Add Context.SetUser and Context.User methods

relative to: https://github.com/iris-contrib/middleware/issues/63

context/context_user.go

@@ -0,0 +1,144 @@
+package context
+
+import (
+	"errors"
+	"time"
+)
+
+// ErrNotSupported is fired when a specific method is not implemented
+// or not supported entirely.
+// Can be used by User implementations when
+// an authentication system does not implement a specific, but required,
+// method of the User interface.
+var ErrNotSupported = errors.New("not supported")
+
+// User is a generic view of an authorized client.
+// See `Context.User` and `SetUser` methods for more.
+//
+// The informational methods starts with a "Get" prefix
+// in order to allow the implementation to contain exported
+// fields such as `Username` so they can be JSON encoded when necessary.
+//
+// The caller is free to cast this with the implementation directly
+// when special features are offered by the authorization system.
+type User interface {
+	// GetAuthorization should return the authorization method,
+	// e.g. Basic Authentication.
+	GetAuthorization() string
+	// GetAuthorizedAt should return the exact time the
+	// client has been authorized for the "first" time.
+	GetAuthorizedAt() time.Time
+	// GetUsername should return the name of the User.
+	GetUsername() string
+	// GetPassword should return the encoded or raw password
+	// (depends on the implementation) of the User.
+	GetPassword() string
+	// GetEmail should return the e-mail of the User.
+	GetEmail() string
+}
+
+// FeaturedUser optional interface that a User can implement.
+type FeaturedUser interface {
+	User
+	// GetFeatures should optionally return a list of features
+	// the User implementation offers.
+	GetFeatures() []UserFeature
+}
+
+// UserFeature a type which represents a user's optional feature.
+// See `HasUserFeature` function for more.
+type UserFeature uint32
+
+// The list of standard UserFeatures.
+const (
+	AuthorizedAtFeature UserFeature = iota
+	UsernameFeature
+	PasswordFeature
+	EmailFeature
+)
+
+// HasUserFeature reports whether the "u" User
+// implements a specific "feature" User Feature.
+//
+// It returns ErrNotSupported if a user does not implement
+// the FeaturedUser interface.
+func HasUserFeature(user User, feature UserFeature) (bool, error) {
+	if u, ok := user.(FeaturedUser); ok {
+		for _, f := range u.GetFeatures() {
+			if f == feature {
+				return true, nil
+			}
+		}
+
+		return false, nil
+	}
+
+	return false, ErrNotSupported
+}
+
+// SimpleUser is a simple implementation of the User interface.
+type SimpleUser struct {
+	Authorization string        `json:"authorization"`
+	AuthorizedAt  time.Time     `json:"authorized_at"`
+	Username      string        `json:"username"`
+	Password      string        `json:"-"`
+	Email         string        `json:"email,omitempty"`
+	Features      []UserFeature `json:"-"`
+}
+
+var _ User = (*SimpleUser)(nil)
+
+// GetAuthorization returns the authorization method,
+// e.g. Basic Authentication.
+func (u *SimpleUser) GetAuthorization() string {
+	return u.Authorization
+}
+
+// GetAuthorizedAt returns the exact time the
+// client has been authorized for the "first" time.
+func (u *SimpleUser) GetAuthorizedAt() time.Time {
+	return u.AuthorizedAt
+}
+
+// GetUsername returns the name of the User.
+func (u *SimpleUser) GetUsername() string {
+	return u.Username
+}
+
+// GetPassword returns the raw password of the User.
+func (u *SimpleUser) GetPassword() string {
+	return u.Password
+}
+
+// GetEmail returns the e-mail of the User.
+func (u *SimpleUser) GetEmail() string {
+	return u.Email
+}
+
+// GetFeatures returns a list of features
+// this User implementation offers.
+func (u *SimpleUser) GetFeatures() []UserFeature {
+	if u.Features != nil {
+		return u.Features
+	}
+
+	var features []UserFeature
+
+	if !u.AuthorizedAt.IsZero() {
+		features = append(features, AuthorizedAtFeature)
+	}
+
+	if u.Username != "" {
+		features = append(features, UsernameFeature)
+	}
+
+	if u.Password != "" {
+		features = append(features, PasswordFeature)
+	}
+
+	if u.Email != "" {
+		features = append(features, EmailFeature)
+	}
+
+	return features
+}