在Kyma plugin初始化时，把updateRegistration这个函数作为activated_plugin和deactivated_plugin事件的事件处理函数：
Actions are the hooks that the WordPress core launches at specific points
- during execution, or when specific events occur. Plugins can specify that
- one or more of its PHP functions are executed at these points, using the
- Action API.
相当于ABAP Netweaver里的BAdI definition和BAdI implementation
要获取更多Jerry的原创文章，请关注公众号"汪子熙":