first tests and docs

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

@@ -4,6 +4,7 @@ import { RemoteData } from "../data/remote-data";
 import { Bundle } from "./bundle.model";
 import { Bitstream } from "./bitstream.model";
 import { Observable } from "rxjs";
+import { hasValue } from "../../shared/empty.util";
 
 export class Item extends DSpaceObject {
 
@@ -39,6 +40,11 @@ export class Item extends DSpaceObject {
 
     bundles: Array<RemoteData<Bundle>>;
 
+
+    /**
+     * Retrieves the thumbnail of this item
+     * @returns {Observable<Bitstream>} the primaryBitstream of the "THUMBNAIL" bundle
+     */
     getThumbnail(): Observable<Bitstream> {
         const bundle: Observable<Bundle> = this.getBundle("THUMBNAIL");
         return bundle.flatMap(
@@ -53,15 +59,24 @@ 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>>> {
         const bundle: Observable <Bundle> = this.getBundle("ORIGINAL");
         return bundle.map(bundle => {
-            if (bundle != null) {
+            if (hasValue(bundle) && Array.isArray(bundle.bitstreams)) {
                 return bundle.bitstreams.map(bitstream => bitstream.payload)
             }
         });
     }
 
+    /**
+     * Retrieves the bundle of this item by its name
+     * @param name The name of the Bundle that should be returned
+     * @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),
@@ -73,6 +88,10 @@ 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));
     }