difficulties using XML in Brightscript

Question

I am very inexperienced in both using Brightscript and working with XML content, but I am currently challenged with doing both to develop a roku app. At the moment, I need to figure out how to sort through some XML from an online document to get some necessary data. Any advice would be appreciated.

here's what the XML document looks like. (more items exist within MediaModel nodes, but I do not think I need them.)

<ArrayOfMediaModel xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/BlueBridgeIntegration.Models">
  <MediaModel>
    <Archive_ID>...</Archive_ID>
    <Archive_Title>...</Archive_Title>
    <Description>...</Description>
    <Image_Path>...</Image_Path>
    <MP3>...</MP3>
    <MP4>...</MP4>
    <RTMP_Path>...</RTMP_Path>
    <Series_ID>...</Series_ID>
    <Title>...</Title>
  </MediaModel>
  <MediaModel>...</MediaModel>
  <MediaModel>...</MediaModel>
  ...
  <MediaModel>...</MediaModel>
</ArrayOfMediaModel>

Although summarized, this is the extent of the document. The most important items of information I need to extract from the XML is title, description, image, and the mp4.

In its current state, the code I have does little more than parse the XML content, but this is what code I have so far.

sub CreateRecentMenu()
    screen = CreateObject("roGridScreen")
    port = CreateObject("roMessagePort")
    xml = CreateObject("roXMLElement")

    xml_str = GetXML("[url to the XML document]")
    xml.Parse(xml_str)

    ...

    return
end sub

Thus far, my attempts to obtain the information I need from the document has proven program-breaking. Again, any advice is very much appreciated. Thank you.

EDIT : I was able to determine that the xml_str string is coming up as invalid, for what reason I am not sure. This is the code I have for obtaining the XML code as a string.

Function GetXML(url as String) as string
    data = ""
    port = CreateObject("roMessagePort")
    link = CreateObject("roUrlTransfer")
    link.setPort(port)
    link.setUrl(url)
    link.SetCertificatesFile ("common:/certs/ca-bundle.crt")
    link.InitClientCertificates ()

    if(link.AsyncGetToString())
        finished = False
        while not finished
            msg = wait(0, port)
            if msg = invalid
                finished = True
                print "failure to connect"
                link.AsyncCancel()
            else
                if type(msg) = "roUrlEvent"
                    finished = True
                    if msg.GetInt() = 1
                        response = msg.GetResponseCode()
                        if response <> 200
                            print response
                        else
                            data = msg.GetString()
                        end if
                    end if
                else
                    return invalid
                end if
            end if
        end while
    end if
    return data
End Function

Thus far, this is the only way i've been able to make the connection work. Again, any help is appreciated.

Answer 1

确保xml_str变量不为空或无效，并且GetXML函数运行良好。