refactor: avoid errors in daia availability UI

src/app/modules/hebis/daia-availability/daia-availability.component.ts

@@ -35,7 +35,7 @@ export class DaiaAvailabilityComponent
   extends DataDetailComponent
   implements OnInit
 {
-  holdings: SCDaiaHoldings[];
+  holdings: SCDaiaHoldings[] | undefined;
 
   /**
    *
@@ -68,8 +68,10 @@ export class DaiaAvailabilityComponent
    * Initialize
    */
   async ngOnInit() {
-    const uid = this.route.snapshot.paramMap.get('uid') || '';
-    await this.getAvailability(uid ?? '');
+    const uid = this.route.snapshot.paramMap.get('uid');
+    if (uid) {
+      await this.getAvailability(uid);
+    }
   }
 
   /**

src/app/modules/hebis/daia-availability/daia-availability.html

@@ -1,14 +1,14 @@
 <ion-card>
-  <ion-card-header>{{
-    'hebisSearch.daia.availability' | translate
-  }}</ion-card-header>
+  <ion-card-header>
+    {{ 'hebisSearch.daia.availability' | translate }}
+  </ion-card-header>
   <ion-card-content>
     <ng-container *ngFor="let holding of holdings">
-      <ion-label
-        ><a [href]="holding.href" target="_blank">{{
-          holding.label
-        }}</a></ion-label
-      >
+      <ion-label>
+        <a [href]="holding.href" target="_blank">
+          {{ holding.label }}
+        </a>
+      </ion-label>
       <ion-grid>
         <ion-row *ngIf="holding.signature">
           <ion-col size="3">{{
@@ -23,7 +23,7 @@
             "
             >{{ holding.signature }}</ion-col
           >
-          <ion-col size="9" *ngIf="holding.available.service === 'openaccess'">
+          <ion-col size="9" *ngIf="holding.available?.service === 'openaccess'">
             <a [href]="holding.available.href" target="_blank">{{
               'hebisSearch.daia.ejournal' | translate
             }}</a>
@@ -59,5 +59,11 @@
         </ion-row>
       </ion-grid>
     </ng-container>
+    <ion-label *ngIf="!holdings">
+      {{ 'hebisSearch.daia.unavailableAvailability' | translate }}
+    </ion-label>
+    <ion-label *ngIf="holdings?.length === 0">
+      {{ 'hebisSearch.daia.unknownAvailability' | translate }}
+    </ion-label>
   </ion-card-content>
 </ion-card>

src/app/modules/hebis/daia-data.provider.ts

@@ -51,7 +51,8 @@ export class DaiaDataProvider extends DataProvider {
    * @param stAppsWebHttpClient TODO
    * @param storageProvider TODO
    * @param httpClient TODO
-   * @param ConfigProvider TODO
+   * @param configProvider TODO
+   * @param logger TODO
    */
   constructor(
     stAppsWebHttpClient: StAppsWebHttpClient,
@@ -71,7 +72,7 @@ export class DaiaDataProvider extends DataProvider {
     );
   }
 
-  async getAvailability(id: string): Promise<SCDaiaHoldings[]> {
+  async getAvailability(id: string): Promise<SCDaiaHoldings[] | undefined> {
     if (this.backendUrl === environment.backend_url) {
       try {
         const features = (await this.configProvider.getValue(
@@ -81,11 +82,11 @@ export class DaiaDataProvider extends DataProvider {
           this.backendUrl = features.extern?.daia?.url;
         } else {
           this.logger.error('Daia service url undefined');
-          return [];
+          return undefined;
         }
       } catch (error) {
         this.logger.error(error);
-        return [];
+        return undefined;
       }
     }
     return new Promise(resolve =>
@@ -143,7 +144,8 @@ export class DaiaDataProvider extends DataProvider {
           },
           error => {
             this.logger.error(error);
-            resolve([]);
+            // eslint-disable-next-line unicorn/no-useless-undefined
+            resolve(undefined);
           },
         ),
     );

src/assets/i18n/de.json

@@ -274,7 +274,9 @@
       "comment": "Kommentar",
       "order": "Bestellen",
       "issn": "ISSN",
-      "ejournal": "ejournal"
+      "ejournal": "ejournal",
+      "unknownAvailability": "Keine Information vorhanden",
+      "unavailableAvailability": "System nicht erreichbar"
     }
   },
   "schedule": {

src/assets/i18n/en.json

@@ -274,7 +274,9 @@
       "comment": "Remark",
       "order": "Request",
       "issn": "ISSN",
-      "ejournal": "ejournal"
+      "ejournal": "ejournal",
+      "unknownAvailability": "No information available",
+      "unavailableAvailability": "System unreachable"
     }
   },
   "schedule": {