FAQs

How to get LanguageIdentifier if not installed?

#![allow(unused)]
fn main() {
use fluent_templates::LanguageIdentifier;
}

Tip

fluent-templates also depends externally on fluent-bundle whichs provides utilities for parsing the Fluent syntax.

How to get the i18n context at initialization?

#![allow(unused)]
fn main() {
use leptos_fluent::leptos_fluent;

let i18n = leptos_fluent! {{
    // ...
}};

leptos::logging::log!("i18n context: {i18n:?}");
}

Use an expression to set the cookie attributes and will not be validated.

#![allow(unused)]
fn main() {
let attrs = "SameSite=Strict; MyCustomAttr=MyCustomValue;";
leptos_fluent! {{
    cookie_attrs: attrs,
    // ...
}}
}

How to get the fallback language

From fluent-templates v0.9.5 onwards can be obtained from your translations.

#![allow(unused)]
fn main() {
let fallback_language = expect_i18n().translations.get()[0].fallback();
}

Why examples don't use <For/> component?

Bug

There are some cases in which the <For/> component is not reproducible between SSR and hydrate modes leading to different renders, so decided to use a simple vector to not bring confusion to main examples.

In any case, the <For/> component is secure on CSR contexts and leptos_fluent::Languages implement Hash and Eq traits to be able to be passed directly to keys properties trigerring reactivity depending on the current active language.

#![allow(unused)]
fn main() {
use leptos_fluent::{i18n, Language};

leptos::logging::warn!("[WARNING]: Not secure on SSR");
view! {
    <p>{move_tr!("select-a-language")}</p>
    <For
        each=move || i18n().languages
        key=|lang| *lang
        children=move |lang| render_language(lang)
    />
}

fn render_language(lang: &'static Language) -> impl IntoView { ... }
}

How to manage translations on server actions

The translations reside on the client side, so the I18n can not be accessed as context on server actions. Pass the translations as values if the bandwidth is not a problem or use your own statics on server side.

#![allow(unused)]
fn main() {
use leptos::*;
use leptos_fluent::{tr, Language};

/// Server action showing client-side translated message on console
#[server(ShowHelloWorld, "/api")]
pub async fn show_hello_world(
    translated_hello_world: String,
    language: String,
) -> Result<(), ServerFnError> {
    println!("{translated_hello_world} ({language})");
    Ok(())
}

fn render_language(lang: &'static Language) -> impl IntoView {
    // Call on click to server action with a client-side translated
    // "hello-world" message
    let on_click = move |_| {
        lang.activate();
        spawn_local(async {
            _ = show_hello_world(
                tr!("hello-world"),
                lang.name.to_string(),
            ).await;
        });
    };

    view! {
        <div>
            <label for=lang>{lang.name}</label>
            <input
                id=lang
                name="language"
                value=lang
                checked=lang.is_active()
                on:click=on_click
                type="radio"
            />
        </div>
    }
}
}

How to change <html> attributes on SSR

Use the component leptos_fluent::SsrHtmlTag:

#![allow(unused)]
fn main() {
use leptos::*;
use leptos_fluent::{leptos_fluent, SsrHtmlTag};

#[component]
pub fn App() -> impl IntoView {
    leptos_fluent! {{
        // ...
    }};

    view! {
        <SsrHtmlTag/>
        <LanguageSelector/>
    }
}

#[component]
fn LanguageSelector() -> impl IntoView { ... }
}

How to get values of leptos_fluent! macro at runtime?

Use provide_meta_context at the macro initialization and get them with the method I18n::meta:

#![allow(unused)]
fn main() {
let i18n = leptos_fluent! {{
    // ...
    provide_meta_context: true,
}};

println!("Macro parameters: {:?}", i18n.meta().unwrap());
}

Different configuration conditional checks

leptos_fluent! macro does not allows to set the same macro parameter multiple times with different configuration conditional checks, but the next approach can be used instead:

#![allow(unused)]
fn main() {
#[cfg(feature = "ssr")]
let param = "ssr-lang";
#[cfg(feature = "hydrate")]
let param = "hydrate-lang";
#[cfg(debug_assertions)]
let param = "debug-lang";

leptos_fluent! {{
    // ...
    #[cfg(any(feature = "ssr", feature = "hydrate", debug_assertions))]
    url_param: param,
    #[cfg(debug_assertions)]
    initial_language_from_url_param: true,
}}
}