Unmarshalling of a nil value does not work inside the XML namespace. #1
Description
I get about such an XML response from the API:
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body>
<GetSomeXMLResponse xmlns="http://example.com">
<GetSomeXMLResponseResult>
<SomeContainersHere xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="">
<row SomeContainerID="111">
<Items>
<row xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ItemID="222">
<NonNilValue>5.700000000000000e-001</NonNilValue>
<NilValue xsi:nil="true" />
</row>
<row xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ItemID="333">
<NonNilValue>2.700000000000000e-001</NonNilValue>
<NilValue xsi:nil="true" />
</row>
</Items>
</row>
</SomeContainersHere>
</GetSomeXMLResponseResult>
</GetSomeXMLResponse>
</soap:Body>
</soap:Envelope>All this is parsed into something like this:
type Item struct {
ID int64 `xml:"ItemID,attr"`
NonNilValue float64 `xml:"NonNilValue"`
NilValue null.Float64 `xml:"NilValue"`
}However, parsing xsi:nil="true" does not work, because xsi (as I understand it) is a namespace http://www.w3.org/2001/XMLSchema-instance here.
This is evident if you add logging:
func (f *Float64) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
for _, attr := range start.Attr {
log.Printf("attr: %#v",attr) // TODO: remove
if isXsiNilAttr(attr) {
f.Float64, f.Valid = 0, false
return d.Skip()
}
}
f.Valid = true
return d.DecodeElement(&f.Float64, &start)
}attr: xml.Attr{Name:xml.Name{Space:"http://www.w3.org/2001/XMLSchema-instance", Local:"nil"}, Value:"true"}
To make it work, I had to do this hack:
func isXsiNilAttr(attr xml.Attr) bool {
return (attr.Name.Space == "xsi" || attr.Name.Space == "http://www.w3.org/2001/XMLSchema-instance") &&
attr.Name.Local == "nil" && attr.Value == "true"
}But I think it's worth doing better and it's worth taking into account in the tests.