add some MVC error handle examples

2025-12-21 11:57:02 +00:00 · 2020-08-18 23:14:11 +03:00
parent 35ab1de212
commit 4228dd8ea4
14 changed files with 324 additions and 3 deletions
--- a/_examples/mvc/error-handler-custom-result/main.go
+++ b/_examples/mvc/error-handler-custom-result/main.go
@@ -0,0 +1,75 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/mvc"
+)
+
+func main() {
+	app := iris.New()
+	app.RegisterView(iris.HTML("./views", ".html"))
+
+	m := mvc.New(app)
+	m.Handle(new(controller))
+
+	app.Listen(":8080")
+}
+
+type errorResponse struct {
+	Code    int
+	Message string
+}
+
+/*
+// Note: if a struct implements the standard go error, so it's an error
+// and its Error() is not empty, then its text will be rendered instead,
+// override any Dispatch method.
+func (e errorResponse) Error() string {
+	return e.Message
+}
+*/
+
+// implements mvc.Result.
+func (e errorResponse) Dispatch(ctx iris.Context) {
+	// If u want to use mvc.Result on any method without an output return value
+	// go for it:
+	//
+	view := mvc.View{Code: e.Code, Data: e} // use Code and Message as the template data.
+	switch e.Code {
+	case iris.StatusNotFound:
+		view.Name = "404"
+	default:
+		view.Name = "500"
+	}
+	view.Dispatch(ctx)
+
+	// Otherwise use ctx methods:
+	//
+	// ctx.StatusCode(e.Code)
+	// switch e.Code {
+	// case iris.StatusNotFound:
+	// 	// use Code and Message as the template data.
+	// 	ctx.View("404.html", e)
+	// default:
+	// 	ctx.View("500.html", e)
+	// }
+}
+
+type controller struct{}
+
+type user struct {
+	ID uint64 `json:"id"`
+}
+
+func (c *controller) GetBy(userid uint64) mvc.Result {
+	if userid != 1 {
+		return errorResponse{
+			Code:    iris.StatusNotFound,
+			Message: "User Not Found",
+		}
+	}
+
+	return mvc.Response{
+		Object: user{ID: userid},
+	}
+}
--- a/_examples/mvc/error-handler-custom-result/views/404.html
+++ b/_examples/mvc/error-handler-custom-result/views/404.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Client Error Page</title>
+</head>
+<body>
+    <h2>{{.Code}}</h2>
+    <h3>{{.Message}}</h3>
+</body>
+</html>
--- a/_examples/mvc/error-handler-custom-result/views/500.html
+++ b/_examples/mvc/error-handler-custom-result/views/500.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Server Error Page</title>
+</head>
+<body>
+    <h2>{{.Code}}</h2>
+    <h3>{{.Message}}</h3>
+</body>
+</html>
--- a/_examples/mvc/error-handler-hijack/main.go
+++ b/_examples/mvc/error-handler-hijack/main.go
@@ -0,0 +1,60 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/mvc"
+)
+
+func main() {
+	app := iris.New()
+	app.RegisterView(iris.HTML("./views", ".html"))
+
+	// Hijack each output value of a method (can be used per-party too).
+	app.ConfigureContainer().
+		UseResultHandler(func(next iris.ResultHandler) iris.ResultHandler {
+			return func(ctx iris.Context, v interface{}) error {
+				switch val := v.(type) {
+				case errorResponse:
+					return next(ctx, errorView(val))
+				default:
+					return next(ctx, v)
+				}
+			}
+		})
+
+	m := mvc.New(app)
+	m.Handle(new(controller))
+
+	app.Listen(":8080")
+}
+
+func errorView(e errorResponse) mvc.Result {
+	switch e.Code {
+	case iris.StatusNotFound:
+		return mvc.View{Code: e.Code, Name: "404.html", Data: e}
+	default:
+		return mvc.View{Code: e.Code, Name: "500.html", Data: e}
+	}
+}
+
+type errorResponse struct {
+	Code    int
+	Message string
+}
+
+type controller struct{}
+
+type user struct {
+	ID uint64 `json:"id"`
+}
+
+func (c *controller) GetBy(userid uint64) interface{} {
+	if userid != 1 {
+		return errorResponse{
+			Code:    iris.StatusNotFound,
+			Message: "User Not Found",
+		}
+	}
+
+	return user{ID: userid}
+}
--- a/_examples/mvc/error-handler-hijack/views/404.html
+++ b/_examples/mvc/error-handler-hijack/views/404.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Client Error Page</title>
+</head>
+<body>
+    <h2>{{.Code}}</h2>
+    <h3>{{.Message}}</h3>
+</body>
+</html>
--- a/_examples/mvc/error-handler-hijack/views/500.html
+++ b/_examples/mvc/error-handler-hijack/views/500.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Server Error Page</title>
+</head>
+<body>
+    <h2>{{.Code}}</h2>
+    <h3>{{.Message}}</h3>
+</body>
+</html>
--- a/_examples/mvc/error-handler-preflight/main.go
+++ b/_examples/mvc/error-handler-preflight/main.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/mvc"
+)
+
+func main() {
+	app := iris.New()
+	app.RegisterView(iris.HTML("./views", ".html"))
+
+	m := mvc.New(app)
+	m.Handle(new(controller))
+
+	app.Listen(":8080")
+}
+
+type controller struct{}
+
+// Generic response type for JSON results.
+type response struct {
+	ID        uint64      `json:"id,omitempty"`
+	Data      interface{} `json:"data,omitempty"` // {data: result } on fetch actions.
+	Code      int         `json:"code,omitempty"`
+	Message   string      `json:"message,omitempty"`
+	Timestamp int64       `json:"timestamp,omitempty"`
+}
+
+func (r response) Preflight(ctx iris.Context) error {
+	if r.ID > 0 {
+		r.Timestamp = time.Now().Unix()
+	}
+
+	if code := r.Code; code > 0 {
+		// You can call ctx.View or mvc.Vew{...}.Dispatch
+		// to render HTML on Code != 200
+		// but in order to not proceed with the response resulting
+		// as JSON you MUST return the iris.ErrStopExecution error.
+		// Example:
+		if code != 200 {
+			mvc.View{
+				/* calls the ctx.StatusCode */
+				Code: code,
+				/* use any r.Data as the template data
+				OR the whole "response" as its data. */
+				Data: r,
+				/* automatically pick the template per error (just for the sake of the example) */
+				Name: fmt.Sprintf("%d", code),
+			}.Dispatch(ctx)
+
+			return iris.ErrStopExecution
+		}
+
+		ctx.StatusCode(r.Code)
+	}
+
+	return nil
+}
+
+type user struct {
+	ID uint64 `json:"id"`
+}
+
+func (c *controller) GetBy(userid uint64) response {
+	if userid != 1 {
+		return response{
+			Code:    iris.StatusNotFound,
+			Message: "User Not Found",
+		}
+	}
+
+	return response{
+		ID:   userid,
+		Data: user{ID: userid},
+	}
+}
+
+/*
+
+You can use that `response` structure on non-mvc applications too, using handlers:
+
+c := app.ConfigureContainer()
+c.Get("/{id:uint64}", getUserByID)
+func getUserByID(id uint64) response {
+	if userid != 1 {
+		return response{
+			Code:    iris.StatusNotFound,
+			Message: "User Not Found",
+		}
+	}
+
+	return response{
+		ID:   userid,
+		Data: user{ID: userid},
+	}
+}
+
+*/
--- a/_examples/mvc/error-handler-preflight/views/404.html
+++ b/_examples/mvc/error-handler-preflight/views/404.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Client Error Page</title>
+</head>
+<body>
+    <h2>{{.Code}}</h2>
+    <h3>{{.Message}}</h3>
+</body>
+</html>
--- a/_examples/mvc/error-handler-preflight/views/500.html
+++ b/_examples/mvc/error-handler-preflight/views/500.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Server Error Page</title>
+</head>
+<body>
+    <h2>{{.Code}}</h2>
+    <h3>{{.Message}}</h3>
+</body>
+</html>