLabEU/phoenix_kit/blob/v1.7.164/lib/phoenix_kit_web/components/core/language_switcher.ex#L1)

Language switcher component for frontend and admin applications.

Provides reusable language selection UI that pulls available languages
from the unified Languages module. Three display variants are available:
dropdown, button group, and inline.

## Continent Grouping

When more than 7 languages are enabled (configurable via `continent_threshold`),
the dropdown automatically shows a two-step interface: first pick a continent,
then pick a language within it. Set `group_by_continent={false}` to always
show a flat list regardless of language count.

## Examples

    # Basic dropdown — auto-groups by continent when >7 languages
    <.language_switcher_dropdown current_locale={@current_locale} />

    # Force flat list (no continent step)
    <.language_switcher_dropdown current_locale={@current_locale} group_by_continent={false} />

    # Custom threshold for continent grouping
    <.language_switcher_dropdown current_locale={@current_locale} continent_threshold={5} />

    # Show current language in trigger button
    <.language_switcher_dropdown current_locale={@current_locale} show_current={true} />

    # Button group (for mobile)
    <.language_switcher_buttons current_locale={@current_locale} />

    # Inline text links (for footers)
    <.language_switcher_inline current_locale={@current_locale} />

# `dedupe_names`

Overrides each language entry's `:name` (or `"name"`) with the
bare base-language label when only one dialect of that base is
configured. Multi-dialect bases keep their full configured name so
users can tell them apart.

Accepts a list of language entries shaped as atom-keyed maps,
string-keyed maps, or `%PhoenixKit.Modules.Languages.Language{}`
structs. Returns the list in the same shape with the relevant
`:name`/`"name"` key replaced.

Used by the admin top-bar dropdown and the user dashboard nav to
inherit the frontend switcher's dedup rule without duplicating the
logic. Internal frontend-switcher code paths
(`build_dialect_list/1`, `langs_to_dialect_maps/2`) compute names
inline because they emit a new result map per entry; this helper
is the entry point for callers that already have a list of entries
and just need their names normalized.

# `extract_base_language_name`

Strips the country / region qualifier from a configured language
name. Used to render bare base-language labels when only one
dialect of the base is enabled.

Public because the admin top-bar dropdown
(`PhoenixKitWeb.Components.AdminNav`) and the user dashboard nav
(`PhoenixKitWeb.Components.UserDashboardNav`) both call into it via
`dedupe_names/1` so all language menus share one rule.

## Examples

    iex> extract_base_language_name("Spanish (Mexico)")
    "Spanish"

    iex> extract_base_language_name("Chinese (Simplified)")
    "Chinese"

    iex> extract_base_language_name("Japanese")
    "Japanese"

# `language_switcher_buttons`

Renders a button group language switcher.

Displays language buttons in a row. Good for mobile layouts and areas
where space allows for multiple buttons. Automatically fetches the configured
languages (or default top 12 if not configured).

## Examples

    <.language_switcher_buttons current_locale={@current_locale} />

## Attributes

* `current_locale` (`:string`) - Current active language code (auto-detected if not provided). Defaults to `nil`.
* `languages` (`:any`) - List of language maps. If nil, fetches from Language Module. Defaults to `nil`.
* `show_flags` (`:boolean`) - Show language flags. Defaults to `true`.
* `show_names` (`:boolean`) - Show language names. Defaults to `true`.
* `goto_home` (`:boolean`) - Redirect to home page on language switch. Defaults to `false`.
* `hide_current` (`:boolean`) - Hide currently selected language from list. Defaults to `false`.
* `class` (`:string`) - Additional CSS classes. Defaults to `""`.
* `current_path` (`:string`) - Current path to preserve when switching languages. Defaults to `nil`.
* `per_translation_urls` (`:list`) - Optional per-translation URL overrides. See `language_switcher_dropdown/1` for details. Defaults to `nil`.

# `language_switcher_dropdown`

Renders a dropdown language switcher.

Displays a globe icon that opens a dropdown menu with available languages.
Automatically fetches the configured languages (or defaults when unconfigured).
Used in both frontend navigation bars and the admin panel header.

When more than `continent_threshold` languages are enabled, shows a two-step
continent → language navigation. Set `group_by_continent={false}` to disable.

## Examples

    <.language_switcher_dropdown current_locale={@current_locale} />

    <.language_switcher_dropdown
      current_locale={@current_locale}
      group_by_continent={false}
    />

## Attributes

* `current_locale` (`:string`) - Current active language code (auto-detected if not provided). Defaults to `nil`.
* `languages` (`:any`) - List of language maps. If nil, fetches from Language Module. Defaults to `nil`.
* `show_flags` (`:boolean`) - Show language flags. Defaults to `true`.
* `show_names` (`:boolean`) - Show language names. Defaults to `true`.
* `show_native_names` (`:boolean`) - Show native language names. Defaults to `false`.
* `goto_home` (`:boolean`) - Redirect to home page on language switch. Defaults to `false`.
* `hide_current` (`:boolean`) - Hide currently selected language from list. Defaults to `false`.
* `class` (`:string`) - Additional CSS classes. Defaults to `""`.
* `current_path` (`:string`) - Current path to preserve when switching languages. Defaults to `nil`.
* `scroll_threshold` (`:integer`) - Number of languages after which to show scrollbar and search. Defaults to `10`.
* `show_current` (`:boolean`) - Show current language (flag + name) in dropdown trigger instead of globe icon. Defaults to `false`.
* `group_by_continent` (`:boolean`) - Enable continent grouping when language count exceeds continent_threshold. Defaults to `true`.
* `continent_threshold` (`:integer`) - Number of languages after which the continent grouping step is shown. Defaults to `7`.
* `_language_update_key` (`:any`) - Internal: forces re-render when languages change. Defaults to `nil`.
* `per_translation_urls` (`:list`) - Optional list of per-translation URLs that override the locale-rewrite
  default. Each entry is `%{code: <display_code>, url: <full_url>}`.
  Both atom-keyed (`%{code: ..., url: ...}`) and string-keyed
  (`%{"code" => ..., "url" => ...}`) entries are accepted — useful
  when the list comes from JSON/JSONB rather than Elixir code.

  Useful when a feature module (e.g. `phoenix_kit_publishing`) has
  computed canonical URLs for each available translation that the
  simple locale-rewrite default can't reproduce — for example when
  a post has per-language URL slugs. Pass
  `assigns[:phoenix_kit_publishing_translations]` from the layout;
  the switcher resolves each language's `base_code` against the list
  (via `DialectMapper.extract_base/1`) and falls back to the
  locale-rewrite URL when no entry matches or the matched entry
  has a `nil` `url` (e.g. an unpublished draft).

  Defaults to `nil`.
* `ai_translate` (`:map`) - Optional opt-in for the AI-translate affordance. When present and
  `:enabled` is true, missing-language items show a sparkle button
  that fires the host LV's `phx-click` event (and a bulk
  "translate all missing" CTA renders below the list when ≥2 languages
  are missing).

  Shape:

      %{
        enabled: true,
        event: "translate_lang",        # phx-click target on host LV
        missing: ["es", "de"],          # base codes lacking a translation
        in_flight: ["es"]               # show spinner, click disabled
      }

  Only `:missing` and `:in_flight` drive rendering. A "completed"
  language is signalled simply by the host dropping its code from
  `:missing` — the sparkle then disappears on the next render. (There
  is no separate `:completed` checkmark state; pass nothing for it.)

  The component emits the host's event; the host owns enqueuing the
  actual translation worker and broadcasting the resulting `:missing` /
  `:in_flight` state back via PubSub. Set `:enabled` to `false` (or pass
  `nil`) to fall back to today's behavior with no AI UI — convenient for
  hosts that gate on `PhoenixKitAI.Translations.available?/0`.

  ## Bulk action dispatch

  The "Translate all missing" CTA fires the same event with
  `phx-value-lang="*"` as a sentinel. Host handlers branch on the
  value:

      def handle_event("translate_lang", %{"lang" => "*"}, socket) do
        # enqueue one job per *actionable* language (missing minus
        # in_flight) — matches the count shown on the bulk button
      end

      def handle_event("translate_lang", %{"lang" => lang}, socket) do
        # enqueue a single-language job
      end

  Defaults to `nil`.

# `language_switcher_inline`

Renders an inline language switcher.

Displays languages as inline text links. Minimal design perfect for footers
or compact navigation areas. Automatically fetches the configured languages
(or default top 12 if not configured).

## Examples

    <.language_switcher_inline current_locale={@current_locale} />

## Attributes

* `current_locale` (`:string`) - Current active language code (auto-detected if not provided). Defaults to `nil`.
* `languages` (`:any`) - List of language maps. If nil, fetches from Language Module. Defaults to `nil`.
* `show_flags` (`:boolean`) - Show language flags. Defaults to `true`.
* `show_names` (`:boolean`) - Show language names. Defaults to `true`.
* `goto_home` (`:boolean`) - Redirect to home page on language switch. Defaults to `false`.
* `hide_current` (`:boolean`) - Hide currently selected language from list. Defaults to `false`.
* `class` (`:string`) - Additional CSS classes. Defaults to `""`.
* `current_path` (`:string`) - Current path to preserve when switching languages. Defaults to `nil`.
* `per_translation_urls` (`:list`) - Optional per-translation URL overrides. See `language_switcher_dropdown/1` for details. Defaults to `nil`.

---

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