Detailed explanation of ThinkPHP empty module and empty operation

ThinkPHP's empty module and empty operations are also very practical functions. The concept of empty module is that when ThinkPHP cannot find the specified module, it will try to locate the empty module (EmptyAction) and execute the index operation in the empty module. Similarly, empty operation is the same concept. When the system cannot find the operation method under the specified module, it will try to locate the empty operation method (empty). In fact, it is easy to understand. It is a bit similar to the custom 404 page in the PHP virtual host, but it is more flexible than the custom 404. Using this mechanism, we can implement the optimization of error pages and some URLs. The following is a detailed introduction to the writing of empty modules and empty operations.

1. Empty module, define the EmptyAction class in the project:

&lt;?php
public class EmptyAction extends Action {
public function index(){
echo "The current module does not exist";
  }
 }
?&gt;

This is a simple empty module class. Of course, you can also do some more complex operations in it. Everything has to be written according to the needs of the project. This is just a demonstration.

2. Empty operation, the empty operation is defined under the specified module. For example, we define an empty operation under the User module, that is, the UserAction class.

&lt;?php
class UserAction extends Action
{
public function index()
{
$this-&gt;display();
  }
public function demo(){$this-&gt;display();
  }
public function _empty(){
   //This method is an empty operation   echo 'The current operation does not exist';
  }
 }
?&gt;

The code is very simple, this is an empty method, and the empty module and empty operations can also be used at the same time to complete more complex operations.