feat(server): display custom list metadata (e.g. nutrition) on recipe pages

docs/server.md

@@ -50,3 +50,51 @@ cook server --host
 - The web interface supports recipe browsing, scaling, search, and shopping list management
 - The UI language is negotiated per request from the browser's `Accept-Language` header — each visitor sees the interface in their own language (supported: `en-US`, `de-DE`, `nl-NL`, `fr-FR`, `es-ES`, `eu-ES`, `sv-SE`). For static sites, see the `--lang` flag of [`cook build web`](build.md#localization).
 - Mobile-friendly responsive layout
+
+## Custom Metadata Families (e.g. Nutrition)
+
+Beyond the [standard Cooklang metadata keys](https://cooklang.org/docs/spec/#canonical-metadata) (`servings`, `time`, `course`, `author`, ...), any YAML frontmatter key whose value is a **list** or a **mapping** is shown on the recipe page as its own line below the tags, grouped by key — one line per family. This works for any such key, not just `nutrition` — e.g. `allergens:` below renders as its own "Allergens" line automatically, with no code changes required.
+
+```yaml
+---
+tags:
+  - vegan
+  - gluten-free
+nutrition:
+  kcal: 258
+  proteins: 4.2
+  lipids: 4.8
+  sugars: 39.4
+  fibers: 5.3
+file:
+  created-by: Yannick
+  created-at: 2026-08-20
+  modified-by: Yannick
+  modified-at: 2026-08-24
+allergens:
+  - gluten
+  - tree nuts
+---
+```
+
+### Two forms
+
+- **Mapping** (recommended, shown above): `field: value`. A bare number gets its unit inferred from the field name for `nutrition` (`kcal` → `kcal`, everything else → `g`); `field: "45.3%g"` also works if you want to spell out a different unit.
+- **List** (legacy, still supported): `- "258%kcal"`. The `%` is replaced with a space when displayed (`258 kcal`); entries without a `%` are shown as-is. Because list entries are free text, they aren't translated — write them in whichever language you want displayed.
+
+### Hiding a family or a single entry
+
+Prefix a key with `.` to hide it from the recipe page: `.internal-notes:` hides the whole family, and `.lipids:` (inside `nutrition:`) hides just that one entry while the rest of the family still shows. `tags` is never treated as a custom family — it keeps its own dedicated row above, and can't be hidden this way.
+
+### Specific renderers: `nutrition` and `file`/`meta`
+
+Two families get dedicated icons and (for `nutrition`) localized labels, matched on their fields:
+
+- **`nutrition`**: `kcal`/`cal`/`energy` (flame), `proteins` (meat), `lipids`/`fat` (droplet), `saturated-fat` (filled droplet), `carbohydrates`/`carbs` (bread), `sugars` (candy), `fibers`/`fibre` (wheat), `salt`/`sodium` (salt shaker). The nutrient name (everything but `kcal`, which needs none) is translated into the viewer's UI language — see [Localization](build.md#localization) for the supported locales.
+- **`file`** (or `meta`, both work): `created-by`/`created-at`/`modified-by`/`modified-at` — person, calendar, pencil, and history icons respectively, with a translated `"Label: value"` line (e.g. `"Modified at: 2026-08-24"`, `"Modifié le : 2026-08-24"` in French, with the French space before `:`).
+
+Every other family (like `allergens` above) falls back to a generic rendering: list entries as-authored, mapping entries as `"field: value"`, no icon. Adding a third specific renderer means adding a case in `src/web/family_renderers/mod.rs`'s `renderer_for` plus a small renderer file next to `nutrition.rs`/`file.rs` — there's no filename-based auto-discovery (Rust has no runtime filesystem scanning for this), so that match statement is always the definitive list of which families get special treatment.
+
+### Recipe list page
+
+Only the calorie entry from `nutrition` (`kcal`) is shown, as a compact badge next to the tags — the other custom families are only shown on the recipe detail page, to keep list cards compact.

locales/de-DE/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Gesamtzeit
 meta-servings = Portionen
 meta-difficulty = Schwierigkeit
 meta-description = Beschreibung
+meta-created-by = Erstellt von
+meta-created-at = Erstellt am
+meta-modified-by = Geändert von
+meta-modified-at = Geändert am
+
+# Nutrition (benutzerdefinierte `nutrition:`-Metadaten)
+nutrition-per-serving = pro Portion
+nutrition-proteins = Eiweiß
+nutrition-lipids = Fett
+nutrition-saturated-fat = gesättigte Fettsäuren
+nutrition-carbohydrates = Kohlenhydrate
+nutrition-sugars = Zucker
+nutrition-fibers = Ballaststoffe
+nutrition-salt = Salz
 
 # Recipe Types
 recipe-type-menu = Menü

locales/en-US/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Total Time
 meta-servings = Servings
 meta-difficulty = Difficulty
 meta-description = Description
+meta-created-by = Created by
+meta-created-at = Created at
+meta-modified-by = Modified by
+meta-modified-at = Modified at
+
+# Nutrition (custom `nutrition:` metadata)
+nutrition-per-serving = per serving
+nutrition-proteins = proteins
+nutrition-lipids = fat
+nutrition-saturated-fat = saturated fat
+nutrition-carbohydrates = carbohydrates
+nutrition-sugars = sugars
+nutrition-fibers = fiber
+nutrition-salt = salt
 
 # Recipe Types
 recipe-type-menu = Menu

locales/es-ES/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Tiempo Total
 meta-servings = Porciones
 meta-difficulty = Dificultad
 meta-description = Descripción
+meta-created-by = Creado por
+meta-created-at = Creado el
+meta-modified-by = Modificado por
+meta-modified-at = Modificado el
+
+# Nutrición (metadatos personalizados `nutrition:`)
+nutrition-per-serving = por porción
+nutrition-proteins = proteínas
+nutrition-lipids = grasas
+nutrition-saturated-fat = grasas saturadas
+nutrition-carbohydrates = hidratos de carbono
+nutrition-sugars = azúcares
+nutrition-fibers = fibra
+nutrition-salt = sal
 
 # Recipe Types
 recipe-type-menu = Menú

locales/eu-ES/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Denbora guztira
 meta-servings = Anoak
 meta-difficulty = Zailtasuna
 meta-description = Deskribapena
+meta-created-by = Sortzailea
+meta-created-at = Sortze data
+meta-modified-by = Aldatzailea
+meta-modified-at = Aldatze data
+
+# Nutrizioa (`nutrition:` metadatu pertsonalizatuak)
+nutrition-per-serving = anoko
+nutrition-proteins = proteinak
+nutrition-lipids = gantzak
+nutrition-saturated-fat = gantz aseak
+nutrition-carbohydrates = karbohidratoak
+nutrition-sugars = azukreak
+nutrition-fibers = zuntza
+nutrition-salt = gatza
 
 # Recipe Types
 recipe-type-menu = Menua

locales/fr-FR/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Temps Total
 meta-servings = Portions
 meta-difficulty = Difficulté
 meta-description = Description
+meta-created-by = Créé par
+meta-created-at = Créé le
+meta-modified-by = Modifié par
+meta-modified-at = Modifié le
+
+# Nutrition (métadonnées personnalisées `nutrition:`)
+nutrition-per-serving = par portion
+nutrition-proteins = protéines
+nutrition-lipids = lipides
+nutrition-saturated-fat = graisses saturées
+nutrition-carbohydrates = glucides
+nutrition-sugars = sucres
+nutrition-fibers = fibres
+nutrition-salt = sel
 
 # Recipe Types
 recipe-type-menu = Menu

locales/nl-NL/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Totale tijd
 meta-servings = Porties
 meta-difficulty = Moeilijkheidsgraad
 meta-description = Beschrijving
+meta-created-by = Aangemaakt door
+meta-created-at = Aangemaakt op
+meta-modified-by = Gewijzigd door
+meta-modified-at = Gewijzigd op
+
+# Nutrition (aangepaste `nutrition:`-metadata)
+nutrition-per-serving = per portie
+nutrition-proteins = eiwitten
+nutrition-lipids = vetten
+nutrition-saturated-fat = verzadigd vet
+nutrition-carbohydrates = koolhydraten
+nutrition-sugars = suikers
+nutrition-fibers = vezels
+nutrition-salt = zout
 
 # Recipe Types
 recipe-type-menu = Menu

locales/sv-SE/recipes.ftl

@@ -36,6 +36,20 @@ meta-total-time = Total tid
 meta-servings = Portioner
 meta-difficulty = Svårighet
 meta-description = Beskrivning
+meta-created-by = Skapad av
+meta-created-at = Skapad
+meta-modified-by = Ändrad av
+meta-modified-at = Ändrad
+
+# Nutrition (anpassad `nutrition:`-metadata)
+nutrition-per-serving = per portion
+nutrition-proteins = protein
+nutrition-lipids = fett
+nutrition-saturated-fat = mättat fett
+nutrition-carbohydrates = kolhydrater
+nutrition-sugars = socker
+nutrition-fibers = fibrer
+nutrition-salt = salt
 
 # Recipe Types
 recipe-type-menu = Meny

src/web/builders.rs

@@ -68,7 +68,7 @@ pub fn build_recipes_template(input: RecipesBuildInput<'_>) -> Result<RecipesTem
         };
 
         // Extract tags, image, is_menu, and file timestamps if this is a recipe
-        let (tags, image_path, is_menu, modified_at, created_at) =
+        let (tags, nutrition_kcal, image_path, is_menu, modified_at, created_at) =
             if let Some(ref recipe) = child.recipe {
                 let img_path = recipe.title_image().clone().and_then(|img| {
                     if img.starts_with("http://") || img.starts_with("https://") {
@@ -108,13 +108,14 @@ pub fn build_recipes_template(input: RecipesBuildInput<'_>) -> Result<RecipesTem
 
                 (
                     recipe.tags(),
+                    crate::web::family_renderers::extract_nutrition_kcal(recipe.metadata()),
                     img_path,
                     recipe.is_menu(),
                     modified_at,
                     created_at,
                 )
             } else {
-                (Vec::new(), None, false, None, None)
+                (Vec::new(), None, None, false, None, None)
             };
 
         items.push(RecipeItem {
@@ -128,6 +129,7 @@ pub fn build_recipes_template(input: RecipesBuildInput<'_>) -> Result<RecipesTem
             },
             description: None,
             tags,
+            nutrition_kcal,
             image_path,
             is_menu,
             modified_at,
@@ -715,11 +717,20 @@ pub fn build_recipe_template(input: RecipeBuildInput<'_>) -> Result<RecipeBuildO
                 if key_str.starts_with("source.") || key_str.starts_with("time.") {
                     continue;
                 }
+                // A key prefixed with "." is hidden from the recipe page.
+                if key_str.starts_with('.') {
+                    continue;
+                }
 
                 custom_metadata.push((key_str.to_string(), val_str.to_string()));
             }
         }
 
+        let custom_lists = crate::web::family_renderers::build_custom_list_families(
+            recipe.metadata.map_filtered(),
+            &lang,
+        );
+
         Some(RecipeMetadata {
             servings: get_field("servings"),
             time: get_field("time"),
@@ -740,6 +751,7 @@ pub fn build_recipe_template(input: RecipeBuildInput<'_>) -> Result<RecipeBuildO
             source: get_field("source").or_else(|| get_field("source.name")),
             source_url: get_field("source.url"),
             custom: custom_metadata,
+            custom_lists,
         })
     };
 
@@ -1007,10 +1019,19 @@ fn build_menu_template_inner(
         let mut custom_metadata = Vec::new();
         for (key, value) in recipe.metadata.map_filtered() {
             if let (Some(key_str), Some(val_str)) = (key.as_str(), value.as_str()) {
+                // A key prefixed with "." is hidden from the recipe page.
+                if key_str.starts_with('.') {
+                    continue;
+                }
                 custom_metadata.push((key_str.to_string(), val_str.to_string()));
             }
         }
 
+        let custom_lists = crate::web::family_renderers::build_custom_list_families(
+            recipe.metadata.map_filtered(),
+            &lang,
+        );
+
         Some(RecipeMetadata {
             servings: get_field("servings"),
             time: get_field("time"),
@@ -1029,6 +1050,7 @@ fn build_menu_template_inner(
             source: get_field("source").or_else(|| get_field("source.name")),
             source_url: get_field("source.url"),
             custom: custom_metadata,
+            custom_lists,
         })
     };
 

src/web/family_renderers/file.rs

@@ -0,0 +1,75 @@
+// MIT License
+//
+// Copyright (c) 2024 cooklang
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+//! Specific renderer for the `file:`/`meta:` family (`created-by`,
+//! `created-at`, `modified-by`, `modified-at`).
+
+use super::{format_mapping_entry_default, FamilyRenderer};
+use fluent_templates::Loader;
+use unic_langid::LanguageIdentifier;
+
+/// Tabler Icons (MIT license, https://tabler.io/icons).
+const ICON_USER: &str = r##"<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="8" r="3.5"/><path d="M5 20c0-3.5 3-6 7-6s7 2.5 7 6"/></svg>"##;
+const ICON_CALENDAR: &str = r##"<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="4" y="5" width="16" height="15" rx="2"/><path d="M4 10h16M8 3v4M16 3v4"/></svg>"##;
+const ICON_PENCIL: &str = r##"<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M15.5 4.5 19 8l-10 10H5v-4Z"/></svg>"##;
+const ICON_HISTORY: &str = r##"<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M4 9a8 8 0 1 1 1.5 6.5"/><path d="M4 4v5h5"/><path d="M12 8v4l3 2"/></svg>"##;
+
+/// Specific renderer for the `file`/`meta` family.
+pub(super) struct FileRender;
+
+impl FamilyRenderer for FileRender {
+    fn mapping_icon(&self, field: &str) -> Option<&'static str> {
+        match field.to_lowercase().replace('_', "-").as_str() {
+            "created-by" => Some(ICON_USER),
+            "created-at" => Some(ICON_CALENDAR),
+            "modified-by" => Some(ICON_PENCIL),
+            "modified-at" => Some(ICON_HISTORY),
+            _ => None,
+        }
+    }
+
+    /// `("created-by", "Yannick")` -> `"Created by: Yannick"` (en) /
+    /// `"Créé par : Yannick"` (fr, with the French space before `:`) /
+    /// `"Created by: Yannick"` (en), via Fluent. Any other field falls back
+    /// to the raw field name, same as [`super::generic::GenericRenderer`].
+    fn format_mapping_entry(&self, field: &str, raw: &str, lang: &LanguageIdentifier) -> String {
+        let key = match field.to_lowercase().replace('_', "-").as_str() {
+            "created-by" => "meta-created-by",
+            "created-at" => "meta-created-at",
+            "modified-by" => "meta-modified-by",
+            "modified-at" => "meta-modified-at",
+            _ => return format_mapping_entry_default(field, raw),
+        };
+        let label = crate::web::i18n::LOCALES.lookup(lang, key);
+        format!("{label}{}{}", colon_separator(lang), raw.trim())
+    }
+}
+
+/// French typography puts a (narrow no-break) space before `:`; other
+/// supported locales just follow it with a space.
+fn colon_separator(lang: &LanguageIdentifier) -> &'static str {
+    if lang.language == "fr" {
+        "\u{202f}: "
+    } else {
+        ": "
+    }
+}

src/web/family_renderers/generic.rs

@@ -0,0 +1,31 @@
+// MIT License
+//
+// Copyright (c) 2024 cooklang
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+use super::FamilyRenderer;
+
+/// Fallback renderer for any family without a specific one: list entries are
+/// shown as-authored (`"value%unit"` -> `"value unit"`), mapping entries as
+/// `"field: value"`. No icons. Used by [`super::renderer_for`] whenever a
+/// family key doesn't match a specific renderer.
+pub(super) struct GenericRenderer;
+
+impl FamilyRenderer for GenericRenderer {}