Validation

Implementing server-side validation is very easy with Manifest.

You can use the built-in custom validators to ensure that the data you are receiving is correctly formatted.

Syntax

In your backend.yml, you can add a validation object that lists the properties and their validators:

entities:
  Dog:
    properties:
      - name
      - { name: age, type: number }
    validation:
      name: { minLength: 3 } # The name should have at least 3 characters.
      age: { min: 1, max: 30 } # Age should be a number between 1 and 30.

Tip

Type validation is natively implemented with property types. You do not need to set it.

Ex: sending a string value for a boolean property type will throw an error.

Inline syntax

If you want to keep it short you can simply pass the validation object to the property object:

entities:
  🧑🏽‍🦱 Author:
    properties:
      - name
      - { name: email, type: email, validation: { isNotEmpty: true } }
      - { name: bio, type: textarea, validation: { maxLength: 300 } }

Both syntaxes (block and inline) can be used simultaneously. In case of declaration conflict, the inline declaration will prevail.

Optional values validation

If you have some values that are optional but that need to be validated if present, you can add the isOptional validator. The value will be compared against validators only if not undefined or null. Example:

entities:
  Employee:
    properties:
      - name
      - {
          name: email,
          type: email,
          validation: { contains: '@company.com', isOptional: true }
        } #  If provided, the email should contain "@company.com"

Response

If the validation fails, the response will list the validation error(s) in its body:

// Create a new Employee
POST /api/dynamic/employees
Content-Type: application/json
{
    "name": "John Doe",
    "email": "john@manifest.build"
}

// Response.
[
    {
        "property": "email",
        "constraints": {
            "contains": "The value must contain @company.com"
        }
    }
]

Available validators

Validator	Type	Description
required	boolean	Indicates whether the property must not be empty.
isDefined	boolean	Checks if value is defined (!== undefined, !== null).
isOptional	boolean	Checks if given value is empty (=== null, === undefined) and ignores all validators.
equals	any	Checks if value equals ("===") comparison.
notEquals	any	Checks if value not equal ("!==") comparison.
isEmpty	boolean	Indicates whether the property can be empty.
isNotEmpty	boolean	Indicates whether the property must not be empty. Alias for required
isIn	array	Checks if value is in an array of allowed values.
isNotIn	array	Checks if value not in an array of disallowed values.
min	number	The minimum value or length allowed for the property.
max	number	The maximum value or length allowed for the property.
contains	string	Checks if string contains the seed.
notContains	string	Checks if string does not contain the seed.
isAlpha	boolean	Checks if the string contains only letters (a-zA-Z).
isAlphanumeric	boolean	Checks if the string contains only letters and numbers.
isAscii	boolean	Checks if the string contains ASCII chars only.
isEmail	boolean	Checks if the string is an email.
isJSON	boolean	Checks if the string is valid JSON.
minLength	number	Checks if the string's length is not less than given number.
maxLength	number	Checks if the string's length is not more than given number.
matches	string	Checks if string matches the pattern.
isMimeType	boolean	Checks if the string matches to a valid MIME type format.