Golang StructType.Field方法代码示例

func enc_struct(val *reflect.StructValue, typ *reflect.StructType, buffer *bytes.Buffer) os.Error {
	buffer.WriteString("{")
	first := true
	for i := 0; i < typ.NumField(); i++ {
		f := typ.Field(i)
		if f.Tag == "" {
			continue
		}
		tags := strings.Split(f.Tag[3:len(f.Tag)-1], ",", -1)
		l := buffer.Len()
		if first {
			buffer.WriteString(fmt.Sprintf("\"%v\":", tags[1]))
		} else {
			buffer.WriteString(fmt.Sprintf(",\"%v\":", tags[1]))
		}
		written, err := enc(val.Field(i), f.Type, buffer, tags[2] == "req")
		if err != nil {
			return err
		}
		if !written {
			buffer.Truncate(l)
		} else {
			first = false
		}
	}
	buffer.WriteString("}")
	return nil
}

func compileStruct(t *reflect.StructType) map[string]reflect.StructField {
	m := make(map[string]reflect.StructField)
	for i := 0; i < t.NumField(); i++ {
		f := t.Field(i)
		if f.PkgPath != "" {
			// ignore if not exported
			continue
		}
		name := f.Name
		if f.Tag != "" {
			name = f.Tag
		}
		m[name] = f
	}
	return m
}

func dec_struct(val *reflect.StructValue, typ *reflect.StructType, json map[string]interface{}) os.Error {
	for i := 0; i < typ.NumField(); i++ {
		f := typ.Field(i)
		if f.Tag == "" {
			continue
		}
		tags := strings.Split(f.Tag[3:len(f.Tag)-1], ",", -1)
		j, ok := json[tags[1]]
		if !ok {
			if tags[2] == "req" {
				return os.NewError("Field " + f.Name + " is missing")
			}
			continue
		}
		err := dec(val.Field(i), f.Type, j)
		if err != nil {
			return err
		}
	}
	return nil
}

func attributes(m interface{}) (map[string]reflect.Type, reflect.Type) {
	var st *reflect.StructType
	var typ reflect.Type
	if _, ok := reflect.Typeof(m).(*reflect.PtrType); ok {
		typ = reflect.Typeof(m).(*reflect.PtrType).Elem()
	} else {
		typ = reflect.Typeof(m)
	}
	st = typ.(*reflect.StructType)

	//fmt.Println(st.NumField())

	ret := make(map[string]reflect.Type)

	for i := 0; i < st.NumField(); i++ {
		p := st.Field(i)
		//fmt.Println(p.Name)
		if !p.Anonymous {
			ret[p.Name] = p.Type
		}
	}

	return ret, typ
}

// Unmarshal a single XML element into val.
func (p *Parser) unmarshal(val reflect.Value, start *StartElement) os.Error {
	// Find start element if we need it.
	if start == nil {
		for {
			tok, err := p.Token()
			if err != nil {
				return err
			}
			if t, ok := tok.(StartElement); ok {
				start = &t
				break
			}
		}
	}

	if pv, ok := val.(*reflect.PtrValue); ok {
		if pv.Get() == 0 {
			zv := reflect.MakeZero(pv.Type().(*reflect.PtrType).Elem())
			pv.PointTo(zv)
			val = zv
		} else {
			val = pv.Elem()
		}
	}

	var (
		data        []byte
		saveData    reflect.Value
		comment     []byte
		saveComment reflect.Value
		sv          *reflect.StructValue
		styp        *reflect.StructType
	)
	switch v := val.(type) {
	default:
		return os.ErrorString("unknown type " + v.Type().String())

	case *reflect.BoolValue:
		v.Set(true)

	case *reflect.SliceValue:
		typ := v.Type().(*reflect.SliceType)
		if _, ok := typ.Elem().(*reflect.Uint8Type); ok {
			// []byte
			saveData = v
			break
		}

		// Slice of element values.
		// Grow slice.
		n := v.Len()
		if n >= v.Cap() {
			ncap := 2 * n
			if ncap < 4 {
				ncap = 4
			}
			new := reflect.MakeSlice(typ, n, ncap)
			reflect.ArrayCopy(new, v)
			v.Set(new)
		}
		v.SetLen(n + 1)

		// Recur to read element into slice.
		if err := p.unmarshal(v.Elem(n), start); err != nil {
			v.SetLen(n)
			return err
		}
		return nil

	case *reflect.StringValue,
		*reflect.IntValue, *reflect.UintValue, *reflect.UintptrValue,
		*reflect.Int8Value, *reflect.Int16Value, *reflect.Int32Value, *reflect.Int64Value,
		*reflect.Uint8Value, *reflect.Uint16Value, *reflect.Uint32Value, *reflect.Uint64Value,
		*reflect.FloatValue, *reflect.Float32Value, *reflect.Float64Value:
		saveData = v

	case *reflect.StructValue:
		if _, ok := v.Interface().(Name); ok {
			v.Set(reflect.NewValue(start.Name).(*reflect.StructValue))
			break
		}

		sv = v
		typ := sv.Type().(*reflect.StructType)
		styp = typ
		// Assign name.
		if f, ok := typ.FieldByName("XMLName"); ok {
			// Validate element name.
			if f.Tag != "" {
				tag := f.Tag
				ns := ""
				i := strings.LastIndex(tag, " ")
				if i >= 0 {
					ns, tag = tag[0:i], tag[i+1:]
				}
				if tag != start.Name.Local {
					return UnmarshalError("expected element type <" + tag + "> but have <" + start.Name.Local + ">")
				}
				if ns != "" && ns != start.Name.Space {
//.........这里部分代码省略.........