From 67562dc2bb99578cec24572149631d73eec7b1aa Mon Sep 17 00:00:00 2001
From: Jonathan Lurie <lurie.jo@gmail.com>
Date: Wed, 6 Nov 2024 13:58:29 +0100
Subject: [PATCH] more robust language switching

---
 CHANGELOG.md  |  2 +-
 src/Map.ts    | 27 ++++++++++++++++-----------
 src/tools.ts  | 28 ++++++++++++++++++++++++++++
 tsconfig.json |  4 ++--
 4 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ac4a0e3..eccd094 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ## 2.4.2
 ### Bug Fixes
-- The language switching is now more robust and preserves the original formatting from the style (`Map.setPrimareyLangage()`) (https://github.com/maptiler/maptiler-sdk-js/pull/134)
+- The language switching is now more robust and preserves the original formatting from the style (`Map.setPrimaryLangage()`) (https://github.com/maptiler/maptiler-sdk-js/pull/134)
 
 ## 2.4.1
 ### Bug Fixes
diff --git a/src/Map.ts b/src/Map.ts
index 7485251..d182775 100644
--- a/src/Map.ts
+++ b/src/Map.ts
@@ -26,9 +26,11 @@ import { defaults } from "./defaults";
 import { MaptilerLogoControl } from "./MaptilerLogoControl";
 import {
   changeFirstLanguage,
+  checkNamePattern,
   combineTransformRequest,
   displayNoWebGlWarning,
   displayWebGLContextLostWarning,
+  replaceLanguage,
 } from "./tools";
 import { getBrowserLanguage, Language, type LanguageInfo } from "./language";
 import { styleToStyle } from "./mapstyle";
@@ -1127,19 +1129,22 @@ export class Map extends maplibregl.Map {
 
       // Testing the different case where the text-field property should NOT be updated:
       if (typeof textFieldLayoutProp === "string") {
-        // If the field is a string that DOES NOT contain an opening curly bracket.
-        // (This happens when the label is a hardcoded string that does not refer to a property)
-        if (!textFieldLayoutProp.includes("{")) {
-          continue;
-        }
+        const { contains, exactMatch } = checkNamePattern(textFieldLayoutProp);
 
-        // If the text field does not contain the "name" substring.
-        // This happens when dealing with {ref}, {housenumber}, {height}, etc.
-        if (!textFieldLayoutProp.includes("name")) {
-          continue;
-        }
+        // If the current text-fiels does not contain any "{name:xx}" pattern
+        if (!contains) continue;
 
-        this.setLayoutProperty(id, "text-field", replacer);
+        // In case of an exact match, we replace by an object representation of the label
+        if (exactMatch) {
+          this.setLayoutProperty(id, "text-field", replacer);
+        } else {
+          // In case of a non-exact match (such as "foo {name:xx} bar")
+          // we create a "concat" object expresion composed of the original elements with new replacer
+          // in-betweem
+          const newReplacer = replaceLanguage(textFieldLayoutProp, replacer);
+
+          this.setLayoutProperty(id, "text-field", newReplacer);
+        }
       }
 
       // The value of text-field is an object
diff --git a/src/tools.ts b/src/tools.ts
index 8f7be33..2acbc3d 100644
--- a/src/tools.ts
+++ b/src/tools.ts
@@ -268,3 +268,31 @@ export function changeFirstLanguage(
   exploreNode(expr);
   return expr;
 }
+
+/**
+ * Tst if a string matches the pattern "{name:xx}" in a exact way or is a loose way (such as "foo {name:xx}")
+ */
+export function checkNamePattern(str: string): { contains: boolean; exactMatch: boolean } {
+  const regex = /\{name:[a-zA-Z]{2}\}/;
+  return {
+    contains: regex.test(str),
+    exactMatch: new RegExp(`^${regex.source}$`).test(str),
+  };
+}
+
+/**
+ * Replaces the occurences of {name:xx} in a string by a provided object-expression to return a concat object expression
+ */
+export function replaceLanguage(
+  origLang: string,
+  newLang: maplibregl.ExpressionSpecification,
+): maplibregl.ExpressionSpecification {
+  const elementsToConcat = origLang.split(/\{name:[a-zA-Z]{2}\}/);
+
+  const allElements = elementsToConcat.flatMap((item, i) =>
+    i === elementsToConcat.length - 1 ? [item] : [item, newLang],
+  );
+
+  const expr = ["concat", ...allElements] as maplibregl.ExpressionSpecification;
+  return expr;
+}
diff --git a/tsconfig.json b/tsconfig.json
index 879d3bb..14e795f 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,10 +2,10 @@
   "compilerOptions": {
     "baseUrl": "src",
     "moduleResolution": "Node",
-    "target": "ES2020",
+    "target": "es2021",
     "useDefineForClassFields": true,
     "module": "ESNext",
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["es2021", "DOM", "DOM.Iterable"],
     "skipLibCheck": true,
 
     /* Bundler mode */