# `Localize.Plug`
[🔗](https://github.com/elixir-localize/localize_web/blob/main/lib/localize/plug.ex#L1)

Utility functions for setting the locale from the session for Localize and Gettext.

The primary use case is in LiveView `on_mount` callbacks where the locale needs to be restored from the session that was set during the initial HTTP request by `Localize.Plug.PutLocale` and `Localize.Plug.PutSession`.

# `put_locale_from_session`

```elixir
@spec put_locale_from_session(
  map(),
  keyword()
) :: {:ok, Localize.LanguageTag.t()} | {:error, Exception.t()}
```

Puts the locale from the session into the current process.

Always sets the Localize process locale via `Localize.put_locale/1`. If Gettext backends are provided, the locale is also set on each backend.

This function is useful to place in the `on_mount` callback for a LiveView.

### Arguments

* `session` is any map, typically the map returned as part of the `conn` of a Phoenix or Plug request. A `session` is passed as the third parameter to the `on_mount` callback of a LiveView request.

* `options` is a keyword list of options.

### Options

* `:gettext` is a Gettext backend module or a list of Gettext backend modules on which the locale will be set. The default is `[]` (no Gettext backends).

### Returns

* `{:ok, locale}` or

* `{:error, {exception, reason}}`

### Examples

    iex> Localize.Plug.put_locale_from_session(session)
    iex> Localize.Plug.put_locale_from_session(session, gettext: MyApp.Gettext)
    iex> Localize.Plug.put_locale_from_session(session, gettext: [MyApp.Gettext, MyOtherApp.Gettext])

    # In a LiveView
    def on_mount(:default, _params, session, socket) do
      {:ok, locale} = Localize.Plug.put_locale_from_session(session, gettext: MyApp.Gettext)
      {:cont, socket}
    end

---

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