Add more examples of Args field

This commit is contained in:
Albert Nigmatzianov 2017-07-26 14:51:02 +02:00
parent 4a7b7e6586
commit 8bcacfe133

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@ -487,32 +487,37 @@ More in [viper documentation](https://github.com/spf13/viper#working-with-flags)
## Positional and Custom Arguments ## Positional and Custom Arguments
Validation of positional arguments can be specified using the `Args` field. Validation of positional arguments can be specified using the `Args` field
of `Command`.
The following validators are built in: The following validators are built in:
- `NoArgs` - the command will report an error if there are any positional args. - `NoArgs` - the command will report an error if there are any positional args.
- `ArbitraryArgs` - the command will accept any args. - `ArbitraryArgs` - the command will accept any args.
- `OnlyValidArgs` - the command will report an error if there are any positional args that are not in the ValidArgs list. - `OnlyValidArgs` - the command will report an error if there are any positional args that are not in the `ValidArgs` field of `Command`.
- `MinimumNArgs(int)` - the command will report an error if there are not at least N positional args. - `MinimumNArgs(int)` - the command will report an error if there are not at least N positional args.
- `MaximumNArgs(int)` - the command will report an error if there are more than N positional args. - `MaximumNArgs(int)` - the command will report an error if there are more than N positional args.
- `ExactArgs(int)` - the command will report an error if there are not exactly N positional args. - `ExactArgs(int)` - the command will report an error if there are not exactly N positional args.
- `RangeArgs(min, max)` - the command will report an error if the number of args is not between the minimum and maximum number of expected args. - `RangeArgs(min, max)` - the command will report an error if the number of args is not between the minimum and maximum number of expected args.
A custom validator can be provided like this: An example of setting the custom validator:
```go ```go
var cmd = &cobra.Command{
Args: func validColorArgs(cmd *cobra.Command, args []string) error { Short: "hello",
if err := cli.RequiresMinArgs(1)(cmd, args); err != nil { Args: func(cmd *cobra.Command, args []string) error {
return err if len(args) < 1 {
} return errors.New("requires at least one arg")
if myapp.IsValidColor(args[0]) { }
return nil if myapp.IsValidColor(args[0]) {
} return nil
return fmt.Errorf("Invalid color specified: %s", args[0]) }
return fmt.Errorf("invalid color specified: %s", args[0])
},
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("Hello, World!")
},
} }
``` ```
## Example ## Example
@ -537,15 +542,14 @@ import (
) )
func main() { func main() {
var echoTimes int var echoTimes int
var cmdPrint = &cobra.Command{ var cmdPrint = &cobra.Command{
Use: "print [string to print]", Use: "print [string to print]",
Short: "Print anything to the screen", Short: "Print anything to the screen",
Long: `print is for printing anything back to the screen. Long: `print is for printing anything back to the screen.
For many years people have printed back to the screen. For many years people have printed back to the screen.`,
`, Args: cobra.MinimumArgs(1),
Run: func(cmd *cobra.Command, args []string) { Run: func(cmd *cobra.Command, args []string) {
fmt.Println("Print: " + strings.Join(args, " ")) fmt.Println("Print: " + strings.Join(args, " "))
}, },
@ -555,8 +559,8 @@ func main() {
Use: "echo [string to echo]", Use: "echo [string to echo]",
Short: "Echo anything to the screen", Short: "Echo anything to the screen",
Long: `echo is for echoing anything back. Long: `echo is for echoing anything back.
Echo works a lot like print, except it has a child command. Echo works a lot like print, except it has a child command.`,
`, Args: cobra.MinimumArgs(1),
Run: func(cmd *cobra.Command, args []string) { Run: func(cmd *cobra.Command, args []string) {
fmt.Println("Print: " + strings.Join(args, " ")) fmt.Println("Print: " + strings.Join(args, " "))
}, },
@ -566,7 +570,8 @@ func main() {
Use: "times [# times] [string to echo]", Use: "times [# times] [string to echo]",
Short: "Echo anything to the screen more times", Short: "Echo anything to the screen more times",
Long: `echo things multiple times back to the user by providing Long: `echo things multiple times back to the user by providing
a count and a string.`, a count and a string.`,
Args: cobra.MinimumArgs(1),
Run: func(cmd *cobra.Command, args []string) { Run: func(cmd *cobra.Command, args []string) {
for i := 0; i < echoTimes; i++ { for i := 0; i < echoTimes; i++ {
fmt.Println("Echo: " + strings.Join(args, " ")) fmt.Println("Echo: " + strings.Join(args, " "))