New: i18n pluralization and variables support and more...

fixes: #1649, #1648, #1641, #1650

relative to: #1597

_examples/i18n/basic/locales/el-GR/locale_multi_first_el-GR.yml

@@ -0,0 +1 @@
+key1: "αυτό είναι μια τιμή από το πρώτο αρχείο: locale_multi_first"

_examples/i18n/basic/locales/en-US/locale_multi_first_en-US.yml

@@ -0,0 +1 @@
+key1: "this is a value from the first file: locale_multi_first"

_examples/i18n/i18n-template/locales/el-GR/welcome.yml

@@ -1,2 +0,0 @@
-Dog: "σκυλί"
-HiDogs: Γειά {{plural (tr "Dog") .count }}

_examples/i18n/i18n-template/locales/en-US/welcome.yml

@@ -1,2 +0,0 @@
-Dog: "dog"
-HiDogs: Hi {{plural (tr "Dog") .count }}

_examples/i18n/locales/el-GR/locale_multi_first_el-GR.ini

@@ -1 +0,0 @@
-key1 = αυτό είναι μια τιμή από το πρώτο αρχείο: locale_multi_first

_examples/i18n/locales/en-US/locale_multi_first_en-US.ini

@@ -1 +0,0 @@
-key1 = this is a value from the first file: locale_multi_first

_examples/i18n/plurals/locales/en-US/1648.ini

@@ -0,0 +1,5 @@
+[message]
+Encrypted = Encrypted
+Message = Message
+EncryptedMessage = {{tr "message.Encrypted"}} {{tr "message.Message"}}
+HostResult = Store {{tr "message.EncryptedMessage"}} Online

_examples/i18n/plurals/locales/en-US/welcome.yml

@@ -0,0 +1,89 @@
+# Locale variables
+#
+# Unlike normal keys, the variables
+# have limitations of: no ">x", "zero", "two" and template functions are supported.
+# This is done to force developers to use small and easy to read variables for easier maintain process. 
+Vars:
+  - Minutes:
+      # possible keys:
+      # one
+      # "=x"  - where x is a number
+      # "<x"
+      # other
+      # format - to customize the format, which defaults to %d .
+      one: "minute"
+      other: "minutes"
+      format: "%d" # defaults to that.
+  - Dogs:
+      "=5": "dogsssss"
+      one: "dog"
+      other: "dogs"
+  - Houses:
+      one: "house"
+      other: "houses"
+  - Gender:
+      "=1": "She" # 1 for female
+      "=2": "He" # 2 for male
+
+# Using variables in raw string
+YouLate: "You are %[1]d ${Minutes} late."
+# Just a simple raw value
+Classic: "classic"
+
+# Pluralization, translate based on the plural count
+# including the variables and their counts
+FreeDay:
+  # possible keys:
+  # zero
+  # one
+  # two
+  # "=x"
+  # "<x"
+  # ">x"
+  # other
+  "=3": "You have three days and %[2]d ${Minutes} off." # "FreeDay" 3, 15 (plurals + variable pluralization)
+  one:  "You have a day off" # "FreeDay", 1
+  other: "You have %[1]d free days" # "FreeDay", 5
+
+# Sprintf-like raw translation
+HeIsHome: "%s is home"
+
+# Value without plural of its self but variables except pluralization
+HouseCount: "${Gender} (%[3]s) has %[2]d ${Houses}"
+# Same as above but with a template instead
+VarTemplate: (${Gender}) {{tr "HeIsHome" .Name}}
+# Template and non template with variables in the same plural key
+VarTemplatePlural:
+  one: "${Gender} is awesome"
+  other: "other (${Gender}) has %[3]d ${Houses}"
+  "=5": "{{call .InlineJoin .Names}} are awesome"
+TemplatePlural:
+  one: "{{.Name}} is unique"
+  "=5": "{{call .InlineJoin .Names}} are awesome"
+# Same as above but it takes the variable counting through the map argument
+TemplateVarTemplatePlural:
+  other: "These {{.PluralCount}} are wonderful, feeding {{.DogsCount}} ${Dogs} in total!"
+
+# Local variables and section.
+LocalVarsHouseCount:
+   Text: "${Gender} has %[2]d ${Houses}"
+   Vars:
+    - Gender:
+        "=3": "She"
+        "=4": "He"
+    - Houses:
+        one: "house"
+        other: "houses"
+
+# Sections:
+root:
+  user: Account
+
+nav:
+  home: Home # nav.home
+  user: '{{tr "root.user"}}' # nav.user
+  more:
+    what: "this" # nav.more.what
+    even:
+      more: "yes" # nav.more.even.more
+      aplural: "You are %[1]d ${Minutes} late." # Tr("nav.more.even.aplural", 15)

_examples/i18n/plurals/main.go

@@ -0,0 +1,175 @@
+package main
+
+import (
+	"strings"
+
+	"github.com/kataras/iris/v12"
+)
+
+const (
+	female = iota + 1
+	male
+)
+
+const tableStyle = `
+<style>
+a {
+    padding: 8px 8px;
+    text-decoration:none;
+    cursor:pointer;
+    color: #10a2ff;
+}
+table {
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+    height: 100%;
+    width: 100%;
+    border-collapse: collapse;
+    border-spacing: 0;
+    empty-cells: show;
+    border: 1px solid #cbcbcb;
+}
+
+table caption {
+    color: #000;
+    font: italic 85%/1 arial, sans-serif;
+    padding: 1em 0;
+    text-align: center;
+}
+
+table td,
+table th {
+    border-left: 1px solid #cbcbcb;
+    border-width: 0 0 0 1px;
+    font-size: inherit;
+    margin: 0;
+    overflow: visible;
+    padding: 0.5em 1em;
+}
+
+table thead {
+    background-color: #10a2ff;
+    color: #fff;
+    text-align: left;
+    vertical-align: bottom;
+}
+
+table td {
+    background-color: transparent;
+}
+
+.table-odd td {
+    background-color: #f2f2f2;
+}
+
+.table-bordered td {
+    border-bottom: 1px solid #cbcbcb;
+}
+.table-bordered tbody > tr:last-child > td {
+    border-bottom-width: 0;
+}
+</style>
+`
+
+/*
+$ go run .
+Visit http://localhost:8080
+*/
+func main() {
+	app := iris.New()
+	err := app.I18n.Load("./locales/*/*", "en-US")
+	// ^ here we only use a single locale for the sake of the example,
+	// on a real app you can register as many languages as you want to support.
+	if err != nil {
+		panic(err)
+	}
+
+	app.Get("/", func(ctx iris.Context) {
+		ctx.HTML("<html><body>\n")
+		ctx.WriteString(tableStyle)
+		ctx.WriteString(`<table class="table-bordered table-odd">
+<thead>
+  <tr>
+    <th>Key</th>
+    <th>Translation</th>
+    <th>Arguments</th>
+  </tr>
+</thead><tbody>
+`)
+		defer ctx.WriteString("</tbody></table></body></html>")
+
+		tr(ctx, "Classic")
+
+		tr(ctx, "YouLate", 1)
+		tr(ctx, "YouLate", 2)
+
+		tr(ctx, "FreeDay", 1)
+		tr(ctx, "FreeDay", 5)
+
+		tr(ctx, "FreeDay", 3, 15)
+
+		tr(ctx, "HeIsHome", "Peter")
+
+		tr(ctx, "HouseCount", female, 2, "Maria")
+		tr(ctx, "HouseCount", male, 1, "Peter")
+
+		tr(ctx, "nav.home")
+		tr(ctx, "nav.user")
+		tr(ctx, "nav.more.what")
+		tr(ctx, "nav.more.even.more")
+		tr(ctx, "nav.more.even.aplural", 1)
+		tr(ctx, "nav.more.even.aplural", 15)
+
+		tr(ctx, "VarTemplate", iris.Map{
+			"Name":        "Peter",
+			"GenderCount": male,
+		})
+
+		tr(ctx, "VarTemplatePlural", 1, female)
+		tr(ctx, "VarTemplatePlural", 2, female, 1)
+		tr(ctx, "VarTemplatePlural", 2, female, 5)
+		tr(ctx, "VarTemplatePlural", 1, male)
+		tr(ctx, "VarTemplatePlural", 2, male, 1)
+		tr(ctx, "VarTemplatePlural", 2, male, 2)
+
+		tr(ctx, "VarTemplatePlural", iris.Map{
+			"PluralCount": 5,
+			"Names":       []string{"Makis", "Peter"},
+			"InlineJoin": func(arr []string) string {
+				return strings.Join(arr, ", ")
+			},
+		})
+
+		tr(ctx, "TemplatePlural", iris.Map{
+			"PluralCount": 1,
+			"Name":        "Peter",
+		})
+		tr(ctx, "TemplatePlural", iris.Map{
+			"PluralCount": 5,
+			"Names":       []string{"Makis", "Peter"},
+			"InlineJoin": func(arr []string) string {
+				return strings.Join(arr, ", ")
+			},
+		})
+		tr(ctx, "VarTemplatePlural", 2, male, 4)
+
+		tr(ctx, "TemplateVarTemplatePlural", iris.Map{
+			"PluralCount": 3,
+			"DogsCount":   5,
+		})
+
+		tr(ctx, "message.HostResult")
+
+		tr(ctx, "LocalVarsHouseCount.Text", 3, 4)
+	})
+
+	app.Listen(":8080")
+}
+
+func tr(ctx iris.Context, key string, args ...interface{}) {
+	translation := ctx.Tr(key, args...)
+	ctx.Writef("<tr><td>%s</td><td>%s</td><td>%v</td></tr>\n", key, translation, args)
+}

_examples/i18n/plurals/main_test.go

@@ -0,0 +1,131 @@
+package main_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/httptest"
+)
+
+const (
+	female = iota + 1
+	male
+)
+
+func TestI18nPlurals(t *testing.T) {
+	handler := func(ctx iris.Context) {
+		tr(ctx, "Classic")
+
+		tr(ctx, "YouLate", 1)
+		tr(ctx, "YouLate", 2)
+
+		tr(ctx, "FreeDay", 1)
+		tr(ctx, "FreeDay", 5)
+
+		tr(ctx, "FreeDay", 3, 15)
+
+		tr(ctx, "HeIsHome", "Peter")
+
+		tr(ctx, "HouseCount", female, 2, "Maria")
+		tr(ctx, "HouseCount", male, 1, "Peter")
+
+		tr(ctx, "nav.home")
+		tr(ctx, "nav.user")
+		tr(ctx, "nav.more.what")
+		tr(ctx, "nav.more.even.more")
+		tr(ctx, "nav.more.even.aplural", 1)
+		tr(ctx, "nav.more.even.aplural", 15)
+
+		tr(ctx, "VarTemplate", iris.Map{
+			"Name":        "Peter",
+			"GenderCount": male,
+		})
+
+		tr(ctx, "VarTemplatePlural", 1, female)
+		tr(ctx, "VarTemplatePlural", 2, female, 1)
+		tr(ctx, "VarTemplatePlural", 2, female, 5)
+		tr(ctx, "VarTemplatePlural", 1, male)
+		tr(ctx, "VarTemplatePlural", 2, male, 1)
+		tr(ctx, "VarTemplatePlural", 2, male, 2)
+
+		tr(ctx, "VarTemplatePlural", iris.Map{
+			"PluralCount": 5,
+			"Names":       []string{"Makis", "Peter"},
+			"InlineJoin": func(arr []string) string {
+				return strings.Join(arr, ", ")
+			},
+		})
+
+		tr(ctx, "TemplatePlural", iris.Map{
+			"PluralCount": 1,
+			"Name":        "Peter",
+		})
+		tr(ctx, "TemplatePlural", iris.Map{
+			"PluralCount": 5,
+			"Names":       []string{"Makis", "Peter"},
+			"InlineJoin": func(arr []string) string {
+				return strings.Join(arr, ", ")
+			},
+		})
+		tr(ctx, "VarTemplatePlural", 2, male, 4)
+
+		tr(ctx, "TemplateVarTemplatePlural", iris.Map{
+			"PluralCount": 3,
+			"DogsCount":   5,
+		})
+
+		tr(ctx, "message.HostResult")
+
+		tr(ctx, "LocalVarsHouseCount.Text", 3, 4)
+	}
+
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("GET", "/", nil)
+	defer r.Body.Close()
+	httptest.Do(w, r, handler, func(app *iris.Application) {
+		err := app.I18n.Load("./locales/*/*", "en-US", "el-GR")
+		if err != nil {
+			panic(err)
+		}
+	})
+
+	expected := `Classic=classic
+YouLate=You are 1 minute late.
+YouLate=You are 2 minutes late.
+FreeDay=You have a day off
+FreeDay=You have 5 free days
+FreeDay=You have three days and 15 minutes off.
+HeIsHome=Peter is home
+HouseCount=She (Maria) has 2 houses
+HouseCount=He (Peter) has 1 house
+nav.home=Home
+nav.user=Account
+nav.more.what=this
+nav.more.even.more=yes
+nav.more.even.aplural=You are 1 minute late.
+nav.more.even.aplural=You are 15 minutes late.
+VarTemplate=(He) Peter is home
+VarTemplatePlural=She is awesome
+VarTemplatePlural=other (She) has 1 house
+VarTemplatePlural=other (She) has 5 houses
+VarTemplatePlural=He is awesome
+VarTemplatePlural=other (He) has 1 house
+VarTemplatePlural=other (He) has 2 houses
+VarTemplatePlural=Makis, Peter are awesome
+TemplatePlural=Peter is unique
+TemplatePlural=Makis, Peter are awesome
+VarTemplatePlural=other (He) has 4 houses
+TemplateVarTemplatePlural=These 3 are wonderful, feeding 5 dogsssss in total!
+message.HostResult=Store Encrypted Message Online
+LocalVarsHouseCount.Text=She has 4 houses
+`
+	if got := w.Body.String(); expected != got {
+		t.Fatalf("expected:\n'%s'\n\nbut got:\n'%s'", expected, got)
+	}
+}
+
+func tr(ctx iris.Context, key string, args ...interface{}) {
+	translation := ctx.Tr(key, args...)
+	ctx.Writef("%s=%s\n", key, translation)
+}

_examples/i18n/template/locales/el-GR/welcome.yml

@@ -0,0 +1 @@
+HiDogs: Hi %d {{plural (tr "Dog") .count }}

_examples/i18n/template/locales/en-US/welcome.yml

@@ -0,0 +1,2 @@
+Dog: "dog"
+HiDogs: Hi %d {{plural (tr "Dog") .count }}

_examples/i18n/template/main.go

@@ -5,13 +5,20 @@ import (
 	"text/template"
 
 	"github.com/kataras/iris/v12"
-	// go get -u github.com/gertd/go-pluralize
-	"github.com/gertd/go-pluralize"
+
+	// go get -u golang.org/x/text/message
+
+	"golang.org/x/text/feature/plural"
+	"golang.org/x/text/language"
+	"golang.org/x/text/message"
 )
 
 /*
  Iris I18n supports text/template inside the translation values.
  Follow this example to learn how to use that feature.
+
+ This is just an example on how to use template functions.
+ See the "plurals" example for a more comprehensive pluralization support instead.
 */
 
 func main() {
@@ -22,7 +29,20 @@ func main() {
 func newApp() *iris.Application {
 	app := iris.New()
 
-	pluralize := pluralize.NewClient()
+	// set the printers after load, so they can be done by loop of available languages.
+	printers := make(map[string]*message.Printer)
+
+	message.Set(language.Greek, "Hello %d dog",
+		plural.Selectf(1, "%d",
+			"one", "Γεια σου σκυλί",
+			"other", "Γεια σας %[1]d σκυλιά",
+		))
+
+	/* by variable, single word:
+	message.Set(language.Greek, "Hi %d dog(s)",
+		catalog.Var("dogs", plural.Selectf(1, "%d", "one", "σκυλί", "other", "σκυλιά")),
+		catalog.String("Γεια %[1]d ${dogs}"))
+	*/
 
 	// Set custom functions per locale!
 	app.I18n.Loader.Funcs = func(current iris.Locale) template.FuncMap {
@@ -30,12 +50,7 @@ func newApp() *iris.Application {
 			"plural": func(word string, count int) string {
 				// Your own implementation or use a 3rd-party package
 				// like we do here.
-				//
-				// Note that this is only for english,
-				// but you can use the "current" locale
-				// and make a map with dictionaries to
-				// pluralize words based on the given language.
-				return pluralize.Pluralize(word, count, true)
+				return printers[current.Language()].Sprintf(word, count)
 			},
 			"uppercase": func(word string) string {
 				return strings.ToUpper(word)
@@ -51,6 +66,12 @@ func newApp() *iris.Application {
 		panic(err)
 	}
 
+	for _, tag := range app.I18n.Tags() {
+		printers[tag.String()] = message.NewPrinter(tag)
+	}
+
+	message.NewPrinter(language.Greek).Printf("Hello %d dog", 2)
+
 	app.Get("/", func(ctx iris.Context) {
 		text := ctx.Tr("HiDogs", iris.Map{
 			"count": 2,