#Validator Directives

These directives validate field values in route parameters, request bodies, or model definitions.

#@string

Validates string values with various constraints.

Parameters:

• min_len: Minimum length of the string
• max_len: Maximum length of the string
• exact_len: Exact length the string must have
• start_with: String must start with this prefix
• end_with: String must end with this suffix

post /api/register {
    @json
    body {
        @string(min_len=3, max_len=20)
        username: str,
        
        @string(min_len=8, start_with="A")
        password: str
    }
}

#@number

Validates numeric values against specified constraints.

Parameters:

• min: Minimum value
• max: Maximum value
• equal: Value must equal this number

post /api/product {
    @json
    body {
        @number(min=1, max=1000)
        price: float,
        
        @number(min=0)
        quantity: int
    }
}

#@in

Validates that a value is one of a set of allowed values.

post /api/order {
    @json
    body {
        @in(["small", "medium", "large"])
        size: str,
        
        @in([1, 2, 3, 4, 5])
        rating: int
    }
}

#@regex

Validates that a string matches a given regular expression pattern.

post /api/register {
    @json
    body {
        @regex(pattern=r"^[a-zA-Z0-9_]+$")
        username: str,
        
        @regex(pattern=r"^\d{3}-\d{2}-\d{4}$")
        ssn: str
    }
}

#@format

Validates that a string conforms to a specific format.

Supported formats:

• email: Email address
• url: URL
• uuid: UUID
• ipv4: IPv4 address
• ipv6: IPv6 address
• date: Date (YYYY-MM-DD)
• datetime: Datetime (ISO 8601)
• time: Time (HH:MM:SS)
• month: Month (YYYY-MM)
• week: Week (YYYY-Www)
• color: HTML color code
• uscc: Unified Social Credit Code

post /api/user {
    @json
    body {
        @format(type="email")
        email: str,
        
        @format(type="url")
        website: str,
        
        @format(type="date")
        birthdate: str
    }
}

#@array

Validates arrays against specified constraints.

Parameters:

• min_len: Minimum number of items
• max_len: Maximum number of items
• unique: Whether items must be unique

post /api/tags {
    @json
    body {
        @array(min_len=1, max_len=5, unique=true)
        tags: array
    }
}

#@date

Validates that a string is a valid date in the specified format and range.

Parameters:

• format: Date format string (default: "YYYY-MM-DD")
• min: Minimum date
• max: Maximum date

post /api/event {
    @json
    body {
        @date(format="YYYY-MM-DD", min="2023-01-01", max="2023-12-31")
        event_date: str
    }
}

#@not

Negates another validator, passing if the inner validator fails.

post /api/product {
    @json
    body {
        @not(@in(["admin", "system"]))
        role: str
    }
}

#@or

Combines multiple validators with logical OR, passing if any of the inner validators pass.

post /api/identifier {
    @json
    body {
        @or([
            @format(type="email"),
            @regex(pattern=r"^\d{10}$")
        ])
        identifier: str  // Can be either email or 10-digit number
    }
}