Properties

type PropertyField = bool | int | float | str | Vector2 | list[bool] | list[int] | list[float] | list[str] | list[Vector2]

The value type of properties and attributes.

type PropertyFieldLike = bool | SupportsInt | SupportsFloat | str | Vector2Like | Sequence[bool] | Sequence[SupportsInt] | Sequence[SupportsFloat] | Sequence[str] | Sequence[Vector2Like]

Any value that is convertible to a PropertyField.

class Property

This class defines a property (similar to Python built-in properties), i.e., a pair of getter and setter. In addition, it holds (for auto- documentation) a default value, a description, and the name of the involved types. A property has a value of type PropertyField, which is one of bool, int, float, string, Vector2 or a collection (a vector in C++, a list in Python) thereof. Properties are used to configure sub-classes of HasProperties when using bindings like YAML or Python. Properties values are accessed using the methods exposed by HasProperties.

static make(property: object, default: PropertyFieldLike, type_name: str, description: str = '', schema: Callable | None = None, deprecated_names: Sequence[str] = []) → Property

Constructs a navground property from a Python property.

Parameters:

• property (property) – The Python property

• default (navground.core.PropertyField) – The default value (should be convertible to the property type)

• type_name (str) – The property type name

• description (str) – Optional description

• schema (collections.abc.Callable[[navground.core.schema.Schema], None]) – Optional schema modifier

• deprecated_names (list[str]) – A list of deprecated names for this property

static make_prototype(type_name: str) → PropertyField | None

Create a value of the desired type.

Parameters:

type_name – The type name

Returns:

A value or null is the type name is not valid.

property default_value

Type:

PropertyField

The property default value, i.e., the value of the property when the object is initialized.

property deprecated_names

Type:

list[str]

Alternative deprecated names for the property

property description

Type:

str

A textual description of the property, used for auto documentation.

property owner_type_name

Type:

str

The name of the property-owner type.

property readonly

Type:

bool

Whether the property is readonly

property type_name

Type:

str

The name of the property value type, used for auto documentation.

class HasProperties

This class defines set and get methods to access named Property “properties”.

get(name: str) → PropertyField

Gets the value of the specified property.

Parameters:

name – The name of the property

Raise:

RuntimeError A runtime error if no property is found.

Returns:

The value of the property

get_property_type_name(name: str) → str

Gets the type of a property.

Parameters:

name – The name of the property

Returns:

The property type name or an empty string if the property is not defined.

has(name: str) → bool

Checks whether a property exists.

Parameters:

name – The name of the property

Returns:

True if the property exists

set(name: str, value: PropertyFieldLike) → None

Set the value of a named property. Fails silently if no property can be found or if the value has a non-compatible type.

Parameters:

• name – The name of the property

• value – The desired value for the property