cnfgfile

The cnfgfile.Unmarshal() procedure can be used in place of: xml.Unmarshal, json.Unmarshal, yaml.Unmarshal and toml.Unmarshal. This procedure also reads in the provided file, so you don't need to do any of the io work beforehand. Using this procedure in your app allows your consumers to a use a config file format of their choosing. Very cool stuff when you consider _that file_ could just be a config file for a larger project.

package main

import (
	"fmt"
	"os"

	"golift.io/cnfg"
	"golift.io/cnfgfile"
)

func main() {
	// Recommend adding tags for each type to your struct members. Provide full compatibility.
	type Config struct {
		Interval cnfg.Duration `json:"interval" xml:"interval" toml:"interval" yaml:"interval"`
		Location string        `json:"location" xml:"location" toml:"location" yaml:"location"`
		Provided bool          `json:"provided" xml:"provided" toml:"provided" yaml:"provided"`
	}

	// Create a test file with some test data to unmarshal.
	// YAML is just an example, you can use any supported format.
	path, err := os.CreateTemp("", "test_config_file.yaml")
	if err != nil {
		panic(err)
	}

	yaml := "---\ninterval: 5m\nlocation: Earth\nprovided: true\n"
	if _, err = fmt.Fprint(path, yaml); err != nil {
		panic(err)
	}

	path.Close()

	// Start with an empty config. Or set some defaults beforehand.
	config := &Config{}

	// Simply pass in your config file. If it contains ".yaml" it will be parsed as YAML.
	// Same for ".xml" and ".json". If the file has none of these extensions it is parsed
	// as TOML. Meaning if you name your config "config.conf" it needs ot be TOML formatted.
	err = cnfgfile.Unmarshal(config, path.Name())
	if err != nil {
		panic(err)
	}

	fmt.Printf("interval: %v, location: %v, provided: %v", config.Interval, config.Location, config.Provided)
}

Output:

interval: 5m, location: Earth, provided: true