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    Method GetExistingSystemManaged

    GetExistingSystemManaged<T>()

    Return an existing instance of a system of type T in this World.

    Declaration
    public T GetExistingSystemManaged<T>() where T : ComponentSystemBase
    Returns
    Type Description
    T

    The existing instance of system type T in this World. If no such instance exists, the method returns null.

    Type Parameters
    Name Description
    T

    The system type

    Remarks

    Note: This system reference is not guaranteed to be safe to use. If the system or world is destroyed then the OnDestroy and cleanup functionality will have been called for this system.

    If possible, using GetExistingSystem(Type) is preferred, and instead of public member data, component data is recommended for system level data that needs to be shared between systems or externally to them. This defines a data protocol for the system which is separated from the system functionality.

    Private member data which is only used internally to the system is recommended.

    Keep in mind using a managed reference for systems

    • encourages coupling of data and functionality
    • couples data to the system type with no direct path to decouple
    • does not provide lifetime or thread safety guarantees for data access
    • does not provide lifetime or thread safety guarantees for system access through the returned managed reference

    GetExistingSystemManaged(Type)

    Return an existing instance of a system of type type in this World. Prefer the version that takes a SystemTypeIndex where possible to avoid unnecessary reflection.

    Declaration
    public ComponentSystemBase GetExistingSystemManaged(Type type)
    Parameters
    Type Name Description
    Type type

    The system type

    Returns
    Type Description
    ComponentSystemBase

    The existing instance of system type type in this World. If no such instance exists, the method returns null.

    Remarks

    Note: This system reference is not guaranteed to be safe to use. If the system or world is destroyed then the OnDestroy and cleanup functionality will have been called for this system.

    If possible, using GetExistingSystem(Type) is preferred, and instead of public member data, component data is recommended for system level data that needs to be shared between systems or externally to them. This defines a data protocol for the system which is separated from the system functionality.

    Private member data which is only used internally to the system is recommended.

    Keep in mind using a managed reference for systems

    • encourages coupling of data and functionality
    • couples data to the system type with no direct path to decouple
    • does not provide lifetime or thread safety guarantees for data access
    • does not provide lifetime or thread safety guarantees for system access through the returned managed reference

    GetExistingSystemManaged(SystemTypeIndex)

    Return an existing instance of a system of type type in this World. This avoids unnecessary reflection.

    Declaration
    public ComponentSystemBase GetExistingSystemManaged(SystemTypeIndex type)
    Parameters
    Type Name Description
    SystemTypeIndex type

    The system type

    Returns
    Type Description
    ComponentSystemBase

    The existing instance of system type type in this World. If no such instance exists, the method returns null.

    Remarks

    Note: This system reference is not guaranteed to be safe to use. If the system or world is destroyed then the OnDestroy and cleanup functionality will have been called for this system.

    If possible, using GetExistingSystem(Type) is preferred, and instead of public member data, component data is recommended for system level data that needs to be shared between systems or externally to them. This defines a data protocol for the system which is separated from the system functionality.

    Private member data which is only used internally to the system is recommended.

    Keep in mind using a managed reference for systems

    • encourages coupling of data and functionality
    • couples data to the system type with no direct path to decouple
    • does not provide lifetime or thread safety guarantees for data access
    • does not provide lifetime or thread safety guarantees for system access through the returned managed reference
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