refactor: add stdout to metadata handlers

Signed-off-by: Billy Zha <[email protected]>

cmd/oras/internal/display/handler.go

@@ -40,13 +40,13 @@ func NewPushHandler(format string, tty *os.File, out io.Writer, verbose bool) (s
 	var metadataHandler metadata.PushHandler
 	switch format {
 	case "":
-		metadataHandler = text.NewPushHandler()
+		metadataHandler = text.NewPushHandler(out)
 	case "json":
-		metadataHandler = json.NewPushHandler()
+		metadataHandler = json.NewPushHandler(out)
 	default:
-		metadataHandler = template.NewPushHandler(format)
+		metadataHandler = template.NewPushHandler(format, out)
 	}
-	metadataHandler.WithOutput(out)
+
 	return statusHandler, metadataHandler
 }
 
@@ -64,12 +64,12 @@ func NewAttachHandler(format string, tty *os.File, out io.Writer, verbose bool)
 	var metadataHandler metadata.AttachHandler
 	switch format {
 	case "":
-		metadataHandler = text.NewAttachHandler()
+		metadataHandler = text.NewAttachHandler(out)
 	case "json":
-		metadataHandler = json.NewAttachHandler()
+		metadataHandler = json.NewAttachHandler(out)
 	default:
-		metadataHandler = template.NewAttachHandler(format)
+		metadataHandler = template.NewAttachHandler(format, out)
 	}
-	metadataHandler.WithOutput(out)
+
 	return statusHandler, metadataHandler
 }

cmd/oras/internal/display/metadata/interface.go

@@ -17,19 +17,16 @@ package metadata
 
 import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // PushHandler handles metadata output for push events.
 type PushHandler interface {
 	OnCopied(opts *option.Target) error
 	OnCompleted(root ocispec.Descriptor) error
-	view.Outputable
 }
 
 // AttachHandler handles metadata output for attach events.
 type AttachHandler interface {
 	OnCompleted(opts *option.Target, root, subject ocispec.Descriptor) error
-	view.Outputable
 }

cmd/oras/internal/display/metadata/json/attach.go

@@ -16,26 +16,27 @@ limitations under the License.
 package json
 
 import (
+	"io"
+
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
 	"oras.land/oras/cmd/oras/internal/display/metadata/model"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // AttachHandler handles json metadata output for attach events.
 type AttachHandler struct {
-	view.Printer
+	out io.Writer
 }
 
 // NewAttachHandler creates a new handler for attach events.
-func NewAttachHandler() metadata.AttachHandler {
+func NewAttachHandler(out io.Writer) metadata.AttachHandler {
 	return &AttachHandler{
-		Printer: view.NewPrinter(),
+		out: out,
 	}
 }
 
 // OnCompleted is called when the attach command is completed.
 func (a *AttachHandler) OnCompleted(opts *option.Target, root, subject ocispec.Descriptor) error {
-	return a.PrintJSON(model.NewPush(root, opts.Path))
+	return printJSON(a.out, model.NewPush(root, opts.Path))
 }

cmd/oras/internal/display/metadata/json/json.go

@@ -0,0 +1,27 @@
+/*
+Copyright The ORAS 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 json
+
+import (
+	"encoding/json"
+	"io"
+)
+
+func printJSON(out io.Writer, object any) error {
+	encoder := json.NewEncoder(out)
+	encoder.SetIndent("", "  ")
+	return encoder.Encode(object)
+}

cmd/oras/internal/display/metadata/json/push.go

@@ -16,23 +16,24 @@ limitations under the License.
 package json
 
 import (
+	"io"
+
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
 	"oras.land/oras/cmd/oras/internal/display/metadata/model"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // PushHandler handles JSON metadata output for push events.
 type PushHandler struct {
 	path string
-	view.Printer
+	out  io.Writer
 }
 
 // NewPushHandler creates a new handler for push events.
-func NewPushHandler() metadata.PushHandler {
+func NewPushHandler(out io.Writer) metadata.PushHandler {
 	return &PushHandler{
-		Printer: view.NewPrinter(),
+		out: out,
 	}
 }
 
@@ -44,5 +45,5 @@ func (ph *PushHandler) OnCopied(opts *option.Target) error {
 
 // OnCompleted is called after the push is completed.
 func (ph *PushHandler) OnCompleted(root ocispec.Descriptor) error {
-	return ph.PrintJSON(model.NewPush(root, ph.path))
+	return printJSON(ph.out, model.NewPush(root, ph.path))
 }

cmd/oras/internal/display/metadata/template/attach.go

@@ -16,28 +16,29 @@ limitations under the License.
 package template
 
 import (
+	"io"
+
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
 	"oras.land/oras/cmd/oras/internal/display/metadata/model"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // AttachHandler handles go-template metadata output for attach events.
 type AttachHandler struct {
 	template string
-	view.Printer
+	out      io.Writer
 }
 
 // NewAttachHandler returns a new handler for attach metadata events.
-func NewAttachHandler(template string) metadata.AttachHandler {
+func NewAttachHandler(template string, out io.Writer) metadata.AttachHandler {
 	return &AttachHandler{
-		Printer:  view.NewPrinter(),
+		out:      out,
 		template: template,
 	}
 }
 
 // OnCompleted formats the metadata of attach command.
 func (ah *AttachHandler) OnCompleted(opts *option.Target, root, subject ocispec.Descriptor) error {
-	return ah.ParseAndWrite(model.NewPush(root, opts.Path), ah.template)
+	return parseAndWrite(ah.out, model.NewPush(root, opts.Path), ah.template)
 }

cmd/oras/internal/display/metadata/template/push.go

@@ -16,24 +16,25 @@ limitations under the License.
 package template
 
 import (
+	"io"
+
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
 	"oras.land/oras/cmd/oras/internal/display/metadata/model"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // PushHandler handles go-template metadata output for push events.
 type PushHandler struct {
 	template string
 	path     string
-	view.Printer
+	out      io.Writer
 }
 
 // NewPushHandler returns a new handler for push events.
-func NewPushHandler(template string) metadata.PushHandler {
+func NewPushHandler(template string, out io.Writer) metadata.PushHandler {
 	return &PushHandler{
-		Printer:  view.NewPrinter(),
+		out:      out,
 		template: template,
 	}
 }
@@ -46,5 +47,5 @@ func (ph *PushHandler) OnCopied(opts *option.Target) error {
 
 // OnCompleted is called after the push is completed.
 func (ph *PushHandler) OnCompleted(root ocispec.Descriptor) error {
-	return ph.ParseAndWrite(model.NewPush(root, ph.path), ph.template)
+	return parseAndWrite(ph.out, model.NewPush(root, ph.path), ph.template)
 }

cmd/oras/internal/display/metadata/template/template.go

@@ -0,0 +1,31 @@
+/*
+Copyright The ORAS 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 template
+
+import (
+	"io"
+	"text/template"
+
+	"github.com/Masterminds/sprig/v3"
+)
+
+func parseAndWrite(out io.Writer, object any, templateStr string) error {
+	t, err := template.New("format output").Funcs(sprig.FuncMap()).Parse(templateStr)
+	if err != nil {
+		return err
+	}
+	return t.Execute(out, object)
+}

cmd/oras/internal/display/metadata/text/attach.go

@@ -17,23 +17,23 @@ package text
 
 import (
 	"fmt"
+	"io"
 	"strings"
 
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // AttachHandler handles text metadata output for attach events.
 type AttachHandler struct {
-	view.Printer
+	out io.Writer
 }
 
 // NewAttachHandler returns a new handler for attach events.
-func NewAttachHandler() metadata.AttachHandler {
+func NewAttachHandler(out io.Writer) metadata.AttachHandler {
 	return &AttachHandler{
-		Printer: view.NewPrinter(),
+		out: out,
 	}
 }
 
@@ -43,10 +43,10 @@ func (a *AttachHandler) OnCompleted(opts *option.Target, root, subject ocispec.D
 	if !strings.HasSuffix(opts.RawReference, digest) {
 		opts.RawReference = fmt.Sprintf("%s@%s", opts.Path, subject.Digest)
 	}
-	_, err := a.Println("Attached to", opts.AnnotatedReference())
+	_, err := fmt.Fprintln(a.out, "Attached to", opts.AnnotatedReference())
 	if err != nil {
 		return err
 	}
-	_, err = a.Println("Digest:", root.Digest)
+	_, err = fmt.Fprintln(a.out, "Digest:", root.Digest)
 	return err
 }

cmd/oras/internal/display/metadata/text/push.go

@@ -16,32 +16,34 @@ limitations under the License.
 package text
 
 import (
+	"fmt"
+	"io"
+
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
-	"oras.land/oras/cmd/oras/internal/display/metadata/view"
 	"oras.land/oras/cmd/oras/internal/option"
 )
 
 // PushHandler handles text metadata output for push events.
 type PushHandler struct {
-	view.Printer
+	out io.Writer
 }
 
 // NewPushHandler returns a new handler for push events.
-func NewPushHandler() metadata.PushHandler {
+func NewPushHandler(out io.Writer) metadata.PushHandler {
 	return &PushHandler{
-		Printer: view.NewPrinter(),
+		out: out,
 	}
 }
 
 // OnCopied is called after files are copied.
 func (p *PushHandler) OnCopied(opts *option.Target) error {
-	_, err := p.Println("Pushed", opts.AnnotatedReference())
+	_, err := fmt.Fprintln(p.out, "Pushed", opts.AnnotatedReference())
 	return err
 }
 
 // OnCompleted is called after the push is completed.
 func (p *PushHandler) OnCompleted(root ocispec.Descriptor) error {
-	_, err := p.Println("Digest:", root.Digest)
+	_, err := fmt.Fprintln(p.out, "Digest:", root.Digest)
 	return err
 }