func()

in webdav/internal/xml/marshal.go [556:716]

• 122 lines of code
• 49 McCabe index (conditional complexity)

func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo, startTemplate *StartElement) error {
	if startTemplate != nil && startTemplate.Name.Local == "" {
		return fmt.Errorf("xml: EncodeElement of StartElement with missing name")
	}

	if !val.IsValid() {
		return nil
	}
	if finfo != nil && finfo.flags&fOmitEmpty != 0 && isEmptyValue(val) {
		return nil
	}

	// Drill into interfaces and pointers.
	// This can turn into an infinite loop given a cyclic chain,
	// but it matches the Go 1 behavior.
	for val.Kind() == reflect.Interface || val.Kind() == reflect.Ptr {
		if val.IsNil() {
			return nil
		}
		val = val.Elem()
	}

	kind := val.Kind()
	typ := val.Type()

	// Check for marshaler.
	if val.CanInterface() && typ.Implements(marshalerType) {
		return p.marshalInterface(val.Interface().(Marshaler), p.defaultStart(typ, finfo, startTemplate))
	}
	if val.CanAddr() {
		pv := val.Addr()
		if pv.CanInterface() && pv.Type().Implements(marshalerType) {
			return p.marshalInterface(pv.Interface().(Marshaler), p.defaultStart(pv.Type(), finfo, startTemplate))
		}
	}

	// Check for text marshaler.
	if val.CanInterface() && typ.Implements(textMarshalerType) {
		return p.marshalTextInterface(val.Interface().(encoding.TextMarshaler), p.defaultStart(typ, finfo, startTemplate))
	}
	if val.CanAddr() {
		pv := val.Addr()
		if pv.CanInterface() && pv.Type().Implements(textMarshalerType) {
			return p.marshalTextInterface(pv.Interface().(encoding.TextMarshaler), p.defaultStart(pv.Type(), finfo, startTemplate))
		}
	}

	// Slices and arrays iterate over the elements. They do not have an enclosing tag.
	if (kind == reflect.Slice || kind == reflect.Array) && typ.Elem().Kind() != reflect.Uint8 {
		for i, n := 0, val.Len(); i < n; i++ {
			if err := p.marshalValue(val.Index(i), finfo, startTemplate); err != nil {
				return err
			}
		}
		return nil
	}

	tinfo, err := getTypeInfo(typ)
	if err != nil {
		return err
	}

	// Create start element.
	// Precedence for the XML element name is:
	// 0. startTemplate
	// 1. XMLName field in underlying struct;
	// 2. field name/tag in the struct field; and
	// 3. type name
	var start StartElement

	// explicitNS records whether the element's name space has been
	// explicitly set (for example an XMLName field).
	explicitNS := false

	if startTemplate != nil {
		start.Name = startTemplate.Name
		explicitNS = true
		start.Attr = append(start.Attr, startTemplate.Attr...)
	} else if tinfo.xmlname != nil {
		xmlname := tinfo.xmlname
		if xmlname.name != "" {
			start.Name.Space, start.Name.Local = xmlname.xmlns, xmlname.name
		} else if v, ok := xmlname.value(val).Interface().(Name); ok && v.Local != "" {
			start.Name = v
		}
		explicitNS = true
	}
	if start.Name.Local == "" && finfo != nil {
		start.Name.Local = finfo.name
		if finfo.xmlns != "" {
			start.Name.Space = finfo.xmlns
			explicitNS = true
		}
	}
	if start.Name.Local == "" {
		name := typ.Name()
		if name == "" {
			return &UnsupportedTypeError{typ}
		}
		start.Name.Local = name
	}

	// defaultNS records the default name space as set by a xmlns="..."
	// attribute. We don't set p.defaultNS because we want to let
	// the attribute writing code (in p.defineNS) be solely responsible
	// for maintaining that.
	defaultNS := p.defaultNS

	// Attributes
	for i := range tinfo.fields {
		finfo := &tinfo.fields[i]
		if finfo.flags&fAttr == 0 {
			continue
		}
		attr, err := p.fieldAttr(finfo, val)
		if err != nil {
			return err
		}
		if attr.Name.Local == "" {
			continue
		}
		start.Attr = append(start.Attr, attr)
		if attr.Name.Space == "" && attr.Name.Local == "xmlns" {
			defaultNS = attr.Value
		}
	}
	if !explicitNS {
		// Historic behavior: elements use the default name space
		// they are contained in by default.
		start.Name.Space = defaultNS
	}
	// Historic behaviour: an element that's in a namespace sets
	// the default namespace for all elements contained within it.
	start.setDefaultNamespace()

	if err := p.writeStart(&start); err != nil {
		return err
	}

	if val.Kind() == reflect.Struct {
		err = p.marshalStruct(tinfo, val)
	} else {
		s, b, err1 := p.marshalSimple(typ, val)
		if err1 != nil {
			err = err1
		} else if b != nil {
			EscapeText(p, b)
		} else {
			p.EscapeString(s)
		}
	}
	if err != nil {
		return err
	}

	if err := p.writeEnd(start.Name); err != nil {
		return err
	}

	return p.cachedWriteError()
}