Create a XML Decoder from a string or byte array GO

Question

I have a xml decode function in my app and I use xml.NewDecoder(resp.Body) to decode my xml. the NewDecoder functions receives an io.Reader. But the problem is that in my response from the server I receive the first 230 bytes i need to ignore and the remaining bytes are the xml encoded in base64 that I want to decode. Here an example of the response body:

    --RandomCaracteres...
    Content-Type: application/xml; charset=UTF-8; name=response_xml

    <Response success="1"/>
    --RandomCaracteres...
    Content-Type: text/xml; name=report.xml
    Content-Transfer-Encoding: base64
    PE5leHBvc2VSZXBvcnQgdmVyc2lvbj0iMi4wIj4KPHNjYW5zPgo8c2NhbiBpZD0iNDYwMCIgbmFt......

I need to read only the PE5leHBvc2VSZXBv... data. With the following code I can read the xml:

    bodyBytes, _ := ioutil.ReadAll(resp.Body)
    defer resp.Body.Close()
    data, err := base64.StdEncoding.DecodeString(string(bodyBytes)[230:])
    fmt.Println(data)

but I can't call the xml.NewDecoder() function because data is not a io.Reader type. Is there any way to creade a Decode object from a string?

Answer 1

Yes there is:

r := strings.NewReader(dataStr)

And likewise for byte arrays:

r := bytes.NewReader(dataBytes)

Or, using bytes, you can skip the Reader and NewDecoder entirely and just use Unmarshal directly:

err := xml.Unmarshal(dataBytes, &myobj)

Or with a string, cast and use Unmarshal:

err := xml.Unmarshal([]byte(dataStr), &myobj)