fix(template-outlet): memory leak for cached templates

projects/igniteui-angular/src/lib/directives/template-outlet/template_outlet.directive.ts

@@ -1,6 +1,7 @@
 import {
     Directive, EmbeddedViewRef, Input, OnChanges, ChangeDetectorRef,
-    SimpleChange, SimpleChanges, TemplateRef, ViewContainerRef, NgZone, Output, EventEmitter
+    SimpleChange, SimpleChanges, TemplateRef, ViewContainerRef, NgZone, Output, EventEmitter,
+    OnDestroy,
 } from '@angular/core';
 
 import { IBaseEventArgs } from '../../core/utils';
@@ -12,7 +13,7 @@ import { IBaseEventArgs } from '../../core/utils';
     selector: '[igxTemplateOutlet]',
     standalone: true
 })
-export class IgxTemplateOutletDirective implements OnChanges {
+export class IgxTemplateOutletDirective implements OnChanges, OnDestroy {
     @Input() public igxTemplateOutletContext !: any;
 
     @Input() public igxTemplateOutlet !: TemplateRef<any>;
@@ -51,6 +52,10 @@ export class IgxTemplateOutletDirective implements OnChanges {
         }
     }
 
+    public ngOnDestroy(): void {
+        this.cleanCache();
+    }
+
     public cleanCache() {
         this._embeddedViewsMap.forEach((collection) => {
             collection.forEach((item => {
@@ -63,15 +68,6 @@ export class IgxTemplateOutletDirective implements OnChanges {
         this._embeddedViewsMap.clear();
     }
 
-    public cleanView(tmplID) {
-        const embViewCollection = this._embeddedViewsMap.get(tmplID.type);
-        const embView = embViewCollection?.get(tmplID.id);
-        if (embView) {
-            embView.destroy();
-            this._embeddedViewsMap.get(tmplID.type).delete(tmplID.id);
-        }
-    }
-
     private _recreateView() {
         const prevIndex = this._viewRef ? this._viewContainerRef.indexOf(this._viewRef) : -1;
         // detach old and create new
@@ -88,12 +84,7 @@ export class IgxTemplateOutletDirective implements OnChanges {
                 // if context contains a template id, check if we have a view for that template already stored in the cache
                 // if not create a copy and add it to the cache in detached state.
                 // Note: Views in detached state do not appear in the DOM, however they remain stored in memory.
-                const resCollection = this._embeddedViewsMap.get(this.igxTemplateOutletContext['templateID'].type);
-                const res = resCollection?.get(this.igxTemplateOutletContext['templateID'].id);
-                if (!res) {
-                    this._embeddedViewsMap.set(this.igxTemplateOutletContext['templateID'].type,
-                        new Map([[this.igxTemplateOutletContext['templateID'].id, this._viewRef]]));
-                }
+                this.cacheView(tmplId, this._viewRef);
             }
         }
     }
@@ -105,7 +96,7 @@ export class IgxTemplateOutletDirective implements OnChanges {
         if (view !== this._viewRef) {
             if (owner._viewContainerRef.indexOf(view) !== -1) {
                 // detach in case view it is attached somewhere else at the moment.
-                this.beforeViewDetach.emit({ owner: this, view: this._viewRef, context: this.igxTemplateOutletContext });
+                this.beforeViewDetach.emit({ owner: this, view, context: this.igxTemplateOutletContext });
                 owner._viewContainerRef.detach(owner._viewContainerRef.indexOf(view));
             }
             if (this._viewRef && this._viewContainerRef.indexOf(this._viewRef) !== -1) {
@@ -197,6 +188,26 @@ export class IgxTemplateOutletDirective implements OnChanges {
             return TemplateOutletAction.UpdateViewContext;
         }
     }
+
+    private cacheView(tmplID: { type: string, id: unknown } | undefined, viewRef: EmbeddedViewRef<any>) {
+        if (!tmplID) {
+            return;
+        }
+
+        const hasUniqueId = tmplID.id !== undefined && tmplID.id !== null;
+        if (hasUniqueId) {
+            // Don't cache locally unique id views, they're handled by the parent component by using moveview instead of cache
+            return;
+        }
+
+        let resCollection = this._embeddedViewsMap.get(tmplID.type);
+        if (!resCollection) {
+            resCollection = new Map();
+            this._embeddedViewsMap.set(tmplID.type, resCollection);
+        }
+
+        resCollection.set(tmplID.id, viewRef);
+    }
 }
 enum TemplateOutletAction {
     CreateView,

projects/igniteui-angular/src/lib/grids/grid-base.directive.ts

@@ -71,7 +71,7 @@ import { IgxGridSummaryService } from './summaries/grid-summary.service';
 import { IgxSummaryRowComponent } from './summaries/summary-row.component';
 import { IgxGridSelectionService } from './selection/selection.service';
 import { IgxEditRow, IgxCell } from './common/crud.service';
-import { ICachedViewLoadedEventArgs, IgxTemplateOutletDirective } from '../directives/template-outlet/template_outlet.directive';
+import { ICachedViewLoadedEventArgs } from '../directives/template-outlet/template_outlet.directive';
 import { IgxExcelStyleLoadingValuesTemplateDirective } from './filtering/excel-style/excel-style-search.component';
 import { IgxGridColumnResizerComponent } from './resizing/resizer.component';
 import { CharSeparatedValueData } from '../services/csv/char-separated-value-data';
@@ -1370,12 +1370,6 @@ export abstract class IgxGridBaseDirective implements GridType,
     @ViewChild('igxRowEditingOverlayOutlet', { read: IgxOverlayOutletDirective, static: true })
     public rowEditingOutletDirective: IgxOverlayOutletDirective;
 
-    /**
-     * @hidden @internal
-     */
-    @ViewChildren(IgxTemplateOutletDirective, { read: IgxTemplateOutletDirective })
-    public tmpOutlets: QueryList<any> = new QueryList<any>();
-
     /**
      * @hidden
      * @internal
@@ -4340,9 +4334,6 @@ export abstract class IgxGridBaseDirective implements GridType,
      * @hidden @internal
      */
     public ngOnDestroy() {
-        this.tmpOutlets.forEach((tmplOutlet) => {
-            tmplOutlet.cleanCache();
-        });
         this._autoGeneratedColsRefs.forEach(ref => ref.destroy());
         this._autoGeneratedColsRefs = [];
 

projects/igniteui-angular/src/lib/grids/grid/grid.component.ts

@@ -1,7 +1,7 @@
 import {
     Component, ChangeDetectionStrategy, Input, Output, EventEmitter, ContentChild, ViewChildren,
     QueryList, ViewChild, TemplateRef, DoCheck, AfterContentInit, HostBinding,
-    OnInit, AfterViewInit, ContentChildren, CUSTOM_ELEMENTS_SCHEMA, booleanAttribute
+    OnInit, AfterViewInit, ContentChildren, CUSTOM_ELEMENTS_SCHEMA, booleanAttribute, OnDestroy,
 } from '@angular/core';
 import { NgTemplateOutlet, NgClass, NgStyle } from '@angular/common';
 
@@ -159,7 +159,7 @@ export interface IGroupingDoneEventArgs extends IBaseEventArgs {
     ],
     schemas: [CUSTOM_ELEMENTS_SCHEMA]
 })
-export class IgxGridComponent extends IgxGridBaseDirective implements GridType, OnInit, DoCheck, AfterContentInit, AfterViewInit {
+export class IgxGridComponent extends IgxGridBaseDirective implements GridType, OnInit, DoCheck, AfterContentInit, AfterViewInit, OnDestroy {
     /**
      * Emitted when a new chunk of data is loaded from virtualization.
      *
@@ -1083,6 +1083,18 @@ export class IgxGridComponent extends IgxGridBaseDirective implements GridType,
         super.ngDoCheck();
     }
 
+    /**
+     * @hidden @internal
+     */
+    public override ngOnDestroy() {
+        super.ngOnDestroy();
+        for (const childTemplate of this.childDetailTemplates.values()) {
+            if (!childTemplate.view.destroyed) {
+                childTemplate.view.destroy();
+            }
+        }
+    }
+
     /**
      * @hidden @internal
      */

projects/igniteui-angular/src/lib/grids/hierarchical-grid/hierarchical-grid.component.ts

@@ -912,6 +912,12 @@ export class IgxHierarchicalGridComponent extends IgxHierarchicalGridBaseDirecti
 
     /** @hidden @internal **/
     public override ngOnDestroy() {
+        for (const childTemplate of this.childGridTemplates.values()) {
+            if (!childTemplate.view.destroyed) {
+                childTemplate.view.destroy();
+            }
+        }
+
         if (!this.parent) {
             this.gridAPI.getChildGrids(true).forEach((grid) => {
                 if (!grid.childRow.cdr.destroyed) {
@@ -973,6 +979,10 @@ export class IgxHierarchicalGridComponent extends IgxHierarchicalGridBaseDirecti
                 const tmlpOutlet = cachedData.owner;
                 return {
                     $implicit: rowData,
+                    templateID: {
+                        type: 'childRow',
+                        id: rowData.rowID
+                    },
                     moveView: view,
                     owner: tmlpOutlet,
                     index: this.dataView.indexOf(rowData)

projects/igniteui-angular/src/lib/grids/hierarchical-grid/row-island.component.ts

@@ -582,7 +582,9 @@ export class IgxRowIslandComponent extends IgxHierarchicalGridBaseDirective
 
     private cleanGridState(grid) {
         grid.childGridTemplates.forEach((tmpl) => {
-            tmpl.owner.cleanView(tmpl.context.templateID);
+            if (!tmpl.view.destroyed) {
+                tmpl.view.destroy();
+            }
         });
         grid.childGridTemplates.clear();
         grid.onRowIslandChange();