discourse/lib/site_settings
Martin Brennan 19af83d39e
FEATURE: Themeable site settings (#32233)
This commit introduces the concept of themeable site settings,
which is a new tool for theme authors that lives alongside theme
modifiers and theme settings. Here is a quick summary:

* Theme settings - These are custom settings used to control UI and functionality within your theme or component and provide configuration options. These cannot change core Discourse functionality.
* Theme modifiers - Allows a theme or a component to modify selected server-side functionality of core Discourse as an alternative to building a plugin.
* Themeable site settings (new) - Allows a theme (not components) to override a small subset of core site settings, which generally control parts of the UI and other minor functionality. This allows themes to have a greater control over the full site experience.

Themeable site settings will be shown for all themes, whether the theme
changes
the value or not, and have a similar UI to custom theme settings.

We are also introducing a new page at
`/admin/config/theme-site-settings` that
allows admins to see all possible themeable site settings, and which
themes
are changing the value from the default.

### Configuration

Theme authors can configure initial values themeable site settings using
a section in the `about.json` file like so:

```json
"theme_site_settings": {
  "search_experience": "search_field"
}
```

These values will not change when the theme updates, because we cannot
know if admins have manually changed them.

### Limitations

Themeable site settings are only really intended to control elements of
the UI, and when retrieving their value we require a theme ID, so these
limitations apply:

- Themeable site settings cannot be used in Sidekiq jobs
- Themeable site settings cannot be used in markdown rules
- Themeable site settings will be cached separately to client site
settings using theme ID as a key
- Themeable site settings will override keys on the `siteSettings`
service on the client using the application preloader
- `SiteSetting.client_settings_json` will not include themeable site
settings, instead you can call `SiteSetting.theme_site_settings_json`
with a theme ID

### Initial settings

There are only two site settings that will be themeable to begin with:

* `enable_welcome_banner`
* `search_experience`

And our new Horizon theme will take advantage of both. Over time, more
settings that control elements of the UI will be exposed this way.
2025-07-16 11:00:21 +10:00
..
db_provider.rb DEV: Apply syntax_tree formatting to lib/* 2023-01-09 12:10:19 +00:00
defaults_provider.rb DEV: Fix various rubocop lints (#24749) 2023-12-06 23:25:00 +01:00
deprecated_settings.rb FEATURE: Themeable site settings (#32233) 2025-07-16 11:00:21 +10:00
hidden_provider.rb DEV: support un-hiding site settings programmatically (#32824) 2025-05-20 21:44:56 +02:00
label_formatter.rb DEV: Add "UI" as a humanizable acronym (#33322) 2025-06-24 15:42:35 +10:00
local_process_provider.rb DEV: Apply syntax_tree formatting to lib/* 2023-01-09 12:10:19 +00:00
type_supervisor.rb FEATURE: porting type object to site settings (#32706) 2025-05-13 14:30:24 -03:00
validations.rb DEV: Add setting to tag s3 objects enabling tag based access control policies (#32988) 2025-06-16 13:26:18 +08:00
yaml_loader.rb DEV: Remove older ruby version logic (#19971) 2023-01-24 10:42:56 +00:00