fix issue #309, race condition of getResourceAsync

Author: adileo

CHANGELOG.md

@@ -13,6 +13,7 @@ This changelog covers all three packages, as they are (for now) updated as a who
 - Add new file preview types to the folder grid view.
 - Add `store.preloadClassesAndProperties` and remove `urls.properties.getAll` and `urls.classes.getAll`. This enables using `atomic-data-browser` without relying on `atomicdata.dev` being available.
 - Fix Dialogue form #308
+- Fix Race condition of `store.getResourceAsync` #309
 
 ## v0.35.0
 

lib/src/store.ts

@@ -322,10 +322,33 @@ export class Store {
   public async getResourceAsync(subject: string): Promise<Resource> {
     const found = this.resources.get(subject);
 
-    if (found) {
+    if (found && found.isReady()) {
       return found;
     }
 
+    /** Fix the case where a resource was previously requested but still not ready */
+    if (found && !found.isReady()) {
+      return new Promise((resolve, reject) => {
+        const defaultTimeout = 5000;
+
+        const cb = res => {
+          this.unsubscribe(subject, cb);
+          resolve(res);
+        };
+
+        this.subscribe(subject, cb);
+
+        setTimeout(() => {
+          this.unsubscribe(subject, cb);
+          reject(
+            new Error(
+              `Async Request for subject "${subject}" timed out after ${defaultTimeout}ms.`,
+            ),
+          );
+        }, defaultTimeout);
+      });
+    }
+
     return this.fetchResourceFromServer(subject);
   }