angular / angular/components

bug(Tabs): ExpressionChangedAfterItHasBeenCheckedError when providing MatTabNavPanel to tabPanel input of mat-tab-nav-bar

Abierto
#28,379 4 comentarios 5 reacciones 0 asignados Ver en GitHub
area: material/tabs P4
Lenguaje dominante
TypeScript
Estrellas
25k
Forks
6.8k
Merge medio
1 d 8 h
PR fusionados (30 d)
91

Descripción

### 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

Angular Material pre-MDC

### Description

mat-tab-nav-bar requires a reference to it's MatTabNavPanel via the tabPanel input. Documentation says this is optional but code makes it required as reported in https://github.com/angular/components/issues/26270.

However, when the mat-tab-nav-bar is wrapped in some other component, e.g. an AppHeaderComponent, but the MatTabNavPanel is outside this component, we need to pass the reference to the MatTabNavPanel via Input into the wrapper component like AppHeaderComponent and then use it in the template. This is the only way I can think of, but it throws a ExpressionChangedAfterItHasBeenCheckedError (quite obvious for everyone who understand Angular's CD resolution algorithm really good, but hard to understand for everyone else), for example

> ERROR Error: NG0100: ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked. Previous value for 'attr.aria-labelledby': 'mat-tab-link-4'. Current value: 'mat-tab-link-2'. Expression location: TabNavBarBasicExample component.

### Reproduction

StackBlitz link: https://stackblitz.com/edit/udrwuw?file=src%2Fexample%2Ftab-nav-bar-basic-example.html
Steps to reproduce:
1. Open developer console in browser
2. Click around on the Nav Items
3. Observe error in developer console

### Expected Behavior

No error. I suggest simply making tabPanel optional like stated in Documentation, but of course would be nice to have a good solution to use mat-tab-nav-bar in a wrapper component

### Actual Behavior

ExpressionChangedAfterItHasBeenCheckedError

### Environment

- Angular: 16+
- CDK/Material: 16+ aka MDC
- Browser(s): any
- Operating System (e.g. Windows, macOS, Ubuntu): any

Guía de contribución

Abrir la guía de contribución

Línea de trabajo

Empieza con la reproducción de StackBlitz, especialmente con src/example/tab-nav-bar-basic-example.html y el componente TabNavBarBasicExample, y luego inspecciona cómo se pasa MatTabNavPanel a través del wrapper. Reproduce el error haciendo clic en los elementos de navegación y compara el comportamiento con la entrada opcional tabPanel documentada; se considera terminado cuando el error de consola ya no se produce.

Escrito por el modelo de indexación a partir del texto del issue.

Evaluación

Stack tecnológico
angular, typescript
Área
frontend
Tipo de issue
Error
Dificultad
4/5
Tiempo estimado
3-5 días
Estado de actividad
Estancado
Claridad
Bastante claro
Aptitud para principiantes
35/100

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