gocnab

gocnab implements encoding and decoding of CNAB (Centro Nacional de Automação Bancária) data as defined by FEBRABAN.

When marshaling it is possible to inform a struct, that will generate 1 CNAB line, or a slice of struct to generate multiple CNAB lines. On unmarshal a pointer to a struct, a pointer to a slice of struct or a mapper (map[string]interface{} for a full CNAB file) should be used.

The library use struct tags to define the position of the field in the CNAB content [begin,end). It supports the basic attribute types string (uppercase and left align), bool (represented by 1 or 0), int, int8, int16, int32, int64, uint, uint8, uint16, uint23, uint64, float32 and float64 (decimal separator removed). And for custom types it is possible to implement gocnab.Marshaler, gocnab.Unmarshaler, encoding.TextMarshaler and encoding.TextUnmarshaler to make full use of this library.

Install

go get -u github.com/rafaeljusto/gocnab

Usage

For working with only a single line of the CNAB file:

package main

import "github.com/rafaeljusto/gocnab"

type example struct {
	FieldA int     `cnab:"0,20"`
	FieldB string  `cnab:"20,50"`
	FieldC float64 `cnab:"50,60"`
	FieldD uint    `cnab:"60,70"`
	FieldE bool    `cnab:"70,71"`
}

func main() {
	e1 := example{
		FieldA: 123,
		FieldB: "THIS IS A TEST",
		FieldC: 50.30,
		FieldD: 445,
		FieldE: true,
	}

	data, err := gocnab.Marshal400(e1)
	if err != nil {
		println(err)
		return
	}

	var e2 example
	if err = gocnab.Unmarshal(data, &e2); err != nil {
		println(err)
		return
	}

	println(e1 == e2)
}

And for the whole CNAB file:

package main

import "github.com/rafaeljusto/gocnab"

type header struct {
	Identifier string `cnab:"0,1"`
	HeaderA    int    `cnab:"1,5"`
}

type content struct {
	Identifier string  `cnab:"0,1"`
	FieldA     int     `cnab:"1,20"`
	FieldB     string  `cnab:"20,50"`
	FieldC     float64 `cnab:"50,60"`
	FieldD     uint    `cnab:"60,70"`
	FieldE     bool    `cnab:"70,71"`
}

type footer struct {
	Identifier string `cnab:"0,1"`
	FooterA    string `cnab:"5,30"`
}

func main() {
	h1 := header{
		Identifier: "0",
		HeaderA:    2,
	}

	c1 := []content{
		{
			Identifier: "1",
			FieldA:     123,
			FieldB:     "THIS IS A TEXT",
			FieldC:     50.30,
			FieldD:     445,
			FieldE:     true,
		},
		{
			Identifier: "1",
			FieldA:     321,
			FieldB:     "THIS IS ANOTHER TEXT",
			FieldC:     30.50,
			FieldD:     544,
			FieldE:     false,
		},
	}

	f1 := footer{
		Identifier: "2",
		FooterA:    "FINAL TEXT",
	}

	data, err := gocnab.Marshal400(h1, c1, f1)
	if err != nil {
		println(err)
		return
	}

	var h2 header
	var c2 []content
	var f2 footer

	if err = gocnab.Unmarshal(data, map[string]interface{}{
		"0": &h2,
		"1": &c2,
		"2": &f2,
	}); err != nil {
		println(err)
		return
	}

	println(h1 == h2)
	for i := range c1 {
		println(c1[i] == c2[i])
	}
	println(f1 == f2)
}