niljson/README.md
Winni Neessen 05d806adff
Add JSON marshaling support for Variable types
Introduced a NewVariable function for creating generics-based Variable types. Added MarshalJSON methods to support JSON encoding for various Nil types, ensuring proper handling of nil values. Updated tests and examples to verify the new marshaling functionality.
2024-09-02 12:13:54 +02:00

3.7 KiB

niljson - A simple Go package for unmarshalling null-able JSON types

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niljson provides a simple and efficient way to handle nullable JSON fields during the unmarshalling process. In JSON, it's common to encounter fields that can be null, but handling these fields in Go can be cumbersome, especially when dealing with primitive types like int, float64, bool. These types can all be either 0 (as value) or null. In Go you can always work with pointers but these, of course, can lead to unhandled nil pointer dereferences.

niljaon addresses this challenge by offering a set of types that can seamlessly handle null values during unmarshalling, allowing your Go applications to work with JSON data more naturally and with fewer boilerplate checks for nil values.

Key Features

  • Nullable Types: Provides a range of nullable types (NilString, NilInt, NilFloat, NilBool, etc.) that are easy to use and integrate into your existing Go structs.
  • Seamless Integration: These types work just like Go's standard types but add support for null values, enabling cleaner and more maintainable code.
  • JSON Unmarshalling Support: Automatically handles the unmarshalling of JSON fields, converting null JSON values to Go's nil or zero values, depending on the context.
  • Minimalistic and Lightweight: Designed to be lightweight and unobtrusive, so it won't bloat your application or introduce unnecessary dependencies (only relies on the Go standard library)

Example Usage

package main

import (
    "encoding/json"
    "fmt"
    "os"
    
    "github.com/wneessen/niljson"
)

type JSONType struct {
    Bool       niljson.NilBoolean `json:"bool"`
    Float32    niljson.NilFloat32 `json:"float32,omitempty"`
    Float64    niljson.NilFloat64 `json:"float64"`
    Int        niljson.NilInt     `json:"int"`
    Int64      niljson.NilInt64   `json:"int64"`
    NullString niljson.NilString  `json:"nil"`
    String     niljson.NilString  `json:"string"`
}

func main() {
  data := []byte(`{
 		"bytes": "Ynl0ZXM=",
		"bool": true,
		"float32": null,
		"float64":0,
		"int": 123,
		"int64": 12345678901234,
		"nilvalue": null,
		"string":"test"
	}`)

  var example JSONType
  var output string
  if err := json.Unmarshal(data, &example); err != nil {
    fmt.Println("failed to unmarshal JSON:", err)
    os.Exit(1)
  }

  if example.Bool.NotNil() {
    output += fmt.Sprintf("Bool is: %t, ", example.Bool.Value())
  }
  if example.Float32.IsNil() {
    output += "Float 32 is nil, "
  }
  if example.Float64.NotNil() {
    output += fmt.Sprintf("Float 64 is: %f, ", example.Float64.Value())
  }
  if example.String.NotNil() {
    output += fmt.Sprintf("String is: %s", example.String.Value())
  }
  fmt.Println(output)
  
  data, err := json.Marshal(&example)
  if err != nil {
    fmt.Printf("failed to marshal JSON: %s", err)
    os.Exit(1)
  }
  fmt.Println(data)
}