validation

introduction

dframework provides a globally available validate() helper that evaluates incoming data against a set of pipe separated rules. the validator handles both standard data objects and incoming multipart file uploads.

basic usage

you pass the data you want to validate as the first argument and an object containing the rules as the second argument. to validate files, you must pass the entire req object instead of just req.body.

the fails() method returns true if any rule was violated.

1export default class AuthController {
2  async register(req) {
3    const validation = validate(req.body, {
4      username: 'required|string|min:3|max:20',
5      email:    'required|email',
6      password: 'required|string|min:8'
7    });
8 
9    if (validation.fails()) {
10      return status(422).json({ success: false, errors: validation.errors() });
11    }
12 
13    // proceed with registration
14  }
15}

working with errors

the validation result object provides several methods for interacting with the error messages:

• fails(): returns true if validation failed
• passes(): returns true if validation succeeded
• errors(): returns an object mapping field names to an array of error messages
• first(field): returns the first error message for a specific field
• all(): returns a flat array of all error messages across all fields

when returning an html response rather than json, you typically use the .withErrors() and .withInput() helpers.

1export default class SettingsController {
2  async update(req) {
3    const validation = validate(req.body, {
4      display_name: 'nullable|string|max:50'
5    });
6 
7    if (validation.fails()) {
8      return back().withErrors(validation.errors()).withInput(req.body);
9    }
10    
11    // ...
12  }
13}

custom messages

you can provide an object as the third argument to define custom error messages. the keys must use the field.rule dot notation.

1const messages = {
2  'email.required': 'we really need your email address',
3  'email.email': 'that does not look like a valid email',
4  'password.min': 'your password must be at least 8 characters long'
5};
6 
7const validation = validate(req.body, rules, messages);

available rules

the built in rules cover the most common validation scenarios:

file validation

to validate uploaded files, you must pass the entire req object to the validator instead of req.body. the framework reads the uploaded files from req.files automatically.

file sizes can be specified in bytes, or with shorthand suffixes (kb, mb, gb).

1export default class UserProfileController {
2  async updateProfileImage(req) {
3    const validation = validate(req, {
4      profileImage: 'file_required|file_size:8mb|file_max_count:1|file_mimes:jpg,png,jpeg'
5    });
6 
7    if (validation.fails()) {
8      return status(422).json({ success: false, errors: validation.errors() });
9    }
10    
11    // ...
12  }
13}

the available file validation rules are: