Feature: Make Formatters Pluggable (Again)

.github/workflows/test.yml

@@ -14,27 +14,42 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.19.x]
+        go-version: [stable,oldstable]
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Install Go
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v4
         with:
           go-version: ${{ matrix.go-version }}
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Test
         run: go test ./...
+  runexamples:
+    strategy:
+      matrix:
+        go-version: [stable,oldstable]
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go-version }}
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Test Examples
+        run: for EX in $(ls _examples); do go run ./_examples/$EX; done
   coverage:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 2
-      - uses: actions/setup-go@v2
+      - uses: actions/setup-go@v4
         with:
-          go-version: '1.19.x'
+          go-version: 'stable'
       - name: Run coverage
         run: go test -race -coverprofile=coverage.txt -covermode=atomic
       - name: Upload coverage to Codecov

README.md

@@ -70,27 +70,6 @@ w.MustPrint(struct {
 // {"FirstName":"Bob","LastName":"Ross"}
 ```
 
-### Cobra Integration
-
-To simplify using this in new projects, you can use the `NewWithCobraCmd`
-method. Example:
-
-```go
-// By default, look for a field called 'format'
-w, err := NewWithCobraCmd(cmd, nil)
-```
-
-```go
-// Or pass a configuration object with what the field is called
-w, err := NewWithCobraCmd(cmd, &gout.CobraCmdConfig{
-        FormatField: "my-special-name-field",
-})
-```
-
-By default, the gout will use os.Stdout as the default writer.
-
-See [_examples](_examples/) for more example usage
-
 ## Built-in Formatters
 
 ### YAML

_examples/basic/main.go

@@ -1,19 +1,19 @@
 package main
 
 import (
+	"fmt"
 	"os"
 
 	gout "github.com/drewstinnett/gout/v2"
-	"github.com/drewstinnett/gout/v2/formats/json"
+	"github.com/drewstinnett/gout/v2/formats"
+	_ "github.com/drewstinnett/gout/v2/formats/builtin"
 )
 
 func main() {
-	w, err := gout.New()
-	if err != nil {
-		panic(err)
-	}
+	w := gout.New()
+	fmt.Printf("Active Formatters: %v\n", formats.Names())
 	// By Default, the YAML format is use, Let's change it to json though
-	w.SetFormatter(json.Formatter{})
+	// w.SetFormatter(json.Formatter{})
 
 	// By Default, print to stdout. Let's change it to stderr though
 	w.SetWriter(os.Stderr)

_examples/formats/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	gout "github.com/drewstinnett/gout/v2"
+	"github.com/drewstinnett/gout/v2/formats"
 )
 
 type sample struct {
@@ -21,19 +22,17 @@ func main() {
 		sample{FirstName: "Freddy", LastName: "Krueger", Age: 35},
 		sample{FirstName: "Michael", LastName: "Myers", Age: 13},
 	}
-	c, _ := gout.New()
-	for formatN, formatF := range gout.BuiltInFormatters {
-		if formatN != "gotemplate" {
-			fmt.Printf("# Format: %v\n", formatN)
-			c.SetFormatter(formatF)
-			// CSV Formatter won't work on a single object, has to be iterable
-			if formatN != "csv" {
-				fmt.Println("## Person")
-				c.MustPrint(person)
-			}
-			fmt.Println("## People")
-			c.MustPrint(people)
-			fmt.Println()
+	g := gout.New()
+	for formatN, formatG := range formats.Formats {
+		fmt.Printf("# Format: %v\n", formatN)
+		g.SetFormatter(formatG())
+		// CSV Formatter won't work on a single object, has to be iterable
+		if formatN != "csv" {
+			fmt.Println("## Person")
+			g.MustPrint(person)
 		}
+		fmt.Println("## People")
+		g.MustPrint(people)
+		fmt.Println()
 	}
 }

_examples/gotemplate/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	gout "github.com/drewstinnett/gout/v2"
+	"github.com/drewstinnett/gout/v2/config"
 	"github.com/drewstinnett/gout/v2/formats/gotemplate"
 )
 
@@ -21,12 +22,15 @@ func main() {
 		sample{FirstName: "Freddy", LastName: "Krueger", Age: 35},
 		sample{FirstName: "Michael", LastName: "Myers", Age: 13},
 	}
-	c, _ := gout.New()
-	c.SetFormatter(gotemplate.Formatter{
-		Template: "{{ range . }}{{ .FirstName }} {{ .LastName }} is {{ .Age }} years old\n{{ end }}",
+	g := gout.New()
+	g.SetFormatter(gotemplate.Formatter{
+		Opts: config.FormatterOpts{
+			"template": "{{ range . }}{{ .FirstName }} {{ .LastName }} is {{ .Age }} years old\n{{ end }}",
+		},
 	})
+	//"template": "{{ range . }}{{ .FirstName }} {{ .LastName }} is {{ .Age }} years old\n{{ end }}",
 	fmt.Printf("# Format: gotemplate\n## People\n")
-	c.MustPrint(people)
+	g.MustPrint(people)
 	fmt.Println()
 
 	// fmt.Println(string(b))

formats/builtin/builtin.go

@@ -0,0 +1,12 @@
+/*
+Package builtin is a helper to  register all the built in formatters
+*/
+package builtin
+
+import (
+	_ "github.com/drewstinnett/gout/v2/formats/gotemplate"
+	_ "github.com/drewstinnett/gout/v2/formats/json"
+	_ "github.com/drewstinnett/gout/v2/formats/plain"
+	_ "github.com/drewstinnett/gout/v2/formats/xml"
+	_ "github.com/drewstinnett/gout/v2/formats/yaml"
+)

formats/gotemplate/gotemplate.go

@@ -6,6 +6,7 @@ import (
 	"text/template"
 
 	"github.com/drewstinnett/gout/v2/config"
+	"github.com/drewstinnett/gout/v2/formats"
 )
 
 type Formatter struct {
@@ -35,22 +36,8 @@ func (w Formatter) Format(v interface{}) ([]byte, error) {
 	return doc.Bytes(), nil
 }
 
-/*
-func (w Formatter) formatWithOpts(v interface{}, o config.FormatterOpts) ([]byte, error) {
-	if _, ok := o["template"]; !ok {
-		return nil, errors.New("Must pass 'template' in to options")
-	}
-
-	tpl := o["template"].(string)
-	var doc bytes.Buffer
-	tmpl, err := template.New("item").Parse(tpl)
-	if err != nil {
-		return nil, err
-	}
-	err = tmpl.Execute(&doc, v)
-	if err != nil {
-		return nil, err
-	}
-	return doc.Bytes(), nil
+func init() {
+	formats.Add("gotemplate", func() formats.Formatter {
+		return &Formatter{}
+	})
 }
-*/

formats/json/json.go

@@ -3,6 +3,8 @@ package json
 import (
 	"context"
 	ujson "encoding/json"
+
+	"github.com/drewstinnett/gout/v2/formats"
 )
 
 type Formatter struct {
@@ -30,3 +32,9 @@ func (w *Formatter) withContext(ctx context.Context) *Formatter {
 	w.ctx = ctx
 	return w
 }
+
+func init() {
+	formats.Add("json", func() formats.Formatter {
+		return &Formatter{}
+	})
+}

formats/plain/plain.go

@@ -2,10 +2,18 @@ package plain
 
 import (
 	"fmt"
+
+	"github.com/drewstinnett/gout/v2/formats"
 )
 
 type Formatter struct{}
 
 func (w Formatter) Format(v interface{}) ([]byte, error) {
 	return []byte(fmt.Sprintf("%+v\n", v)), nil
 }
+
+func init() {
+	formats.Add("plain", func() formats.Formatter {
+		return &Formatter{}
+	})
+}

formats/registry.go

@@ -0,0 +1,29 @@
+package formats
+
+import (
+	"sort"
+)
+
+type Creator func() Formatter
+
+var Formats = map[string]Creator{}
+
+// Add a new format creator
+func Add(name string, creator Creator) {
+	Formats[name] = creator
+}
+
+// Names returns a slice of the names of the formatters
+func Names() []string {
+	ret := []string{}
+	for k := range Formats {
+		ret = append(ret, k)
+	}
+	sort.Strings(ret)
+	return ret
+}
+
+// Formatter interface that defines how a thing can be formatted for output
+type Formatter interface {
+	Format(interface{}) ([]byte, error)
+}

formats/registry_test.go

@@ -0,0 +1,17 @@
+package formats_test
+
+import (
+	"testing"
+
+	"github.com/drewstinnett/gout/v2/formats"
+	_ "github.com/drewstinnett/gout/v2/formats/builtin"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuiltinRegistry(t *testing.T) {
+	require.Equal(
+		t,
+		[]string{"gotemplate", "json", "plain", "xml", "yaml"},
+		formats.Names(),
+	)
+}

formats/xml/xml.go

@@ -2,10 +2,18 @@ package xml
 
 import (
 	uxml "encoding/xml"
+
+	"github.com/drewstinnett/gout/v2/formats"
 )
 
 type Formatter struct{}
 
 func (w Formatter) Format(v interface{}) ([]byte, error) {
 	return uxml.Marshal(v)
 }
+
+func init() {
+	formats.Add("xml", func() formats.Formatter {
+		return &Formatter{}
+	})
+}