test build

local/go-ucs/api/xml.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"encoding/xml"
+	"regexp"
+)
+
+// xmlMarshalWithSelfClosingTags post-processes results from xml.Marshal into XML
+// document where empty XML elements use self-closing tags.
+//
+// The XML standard states that self-closing tags are permitted.
+//
+// https://www.w3.org/TR/REC-xml/#dt-empty
+// https://www.w3.org/TR/REC-xml/#d0e2480
+//
+// According to the XML standard an empty element with a start and end tag is
+// semantically the same as an empty element with a self-closing tag.
+//
+// Unfortunately not all XML parsers can understand both. Such is the
+// case with Cisco UCS Manager API, which expects empty elements to use
+// self-closing tags only.
+//
+// As of now XML marshaling in Go always uses start and end tags,
+// which results in XML elements like the one below.
+//
+//    <Person name="me"></Person>
+//
+// Above XML elements cannot be parsed by the remote Cisco UCS API endpoint,
+// and such API calls result in parse error returned to the client.
+//
+// Currently the Go team is considering implementing XML self-closing tags,
+// which progress can be tracked in the issue below.
+//
+// https://github.com/golang/go/issues/21399
+//
+// Until support for XML self-closing tags (if ever) becomes real in Go
+// we need to ensure compatibility with the Cisco UCS API by doing that ourselves.
+//
+// In a separate thread @rsc also suggested a similar approach by using
+// strings.Replace(), even though such thing is not ideal and should
+// hopefully one day make into the language as a feature.
+//
+// https://groups.google.com/forum/#!topic/golang-nuts/guG6iOCRu08
+func xmlMarshalWithSelfClosingTags(in interface{}) ([]byte, error) {
+	data, err := xml.Marshal(in)
+	if err != nil {
+		return nil, err
+	}
+
+	re := regexp.MustCompile(`<([^/][\w\s\"\=\-\/]*)>\s*<(\/\w*)>`)
+	newData := re.ReplaceAllString(string(data), "<$1/>")
+
+	return []byte(newData), nil
+}