In Drupal 8, a service is any object managed by the services container. Drupal 8 introduces the concept of services to decouple reusable functionality and makes these services pluggable and replaceable by registering them with a service container. Services are used to perform operations like accessing the database or sending an e-mail.
Using below example we can check if module is installed or not :
Modules are used to extend and customize Drupal Core. To install module normally we can navigate to "Admin => Extend" link in toolbar.
Like older versions of Drupal, Drupal 8 doesn't allow modules to be enable / disable. The only thing we can do is either install a module or completely uninstall it.
Below example shows how to install module using code:
In Drupal 8, module's weight is stored into ConfigFactory. Here's how to get or set module weight.
Get module weight:
When building sites, many client wants users to get redirected to particular page (like Site Home Page) or page based on User Roles. Today we'll see how we can redirect user after login to particular page.
NOTE: I've defined my own custom page using [MODULENAME].routing.yml named as "custom.redirect_callback", which we'll be using for redirecting user.