adapted remote data build method to aggregate relation remotedata arrays

src/app/core/shared/item.model.ts

@@ -31,14 +31,14 @@ export class Item extends DSpaceObject {
     /**
      * An array of Collections that are direct parents of this Item
      */
-    parents: Array<RemoteData<Collection>>;
+    parents: RemoteData<Collection[]>;
 
     /**
      * The Collection that owns this Item
      */
     owner: Collection;
 
-    bundles: Array<RemoteData<Bundle>>;
+    bundles: RemoteData<Bundle[]>;
 
 
     /**
@@ -63,13 +63,11 @@ export class Item extends DSpaceObject {
      * Retrieves all files that should be displayed on the item page of this item
      * @returns {Observable<Array<Observable<Bitstream>>>} an array of all Bitstreams in the "ORIGINAL" bundle
      */
-    getFiles(): Observable<Array<Observable<Bitstream>>> {
+    getFiles(): Observable<Bitstream[]> {
         const bundle: Observable <Bundle> = this.getBundle("ORIGINAL");
-        return bundle.map(bundle => {
-            if (hasValue(bundle) && Array.isArray(bundle.bitstreams)) {
-                return bundle.bitstreams.map(bitstream => bitstream.payload)
-            }
-        });
+        return bundle
+          .filter(bundle => hasValue(bundle))
+          .flatMap(bundle => bundle.bitstreams.payload);
     }
 
     /**
@@ -78,9 +76,8 @@ export class Item extends DSpaceObject {
      * @returns {Observable<Bundle>} the Bundle that belongs to this item with the given name
      */
     getBundle(name: String): Observable<Bundle> {
-        return Observable.combineLatest(
-            ...this.bundles.map(b => b.payload),
-            (...bundles: Array<Bundle>) => bundles)
+        return this.bundles.payload
+            .filter(bundles => hasValue(bundles))
             .map(bundles => {
                 return bundles.find((bundle: Bundle) => {
                     return bundle.name === name
@@ -88,12 +85,4 @@ export class Item extends DSpaceObject {
             });
     }
 
-    /**
-     * Retrieves all direct parent collections of this item
-     * @returns {Array<Observable<Collection>>} an array of all Collections that contain this item
-     */
-    getCollections(): Array<Observable<Collection>> {
-        return this.parents.map(collection => collection.payload.map(parent => parent));
-    }
-
 }