google.appengine.api.validation.Preferred

A non-deprecated field when there's a deprecated one.

Inherits From: Normalized, Validator, expected_type

google.appengine.api.validation.Preferred(
    deprecated, validator, default=None
)

For use with Deprecated. Only works as a field on Validated.

Both fields will work for value access. It's an error to set both the deprecated and the corresponding preferred field.

deprecated The name of the corresponding deprecated field
validator The validator for the actual value of this field.
default The default value for this field.

Child Classes

class expected_type

Methods

CheckFieldInitialized

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CheckFieldInitialized(
    value, key, obj
)

Check for missing fields or conflicts between fields.

Default behavior performs a simple None-check, but this can be overridden. If the intent is to allow optional fields, then use the Optional validator instead.

Args
value Value to validate.
key Name of the field being validated.
obj The object to validate against.

Raises
ValidationError When there are missing or conflicting fields.

Get

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Get(
    value, key, obj
)

Returns the normalized value. Subclasses must override.

GetWarnings

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GetWarnings(
    value, key, obj
)

Return any warnings on this attribute.

Validates the value with an eye towards things that aren't fatal problems.

Args
value Value to validate.
key Name of the field being validated.
obj The object to validate against.

Returns
A list of tuples (context, warning) where

  • Context is the field (or dotted field path, if a sub-field)
  • Warning is the string warning text

ToValue

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ToValue(
    value
)

Convert value to a simplified collection or basic type.

Subclasses of Validator should override this method when the dumped representation of value is not a simple <type>(value) (e.g., a regex).

Args
value An object of the same type that was returned from Validate().

Returns
An instance of a builtin type (e.g., int, str, dict, etc). By default it returns value unmodified.

Validate

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Validate(
    value, key
)

Validate this field. Override to customize subclass behavior.

Args
value Value to validate.
key Name of the field being validated.

Returns
Value if value is valid, or a valid representation of value.

__call__

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__call__(
    value, key='???'
)

Main interface to validator is call mechanism.