From faf2a3d4a3371d302c16b4a751571d95ea732679 Mon Sep 17 00:00:00 2001
From: Summer Mousa <smousa@zenoss.com>
Date: Wed, 16 Apr 2014 15:26:28 -0500
Subject: [PATCH] Added Before method to command.  If set, or if
 command.Subcommands is set, then the command is treated as a recursive
 subcommand

---
 app.go     |  7 +++++++
 command.go | 12 ++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/app.go b/app.go
index f9342d7..a4a76ef 100644
--- a/app.go
+++ b/app.go
@@ -171,6 +171,13 @@ func (a *App) RunAsSubcommand(c *Context) error {
 		return nil
 	}
 
+	if a.Before != nil {
+		err := a.Before(context)
+		if err != nil {
+			return err
+		}
+	}
+
 	args := context.Args()
 	if args.Present() {
 		name := args.First()
diff --git a/command.go b/command.go
index 2d5c662..735505b 100644
--- a/command.go
+++ b/command.go
@@ -18,17 +18,20 @@ type Command struct {
 	Description string
 	// The function to call when checking for bash command completions
 	BashComplete func(context *Context)
+	// An action to execute before any sub-subcommands are run, but after the context is ready
+	// If a non-nil error is returned, no sub-subcommands are run
+	Before func(context *Context) error
 	// The function to call when this command is invoked
 	Action func(context *Context)
-	// List of flags to parse
-	Flags []Flag
 	// List of child commands
 	Subcommands []Command
+	// List of flags to parse
+	Flags []Flag
 }
 
 // Invokes the command given the context, parses ctx.Args() to generate command-specific flags
 func (c Command) Run(ctx *Context) error {
-	if len(c.Subcommands) > 0 {
+	if (c.Subcommands != nil && len(c.Subcommands) > 0) || c.Before != nil {
 		return c.startApp(ctx)
 	}
 
@@ -117,7 +120,8 @@ func (c Command) startApp(ctx *Context) error {
 		app.BashComplete = c.BashComplete
 	}
 
-	// set the action
+	// set the actions
+	app.Before = c.Before
 	if c.Action != nil {
 		app.Action = c.Action
 	} else {