[DSC-2279] implement possibility to negate filter in

Author: FrancescoMolinaro

src/app/core/shared/metadata.models.ts

@@ -96,6 +96,10 @@ export interface MetadataValueFilter {
 
   /** Whether the value constraint should match as a substring. */
   substring?: boolean;
+  /**
+   * Whether to negate the filter
+   */
+  negate?: boolean;
 }
 
 export class MetadatumViewModel {

src/app/core/shared/metadata.utils.ts

@@ -14,7 +14,7 @@ import { validate as uuidValidate } from 'uuid';
 
 export const AUTHORITY_GENERATE = 'will be generated::';
 export const AUTHORITY_REFERENCE = 'will be referenced::';
-
+export const PLACEHOLDER_VALUE = '#PLACEHOLDER_PARENT_METADATA_VALUE#';
 /**
  * Utility class for working with DSpace object metadata.
  *
@@ -178,15 +178,19 @@ export class Metadata {
     } else if (filter.value) {
       let fValue = filter.value;
       let mValue = mdValue.value;
+
       if (filter.ignoreCase) {
         fValue = filter.value.toLowerCase();
         mValue = mdValue.value.toLowerCase();
       }
+      let result;
+
       if (filter.substring) {
-        return mValue.includes(fValue);
+        result = mValue.includes(fValue);
       } else {
-        return mValue === fValue;
+        result = mValue === fValue;
       }
+      return filter.negate ? !result : result;
     }
     return true;
   }

src/app/shared/object-list/search-result-list-element/item-search-result/item-types/item/item-search-result-list-element.component.html

@@ -38,15 +38,15 @@
                 <span *ngIf="dso.firstMetadataValue('dc.date.issued')" class="item-list-date"
                       [innerHTML]="firstMetadataValue('dc.date.issued')"></span>)
               </ng-container>
-              <span *ngIf="dso.allMetadataValues(authorMetadata).length > 0" class="item-list-authors">
+              <span *ngIf="dso.allMetadataValues(authorMetadata, placeholderFilter).length > 0" class="item-list-authors">
                 <ng-container *ngVar="(isCollapsed() | async) as isCollapsed">
                   <ng-container *ngIf="isCollapsed">
-                    <span *ngFor="let author of dso.limitedMetadata(authorMetadata, additionalMetadataLimit); let i=index; let last=last;">
+                    <span *ngFor="let author of dso.limitedMetadata(authorMetadata, additionalMetadataLimit, placeholderFilter); let i=index; let last=last;">
                       <ds-metadata-link-view [item]="dso" [metadata]="author" [metadataName]="authorMetadata"></ds-metadata-link-view><span *ngIf="!last">; </span>
                     </span>
                   </ng-container>
                   <ng-container *ngIf="!isCollapsed">
-                     <span *ngFor="let author of dso.allMetadata(authorMetadata); let i=index; let last=last;">
+                     <span *ngFor="let author of dso.allMetadata(authorMetadata, placeholderFilter); let i=index; let last=last;">
                       <ds-metadata-link-view [item]="dso" [metadata]="author" [metadataName]="authorMetadata"></ds-metadata-link-view><span *ngIf="!last">; </span>
                     </span>
                   </ng-container>

src/app/shared/object-list/search-result-list-element/item-search-result/item-types/item/item-search-result-list-element.component.ts

@@ -18,6 +18,8 @@ import { getFirstSucceededRemoteListPayload } from '../../../../../../core/share
 import { differenceInDays, differenceInMilliseconds, parseISO} from 'date-fns';
 import { filter, map } from 'rxjs/operators';
 import { isNotEmpty } from '../../../../../empty.util';
+import { MetadataValueFilter } from '../../../../../../core/shared/metadata.models';
+import { PLACEHOLDER_VALUE } from '../../../../../../core/shared/metadata.utils';
 
 @listableObjectComponent('PublicationSearchResult', ViewMode.ListElement)
 @listableObjectComponent(ItemSearchResult, ViewMode.ListElement)
@@ -46,6 +48,11 @@ export class ItemSearchResultListElementComponent extends SearchResultListElemen
 
   hasLoadedThirdPartyMetrics$: Observable<boolean>;
 
+  readonly placeholderFilter: MetadataValueFilter = {
+    negate: true,
+    value: PLACEHOLDER_VALUE
+  };
+
   private thirdPartyMetrics = environment.info.metricsConsents.filter(metric => metric.enabled).map(metric => metric.key);