Validation Rules Engine (VRE) for Angular

@validation-rules-engine/angular connects policy-driven validation to Angular template-driven forms. Policies keep rules reusable and testable, while directives, services, components, and display strategies integrate them with the view.

Installation

npm install @validation-rules-engine/core @validation-rules-engine/angular underscore

The core package, Angular framework packages, RxJS, and Underscore are peer dependencies.

Add the optional default stylesheet:

{
  "styles": [
    "node_modules/@validation-rules-engine/angular/styles/policy-validation.css"
  ]
}

The historic stylesheet filename, policyValidator directive API, policy-validation-* selectors, CSS classes, and DOM attributes remain stable compatibility contracts.

Features

• Reusable policy classes and fluent rules
• Nested model paths, conditional rules, and asynchronous validation
• Form-group and policy-group status tracking
• Field, group, policy-group, and model summaries
• Bootstrap, Angular Material, Tailwind-friendly, generic, automatic, and custom display strategies
• Dynamic policy replacement, refresh, evaluation, and cleanup APIs

Quick start

import { NgModule } from '@angular/core';
import {
  ValidationModule,
  ValidationPolicy,
  ValidationProviderService,
  Validator,
  ValidatorHelper
} from '@validation-rules-engine/angular';

class UserFormPolicy implements ValidationPolicy {
  addValidations(v: ValidatorHelper): Validator[] {
    return [
      v.validateFor('email')
        .isRequired('Email is required')
        .isEmail('Enter a valid email address')
    ];
  }
}

@NgModule({
  imports: [ValidationModule.forRoot({ preset: 'bootstrap' })]
})
export class AppModule {
  constructor(validation: ValidationProviderService) {
    validation.register('UserForm', new UserFormPolicy());
    validation.registerFormGroupPolicy('userForm', 'UserForm');
  }
}

<input
  [(ngModel)]="model.email"
  policyValidator
  [validateModel]="'user.email'"
  [actualModel]="model"
  [withPolicy]="'UserForm'"
  groupName="userForm"
/>

<policy-validation-group-status
  [model]="model"
  groupName="userForm"
></policy-validation-group-status>

Policy groups

validation.registerPolicyGroup('checkout', {
  policies: ['PersonalInfo', 'ShippingAddress', 'BillingAddress'],
  formGroups: ['personalInfo', 'shippingInfo', 'billingInfo']
});

Use replacePolicy(name, policy) for generated forms and clear stale state when their shape changes:

validation.replacePolicy(policyName, generatedPolicy);
validation.clearValidationState(model, [policyName]);

Common exports

• ValidationModule, ValidationProviderService, and ValidatorDirective
• ValidationPolicy, Validator, ValidatorHelper, and ValidationHelper
• summary and status components for models, groups, and policy groups
• Bootstrap, Material, Tailwind, generic, default, and custom display strategies
• display configuration, resolver, factory, provider, and token APIs
• Angular Policy execution plus re-exported framework-neutral contracts

Showcase

The repository includes a private Angular consumer with Bootstrap, Material, and Tailwind-style examples:

npm install
npm start

License

MIT - see LICENSE.