Detailed explanation of ThinkPHP development framework functions: C method_php skills

C method is the method used by ThinkPHP to set, obtain, and save configuration parameters, and is used more frequently.

To understand the C method, you need to first understand the configuration of ThinkPHP, because all operations of the C method are related to the configuration. ThinkPHP's configuration file is defined in PHP array format.

Due to the function overloading design, there are many uses. Let’s explain them one by one.

Set parameters

C('DB_NAME','thinkphp');

indicates that the value of the DB_NAME configuration parameter is set to thinkphp. Since the configuration parameters are not case-sensitive, the following writing method is the same:

C('DB_NAME','thinkphp');

However, it is recommended to keep the configuration definition specifications in uniform capitalization.

All parameters of the project can be dynamically changed through this method before taking effect. The last set value will overwrite the definition in the previous settings or conventional configuration. You can also use the parameter configuration method to add new configurations.

Supports the setting of secondary configuration parameters, such as:

C('USER.USER_ID',8);

Configuration parameters are not recommended to exceed level two.

If you want to set multiple parameters, you can use batch settings, for example:

$config['user_id'] = 1;
$config['user_type'] = 1;
C($config);

If the first parameter of the C method is passed into an array, it means batch assignment. The above assignment is equivalent to:

C('USER_ID',1);
C('USER_TYPE',1);

Get parameters

To get the set parameters, you can use:

$userId = C('USER_ID');
$userType = C('USER_TYPE');

If the USER_ID parameter has not been defined, NULL is returned.

can also support obtaining secondary configuration parameters, for example:

$userId = C('USER.USER_ID');

If the incoming configuration parameters are empty, it means getting all parameters:

$config = C();

Save settings

Version 3.1 adds a function to permanently save setting parameters, only for batch assignment, for example:

$config['user_id'] = 1;
$config['user_type'] = 1;
C($config,'name');

After setting the config parameters in batches, all current configuration parameters will be saved to the cache file (or other configured caching methods).

After saving, if you want to retrieve the saved parameters, you can use

$config = C('','name');

The name is the cache identifier used when saving parameters earlier. It must be consistent to correctly retrieve the saved parameters. The retrieved parameters will be merged with the current configuration parameters, without manual merging.

The code is as follows:

class TestAction extends Action{
  /**
   * $config['user_id'] = 1;
    $config['user_type'] = 1;
    C($config);
      如果C方法的第一个参数传入数组，就表示批量赋值，上面的赋值相当于：
    C('USER_ID',1);
    C('USER_TYPE',1);
      获取参数
      要获取设置的参数，可以用：
    $userId = C('USER_ID');
    $userType = C('USER_TYPE');
   */
  public function index(){
    C('USER_ID',102);  //给参数赋值
    C('USER_TYPE',107); //给参数赋值
    dump(C('USER_ID')).'<br/>';//102=>获取设置的参数
    dump(C('USER_TYPE')).'<br/>';//107=>获取设置的参数
    $this->display();
  }
}