From de648617b305c2cad7823d7b853a87d382c5dfa9 Mon Sep 17 00:00:00 2001
From: Viktor Kombov <vkombov@infragistics.com>
Date: Fri, 16 Oct 2026 13:23:38 +0300
Subject: [PATCH] fix(grid): preselect custom conditions in Excel-style
 filtering

---
 CHANGELOG.md                                  |  2 +
 .../excel-style-custom-dialog.component.ts    |  5 ++
 .../grids/grid/src/grid-filtering-ui.spec.ts  | 52 +++++++++++++++++++
 3 files changed, 59 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7d5d1e15d3..3698e26c0cb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ All notable changes for each version of this project will be documented in this
 
 ### Bug Fixes
 
+- `IgxGridComponent`, `IgxTreeGridComponent`, `IgxHierarchicalGridComponent`
+    - Excel-style filtering now preselects custom conditions in the filter dialog when no filter value has been entered yet.
 - **Forms**
     - `igx-checkbox`, `igx-switch` and `igx-radio-group` no longer turn invalid while the bound Signal Forms field is untouched and pristine, e.g. right after `reset()` or when a cross-field rule makes a pristine field required. The invalid state now shows only once the field is touched or dirty, as with reactive and template-driven forms.
 - `IgxAccordionComponent`
diff --git a/projects/igniteui-angular/grids/core/src/filtering/excel-style/excel-style-custom-dialog.component.ts b/projects/igniteui-angular/grids/core/src/filtering/excel-style/excel-style-custom-dialog.component.ts
index f584936a458..48a0f0373bf 100644
--- a/projects/igniteui-angular/grids/core/src/filtering/excel-style/excel-style-custom-dialog.component.ts
+++ b/projects/igniteui-angular/grids/core/src/filtering/excel-style/excel-style-custom-dialog.component.ts
@@ -190,6 +190,11 @@ export class IgxExcelStyleCustomDialogComponent {
     }
 
     private createCondition(conditionName: string) {
+        const condition = this.column.filters?.condition(conditionName);
+        if (condition) {
+            return condition;
+        }
+
         switch (this.column.dataType) {
             case GridColumnDataType.Boolean:
                 return IgxBooleanFilteringOperand.instance().condition(conditionName);
diff --git a/projects/igniteui-angular/grids/grid/src/grid-filtering-ui.spec.ts b/projects/igniteui-angular/grids/grid/src/grid-filtering-ui.spec.ts
index cab28e30a07..0654b9a1793 100644
--- a/projects/igniteui-angular/grids/grid/src/grid-filtering-ui.spec.ts
+++ b/projects/igniteui-angular/grids/grid/src/grid-filtering-ui.spec.ts
@@ -5,6 +5,7 @@ import { NoopAnimationsModule } from '@angular/platform-browser/animations';
 import { IgxInputDirective, IgxInputGroupComponent } from 'igniteui-angular/input-group';
 import { INPUT_DEBOUNCE_TIME } from 'igniteui-angular/grids/core';
 import { IgxGridComponent } from './grid.component';
+import { IgxExcelStyleCustomDialogComponent } from '../../core/src/filtering/excel-style/excel-style-custom-dialog.component';
 import { UIInteractions, wait } from '../../../test-utils/ui-interactions.spec';
 import { IgxGridFilteringCellComponent } from 'igniteui-angular/grids/core';
 import { IgxGridHeaderComponent } from 'igniteui-angular/grids/core';
@@ -3796,6 +3797,57 @@ describe('IgxGrid - Filtering actions - Excel style filtering #grid', () => {
             expect(GridFunctions.getExcelFilteringDDInput(fix, 1).value).toEqual('Less Than');
         }));
 
+        it('Should preselect custom string condition when opening the custom filter dialog.', fakeAsync(() => {
+            GridFunctions.clickExcelFilterIconFromCode(fix, grid, 'AnotherField');
+
+            GridFunctions.clickExcelFilterCascadeButton(fix);
+            tick();
+            fix.detectChanges();
+
+            GridFunctions.clickOperatorFromCascadeMenu(fix, 0);
+            tick(100);
+
+            expect(GridFunctions.getExcelFilteringDDInput(fix, 0).value).toEqual('custom');
+            expect(GridFunctions.getExcelFilteringInput(fix, 0).value).toEqual('');
+        }));
+
+        it('Should preselect custom number condition when opening the custom filter dialog.', fakeAsync(() => {
+            grid.getColumnByName('Downloads').filters = fix.componentInstance.customFilter;
+            fix.detectChanges();
+
+            GridFunctions.clickExcelFilterIconFromCode(fix, grid, 'Downloads');
+
+            GridFunctions.clickExcelFilterCascadeButton(fix);
+            tick();
+            fix.detectChanges();
+
+            GridFunctions.clickOperatorFromCascadeMenu(fix, 0);
+            tick(100);
+
+            expect(GridFunctions.getExcelFilteringDDInput(fix, 0).value).toEqual('custom');
+            expect(GridFunctions.getExcelFilteringInput(fix, 0).value).toEqual('');
+        }));
+
+        it('Should use the default condition when it is not defined in the column filters.', fakeAsync(() => {
+            GridFunctions.clickExcelFilterIconFromCode(fix, grid, 'AnotherField');
+
+            GridFunctions.clickExcelFilterCascadeButton(fix);
+            tick();
+            fix.detectChanges();
+
+            GridFunctions.clickOperatorFromCascadeMenu(fix, 0);
+            tick(100);
+
+            const dialog = fix.debugElement.query(By.directive(IgxExcelStyleCustomDialogComponent))
+                .componentInstance as IgxExcelStyleCustomDialogComponent;
+            dialog.selectedOperator = 'contains';
+            dialog.onCustomDialogOpening();
+
+            const expression = dialog.expressionsList[0].expression;
+            expect(expression.condition).toBe(IgxStringFilteringOperand.instance().condition('contains'));
+            expect(expression.conditionName).toEqual('contains');
+        }));
+
         it('Should display friendly conditions\' names in custom filter dialog.', fakeAsync(() => {
             GridFunctions.clickExcelFilterIconFromCode(fix, grid, 'ProductName');