/gabs

For parsing, creating and editing unknown or dynamic JSON in golang

Primary LanguageGoMIT LicenseMIT

Gabs

Gabs is a small utility for dealing with dynamic or unknown JSON structures in golang. It's pretty much just a helpful wrapper around the golang json.Marshal/json.Unmarshal behaviour and map[string]interface{} objects. It does nothing spectacular except for being fabulous.

https://godoc.org/github.com/Jeffail/gabs

##How to install:

go get github.com/Jeffail/gabs

##How to use

###Parsing and searching JSON

...

import "github.com/Jeffail/gabs"

jsonParsed, err := gabs.ParseJSON([]byte(`{
	"outter":{
		"inner":{
			"value1":10,
			"value2":22
		},
		"alsoInner":{
			"value1":20
		}
	}
}`))

var value float64
var ok bool

value, ok = jsonParsed.Path("outter.inner.value1").Data().(float64)
// value == 10.0, ok == true

value, ok = jsonParsed.Search("outter", "inner", "value1").Data().(float64)
// value == 10.0, ok == true

value, ok = jsonParsed.Path("does.not.exist").Data().(float64)
// value == 0.0, ok == false

exists := jsonParsed.Exists("outter", "inner", "value1")
// exists == true

exists := jsonParsed.Exists("does", "not", "exist")
// exists == false

exists := jsonParsed.ExistsP("does.not.exist")
// exists == false

...

###Iterating objects

...

jsonParsed, _ := gabs.ParseJSON([]byte(`{"object":{ "first": 1, "second": 2, "third": 3 }}`))

// S is shorthand for Search
children, _ := jsonParsed.S("object").ChildrenMap()
for key, child := range children {
	fmt.Printf("key: %v, value: %v\n", key, child.Data().(string))
}

...

###Iterating arrays

...

jsonParsed, _ := gabs.ParseJSON([]byte(`{"array":[ "first", "second", "third" ]}`))

// S is shorthand for Search
children, _ := jsonParsed.S("array").Children()
for _, child := range children {
	fmt.Println(child.Data().(string))
}

...

Will print:

first
second
third

Children() will return all children of an array in order. This also works on objects, however, the children will be returned in a random order.

###Searching through arrays

If your JSON structure contains arrays you can still search the fields of the objects within the array, this returns a JSON array containing the results for each element.

...

jsonParsed, _ := gabs.ParseJSON([]byte(`{"array":[ {"value":1}, {"value":2}, {"value":3} ]}`))
fmt.Println(jsonParsed.Path("array.value").String())

...

Will print:

[1,2,3]

###Generating JSON

...

jsonObj := gabs.New()
// or gabs.Consume(jsonObject) to work on an existing map[string]interface{}

jsonObj.Set(10, "outter", "inner", "value")
jsonObj.SetP(20, "outter.inner.value2")
jsonObj.Set(30, "outter", "inner2", "value3")

fmt.Println(jsonObj.String())

...

Will print:

{"outter":{"inner":{"value":10,"value2":20},"inner2":{"value3":30}}}

To pretty-print:

...

fmt.Println(jsonObj.StringIndent("", "  "))

...

Will print:

{
  "outter": {
    "inner": {
      "value": 10,
      "value2": 20
    },
    "inner2": {
      "value3": 30
    }
  }
}

###Generating Arrays

...

jsonObj := gabs.New()

jsonObj.Array("foo", "array")
// Or .ArrayP("foo.array")

jsonObj.ArrayAppend(10, "foo", "array")
jsonObj.ArrayAppend(20, "foo", "array")
jsonObj.ArrayAppend(30, "foo", "array")

fmt.Println(jsonObj.String())

...

Will print:

{"foo":{"array":[10,20,30]}}

Working with arrays by index:

...

jsonObj := gabs.New()

// Create an array with the length of 3
jsonObj.ArrayOfSize(3, "foo")

jsonObj.S("foo").SetIndex("test1", 0)
jsonObj.S("foo").SetIndex("test2", 1)

// Create an embedded array with the length of 3
jsonObj.S("foo").ArrayOfSizeI(3, 2)

jsonObj.S("foo").Index(2).SetIndex(1, 0)
jsonObj.S("foo").Index(2).SetIndex(2, 1)
jsonObj.S("foo").Index(2).SetIndex(3, 2)

fmt.Println(jsonObj.String())

...

Will print:

{"foo":["test1","test2",[1,2,3]]}

###Converting back to JSON

This is the easiest part:

...

jsonParsedObj := gabs.ParseJSON([]byte(`{
	"outter":{
		"values":{
			"first":10,
			"second":11
		}
	},
	"outter2":"hello world"
}`))

jsonOutput := jsonParsedObj.String()
// Becomes `{"outter":{"values":{"first":10,"second":11}},"outter2":"hello world"}`

...

And to serialize a specific segment is as simple as:

...

jsonParsedObj := gabs.ParseJSON([]byte(`{
	"outter":{
		"values":{
			"first":10,
			"second":11
		}
	},
	"outter2":"hello world"
}`))

jsonOutput := jsonParsedObj.Search("outter").String()
// Becomes `{"values":{"first":10,"second":11}}`

...