Roku SceneGraph - check URL for 404

Question

I'm new to Roku coding and I was wondering if there is a simple Function (non-Task Node) that I can use to check and see if a URL is valid or not and then just return a Yay or Nay so I can check a second URL? Thank you

Answer 1

You can find what you are looking for here: roSystemLog

You also have a good sample code in this link that you can follow.

Answer 2

You could try running Eval() on the url call, and check for a 400-level error. If the error is present then proceed to another Eval() call on the next url you want, and so on until you get a URL you can break out of the function with. Eval() will test the code, and if no errors will proceed, but if it throws a runtime error it will just stop THAT code execution and not crash the application. It's a pretty decent ad-hoc exception handler. See here: https://sdkdocs.roku.com/display/sdkdoc/Runtime+Functions#RuntimeFunctions-Eval(codeasString)asDynamic

Answer 3

You can make a request to the URL with an roTransfer, and check for errors. In this example, I'm using a GetHead(), since all you need to do is check for validity.

' given a 404 URL
url = "http://example.com/404"

' request HEAD for the URL
urlTransfer = CreateObject("roUrlTransfer")
urlTransfer.setUrl(url)
urlEvent = urlTransfer.head()
if urlEvent <> Invalid
    responseCode = urlEvent.getResponseCode()
    if responseCode >= 200 and responseCode < 300
        print "success"
    else
        print "fail with code " + Stri(responseCode)
    end if
else
    print "transfer failed"
end if