Jonson

Fast, lightweight, thread safe, dynamic type and schema-less golang utility and easy JSON handler

Table of Contents

1. Quick start
2. Getters
3. Setters
4. Constructors
5. Types
6. Mutators
7. Converters
8. Iterators
9. Threads
10. Dependencies
11. License
12. Contact

Install

go get github.com/KromDaniel/jonson

Quick start

import "github.com/KromDaniel/jonson"

Parsing and working with JSON

json, err := jonson.Parse([]byte(`{"foo": "bar", "arr": [1,2,"str", {"nestedFooA" : "nestedBar"}]}`))
if err != nil {
    // error handler
}
// Array mapper
json.At("arr").SliceMap(func(jsn *jonson.JSON, index int) *jonson.JSON {
    // JSON numbers are always float when parsed
    if jsn.IsFloat64() {
        return jonson.New(jsn.GetUnsafeFloat64() * float64(4))
    }
    if jsn.IsString() {
        return jonson.New("_" + jsn.GetUnsafeString())
    }

    if jsn.IsMap() {
        jsn.MapSet("me", []int{1, 2, 3})
    }
    return jsn
})
// {"arr":[4,8,"_str",{"me":[1,2,3],"nestedFooA":"nestedBar"}],"foo":"bar"}
fmt.Println(json.ToUnsafeJSONString())

Creating JSON from zero

json := jonson.NewEmptyJSONMap()
json.MapSet("arr", []interface{}{1, "str", []uint16{50,60,70}})
json.MapSet("numbers", []interface{}{})

for i:=0; i < 100; i++ {
    json.At("numbers").SliceAppend(i)
}

json.At("numbers").SliceFilter(func(jsn *jonson.JSON, index int) (shouldKeep bool) {
    return IsPrime(jsn.GetUnsafeInt())
})

// {"arr":[1,"str",[50,60,70]],"numbers":[2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97]}
fmt.Println(json.ToUnsafeJSONString())

Mutating

js := jonson.New([]interface{}{55.6, 70.8, 10.4, 1, "48", "-90"})

js.SliceMap(func(jsn *jonson.JSON, index int) *jonson.JSON {
    jsn.MutateToInt()
    return jsn
}).SliceMap(func(jsn *jonson.JSON, index int) *jonson.JSON {
    if jsn.GetUnsafeInt() > 50{
        jsn.MutateToString()
    }
    return jsn
})

fmt.Println(js.ToUnsafeJSONString()) // ["55","70",10,1,48,-90]

Deep Compare

left := New(5)
right := New("5")

EqualsDeep(left, right) // false

const exampleJSON = `
[
  {
    "key": 0.8215845637650305,
    "date": "2018-05-30T13:39:19.867Z"
  },
  {
    "key": 0.8773275487707828,
    "date": "2018-04-30T13:39:19.867Z"
  }
]`

left = ParseUnsafe([]byte(testJsonString))
right = ParseUnsafe([]byte(testJsonString))

EqualsDeep(left, right) // true

left.SliceAppend(56)

EqualsDeep(left, right) // false

Getters

Getters are the way to retreive the actual value of the JSON, Since jonson is thread safe, primitive value is cloned before returned

Is type check

Jonson supports most of the reflect types each Jonson object can be asked for IsType(t reflect.Kind) or directly e.g IsInt(), IsSlice.

A legal JSON value can be one of the following types:

• string
• number
• object
• array
• boolean
• null

Jonson supports the getters IsSlice IsMap and IsPrimitive for string, number, boolean and null.

Since there are many type of numbers, There's a getter for each type e.g IsUint8 IsFloat32 or IsNumber()

Note When parsing JSON string, the default value of a number is Float64

Example

json := jonson.New("hello")
json.IsString() // true
json.IsSlice() // false
json.IsInt() // false

json := jonson.New(67.98)
json.IsNumber() // true

Value type getters

Each of reflect.Kind type has a getter and unsafe getter, unsafe getter returns the zero value for that type if type is wrong

Example

json := jonson.New(96)
isInt, val := json.GetInt()
if isInt {
    // safe, it's int
}
json.GetUnsafeFloat64() //0 value
json.GetUnsafeSlice() // 0-length []

Methods

• JSON.At(keys ...interface{}) returns a pointer to the current key, can be chained to null values
• JSON.GetSlice() returns []*jonson.JSON
• JSON.GetMap() returns map[string]*jonson.JSON
• JSON.GetObjectKeys() returns []string if JSON is map else nil
• JSON.GetSliceLen() returns int, the length of the slice if JSON is slice, else 0

Indexer (At method)

JSON.At method accepts int or string as argument, assuming string for map and int and slice, returns the zero value if wrong type

At Example

js := jonson.NewEmptyJSONMap()
js.At("KeyOfObjectWithArrayAsValue").At(12).At(54).At("key") // 12, 54 is index of slice, string is key of map
// Same as
js.At("KeyOfObjectWithArrayAsValue", 12, 54, "key")
// same as
js.At("KeyOfObjectWithArrayAsValue", 12).At(54, "key") 
// same as goes on...

Setters

Setters, just is it sounds, sets a value to current JSON

How set works

Since jonson is thread safe, it must be aware when trying to read or write a value, in order to gurantee that, value is deeply cloned, if value passed as pointer, the jonson will use the actual element it points to.

Note For better performance pass struct and map as pointer the deep clone will happen only once at the jonson cloner. Prefer using the jonson setters to avoid unnecessary operations

Methods

• JSON.SetValue(v interface{}) sets the passed value to current JSON pointer, overrides the type and the existing value
• JSON.MapSet(key string, v interface{}) sets value to current JSON as the current key (works only if current JSON is map type)
• JSON.SliceAppend(v ...interface{}) append all given values to slice (works only if current JSON is slice type)
• JSON.SliceAppendBegin(v ...interface{}) same as SliceAppend but at the start of the slice instead at the end
• JSON.SliceSet(index int, v interface{}) overrides value at specific index on slice (works only if current JSON is slice type)

Example

Deep clone understanding:

json := jonson.NewEmptyJSON() // nil value
exampleMap := make(map[string]int)
exampleMap["1"] = 1
exampleMap["2"] = 2

json.Set(&exampleMap)
exampleMap["1"] = 4

// key 1 is different value, because setters do deep clone
fmt.Println(exampleMap) // map[1:4 2:2]
fmt.Println(json.ToUnsafeJSONString()) // {"1":1,"2":2}

Faster way to create map:

json := jonson.NewEmptyJSONMap()
json.MapSet("1", 1).MapSet("2" ,2)

Constructors

Constructors are the way to initialize a new JSON object

Methods

• jonson.New(value interface{}) *JSON creates a new JSON containing the passed value
• jonson.NewEmptyJSON() *JSON creates a new empty JSON with the value of nil
• jonson.NewEmptyJSONMap() *JSON creates a new empty JSON with the value map[string]*JSON
• jonson.NewEmptyJSONArray() *JSON creates a new empty JSON with the value 0 length slice
• jonson.Parse([]byte) (error, *JSON) parses the byte (assumed to be UTF-8 JSON string)
• jonson.ParseUnsafe([]byte) *JSON same as jonson.Parse but returns the jonson.NewEmptyJSON() if error

Types

Jonson supports all valid types for JSON, here's how it works:

Map

JSON Object (key, value) is valid only for strings key, it means that only map[string]interface{} will work, a map with none string keys, the key will be ignored

Example

keyMixedMap := make(map[interface{}]interface{})
keyMixedMap[1] = "key is integer"
keyMixedMap["key"] = "key is string"

fmt.Println(jonson.New(&keyMixedMap).ToUnsafeJSONString()) //{"key":"key is string"}

Struct

Struct behaves the same as with encoding/json

Only public fields are exported, the name of the field is the key on the struct, unless there's a field descriptors with json tag json:"customKey". Public key that tagged with json:"-" it is ignored.

Note When passing a struct to Jonson, it is immediately being "Jonsonized" means the keys are converted instantly

Example

type MyStruct struct {
    Public  string
    private string
    Custom  string `json:"customKey"`
    Ignored string `json:"-"`
}

structExample := jonson.New(&MyStruct{
    Public:  "public value",
    private: "private value",
    Custom:  "custom value",
    Ignored: "Ignored value",
})

fmt.Println(structExample.At("private").IsNil()) // true
fmt.Println(structExample.ToUnsafeJSONString())  // {"Public":"public value","customKey":"custom value"}

Slice

Slice is the array type of JSON, jonson supports all kind of slices, as long as each element is JSON legal

Mutators

Mutators is a group of methods that mutates the existing JSON to different type, all the methods return bool indicates if success.

JSON with type slice or map will automatically return false

Methods

• JSON.MutateToInt() bool
• JSON.MutateToFloat() bool
• JSON.MutateToUnsignedInt() bool
• JSON.MutateToString() bool

Note MutateToFloat() converts to type float64, MutateToInt(), MutateToUnsignedInt() and MutateToString() converts to int, uint and string

Converters

Converters is a group of methods that converts the JSON object without changing it

Methods

• JSON.ToJSON() ([]byte, error) stringify the JSON to []byte
• JSON.ToUnsafeJSON() []byte stringify the JSON, if error returns empty []byte
• JSON.ToJSONString() (string, error)
• JSON.ToUnsafeJSONString() string empty string if error
• JSON.ToInterface() interface{} returns the entire JSON tree as interface
• JSON.Clone() *JSON Deep clone the current JSON tree

Iterators

Iterators is a group of methods that allows iteration on slice or map, it accepts a function as argument for callback

The methods will do nothing is JSON is not slice or map (according the relevant method)

Note Using map or filter (Similar to other languages Array.map and Array.filter), It won't return a new copy of the slice or map, it will mutate the existing one

Methods

• JSON.SliceForEach(cb func(jsn *JSON, index int)) Iterate on JSON slice
• JSON.SliceMap(cb func(jsn *JSON, index int) *JSON) Iterate on JSON slice, replacing each element with returned JSON
• JSON.SliceFilter(cb func(jsn *JSON, index int) bool) Iterate on JSON slice, removing element if cb returned false
• JSON.ObjectForEach(cb func(jsn *JSON, key string)) Iterate on JSON map
• JSON.ObjectMap(cb func(jsn *JSON, key string) *JSON) Iterate on JSON map, replacing each value with returned JSON
• JSON.ObjectFilter(cb func(jsn *JSON, key string) bool) Iterate on JSON map, removing value if cb returned false

Example

jsn := jonson.NewEmptyJSONMap()

jsn.MapSet("keyA", []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
jsn.MapSet("KeyB", 1)
jsn.MapSet("KeyC", 2)
fmt.Println(jsn.ToUnsafeJSONString()) // {"KeyB":1,"KeyC":2,"keyA":[1,2,3,4,5,6,7,8,9,10]}

// Object Map, multiply integer values * 3
jsn.ObjectMap(func(jsn *jonson.JSON, key string) *jonson.JSON {
    if jsn.IsInt() {
        return jonson.New(jsn.GetUnsafeInt() * 3)
    }
    return jsn
    // iterate on the array, keep only evens
}).At("keyA").SliceFilter(func(jsn *jonson.JSON, index int) (shouldKeep bool) {
    shouldKeep = jsn.GetUnsafeInt()%2 == 0
    return
})
fmt.Println(jsn.ToUnsafeJSONString()) // {"KeyB":3,"KeyC":6,"keyA":[2,4,6,8,10]}

Threads

Jonson managed thread safety by it self, it using read-writer mutex sync.RWMutex allowing multple readers the same time

Example

func writer(jsn *jonson.JSON, wg *sync.WaitGroup) {
	for i :=0 ; i < 100000; i++ {
		jsn.SliceAppend(i)
	}
	wg.Done()
}

func reader(jsn *jonson.JSON, wg *sync.WaitGroup) {
	time.Sleep(time.Nanosecond * 1000)
	fmt.Println("Reader", jsn.GetSliceLen())
	wg.Done()
}

func main() {
	wg := sync.WaitGroup{}
	arr := jonson.NewEmptyJSONArray()
	wg.Add(5)
	go writer(arr, &wg)
	for i:=0; i < 4; i++{
		go reader(arr, &wg)
	}
	wg.Wait()
	fmt.Println("Final len", arr.GetSliceLen())
}

/* Output
Reader 5650
Reader 5651
Reader 5652
Reader 5651
Final len 100000
*/

Dependencies

Jonson is fully free from 3rd party dependencies, the unit tests are also free of any dependencies

License

Apache 2.0

Contact

For any question or contribution, feel free to contact me at kromdan@gmail.com