The *i18n.Localizer returned by the bot.SettingsProvider we created on the previous page is now available in the *plugin.Context.
Using the Localizer
Localized text is generated using *i18n.Configs. Usually, these are placed in a terms.go file in your package. If you have many configs, it might also be advisable to group terms into foo_terms.go, bar_terms.go etc.
In your command's Invoke method, you can then use those *i18n.Configs to generate messages.
plugins/sum/terms.go
package sum
import "github.com/mavolin/adam/pkg/i18n"
var (
shortDescription = i18n.NewFallbackConfig(
"plugin.sum.short_description", "Add numbers together")
argsNumbersName = i18n.NewFallbackConfig(
"plugin.sum.args.numbers.name", "Numbers")
argsNumbersDescription = i18n.NewFallbackConfig(
"plugin.sum.arg.numbers.description",
"The numbers that shall be added.")
)
var (
errorNotEnoughNumbers = i18n.NewFallbackConfig(
"plugin.sum.error.not_enough_numbers", // term
"I need at least 2 numbers to calculate a sum!") // fallback
result = i18n.NewFallbackConfig(
"plugin.sum.result", "The sum is {{.sum}}.")
)
// The recommended way to fill placeholders is by using data structs.
// All exported fields will by put into snake_case and given to the Localizer
// as placeholders.
// If you want to use custom names, use the `i18n:"my_custom_name"` struct tag.
type resultPlaceholders struct {
Sum int
}
plugins/sum/sum.go
package sum
import (
"github.com/mavolin/adam/pkg/i18n"
"github.com/mavolin/adam/pkg/impl/arg"
)
type Sum struct {
command.Meta
}
func New() *Sum {
return &Sum{
Meta: command.LocalizedMeta{
Name: "sum",
ShortDescription: shortDescription,
Args: &arg.LocalizedConfig{
RequiredArgs: []arg.LocalizedRequiredArg{
{
Name: argsNumbersName,
Type: arg.Integer,
Description: argsNumbersDescription,
},
},
Variadic: true,
},
},
}
}
func (s *Say) (_ *state.State, ctx *plugin.Context) (interface{}, error) {
nums := ctx.Args.Ints(0)
if len(nums) >= 1 {
return nil, errors.NewUserErrorl(errorNotEnoughNumbers)
}
var sum int
for _, num := range nums {
sum += num
}
return result.WithPlaceholders(resultPlaceholders{
Sum: sum,
}, nil
}
Working with Localizers
As you might have already noticed, there are a lot of utilities for working with localized text. Structs typically come in two versions X and LocalizedX to provide localization support. If they are constructor-based, they might also use constructors like NewX, NewXl, and NewXlt where NewX creates an unlocalized version, NexXl uses a *i18n.Config, and NewXlt uses a i18n.Term.
The same also applies to other functions. For example plugin.Context provides Reply, Replyl and Replylt.