Fix: Pivot Grid auto-detects date fields from timestamps and date strings

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

@@ -7382,17 +7382,81 @@ export abstract class IgxGridBaseDirective implements GridType,
      */
     public resolveDataTypes(rec) {
         if (typeof rec === 'number') {
+            // Check if number is a valid timestamp (milliseconds since epoch)
+            if (this.isValidTimestamp(rec)) {
+                return GridColumnDataType.Date;
+            }
             return GridColumnDataType.Number;
         } else if (typeof rec === 'boolean') {
             return GridColumnDataType.Boolean;
         } else if (typeof rec === 'object' && rec instanceof Date) {
             return GridColumnDataType.Date;
-        } else if (typeof rec === 'string' && (/\.(gif|jpe?g|tiff?|png|webp|bmp)$/i).test(rec)) {
-            return GridColumnDataType.Image;
+        } else if (typeof rec === 'string') {
+            if ((/\.(gif|jpe?g|tiff?|png|webp|bmp)$/i).test(rec)) {
+                return GridColumnDataType.Image;
+            }
+            // Check if string is a valid date string
+            if (this.isValidDateString(rec)) {
+                return GridColumnDataType.Date;
+            }
         }
         return GridColumnDataType.String;
     }
 
+    /**
+     * @hidden
+     * Checks if a number is a valid timestamp (milliseconds since epoch)
+     */
+    private isValidTimestamp(value: number): boolean {
+        // Timestamps should be positive integers
+        if (!Number.isInteger(value) || value <= 0) {
+            return false;
+        }
+        // Reasonable timestamp range: from 1970 to year 2100
+        // Min: 0 (Jan 1, 1970)
+        // Max: 4102444800000 (Jan 1, 2100)
+        const MIN_TIMESTAMP = 0;
+        const MAX_TIMESTAMP = 4102444800000;
+        if (value < MIN_TIMESTAMP || value > MAX_TIMESTAMP) {
+            return false;
+        }
+        // Check if it's in milliseconds range (13 digits) to avoid false positives with regular numbers
+        // Timestamps from year 2001 onwards have 13 digits: 1000000000000 = September 9, 2001
+        const MIN_TIMESTAMP_MILLISECONDS = 1000000000000;
+        if (value < MIN_TIMESTAMP_MILLISECONDS) {
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * @hidden
+     * Checks if a string represents a valid date
+     */
+    private isValidDateString(value: string): boolean {
+        // Empty strings are not dates
+        if (!value || value.trim().length === 0) {
+            return false;
+        }
+        // Try to parse the string as a date
+        const parsedDate = new Date(value);
+        // Check if the date is valid (not NaN) and the string looks like a date
+        if (isNaN(parsedDate.getTime())) {
+            return false;
+        }
+        // Additional check: ensure the string contains date-like patterns
+        // to avoid false positives with strings like "2020" which could be just a year or a number string
+        const datePatterns = [
+            /^\d{4}-\d{2}-\d{2}/, // ISO format: YYYY-MM-DD
+            /^\d{2}\/\d{2}\/\d{4}/, // US format: MM/DD/YYYY
+            /^\d{4}\/\d{2}\/\d{2}/, // Alternative: YYYY/MM/DD
+            /^\d{2}-\d{2}-\d{4}/, // Alternative: DD-MM-YYYY or MM-DD-YYYY
+            /^\d{1,2}\/\d{1,2}\/\d{2,4}/, // Flexible: M/D/YY or M/D/YYYY
+            /^\w{3}\s+\d{1,2},?\s+\d{4}/, // Text month: Jan 1, 2020 or Jan 1 2020
+        ];
+        return datePatterns.some(pattern => pattern.test(value.trim()));
+    }
+
     /**
      * @hidden
      */

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

@@ -2402,6 +2402,7 @@ export class IgxPivotGridComponent extends IgxGridBaseDirective implements OnIni
         const rowDimensions: IPivotDimension[] = [];
         const values: IPivotValue[] = [];
         let isFirstDate = true;
+
         fields.forEach((field) => {
             const dataType = this.resolveDataTypes(data[0][field]);
             switch (dataType) {
@@ -2445,6 +2446,7 @@ export class IgxPivotGridComponent extends IgxGridBaseDirective implements OnIni
                 }
             }
         });
+
         const config: IPivotConfiguration = {
             columns: columnDimensions,
             rows: rowDimensions,

projects/igniteui-angular/src/lib/grids/pivot-grid/pivot-grid.spec.ts

@@ -2083,6 +2083,149 @@ describe('IgxPivotGrid #pivotGrid', () => {
                 expect(pivotGrid.values.map(x => x.enabled)).toEqual([true, true]);
             });
 
+            it('should auto-generate pivot config and detect date fields from timestamp values', () => {
+                const pivotGrid = fixture.componentInstance.pivotGrid;
+                pivotGrid.pivotConfiguration = undefined;
+                pivotGrid.autoGenerateConfig = true;
+
+                // Test with timestamp (milliseconds since epoch)
+                const TEST_TIMESTAMP = 1577829600000; // 2020-01-01 00:00:00 UTC
+                pivotGrid.data = [{
+                    ProductCategory: 'Clothing', 
+                    UnitPrice: 12.81, 
+                    SellerName: 'Stanley',
+                    Country: 'Bulgaria', 
+                    Date: TEST_TIMESTAMP, 
+                    UnitsSold: 282
+                }];
+                fixture.detectChanges();
+
+                // Verify date field is detected and config is generated
+                expect(pivotGrid.allDimensions.length).toEqual(4);
+                expect(pivotGrid.pivotConfiguration.rows.map(x => x.memberName)).toEqual(['AllPeriods']);
+                expect(pivotGrid.pivotConfiguration.rows.map(x => x.enabled)).toEqual([true]);
+
+                // Verify the timestamp is still in its original format (not pre-parsed)
+                // IgxPivotDateDimension will handle parsing on-demand
+                expect(pivotGrid.data[0].Date).toBe(TEST_TIMESTAMP);
+
+                // values should be UnitPrice and UnitsSold (not Date)
+                expect(pivotGrid.values.length).toEqual(2);
+                expect(pivotGrid.values.map(x => x.member)).toEqual(['UnitPrice', 'UnitsSold']);
+            });
+
+            it('should auto-generate pivot config and detect date fields from ISO date strings', () => {
+                const pivotGrid = fixture.componentInstance.pivotGrid;
+                pivotGrid.pivotConfiguration = undefined;
+                pivotGrid.autoGenerateConfig = true;
+
+                // Test with ISO date string
+                const TEST_DATE_STRING = '2008-06-20';
+                pivotGrid.data = [{
+                    ProductCategory: 'Clothing', 
+                    UnitPrice: 12.81, 
+                    SellerName: 'Stanley',
+                    Country: 'Bulgaria', 
+                    Date: TEST_DATE_STRING, 
+                    UnitsSold: 282
+                }];
+                fixture.detectChanges();
+
+                // Verify date field is detected and config is generated
+                expect(pivotGrid.allDimensions.length).toEqual(4);
+                expect(pivotGrid.pivotConfiguration.rows.map(x => x.memberName)).toEqual(['AllPeriods']);
+                expect(pivotGrid.pivotConfiguration.rows.map(x => x.enabled)).toEqual([true]);
+
+                // Verify the date string is still in its original format (not pre-parsed)
+                // IgxPivotDateDimension will handle parsing on-demand
+                expect(pivotGrid.data[0].Date).toBe(TEST_DATE_STRING);
+            });
+
+            it('should auto-generate pivot config and detect date fields from US format date strings', () => {
+                const pivotGrid = fixture.componentInstance.pivotGrid;
+                pivotGrid.pivotConfiguration = undefined;
+                pivotGrid.autoGenerateConfig = true;
+
+                // Test with US format date string (MM/DD/YYYY)
+                const TEST_US_DATE_STRING = '10/24/2025';
+                pivotGrid.data = [{
+                    ProductCategory: 'Clothing', 
+                    UnitPrice: 12.81, 
+                    SellerName: 'Stanley',
+                    Country: 'Bulgaria', 
+                    Date: TEST_US_DATE_STRING, 
+                    UnitsSold: 282
+                }];
+                fixture.detectChanges();
+
+                // Verify date field is detected and config is generated
+                expect(pivotGrid.allDimensions.length).toEqual(4);
+                expect(pivotGrid.pivotConfiguration.rows.map(x => x.memberName)).toEqual(['AllPeriods']);
+                expect(pivotGrid.pivotConfiguration.rows.map(x => x.enabled)).toEqual([true]);
+
+                // Verify the date string is still in its original format (not pre-parsed)
+                // IgxPivotDateDimension will handle parsing on-demand
+                expect(pivotGrid.data[0].Date).toBe(TEST_US_DATE_STRING);
+            });
+
+            it('should handle multiple date fields and enable only the first one', () => {
+                const pivotGrid = fixture.componentInstance.pivotGrid;
+                pivotGrid.pivotConfiguration = undefined;
+                pivotGrid.autoGenerateConfig = true;
+
+                // Test with multiple date fields
+                const TEST_START_TIMESTAMP = 1577829600000; // 2020-01-01
+                const TEST_END_DATE_STRING = '2020-12-31';
+                pivotGrid.data = [{
+                    ProductCategory: 'Clothing', 
+                    StartDate: TEST_START_TIMESTAMP, // timestamp
+                    EndDate: TEST_END_DATE_STRING, // date string
+                    UnitPrice: 12.81, 
+                    UnitsSold: 282
+                }];
+                fixture.detectChanges();
+
+                // Verify both date fields are detected
+                const rowDimensions = pivotGrid.pivotConfiguration.rows;
+                expect(rowDimensions.length).toEqual(2);
+                expect(rowDimensions.map(x => x.memberName)).toEqual(['AllPeriods', 'AllPeriods']);
+
+                // Only the first date should be enabled by default
+                expect(rowDimensions[0].enabled).toBe(true);
+                expect(rowDimensions[1].enabled).toBe(false);
+
+                // Verify date values remain in their original format (not pre-parsed)
+                // IgxPivotDateDimension will handle parsing on-demand
+                expect(pivotGrid.data[0].StartDate).toBe(TEST_START_TIMESTAMP);
+                expect(pivotGrid.data[0].EndDate).toBe(TEST_END_DATE_STRING);
+            });
+
+            it('should not treat regular numbers as timestamps', () => {
+                const pivotGrid = fixture.componentInstance.pivotGrid;
+                pivotGrid.pivotConfiguration = undefined;
+                pivotGrid.autoGenerateConfig = true;
+
+                // Test with regular small numbers that should not be timestamps
+                pivotGrid.data = [{
+                    ProductCategory: 'Clothing', 
+                    Quantity: 100,  // Regular number, not a timestamp
+                    Year: 2020,     // Year number, not a timestamp
+                    UnitPrice: 12.81
+                }];
+                fixture.detectChanges();
+
+                // Verify no date fields were detected (all should be in values or columns)
+                expect(pivotGrid.pivotConfiguration.rows.length).toEqual(0);
+
+                // Numbers should be treated as values
+                expect(pivotGrid.values.length).toEqual(3);
+                expect(pivotGrid.values.map(x => x.member).sort()).toEqual(['Quantity', 'Year', 'UnitPrice'].sort());
+
+                // Verify values were not converted
+                expect(pivotGrid.data[0].Quantity).toBe(100);
+                expect(pivotGrid.data[0].Year).toBe(2020);
+            });
+
             it('should allow creating  IgxPivotDateDimension with no base dimension and setting it later.', () => {
                 const pivotGrid = fixture.componentInstance.pivotGrid;
                 const dateDimension = new IgxPivotDateDimension();