cli: add play cmd

ci/release/changelogs/next.md

@@ -9,6 +9,7 @@
 - CLI: PNG output to stdout is supported using `--stdout-format png -` [#2291](https://github.com/terrastruct/d2/pull/2291)
 - Globs: `&connected` and `&leaf` filters are implemented [#2299](https://github.com/terrastruct/d2/pull/2299)
 - CLI: add --no-xml-tag for direct HTML embedding [#2302](https://github.com/terrastruct/d2/pull/2302)
+- CLI: `play` cmd added for opening d2 input in online playground [#2242](https://github.com/terrastruct/d2/pull/2242)
 
 #### Improvements 🧹
 

ci/release/template/man/d2.1

@@ -15,6 +15,8 @@
 .Ar layout Op Ar name
 .Nm d2
 .Ar fmt Ar file.d2 ...
+.Nm d2
+.Ar play Ar file.d2
 .Sh DESCRIPTION
 .Nm
 compiles and renders
@@ -141,6 +143,9 @@ Print version information and exit
 .It Fl -stdout-format Ar string
 Set the output format when writing to stdout. Supported formats are: png, svg. Only used when output is set to stdout (-)
 .Ns .
+.It Fl -no-xml-tag Ar false
+Omit XML tag (<?xml ...?>) from output SVG files. Useful when generating SVGs for direct HTML embedding
+.Ns .
 .El
 .Sh SUBCOMMANDS
 .Bl -tag -width Fl
@@ -155,10 +160,8 @@ Lists available themes
 .Ns .
 .It Ar fmt Ar file.d2 ...
 Format all passed files
-.It Fl -no-xml-tag Ar false
-Omit XML tag (<?xml ...?>) from output SVG files. Useful when generating SVGs for direct HTML embedding
-.Ns .
-.Ns .
+.It Ar play Ar file.d2
+Opens the file in playground, an online web viewer (https://play.d2lang.com)
 .El
 .Sh ENVIRONMENT VARIABLES
 Many flags can also be set with environment variables.

d2cli/help.go

@@ -22,6 +22,7 @@ Usage:
   %[1]s [--watch=false] [--theme=0] file.d2 [file.svg | file.png]
   %[1]s layout [name]
   %[1]s fmt file.d2 ...
+  %[1]s play [--theme=0] [--sketch] file.d2
 
 %[1]s compiles and renders file.d2 to file.svg | file.png
 It defaults to file.svg if an output path is not provided.
@@ -38,6 +39,7 @@ Subcommands:
   %[1]s layout [name] - Display long help for a particular layout engine, including its configuration options
   %[1]s themes - Lists available themes
   %[1]s fmt file.d2 ... - Format passed files
+	%[1]s play file.d2 - Opens the file in playground, an online web viewer (https://play.d2lang.com)
 
 See more docs and the source code at https://oss.terrastruct.com/d2.
 Hosted icons at https://icons.terrastruct.com.

d2cli/main.go

@@ -171,6 +171,8 @@ func Run(ctx context.Context, ms *xmain.State) (err error) {
 			return nil
 		case "fmt":
 			return fmtCmd(ctx, ms, *checkFlag)
+		case "play":
+			return playCmd(ctx, ms)
 		case "version":
 			if len(ms.Opts.Flags.Args()) > 1 {
 				return xmain.UsageErrorf("version subcommand accepts no arguments")

d2cli/play.go

@@ -0,0 +1,75 @@
+package d2cli
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+
+	"oss.terrastruct.com/d2/lib/urlenc"
+	"oss.terrastruct.com/util-go/xbrowser"
+	"oss.terrastruct.com/util-go/xmain"
+)
+
+func playCmd(ctx context.Context, ms *xmain.State) error {
+	if len(ms.Opts.Flags.Args()) != 2 {
+		return xmain.UsageErrorf("play must be passed one argument: either a filepath or '-' for stdin")
+	}
+	filepath := ms.Opts.Flags.Args()[1]
+
+	theme, err := ms.Opts.Flags.GetInt64("theme")
+	if err != nil {
+		return err
+	}
+
+	sketch, err := ms.Opts.Flags.GetBool("sketch")
+	if err != nil {
+		return err
+	}
+
+	var sketchNumber int
+	if sketch {
+		sketchNumber = 1
+	} else {
+		sketchNumber = 0
+	}
+
+	fileRaw, err := readInput(filepath)
+	if err != nil {
+		return err
+	}
+
+	encoded, err := urlenc.Encode(fileRaw)
+	if err != nil {
+		return err
+	}
+
+	url := fmt.Sprintf("https://play.d2lang.com/?script=%s&sketch=%d&theme=%d&", encoded, sketchNumber, theme)
+	openBrowser(ctx, ms, url)
+	return nil
+}
+
+func readInput(filepath string) (string, error) {
+	if filepath == "-" {
+		data, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			return "", fmt.Errorf("error reading from stdin: %w", err)
+		}
+		return string(data), nil
+	}
+
+	data, err := os.ReadFile(filepath)
+	if err != nil {
+		return "", xmain.UsageErrorf(err.Error())
+	}
+	return string(data), nil
+}
+
+func openBrowser(ctx context.Context, ms *xmain.State, url string) {
+	ms.Log.Info.Printf("opening playground: %s", url)
+
+	err := xbrowser.Open(ctx, ms.Env, url)
+	if err != nil {
+		ms.Log.Warn.Printf("failed to open browser to %v: %v", url, err)
+	}
+}