Check if many things are valid in BrightScript

When programming BrightScript, there will certainly come a time when you will need to check if multiple variables are valid; or if you’re not using my isValid() helper function, if multiple variables are not invalid.

In Roku’s documentation and sample code you may see this check written as:

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if variable1 <> invalid and variable2 <> invalid and variable3 <> invalid
    doSomething()
end if

This works, but we can do better.

What if we use the isValid() function?

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if isValid(variable1) and isValid(variable2) and isValid(variable3)
    doSomething()
end if

That’s an improvement, but it’s still very verbose. That’s why I wrote a helper function to check multiple variables at once.

Simply pass it an array of items, and it will return a bool value indicating whether or not all the variables are valid.

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function isAllValid(input as object) as boolean
    for each item in input
        if not isValid(item) then return false
    end for
    return true
end function

You’ll notice the function returns as early as possible to save any unnecessary iterations.

This helper method keeps the code short, concise, and clean.

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if isAllValid([variable1, variable2, variable3])
    doSomething()
end if