Added AfterCommit callbacks (#25)

Added AfterCommit callbacks

main.go

@@ -28,6 +28,8 @@ type DB struct {
 	callbacks     *Callback
 	dialect       Dialect
 	singularTable bool
+
+	afterCommitCallbacks []func(db *DB)
 }
 
 // Open initialize a new db connection, need to import driver first, e.g:
@@ -36,7 +38,9 @@ type DB struct {
 //	func main() {
 //	  db, err := gorm.Open("mysql", "user:password@/dbname?charset=utf8&parseTime=True&loc=Local")
 //	}
+//
 // GORM has wrapped some drivers, for easier to remember driver's import path, so you could import the mysql driver with
+//
 //	import _ "github.com/jinzhu/gorm/dialects/mysql"
 //	// import _ "github.com/jinzhu/gorm/dialects/postgres"
 //	// import _ "github.com/jinzhu/gorm/dialects/sqlite"
@@ -121,7 +125,9 @@ func (s *DB) Dialect() Dialect {
 }
 
 // Callback return `Callbacks` container, you could add/change/delete callbacks with it
+//
 //	db.Callback().Create().Register("update_created_at", updateCreated)
+//
 // Refer https://jinzhu.github.io/gorm/development.html#callbacks
 func (s *DB) Callback() *Callback {
 	s.parent.callbacks = s.parent.callbacks.clone()
@@ -224,6 +230,7 @@ func (s *DB) Offset(offset interface{}) *DB {
 }
 
 // Order specify order when retrieve records from database, set reorder to `true` to overwrite defined conditions
+//
 //	db.Order("name DESC")
 //	db.Order("name DESC", true) // reorder
 //	db.Order(gorm.Expr("name = ? DESC", "first")) // sql expression
@@ -253,12 +260,14 @@ func (s *DB) Having(query interface{}, values ...interface{}) *DB {
 }
 
 // Joins specify Joins conditions
+//
 //	db.Joins("JOIN emails ON emails.user_id = users.id AND emails.email = ?", "jinzhu@example.org").Find(&user)
 func (s *DB) Joins(query interface{}, args ...interface{}) *DB {
 	return s.clone().search.Joins(query, args...).db
 }
 
 // Scopes pass current database connection to arguments `func(*DB) *DB`, which could be used to add conditions dynamically
+//
 //	func AmountGreaterThan1000(db *gorm.DB) *gorm.DB {
 //	    return db.Where("amount > ?", 1000)
 //	}
@@ -270,6 +279,7 @@ func (s *DB) Joins(query interface{}, args ...interface{}) *DB {
 //	}
 //
 //	db.Scopes(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Find(&orders)
+//
 // Refer https://jinzhu.github.io/gorm/crud.html#scopes
 func (s *DB) Scopes(funcs ...func(*DB) *DB) *DB {
 	for _, f := range funcs {
@@ -356,6 +366,7 @@ func (s *DB) ScanRows(rows *sql.Rows, result interface{}) error {
 }
 
 // Pluck used to query single column from a model as a map
+//
 //	var ages []int64
 //	db.Find(&users).Pluck("age", &ages)
 func (s *DB) Pluck(column string, value interface{}) *DB {
@@ -454,6 +465,7 @@ func (s *DB) Delete(value interface{}, where ...interface{}) *DB {
 }
 
 // Raw use raw sql as conditions, won't run it unless invoked by other methods
+//
 //	db.Raw("SELECT name, age FROM users WHERE name = ?", 3).Scan(&result)
 func (s *DB) Raw(sql string, values ...interface{}) *DB {
 	return s.clone().search.Raw(true).Where(sql, values...).db
@@ -469,6 +481,7 @@ func (s *DB) Exec(sql string, values ...interface{}) *DB {
 }
 
 // Model specify the model you would like to run db operations
+//
 //	// update all users's name to `hello`
 //	db.Model(&User{}).Update("name", "hello")
 //	// if user's primary key is non-blank, will use it as condition, then will only update the user's name to `hello`
@@ -525,6 +538,16 @@ func (s *DB) Rollback() *DB {
 	return s
 }
 
+// AfterCommit invoke callback after transaction committed
+// If no transaction is currently running, it will be invoked immediately
+func (s *DB) AfterCommit(f func(db *DB)) {
+	if db, ok := s.db.(sqlTx); ok && db != nil {
+		s.afterCommitCallbacks = append(s.afterCommitCallbacks, f)
+	} else {
+		f(s)
+	}
+}
+
 // WrapInTx wraps a method in a transaction
 func (s *DB) WrapInTx(f func(tx *DB) error) (err error) {
 	if _, ok := s.db.(*sql.Tx); ok {
@@ -552,6 +575,11 @@ func (s *DB) WrapInTx(f func(tx *DB) error) (err error) {
 		err = f(tx)
 		if err == nil {
 			err = tx.Commit().Error
+			if err == nil {
+				for i := len(tx.afterCommitCallbacks) - 1; i >= 0; i-- {
+					tx.afterCommitCallbacks[i](s)
+				}
+			}
 		}
 		panicked = false
 		return
@@ -674,6 +702,7 @@ func (s *DB) RemoveIndex(indexName string) *DB {
 }
 
 // AddForeignKey Add foreign key to the given scope, e.g:
+//
 //	db.Model(&User{}).AddForeignKey("city_id", "cities(id)", "RESTRICT", "RESTRICT")
 func (s *DB) AddForeignKey(field string, dest string, onDelete string, onUpdate string) *DB {
 	scope := s.NewScope(s.Value)
@@ -682,6 +711,7 @@ func (s *DB) AddForeignKey(field string, dest string, onDelete string, onUpdate
 }
 
 // RemoveForeignKey Remove foreign key from the given scope, e.g:
+//
 //	db.Model(&User{}).RemoveForeignKey("city_id", "cities(id)")
 func (s *DB) RemoveForeignKey(field string, dest string) *DB {
 	scope := s.clone().NewScope(s.Value)
@@ -712,6 +742,7 @@ func (s *DB) Association(column string) *Association {
 }
 
 // Preload preload associations with given conditions
+//
 //	db.Preload("Orders", "state NOT IN (?)", "cancelled").Find(&users)
 func (s *DB) Preload(column string, conditions ...interface{}) *DB {
 	return s.clone().search.Preload(column, conditions...).db