37.4.4 Missing Components

If a package relies on a component, such as another Octave package, that may not be present it may be useful to install a function which informs users what to do when a particular component is missing. The function must be written by the package maintainer and registered with Octave using missing_component_hook.

값 = missing_component_hook ()

옛_값 = missing_component_hook (새_값)

missing_component_hook (새_값, "local")

Query or set the internal variable that specifies the function to call when a component of Octave is missing.

This can be useful for packagers that may split the Octave installation into multiple sub-packages, for example, to provide a hint to users for how to install the missing components.

함수 안에서 "local" 선택지를 넣어 부르면, 함수와 함수가 부른 종속 절차의 변수가 지역적으로 바뀝니다. 함수가 종료되면 원래 변숫값이 되돌아옵니다.

The hook function is expected to be of the form

함수 (component)

Octave will call 함수 with the name of the function that requires the component and a string describing the missing component. The hook function should return an error message to be displayed.

같이 보기: missing_function_hook.