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}}`
...### Parsing Numbers
Gabs uses the json package under the bonnet, which by default will parse all number values into float64. If you need to parse Int values then you should use a json.Decoder (https://golang.org/pkg/encoding/json/#Decoder):
sample := []byte(`{"test":{"int":10, "float":6.66}}`)
dec := json.NewDecoder(bytes.NewReader(sample))
dec.UseNumber()
val, err := gabs.ParseJSONDecoder(dec)
if err != nil {
t.Errorf("Failed to parse: %v", err)
return
}
intValue, err := val.Path("test.int").Data().(json.Number).Int64()