Formatted help text via templates

cli.go

@@ -6,7 +6,7 @@ import "os"
 var Name = os.Args[0]
 
 // Description of the program.
-var Usage = ""
+var Usage = "<No Description>"
 
 // Version of the program
 var Version = "0.0.0"
@@ -17,19 +17,19 @@ var Commands []Command = nil
 var DefaultAction = ShowHelp
 
 func Run(args []string) {
-  if len(args) > 1 {
-    command := args[1]
-    commands := CommandsWithDefaults()
-    for _, c := range commands {
-      if c.Name == command {
-        c.Action(command)
-        return
-      }
-    }
-  }
+	if len(args) > 1 {
+		command := args[1]
+		commands := CommandsWithDefaults()
+		for _, c := range commands {
+			if c.Name == command {
+				c.Action(command)
+				return
+			}
+		}
+	}
 
 	// Run default Action
-  DefaultAction("")
+	DefaultAction("")
 }
 
 func CommandsWithDefaults() []Command {

help.go

@@ -1,8 +1,17 @@
 package cli
 
-import "fmt"
 import "os"
+import "log"
+
 import "text/tabwriter"
+import "text/template"
+
+type HelpData struct {
+	Name     string
+	Usage    string
+	Commands []Command
+	Version  string
+}
 
 var HelpCommand = Command{
 	Name:      "help",
@@ -11,14 +20,43 @@ var HelpCommand = Command{
 	Action:    ShowHelp,
 }
 
+var helpTemplate = `NAME:
+  {{.Name}} - {{.Usage}}
+
+USAGE:
+  {{.Name}} [global-options] COMMAND [command-options]
+
+VERSION:
+  {{.Version}}
+
+COMMANDS:
+  {{range .Commands}}{{.Name}}{{ "\t" }}{{.Usage}}
+  {{end}}
+  
+`
+
 var ShowHelp = func(name string) {
-	w := tabwriter.NewWriter(os.Stdout, 0, 8, 1, '\t', 0)
-	fmt.Printf("Usage: %v [global-options] COMMAND [command-options]\n\n", Name)
-	if Commands != nil {
-		fmt.Printf("The most commonly used %v commands are:\n", Name)
-		for _, c := range Commands {
-			fmt.Fprintln(w, "   "+c.Name+"\t"+c.Usage)
-		}
-		w.Flush()
+
+	data := HelpData{
+		Name,
+		Usage,
+		Commands,
+		Version,
 	}
+
+	w := tabwriter.NewWriter(os.Stdout, 0, 8, 1, '\t', 0)
+	t := template.Must(template.New("help").Parse(helpTemplate))
+	err := t.Execute(w, data)
+	w.Flush()
+	if err != nil {
+		log.Println("executing template:", err)
+	}
+	// fmt.Printf("Usage: %v [global-options] COMMAND [command-options]\n\n", Name)
+	// if Commands != nil {
+	// 	fmt.Printf("The most commonly used %v commands are:\n", Name)
+	// 	for _, c := range Commands {
+	// 		fmt.Fprintln(w, "   "+c.Name+"\t"+c.Usage)
+	// 	}
+	// 	w.Flush()
+	// }
 }