a Go package to interact with arbitrary JSON

The (only) constructor for *Json is from a []byte, which is not always ideal. Using an io.Reader can provide a small speed-up and reduction of memory usage, particularly in the case that the underlying JSON is large.

(My use-case was unmarshaling from an http.Response.Body containing arbitrary JSON.)

This defers the actual parsing of the text value to the numeric type until you dereference it using the Int(), Int64() or Float64() receiver methods.

This has the benefit that large integers (>= 1e6) are not marshaled in floating point exponent notation, and that very large integers (>= 2^53) do not lose precision when marshaled because they were stored internally as float64s.

I started exploring interface with some tests to see if we can update part of JSON using GetPath() .. Set(), which it seems you cannot do. My use case is that I have some path (the word "branch" is used in the code), and I want to update this with some value.

I've added SetBranch which you'd use like this:

js, err := NewJson([]byte(`{}`))

js.SetBranch([]string{"foo", "bar"}, "baz")

s, _ := js.GetPath("foo", "bar").String()

// s = "baz"! yay

I was tempted to do the API as SetBranch(val interface{}, branch ...string) but the pay back of getting the ... seems outweighed by the confusion of swapping key and value (relative to the Set method).

I'd love to avoid having to call Array() to get the length of an array element. But what I really want to do is iterate over the array length, like:

js.Get("json_node_with_array").Length()

or

len(js.Get("json_node_with_array"))

Alternatively, I'd be happy with a range operation:

for i, arrayElement := range js.Get("json_node_with_array") {
  arrayElement == js.Get("json_node_with_array").GetIndex(i)
}

Which one of those approaches seems right to you?

I think life will be a lot easier if Map/MustMap/Array/MustArray would return *Json instead of interface{}. No type assertion or casting would not be needed. Currently, it's like this:

func (j *Json) Map() (map[string]interface{}, error)
func (j *Json) MustMap(args ...map[string]interface{}) map[string]interface{}
func (j *Json) Array() ([]interface{}, error)
func (j *Json) MustArray(args ...[]interface{}) []interface{}

What I'm hoping is:

func (j *Json) Map() (map[string]*Json, error)
func (j *Json) MustMap(args ...map[string]interface{}) map[string]*Json
func (j *Json) Array() ([]*Json, error)
func (j *Json) MustArray(args ...[]interface{}) []*Json

Best regards, Elgs

Implements interfaces for go-simplejson to play nicely with the standard library's "encoding/json" package. Allows *Json types as struct fields, map values, and slice elements to be marshaled (and unmarshaled).

Also updates README.md which was missing the Bool() method

i have json like [{"a":1},{"b":2}] want to append {"c":3} to json array result is [{"a":1},{"b":2},{"c":3}] how? thank you very much

i have string teststring := {"fields_desc": {"cpUin": "44444" }} js,_ := simplejson.NewJson([]byte(teststring))

my question is how can i convert js to string? i use js.string(), but i get "".

I've created a Virtualbox-backed Vagrant box (hashicorp/precise64 image with 2 CPUs and 2048Mb of memory), installed git (using apt) and go 1.3.3 to the current directory from official tarball (https://storage.googleapis.com/golang/go1.3.3.linux-amd64.tar.gz) and try to build the google_auth_proxy:

vagrant@precise64:~$ GOROOT=go GOPATH=gopath go/bin/go get github.com/bitly/go-simplejson
go build github.com/bitly/go-simplejson: fork/exec go/pkg/tool/linux_amd64/6g: no such file or directory
vagrant@precise64:~$ ls -l go/pkg/tool/linux_amd64/6g
-rwxr-xr-x 1 vagrant vagrant 3461435 Oct  1 01:51 go/pkg/tool/linux_amd64/6g
vagrant@precise64:~$

At the same time I've tried doing the same on AWS and the build went fine.

(Not sure it in any way relates to the topic but I've run into that when I was trying to build google_auth_proxy, by the way thank you for the great tool)

I cannot get int value with MustInt after I set it. This example illustrate the problem:

func TestSetInt(t *testing.T) {
    js, _ := simplejson.NewJson([]byte(`{"x":1}`))
    t.Log("before", js.Get("x").MustInt())
    js.Set("x", 2)
    t.Log("after", js.Get("x").MustInt())
}

output:

before 1
after 0

Hi

I have json data like this: { "samekey": "value1", "samekey": "value2", "samekey": "value3" }

How to get the third one? I mean that which built-in function should I use.

Thanks in advance.

Hello.

is there any way to test the value for NULL?

Assume we have a json

{"someid":null}

And I want to test if the value is null, not just empty. For testing it as empty I can do something like require.Empty(simplejsonData.Get("someid"))

Any help is appreciated.

I want to iterate an array, and use the elements of the array as *simplejson.Json. I found no function to get size of array, the only way I found is to calculate len(jsonObj.Array), and I have no way to change jsonObj.MustArray()[i] to *simplejson.Json.

import (
        "fmt"
        sjson "github.com/bitly/go-simplejson"
)

func main() {
        body := `"{"client_id":"abc123","client_ip":"59.37.125.15","client_version":"1"}"`
        // body := `{"client_id":"abc123","client_ip":"59.37.125.15","client_version":"1"}`

        js, err := sjson.NewJson([]byte(body))
        if err != nil {
                fmt.Printf("failed to decode json(%s): %v", body, err) // should fail, but it does not!
                return
        }

        fmt.Printf("js: (%v)\n", js)
        return
}

When the encoded json field contains &, < or > symbols, they will be encoded in the form of ascii code. I know this is due to the json library and can be avoided by setEscapeHTML. Can you provide a similar function?

Hi, I had added ppc64le(Linux on Power) support on travis-ci in the branch and looks like its been successfully added. I believe it is ready for the final review and merge. The travis ci build logs can be verified from the link below.

https://travis-ci.com/github/ujjwalsh/go-simplejson/builds/188445179 Please have a look.

Regards, ujjwal