NGX Forms Validator

Tiny, fast, and made for Angular Reactive Forms

Docs · NPM · GitHub

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Features

• Lightweight and dependency-free
• Focused on Reactive Forms for Angular
• Multilingual support (English, Spanish, Esperanto)
• Built-in custom validators
• Customizable error messages and styling
• Configurable behaviors like markFieldsAsDirty and maxLengthWarning

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Installation

Installing NGX Forms Validator is as simple as running a single command in your Angular project:

npm i ngx-forms-validator

Once installed, you're ready to import the library and start validating forms — no additional setup or dependencies required.

Angular Compatibility

Supports Angular 14 and above — fully compatible with the latest Angular versions.

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Get Started

1. Set default language

import { TranslateService } from 'ngx-forms-validator';

constructor(private translateService: TranslateService) {
  this.translateService.setTranslationLanguaje('en_US');
}

2. Add validation service into your form

import { FormValidatorService } from 'ngx-forms-validator';

constructor(public formValidatorService: FormValidatorService) {}

ngOnInit(): void {
  this.form = this.formBuilder.group({
    name: ['', Validators.required]
  });

  this.formValidatorService.validateForm(this.form);
}

3. HTML structure

<form [formGroup]="form">
  <div>
    <input id="name" name="name" formControlName="name" />
  </div>
</form>

4. Optional configuration

this.formValidatorService.validateForm(this.form, {
  markFieldsAsDirty: true,
  showMaxLengthWarning: true
});

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Custom Literals

Create your own i18n literals and override the defaults:

export const customLiterals = {
  required: 'This field is required',
  email: 'Please enter a valid email'
};

this.translateService.setCustomTranslations(customLiterals);

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Default Literals

Built-in support for:

• en_US (English)
• es_ES (Spanish)
• eo_EO (Esperanto)

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Custom Validators

Use custom ones included in the lib:

onlyNumber → key: number
hasWhiteSpaceLine → key: whiteSpaceLine
hasLeadingWhiteSpace → key: leadingWhiteSpaceLine
hasTrailingWhiteSpace → key: trailingWhiteSpaceLine
introducedValueExists → key: introducedValueNoExist
maxByte → key: maxLength

Or create your own easily:

export class CustomValidators {
  public static noSpecialChars(control: AbstractControl): ValidationErrors | null {
    return /[^a-zA-Z0-9]/.test(control.value) ? { noSpecialChars: true } : null;
  }
}

Then add its literal key to your custom translations.

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Styling Guide

To use the default styling, include the stylesheet in your angular.json:

"styles": [
  "node_modules/ngx-forms-validator/styles/styles.scss"
]

You can override the styles using .ok-field, .error-field, .warning-field, etc.

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Error Message Behavior

You can fine-tune how and when messages appear using:

• markFieldsAsDirty
• showMaxLengthWarning

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Contribute

Found a bug or want to contribute? Open an issue or PR!

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License

MIT apalacios.dev