Survey
A library for building interactive prompts. Heavily inspired by the great inquirer.js.
package main
import (
"fmt"
"github.com/tj/survey"
)
// the questions to ask
var qs = []*survey.Question{
{
Name: "name",
Prompt: &survey.Input{Message: "What is your name?"},
Validate: survey.Required,
},
{
Name: "color",
Prompt: &survey.Select{
Message: "Choose a color:",
Options: []string{"red", "blue", "green"},
Default: "red",
},
},
{
Name: "age",
Prompt: &survey.Input{Message: "How old are you?"},
},
}
func main() {
// the answers will be written to this struct
answers := struct {
Name string // survey will match the question and field names
FavoriteColor string `survey:"color"` // or you can tag fields to match a specific name
Age int // if the types don't match exactly, survey will try to convert for you
}{}
// perform the questions
err := survey.Ask(qs, &answers)
if err != nil {
fmt.Println(err.Error())
return
}
fmt.Printf("%s chose %s.", answers.Name, answers.FavoriteColor)
}Table of Contents
Examples
Examples can be found in the examples/ directory. Run them
to see basic behavior:
go get github.com/tj/survey
# ... navigate to the repo in your GOPATH
go run examples/simple.go
go run examples/validation.goPrompts
Input
name := ""
prompt := &survey.Input{
Message: "ping",
}
survey.AskOne(prompt, &name, nil)Password
password := ""
prompt := &survey.Password{
Message: "Please type your password",
}
survey.AskOne(prompt, &password, nil)Confirm
name := false
prompt := &survey.Confirm{
Message: "Do you like pie?",
}
survey.AskOne(prompt, &name, nil)Select
color := ""
prompt := &survey.Select{
Message: "Choose a color:",
Options: []string{"red", "blue", "green"},
}
survey.AskOne(prompt, &color, nil)By default, the select prompt is limited to showing 7 options at a time
and will paginate lists of options longer than that. To increase, you can either
change the global survey.PageCount, or set the PageSize field on the prompt:
prompt := &survey.Select{..., PageSize: 10}MultiSelect
days := []string{}
prompt := &survey.MultiSelect{
Message: "What days do you prefer:",
Options: []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"},
}
survey.AskOne(prompt, &days, nil)By default, the MultiSelect prompt is limited to showing 7 options at a time
and will paginate lists of options longer than that. To increase, you can either
change the global survey.PageCount, or set the PageSize field on the prompt:
prompt := &survey.MultiSelect{..., PageSize: 10}Editor
Launches the user's preferred editor (defined by the $EDITOR environment variable) on a temporary file. Once the user exits their editor, the contents of the temporary file are read in as the result. If neither of those are present, notepad (on Windows) or vim (Linux or Mac) is used.
Validation
Validating individual responses for a particular question can be done by defining a
Validate field on the survey.Question to be validated. This function takes an
interface{} type and returns an error to show to the user, prompting them for another
response:
q := &survey.Question{
Prompt: &survey.Input{Message: "Hello world validation"},
Validate: func (val interface{}) error {
// since we are validating an Input, the assertion will always succeed
if str, ok := val.(string) ; ok && len(str) > 10 {
return errors.New("This response cannot be longer than 10 characters.")
}
}
}Built-in Validators
survey comes prepackaged with a few validators to fit common situations. Currently these
validators include:
| name | valid types | description |
|---|---|---|
| Required | any | Rejects zero values of the response type |
| MinLength(n) | string | Enforces that a response is at least the given length |
| MaxLength(n) | string | Enforces that a response is no longer than the given length |
Help Text
All of the prompts have a Help field which can be defined to provide more information to your users:
&survey.Input{
Message: "What is your phone number:",
Help: "Phone number should include the area code",
}Changing the input rune
In some situations, ? is a perfectly valid response. To handle this, you can change the rune that survey
looks for by setting the HelpInputRune variable in survey/core:
import (
"github.com/tj/survey"
surveyCore "github.com/tj/survey/core"
)
number := ""
prompt := &survey.Input{
Message: "If you have this need, please give me a reasonable message.",
Help: "I couldn't come up with one.",
}
surveyCore.HelpInputRune = '^'
survey.AskOne(prompt, &number, nil)Custom Types
survey will assign prompt answers to your custom types if they implement this interface:
type settable interface {
WriteAnswer(field string, value interface{}) error
}Here is an example how to use them:
type MyValue struct {
value string
}
func (my *MyValue) WriteAnswer(name string, value interface{}) error {
my.value = value.(string)
}
myval := MyValue{}
survey.AskOne(
&survey.Input{
Message: "Enter something:",
},
&myval,
nil,
)Customizing Output
Customizing the icons and various parts of survey can easily be done by setting the following variables
in survey/core:
| name | default | description |
|---|---|---|
| ErrorIcon | ✘ | Before an error |
| HelpIcon | ⓘ | Before help text |
| QuestionIcon | ? | Before the message of a prompt |
| SelectFocusIcon | ❯ | Marks the current focus in Select and MultiSelect prompts |
| MarkedOptionIcon | ◉ | Marks a chosen selection in a MultiSelect prompt |
| UnmarkedOptionIcon | ◯ | Marks an unselected option in a MultiSelect prompt |
Versioning
This project tries to maintain semantic GitHub releases as closely as possible. And relies on gopkg.in to maintain those releasees. Importing v1 of survey could look something like
package main
import "github.com/tj/survey"
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