A working proxy exists.

packages/ipp/response.go

@@ -32,14 +32,16 @@ func (h *ippResponseHeader) unmarshal(byteStream io.Reader) {
 	binary.Read(byteStream, binary.BigEndian, &h.requestID)
 }
 
+// Response represens a ipp response object
 type Response struct {
-	a      *attributes
+	a      *Attributes
 	header ippResponseHeader
 }
 
+// NewResponse creates a new ipp response object
 func NewResponse(code statusCode, requestID uint32) *Response {
 	r := new(Response)
-	r.a = new(attributes)
+	r.a = new(Attributes)
 	r.header.versionNumber = 0x0101
 	r.header.requestID = requestID
 	r.header.statusCode = code
@@ -50,6 +52,7 @@ func (r Response) String() string {
 	return r.header.String() + "\n" + r.a.String()
 }
 
+// Marshal converts the response object to a wire formatted byte stream.
 func (r *Response) Marshal() []byte {
 	a := make([]byte, 0, 20)
 	a = append(a, r.header.marshal()...)
@@ -75,21 +78,63 @@ func (r *Response) Marshal() []byte {
 	return a
 }
 
+// UnMarshal unmarshals a ipp response into a response object
 func (r *Response) UnMarshal(body io.Reader) {
 	buffbody := bufio.NewReader(body)
 	r.header.unmarshal(buffbody)
-	//log.Printf("Header %v", r.header)
 	r.a = UnMarshalAttributes(buffbody)
 }
 
-func (r *Response) AddPrinterAttribute(a Attribute) {
-	r.a.addAttribute(printerAttributes, a)
+// AddPrinterAttribute adds a printer attribute to the response object
+func (r *Response) AddPrinterAttribute(a Attribute) error {
+	if a != nil {
+		r.a.addAttribute(printerAttributes, a)
+		return nil
+	}
+	return ErrNilAttribute
 }
 
-func (r *Response) AddOperatonAttribute(a Attribute) {
-	r.a.addAttribute(operationAttributes, a)
+// AddOperatonAttribute adds a printer attribute to the response object
+func (r *Response) AddOperatonAttribute(a Attribute) error {
+
+	if a != nil {
+		r.a.addAttribute(operationAttributes, a)
+		return nil
+	}
+	return ErrNilAttribute
 }
 
-func (r *Response) AddJobAttribute(a Attribute) {
-	r.a.addAttribute(jobAttributes, a)
+// AddJobAttribute adds a printer attribute to the response object
+func (r *Response) AddJobAttribute(a Attribute) error {
+	if a != nil {
+		r.a.addAttribute(jobAttributes, a)
+		return nil
+	}
+	return ErrNilAttribute
+}
+
+// GetAttribute retreives a attribute by name from the response object
+// returns nil a atribute with the provided name can be found.
+func (r *Response) GetAttribute(name string) Attribute {
+	for _, a := range r.a.operation {
+		if a.Name() == name {
+			return a
+		}
+	}
+	for _, a := range r.a.job {
+		if a.Name() == name {
+			return a
+		}
+	}
+	for _, a := range r.a.printer {
+		if a.Name() == name {
+			return a
+		}
+	}
+	for _, a := range r.a.unsupported {
+		if a.Name() == name {
+			return a
+		}
+	}
+	return nil
 }