Update sessions/sessiondb/badger to its latest version and SessionController is able to initialize itself if session manager is not provided by the caller-dev.

Changes:

Update the badger database using transactions, as supported from yesterday via: 06242925c2

Add a custom `OnActivate` via mvc/activator/activate_listener.go, this can be used to perform any custom actions when the app registers the supported Controllers. See mvc/session_controller.go for the excellent use case.

errors.Reporter.AddErr returns true if the error is added to the stack, otherwise false


Former-commit-id: c896a2d186a4315643f3c5fdb4325f7ee48a9e0a

mvc/activator/activate_listener.go

@@ -0,0 +1,78 @@
+package activator
+
+import (
+	"reflect"
+)
+
+// CallOnActivate simply calls the "controller"'s `OnActivate(*ActivatePayload)` function,
+// if any.
+//
+// Look `activator.go#Register` and `ActivateListener` for more.
+func CallOnActivate(controller interface{},
+	bindValues *[]interface{}, registerFunc RegisterFunc) {
+
+	if ac, ok := controller.(ActivateListener); ok {
+		p := &ActivatePayload{
+			BindValues: bindValues,
+			Handle:     registerFunc,
+		}
+		ac.OnActivate(p)
+	}
+}
+
+// ActivateListener is an interface which should be declared
+// on a Controller which needs to register or change the bind values
+// that the caller-"user" has been passed to; via the `app.Controller`.
+// If that interface is completed by a controller
+// then the `OnActivate` function will be called ONCE, NOT in every request
+// but ONCE at the application's lifecycle.
+type ActivateListener interface {
+	// OnActivate accepts a pointer to the `ActivatePayload`.
+	//
+	// The `Controller` can make use of the `OnActivate` function
+	// to register custom routes
+	// or modify the provided values that will be binded to the
+	// controller later on.
+	//
+	// Look `ActivatePayload` for more.
+	OnActivate(*ActivatePayload)
+}
+
+// ActivatePayload contains the necessary information and the ability
+// to alt a controller's registration options, i.e the binder.
+//
+// With `ActivatePayload` the `Controller` can register custom routes
+// or modify the provided values that will be binded to the
+// controller later on.
+type ActivatePayload struct {
+	BindValues *[]interface{}
+	Handle     RegisterFunc
+}
+
+// EnsureBindValue will make sure that this "bindValue"
+// will be registered to the controller's binder
+// if its type is not already passed by the caller..
+//
+// For example, on `SessionController` it looks if *sessions.Sessions
+// has been binded from the caller and if not then the "bindValue"
+// will be binded and used as a default sessions manager instead.
+//
+// At general, if the caller has already provided a value with the same Type
+// then the "bindValue" will be ignored and not be added to the controller's bind values.
+//
+// Returns true if the caller has NOT already provided a value with the same Type
+// and "bindValue" is NOT ignored therefore is appended to the controller's bind values.
+func (i *ActivatePayload) EnsureBindValue(bindValue interface{}) bool {
+	valueTyp := reflect.TypeOf(bindValue)
+	localBindValues := *i.BindValues
+
+	for _, bindedValue := range localBindValues {
+		// type already exists, remember: binding here is per-type.
+		if reflect.TypeOf(bindedValue) == valueTyp {
+			return false
+		}
+	}
+
+	*i.BindValues = append(localBindValues, bindValue)
+	return true
+}

mvc/activator/activator.go

@@ -65,7 +65,6 @@ type BaseController interface {
 
 // ActivateController returns a new controller type info description.
 func ActivateController(base BaseController, bindValues []interface{}) (TController, error) {
-
 	// get and save the type.
 	typ := reflect.TypeOf(base)
 	if typ.Kind() != reflect.Ptr {
@@ -202,6 +201,8 @@ func RegisterMethodHandlers(t TController, registerFunc RegisterFunc) {
 func Register(controller BaseController, bindValues []interface{},
 	registerFunc RegisterFunc) error {
 
+	CallOnActivate(controller, &bindValues, registerFunc)
+
 	t, err := ActivateController(controller, bindValues)
 	if err != nil {
 		return err