add style strict

frontend/src/main.ts

@@ -19,6 +19,7 @@ const api : ControllerAPI = new ControllerAPI();
 async function authInit() {
     console.log("User is authenticated");
     const newsFeed = await api.getNews(true) as NewsFeed;
+    newsFeed.style = currentStyle;
     const appElement = document.getElementById("app");
     if (appElement)
         appElement.innerHTML = newsFeed.build();

frontend/src/pages/default-element.ts

@@ -6,4 +6,9 @@ export abstract class DefaultElement extends GefestElement {
     constructor(content: (GefestElement | string)[] | string) {
         super(content);
     }
+
+    build(isFromStyle?: boolean): string {
+        if (!this.style) throw new Error("Setup style is required");
+        return super.build(isFromStyle);
+    }
 }