4.22. Other Model Types

In your website, you will typically divide your principal model types (described above) into subtypes. For example, you will have:

• Forms. Forms are models whose purpose is to collect data entered by web user. Forms are a subtype of entities. You will typically store forms in APP_DIR/module/Application/src/Form directory.

• Filters. Filters are designed for transforming input data. Filters are a subtype of services. You will typically store filters in APP_DIR/module/Application/src/Filter directory.

• Validators. Validators are used for checking input data for correctness. Validators are also a subtype of services. You will typically store validators in APP_DIR/module/Application/src/Validator directory.

• View Helpers. They encapsulate some page rendering functionality. View helpers are similar to services. You will typically store view helpers in APP_DIR/module/Application/src/View/Helper directory.

• Routes. Routes are a specific service model used for implementing custom mapping rules between URLs and your controllers. You will typically store custom routes in APP_DIR/module/Application/src/Route directory.

So, eventually you will have the following typical directory structure of your website's module:

/Application/src
	/Controller
		/Factory
        /Plugin
            /Factory
	/Entity
	/Filter
	/Form
    /Repository
	/Route
	/Service
		/Factory
	/Validator
    /ValueObject
	/View
		/Helper
            /Factory

It is possible to have arbitrarily many model subtypes. The more complex is your application, the more model subtypes you may have.