examples: add an example for #2019

_examples/view/overview/main.go

@@ -1,6 +1,17 @@
 package main
 
-import "github.com/kataras/iris/v12"
+import (
+	"html/template"
+	"time"
+
+	"github.com/kataras/iris/v12"
+)
+
+// ViewFunctions presents some builtin functions
+// for html view engines. See `View.Funcs` or `view/html.Funcs` and etc.
+var Functions = template.FuncMap{
+	"Now": time.Now,
+}
 
 func main() {
 	app := iris.New()
@@ -13,7 +24,8 @@ func main() {
 	// - {{ yield . }}
 	// - {{ current . }}
 	app.RegisterView(iris.HTML("./templates", ".html").
-		Reload(true)) // Set Reload false to production.
+		Funcs(Functions). // Optionally register some more builtin functions.
+		Reload(false))    // Set Reload to true on development.
 
 	app.Get("/", func(ctx iris.Context) {
 		// enable compression based on Accept-Encoding (e.g. "gzip"),
@@ -30,13 +42,15 @@ func main() {
 	})
 
 	app.Get("/example_map", func(ctx iris.Context) {
-		if err := ctx.View("example.html", iris.Map{
+		examplePage := iris.Map{
 			"Name":   "Example Name",
 			"Age":    42,
 			"Items":  []string{"Example slice entry 1", "entry 2", "entry 3"},
 			"Map":    iris.Map{"map key": "map value", "other key": "other value"},
 			"Nested": iris.Map{"Title": "Iris E-Book", "Pages": 620},
-		}); err != nil {
+		}
+
+		if err := ctx.View("example.html", examplePage); err != nil {
 			ctx.HTML("<h3>%s</h3>", err.Error())
 			return
 		}
@@ -71,6 +85,23 @@ func main() {
 		}
 	})
 
+	app.Get("/functions", func(ctx iris.Context) {
+		var functionsPage = struct {
+			// A function.
+			Now func() time.Time
+			// A struct field which contains methods.
+			Ctx iris.Context
+		}{
+			Now: time.Now,
+			Ctx: ctx,
+		}
+
+		if err := ctx.View("functions.html", functionsPage); err != nil {
+			ctx.HTML("<h3>%s</h3>", err.Error())
+			return
+		}
+	})
+
 	// http://localhost:8080/
 	app.Listen(":8080")
 }

_examples/view/overview/templates/functions.html

@@ -0,0 +1,3 @@
+<h1>Function: {{ Now }}</h1>
+<h1>Field: {{ .Ctx.Request.URL.Path }} </h1>
+<h1>Field Struct's Function (Method): {{ .Ctx.FullRequestURI }} </h1>