Method RegisterFlagCompletionFunc

completions.go:170–183

RegisterFlagCompletionFunc should be called to register a function to provide completion for a flag. You can use pre-defined completion functions such as [FixedCompletions] or [NoFileCompletions], or you can define your own.

(flagName string, f CompletionFunc)

// You can use pre-defined completion functions such as [FixedCompletions] or [NoFileCompletions],
// or you can define your own.
func (c *Command) RegisterFlagCompletionFunc(flagName string, f CompletionFunc) error {
	flag := c.Flag(flagName)
	if flag == nil {
		return fmt.Errorf("RegisterFlagCompletionFunc: flag '%s' does not exist", flagName)
	}
	flagCompletionMutex.Lock()
	defer flagCompletionMutex.Unlock()

	if _, exists := flagCompletionFunctions[flag]; exists {
		return fmt.Errorf("RegisterFlagCompletionFunc: flag '%s' already registered", flagName)
	}
	flagCompletionFunctions[flag] = f
	return nil
}

// GetFlagCompletionFunc returns the completion function for the given flag of the command, if available.
func (c *Command) GetFlagCompletionFunc(flagName string) (CompletionFunc, bool) {