Add support for localized validation errors and hints. Add an example…

… for testing localized validation support.

examples/assets/localizations/en-US/validation-localized.ftl

@@ -0,0 +1,27 @@
+window-title = Localized validation example
+
+language-en-us = English (United States)
+language-es-es = Spanish (Spain)
+
+#
+# Translations specific to the example form
+#
+form-example-hinted-label = Hinted
+form-example-not-hinted-label = Not hinted
+
+# Specific validation reason
+form-input-invalid-non-whitespace-required = This field must have at least one non-whitespace character
+
+#
+# Translations applicable to all forms
+#
+
+# Hints
+form-hint-field-required = * Required
+
+# Generic buttons
+form-generic-submit-button = Submit
+form-generic-reset-button = Reset
+
+# Generic validation reasons
+form-generic-invalid-empty = This field cannot be empty.

examples/assets/localizations/es-ES/validation-localized.ftl

@@ -0,0 +1,27 @@
+window-title = Ejemplo de validación localizada
+
+language-en-us = Inglés (Estados Unidos)
+language-es-es = Español (España)
+
+#
+# Traducciones específicas del formulario de ejemplo
+#
+form-example-hinted-label = Insinuado
+form-example-not-hinted-label = No insinuado
+
+# Razón de validación específica
+form-input-invalid-non-whitespace-required = Este campo debe tener al menos un carácter que no sea un espacio en blanco
+
+#
+# Traducciones aplicables a todos los formularios
+#
+
+# Sugerencias
+form-hint-field-required = * Requerido
+
+# Botones genéricos
+form-generic-submit-button = Enviar
+form-generic-reset-button = Restablecer
+
+# Razones genéricas de validación
+form-generic-invalid-empty = Este campo no puede estar vacío.

examples/validation-localized.rs

@@ -0,0 +1,131 @@
+//! An example that demonstrates localized validation messages and errors.
+//!
+//! Note how all the form elements, hints and validation error messages use `localize!`
+//!
+//! Refer to the `localization.rs` example for more details on how localization works in general.
+
+use unic_langid::LanguageIdentifier;
+use cushy::figures::units::Lp;
+use cushy::value::{Destination, Dynamic, IntoValue, Source, Validations, Value};
+use cushy::widget::MakeWidget;
+use cushy::widgets::input::InputValue;
+use cushy::{localize, MaybeLocalized, Open, PendingApp};
+use cushy::localization::Localization;
+
+// This example is based on the `validation.rs` example and should be kept in sync with it.
+
+fn form() -> impl MakeWidget {
+    let text = Dynamic::default();
+    let validations = Validations::default();
+
+    localize!("form-example-hinted-label")
+        .and(
+            text.to_input()
+                .validation(validations.validate(&text, validate_input))
+                .hint(localize!("form-hint-field-required")),
+        )
+        .and(localize!("form-example-not-hinted-label"))
+        .and(
+            text.to_input()
+                .validation(validations.validate(&text, validate_input)),
+        )
+        .and(
+            localize!("form-generic-submit-button")
+                .into_button()
+                .on_click(validations.clone().when_valid(move |_| {
+
+                    // Note: This is non-localized string is for developers, not users of the UI.
+                    println!(
+                        "Success! This callback only happens when all associated validations are valid"
+                    );
+                })),
+        )
+        .and(localize!("form-generic-reset-button").into_button().on_click(move |_| {
+            let _value = text.take();
+            validations.reset();
+        }))
+        .into_rows()
+        .pad()
+        .width(Lp::inches(6))
+        .centered()
+        .make_widget()
+}
+
+#[allow(clippy::ptr_arg)] // Changing &String to &str breaks type inference
+fn validate_input(input: &String) -> Result<(), Value<MaybeLocalized>> {
+    if input.is_empty() {
+        Err(localize!("form-generic-invalid-empty").into_value())
+    } else if input.trim().is_empty() {
+        Err(localize!("form-input-invalid-non-whitespace-required").into_value())
+    } else {
+        Ok(())
+    }
+}
+
+#[derive(Default, Eq, PartialEq, Debug, Clone, Copy)]
+pub enum LanguageChoices {
+    #[default]
+    EnUs,
+    EsEs,
+}
+
+impl LanguageChoices {
+    pub fn to_locale(&self) -> LanguageIdentifier {
+        match self {
+            LanguageChoices::EnUs => "en-US".parse().unwrap(),
+            LanguageChoices::EsEs => "es-ES".parse().unwrap(),
+        }
+    }
+}
+
+#[cushy::main]
+fn main(app: &mut PendingApp) -> cushy::Result {
+    app.cushy().localizations().add_default(
+        Localization::for_language(
+            "en-US",
+            include_str!("assets/localizations/en-US/validation-localized.ftl"),
+        )
+            .expect("valid language id"),
+    );
+    app.cushy().localizations().add(
+        Localization::for_language(
+            "es-ES",
+            include_str!("assets/localizations/es-ES/validation-localized.ftl"),
+        )
+            .expect("valid language id"),
+    );
+
+    let dynamic_locale: Dynamic<LanguageChoices> = Dynamic::default();
+
+    ui(&dynamic_locale)
+        .localized_in(dynamic_locale.map_each(LanguageChoices::to_locale))
+        .into_window()
+        .titled(localize!("window-title"))
+        .open(app)?;
+
+    Ok(())
+}
+
+fn language_selector(dynamic_locale: &Dynamic<LanguageChoices>) -> impl MakeWidget {
+    let dynamic_language_selector = dynamic_locale
+        .new_radio(LanguageChoices::EnUs)
+        .labelled_by(localize!("language-en-us"))
+        .and(
+            dynamic_locale
+                .new_radio(LanguageChoices::EsEs)
+                .labelled_by(localize!("language-es-es")),
+        )
+        .into_rows()
+        .contain();
+
+    dynamic_language_selector
+        .make_widget()
+}
+
+fn ui(dynamic_locale: &Dynamic<LanguageChoices>) -> impl MakeWidget {
+    language_selector(dynamic_locale)
+        .and(form())
+        .into_rows()
+        .centered()
+        .make_widget()
+}

examples/validation.rs

@@ -2,7 +2,10 @@ use cushy::figures::units::Lp;
 use cushy::value::{Destination, Dynamic, Validations};
 use cushy::widget::MakeWidget;
 use cushy::widgets::input::InputValue;
-use cushy::Run;
+use cushy::{localize, Run};
+
+// For an example of localized validation, see the `validation-localized.rs` example which should
+// be kept in sync with this example.
 
 fn main() -> cushy::Result {
     let text = Dynamic::default();

src/lib.rs

@@ -39,7 +39,7 @@ pub mod localization;
 use std::ops::{Add, AddAssign, Sub, SubAssign};
 
 /// A string that may be a localized message.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum MaybeLocalized {
     /// A non-localized message.
     Text(String),

src/localization.rs

@@ -234,7 +234,7 @@ impl DynamicDisplay for MaybeLocalized {
 }
 
 /// The primary of defining localized message
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Localize {
     key: Cow<'static, str>,
     args: Vec<(String, Value<FluentValue<'static>>)>,