Building reusable functionality

Add modules, models, controllers, and event handlers.

Choose the task that matches what you need to do. The pages explain the relevant workflow and link to related guides and reference material. Examples use the local site garden; use your own site name and check the command’s scope before running it.

In this section

1Create a reusable moduleCreate apps_user/zotonic_mod_garden with the following files. This example adds a discoverable module without starting an extra process.
2Choose a model, controller, observer, or componentChoose a model, controller, observer, or component.
3Expose data through a modelCreate src/models/m_garden.erl in the Garden module. This complete example exposes a public greeting:
4Add an HTTP controllerUse controller_template when a dispatch rule only needs to render a template. Write a custom controller when the endpoint needs additional request processing or response behavior.
5Respond to a notificationFind the notification definition and inspect its callers before implementing an observer. The notifier operation determines whether observers collect results, stop at a first result, or fold a value.
6Add a filter or rendering componentUse a filter for a small transformation of an input value. Keep missing and unexpected values predictable, and escape output at the point where it becomes HTML.
7Upgrade a module's data schemaVersion schema changes through the module's installation and upgrade mechanism. Inspect a module using -mod_schema and manage_schema/2 before adding your own versioned step.
8Run work outside a requestUse an existing Zotonic task mechanism when it fits the job. Use a supervised worker when the work needs a persistent process with its own lifecycle.