FormArray.setErrors() does not work as intended

I’m submitting a…


[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

Setting formArray.setErrors(); does not set an error.

Expected behavior

The formArray should populate the .errors property and update its valid state accordingly.

Minimal reproduction of the problem with instructions

Plnkr

What is the motivation / use case for changing the behavior?

I’m implementing a validation that requires certain fields of a FormArray to be unique. If they are not, an error should be displayed on the FormArray level. The documentation clearly states that FormArray inherits .setErrors() from AbstractControl.

Environment


Angular version: 4.3.6


Browser:
- [x] Chrome (desktop) version XX
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [ ] IE version XX
- [ ] Edge version XX
 
For Tooling issues:
- Node version: XX  
- Platform:  

Others:

Issue Analytics

State:
Created 6 years ago
Comments:7 (1 by maintainers)

Top GitHub Comments

3reactions

mrajcokcommented, Apr 14, 2018

Thanks @kara. I was calling setErrors() inside a (ngModelChange) event handler, and it was not working… until I waited a tick with setTimeout().

2reactions

karacommented, Nov 2, 2017

As the documentation implies,setErrors should indeed set the errors. The problem in your example is that you’re setting the errors in the constructor, before validation has a chance to run in your form control directives. Once that validation happens, your errors will be overwritten. You can see in the updated plunker that if setErrors runs later, the errors update as expected (http://plnkr.co/edit/j1HHJwky17x79d5T4Ln2?p=preview). If you need to set errors as soon as the form loads, you can normally achieve this by waiting a tick for the next change detection run.