Enhance the MVC "using-method-result" example. Prev: update to version 8.5.0

Prev Commit: 49ee8f2d75 [formerly 6a3579f2500fc715d7dc606478960946dcade61d]

Changelog: https://github.com/kataras/iris/blob/master/HISTORY.md#mo-09-october-2017--v850

This example is updated with the current commit: https://github.com/kataras/iris/tree/master/_examples/mvc/using-output-result


Former-commit-id: 29486ef014b3667fa1c7c66e11c8e95c76a37e57

_examples/mvc/using-method-result/models/movie.go

@@ -2,10 +2,40 @@
 
 package models
 
+import "github.com/kataras/iris/context"
+
 // Movie is our sample data structure.
 type Movie struct {
+	ID     int64  `json:"id"`
 	Name   string `json:"name"`
 	Year   int    `json:"year"`
 	Genre  string `json:"genre"`
 	Poster string `json:"poster"`
 }
+
+// Dispatch completes the `kataras/iris/mvc#Result` interface.
+// Sends a `Movie` as a controlled http response.
+// If its ID is zero or less then it returns a 404 not found error
+// else it returns its json representation,
+// (just like the controller's functions do for custom types by default).
+//
+// Don't overdo it, the application's logic should not be here.
+// It's just one more step of validation before the response,
+// simple checks can be added here.
+//
+// It's just a showcase,
+// imagine what possible this opens when you designing a bigger application.
+//
+// This is called where the return value from a controller's method functions
+// is type of `Movie`.
+// For example the `controllers/movie_controller.go#GetBy`.
+func (m Movie) Dispatch(ctx context.Context) {
+	if m.ID <= 0 {
+		ctx.NotFound()
+		return
+	}
+	ctx.JSON(m, context.JSON{Indent: " "})
+}
+
+// For those who wonder `iris.Context`(go 1.9 type alias feature) and
+// `context.Context` is the same exact thing.