Modules and areas

Overview

An area is a logical component that organizes code for optimized request processing. Magento uses areas to streamline web service calls by loading only the dependent code for the specified area. Each of the default areas defined by Magento can contain completely different code on how to process URLs and requests.

For example, if you are invoking a REST web service call, rather than load all the code related to generating user HTML pages, you can specify a separate area that loads code whose scope is limited to answering REST calls.

Magento area types

Magento is organized into these main areas:

Magento Admin (adminhtml): entry point for this area is index.php or pub/index.php. The Admin panel area includes the code needed for store management. The /app/design/adminhtml directory contains all the code for components you’ll see while working in the Admin panel.
Storefront (frontend): entry point for this area is index.php or pub/index.php. The storefront (or frontend) contains template and layout files that define the appearance of your storefront.
Basic (base): used as a fallback for files absent in adminhtml and frontend areas.
Cron (crontab): In pub/cron.php, the \Magento\Framework\App\Cron class always loads the ‘crontab’ area.

You can also send requests to Magento using the SOAP and REST APIs. These two areas

Web API REST (webapi_rest): entry point for this area is index.php or pub/index.php. The REST area has a front controller that understands how to do URL lookups for REST-based URLs.
Web API SOAP (webapi_soap): entry point for this area is index.php or pub/index.php.

How areas work with modules

Modules define which resources are visible and accessible in an area, as well as an area’s behavior. The same module can influence several areas. For instance, the RMA module is represented partly in the adminhtml area and partly in the frontend area.

If your extension works in several different areas, ensure it has separate behavior and view components for each area.

Each area declares itself within a module. All resources specific for an area are located within the same module as well.

You can enable or disable an area within a module. If this module is enabled, it injects an area’s routers into the general application’s routing process. If this module is disabled, Magento will not load an area’s routers and, as a result, an area’s resources and specific functionality are not available.

Module/area interaction guidelines

Modules should not depend on other modules’ areas.
Disabling an area does not result in disabling the modules related to it.
Areas are registered in the Dependency Injection framework di.xml file.

Note about Magento request processing

Magento processes a URL request by first stripping off the base URL. The first path segment of the remaining URL identifies the request area.

After the area name, the URI segment specifies the frontname. When an HTTP request arrives, Magento extracts the handle from the URL and interprets it as follows:

[frontName]/[controller folder]/[controller class]

The frontName is a value defined in the module. Using catalog/product/view as an example:

catalog is the frontName in the module area’s routes.xml file
product is in the controller folder
view is the controller class

For deeper directory structures, the controller folders are separated with an underscore (_). For example:

catalog/product_compare/add = Magento/Catalog/Controller/Product/Compare/Add.php

Note that only the execute() method of any given controller is executed.