How to Remove a Specific Error with Angular's setErrors()

Taisei — Sat, 06 Sep 2025 12:56:02 +0000

Introduction

When building forms in Angular, have you ever faced this situation?

"I want to remove only a specific validation error,
but I want to keep the others."

The built-in setErrors() method in Angular makes this harder than expected.

A Common Scenario

Consider a product search form with a price range.
The user inputs minPrice and maxPrice.

The form requires these validations:

Both fields are required (required)
Values must be at least 0 (min)
minPrice <= maxPrice must hold

A Problematic Implementation

Validation rule #3 needs a custom validator.
Many developers try something like this:

// All errors are cleared
if (minPrice <= maxPrice) {
  control.setErrors(null);
}

What's Wrong?

Calling setErrors(null) clears all errors.

For example:

{ required: true, min: true, customError: true }

If you only wanted to remove customError,
required and min are also removed.
As a result, important error messages disappear.

Why Does This Happen?

It's because of how Angular's setErrors works:

setErrors(
  errors: ValidationErrors | null,
  opts: { emitEvent?: boolean } = {}
): void

Pass a ValidationErrors object -> replaces current errors
Pass null -> means "no errors"

Solution: Remove Only a Specific Error

The safe approach has three steps:

Get the current errors
Delete only the target error
Reset with remaining errors (or null if empty)

Example

const errors = control.errors || {};
delete errors.customError;
control.setErrors(
  Object.keys(errors).length ? errors : null
);
// Result: { required: true, min: true }

Conclusion

Using setErrors(null) blindly may clear needed errors

Key Points:

setErrors replaces all existing errors
To remove one error, keep others and reset

With this pattern, you can safely handle complex validations.

First Post on Dev.to!

Taisei — Sun, 31 Aug 2025 12:25:40 +0000

Introduction

Hello, I'm Taisei!
I work as a sofftware engineer in Japan.🇯🇵

There are two main reasons why I started writing on Dev.to:

I want to improve my technical skills in English.
I want to build a career overseas.

Motivation

I faced a problem in Angular Material that I couldn't solve.
So, I checked the issues on GitHub.
There, engineers were having active discussions in English.

At that moment, I felt strongly：”This is an unknown world.”

I have never been abroad and I don't have foreign friends.
That's why I want to combine programming, our common language, with English.
I want to jump into the place where engineers around the world debate on Github.

I don't want to rely only on translation tools.
I want to connect heart to heart as fellow engineers.
This feeling pushed me to take my first step.

Background and Skills

I started my career by coding websites and have been working as a frontend engineer for about 4 years. Currently, I'm involved in the development and operation of a membership-based online service for a major manufacturer.

The main technologies I use are:

TypeScript
Angular
Python

Conclusion

My English writing is still rough.
But I believe constant challenges will make me stronger.
I'd love to connect with people who also aim for growth.
Let's learn and improve together!

Forem: Taisei

How to Remove a Specific Error with Angular's setErrors()

Introduction

A Common Scenario

A Problematic Implementation

What's Wrong?

Why Does This Happen?

Solution: Remove Only a Specific Error

Example

Conclusion

First Post on Dev.to!

Introduction

Motivation

Background and Skills

Conclusion