fix(#3332): Exception when exporting more than 8 nested levels

projects/igniteui-angular/src/lib/services/excel/excel-exporter-grid.spec.ts

@@ -19,6 +19,7 @@ import { configureTestSuite } from '../../test-utils/configure-suite';
 import { IgxTreeGridPrimaryForeignKeyComponent } from '../../test-utils/tree-grid-components.spec';
 import { IgxTreeGridModule, IgxTreeGridComponent } from '../../grids/tree-grid';
 import { IgxNumberFilteringOperand } from '../../data-operations/filtering-condition';
+import { wait } from '../../test-utils/ui-interactions.spec';
 
 describe('Excel Exporter', () => {
     configureTestSuite();
@@ -449,6 +450,27 @@ describe('Excel Exporter', () => {
             fix.detectChanges();
             await exportAndVerify(treeGrid, options, actualData.treeGridDataExpDepth(0));
         });
+
+        it('should throw an exception when nesting level is greater than 8.', async () => {
+            const nestedData = SampleTestData.employeePrimaryForeignKeyTreeData();
+            for (let i = 1; i < 9; i++) {
+                nestedData[i - 1].ID = i;
+                nestedData[i - 1].ParentID = i - 1;
+            }
+            nestedData.push({ ID: 9, ParentID: 8, Name: 'Test', JobTitle: '', Age: 49 });
+            treeGrid.data = nestedData;
+            fix.detectChanges();
+            await wait(16);
+
+            let error = '';
+            try {
+                exporter.export(treeGrid, options);
+                await wait();
+            } catch (ex) {
+                error = ex.message;
+            }
+            expect(error).toMatch('Can create an outline of up to eight levels!');
+        });
     });
 
     function getExportedData(grid, exportOptions: IgxExcelExporterOptions) {

projects/igniteui-angular/src/lib/services/excel/excel-exporter.ts

@@ -1,17 +1,10 @@
 import * as JSZip from 'jszip/dist/jszip';
 
-import { CommonModule } from '@angular/common';
-import { Directive, EventEmitter, Injectable, NgModule, Output } from '@angular/core';
-
+import { EventEmitter, Injectable, Output } from '@angular/core';
 import { ExcelElementsFactory } from './excel-elements-factory';
 import { ExcelFolderTypes } from './excel-enums';
 import { IgxExcelExporterOptions } from './excel-exporter-options';
-
-import {
-    IExcelFile,
-    IExcelFolder
-} from './excel-interfaces';
-
+import { IExcelFolder } from './excel-interfaces';
 import { IgxBaseExporter } from '../exporter-common/base-export-service';
 import { ExportUtilities } from '../exporter-common/export-utilities';
 import { WorksheetData } from './worksheet-data';
@@ -45,8 +38,6 @@ export interface IExcelExportEndedEventArgs {
 export class IgxExcelExporterService extends IgxBaseExporter {
 
     private static ZIP_OPTIONS = { compression: 'DEFLATE', type: 'base64' };
-    private static DATA_URL_PREFIX = 'data:application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;base64,';
-
     private _xlsx: JSZip;
 
     /**
@@ -75,6 +66,16 @@ export class IgxExcelExporterService extends IgxBaseExporter {
     }
 
     protected exportDataImplementation(data: any[], options: IgxExcelExporterOptions): void {
+        if (this._isTreeGrid) {
+            let maxLevel = 0;
+            data.forEach((r) => {
+                maxLevel = Math.max(maxLevel, r.originalRowData.level);
+            });
+            if (maxLevel > 7) {
+                throw Error('Can create an outline of up to eight levels!');
+            }
+        }
+
         const worksheetData = new WorksheetData(data, options, this._indexOfLastPinnedColumn, this._sort, this._isTreeGrid);
         this._xlsx = new JSZip();