GoPress Docs
Docs / Hook System

Hook System

GoPress provides a WordPress-style hook bus with actions and filters. It is the main extension mechanism for plugins and a useful customization point for themes.

Actions

Actions are event notifications. They do not return a value.

handle := engine.Hooks.AddAction("content.saved", func(args ...interface{}) {
    // react to content changes
}, 10)

Filters

Filters receive a value, modify it, and return the updated value.

handle := engine.Hooks.AddFilter("seo.content.meta", func(value interface{}, args ...interface{}) interface{} {
    return value
}, 10)

Priority controls execution order. Lower numbers run earlier.

Removing Hooks

Plugins must keep returned handles and remove them during deactivation:

engine.Hooks.RemoveFilter(handle)

This is required for plugin hot-disable behavior. A disabled plugin should not keep modifying frontend output, admin forms, SEO data, sitemap entries, or menus.

Common Hook Areas

  • Admin content form fields and save actions.
  • SEO metadata transformation.
  • Sitemap URL transformation.
  • Frontend template slots.
  • Menu location resolution.
  • Content list tabs and admin UI extensions.

Hooks should carry stable, documented payloads. If a hook needs too many assumptions about a theme or plugin, it probably belongs behind a smaller core interface.