angular / angular/components

bug(material/chip): Mdc Chip Grid empties all options when using Reactive Forms and focusing out

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#26,358 19 comments 16 reactions 0 assignees View on GitHub
area: material/chips P4
Dominant language
TypeScript
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Description

### Is this a regression?

- [X] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

14.2.6

### Description

Having Reactive forms attached to `mat-chip-grid` which accepts an array of object values, clears them on focus out.

### Reproduction

Steps to reproduce:
1. Create a formgroup with some formControl
2. Bind it to ` `
3. Add some new options (or the same works if the list is already populated) that are **arrays of objects**.
4. Focus out of the component

https://stackblitz.com/edit/angular-6g9jz1?file=src%2Fapp%2Fchips-input-example.ts,src%2Fapp%2Fchips-input-example.html

Upon further investigation, figured that the core problem is that on focus out, object values are transformed to strings hence why we don't see the name property. Nevertheless objects were not transformed in v 14.

![mat-grid-bug](https://user-images.githubusercontent.com/26407402/210384868-edfda991-132a-48dd-9a44-90aeaeebaebc.gif)

_Note:_ In the Docs Chip list works as expected because it is not bound to Reactive forms

### Expected Behavior

All options remain with previously defined object values

### Actual Behavior

All options are transformed to strings thus we have empty text options

### Environment

- Angular: 15.0.4
- CDK/Material: 15.0.3
- Browser(s): Chrome 108.0.5359.124
- Operating System: macOS Ventura 13.1

Contributor guide

Open the contributing guide

Research direction

Start with the linked StackBlitz reproduction, especially src/app/chips-input-example.ts and src/app/chips-input-example.html, and inspect how mat-chip-grid is bound to Reactive Forms with object arrays. Reproduce the focus-out behavior, then verify that the options retain their object values and visible text afterward.

Written by the indexing model from the issue text.

Assessment

Tech stack
angular, typescript
Domain
frontend
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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