Class: JekyllThumbnail

Inherits:
Liquid::Tag
  • Object
show all
Defined in:
lib/jekyll-thumbnail.rb

Instance Method Summary collapse

Constructor Details

#initialize(tag_name, markup, tokens) ⇒ JekyllThumbnail 



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# File 'lib/jekyll-thumbnail.rb', line 20

def initialize(tag_name, markup, tokens)
  if /(?<source>[^\s]+)\s+(?<dimensions>[^\s]+)/i =~ markup
    @source = source
    @dimensions = dimensions
  end
  super
end

Instance Method Details

#look_up(context, name) ⇒ Object

look up liquid variables source: stackoverflow.com/a/8771374/1489823



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# File 'lib/jekyll-thumbnail.rb', line 10

def look_up(context, name)
  lookup = context

  name.split(".").each do |value|
    lookup = lookup[value]
  end

  lookup
end

#render(context) ⇒ Object 



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# File 'lib/jekyll-thumbnail.rb', line 28

def render(context)
  if @source

    # parking

    # also put the parameters into the liquid parser again, to allow variable paths

    source = @source
    source = look_up context, source unless File.readable?(source)
    dimensions = @dimensions

    source_path = "#{source}"
    raise "#{source_path} is not readable" unless File.readable?(source_path)
    ext = File.extname(source)
    desc = dimensions.gsub(/[^\da-z]+/i, '')
    dest_dir = "#{File.dirname(source)}/thumbs"
    Dir.mkdir dest_dir unless Dir.exists? dest_dir
    dest = "#{dest_dir}/#{File.basename(source, ext)}_#{desc}#{ext}"
    dest_path = "#{dest}"

    # only thumbnail the image if it doesn't exist tor is less recent than the source file

    # will prevent re-processing thumbnails for a ton of images...

    if !File.exists?(dest_path) || File.mtime(dest_path) <= File.mtime(source_path)
      # puts ENV.inspect


      puts "Thumbnailing #{source} to #{dest} (#{dimensions})"

      image = MiniMagick::Image.open(source_path)
      image.strip
      image.resize dimensions
      image.quality 60

      second_image = MiniMagick::Image.new("img/watermark-#{dimensions}.png")

      result = image.composite(second_image) do |c|
        c.compose "Over"    # OverCompositeOp

        c.geometry "+20+20" # copy second_image onto first_image from (20, 20)

      end

      result.write dest_path
    end

    """<img src='#{dest}' />"""

    # TODO support relative paths

  else
    "Could not create thumbnail for #{source}. Usage: thumbnail /path/to/local/image.png 50x50"
  end
end