reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/view/quicktemplate/controllers/hello.go

@@ -0,0 +1,30 @@
+package controllers
+
+import (
+	"github.com/kataras/iris/v12/_examples/response-writer/quicktemplate/templates"
+
+	"github.com/kataras/iris/v12"
+)
+
+// Hello renders our ../templates/hello.qtpl file using the compiled ../templates/hello.qtpl.go file.
+func Hello(ctx iris.Context) {
+	// vars := make(map[string]interface{})
+	// vars["message"] = "Hello World!"
+	// vars["name"] = ctx.Params().Get("name")
+	// [...]
+	// &templates.Hello{ Vars: vars }
+	// [...]
+
+	// However, as an alternative, we recommend that you should the `ctx.ViewData(key, value)`
+	// in order to be able modify the `templates.Hello#Vars` from a middleware(other handlers) as well.
+	ctx.ViewData("message", "Hello World!")
+	ctx.ViewData("name", ctx.Params().Get("name"))
+
+	// set view data to the `Vars` template's field
+	tmpl := &templates.Hello{
+		Vars: ctx.GetViewData(),
+	}
+
+	// render the template
+	ExecuteTemplate(ctx, tmpl)
+}