Foundation

How the framework underneath every extension is put together: what is on disk, what a request runs through, how your classes are found, how extensions reach each other, and the handful of names an extension uses constantly.

Read this section once before you write an extension. Most of what goes wrong early — a class that will not load, a facade that fatals, a plugin nothing calls, a directory that is not an extension because no database row says so — is in here, and none of it is discoverable by reading a component.

In this section

• Structure — the directory layout, what belongs in core/ against app/, and the request lifecycle end to end.
• Constants — the paths, the version, and the entry guard.
• Autoloading — how a class name becomes a file, and what to check when it does not.
• Events — how extensions reach each other, and why an event sometimes reaches nobody.
• Extensions — what a component, plugin, module, and template are, and how the platform finds them.
• Facades — the short names for the container's services, and the import rule that makes them work. The one to read.
• Service providers — how those services are registered and resolved, and how to add one.