Added search filter optimalisations

src/app/+search-page/search-filters/search-filter/search-boolean-filter/search-boolean-filter.component.html

@@ -8,7 +8,7 @@
         </a>
       <ng-container *ngFor="let page of (filterValues$ | async)?.payload">
         <div [@facetLoad]="animationState">
-          <ng-container *ngFor="let value of page.page; let i=index">
+          <ng-container *ngFor="let value of page.page; trackBy: trackUpdate">
                 <a *ngIf="!(selectedValues | async).includes(value.value)" class="d-flex flex-row"
                    [routerLink]="[getSearchLink()]"
                    [queryParams]="getAddParams(value.value) | async" queryParamsHandling="merge">

src/app/+search-page/search-filters/search-filter/search-facet-filter/search-facet-filter.component.ts

@@ -290,6 +290,14 @@ export class SearchFacetFilterComponent implements OnInit, OnDestroy {
   getDisplayValue(facet: FacetValue, query: string): string {
     return new EmphasizePipe().transform(facet.value, query) + ' (' + facet.count + ')';
   }
+
+
+  /**
+   * Prevent unnecessary rerendering
+   */
+  trackUpdate(index, value: FacetValue) {
+    return value ? value.search : undefined;
+  }
 }
 
 export const facetLoad = trigger('facetLoad', [

src/app/+search-page/search-filters/search-filter/search-filter.service.ts

 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 import { Injectable, InjectionToken } from '@angular/core';
-import { map } from 'rxjs/operators';
+import { distinctUntilChanged, map } from 'rxjs/operators';
 import { SearchFiltersState, SearchFilterState } from './search-filter.reducer';
 import { createSelector, MemoizedSelector, select, Store } from '@ngrx/store';
 import {
@@ -65,7 +65,9 @@ export class SearchFilterService {
 
     return observableCombineLatest(values$, prefixValues$).pipe(
       map(([values, prefixValues]) => {
-          if (isNotEmpty(values)) {
+        console.log('getSelectedValuesForFilter ', values, prefixValues);
+
+        if (isNotEmpty(values)) {
             return values;
           }
           return prefixValues;
@@ -88,13 +90,14 @@ export class SearchFilterService {
         } else {
           return false;
         }
-      })
+      }),
+      distinctUntilChanged()
     );
   }
 
   /**
    * Request the current page of a given filter
-   * @param {string} filterName The filtername for which the page state is checked
+   * @param {string} filterName The filter name for which the page state is checked
    * @returns {Observable<boolean>} Emits the current page state of the given filter, if it's unavailable, return 1
    */
   getPage(filterName: string): Observable<number> {
@@ -106,7 +109,8 @@ export class SearchFilterService {
         } else {
           return 1;
         }
-      }));
+      }),
+      distinctUntilChanged());
   }
 
   /**

src/app/+search-page/search-filters/search-filter/search-hierarchy-filter/search-hierarchy-filter.component.html

@@ -8,7 +8,7 @@
         </a>
         <ng-container *ngFor="let page of (filterValues$ | async)?.payload">
           <div [@facetLoad]="animationState">
-            <ng-container *ngFor="let value of page.page; let i=index">
+            <ng-container *ngFor="let value of page.page; trackBy: trackUpdate">
                 <a *ngIf="!(selectedValues | async).includes(value.value)" class="d-flex flex-row"
                    [routerLink]="[getSearchLink()]"
                    [queryParams]="getAddParams(value.value) | async" queryParamsHandling="merge" >

src/app/+search-page/search-filters/search-filter/search-range-filter/search-range-filter.component.html

@@ -24,7 +24,7 @@
         </ng-container>
       <ng-container *ngFor="let page of (filterValues$ | async)?.payload">
         <div [@facetLoad]="animationState">
-          <ng-container *ngFor="let value of page.page; let i=index">
+          <ng-container *ngFor="let value of page.page; trackBy: trackUpdate">
                 <a *ngIf="!(selectedValues | async).includes(value.value)" class="d-flex flex-row"
                    [routerLink]="[getSearchLink()]"
                    [queryParams]="getChangeParams(value.value) | async" queryParamsHandling="merge">

src/app/+search-page/search-filters/search-filter/search-text-filter/search-text-filter.component.html

@@ -9,7 +9,7 @@
         <ng-container *ngVar="(filterValues$ | async) as filterValuesRD">
           <div [@facetLoad]="animationState">
             <ng-container *ngFor="let page of filterValuesRD?.payload">
-              <ng-container *ngFor="let value of page.page; let i=index">
+              <ng-container *ngFor="let value of page.page; trackBy: trackUpdate">
                 <a *ngIf="!(selectedValues | async).includes(value.value)" class="d-flex flex-row"
                    [routerLink]="[getSearchLink()]"
                    [queryParams]="getAddParams(value.value) | async" queryParamsHandling="merge" >

src/app/+search-page/search-filters/search-filters.component.html

 <h3>{{"search.filters.head" | translate}}</h3>
 <div *ngIf="(filters | async)?.hasSucceeded">
-    <div *ngFor="let filter of (filters | async)?.payload">
+    <div *ngFor="let filter of (filters | async)?.payload; trackBy: trackUpdate">
         <ds-search-filter *ngIf="isActive(filter) | async" class="d-block mb-3 p-3" [filter]="filter"></ds-search-filter>
     </div>
 </div>

src/app/+search-page/search-filters/search-filters.component.ts

 import { Observable, of as observableOf } from 'rxjs';
 
-import { filter, map, mergeMap, startWith, switchMap } from 'rxjs/operators';
+import { filter, first, map, mergeMap, startWith, switchMap, tap } from 'rxjs/operators';
 import { Component } from '@angular/core';
 import { SearchService } from '../search-service/search.service';
 import { RemoteData } from '../../core/data/remote-data';
@@ -9,6 +9,7 @@ import { SearchConfigurationService } from '../search-service/search-configurati
 import { isNotEmpty } from '../../shared/empty.util';
 import { SearchFilterService } from './search-filter/search-filter.service';
 import { getSucceededRemoteData } from '../../core/shared/operators';
+import { FieldUpdate } from '../../core/data/object-updates/object-updates.reducer';
 
 @Component({
   selector: 'ds-search-filters',
@@ -59,11 +60,13 @@ export class SearchFiltersComponent {
    */
   isActive(filterConfig: SearchFilterConfig): Observable<boolean> {
     return this.filterService.getSelectedValuesForFilter(filterConfig).pipe(
-      mergeMap((isActive) => {
+      switchMap((isActive) => {
+        console.log('selected fires');
         if (isNotEmpty(isActive)) {
           return observableOf(true);
         } else {
           return this.searchConfigService.searchOptions.pipe(
+            first(),
             switchMap((options) => {
                 return this.searchService.getFacetValuesFor(filterConfig, 1, options).pipe(
                   filter((RD) => !RD.isLoading),
@@ -73,6 +76,13 @@ export class SearchFiltersComponent {
               }
             ))
         }
-      }),startWith(true),);
+      }), tap(t => console.log(t)), startWith(true));
+  }
+
+  /**
+   * Prevent unnecessary rerendering
+   */
+  trackUpdate(index, config: SearchFilterConfig) {
+    return config ? config.name : undefined;
   }
 }

src/app/shared/services/route.service.ts

@@ -16,7 +16,7 @@ export class RouteService {
   getQueryParameterValues(paramName: string): Observable<string[]> {
     return this.route.queryParamMap.pipe(
       map((params) => [...params.getAll(paramName)]),
-      distinctUntilChanged()
+      distinctUntilChanged((a, b) => JSON.stringify(a) === JSON.stringify(b))
     );
   }