copygen

Example: Error

The error example uses templates to return a nil error from the mapping function.

./domain/domain.go

// Package domain contains business logic models.
package domain

// Account represents a user account.
type Account struct {
	ID     int
	UserID string
	Name   string
	Other  string // The other field is not used.
}

./models/model.go

// Package models contains data storage models (i.e database).
package models

// Account represents the data model for account.
type Account struct {
	ID       int
	Name     string
	Password string
	Email    string
}

// A User represents the data model for a user.
type User struct {
	UserID   int
	Name     int
	UserData string
}

YML

# Define where the code will be generated.
generated:
  setup: ./setup.go
  output: ../copygen.go

  # Define the optional custom templates used to generate the file (.go, .tmpl supported).
  template: ../template/generate.go

# Define custom options (which are passed to generator options) for customization.
custom:
  option: The possibilities are endless.

The error example ignores the custom fields (loaded as a Generator Option).

Go

// Package copygen contains the setup information for copygen generated code.
package copygen

import (
	c "strconv"

	"github.com/switchupcb/copygen/examples/main/domain"
	"github.com/switchupcb/copygen/examples/main/models"
)

// Copygen defines the functions that will be generated.
type Copygen interface {
	// custom see table in the README for options
	ModelsToDomain(*models.Account, *models.User) *domain.Account
}

/* Define the function and field this converter is applied to using regex. */
// convert .* models.User.UserID
// Itoa converts an integer to an ascii value.
func Itoa(i int) string {
	return c.Itoa(i)
}

Use pointers to avoid allocations.

Output

copygen -yml path/to/yml

// Code generated by github.com/switchupcb/copygen
// DO NOT EDIT.

// Package copygen contains the setup information for copygen generated code.
package copygen

import (
	c "strconv"

	"github.com/switchupcb/copygen/examples/error/domain"
	"github.com/switchupcb/copygen/examples/error/models"
)

/* Define the function and field this converter is applied to using regex. */
// Itoa converts an integer to an ascii value.
func Itoa(i int) string {
	return c.Itoa(i)
}

// ModelsToDomain copies a *models.Account, *models.User to a *domain.Account.
func ModelsToDomain(tA *domain.Account, fA *models.Account, fU *models.User) error {
	// *domain.Account fields
	tA.ID = fA.ID
	tA.UserID = Itoa(fU.UserID)
	tA.Name = fA.Name

	return nil
}