pkg/converter/encoder.go

// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package converter

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/ghodss/yaml"
)

// FromObject creates a converting encodeer from an object.
func FromObject(obj interface{}) *Encoder {
	return &Encoder{obj}
}

// Encoder converts from an object to some serialized format for the object.
type Encoder struct {
	obj interface{}
}

func (m *Encoder) encode(format ContentType) ([]byte, error) {
	switch format {
	case YAML:
		return yaml.Marshal(m.obj)
	case JSON:
		return json.Marshal(m.obj)
	default:
		return nil, fmt.Errorf("unknown content type: %q", format)
	}
}

// ToYAML converts an object to YAML bytes slice
func (m *Encoder) ToYAML() ([]byte, error) {
	return m.encode(YAML)
}

// ToYAMLString converts an object to YAML string
func (m *Encoder) ToYAMLString() (string, error) {
	yamlBytes, err := m.encode(YAML)
	return string(yamlBytes[:]), err
}

// ToJSON converts an object to JSON bytes slice
func (m *Encoder) ToJSON() ([]byte, error) {
	return m.encode(JSON)
}

// ToJSONString converts an object to JSON string
func (m *Encoder) ToJSONString() (string, error) {
	jsonBytes, err := m.encode(JSON)
	return string(jsonBytes[:]), err
}

// ToContentType converts to a custom content type.
func (m *Encoder) ToContentType(ctype string) ([]byte, error) {
	lower := strings.ToLower(ctype)
	return m.encode(ContentType(lower))
}