go-bo4e

Business Objects for Energy (BO4E) Implementation in Go. Highlights are

• includes json tags for easy (un)marshalling
• comes with builtin validator logic
• is linted and has decent test coverage

Installation

go get github.com/hochfrequenz/go-bo4e

Minimal Working Example

package main

import (
	"encoding/json"
	"fmt"
	"github.com/go-playground/validator/v10"
	"github.com/hochfrequenz/go-bo4e/bo"
	"github.com/hochfrequenz/go-bo4e/com"
	"github.com/hochfrequenz/go-bo4e/enum/botyp"
	"github.com/hochfrequenz/go-bo4e/enum/landescode"
	"github.com/hochfrequenz/go-bo4e/enum/sparte"
)

func main() {
	melo := bo.Messlokation{
		Geschaeftsobjekt: bo.Geschaeftsobjekt{
			BoTyp:             botyp.MESSLOKATION,
			VersionStruktur:   "1",
			ExterneReferenzen: nil,
		},
		MesslokationsId: "DE0000011111222223333344444555556",
		Sparte:          sparte.STROM,
		Messadresse: &com.Adresse{
			Postleitzahl: "82031",
			Ort:          "Grünwald",
			Strasse:      "Nördliche Münchner Straße",
			Hausnummer:   "27A",
			Landescode:   landescode.DE,
		},
	}
	vali := validator.New()
	err := vali.Struct(melo)
	if err == nil {
		fmt.Println("The MeLo is valid.")
	}
	meloBytes, err := json.Marshal(melo)
	meloJson := string(meloBytes)
	fmt.Print(meloJson)
}

Use this in the Go Playground.

Caveats

When serializing decimals (e.g. Zaehlwerk.Wandlerfaktor) you'll notice that the decimals are by default serialized as
strings

{
  "wandlerfaktor": "0.8"
}

instead of a number like

{
  "wandlerfaktor": 0.8
}

This is the default behaviour defined in
the decimal package
. You can change the behaviour by setting

decimal.MarshalJSONWithoutQuotes = true

as described f.e. in issue 21 there.

Other Noteworthy BO4E Implementations

• C# / .NET
• Python
• Kotlin
• TypeScript (handcrafted)
• TypeScript (autogenerated from C# lib)

Contributing

Contributions are welcome. Feel free to open a Pull Request against the main branch of this repository. Please provide
unit tests if you contribute logic beyond bare business object definitions. We do track our modification proposals
to the official BO4E standard in a separate
repository: BO4E-modification-proposals.

Adding Enums

When adding Enums there are two packages (stringer
, jsonenums) needed to go-generate additional files, which contain an
implementation of the fmt.Stringer and json.Marshaler interface for the respective enum. Since they are just needed
for the code generation, but not a real dependency we don't want them in the go.mod file. One way to install them is
outside of your directory with:

go install github.com/campoy/jsonenums@latest
go install golang.org/x/tools/cmd/stringer@latest

Hochfrequenz

Hochfrequenz Unternehmensberatung GmbH is a Grünwald (near Munich) based consulting
company with offices in Berlin and Bremen. We're not only the main contributor to open source BO4E software but,
according to Kununu ratings, also among the most
attractive employers within the German energy market. Applications of talented developers are welcome at any time!
Please consider visiting
our career page (
German only).