initial

frontend/app/API.ts

@@ -0,0 +1,81 @@
+import type { DataType, DataTypeConfiguration } from "./types";
+
+enum APIMethod {
+  GET = "GET",
+  POST = "POST",
+  PUT = "PUT",
+  DELETE = "DELETE",
+}
+
+export class API {
+  private readonly apiBaseUrl: string;
+
+  constructor(apiBaseUrl: string) {
+    this.apiBaseUrl = apiBaseUrl;
+  }
+
+  readConfiguration(): Promise<DataTypeConfiguration> {
+    return this.call(APIMethod.GET, "/data");
+  }
+
+  readDataType(id: string): Promise<DataType> {
+    return this.call(APIMethod.GET, "/data/" + id);
+  }
+
+  deleteDataType(type: DataType): Promise<void> {
+    return this.call(APIMethod.DELETE, "/data/" + type.id);
+  }
+
+  saveDataType(type: DataType): Promise<DataTypeConfiguration> {
+    return this.call(APIMethod.POST, "/data", type);
+  }
+
+  /* 
+    Helper methods
+  */
+  private fullUrl(url: string): string {
+    return this.apiBaseUrl + url;
+  }
+
+  private requestOptions<A>(method: APIMethod, obj?: A): RequestInit {
+    const headers: HeadersInit = new Headers();
+    const options: RequestInit = {
+      method: method,
+      headers: headers,
+    };
+    if (obj !== undefined) {
+      const objType = typeof obj;
+      if (objType === "object") {
+        options.body = JSON.stringify(obj);
+        headers.set("Content-Type", "application/json; charset=UTF-8");
+      } else {
+        throw new Error("Unsupported type: " + objType);
+      }
+    }
+    return options;
+  }
+
+  private async call<T, A>(
+    method: APIMethod,
+    url: string,
+    obj?: A
+  ): Promise<T> {
+    const options = this.requestOptions(method, obj);
+    const response = await fetch(this.fullUrl(url), options);
+    const status = response.status;
+    const ok = status >= 200 && status < 400;
+    if (ok) {
+      return await response.json();
+    } else {
+      const errorText = await response.text();
+      return Promise.reject(errorText);
+    }
+  }
+
+  static instance(): API {
+    const runtimeConfig = useRuntimeConfig();
+    // See the `nuxt.config.ts` file
+    const apiBaseUrl = runtimeConfig.public.backend.baseUrl;
+    return new API(apiBaseUrl);
+  }
+}