Module: JekyllAutoThumbnails::Scanner

Defined in:
lib/jekyll-auto-thumbnails/scanner.rb

Overview

HTML scanning for images

Class Method Summary collapse

Class Method Details

.image_dimensions(file_path) ⇒ Array<Integer, Integer>?

Get image dimensions from file

Parameters:

  • file_path (String) —

    path to image file

Returns:

  • (Array<Integer, Integer>, nil) —
    width, height

    or nil



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# File 'lib/jekyll-auto-thumbnails/scanner.rb', line 80

def self.image_dimensions(file_path)
  # Use ImageMagick identify command (shell-free, cross-platform)
  # Use [0] to get only first frame (important for animated GIFs)
  # Wrapper handles both ImageMagick v6 and v7
  output, status = ImageMagickWrapper.execute_identify("-format", "%wx%h", "#{file_path}[0]")
  return nil unless status.success? && !output.strip.empty?

  width, height = output.strip.split("x").map(&:to_i)
  [width, height]
rescue StandardError
  nil
end

.scan_html(html, registry, config, site_source = nil) ⇒ Object

Scan HTML for images needing optimization

Parameters:

  • html (String) —

    HTML content

  • registry (Registry) —

    image registry

  • config (Configuration) —

    configuration

  • site_source (String) (defaults to: nil) —

    Jekyll site source (optional, for unsized image checking)



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# File 'lib/jekyll-auto-thumbnails/scanner.rb', line 17

def self.scan_html(html, registry, config, site_source = nil)
  doc = HtmlParser.parse(html, config.parser)

  # Only process images in <article> tags
  doc.css("article img").each do |img|
    src = img["src"]
    next unless src
    next if UrlResolver.external?(src)

    # Check for explicit dimensions
    width = parse_dimension(img["width"])
    height = parse_dimension(img["height"])

    if width || height
      # Explicitly sized - calculate missing dimension if needed
      if site_source && (width.nil? || height.nil?)
        Jekyll.logger.debug "AutoThumbnails:", "Calculating dimensions for #{src} (#{width}x#{height})"
        width, height = calculate_dimensions(src, width, height, site_source)
        Jekyll.logger.debug "AutoThumbnails:", "Calculated: #{width}x#{height}"
      end

      # Skip if dimensions match original (no thumbnail needed)
      if site_source && dimensions_match_original?(src, width, height, site_source)
        Jekyll.logger.debug "AutoThumbnails:", "Skipping #{src} - dimensions match original"
        next
      end

      Jekyll.logger.debug "AutoThumbnails:", "Registering #{src} at #{width}x#{height}"
      registry.register(src, width, height)
    elsif site_source && (config.max_width || config.max_height)
      # Unsized but max config exists - check actual dimensions
      check_and_register_oversized(src, registry, config, site_source)
    end
  end
end