rules - Chirp

validation.rules

module

Built-in validation rules for chirp forms.

Each validator is a callable with the signature::

def rule(value: str) -> str | None:
    '''Return error message, or None if valid.'''

Parameterized validators are factory…

Built-in validation rules for chirp forms.

Each validator is a callable with the signature::

def rule(value: str) -> str | None:
    '''Return error message, or None if valid.'''

Parameterized validators are factory functions that return a validator::

def max_length(n: int) -> Callable[[str], str | None]:
    def check(value: str) -> str | None:
        if len(value) > n:
            return f"Must be at most {n} characters"
        return None
    return check

Custom validators follow the same protocol — any callable matching (str) -> str | None works with validate().

validation.rules

Name	Type	Default	Description
`type`		—
`qualified_name`		—
`element_type`		—
`description`		—
`source_file`		—
`line_number`		—
`is_autodoc`		—
`autodoc_element`		—
`_autodoc_template`		—
`_autodoc_url_path`		—
`_autodoc_page_type`		—
`title`		—
`doc_content_hash`		—

Symbols on this page

function required

Field must be present and non-empty.

function max_length

String must be at most n characters.

function min_length

String must be at least n characters.

function email

Value must be a valid email address (basic format check).

function url

Value must be a valid URL (http/https).

function matches

Value must match the given regex pattern.

function one_of

Value must be one of the given choices.

function integer

Value must be a valid integer.

function number

Value must be a valid number (int or float).

required

function

def required(value: str) -> str | None

Field must be present and non-empty.

Parameters

Name	Type	Default	Description
`value`	`str`	—

max_length

function

def max_length(n: int) -> Validator

String must be at most n characters.

Parameters

Name	Type	Default	Description
`n`	`int`	—

min_length

function

def min_length(n: int) -> Validator

String must be at least n characters.

Parameters

Name	Type	Default	Description
`n`	`int`	—

function

def email(value: str) -> str | None

Value must be a valid email address (basic format check).

Parameters

Name	Type	Default	Description
`value`	`str`	—

url

function

def url(value: str) -> str | None

Value must be a valid URL (http/https).

Parameters

Name	Type	Default	Description
`value`	`str`	—

matches

function

def matches(pattern: str, message: str | None = None) -> Validator

Value must match the given regex pattern.

Parameters

Name	Type	Default	Description
`pattern`	`str`	—
`message`	`str \| None`	`None`

one_of

function

def one_of(*choices: str) -> Validator

Value must be one of the given choices.

Parameters

Name	Type	Default	Description
`*choices`	`str`	—

integer

function

def integer(value: str) -> str | None

Value must be a valid integer.

Parameters

Name	Type	Default	Description
`value`	`str`	—

number

function

def number(value: str) -> str | None

Value must be a valid number (int or float).

Parameters

Name	Type	Default	Description
`value`	`str`	—

View source · /home/runner/work/chirp/chirp/site/../src/chirp/validation/rules.py:1