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https://github.com/Eun/go-convert

Convert a value into another type
https://github.com/Eun/go-convert

go golang

Last synced: 24 days ago
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Convert a value into another type

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README 

        
# go-convert [![Actions Status](https://github.com/Eun/go-convert/workflows/CI/badge.svg)](https://github.com/Eun/go-convert/actions) [![Coverage Status](https://coveralls.io/repos/github/Eun/go-convert/badge.svg?branch=master)](https://coveralls.io/github/Eun/go-convert?branch=master) [![PkgGoDev](https://img.shields.io/badge/pkg.go.dev-reference-blue)](https://pkg.go.dev/github.com/Eun/go-convert) [![GoDoc](https://godoc.org/github.com/Eun/go-convert?status.svg)](https://godoc.org/github.com/Eun/go-convert) [![go-report](https://goreportcard.com/badge/github.com/Eun/go-convert)](https://goreportcard.com/report/github.com/Eun/go-convert)

Convert a value into another type.



```bash

go get -u github.com/Eun/go-convert

```

## Usage

```go

package main



import (

	"fmt"



	"github.com/Eun/go-convert"

)



func main() {

	// convert a int to a string

	var s string

	convert.MustConvert(1, &s)

	fmt.Printf("%s\n", s)



	// convert a map into a struct

	type User struct {

		ID   int

		Name string

	}

	var u User

	convert.MustConvert(map[string]string{

		"Name": "Joe",

		"ID":   "10",

	}, &u)

	fmt.Printf("%#v\n", u)



	// convert Id to int and Groups to []int and keep the rest

	m := map[string]interface{}{

		"Id":     0,

		"Groups": []int{},

	}

	// convert a map into well defined map

	convert.MustConvert(

		map[string]interface{}{

			"Id":      "1",

			"Name":    "Joe",

			"Groups":  []string{"3", "6"},

			"Country": "US",

		},

		&m,

	)

	fmt.Printf("%v\n", m)



	// convert a interface slice into well defined interface slice

	// making the first one an integer, the second a string and the third an float

	sl := []interface{}{0, "", 0.0}

	convert.MustConvert([]string{"1", "2", "3"}, &sl)

	fmt.Printf("%v\n", sl)

}



```



## Recipe system

_go-convert_ uses a recipe system that defines how and which types should be converted in which type.

A lot of recipes are already builtin (see [recipes.go](recipes.go)), however you can add your own or overwrite the builtin ones.

```go

package main



import (

	"fmt"

	"strings"



	"github.com/Eun/go-convert"

)



type Roles struct {

	IsAdmin     bool

	IsDeveloper bool

}



type User struct {

	ID    int

	Name  string

	Roles Roles

}



func main() {

	// this is the data we want to convert

	data := map[string]string{

		"id":    "10",

		"Name":  "Joe",

		"roles": "AD", // this user is Admin (A) and Developer (D)

	}



	// create a converter

	conv := convert.New(convert.Options{

		Recipes: convert.MustMakeRecipes(

			// convert string into Roles

			func(_ convert.Converter, in string, out *Roles) error {

				(*out).IsAdmin = false

				(*out).IsDeveloper = false

				if strings.Contains(in, "A") {

					(*out).IsAdmin = true

				}

				if strings.Contains(in, "D") {

					(*out).IsDeveloper = true

				}

				return nil

			},

		),

	})



	var user User

	conv.MustConvert(data, &user)

	// user is now an instance of User

	fmt.Printf("%#v\n", user)

}



```



## Adding inline recipes

You can also add recipes inline by implementing a `ConvertRecipes() []Recipe` function.  

Example:

```go

package main



import (

	"fmt"

	"strings"



	"github.com/Eun/go-convert"

)



type Roles struct {

	IsAdmin     bool

	IsDeveloper bool

}



type User struct {

	ID    int

	Name  string

	Roles Roles

}



func (user *User) ConvertRecipes() []convert.Recipe {

	return convert.MustMakeRecipes(

		// convert string into Roles

		func(_ convert.Converter, in string, out *Roles) error {

			out.IsAdmin = false

			out.IsDeveloper = false

			if strings.Contains(in, "A") {

				out.IsAdmin = true

			}

			if strings.Contains(in, "D") {

				out.IsDeveloper = true

			}

			return nil

		},

	)

}



func main() {

	// this is the data we want to convert

	data := []map[string]string{

		{

			"id":    "10",

			"Name":  "Joe",

			"roles": "AD", // this user is Admin (A) and Developer (D)

		},

		{

			"id":    "21",

			"Name":  "Alice",

			"roles": "D", // this user is Developer (D)

		},

	}



	var users []User

	convert.MustConvert(data, &users)

	// users is now an instance of []User

	fmt.Printf("%#v\n", users)

}



```



### Notice

This library is using reflection so be aware it might be slow in your usecase.