coarnotify.exceptions

Module for custom exceptions

Exceptions

NotifyException	Base class for all exceptions in the coarnotifypy library
ValidationError	Exception class for validation errors.

Module Contents

exception coarnotify.exceptions.NotifyException

Bases: Exception

Base class for all exceptions in the coarnotifypy library

exception coarnotify.exceptions.ValidationError(errors: dict = None)

Bases: NotifyException

Exception class for validation errors.

Parameters:

errors – a dictionary of errors to construct the exception around. See below for the details of its structure

This class is designed to be thrown and caught and to collect validation errors as it passed through the validation pipeline.

For example an object validator may do something like this:

def validate():
    ve = ValidationError()
    ve.add_error(prop_name, validate.REQUIRED_MESSAGE.format(x=pn))
    if ve.has_errors():
        raise ve
    return True

If this is called by a subclass which is also validating, then this may be used like this:

def validate():
    ve = ValidationError()
    try:
        super(ClassName, self).validate()
    except ValidationError as superve:
        ve = superve

    ve.add_error(prop_name, validate.REQUIRED_MESSAGE.format(x=pn))
    if ve.has_errors():
        raise ve
    return True

By the time the ValidationError is finally raised to the top, it will contain all the validation errors from the various levels of validation that have been performed.

The errors are stored as a multi-level dictionary with the keys at the top level being the fields in the data structure which have errors, and within the value for each key there are two possible keys:

• errors: a list of error messages for this field

• nested: a dictionary of further errors for nested fields

{
    "key1": {
        "errors": ["error1", "error2"],
        "nested: {
            "key2": {
                errors: ["error3"]
            }
        }
    }
}

add_error(key: str, value: str)

Record an error on the supplied key with the message value

Parameters:

• key – the key for which an error is to be recorded

• value – the error message

Returns:

add_nested_errors(key: str, subve: ValidationError)

Take an existing ValidationError and add it as a nested set of errors under the supplied key

Parameters:

• key – the key under which all the nested validation errors should go

• subve – the existing ValidationError object

Returns:

has_errors() → bool

Are there any errors registered

property errors: dict

The dictionary of errors