@moe1399/ngx-dynamic-forms-validation

Server-side form validation library compatible with @moe1399/ngx-dynamic-forms. Use the same form configuration and validation rules on both client and server.

Installation

npm install @moe1399/ngx-dynamic-forms-validation

Usage

import { validateForm, validatorRegistry } from '@moe1399/ngx-dynamic-forms-validation';

// Register custom validators (same implementation as Angular client)
validatorRegistry.register('australianPhoneNumber', (value) => {
  if (!value) return true;
  return /^(\+61|0)[2-478]\d{8}$/.test(value.replace(/\s/g, ''));
});

// Use the same form config as your Angular app
const formConfig = {
  id: 'contact-form',
  fields: [
    {
      name: 'email',
      label: 'Email',
      type: 'email',
      validations: [
        { type: 'required', message: 'Email is required' },
        { type: 'email', message: 'Invalid email format' }
      ]
    },
    {
      name: 'phone',
      label: 'Phone',
      type: 'text',
      validations: [
        {
          type: 'custom',
          customValidatorName: 'australianPhoneNumber',
          message: 'Invalid Australian phone number'
        }
      ]
    }
  ]
};

// Validate submitted form data
const formData = {
  email: '[email protected]',
  phone: '0412345678'
};

const result = validateForm(formConfig, formData);

if (!result.valid) {
  console.log('Validation errors:', result.errors);
  // [{ field: 'email', message: 'Email is required', rule: 'required' }]
}

API

validateForm(config, data)

Validates form data against a form configuration.

Parameters:

• config: FormConfig - The form configuration (same as @moe1399/ngx-dynamic-forms)
• data: Record<string, any> - The form data to validate

Returns: ValidationResult

interface ValidationResult {
  valid: boolean;
  errors: FieldValidationError[];
}

interface FieldValidationError {
  field: string;      // e.g., "email" or "contacts[0].phone"
  message: string;
  rule: string;       // Validation type that failed
}

validateFieldValue(fieldConfig, value, formData?)

Validates a single field value.

Parameters:

• fieldConfig: FormFieldConfig - The field configuration
• value: any - The value to validate
• formData?: Record<string, any> - Optional full form data for contextual validation

Returns: ValidationResult

validatorRegistry

Registry for custom validators.

// Register a single validator
validatorRegistry.register('validatorName', (value, params, fieldConfig, formData) => {
  return true; // or false
});

// Register multiple validators
validatorRegistry.registerAll({
  validator1: (value) => true,
  validator2: (value) => true,
});

// Check if validator exists
validatorRegistry.has('validatorName');

// List all registered validators
validatorRegistry.list();

// Remove a validator
validatorRegistry.unregister('validatorName');

// Clear all validators
validatorRegistry.clear();

Built-in Validators

| Type | Value | Behavior | |------|-------|----------| | required | - | Non-empty value | | email | - | Valid email format | | minLength | number | String length >= value | | maxLength | number | String length <= value | | min | number | Numeric value >= value | | max | number | Numeric value <= value | | pattern | regex | Matches regex pattern | | custom | - | Uses customValidatorName |

Express.js Example

import express from 'express';
import { validateForm, validatorRegistry } from '@moe1399/ngx-dynamic-forms-validation';

const app = express();
app.use(express.json());

// Register validators at startup
validatorRegistry.register('australianPhoneNumber', (value) => {
  if (!value) return true;
  return /^(\+61|0)[2-478]\d{8}$/.test(value.replace(/\s/g, ''));
});

// Form config (could be loaded from database)
const formConfig = { /* ... */ };

app.post('/api/submit', (req, res) => {
  const result = validateForm(formConfig, req.body);

  if (!result.valid) {
    return res.status(400).json({ errors: result.errors });
  }

  // Process valid form data
  res.json({ success: true });
});

License

MIT