Golang DB.NewScope方法代码示例

func move(db *gorm.DB, value sortingInterface, pos int) error {
	clone := db
	for _, field := range db.NewScope(value).PrimaryFields() {
		if field.DBName != "id" {
			clone = clone.Where(fmt.Sprintf("%s = ?", field.DBName), field.Field.Interface())
		}
	}

	currentPos := value.GetPosition()

	if pos > 0 {
		if results := clone.Model(newModel(value)).
			Where("position > ? AND position <= ?", currentPos, currentPos+pos).
			UpdateColumn("position", gorm.Expr("position - ?", 1)); results.Error == nil {
			value.SetPosition(currentPos + int(results.RowsAffected))
			return clone.Model(value).UpdateColumn("position", gorm.Expr("position + ?", results.RowsAffected)).Error
		}
	} else if pos < 0 {
		if results := clone.Model(newModel(value)).
			Where("position < ? AND position >= ?", currentPos, currentPos+pos).
			UpdateColumn("position", gorm.Expr("position + ?", 1)); results.Error == nil {
			value.SetPosition(currentPos - int(results.RowsAffected))
			return clone.Model(value).UpdateColumn("position", gorm.Expr("position - ?", results.RowsAffected)).Error
		}
	}
	return nil
}

func New(db *gorm.DB) *Publish {
	tableHandler := gorm.DefaultTableNameHandler
	gorm.DefaultTableNameHandler = func(db *gorm.DB, defaultTableName string) string {
		tableName := tableHandler(db, defaultTableName)

		if db != nil {
			if IsPublishableModel(db.Value) {
				// Set join table handler
				typ := utils.ModelType(db.Value)
				if !injectedJoinTableHandler[typ] {
					injectedJoinTableHandler[typ] = true
					scope := db.NewScope(db.Value)
					for _, field := range scope.GetModelStruct().StructFields {
						if many2many := utils.ParseTagOption(field.Tag.Get("gorm"))["MANY2MANY"]; many2many != "" {
							db.SetJoinTableHandler(db.Value, field.Name, &publishJoinTableHandler{})
							db.AutoMigrate(db.Value)
						}
					}
				}

				var forceDraftTable bool
				if forceDraftTable, ok := db.Get("publish:force_draft_table"); ok {
					if forceMode, ok := forceDraftTable.(bool); ok && forceMode {
						forceDraftTable = true
					}
				}

				if IsDraftMode(db) || forceDraftTable {
					return DraftTableName(tableName)
				}
			}
		}
		return tableName
	}

	db.AutoMigrate(&PublishEvent{})

	db.Callback().Create().Before("gorm:begin_transaction").Register("publish:set_table_to_draft", setTableAndPublishStatus(true))
	db.Callback().Create().Before("gorm:commit_or_rollback_transaction").
		Register("publish:sync_to_production_after_create", syncCreateFromProductionToDraft)
	db.Callback().Create().Before("gorm:commit_or_rollback_transaction").Register("gorm:create_publish_event", createPublishEvent)

	db.Callback().Delete().Before("gorm:begin_transaction").Register("publish:set_table_to_draft", setTableAndPublishStatus(true))
	db.Callback().Delete().Replace("gorm:delete", deleteScope)
	db.Callback().Delete().Before("gorm:commit_or_rollback_transaction").
		Register("publish:sync_to_production_after_delete", syncDeleteFromProductionToDraft)
	db.Callback().Delete().Before("gorm:commit_or_rollback_transaction").Register("gorm:create_publish_event", createPublishEvent)

	db.Callback().Update().Before("gorm:begin_transaction").Register("publish:set_table_to_draft", setTableAndPublishStatus(true))
	db.Callback().Update().Before("gorm:commit_or_rollback_transaction").
		Register("publish:sync_to_production", syncUpdateFromProductionToDraft)
	db.Callback().Update().Before("gorm:commit_or_rollback_transaction").Register("gorm:create_publish_event", createPublishEvent)

	db.Callback().RowQuery().Register("publish:set_table_in_draft_mode", setTableAndPublishStatus(false))
	db.Callback().Query().Before("gorm:query").Register("publish:set_table_in_draft_mode", setTableAndPublishStatus(false))
	return &Publish{DB: db}
}

func AddErrorForColumn(db *gorm.DB, resource interface{}, column, err string) {
	var validationErrors = GetErrors(db)
	var scope = db.NewScope(resource)

	key := fmt.Sprintf("%v_%v_%v", scope.GetModelStruct().ModelType.Name(), scope.PrimaryKeyValue(), column)
	validationErrors[key] = append(validationErrors[key], err)

	db.InstantSet(settingKey, validationErrors).Error = fmt.Errorf("RecordInvalid: %v", err)
}

func (*PersonAddress) Add(handler gorm.JoinTableHandlerInterface, db *gorm.DB, foreignValue interface{}, associationValue interface{}) error {
	return db.Where(map[string]interface{}{
		"person_id":  db.NewScope(foreignValue).PrimaryKeyValue(),
		"address_id": db.NewScope(associationValue).PrimaryKeyValue(),
	}).Assign(map[string]interface{}{
		"person_id":  foreignValue,
		"address_id": associationValue,
		"deleted_at": gorm.Expr("NULL"),
	}).FirstOrCreate(&PersonAddress{}).Error
}

// GetChangeLogs get state change logs
func GetStateChangeLogs(model interface{}, db *gorm.DB) []StateChangeLog {
	var (
		changelogs []StateChangeLog
		scope      = db.NewScope(model)
	)

	db.Where("refer_table = ? AND refer_id = ?", scope.TableName(), GenerateReferenceKey(model, db)).Find(&changelogs)

	return changelogs
}

// GenerateReferenceKey generate reference key used for change log
func GenerateReferenceKey(model interface{}, db *gorm.DB) string {
	var (
		scope         = db.NewScope(model)
		primaryValues []string
	)

	for _, field := range scope.PrimaryFields() {
		primaryValues = append(primaryValues, fmt.Sprint(field.Field.Interface()))
	}

	return strings.Join(primaryValues, "::")
}

func getCurrentUser(db *gorm.DB) (string, bool) {
	if user, hasUser := db.Get("qor:current_user"); hasUser {
		var currentUser string
		if primaryField := db.NewScope(user).PrimaryField(); primaryField != nil {
			currentUser = fmt.Sprintf("%v", primaryField.Field.Interface())
		} else {
			currentUser = fmt.Sprintf("%v", user)
		}

		return currentUser, true
	}

	return "", false
}

func move(db *gorm.DB, value sortingInterface, pos int) (err error) {
	var startedTransaction bool
	var tx = db.Set("publish:publish_event", true)
	if t := tx.Begin(); t.Error == nil {
		startedTransaction = true
		tx = t
	}

	scope := db.NewScope(value)
	for _, field := range scope.PrimaryFields() {
		if field.DBName != "id" {
			tx = tx.Where(fmt.Sprintf("%s = ?", field.DBName), field.Field.Interface())
		}
	}

	currentPos := value.GetPosition()

	var results *gorm.DB
	if pos > 0 {
		results = tx.Model(newModel(value)).
			Where("position > ? AND position <= ?", currentPos, currentPos+pos).
			UpdateColumn("position", gorm.Expr("position - ?", 1))
	} else {
		results = tx.Model(newModel(value)).
			Where("position < ? AND position >= ?", currentPos, currentPos+pos).
			UpdateColumn("position", gorm.Expr("position + ?", 1))
	}

	if err = results.Error; err == nil {
		var rowsAffected = int(results.RowsAffected)
		if pos < 0 {
			rowsAffected = -rowsAffected
		}
		value.SetPosition(currentPos + rowsAffected)
		err = tx.Model(value).UpdateColumn("position", gorm.Expr("position + ?", rowsAffected)).Error
	}

	// Create Publish Event
	createPublishEvent(tx, value)

	if startedTransaction {
		if err == nil {
			tx.Commit()
		} else {
			tx.Rollback()
		}
	}
	return err
}

func (e changedSortingPublishEvent) Discard(db *gorm.DB, event publish.PublishEventInterface) error {
	if event, ok := event.(*publish.PublishEvent); ok {
		scope := db.NewScope("")
		if err := json.Unmarshal([]byte(event.Argument), &e); err == nil {
			var conditions []string
			originalTable := scope.Quote(publish.OriginalTableName(e.Table))
			draftTable := scope.Quote(publish.DraftTableName(e.Table))
			for _, primaryKey := range e.PrimaryKeys {
				conditions = append(conditions, fmt.Sprintf("%v.%v = %v.%v", originalTable, primaryKey, draftTable, primaryKey))
			}
			sql := fmt.Sprintf("UPDATE %v SET position = (select position FROM %v WHERE %v);", draftTable, originalTable, strings.Join(conditions, " AND "))
			return db.Exec(sql).Error
		} else {
			return err
		}
	}
	return errors.New("invalid publish event")
}

func (pb Publish) search(db *gorm.DB, res *admin.Resource, ids [][]string) *gorm.DB {
	var primaryKeys []string
	var primaryValues [][][]interface{}
	var scope = db.NewScope(res.Value)

	for _, primaryField := range scope.PrimaryFields() {
		primaryKeys = append(primaryKeys, primaryField.DBName)
	}

	for _, id := range ids {
		var primaryValue [][]interface{}
		for idx, value := range id {
			primaryValue = append(primaryValue, []interface{}{primaryKeys[idx], value})
		}
		primaryValues = append(primaryValues, primaryValue)
	}

	sql := fmt.Sprintf("%v IN (%v)", toQueryCondition(scope, primaryKeys), toQueryMarks(primaryValues))
	return pb.SearchHandler(db, nil).Where(sql, toQueryValues(primaryValues)...)
}

func createPublishEvent(db *gorm.DB, value interface{}) (err error) {
	// Create Publish Event in Draft Mode
	if publish.IsDraftMode(db) && publish.IsPublishableModel(value) {
		scope := db.NewScope(value)
		var sortingPublishEvent = changedSortingPublishEvent{
			Table: scope.TableName(),
		}
		for _, field := range scope.PrimaryFields() {
			sortingPublishEvent.PrimaryKeys = append(sortingPublishEvent.PrimaryKeys, field.DBName)
		}

		var result []byte
		if result, err = json.Marshal(sortingPublishEvent); err == nil {
			err = db.New().Where("publish_status = ?", publish.DIRTY).Where(map[string]interface{}{
				"name":     "changed_sorting",
				"argument": string(result),
			}).Attrs(map[string]interface{}{
				"publish_status": publish.DIRTY,
				"description":    "Changed sort order for " + scope.GetModelStruct().ModelType.Name(),
			}).FirstOrCreate(&publish.PublishEvent{}).Error
		}
	}
	return
}

// Trigger trigger an event
func (sm *StateMachine) Trigger(name string, value Stater, tx *gorm.DB, notes ...string) error {
	var (
		newTx    *gorm.DB
		stateWas = value.GetState()
	)

	if tx != nil {
		newTx = tx.New()
	}

	if stateWas == "" {
		stateWas = sm.initialState
		value.SetState(sm.initialState)
	}

	if event := sm.events[name]; event != nil {
		var matchedTransitions []*EventTransition
		for _, transition := range event.transitions {
			var validFrom = len(transition.froms) == 0
			if len(transition.froms) > 0 {
				for _, from := range transition.froms {
					if from == stateWas {
						validFrom = true
					}
				}
			}

			if validFrom {
				matchedTransitions = append(matchedTransitions, transition)
			}
		}

		if len(matchedTransitions) == 1 {
			transition := matchedTransitions[0]

			// State: exit
			if state, ok := sm.states[stateWas]; ok {
				for _, exit := range state.exits {
					if err := exit(value, newTx); err != nil {
						return err
					}
				}
			}

			// Transition: before
			for _, before := range transition.befores {
				if err := before(value, newTx); err != nil {
					return err
				}
			}

			value.SetState(transition.to)

			// State: enter
			if state, ok := sm.states[transition.to]; ok {
				for _, enter := range state.enters {
					if err := enter(value, newTx); err != nil {
						value.SetState(stateWas)
						return err
					}
				}
			}

			// Transition: after
			for _, after := range transition.afters {
				if err := after(value, newTx); err != nil {
					value.SetState(stateWas)
					return err
				}
			}

			if newTx != nil {
				scope := newTx.NewScope(value)
				log := StateChangeLog{
					ReferTable: scope.TableName(),
					ReferID:    GenerateReferenceKey(value, tx),
					From:       stateWas,
					To:         transition.to,
					Note:       strings.Join(notes, ""),
				}
				return newTx.Save(&log).Error
			}

			return nil
		}
	}
	return fmt.Errorf("failed to perform event %s from state %s", name, stateWas)
}