Function reflectValue

query/encode.go:151–276

reflectValue populates the values parameter from the struct fields in val. Embedded structs are followed recursively (using the rules defined in the Values function documentation) breadth-first.

(values url.Values, val reflect.Value, scope string)

// Embedded structs are followed recursively (using the rules defined in the
// Values function documentation) breadth-first.
func reflectValue(values url.Values, val reflect.Value, scope string) error {
	var embedded []reflect.Value

	typ := val.Type()
	for i := 0; i < typ.NumField(); i++ {
		sf := typ.Field(i)
		if sf.PkgPath != "" && !sf.Anonymous { // unexported
			continue
		}

		sv := val.Field(i)
		tag := sf.Tag.Get("url")
		if tag == "-" {
			continue
		}
		name, opts := parseTag(tag)

		if name == "" {
			if sf.Anonymous {
				v := reflect.Indirect(sv)
				if v.IsValid() && v.Kind() == reflect.Struct {
					// save embedded struct for later processing
					embedded = append(embedded, v)
					continue
				}
			}

			name = sf.Name
		}

		if scope != "" {
			name = scope + "[" + name + "]"
		}

		if opts.Contains("omitempty") && isEmptyValue(sv) {
			continue
		}

		if sv.Type().Implements(encoderType) {
			// if sv is a nil pointer and the custom encoder is defined on a non-pointer
			// method receiver, set sv to the zero value of the underlying type
			if !reflect.Indirect(sv).IsValid() && sv.Type().Elem().Implements(encoderType) {
				sv = reflect.New(sv.Type().Elem())
			}

			m := sv.Interface().(Encoder)
			if err := m.EncodeValues(name, &values); err != nil {
				return err
			}
			continue
		}

		// recursively dereference pointers. break on nil pointers
		for sv.Kind() == reflect.Ptr {
			if sv.IsNil() {
				break
			}
			sv = sv.Elem()