discourse/lib/theme_screenshots_handler.rb
Yuriy Kurant a76a4430c7
DEV: enhance file type support for theme and component screenshots (#36372)
Updates supported file types for theme and component screenshots.

### Reasoning
Switching to `.webp` makes themes lighter. In official themes we
measured:
- ~60% smaller compared to `.png`
- ~35% smaller compared to `.jpg`

`.png`, `.jpg`, and `.jpeg` remain supported.

### Changes
* Dropped `.gif` support
* Added `.webp` support (static + animated)

---

More details:
https://meta.discourse.org/t/adding-metadata-and-screenshots-to-a-theme/119205.
2025-12-02 13:12:11 +08:00

89 lines
3.1 KiB
Ruby

# frozen_string_literal: true
class ThemeScreenshotsHandler
MAX_THEME_SCREENSHOT_FILE_SIZE = 1.megabyte
MAX_THEME_SCREENSHOT_DIMENSIONS = [3840, 2160] # 4K resolution
MAX_THEME_SCREENSHOT_COUNT = 2
THEME_SCREENSHOT_ALLOWED_FILE_TYPES = %w[.jpeg .jpg .png .webp].freeze
class ThemeScreenshotError < StandardError
end
def initialize(theme)
@theme = theme
end
# Screenshots here come from RemoteTheme.extract_theme_info, which
# in turn parses the theme about.json file, which is where screenshots
# are defined.
def parse_screenshots_as_theme_fields!(screenshots, theme_importer)
updated_theme_fields = []
screenshots = Array.wrap(screenshots).take(MAX_THEME_SCREENSHOT_COUNT)
screenshots.each do |relative_path|
path = theme_importer.real_path(relative_path)
next if !path.present?
screenshot_filename = File.basename(path)
screenshot_extension = File.extname(path)
if !THEME_SCREENSHOT_ALLOWED_FILE_TYPES.include?(screenshot_extension)
raise ThemeScreenshotError,
I18n.t(
"themes.import_error.screenshot_invalid_type",
file_name: screenshot_filename,
accepted_formats: THEME_SCREENSHOT_ALLOWED_FILE_TYPES.join(","),
)
end
if File.size(path) > MAX_THEME_SCREENSHOT_FILE_SIZE
raise ThemeScreenshotError,
I18n.t(
"themes.import_error.screenshot_invalid_size",
file_name: screenshot_filename,
max_size:
ActiveSupport::NumberHelper.number_to_human_size(MAX_THEME_SCREENSHOT_FILE_SIZE),
)
end
screenshot_width, screenshot_height = FastImage.size(path)
if (screenshot_width.nil? || screenshot_height.nil?) ||
screenshot_width > MAX_THEME_SCREENSHOT_DIMENSIONS[0] ||
screenshot_height > MAX_THEME_SCREENSHOT_DIMENSIONS[1]
raise ThemeScreenshotError,
I18n.t(
"themes.import_error.screenshot_invalid_dimensions",
file_name: screenshot_filename,
width: screenshot_width.to_i,
height: screenshot_height.to_i,
max_width: MAX_THEME_SCREENSHOT_DIMENSIONS[0],
max_height: MAX_THEME_SCREENSHOT_DIMENSIONS[1],
)
end
upload =
RemoteTheme.create_upload(
theme: @theme,
path: path,
relative_path: relative_path,
skip_validations: true,
)
if !upload.errors.empty?
raise ThemeScreenshotError,
I18n.t(
"themes.import_error.screenshot",
errors: upload.errors.full_messages.join(","),
)
end
screenshot_filename_clean =
FileHelper.sanitize_filename(screenshot_filename.gsub(screenshot_extension, ""))
updated_theme_fields << @theme.set_field(
target: :common,
name: "screenshot_#{screenshot_filename_clean}",
type: :theme_screenshot_upload_var,
upload_id: upload.id,
)
end
updated_theme_fields
end
end