Add TOML config file loader

altsrc/toml_file_loader.go

@@ -0,0 +1,113 @@
+// Disabling building of toml support in cases where golang is 1.0 or 1.1
+// as the encoding library is not implemented or supported.
+
+// +build go1.2
+
+package altsrc
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/BurntSushi/toml"
+	"github.com/urfave/cli"
+)
+
+type TomlMap struct {
+	Map map[interface{}]interface{}
+}
+
+func unmarshalMap(i interface{}) (ret map[interface{}]interface{}, err error) {
+	ret = make(map[interface{}]interface{})
+	m := i.(map[string]interface{})
+	for key, val := range m {
+		v := reflect.ValueOf(val)
+		switch v.Kind() {
+		case reflect.Bool:
+			ret[key] = val.(bool)
+		case reflect.String:
+			ret[key] = val.(string)
+		case reflect.Int:
+			ret[key] = int(val.(int))
+		case reflect.Int8:
+			ret[key] = int(val.(int8))
+		case reflect.Int16:
+			ret[key] = int(val.(int16))
+		case reflect.Int32:
+			ret[key] = int(val.(int32))
+		case reflect.Int64:
+			ret[key] = int(val.(int64))
+		case reflect.Uint:
+			ret[key] = int(val.(uint))
+		case reflect.Uint8:
+			ret[key] = int(val.(uint8))
+		case reflect.Uint16:
+			ret[key] = int(val.(uint16))
+		case reflect.Uint32:
+			ret[key] = int(val.(uint32))
+		case reflect.Uint64:
+			ret[key] = int(val.(uint64))
+		case reflect.Float32:
+			ret[key] = float64(val.(float32))
+		case reflect.Float64:
+			ret[key] = float64(val.(float64))
+		case reflect.Map:
+			if tmp, err := unmarshalMap(val); err == nil {
+				ret[key] = tmp
+			} else {
+				return nil, err
+			}
+		case reflect.Array:
+			fallthrough // [todo] - Support array type
+		default:
+			return nil, fmt.Errorf("Unsupported: type = %#v", v.Kind())
+		}
+	}
+	return ret, nil
+}
+
+func (self *TomlMap) UnmarshalTOML(i interface{}) error {
+	if tmp, err := unmarshalMap(i); err == nil {
+		self.Map = tmp
+	} else {
+		return err
+	}
+	return nil
+}
+
+type tomlSourceContext struct {
+	FilePath string
+}
+
+// NewTomlSourceFromFile creates a new TOML InputSourceContext from a filepath.
+func NewTomlSourceFromFile(file string) (InputSourceContext, error) {
+	tsc := &tomlSourceContext{FilePath: file}
+	var results TomlMap = TomlMap{}
+	if err := readCommandToml(tsc.FilePath, &results); err != nil {
+		return nil, fmt.Errorf("Unable to load TOML file '%s': inner error: \n'%v'", tsc.FilePath, err.Error())
+	}
+	return &MapInputSource{valueMap: results.Map}, nil
+}
+
+// NewTomlSourceFromFlagFunc creates a new TOML InputSourceContext from a provided flag name and source context.
+func NewTomlSourceFromFlagFunc(flagFileName string) func(context *cli.Context) (InputSourceContext, error) {
+	return func(context *cli.Context) (InputSourceContext, error) {
+		filePath := context.String(flagFileName)
+		return NewTomlSourceFromFile(filePath)
+	}
+}
+
+func readCommandToml(filePath string, container interface{}) (err error) {
+	b, err := loadDataFrom(filePath)
+	if err != nil {
+		return err
+	}
+
+	err = toml.Unmarshal(b, container)
+	if err != nil {
+		return err
+	}
+
+	err = nil
+	return
+}