blob: 1c8fd459753f6f388b75f753ab6cf4ef46b4f4f1 [file] [log] [blame]
package json
import (
"reflect"
)
// Extension holds a set of additional rules to be used when unmarshaling
// strict JSON or JSON-like content.
type Extension struct {
funcs map[string]funcExt
consts map[string]interface{}
keyed map[string]func([]byte) (interface{}, error)
encode map[reflect.Type]func(v interface{}) ([]byte, error)
unquotedKeys bool
trailingCommas bool
}
type funcExt struct {
key string
args []string
}
// Extend changes the decoder behavior to consider the provided extension.
func (dec *Decoder) Extend(ext *Extension) { dec.d.ext = *ext }
// Extend changes the encoder behavior to consider the provided extension.
func (enc *Encoder) Extend(ext *Extension) { enc.ext = *ext }
// Extend includes in e the extensions defined in ext.
func (e *Extension) Extend(ext *Extension) {
for name, fext := range ext.funcs {
e.DecodeFunc(name, fext.key, fext.args...)
}
for name, value := range ext.consts {
e.DecodeConst(name, value)
}
for key, decode := range ext.keyed {
e.DecodeKeyed(key, decode)
}
for typ, encode := range ext.encode {
if e.encode == nil {
e.encode = make(map[reflect.Type]func(v interface{}) ([]byte, error))
}
e.encode[typ] = encode
}
}
// DecodeFunc defines a function call that may be observed inside JSON content.
// A function with the provided name will be unmarshaled as the document
// {key: {args[0]: ..., args[N]: ...}}.
func (e *Extension) DecodeFunc(name string, key string, args ...string) {
if e.funcs == nil {
e.funcs = make(map[string]funcExt)
}
e.funcs[name] = funcExt{key, args}
}
// DecodeConst defines a constant name that may be observed inside JSON content
// and will be decoded with the provided value.
func (e *Extension) DecodeConst(name string, value interface{}) {
if e.consts == nil {
e.consts = make(map[string]interface{})
}
e.consts[name] = value
}
// DecodeKeyed defines a key that when observed as the first element inside a
// JSON document triggers the decoding of that document via the provided
// decode function.
func (e *Extension) DecodeKeyed(key string, decode func(data []byte) (interface{}, error)) {
if e.keyed == nil {
e.keyed = make(map[string]func([]byte) (interface{}, error))
}
e.keyed[key] = decode
}
// DecodeUnquotedKeys defines whether to accept map keys that are unquoted strings.
func (e *Extension) DecodeUnquotedKeys(accept bool) {
e.unquotedKeys = accept
}
// DecodeTrailingCommas defines whether to accept trailing commas in maps and arrays.
func (e *Extension) DecodeTrailingCommas(accept bool) {
e.trailingCommas = accept
}
// EncodeType registers a function to encode values with the same type of the
// provided sample.
func (e *Extension) EncodeType(sample interface{}, encode func(v interface{}) ([]byte, error)) {
if e.encode == nil {
e.encode = make(map[reflect.Type]func(v interface{}) ([]byte, error))
}
e.encode[reflect.TypeOf(sample)] = encode
}