Advance Form Validator

advance-form-validator is a powerful and flexible library for validating form data in JavaScript. It allows you to define complex validation rules and provides detailed feedback for user input errors.

Installation

To install the package, you can use npm or yarn:

npm install advance-form-validator

Or,

yarn add advance-form-validator

Quick Usage

Here's a basic example of how to use advance-form-validator in a React component:

Step 1: Import and Set Up

Import the validateForm function from the package and use it to validate your form data against defined rules.

Validation Rules

The validateForm function supports the following validation rules:

Type Validation:

• type: 'string' - Ensures the field is a string.
• type: 'number' - Ensures the field is a phone number.
• type: 'email' - Ensures the field is a valid email address.
• type: 'file' - Ensures the field is a valid file with type and size constraints.

Required Field:

• required: true - Field must not be empty.

Length Constraints:

• minLength - Minimum number of characters for a string.

• maxLength - Maximum number of characters for a string. File Constraints (for file inputs):

• allowedTypes - Array of allowed MIME types.

• maxSize - Maximum allowed file size in bytes.

Custom Messages:

• messages - Custom error messages for each validation rule. For example, messages: { required: 'This field is required.' }.

Example

Here's an example of how to use validateForm with a form that includes email, phone, username, password, full name, profile picture, and cover image fields.

const formData = {
  email: '[email protected]',
  phone: '1234567890',
  username: 'validUser',
  password: 'securePassword',
  fullName: 'John Doe',
  profilePic: fileInput.files[0],
  coverImage: fileInput.files[1]
};

Example Rules

you can pass custom message if you wnat else you don't need to pass message section

const rules = {
  email: { 
    type: 'email', 
    required: true,
    messages: {
      required: 'Email is mandatory.',
      email: 'Please enter a valid email address.'
    }
  },
  phone: { 
    type: 'number', 
    required: true,
    messages: {
      required: 'Phone number is required.',
      number: 'Invalid phone number format.'
    }
  },
  username: { 
    type: 'string', 
    minLength: 3, 
    maxLength: 20, 
    required: true,
    messages: {
      minLength: 'Username must be at least 3 characters long.',
      maxLength: 'Username can be at most 20 characters long.'
    }
  },
  password: { 
    type: 'string', 
    minLength: 8, 
    required: true,
    messages: {
      minLength: 'Password must be at least 8 characters long.'
    }
  },
  fullName: { 
    type: 'string', 
    minLength: 2,
    messages: {
      minLength: 'Full name must be at least 2 characters long.'
    }
  },
  profilePic: { 
    file: true,
    allowedTypes: ['image/jpeg', 'image/png'],
    maxSize: 1000000, // 1 MB
    messages: {
      required: 'Profile picture is required.',
      type: 'Invalid file type. Only JPEG and PNG are allowed.',
      maxSize: 'File size exceeds 1 MB.'
    }
  },
  coverImage: { 
    file: true,
    allowedTypes: ['image/jpeg', 'image/png'],
    maxSize: 2000000, // 2 MB
    messages: {
      required: 'Cover image is required.',
      type: 'Invalid file type. Only JPEG and PNG are allowed.',
      maxSize: 'File size exceeds 2 MB.'
    }
  }
};

const result = await validateForm(formData, rules);
console.log(result.errors);

// Handle valid data (if needed)
console.log('Valid Data:', result.data);

Combined error

const combinedErrors = Object.values(errors).flat();

Displaying Errors

{combinedErrors.length > 0 && (
        <div className="error-container">
          <h3>Form Errors:</h3>
          <ul>
            {combinedErrors.map((error, index) => (
              <li key={index}>{error}</li>
            ))}
          </ul>
        </div>
      )}