Revert "Issue #219: added PreRunChain and PostRunChain hooks"

This reverts commit 3dbb5be47c.
As part of https://github.com/spf13/cobra/pull/220
PreRunChain and PostRunChain aren't required - the PersistentRun functions
need to be modified

README.md

@@ -641,22 +641,15 @@ command.SetUsageTemplate(s string)
 
 ## PreRun or PostRun Hooks
 
-It is possible to run functions before or after the main `Run` function of your command. The `PreRunChain`, `PersistentPreRun` and `PreRun` functions will be executed before `Run`. `PersistentPostRun`, `PostRun` and `PostRunChain` will be executed after `Run`.  The `Persistent*Run` functions will be inherrited by children if they do not declare their own.  These function are run in the following order:
+It is possible to run functions before or after the main `Run` function of your command. The `PersistentPreRun` and `PreRun` functions will be executed before `Run`. `PersistentPostRun` and `PostRun` will be executed after `Run`.  The `Persistent*Run` functions will be inherrited by children if they do not declare their own.  These function are run in the following order:
 
-- `PreRunChain`
 - `PersistentPreRun`
 - `PreRun`
 - `Run`
 - `PostRun`
 - `PersistentPostRun`
-- `PostRunChain`
 
-
+An example of two commands which use all of these features is below.  When the subcommand is executed, it will run the root command's `PersistentPreRun` but not the root command's `PersistentPostRun`:
-`PreRunChain` executes all PreRunChain functions from the root to the child. `PostRunChain` executes all PostRunChain functions from the child to the root. These
-are useful in cases such as setting the logger and profiling at the root level in `PreRunChain`, and stopping the profiler once the proram finishes in the `PostRunChain`, while still allowing subcommand `PreRunChain` and `PostRunChain` commands to execute for their children.
-
-An example of two commands which use all of these features is below.  When the subcommand is executed, it will run the root command's `PersistentPreRun` but not the root command's `PersistentPostRun` - because the subcommand has overridden the root command's `PersistentPostRun`. However, it will still run the root command's `PreRunChain` and `PostRunChain` in addition to the subcommand's `PreRunChain` and `PostRunChain`, because chains are supposed to execute all defined
-chain functions, and not just the overridden one.
 
 ```go
 package main
@@ -672,9 +665,6 @@ func main() {
 	var rootCmd = &cobra.Command{
 		Use:   "root [sub]",
 		Short: "My root command",
-        PreRunChain: func(cmd *cobra.Command, args []string) {
-            fmt.Printf("Inside rootCmd PreRunChain with args: %v\n", args)
-        },
 		PersistentPreRun: func(cmd *cobra.Command, args []string) {
 			fmt.Printf("Inside rootCmd PersistentPreRun with args: %v\n", args)
 		},
@@ -690,17 +680,11 @@ func main() {
 		PersistentPostRun: func(cmd *cobra.Command, args []string) {
 			fmt.Printf("Inside rootCmd PersistentPostRun with args: %v\n", args)
 		},
-        PostRunChain: func(cmd *cobra.Command, args []string) {
-            fmt.Printf("Inside rootCmd PostRunChain with args: %v\n", args)
-        },
 	}
 
 	var subCmd = &cobra.Command{
 		Use:   "sub [no options!]",
 		Short: "My subcommand",
-        PreRunChain: func(cmd *cobra.Command, args []string) {
-            fmt.Printf("Inside subCmd PreRunChain with args: %v\n", args)
-        },
 		PreRun: func(cmd *cobra.Command, args []string) {
 			fmt.Printf("Inside subCmd PreRun with args: %v\n", args)
 		},
@@ -713,9 +697,6 @@ func main() {
 		PersistentPostRun: func(cmd *cobra.Command, args []string) {
 			fmt.Printf("Inside subCmd PersistentPostRun with args: %v\n", args)
 		},
-        PostRunChain: func(cmd *cobra.Command, args []string) {
-            fmt.Printf("Inside subCmd PostRunChain with args: %v\n", args)
-        },
 	}
 
 	rootCmd.AddCommand(subCmd)
@@ -733,13 +714,11 @@ func main() {
 
 Cobra also has functions where the return signature is an error. This allows for errors to bubble up to the top, providing a way to handle the errors in one location. The current list of functions that return an error is:
 
-* PreRunChainE
 * PersistentPreRunE
 * PreRunE
 * RunE
 * PostRunE
 * PersistentPostRunE
-* PostRunChainE
 
 **Example Usage using RunE:**
 

command.go

@@ -64,18 +64,12 @@ type Command struct {
 	// Silence Usage is an option to silence usage when an error occurs.
 	SilenceUsage bool
 	// The *Run functions are executed in the following order:
-	//   * PreRunChain()
 	//   * PersistentPreRun()
 	//   * PreRun()
 	//   * Run()
 	//   * PostRun()
 	//   * PersistentPostRun()
-	//   * PostRunChain()
 	// All functions get the same args, the arguments after the command name
-	// PreRunChain: runs all PreRunChain functions from root to child sequentially
-	PreRunChain func(cmd *Command, args []string)
-	// PreRunChainE: PreRunChain but returns an error
-	PreRunChainE func(cmd *Command, args []string) error
 	// PersistentPreRun: children of this command will inherit and execute
 	PersistentPreRun func(cmd *Command, args []string)
 	// PersistentPreRunE: PersistentPreRun but returns an error
@@ -96,10 +90,6 @@ type Command struct {
 	PersistentPostRun func(cmd *Command, args []string)
 	// PersistentPostRunE: PersistentPostRun but returns an error
 	PersistentPostRunE func(cmd *Command, args []string) error
-	// PostRunChain: runs all PostRunChain functions from child to root sequentially
-	PostRunChain func(cmd *Command, args []string)
-	// PostRunChainE: PostRunChain but returns an error
-	PostRunChainE func(cmd *Command, args []string) error
 	// DisableAutoGenTag remove
 	DisableAutoGenTag bool
 	// Commands is the list of commands supported by this program.
@@ -552,10 +542,6 @@ func (c *Command) execute(a []string) (err error) {
 	c.preRun()
 	argWoFlags := c.Flags().Args()
 
-	if err := c.executePreRunChain(c, argWoFlags); err != nil {
-		return err
-	}
-
 	for p := c; p != nil; p = p.Parent() {
 		if p.PersistentPreRunE != nil {
 			if err := p.PersistentPreRunE(c, argWoFlags); err != nil {
@@ -601,10 +587,6 @@ func (c *Command) execute(a []string) (err error) {
 		}
 	}
 
-	if err := c.executePostRunChain(c, argWoFlags); err != nil {
-		return err
-	}
-
 	return nil
 }
 
@@ -614,49 +596,6 @@ func (c *Command) preRun() {
 	}
 }
 
-// executePreRunChain executes all the PreRunChain functions from
-// the root to the child.
-func (c *Command) executePreRunChain(cmd *Command, args []string) error {
-	parent := c.Parent()
-	if parent != nil {
-		if err := parent.executePreRunChain(cmd, args); err != nil {
-			return err
-		}
-	}
-
-	var err error = nil
-	switch {
-	case c.PreRunChainE != nil:
-		err = c.PreRunChainE(cmd, args)
-	case c.PreRunChain != nil:
-		c.PreRunChain(cmd, args)
-	}
-
-	return err
-}
-
-// executePostRunChain executes all the PostRunChain functions from
-// the child to the root.
-func (c *Command) executePostRunChain(cmd *Command, args []string) error {
-	var err error = nil
-	switch {
-	case c.PostRunChainE != nil:
-		err = c.PostRunChainE(cmd, args)
-	case c.PostRunChain != nil:
-		c.PostRunChain(cmd, args)
-	}
-
-	if err != nil {
-		return err
-	}
-
-	parent := c.Parent()
-	if parent != nil {
-		return parent.executePostRunChain(cmd, args)
-	}
-	return nil
-}
-
 func (c *Command) errorMsgFromParse() string {
 	s := c.flagErrorBuf.String()