From 261ece56963f01ea655bbe90c03442bd4b8c91ab Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Sun, 26 Jan 2014 17:10:33 +0800
Subject: [PATCH] Make callback delete works

---
 callback_delete.go |  4 ++++
 callback_shared.go |  9 ++++++++
 gorm_test.go       |  1 -
 scope.go           | 55 +++++++++++++++++++++++++++++++++++++++++-----
 4 files changed, 63 insertions(+), 6 deletions(-)
 create mode 100644 callback_shared.go

diff --git a/callback_delete.go b/callback_delete.go
index 7b35bca4..9dc5b692 100644
--- a/callback_delete.go
+++ b/callback_delete.go
@@ -10,6 +10,8 @@ func BeforeDelete(scope *Scope) {
 }
 
 func Delete(scope *Scope) {
+	defer scope.Trace(time.Now())
+
 	if scope.HasError() {
 		return
 	}
@@ -33,7 +35,9 @@ func AfterDelete(scope *Scope) {
 }
 
 func init() {
+	DefaultCallback.Delete().Register("begin_transaction", BeginTransaction)
 	DefaultCallback.Delete().Register("before_delete", BeforeDelete)
 	DefaultCallback.Delete().Register("delete", Delete)
 	DefaultCallback.Delete().Register("after_delete", AfterDelete)
+	DefaultCallback.Delete().Register("commit_or_rollback_transaction", CommitOrRollbackTransaction)
 }
diff --git a/callback_shared.go b/callback_shared.go
new file mode 100644
index 00000000..3ff5f104
--- /dev/null
+++ b/callback_shared.go
@@ -0,0 +1,9 @@
+package gorm
+
+func BeginTransaction(scope *Scope) {
+	scope.Begin()
+}
+
+func CommitOrRollbackTransaction(scope *Scope) {
+	scope.CommitOrRollback()
+}
diff --git a/gorm_test.go b/gorm_test.go
index e3eba586..1a533d20 100644
--- a/gorm_test.go
+++ b/gorm_test.go
@@ -1504,7 +1504,6 @@ func TestTransaction(t *testing.T) {
 	if err := tx2.Save(&u2).Error; err != nil {
 		t.Errorf("No error should raise, but got", err)
 	}
-	tx2.Update("age", 90)
 
 	if err := tx2.First(&User{}, "name = ?", "transcation-2").Error; err != nil {
 		t.Errorf("Should find saved record, but got", err)
diff --git a/scope.go b/scope.go
index d72388c3..6d908cab 100644
--- a/scope.go
+++ b/scope.go
@@ -5,17 +5,19 @@ import (
 	"fmt"
 	"github.com/jinzhu/gorm/dialect"
 	"strings"
+	"time"
 
 	"reflect"
 	"regexp"
 )
 
 type Scope struct {
-	Value   interface{}
-	Search  *search
-	Sql     string
-	SqlVars []interface{}
-	db      *DB
+	Value              interface{}
+	Search             *search
+	Sql                string
+	SqlVars            []interface{}
+	db                 *DB
+	startedTransaction bool
 }
 
 func (db *DB) newScope(value interface{}) *Scope {
@@ -52,6 +54,21 @@ func (scope *Scope) PrimaryKey() string {
 	return "id"
 }
 
+func (scope *Scope) PrimaryKeyZero() bool {
+	return isBlank(reflect.ValueOf(scope.PrimaryKeyValue()))
+}
+
+func (scope *Scope) PrimaryKeyValue() interface{} {
+	data := reflect.Indirect(reflect.ValueOf(scope.Value))
+
+	if data.Kind() == reflect.Struct {
+		if field := data.FieldByName(snakeToUpperCamel(scope.PrimaryKey())); field.IsValid() {
+			return field.Interface()
+		}
+	}
+	return 0
+}
+
 func (scope *Scope) HasColumn(name string) bool {
 	data := reflect.Indirect(reflect.ValueOf(scope.Value))
 
@@ -146,3 +163,31 @@ func (scope *Scope) Exec() {
 		scope.Err(err)
 	}
 }
+
+func (scope *Scope) Trace(t time.Time) {
+	if len(scope.Sql) > 0 {
+		scope.db.slog(scope.Sql, t, scope.SqlVars...)
+	}
+}
+
+func (scope *Scope) Begin() *Scope {
+	if tx, err := scope.DB().(sqlDb).Begin(); err == nil {
+		scope.db.db = interface{}(tx).(sqlCommon)
+		scope.startedTransaction = true
+	}
+	return scope
+}
+
+func (scope *Scope) CommitOrRollback() *Scope {
+	if scope.startedTransaction {
+		if db, ok := scope.db.db.(sqlTx); ok {
+			if scope.HasError() {
+				db.Rollback()
+			} else {
+				db.Commit()
+			}
+			scope.db.db = scope.db.parent.db
+		}
+	}
+	return scope
+}