add a new 'overview' MVC example

Former-commit-id: f73cbf6010595c639f6c5b5119e2ec41bc9802a5

_examples/mvc/repository/web/controllers/hello_controller.go

@@ -0,0 +1,58 @@
+// file: web/controllers/hello_controller.go
+
+package controllers
+
+import (
+	"errors"
+
+	"github.com/kataras/iris/v12/mvc"
+)
+
+// HelloController is our sample controller
+// it handles GET: /hello and GET: /hello/{name}
+type HelloController struct{}
+
+var helloView = mvc.View{
+	Name: "hello/index.html",
+	Data: map[string]interface{}{
+		"Title":     "Hello Page",
+		"MyMessage": "Welcome to my awesome website",
+	},
+}
+
+// Get will return a predefined view with bind data.
+//
+// `mvc.Result` is just an interface with a `Dispatch` function.
+// `mvc.Response` and `mvc.View` are the builtin result type dispatchers
+// you can even create custom response dispatchers by
+// implementing the `github.com/kataras/iris/hero#Result` interface.
+func (c *HelloController) Get() mvc.Result {
+	return helloView
+}
+
+// you can define a standard error in order to re-use anywhere in your app.
+var errBadName = errors.New("bad name")
+
+// you can just return it as error or even better
+// wrap this error with an mvc.Response to make it an mvc.Result compatible type.
+var badName = mvc.Response{Err: errBadName, Code: 400}
+
+// GetBy returns a "Hello {name}" response.
+// Demos:
+// curl -i http://localhost:8080/hello/iris
+// curl -i http://localhost:8080/hello/anything
+func (c *HelloController) GetBy(name string) mvc.Result {
+	if name != "iris" {
+		return badName
+		// or
+		// GetBy(name string) (mvc.Result, error) {
+		//	return nil, errBadName
+		// }
+	}
+
+	// return mvc.Response{Text: "Hello " + name} OR:
+	return mvc.View{
+		Name: "hello/name.html",
+		Data: name,
+	}
+}

_examples/mvc/repository/web/controllers/movie_controller.go

@@ -0,0 +1,77 @@
+// file: web/controllers/movie_controller.go
+
+package controllers
+
+import (
+	"errors"
+
+	"github.com/kataras/iris/v12/_examples/mvc/repository/datamodels"
+	"github.com/kataras/iris/v12/_examples/mvc/repository/services"
+
+	"github.com/kataras/iris/v12"
+)
+
+// MovieController is our /movies controller.
+type MovieController struct {
+	// Our MovieService, it's an interface which
+	// is binded from the main application.
+	Service services.MovieService
+}
+
+// Get returns list of the movies.
+// Demo:
+// curl -i http://localhost:8080/movies
+//
+// The correct way if you have sensitive data:
+// func (c *MovieController) Get() (results []viewmodels.Movie) {
+// 	data := c.Service.GetAll()
+//
+// 	for _, movie := range data {
+// 		results = append(results, viewmodels.Movie{movie})
+// 	}
+// 	return
+// }
+// otherwise just return the datamodels.
+func (c *MovieController) Get() (results []datamodels.Movie) {
+	return c.Service.GetAll()
+}
+
+// GetBy returns a movie.
+// Demo:
+// curl -i http://localhost:8080/movies/1
+func (c *MovieController) GetBy(id int64) (movie datamodels.Movie, found bool) {
+	return c.Service.GetByID(id) // it will throw 404 if not found.
+}
+
+// PutBy updates a movie.
+// Demo:
+// curl -i -X PUT -F "genre=Thriller" -F "poster=@/Users/kataras/Downloads/out.gif" http://localhost:8080/movies/1
+func (c *MovieController) PutBy(ctx iris.Context, id int64) (datamodels.Movie, error) {
+	// get the request data for poster and genre
+	file, info, err := ctx.FormFile("poster")
+	if err != nil {
+		return datamodels.Movie{}, errors.New("failed due form file 'poster' missing")
+	}
+	// we don't need the file so close it now.
+	file.Close()
+
+	// imagine that is the url of the uploaded file...
+	poster := info.Filename
+	genre := ctx.FormValue("genre")
+
+	return c.Service.UpdatePosterAndGenreByID(id, poster, genre)
+}
+
+// DeleteBy deletes a movie.
+// Demo:
+// curl -i -X DELETE -u admin:password http://localhost:8080/movies/1
+func (c *MovieController) DeleteBy(id int64) interface{} {
+	wasDel := c.Service.DeleteByID(id)
+	if wasDel {
+		// return the deleted movie's ID
+		return iris.Map{"deleted": id}
+	}
+	// right here we can see that a method function can return any of those two types(map or int),
+	// we don't have to specify the return type to a specific type.
+	return iris.StatusBadRequest
+}