From 4d17f383ae7eb44f5a8d2610b262eda79ee3e040 Mon Sep 17 00:00:00 2001
From: Bartosz Prusinowski <bartosz@interactivethings.com>
Date: Fri, 1 Dec 2023 11:53:05 +0100
Subject: [PATCH 1/2] feat: Landing page can be localized

---
 CHANGELOG.md                   |  3 ++-
 app/rdf/query-cube-metadata.ts |  5 ++++-
 app/rdf/query-utils.ts         | 15 +++++++++++----
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 29140544b..866705648 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,8 @@ You can also check the [release page](https://github.com/visualize-admin/visuali
 
 ## Unreleased
 
-Nothing yet.
+- Features
+  - Localized cube landing pages are now supported (dcat:landingPage) 🌎
 
 # [3.24.2] - 2023-11-28
 
diff --git a/app/rdf/query-cube-metadata.ts b/app/rdf/query-cube-metadata.ts
index e275cabdc..6be465414 100644
--- a/app/rdf/query-cube-metadata.ts
+++ b/app/rdf/query-cube-metadata.ts
@@ -140,7 +140,10 @@ export const getCubeMetadata = async (
       ?contactPoint ${ns.vcard.hasEmail} ?contactPointEmail .
     }
     OPTIONAL { ?iri ${ns.dcterms.publisher} ?publisher . }
-    OPTIONAL { ?iri ${ns.dcat.landingPage} ?landingPage . }
+    ${buildLocalizedSubQuery("iri", "dcat:landingPage", "landingPage", {
+      locale,
+      fallbackToNonLocalized: true,
+    })}
     OPTIONAL { ?iri ${ns.schema.expires} ?expires . }
     OPTIONAL { ?iri ${ns.schema.workExample} ?workExample . }
   `.GROUP().BY`?iri`.THEN.BY`?identifier`.THEN.BY`?title`.THEN.BY`?description`
diff --git a/app/rdf/query-utils.ts b/app/rdf/query-utils.ts
index aa44a610e..635f06b12 100644
--- a/app/rdf/query-utils.ts
+++ b/app/rdf/query-utils.ts
@@ -10,7 +10,13 @@ export const buildLocalizedSubQuery = (
   s: string,
   p: string,
   o: string,
-  { locale }: { locale: string }
+  {
+    locale,
+    fallbackToNonLocalized,
+  }: {
+    locale: string;
+    fallbackToNonLocalized?: boolean;
+  }
 ) => {
   // Include the empty locale as well.
   const locales = getOrderedLocales(locale).concat("");
@@ -23,9 +29,10 @@ export const buildLocalizedSubQuery = (
         }`
     )
     .join("\n")}
-      BIND(COALESCE(${locales
-        .map((locale) => `?${o}_${locale}`)
-        .join(", ")}) AS ?${o})
+    ${fallbackToNonLocalized ? `OPTIONAL { ?${s} ${p} ?${o}_raw }` : ""}
+      BIND(COALESCE(${locales.map((locale) => `?${o}_${locale}`).join(", ")} ${
+    fallbackToNonLocalized ? `, ?${o}_raw` : ``
+  }) AS ?${o})
   `;
 };
 

From 35912ddbecfa4b537cfb0d83e24e5645c59301f2 Mon Sep 17 00:00:00 2001
From: Bartosz Prusinowski <bartosz@interactivethings.com>
Date: Fri, 1 Dec 2023 12:41:09 +0100
Subject: [PATCH 2/2] chore: Add query-utils unit tests

---
 app/rdf/query-utils.spec.ts | 67 +++++++++++++++++++++++++++++++++++++
 app/rdf/query-utils.ts      | 20 ++++++-----
 2 files changed, 79 insertions(+), 8 deletions(-)
 create mode 100644 app/rdf/query-utils.spec.ts

diff --git a/app/rdf/query-utils.spec.ts b/app/rdf/query-utils.spec.ts
new file mode 100644
index 000000000..34ad182b1
--- /dev/null
+++ b/app/rdf/query-utils.spec.ts
@@ -0,0 +1,67 @@
+import { buildLocalizedSubQuery } from "./query-utils";
+
+describe("buildLocalizedSubQuery", () => {
+  it("should build a subquery with the given locale", () => {
+    const subQuery = buildLocalizedSubQuery("s", "p", "o", {
+      locale: "it",
+    });
+    expect(subQuery).toEqual(
+      // it locale must be first!
+      `OPTIONAL {
+  ?s p ?o_it .
+  FILTER(LANG(?o_it) = "it")
+}
+OPTIONAL {
+  ?s p ?o_de .
+  FILTER(LANG(?o_de) = "de")
+}
+OPTIONAL {
+  ?s p ?o_fr .
+  FILTER(LANG(?o_fr) = "fr")
+}
+OPTIONAL {
+  ?s p ?o_en .
+  FILTER(LANG(?o_en) = "en")
+}
+OPTIONAL {
+  ?s p ?o_ .
+  FILTER(LANG(?o_) = "")
+}
+BIND(COALESCE(?o_it, ?o_de, ?o_fr, ?o_en, ?o_) AS ?o)`
+    );
+  });
+
+  it("should build a subquery with the given locale, falling back to non-localized property", () => {
+    const subQuery = buildLocalizedSubQuery("s", "p", "o", {
+      locale: "en",
+      fallbackToNonLocalized: true,
+    });
+    expect(subQuery).toEqual(
+      // en locale must be first!
+      `OPTIONAL {
+  ?s p ?o_en .
+  FILTER(LANG(?o_en) = "en")
+}
+OPTIONAL {
+  ?s p ?o_de .
+  FILTER(LANG(?o_de) = "de")
+}
+OPTIONAL {
+  ?s p ?o_fr .
+  FILTER(LANG(?o_fr) = "fr")
+}
+OPTIONAL {
+  ?s p ?o_it .
+  FILTER(LANG(?o_it) = "it")
+}
+OPTIONAL {
+  ?s p ?o_ .
+  FILTER(LANG(?o_) = "")
+}
+OPTIONAL {
+  ?s p ?o_raw .
+}
+BIND(COALESCE(?o_en, ?o_de, ?o_fr, ?o_it, ?o_, ?o_raw) AS ?o)`
+    );
+  });
+});
diff --git a/app/rdf/query-utils.ts b/app/rdf/query-utils.ts
index 635f06b12..3200e5519 100644
--- a/app/rdf/query-utils.ts
+++ b/app/rdf/query-utils.ts
@@ -24,16 +24,20 @@ export const buildLocalizedSubQuery = (
   return `${locales
     .map(
       (locale) => `OPTIONAL {
-          ?${s} ${p} ?${o}_${locale} .
-          FILTER(LANG(?${o}_${locale}) = "${locale}")
-        }`
+  ?${s} ${p} ?${o}_${locale} .
+  FILTER(LANG(?${o}_${locale}) = "${locale}")
+}`
     )
-    .join("\n")}
-    ${fallbackToNonLocalized ? `OPTIONAL { ?${s} ${p} ?${o}_raw }` : ""}
-      BIND(COALESCE(${locales.map((locale) => `?${o}_${locale}`).join(", ")} ${
+    .join("\n")}${
+    fallbackToNonLocalized
+      ? `\nOPTIONAL {
+  ?${s} ${p} ?${o}_raw .
+}`
+      : ""
+  }
+BIND(COALESCE(${locales.map((locale) => `?${o}_${locale}`).join(", ")}${
     fallbackToNonLocalized ? `, ?${o}_raw` : ``
-  }) AS ?${o})
-  `;
+  }) AS ?${o})`;
 };
 
 const getOrderedLocales = (locale: string) => {