我应该使用App :: import（'Model'，…）还是ClassRegistry（…）？

Question

Because of other answers ( like this ), I'm just wanting to clarify what should be used in CakePHP 1.3 .

Specifically, I have a situation that calls for a Model to depend on another, so from a method in that Model I'd like to load another, do some stuff with the info, etc.

The documentation for the App Class says:

In previous versions there were different functions for loading a needed class based on the type of class you wanted to load. These functions have been deprecated, all class and library loading should be done through App::import() now.

I'm assuming this covers the use of ClassRegistry , etc, but I just want to it to be clear, and certain:

Should I use App::import('Model', ...) to utilize one Model from another, or something else? If something else, what?

Answer 1

It appears that, even two years since 2008, the best method is to use ClassRegistry::init() , despite the cited documentation.

This is made evident in the actual API/documentation for the specific classes/methods.

App::import()

Finds classes based on $name or specific file(s) to search. Calling App::import() will not construct any classes contained in the files. It will only find and require() the file.

ClassRegistry::init()

Loads a class, registers the object in the registry and returns instance of the object.

Examples Simple Use: Get a Post model instance ClassRegistry::init('Post');

As you can see, even the API Documentation points out examples of using ClassRegistry to load models, instantiating them for you, as opposed to App::import (which does much less), and despite the changed wording in the CakePHP "Book" documentation.

Answer 2

If you can relate the models then the best way is to Dynamically bind the relations using

$this->bindModel("hasOne" => array("Model2")) .

If you can't relate the model and you want to use the second model in just one occurrence then you can use

ClassRegistry::init('Model2')->find('allThatIWant');

if you want to use it in several occurrence then you must try

$this->model2 = & ClassRegistry::init('Model2') 
$this->model2->find('allThatIWant');

Answer 3

As of 2.6.x of course it is ClassRegistry::init() still.

There is a major difference. App::import will just include/require it. On the other hand ClassRegistry::init() will instantiate it and fetch you a fully loaded object of the model.

So to say, for example you loaded a model in beforeFilter of your AppController. You add some custom properties to it using $this->Model->__something . Now you do call ClassRegistry::init('Model') somewhere where you do not have $controller object available, for example, in a behavior. The object returned by ClassRegistry::init('Model') will have your custom property $this->Model->__something in tact.

Btw, $controller->loadModel() seems the ideal way to load model where you have a $controller object available, for example in your components.

Answer 4

$this->loadModel('model name')会$this->loadModel('model name') ，除非您需要整个控制器使用，然后只需在模型中定义关系，例如hasone，belongsed ...，然后调用$this->model->model2 。