Checking existence of function

Archived
1

I was testing my channel on an older Roku running Firmware 3.1 and got this error

Member function not found in BrightScript Component or interface. (runtime error &hf4) in …G56RN/pkg:/source/appMain.brs(98)
098: busydialog.EnableOverlay(true)

which leads to two questions.

  1. Is there a way to check if an function is available before calling it? For example in javascript you could do this
    if (busydialog.EnableOverlay) {
    busydialog.EnableOverlay(true)
    }

  2. according to the docs (http://sdkdocs.roku.com/display/sdkdoc/ifMessageDialog) the EnableOverlay is listed as available since version 2.7. So why does it fail on a 3.1 box?

2

The global function FindMemberFunction is described to return “Invalid” if the function does not exist, or otherwise a reference to the interface defining the function. I do not know from what version FindMemberFunction is available, though.

FindMemberFunction(object as Object, funName as String) As Interface
3

FindMemberFunction has been around for many years. To be exact, the old release notes in the SDK documentation says it was added in Roku OS version 6.1 - 12/04/2014.

Generally speaking, for any function that is documented in the current SDK BrightScript reference without any annotation regarding it only being added in a recent firmware version, you can take its availability for granted.