Update the _examples/mvc/login example - add a Path property at mvc.Response and add a context.Proceed helper function

Former-commit-id: b898901fe4a324e888a6e09c93530cf7a551cf2a

_examples/mvc/login/datasource/users.go

@@ -0,0 +1,31 @@
+// file: datasource/users.go
+
+package datasource
+
+import (
+	"errors"
+
+	"github.com/kataras/iris/_examples/mvc/login/datamodels"
+)
+
+// Engine is from where to fetch the data, in this case the users.
+type Engine uint32
+
+const (
+	// Memory stands for simple memory location;
+	// map[int64] datamodels.User ready to use, it's our source in this example.
+	Memory Engine = iota
+	// Bolt for boltdb source location.
+	Bolt
+	// MySQL for mysql-compatible source location.
+	MySQL
+)
+
+// LoadUsers returns all users(empty map) from the memory, for the shake of simplicty.
+func LoadUsers(engine Engine) (map[int64]datamodels.User, error) {
+	if engine != Memory {
+		return nil, errors.New("for the shake of simplicity we're using a simple map as the data source")
+	}
+
+	return make(map[int64]datamodels.User), nil
+}