[Hierarchical Grid] Advanced filtering does not open when first record for nested row layout doesn't have data

[MayaKirova]

Description

Hierarchical grid with Advanced filtering in the toolbar does not open when you click the Advanced Filtering button.

• igniteui-angular version: 19.2.8
• browser: N/A

Steps to reproduce

If you have the following structure for the HGrid:

• Singers Data (root grid data)
  • Albums array (first row island)
    • Songs array (nested row island)

Then if under the the first record in Singers data, the first item in Albums does not have a Songs array, the error is thrown.

1. Open https://stackblitz.com/edit/zlfrzzv2-gqsuslzq
2. Click the advanced filtering button on the root level of the grid.

For original repro for Elements you can refer to this sample: https://staging.infragistics.com/products/ignite-ui-web-components/web-components/components/grids/hierarchical-grid/advanced-filtering#web-components-hierarchical-grid-advanced-filtering-example

Result

Error is thrown:

ERROR TypeError: Cannot read properties of undefined (reading '0')
at 1623.a2d35d56.chunk.js:8:585747
at Array.reduce ()
at wl.reduce (1623.a2d35d56.chunk.js:2:554487)
at e.generateChildEntity (1623.a2d35d56.chunk.js:8:585686)
at 1623.a2d35d56.chunk.js:8:585321
at Array.reduce ()
at wl.reduce (1623.a2d35d56.chunk.js:2:554487)
at e.generateSchema (1623.a2d35d56.chunk.js:8:585292)
at get schema (1623.a2d35d56.chunk.js:8:576158)
at e.generateEntity (1623.a2d35d56.chunk.js:2:1578003)

And dialog does not open.

Expected result

Dialog opens with no error.

Attachments

Attach a sample if available, and screenshots, if applicable.

[damyanpetev]

Seems to be pointing to code added here https://github.com/IgniteUI/igniteui-angular/pull/15562/files#diff-a76e1e85097c389b7043f2de7b532cdc0ee7eeca571ed770f1e5562de6e67c2fR1256-R1257

Although seems to be a specific case to do with Elements?
Because the same sample is fine in Angular https://stackblitz.com/edit/zlfrzzv2
So possibly something to do with delayed init of components?

[MayaKirova]

Same happens in angular if the first record does not have a value for the matching row island key. Here's an angular sample that reproduces the issue: https://stackblitz.com/edit/zlfrzzv2-gqsuslzq