SuggestedValuesFn wip

api.go

@@ -240,6 +240,20 @@ ARGS_LOOP:
 									}
 								}
 							}
+							if lastOpt.SuggestedValuesFn != nil {
+								for _, e := range lastOpt.SuggestedValuesFn(completionMode, strings.SplitN(iterator.Value(), "=", 2)[1]) {
+									c := fmt.Sprintf("--%s=%s", k, e)
+									if strings.HasPrefix(c, iterator.Value()) {
+										// NOTE: Bash completions have = as a special char and results should be trimmed form the = on.
+										if completionMode == "bash" {
+											tc := strings.SplitN(c, "=", 2)[1]
+											completions = append(completions, tc)
+										} else {
+											completions = append(completions, c)
+										}
+									}
+								}
+							}
 						}
 					}
 					sort.Strings(completions)

examples/complex/complete/complete.go

@@ -2,8 +2,10 @@ package complete
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"log"
+	"os"
 	"strings"
 
 	"github.com/DavidGamba/go-getoptions"
@@ -15,6 +17,10 @@ var Logger = log.New(io.Discard, "log ", log.LstdFlags)
 func NewCommand(parent *getoptions.GetOpt) *getoptions.GetOpt {
 	opt := parent.NewCommand("complete", "Example completions")
 	opt.SetCommandFn(Run)
+	opt.String("completeme", "", opt.SuggestedValuesFn(func(target, partial string) []string {
+		fmt.Fprintf(os.Stderr, "\npartial: %v\n", partial)
+		return []string{"complete", "completeme", "completeme2"}
+	}))
 	opt.ArgCompletions("dev-east", "dev-west", "staging-east", "prod-east", "prod-west", "prod-south")
 	opt.ArgCompletionsFns(func(target string, prev []string, s string) []string {
 		if len(prev) == 0 {

internal/option/option.go

@@ -30,6 +30,10 @@ var ErrorMissingRequiredOption = errors.New("")
 // Handler - Signature for the function that handles saving to the option.
 type Handler func(optName string, argument string, usedAlias string) error
 
+// ValueCompletionsFn - Function receiver for custom completions.
+// The `target` argument indicates "bash" or "zsh" for the completion targets.
+type ValueCompletionsFn func(target string, partialCompletion string) []string
+
 // Type - Indicates the type of option.
 type Type int
 
@@ -72,8 +76,9 @@ type Option struct {
 
 	// SuggestedValues used for completions, suggestions don't necessarily limit
 	// the values you are able to use
-	SuggestedValues []string
-	ValidValues     []string // ValidValues that can be passed to Save
+	SuggestedValues   []string
+	ValidValues       []string // ValidValues that can be passed to Save
+	SuggestedValuesFn ValueCompletionsFn
 
 	// Help
 	DefaultStr   string // String representation of default value

user_options.go

@@ -142,6 +142,13 @@ func (gopt *GetOpt) SuggestedValues(values ...string) ModifyFn {
 	}
 }
 
+// SuggestedValuesFn - adds a dynamic list of suggestions to the autocompletion for the option.
+func (gopt *GetOpt) SuggestedValuesFn(fn option.ValueCompletionsFn) ModifyFn {
+	return func(parent *GetOpt, opt *option.Option) {
+		opt.SuggestedValuesFn = fn
+	}
+}
+
 // Called - Indicates if the option was passed on the command line.
 // If the `name` is an option that wasn't declared it will return false.
 func (gopt *GetOpt) Called(name string) bool {