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package simplejson
import (
"encoding/json"
"errors"
"log"
)
// returns the current implementation version
func Version() string {
return "0.5.0"
}
type Json struct {
data interface{}
}
// NewJson returns a pointer to a new `Json` object
// after unmarshaling `body` bytes
func NewJson(body []byte) (*Json, error) {
j := new(Json)
err := j.UnmarshalJSON(body)
if err != nil {
return nil, err
}
return j, nil
}
// New returns a pointer to a new, empty `Json` object
func New() *Json {
return &Json{
data: make(map[string]interface{}),
}
}
// Interface returns the underlying data
func (j *Json) Interface() interface{} {
return j.data
}
// Encode returns its marshaled data as `[]byte`
func (j *Json) Encode() ([]byte, error) {
return j.MarshalJSON()
}
// EncodePretty returns its marshaled data as `[]byte` with indentation
func (j *Json) EncodePretty() ([]byte, error) {
return json.MarshalIndent(&j.data, "", " ")
}
// Implements the json.Marshaler interface.
func (j *Json) MarshalJSON() ([]byte, error) {
return json.Marshal(&j.data)
}
// Set modifies `Json` map by `key` and `value`
// Useful for changing single key/value in a `Json` object easily.
func (j *Json) Set(key string, val interface{}) {
m, err := j.Map()
if err != nil {
return
}
m[key] = val
}
// SetPath modifies `Json`, recursively checking/creating map keys for the supplied path,
// and then finally writing in the value
func (j *Json) SetPath(branch []string, val interface{}) {
if len(branch) == 0 {
j.data = val
return
}
// in order to insert our branch, we need map[string]interface{}
if _, ok := (j.data).(map[string]interface{}); !ok {
// have to replace with something suitable
j.data = make(map[string]interface{})
}
curr := j.data.(map[string]interface{})
for i := 0; i < len(branch)-1; i++ {
b := branch[i]
// key exists?
if _, ok := curr[b]; !ok {
n := make(map[string]interface{})
curr[b] = n
curr = n
continue
}
// make sure the value is the right sort of thing
if _, ok := curr[b].(map[string]interface{}); !ok {
// have to replace with something suitable
n := make(map[string]interface{})
curr[b] = n
}
curr = curr[b].(map[string]interface{})
}
// add remaining k/v
curr[branch[len(branch)-1]] = val
}
// Del modifies `Json` map by deleting `key` if it is present.
func (j *Json) Del(key string) {
m, err := j.Map()
if err != nil {
return
}
delete(m, key)
}
// Get returns a pointer to a new `Json` object
// for `key` in its `map` representation
//
// useful for chaining operations (to traverse a nested JSON):
// js.Get("top_level").Get("dict").Get("value").Int()
func (j *Json) Get(key string) *Json {
m, err := j.Map()
if err == nil {
if val, ok := m[key]; ok {
return &Json{val}
}
}
return &Json{nil}
}
// GetPath searches for the item as specified by the branch
// without the need to deep dive using Get()'s.
//
// js.GetPath("top_level", "dict")
func (j *Json) GetPath(branch ...string) *Json {
jin := j
for _, p := range branch {
jin = jin.Get(p)
}
return jin
}
// GetIndex returns a pointer to a new `Json` object
// for `index` in its `array` representation
//
// this is the analog to Get when accessing elements of
// a json array instead of a json object:
// js.Get("top_level").Get("array").GetIndex(1).Get("key").Int()
func (j *Json) GetIndex(index int) *Json {
a, err := j.Array()
if err == nil {
if len(a) > index {
return &Json{a[index]}
}
}
return &Json{nil}
}
// CheckGet returns a pointer to a new `Json` object and
// a `bool` identifying success or failure
//
// useful for chained operations when success is important:
// if data, ok := js.Get("top_level").CheckGet("inner"); ok {
// log.Println(data)
// }
func (j *Json) CheckGet(key string) (*Json, bool) {
m, err := j.Map()
if err == nil {
if val, ok := m[key]; ok {
return &Json{val}, true
}
}
return nil, false
}
// Map type asserts to `map`
func (j *Json) Map() (map[string]interface{}, error) {
if m, ok := (j.data).(map[string]interface{}); ok {
return m, nil
}
return nil, errors.New("type assertion to map[string]interface{} failed")
}
// Array type asserts to an `array`
func (j *Json) Array() ([]interface{}, error) {
if a, ok := (j.data).([]interface{}); ok {
return a, nil
}
return nil, errors.New("type assertion to []interface{} failed")
}
// Bool type asserts to `bool`
func (j *Json) Bool() (bool, error) {
if s, ok := (j.data).(bool); ok {
return s, nil
}
return false, errors.New("type assertion to bool failed")
}
// String type asserts to `string`
func (j *Json) String() (string, error) {
if s, ok := (j.data).(string); ok {
return s, nil
}
return "", errors.New("type assertion to string failed")
}
// Bytes type asserts to `[]byte`
func (j *Json) Bytes() ([]byte, error) {
if s, ok := (j.data).(string); ok {
return []byte(s), nil
}
return nil, errors.New("type assertion to []byte failed")
}
// StringArray type asserts to an `array` of `string`
func (j *Json) StringArray() ([]string, error) {
arr, err := j.Array()
if err != nil {
return nil, err
}
retArr := make([]string, 0, len(arr))
for _, a := range arr {
if a == nil {
retArr = append(retArr, "")
continue
}
s, ok := a.(string)
if !ok {
return nil, err
}
retArr = append(retArr, s)
}
return retArr, nil
}
// MustArray guarantees the return of a `[]interface{}` (with optional default)
//
// useful when you want to interate over array values in a succinct manner:
// for i, v := range js.Get("results").MustArray() {
// fmt.Println(i, v)
// }
func (j *Json) MustArray(args ...[]interface{}) []interface{} {
var def []interface{}
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustArray() received too many arguments %d", len(args))
}
a, err := j.Array()
if err == nil {
return a
}
return def
}
// MustMap guarantees the return of a `map[string]interface{}` (with optional default)
//
// useful when you want to interate over map values in a succinct manner:
// for k, v := range js.Get("dictionary").MustMap() {
// fmt.Println(k, v)
// }
func (j *Json) MustMap(args ...map[string]interface{}) map[string]interface{} {
var def map[string]interface{}
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustMap() received too many arguments %d", len(args))
}
a, err := j.Map()
if err == nil {
return a
}
return def
}
// MustString guarantees the return of a `string` (with optional default)
//
// useful when you explicitly want a `string` in a single value return context:
// myFunc(js.Get("param1").MustString(), js.Get("optional_param").MustString("my_default"))
func (j *Json) MustString(args ...string) string {
var def string
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustString() received too many arguments %d", len(args))
}
s, err := j.String()
if err == nil {
return s
}
return def
}
// MustStringArray guarantees the return of a `[]string` (with optional default)
//
// useful when you want to interate over array values in a succinct manner:
// for i, s := range js.Get("results").MustStringArray() {
// fmt.Println(i, s)
// }
func (j *Json) MustStringArray(args ...[]string) []string {
var def []string
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustStringArray() received too many arguments %d", len(args))
}
a, err := j.StringArray()
if err == nil {
return a
}
return def
}
// MustInt guarantees the return of an `int` (with optional default)
//
// useful when you explicitly want an `int` in a single value return context:
// myFunc(js.Get("param1").MustInt(), js.Get("optional_param").MustInt(5150))
func (j *Json) MustInt(args ...int) int {
var def int
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustInt() received too many arguments %d", len(args))
}
i, err := j.Int()
if err == nil {
return i
}
return def
}
// MustFloat64 guarantees the return of a `float64` (with optional default)
//
// useful when you explicitly want a `float64` in a single value return context:
// myFunc(js.Get("param1").MustFloat64(), js.Get("optional_param").MustFloat64(5.150))
func (j *Json) MustFloat64(args ...float64) float64 {
var def float64
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustFloat64() received too many arguments %d", len(args))
}
f, err := j.Float64()
if err == nil {
return f
}
return def
}
// MustBool guarantees the return of a `bool` (with optional default)
//
// useful when you explicitly want a `bool` in a single value return context:
// myFunc(js.Get("param1").MustBool(), js.Get("optional_param").MustBool(true))
func (j *Json) MustBool(args ...bool) bool {
var def bool
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustBool() received too many arguments %d", len(args))
}
b, err := j.Bool()
if err == nil {
return b
}
return def
}
// MustInt64 guarantees the return of an `int64` (with optional default)
//
// useful when you explicitly want an `int64` in a single value return context:
// myFunc(js.Get("param1").MustInt64(), js.Get("optional_param").MustInt64(5150))
func (j *Json) MustInt64(args ...int64) int64 {
var def int64
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustInt64() received too many arguments %d", len(args))
}
i, err := j.Int64()
if err == nil {
return i
}
return def
}
// MustUInt64 guarantees the return of an `uint64` (with optional default)
//
// useful when you explicitly want an `uint64` in a single value return context:
// myFunc(js.Get("param1").MustUint64(), js.Get("optional_param").MustUint64(5150))
func (j *Json) MustUint64(args ...uint64) uint64 {
var def uint64
switch len(args) {
case 0:
case 1:
def = args[0]
default:
log.Panicf("MustUint64() received too many arguments %d", len(args))
}
i, err := j.Uint64()
if err == nil {
return i
}
return def
}