k3s/vendor/k8s.io/cli-runtime/pkg/genericclioptions/json_yaml_flags.go

/*
Copyright 2018 The Kubernetes Authors.

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

    http://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 genericclioptions

import (
	"strings"

	"github.com/spf13/cobra"

	"k8s.io/cli-runtime/pkg/printers"
)

// AllowedFormats returns slice of string of allowed JSONYaml printing format
func (f *JSONYamlPrintFlags) AllowedFormats() []string {
	if f == nil {
		return []string{}
	}
	return []string{"json", "yaml"}
}

// JSONYamlPrintFlags provides default flags necessary for json/yaml printing.
// Given the following flag values, a printer can be requested that knows
// how to handle printing based on these values.
type JSONYamlPrintFlags struct {
	showManagedFields bool
}

// ToPrinter receives an outputFormat and returns a printer capable of
// handling --output=(yaml|json) printing.
// Returns false if the specified outputFormat does not match a supported format.
// Supported Format types can be found in pkg/printers/printers.go
func (f *JSONYamlPrintFlags) ToPrinter(outputFormat string) (printers.ResourcePrinter, error) {
	var printer printers.ResourcePrinter

	outputFormat = strings.ToLower(outputFormat)
	switch outputFormat {
	case "json":
		printer = &printers.JSONPrinter{}
	case "yaml":
		printer = &printers.YAMLPrinter{}
	default:
		return nil, NoCompatiblePrinterError{OutputFormat: &outputFormat, AllowedFormats: f.AllowedFormats()}
	}

	if !f.showManagedFields {
		printer = &printers.OmitManagedFieldsPrinter{Delegate: printer}
	}
	return printer, nil
}

// AddFlags receives a *cobra.Command reference and binds
// flags related to JSON or Yaml printing to it
func (f *JSONYamlPrintFlags) AddFlags(c *cobra.Command) {
	if f == nil {
		return
	}

	c.Flags().BoolVar(&f.showManagedFields, "show-managed-fields", f.showManagedFields, "If true, keep the managedFields when printing objects in JSON or YAML format.")
}

// NewJSONYamlPrintFlags returns flags associated with
// yaml or json printing, with default values set.
func NewJSONYamlPrintFlags() *JSONYamlPrintFlags {
	return &JSONYamlPrintFlags{}
}