Function Optional

Optional<Instance extends object>(
Class: Constructor<Instance>,
): ParameterDecorator
Parameter decorator that injects the instance associated with the given class, or undefined if the class is not registered in the container.

Throws an error if a circular dependency is detected. Use function injection with optionalBy if resolving circular dependencies is necessary.
Type Parameters
- Instance extends object
Parameters
- Class: Constructor<Instance>
Returns ParameterDecorator
- Defined in decorators/optional.ts:13
Optional<Value>(token: Token<Value>): ParameterDecorator
Parameter decorator that injects the value associated with the given token, or undefined if the token is not registered in the container.

Throws an error if a circular dependency is detected. Use function injection with optionalBy if resolving circular dependencies is necessary.
Type Parameters
- Value
Parameters
- token: Token<Value>
Returns ParameterDecorator
- Defined in decorators/optional.ts:22
Optional<Value>(tokens: TokenRef<Value>): ParameterDecorator
Parameter decorator that injects the value associated with the given token, or undefined if the token is not registered in the container.

Allows referencing a token declared later in the file by using the tokenRef helper function.

Throws an error if a circular dependency is detected. Use function injection with optionalBy if resolving circular dependencies is necessary.
Type Parameters
- Value
Parameters
- tokens: TokenRef<Value>
Returns ParameterDecorator
Example
```
class Wizard {
  constructor(@Optional(tokenRef(() => Wand)) readonly wand: Wand | undefined) {}
}
// Other code...
class Wand {}
```
- Defined in decorators/optional.ts:43

Function Optional

Type Parameters

Parameters

Returns ParameterDecorator

Type Parameters

Parameters

Returns ParameterDecorator

Type Parameters

Parameters

Returns ParameterDecorator

Example

Settings