Before this change, calling `StyleSheet::Manager.stylesheet_details`
for the first time resulted in multiple queries to the database. This is
because the code was modelled in a way where each `Theme` was loaded
from the database one at a time.
This PR restructures the code such that it allows us to load all the
theme records in a single query. It also allows us to eager load the
required associations upfront. In order to achieve this, I removed the
support of loading multiple themes per request. It was initially added
to support user selectable theme components but the feature was never
completed and abandoned because it wasn't a feature that we thought was
worth building.
When `Theme#all_theme_variables` returns an empty array, we were running
a pointless query in `StyleSheet::Manager#uploads_digest`.
`SELECT "sha1" FROM "theme_fields" INNER JOIN "uploads" ON
"uploads"."id" = "theme_fields"."upload_id" WHERE 1=0`
Setting a key/value pair in DistributedCache involves waiting on the
write to Redis to finish. In most cases, we don't need to wait on the
setting of the cache to finish. We just need to take our return value
and move on.
The query is being executed each time we try and generate the link path
for a stylesheet within the duration of a reqeust. Categories are not
updated that often so repeating this query multiple times a request is
wasteful.
At the time of this commit, there is a `publish_discourse_stylesheet`
ActiveRecord callback on the `Category` model which clears the cache of
`Stylesheet::Manager` each time a category is saved.
Previously, we only precompiled the CSS for parent themes but not for
the child themes. As a result, the CSS for child themes were being
compiled during the first request which made the respond time high for
that request.
Plugins always store their stylesheets under `/assets/stylesheets`, so we can make the glob pattern much more specific. In my local development environment, this increases the speed of `Stylesheet::Manager.max_file_mtime` from ~65ms to ~3ms (20x faster). This significantly improves stylesheet regeneration time, and the responsiveness of the theme admin UI.
Note that this will have negligible effect in production, because in production the value of `max_file_mtime` is aggressively cached.
When building the `scss_load_paths`, we were creating a full export of the theme (including uploads), and not cleaning it up. With many uploads, this can be extremely slow (because it downloads every upload from S3), and the lack of cleanup could cause a disk to fill up over time.
This commit updates the ZipExporter to provide a `with_export_dir` API, which takes care of cleanup. It also adds a kwarg which allows exporting only extra_scss fields. This should make things much faster for themes with many uploads.
This switches to outputting a separate file for each theme component CSS
asset. We have separate CSS plugin files, separate JS files
(for plugins/themes/components), it makes sense to do the same for
component CSS assets.
Benefits:
- easier debugging
- fixes a regression with theme component sourcemaps
- changes to theme components are updated individually
With HTTP/2, there is also no performance downside to having additional
files in the initial request.
This switches to outputting a separate file for each theme component CSS
asset. We have separate CSS plugin files, separate JS files
(for plugins/themes/components), it makes sense to do the same for
component CSS assets.
Benefits:
- easier debugging
- fixes a regression with theme component sourcemaps
- changes to theme components are updated individually
With HTTP/2, there is also no performance downside to having additional
files in the initial request.
Allows site administrators to pick different fonts for headings in the wizard and in their site settings. Also correctly displays the header logos in wizard previews.
- Lets child components extend color definitions
- Includes default theme color definitions
- Fails gracefully on color stylesheet SCSS errors
- Includes theme variables when extending colors
Adding these classes to the stylesheet link elements in order to toggle dark/light schemes via this theme-component. Eventually this theme-component could possible be merged into core.
Themes can now declare custom colors that get compiled in core's color definitions stylesheet, thus allowing themes to better support dark/light color schemes.
For example, if you need your theme to use tertiary for an element in a light color scheme and quaternary in a dark scheme, you can add the following SCSS to your theme's `color_definitions.scss` file:
```
:root {
--mytheme-tertiary-or-quaternary: #{dark-light-choose($tertiary, $quaternary)};
}
```
And then use the `--mytheme-tertiary-or-quaternary` variable as the color property of that element. You can also use this file to add color variables that use SCSS color transformation functions (lighten, darken, saturate, etc.) without compromising your theme's compatibility with different color schemes.
This fixes an issue where a non-default theme set to use the base color
scheme (i.e. the theme had an empty `color_scheme_id`) was loading the
default theme's color scheme instead.
A first step to adding automatic dark mode color scheme switching. Adds a new SCSS file at `color_definitions.scss` that serves to output all SCSS color variables as CSS custom properties. And replaces all SCSS color variables with the new CSS custom properties throughout the stylesheets.
This is an alpha feature at this point, can only be enabled via console using the `default_dark_mode_color_scheme_id` site setting.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Theme developers can include any number of scss files within the /scss/ directory of a theme. These can then be imported from the main common/desktop/mobile scss.
