Merge pull request #189 from Baptistemontan/resolve_locale_fn

Function to resolve the locale without a context

docs/book/src/SUMMARY.md

@@ -27,6 +27,7 @@
   - [`t_format!`](./usage/09_t_format.md)
   - [`t_plural!`](./usage/10_t_plural.md)
   - [Constant Access](./usage/11_const_access.md)
+  - [Server functions](./usage/12_serverfn.md)
 - [More Informations](./infos/README.md)
   - [Locale Resolution](./infos/01_locale_resol.md)
 - [Reduce Binary Size](./reduce_size/README.md)

docs/book/src/usage/12_serverfn.md

@@ -0,0 +1,12 @@
+# Server functions
+
+There is no context in server functions, so you can't call `use_i18n`. You could provide a context if you want,
+and it would work as expected, but if you just want to access what locale the user is using you can use the `resolve_locale` function:
+
+```rust
+#[server]
+async fn get_locale() -> Result<Locale, ServerFnError> {
+    let locale: Locale = leptos_i18n::locale::resolve_locale();
+    Ok(locale)
+}
+```

leptos_i18n/src/context.rs

@@ -121,7 +121,7 @@ pub type CookieOptions<L> = UseCookieOptions<
     <FromToStringCodec as codee::Decoder<L>>::Error,
 >;
 
-const ENABLE_COOKIE: bool = cfg!(feature = "cookie");
+pub(crate) const ENABLE_COOKIE: bool = cfg!(feature = "cookie");
 
 const COOKIE_PREFERED_LANG: &str = "i18n_pref_locale";
 
@@ -167,14 +167,14 @@ where
     L: Locale,
 {
     /// Should set a cookie to keep track of the locale when page reload (default to true) (do nothing without the "cookie" feature)
-    enable_cookie: bool,
+    pub enable_cookie: bool,
     /// Give a custom name to the cookie (default to the crate default value) (do nothing without the "cookie" feature or if `enable_cookie` is false)
     #[builder(into)]
-    cookie_name: Cow<'a, str>,
+    pub cookie_name: Cow<'a, str>,
     /// Options for the cookie, the value is of type `leptos_use::UseCookieOptions<Locale>` (default to `Default::default`)
-    cookie_options: CookieOptions<L>,
+    pub cookie_options: CookieOptions<L>,
     /// Options to pass to `leptos_use::use_locales`.
-    ssr_lang_header_getter: UseLocalesOptions,
+    pub ssr_lang_header_getter: UseLocalesOptions,
 }
 
 impl<L: Locale> Default for I18nContextOptions<'_, L> {
@@ -209,6 +209,7 @@ pub fn init_i18n_context_with_options<L: Locale>(options: I18nContextOptions<L>)
 
     init_context_inner::<L>(set_lang_cookie, initial_locale)
 }
+
 /// Initialize a `I18nContext` without providing it.
 #[track_caller]
 pub fn init_i18n_context<L: Locale>() -> I18nContext<L> {

leptos_i18n/src/fetch_locale.rs

@@ -17,6 +17,19 @@ pub fn fetch_locale<L: Locale>(current_cookie: Option<L>, options: UseLocalesOpt
     }
 }
 
+pub fn get_accepted_locale<L: Locale>(options: UseLocalesOptions) -> L {
+    leptos_use::use_locales_with_options(options)
+        .with_untracked(|accepted| L::find_locale(accepted))
+}
+
+pub fn resolve_locale<L: Locale>(current_cookie: Option<L>, options: UseLocalesOptions) -> L {
+    cfg!(feature = "hydrate")
+        .then(get_locale_from_html)
+        .flatten()
+        .or(current_cookie)
+        .unwrap_or_else(move || get_accepted_locale(options))
+}
+
 pub fn signal_once_then<T: Clone + PartialEq + Send + Sync + 'static>(
     start: T,
     then: Memo<T>,
@@ -46,9 +59,8 @@ fn fetch_locale_ssr<L: Locale>(current_cookie: Option<L>, accepted_locale: Memo<
     signal_maybe_once_then(current_cookie, accepted_locale)
 }
 
-// hydrate fetch
-fn fetch_locale_hydrate<L: Locale>(current_cookie: Option<L>, accepted_locale: Memo<L>) -> Memo<L> {
-    let base_locale = leptos::prelude::document()
+fn get_locale_from_html<L: Locale>() -> Option<L> {
+    leptos::prelude::document()
         .document_element()
         .and_then(|el| match el.get_attribute("lang") {
             None => {
@@ -58,7 +70,11 @@ fn fetch_locale_hydrate<L: Locale>(current_cookie: Option<L>, accepted_locale: M
             Some(lang) => Some(lang),
         })
         .and_then(|lang| L::from_str(&lang).ok())
-        .or(current_cookie);
+}
+
+// hydrate fetch
+fn fetch_locale_hydrate<L: Locale>(current_cookie: Option<L>, accepted_locale: Memo<L>) -> Memo<L> {
+    let base_locale = get_locale_from_html().or(current_cookie);
 
     signal_maybe_once_then(base_locale, accepted_locale)
 }

leptos_i18n/src/lib.rs

@@ -125,17 +125,16 @@
 //! ```
 
 pub mod context;
+pub mod display;
 mod fetch_locale;
 mod fetch_translations;
 mod langid;
+pub mod locale;
 mod locale_traits;
 mod macro_helpers;
 mod macros;
-// mod routing;
 mod scopes;
 
-pub mod display;
-
 pub use macro_helpers::formatting;
 
 pub use locale_traits::{Direction, Locale, LocaleKeys};
@@ -162,7 +161,6 @@ pub mod __private {
     pub mod fetch_translations {
         pub use crate::fetch_translations::*;
     }
-    // pub use crate::fetch_locale::get_locale_from_path_inner;
     #[cfg(feature = "plurals")]
     pub use crate::formatting::get_plural_rules;
     pub use crate::macro_helpers::*;

leptos_i18n/src/locale.rs

@@ -0,0 +1,44 @@
+//! Contain utilities for locales
+
+use codee::string::FromToStringCodec;
+use leptos::prelude::*;
+
+use crate::{
+    context::{I18nContextOptions, ENABLE_COOKIE},
+    fetch_locale, Locale,
+};
+
+/// Same as `resolve_locale` but with some cookies options.
+pub fn resolve_locale_with_options<L: Locale>(options: I18nContextOptions<L>) -> L {
+    let I18nContextOptions {
+        enable_cookie,
+        cookie_name,
+        cookie_options,
+        ssr_lang_header_getter,
+    } = options;
+    let (lang_cookie, _) = if ENABLE_COOKIE && enable_cookie {
+        leptos_use::use_cookie_with_options::<L, FromToStringCodec>(&cookie_name, cookie_options)
+    } else {
+        let (lang_cookie, set_lang_cookie) = signal(None);
+        (lang_cookie.into(), set_lang_cookie)
+    };
+    fetch_locale::resolve_locale(lang_cookie.get_untracked(), ssr_lang_header_getter)
+}
+
+/// Resolve the locale.
+///
+/// This as the same behavior as calling `init_i18n_context().get_locale_untracked()`.
+///
+/// This function primary usage is to access a user locale in a server function, but is not constrained to it.
+///
+/// Here is the list of detection methods, sorted in priorities:
+/// 1. The "lang" attribute is set on the `<html>` element in hydrate
+/// 1. A cookie is present that contains a previously detected locale
+/// 1. A locale can be matched based on the [`Accept-Language` header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Language) in SSR
+/// 1. A locale can be matched based on the [`navigator.languages` API](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/languages) in CSR
+/// 1. As a last resort, the default locale is used.
+///
+/// *note*: this function does not take into account URL locale prefix when using `I18nRoute` (e.g. `/en/about`)
+pub fn resolve_locale<L: Locale>() -> L {
+    resolve_locale_with_options(Default::default())
+}