Fixed issue with syntax highlighting in code editor (#19414)

* Fixed issue with syntax highlighting in code editor.

* Update src/Umbraco.Web.UI.Client/src/packages/code-editor/property-editor/property-editor-ui-code-editor.element.ts

Co-authored-by: Copilot <[email protected]>

* Refactor introducing helper method.

---------

Co-authored-by: Copilot <[email protected]>
Co-authored-by: Jacob Overgaard <[email protected]>

Author: 3 people

src/Umbraco.Web.UI.Client/src/packages/code-editor/property-editor/property-editor-ui-code-editor.element.ts

@@ -38,13 +38,20 @@ export class UmbPropertyEditorUICodeEditorElement extends UmbLitElement implemen
 	public set config(config: UmbPropertyEditorConfigCollection | undefined) {
 		if (!config) return;
 
-		this._language = config?.getValueByAlias<CodeEditorLanguage>('language') ?? this.#defaultLanguage;
+		this._language = this.#getConfiguredLanguage(config);
 		this._height = Number(config?.getValueByAlias('height')) || 400;
 		this._lineNumbers = config?.getValueByAlias('lineNumbers') ?? false;
 		this._minimap = config?.getValueByAlias('minimap') ?? false;
 		this._wordWrap = config?.getValueByAlias('wordWrap') ?? false;
 	}
 
+	#getConfiguredLanguage(config: UmbPropertyEditorConfigCollection) {
+		const configuredLanguage = config?.getValueByAlias<CodeEditorLanguage>('language') ?? this.#defaultLanguage;
+		return Array.isArray(configuredLanguage)
+			? (configuredLanguage.length > 0 ? configuredLanguage[0] : this.#defaultLanguage)
+			: configuredLanguage;
+	}
+
 	#onChange(event: UmbInputEvent & { target: UmbCodeEditorElement }) {
 		if (!(event instanceof UmbInputEvent)) return;
 		this.value = event.target.code;