122357: Reduced the amount of times the browse observables are fired again

(cherry picked from commit 0570542b1e)

src/app/browse-by/browse-by-date-page/browse-by-date-page.component.ts

@@ -10,7 +10,7 @@ import { BrowseService } from '../../core/browse/browse.service';
 import { DSpaceObjectDataService } from '../../core/data/dspace-object-data.service';
 import { StartsWithType } from '../../shared/starts-with/starts-with-decorator';
 import { PaginationService } from '../../core/pagination/pagination.service';
-import { map, take } from 'rxjs/operators';
+import { map, distinctUntilChanged } from 'rxjs/operators';
 import { of as observableOf } from 'rxjs';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
 import { SortDirection, SortOptions } from '../../core/cache/models/sort-options.model';
@@ -61,16 +61,19 @@ export class BrowseByDatePageComponent extends BrowseByMetadataPageComponent {
     this.startsWithType = StartsWithType.date;
     this.currentPagination$ = this.paginationService.getCurrentPagination(this.paginationConfig.id, this.paginationConfig);
     this.currentSort$ = this.paginationService.getCurrentSort(this.paginationConfig.id, sortConfig);
+    const routeParams$: Observable<Params> = observableCombineLatest([
+      this.route.params,
+      this.route.queryParams,
+    ]).pipe(
+      map(([params, queryParams]: [Params, Params]) => Object.assign({}, params, queryParams)),
+      distinctUntilChanged((prev: Params, curr: Params) => prev.id === curr.id && prev.startsWith === curr.startsWith),
+    );
     this.subs.push(
-      observableCombineLatest(
+      observableCombineLatest([
-        [ this.route.params.pipe(take(1)),
+        routeParams$,
-          this.route.queryParams,
+        this.currentPagination$,
-          this.currentPagination$,
+        this.currentSort$,
-          this.currentSort$]).pipe(
+      ]).subscribe(([params, currentPage, currentSort]: [Params, PaginationComponentOptions, SortOptions]) => {
-        map(([routeParams, queryParams, currentPage, currentSort]) => {
-          return [Object.assign({}, routeParams, queryParams), currentPage, currentSort];
-        })
-      ).subscribe(([params, currentPage, currentSort]: [Params, PaginationComponentOptions, SortOptions]) => {
         const metadataKeys = params.browseDefinition ? params.browseDefinition.metadataKeys : this.defaultMetadataKeys;
         this.browseId = params.id || this.defaultBrowseId;
         this.startsWith = +params.startsWith || params.startsWith;

src/app/browse-by/browse-by-metadata-page/browse-by-metadata-page.component.ts

@@ -15,7 +15,7 @@ import { DSpaceObjectDataService } from '../../core/data/dspace-object-data.serv
 import { DSpaceObject } from '../../core/shared/dspace-object.model';
 import { StartsWithType } from '../../shared/starts-with/starts-with-decorator';
 import { PaginationService } from '../../core/pagination/pagination.service';
-import { filter, map, mergeMap, take } from 'rxjs/operators';
+import { filter, map, mergeMap, distinctUntilChanged } from 'rxjs/operators';
 import { followLink, FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { Bitstream } from '../../core/shared/bitstream.model';
 import { Collection } from '../../core/shared/collection.model';
@@ -162,20 +162,22 @@ export class BrowseByMetadataPageComponent implements OnInit, OnDestroy {
       return;
     }
     const sortConfig = new SortOptions('default', SortDirection.ASC);
-    this.updatePage(getBrowseSearchOptions(this.defaultBrowseId, this.paginationConfig, sortConfig));
     this.currentPagination$ = this.paginationService.getCurrentPagination(this.paginationConfig.id, this.paginationConfig);
     this.currentSort$ = this.paginationService.getCurrentSort(this.paginationConfig.id, sortConfig);
+    const routeParams$: Observable<Params> = observableCombineLatest([
+      this.route.params,
+      this.route.queryParams,
+    ]).pipe(
+      map(([params, queryParams]: [Params, Params]) => Object.assign({}, params, queryParams)),
+      distinctUntilChanged((prev: Params, curr: Params) => prev.id === curr.id && prev.authority === curr.authority && prev.value === curr.value && prev.startsWith === curr.startsWith),
+    );
     this.subs.push(
-      observableCombineLatest(
+      observableCombineLatest([
-        [ this.route.params.pipe(take(1)),
+        routeParams$,
-          this.route.queryParams,
+        this.currentPagination$,
-          this.currentPagination$,
+        this.currentSort$,
-          this.currentSort$]).pipe(
+      ]).subscribe(([params, currentPage, currentSort]: [Params, PaginationComponentOptions, SortOptions]) => {
-        map(([routeParams, queryParams, currentPage, currentSort]) => {
+        this.browseId = params.id || this.defaultBrowseId;
-          return [Object.assign({}, routeParams, queryParams),currentPage,currentSort];
-        })
-      ).subscribe(([params, currentPage, currentSort]: [Params, PaginationComponentOptions, SortOptions]) => {
-          this.browseId = params.id || this.defaultBrowseId;
           this.authority = params.authority;
 
           if (typeof params.value === 'string'){

src/app/browse-by/browse-by-title-page/browse-by-title-page.component.ts

@@ -1,4 +1,4 @@
-import { combineLatest as observableCombineLatest } from 'rxjs';
+import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 import { Component, Inject, PLATFORM_ID } from '@angular/core';
 import { ActivatedRoute, Params, Router } from '@angular/router';
 import { hasValue } from '../../shared/empty.util';
@@ -10,7 +10,7 @@ import { DSpaceObjectDataService } from '../../core/data/dspace-object-data.serv
 import { BrowseService } from '../../core/browse/browse.service';
 import { SortDirection, SortOptions } from '../../core/cache/models/sort-options.model';
 import { PaginationService } from '../../core/pagination/pagination.service';
-import { map, take } from 'rxjs/operators';
+import { map, distinctUntilChanged } from 'rxjs/operators';
 import { of as observableOf } from 'rxjs';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
 import { AppConfig, APP_CONFIG } from '../../../config/app-config.interface';
@@ -48,12 +48,19 @@ export class BrowseByTitlePageComponent extends BrowseByMetadataPageComponent {
     const sortConfig = new SortOptions('dc.title', SortDirection.ASC);
     this.currentPagination$ = this.paginationService.getCurrentPagination(this.paginationConfig.id, this.paginationConfig);
     this.currentSort$ = this.paginationService.getCurrentSort(this.paginationConfig.id, sortConfig);
+    const routeParams$: Observable<Params> = observableCombineLatest([
+      this.route.params,
+      this.route.queryParams,
+    ]).pipe(
+      map(([params, queryParams]: [Params, Params]) => Object.assign({}, params, queryParams)),
+      distinctUntilChanged((prev: Params, curr: Params) => prev.id === curr.id && prev.startsWith === curr.startsWith),
+    );
     this.subs.push(
-      observableCombineLatest([this.route.params.pipe(take(1)), this.route.queryParams, this.currentPagination$, this.currentSort$]).pipe(
+      observableCombineLatest([
-        map(([routeParams, queryParams, currentPage, currentSort]) => {
+        routeParams$,
-          return [Object.assign({}, routeParams, queryParams),currentPage,currentSort];
+        this.currentPagination$,
-        })
+        this.currentSort$,
-      ).subscribe(([params, currentPage, currentSort]: [Params, PaginationComponentOptions, SortOptions]) => {
+      ]).subscribe(([params, currentPage, currentSort]: [Params, PaginationComponentOptions, SortOptions]) => {
         this.startsWith = +params.startsWith || params.startsWith;
         this.browseId = params.id || this.defaultBrowseId;
         this.updatePageWithItems(browseParamsToOptions(params, currentPage, currentSort, this.browseId, this.fetchThumbnails), undefined, undefined);