wire through humanreadable flags

pkg/printers/humanreadable_flags.go

@@ -0,0 +1,123 @@
+/*
+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 printers
+
+import (
+	"github.com/spf13/cobra"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/kubernetes/pkg/kubectl/scheme"
+)
+
+// HumanPrintFlags provides default flags necessary for printing.
+// Given the following flag values, a printer can be requested that knows
+// how to handle printing based on these values.
+type HumanPrintFlags struct {
+	ShowKind     *bool
+	ShowLabels   *bool
+	SortBy       *string
+	ColumnLabels *[]string
+
+	// get.go-specific values
+	NoHeaders bool
+
+	Kind               schema.GroupKind
+	AbsoluteTimestamps bool
+	WithNamespace      bool
+}
+
+// ToPrinter receives an outputFormat and returns a printer capable of
+// handling human-readable output.
+func (f *HumanPrintFlags) ToPrinter(outputFormat string) (ResourcePrinter, bool, error) {
+	if len(outputFormat) > 0 && outputFormat != "wide" {
+		return nil, false, nil
+	}
+
+	encoder := scheme.Codecs.LegacyCodec(scheme.Registry.EnabledVersions()...)
+	decoder := scheme.Codecs.UniversalDecoder()
+
+	showKind := false
+	if f.ShowKind != nil {
+		showKind = *f.ShowKind
+	}
+
+	showLabels := false
+	if f.ShowLabels != nil {
+		showLabels = *f.ShowLabels
+	}
+
+	columnLabels := []string{}
+	if f.ColumnLabels != nil {
+		columnLabels = *f.ColumnLabels
+	}
+
+	p := NewHumanReadablePrinter(encoder, decoder, PrintOptions{
+		Kind:          f.Kind,
+		WithKind:      showKind,
+		NoHeaders:     f.NoHeaders,
+		Wide:          outputFormat == "wide",
+		WithNamespace: f.WithNamespace,
+		ColumnLabels:  columnLabels,
+		ShowLabels:    showLabels,
+	})
+
+	// TODO(juanvallejo): enable this here once we wire commands to instantiate PrintFlags directly.
+	// PrintHandlers are currently added through cmd/util/printing.go#PrinterForOptions
+	//printersinternal.AddHandlers(p)
+
+	// TODO(juanvallejo): handle sorting here
+
+	return p, true, nil
+}
+
+// AddFlags receives a *cobra.Command reference and binds
+// flags related to human-readable printing to it
+func (f *HumanPrintFlags) AddFlags(c *cobra.Command) {
+	if f.ShowLabels != nil {
+		c.Flags().BoolVar(f.ShowLabels, "show-labels", *f.ShowLabels, "When printing, show all labels as the last column (default hide labels column)")
+	}
+	if f.SortBy != nil {
+		c.Flags().StringVar(f.SortBy, "sort-by", *f.SortBy, "If non-empty, sort list types using this field specification.  The field specification is expressed as a JSONPath expression (e.g. '{.metadata.name}'). The field in the API resource specified by this JSONPath expression must be an integer or a string.")
+	}
+	if f.ColumnLabels != nil {
+		c.Flags().StringSliceVarP(f.ColumnLabels, "label-columns", "L", *f.ColumnLabels, "Accepts a comma separated list of labels that are going to be presented as columns. Names are case-sensitive. You can also use multiple flag options like -L label1 -L label2...")
+	}
+	if f.ShowKind != nil {
+		c.Flags().BoolVar(f.ShowKind, "show-kind", *f.ShowKind, "If present, list the resource type for the requested object(s).")
+	}
+}
+
+// NewHumanPrintFlags returns flags associated with
+// human-readable printing, with default values set.
+func NewHumanPrintFlags(kind schema.GroupKind, noHeaders, withNamespace, absoluteTimestamps bool) *HumanPrintFlags {
+	showLabels := false
+	sortBy := ""
+	showKind := false
+	columnLabels := []string{}
+
+	return &HumanPrintFlags{
+		NoHeaders:          noHeaders,
+		WithNamespace:      withNamespace,
+		AbsoluteTimestamps: absoluteTimestamps,
+		ColumnLabels:       &columnLabels,
+
+		Kind:       kind,
+		ShowLabels: &showLabels,
+		SortBy:     &sortBy,
+		ShowKind:   &showKind,
+	}
+}