🥅 Add safe results handling

pagetop/src/lib.rs

@@ -129,6 +129,9 @@ static_locales!(LOCALES_PAGETOP);
 // PUBLIC API.
 // *************************************************************************************************
 
+// Handling safe results.
+pub mod result;
+
 // Functions and macro helpers.
 pub mod util;
 

pagetop/src/locale.rs

@@ -88,16 +88,21 @@
 //! ```
 
 use crate::html::{Markup, PreEscaped};
-use crate::{config, kv, trace, LazyStatic, LOCALES_PAGETOP};
+use crate::result::{SafeResult, TraceErr};
+use crate::{config, kv, LazyStatic, LOCALES_PAGETOP};
 
 pub use fluent_templates;
+pub use unic_langid::LanguageIdentifier;
 
 pub(crate) use fluent_templates::Loader;
 pub(crate) use fluent_templates::StaticLoader as Locales;
-pub(crate) use unic_langid::{langid, LanguageIdentifier};
+
+use unic_langid::langid;
 
 use std::collections::HashMap;
 
+const LANGUAGE_SET_FAILURE: &str = "language_set_failure";
+
 static LANGUAGES: LazyStatic<HashMap<String, (LanguageIdentifier, &str)>> = LazyStatic::new(|| {
     kv![
         "en"    => (langid!("en-US"), "English"),
@@ -114,19 +119,22 @@ static FALLBACK_LANGID: LazyStatic<LanguageIdentifier> = LazyStatic::new(|| lang
 /// ([Unicode Language Identifier](https://unicode.org/reports/tr35/tr35.html#Unicode_language_identifier))
 /// global para la aplicación a partir de `SETTINGS.app.language`.
 pub(crate) static LANGID: LazyStatic<&LanguageIdentifier> =
-    LazyStatic::new(|| langid_for(config::SETTINGS.app.language.as_str()));
+    LazyStatic::new(|| langid_for(config::SETTINGS.app.language.as_str()).unwrap_or_fallback());
 
-pub fn langid_for(language: &str) -> &LanguageIdentifier {
-    match LANGUAGES.get(language) {
-        Some((langid, _)) => langid,
-        _ => {
-            trace::warn!(
-                "{} \"{}\"! {}",
-                "Failed to set language. Unicode Language Identifier",
-                config::SETTINGS.app.language,
-                "is not accepted. Using \"en-US\", check the settings file",
-            );
-            &FALLBACK_LANGID
+pub fn langid_for(language: impl Into<String>) -> SafeResult<&'static LanguageIdentifier> {
+    let language = language.into();
+    match LANGUAGES.get(language.as_str()) {
+        Some((langid, _)) => SafeResult::Ok(langid),
+        None => {
+            if language.is_empty() {
+                SafeResult::Ok(&FALLBACK_LANGID)
+            } else {
+                SafeResult::Err(TraceErr::warn(
+                    L10n::l(LANGUAGE_SET_FAILURE)
+                        .with_arg("language", config::SETTINGS.app.language.as_str()),
+                    &FALLBACK_LANGID,
+                ))
+            }
         }
     }
 }
@@ -230,6 +238,32 @@ impl L10n {
         }
     }
 
+    pub(crate) fn message(&self) -> String {
+        match &self.op {
+            L10nOp::None => "".to_owned(),
+            L10nOp::Text(text) => text.to_owned(),
+            L10nOp::Translate(key) => match self.locales {
+                Some(locales) => locales
+                    .lookup_with_args(
+                        match key.as_str() {
+                            LANGUAGE_SET_FAILURE => &FALLBACK_LANGID,
+                            _ => &LANGID,
+                        },
+                        key,
+                        &self
+                            .args
+                            .iter()
+                            .fold(HashMap::new(), |mut args, (key, value)| {
+                                args.insert(key.to_string(), value.to_owned().into());
+                                args
+                            }),
+                    )
+                    .unwrap_or(key.to_owned()),
+                None => key.to_owned(),
+            },
+        }
+    }
+
     pub fn escaped(&self, langid: &LanguageIdentifier) -> Markup {
         PreEscaped(self.using(langid).unwrap_or_default())
     }

pagetop/src/locale/en-US/trace.ftl

@@ -0,0 +1,4 @@
+# DEBUG.
+
+# ERRORS.
+language_set_failure = Failed to set language. Unicode Language Identifier "{$language}" is not accepted. Using "en-US", check the settings file

pagetop/src/locale/es-ES/trace.ftl

@@ -0,0 +1,4 @@
+# DEBUG.
+
+# ERRORS.
+language_set_failure = Error al establecer idioma. El Identificador de Lenguaje Unicode "{$language}" no es válido. Se usará "en-US". Comprobar archivo de configuración

pagetop/src/prelude.rs

@@ -6,6 +6,9 @@ pub use crate::{concat_string, fn_builder, main, paste, test};
 // Global.
 pub use crate::{Handle, HashMapResources, LazyStatic, ResultExt, Weight};
 
+// Handling safe results.
+pub use crate::result::{SafeResult, TraceErr};
+
 // Functions and macro helpers.
 pub use crate::util;
 pub use crate::{kv, new_handle};

pagetop/src/result.rs

@@ -0,0 +1,45 @@
+//! Handling safe results.
+
+use crate::locale::L10n;
+use crate::trace;
+
+pub struct TraceErr<T> {
+    message: String,
+    fallback: T,
+}
+
+impl<T> TraceErr<T> {
+    pub fn warn(trace: L10n, fallback: T) -> Self {
+        let message = trace.message();
+        trace::warn!(message);
+        TraceErr { message, fallback }
+    }
+
+    pub fn error(trace: L10n, fallback: T) -> Self {
+        let message = trace.message();
+        trace::error!(message);
+        TraceErr { message, fallback }
+    }
+
+    pub fn message(self) -> String {
+        self.message
+    }
+
+    pub fn fallback(self) -> T {
+        self.fallback
+    }
+}
+
+pub enum SafeResult<T> {
+    Ok(T),
+    Err(TraceErr<T>),
+}
+
+impl<T> SafeResult<T> {
+    pub fn unwrap_or_fallback(self) -> T {
+        match self {
+            SafeResult::Ok(result) => result,
+            SafeResult::Err(trace) => trace.fallback(),
+        }
+    }
+}