From a4c7d610a3f93bfc7ac0cb3cc9c2d070f1dd1663 Mon Sep 17 00:00:00 2001
From: Alex Kotov <kotovalexarian@gmail.com>
Date: Sat, 24 Oct 2020 19:53:53 +0500
Subject: [PATCH] Add helper "translate"

---
 Cargo.lock                     |  1 +
 Cargo.toml                     |  1 +
 src/i18n.rs                    |  2 ++
 src/i18n/handlebars_helpers.rs | 44 ++++++++++++++++++++++++++++++++++
 src/web.rs                     | 16 +++++++++++--
 templates/home/index.html.hbs  |  6 +++--
 6 files changed, 66 insertions(+), 4 deletions(-)
 create mode 100644 src/i18n/handlebars_helpers.rs

diff --git a/Cargo.lock b/Cargo.lock
index a98bce2..65bc4a9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -309,6 +309,7 @@ dependencies = [
  "diesel",
  "dotenv",
  "fluent-bundle",
+ "handlebars",
  "r2d2",
  "regex",
  "rocket",
diff --git a/Cargo.toml b/Cargo.toml
index 9ada3dc..3267a18 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,6 +16,7 @@ publish = true
 bcrypt = "0.8.2"
 dotenv = "0.15.0"
 fluent-bundle = "0.13.1"
+handlebars = "1.1.0"
 r2d2 = "0.8.9"
 regex = "1.4.1"
 rocket_csrf = "0.2.0"
diff --git a/src/i18n.rs b/src/i18n.rs
index 2eb479f..58ddd60 100644
--- a/src/i18n.rs
+++ b/src/i18n.rs
@@ -1,3 +1,5 @@
+pub mod handlebars_helpers;
+
 use std::collections::HashMap;
 
 use fluent_bundle::{FluentError, FluentResource};
diff --git a/src/i18n/handlebars_helpers.rs b/src/i18n/handlebars_helpers.rs
new file mode 100644
index 0000000..606c767
--- /dev/null
+++ b/src/i18n/handlebars_helpers.rs
@@ -0,0 +1,44 @@
+use super::I18n;
+
+use handlebars::{
+    Context,
+    Handlebars,
+    Helper,
+    HelperDef,
+    HelperResult,
+    Output,
+    RenderContext,
+    RenderError,
+};
+
+pub fn translate(i18n: std::sync::Arc<I18n>) -> Box<dyn HelperDef> {
+    Box::new(move |
+        helper: &Helper,
+        _: &Handlebars,
+        _: &Context,
+        _: &mut RenderContext,
+        output: &mut dyn Output,
+    | -> HelperResult {
+        let locale = helper.param(0)
+            .ok_or(RenderError::new("expected locale param"))?
+            .value().as_str()
+            .ok_or(RenderError::new("expected locale param"))?;
+
+        let key = helper.param(1)
+            .ok_or(RenderError::new("expected key param"))?
+            .value().as_str()
+            .ok_or(RenderError::new("expected key param"))?;
+
+        let i18n = i18n.clone();
+
+        let l10n = i18n.l10n(locale).ok()
+            .ok_or(RenderError::new("unknown locale"))?;
+
+        let translated = l10n.translate(key).ok()
+            .ok_or(RenderError::new("translation error"))?;
+
+        output.write(&translated)?;
+
+        Ok(())
+    })
+}
diff --git a/src/web.rs b/src/web.rs
index fefa328..7b0cb24 100644
--- a/src/web.rs
+++ b/src/web.rs
@@ -1,6 +1,6 @@
 use crate::config;
 use crate::database;
-use crate::i18n::I18n;
+use crate::i18n::{self, I18n};
 use crate::routes;
 
 use rocket_contrib::serve::{Options as ServeOptions, StaticFiles};
@@ -17,12 +17,24 @@ pub fn rocket(config: &config::Config) -> Result<rocket::Rocket, ()> {
         Ok(i18n) => i18n,
     };
 
+    let i18n_arc = match I18n::new(&locales_path, &["en", "ru"]) {
+        Err(_) => return Err(()),
+        Ok(i18n) => std::sync::Arc::new(i18n),
+    };
+
     let result = rocket::custom(rocket_config)
         .manage(i18n)
         .manage(database::create_db_pool(config))
         .attach(rocket_csrf::Fairing::new())
-        .attach(Template::custom(|engines| {
+        .attach(Template::custom(move |engines| {
             engines.handlebars.set_strict_mode(true);
+
+            let i18n_arc = i18n_arc.clone();
+
+            engines.handlebars.register_helper(
+                "translate",
+                i18n::handlebars_helpers::translate(i18n_arc),
+            );
         }))
         .mount("/", routes::routes())
         .mount("/", StaticFiles::new(public_path, ServeOptions::None));
diff --git a/templates/home/index.html.hbs b/templates/home/index.html.hbs
index 7c62257..1aa95fd 100644
--- a/templates/home/index.html.hbs
+++ b/templates/home/index.html.hbs
@@ -1,6 +1,8 @@
 <div class="jumbotron jumbotron-fluid text-center">
   <div class="container">
-    <h1>{{ i18n_fedihub }}</h1>
-    <p class="lead">{{ i18n_federated_services_without_censorship }}</p>
+    <h1>{{ translate "en" "fedihub" }}</h1>
+    <p class="lead">
+      {{ translate "en" "federated-services-without-censorship" }}
+    </p>
   </div>
 </div>