angular / angular/components

bug(mat-form-field): mat-label incorrectly displayed at init (behavior possible)

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#26,833 1 comment 0 reactions 0 assignees View on GitHub
area: material/form-field P4
Dominant language
TypeScript
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Description

### Is this a regression?

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

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

_No response_

### Description

Sometimes, when the component mat-form-field is initied too fastly, when we use mat-icon with the attribute matPrefix or matSuffix, the mat-label is misplaced only at the init of the entire component.

A possible behavior can be to initialize the mat-form-field with setTimeout at 100ms or more after the component loaded on ngOnInit().
But, when using ReactiveFormsModule, an error (NG01050: formControlName must be used with a parent formGroup directive) can still be present but the forms works **normally.**

### Reproduction

Steps to reproduce:
1. Create a mat-form-field
2. Add a mat-label to this one
3. Add a trailling mat-icon with matPrefix or matSuffix

### Expected Behavior

The mat-icon and mat-label must be placed normally, means the icon must be before the mat-label for example.

### Actual Behavior

The label must be placed after the icon for matSuffix but only at init he is misplaced above or below the mat-icon. The mat-label works normally after he is focused.

### Environment

- Angular: Angular 15.0.0
- CDK/Material: 15.2.2
- Browser(s): Brave, Edge
- Operating System (e.g. Windows, macOS, Ubuntu): Windows

Contributor guide

Open the contributing guide

Research direction

Start by reproducing the initialization case with Angular Material mat-form-field, mat-label, mat-icon, and matPrefix or matSuffix, including the ReactiveFormsModule scenario described. Inspect the mat-form-field initialization and ngOnInit timing, then verify that the icon and label are positioned correctly on first render without the reported formControlName error.

Written by the indexing model from the issue text.

Assessment

Tech stack
angular, typescript
Domain
frontend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
32/100

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