Goverter

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Setting: map ​

map [SOURCE-PATH] TARGET [| FUNC] can be defined as method comment.

map SOURCE-FIELD TARGET ​

If the source and target struct have differently named fields, then you can use map to define the mapping.

go
package example

// goverter:converter
type Converter interface {
	// goverter:map LastName Surname
	Convert(Input) Output
}

type Input struct {
	Age      int
	LastName string
}
type Output struct {
	Age     int
	Surname string
}
go
// Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
//go:build !goverter

package generated

import mapfield "github.com/jmattheis/goverter/example/map-field"

type ConverterImpl struct{}

func (c *ConverterImpl) Convert(source mapfield.Input) mapfield.Output {
	var exampleOutput mapfield.Output
	exampleOutput.Age = source.Age
	exampleOutput.Surname = source.LastName
	return exampleOutput
}

map SOURCE-PATH TARGET ​

You can access nested properties by separating the field names with .:

go
// goverter:converter
type Converter interface {
    // goverter:map Nested.LastName Surname
    Convert(Input) Output
}
Example (click to expand)
go
package example

// goverter:converter
type Converter interface {
	// goverter:map Nested.LastName Surname
	Convert(Input) Output
}

type Input struct {
	Age    int
	Nested NestedInput
}
type NestedInput struct {
	LastName string
}
type Output struct {
	Age     int
	Surname string
}
go
// Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
//go:build !goverter

package generated

import mappath "github.com/jmattheis/goverter/example/map-path"

type ConverterImpl struct{}

func (c *ConverterImpl) Convert(source mappath.Input) mappath.Output {
	var exampleOutput mappath.Output
	exampleOutput.Age = source.Age
	exampleOutput.Surname = source.Nested.LastName
	return exampleOutput
}

map DOT TARGET ​

map . TARGET

When using . as source field inside map, then you the instruct Goverter to use the source struct as source for the conversion to the target property. This is useful, when you've a struct that is the flattened version of another struct. See autoMap for the invert operation of this.

go
package example

// goverter:converter
type Converter interface {
	// goverter:map . Address
	Convert(FlatPerson) Person
}

type FlatPerson struct {
	Name    string
	Age     int
	Street  string
	ZipCode string
}
type Person struct {
	Name    string
	Age     int
	Address Address
}
type Address struct {
	Street  string
	ZipCode string
}
go
// Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
//go:build !goverter

package generated

import mapidentity "github.com/jmattheis/goverter/example/map-identity"

type ConverterImpl struct{}

func (c *ConverterImpl) Convert(source mapidentity.FlatPerson) mapidentity.Person {
	var examplePerson mapidentity.Person
	examplePerson.Name = source.Name
	examplePerson.Age = source.Age
	examplePerson.Address = c.exampleFlatPersonToExampleAddress(source)
	return examplePerson
}
func (c *ConverterImpl) exampleFlatPersonToExampleAddress(source mapidentity.FlatPerson) mapidentity.Address {
	var exampleAddress mapidentity.Address
	exampleAddress.Street = source.Street
	exampleAddress.ZipCode = source.ZipCode
	return exampleAddress
}

map [SOURCE-PATH] TARGET | [PACKAGE:]FUNC ​

For [SOURCE-PATH] TARGET you can use everything that's described above in this document. The FUNC may have the signatures described in Signature: Optional Source.

You can optionally define the PACKAGE where FUNC is located by separating the PACKAGE and FUNC with a :(colon). If no package is defined, then the package of the conversion method is used.

go
package example

// goverter:converter
type Converter interface {
	// goverter:map URL | PrependHTTPS
	// goverter:map . FullName | GetFullName
	// goverter:map Age | DefaultAge
	// goverter:map Value | strconv:Itoa
	Convert(Input) (Output, error)
}

type Input struct {
	URL string

	FirstName string
	LastName  string

	Value int
}
type Output struct {
	URL      string
	FullName string
	Age      int

	Value string
}

func GetFullName(input Input) string {
	return input.FirstName + " " + input.LastName
}
func PrependHTTPS(url string) string { return "https://" + url }
func DefaultAge() int                { return 42 }
go
// Code generated by github.com/jmattheis/goverter, DO NOT EDIT.
//go:build !goverter

package generated

import (
	mapcustom "github.com/jmattheis/goverter/example/map-custom"
	"strconv"
)

type ConverterImpl struct{}

func (c *ConverterImpl) Convert(source mapcustom.Input) (mapcustom.Output, error) {
	var exampleOutput mapcustom.Output
	exampleOutput.URL = mapcustom.PrependHTTPS(source.URL)
	exampleOutput.FullName = mapcustom.GetFullName(source)
	exampleOutput.Age = mapcustom.DefaultAge()
	exampleOutput.Value = strconv.Itoa(source.Value)
	return exampleOutput, nil
}