example_test.go

package multiconfig

import (
	"fmt"
	"os"
)

func ExampleDefaultLoader() {
	// Our struct which is used for configuration
	type ServerConfig struct {
		Name    string `default:"gopher"`
		Port    int    `default:"6060"`
		Enabled bool
		Users   []string
	}

	// Instantiate a default loader.
	d := NewWithPath("testdata/config.toml")

	s := &ServerConfig{}

	// It first sets the default values for each field with tag values defined
	// with "default", next it reads from config.toml, from environment
	// variables and finally from command line flags. It panics if loading fails.
	d.MustLoad(s)

	fmt.Println("Host-->", s.Name)
	fmt.Println("Port-->", s.Port)

	// Output:
	// Host--> koding
	// Port--> 6060

}

func ExampleMultiLoader() {
	// Our struct which is used for configuration
	type ServerConfig struct {
		Name     string
		Port     int
		Enabled  bool
		Users    []string
		Postgres Postgres
	}

	os.Setenv("SERVERCONFIG_NAME", "koding")
	os.Setenv("SERVERCONFIG_PORT", "6060")

	// Create a custom multi loader intance based on your needs.
	f := &FlagLoader{}
	e := &EnvironmentLoader{}

	l := MultiLoader(f, e)

	// Load configs into our s variable from the sources above
	s := &ServerConfig{}
	err := l.Load(s)
	if err != nil {
		panic(err)
	}

	fmt.Println("Host-->", s.Name)
	fmt.Println("Port-->", s.Port)

	// Output:
	// Host--> koding
	// Port--> 6060
}

func ExampleEnvironmentLoader() {
	// Our struct which is used for configuration
	type ServerConfig struct {
		Name     string
		Port     int
		Enabled  bool
		Users    []string
		Postgres Postgres
	}

	// Assume those values defined before running the Loader
	os.Setenv("SERVERCONFIG_NAME", "koding")
	os.Setenv("SERVERCONFIG_PORT", "6060")

	// Instantiate loader
	l := &EnvironmentLoader{}

	s := &ServerConfig{}
	err := l.Load(s)
	if err != nil {
		panic(err)
	}

	fmt.Println("Host-->", s.Name)
	fmt.Println("Port-->", s.Port)

	// Output:
	// Host--> koding
	// Port--> 6060
}

func ExampleTOMLLoader() {
	// Our struct which is used for configuration
	type ServerConfig struct {
		Name     string
		Port     int
		Enabled  bool
		Users    []string
		Postgres Postgres
	}

	// Instantiate loader
	l := &TOMLLoader{Path: testTOML}

	s := &ServerConfig{}
	err := l.Load(s)
	if err != nil {
		panic(err)
	}

	fmt.Println("Host-->", s.Name)
	fmt.Println("Users-->", s.Users)

	// Output:
	// Host--> koding
	// Users--> [ankara istanbul]
}

func ExampleJSONLoader() {
	// Our struct which is used for configuration
	type ServerConfig struct {
		Name     string
		Port     int
		Enabled  bool
		Users    []string
		Postgres Postgres
	}

	// Instantiate loader
	l := &JSONLoader{Path: testJSON}

	s := &ServerConfig{}
	err := l.Load(s)
	if err != nil {
		panic(err)
	}

	fmt.Println("Host-->", s.Name)
	fmt.Println("Users-->", s.Users)

	// Output:
	// Host--> koding
	// Users--> [ankara istanbul]
}

func ExampleYAMLLoader() {
	// Our struct which is used for configuration
	type ServerConfig struct {
		Name     string
		Port     int
		Enabled  bool
		Users    []string
		Postgres Postgres
	}

	// Instantiate loader
	l := &YAMLLoader{Path: testYAML}

	s := &ServerConfig{}
	err := l.Load(s)
	if err != nil {
		panic(err)
	}

	fmt.Println("Host-->", s.Name)
	fmt.Println("Users-->", s.Users)

	// Output:
	// Host--> koding
	// Users--> [ankara istanbul]
}