Cunning <mybatis:scan/> elemnt

In version 1.2.0 of Mybatis-Spring a possibility of scanning mapper interfaces via XML element <mybatis:scan/> has appeared. As a doc says  the <mybatis:scan/> XML element will search for mappers in a very similar way than the Spring built-in element <context:component-scan/>searches for beans. Here is an example:

<beans xmlns="http://www.springframework.org/schema/beans" 
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
       xmlns:mybatis="http://mybatis.org/schema/mybatis-spring" 
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
               http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
               http://mybatis.org/schema/mybatis-spring 
               http://mybatis.org/schema/mybatis-spring.xsd"> 
     <mybatis:scan base-package="org.mybatis.spring.sample.mapper" /> 
</beans>

The base-package attribute lets you set the base package for your mapper interface files. You can set more than one package by using a semicolon or comma as a separator. Mappers will be searched for recursively starting in the specified package(s). 

Also, if we have only either one sqlSessionFactory in application context or one sqlSessionTemplate(but not both) we may not specify them in <mybatis:scan/>, but if we have more than one of them - we should. Also attribute is factory-ref or template-ref, but actually it's not a ref. Mybatis-Spring treats to the value pointed in that attribute as to bean name. So, in my opinion the correct meanning of that attributes are factoryBeanName and templateBeanName as known properties in MapperScannerConfigurer.

<mybatis:scan/> element is handled by org.mybatis.spring.config.NamespaceHandler which is pointed as handler in spring.handlers file under META-INF directory of mybatis-spring.jar.This handler just overrides init method and registers the beanDefinitionParser MapperScannerBeanDefinitionParser. This parser scan the packages specified in base-package attribute and creates bean definitions for MapperFactoryBeans. The default behavior involves beans created using BeanDefinition to have autowire-candidate property to be set to true. Then, if we haven't specified sqlSessionFactory-ref or sqlTemplate-ref in <mybatis:scan/> tag, the subclass of ClasspathBeanDefinitionScanner which is used in MapperScannerBeanDefinitionParser sets autowireMode on created bean to be AUTOWIRE_BY_TYPE. Thus, it produces the behavior similiar to @Autowire annotation on setSqlSessionFactory method of MapperFactoryBean