mirror of
https://github.com/kremalicious/blog.git
synced 2024-06-30 21:52:05 +02:00
255 lines
9.7 KiB
Ruby
Executable File
255 lines
9.7 KiB
Ruby
Executable File
# Title: Jekyll Picture Tag
|
|
# Authors: Rob Wierzbowski : @robwierzbowski
|
|
# Justin Reese : @justinxreese
|
|
# Welch Canavan : @xiwcx
|
|
#
|
|
# Description: Easy responsive images for Jekyll.
|
|
#
|
|
# Download: https://github.com/robwierzbowski/jekyll-picture-tag
|
|
# Documentation: https://github.com/robwierzbowski/jekyll-picture-tag/readme.md
|
|
# Issues: https://github.com/robwierzbowski/jekyll-picture-tag/issues
|
|
#
|
|
# Syntax: {% picture [preset] path/to/img.jpg [source_key: path/to/alt-img.jpg] [attr="value"] %}
|
|
# Example: {% picture poster.jpg alt="The strange case of responsive images" %}
|
|
# {% picture gallery poster.jpg source_small: poster_closeup.jpg
|
|
# alt="The strange case of responsive images" class="gal-img" data-selected %}
|
|
#
|
|
# See the documentation for full configuration and usage instructions.
|
|
|
|
require 'fileutils'
|
|
require 'pathname'
|
|
require 'digest/md5'
|
|
require 'mini_magick'
|
|
|
|
module Jekyll
|
|
|
|
class Picture < Liquid::Tag
|
|
|
|
def initialize(tag_name, markup, tokens)
|
|
@markup = markup
|
|
super
|
|
end
|
|
|
|
def render(context)
|
|
|
|
# Render any liquid variables in tag arguments and unescape template code
|
|
render_markup = Liquid::Template.parse(@markup).render(context).gsub(/\\\{\\\{|\\\{\\%/, '\{\{' => '{{', '\{\%' => '{%')
|
|
|
|
# Gather settings
|
|
site = context.registers[:site]
|
|
settings = site.config['picture']
|
|
markup = /^(?:(?<preset>[^\s.:\/]+)\s+)?(?<image_src>[^\s]+\.[a-zA-Z0-9]{3,4})\s*(?<source_src>(?:(source_[^\s.:\/]+:\s+[^\s]+\.[a-zA-Z0-9]{3,4})\s*)+)?(?<html_attr>[\s\S]+)?$/.match(render_markup)
|
|
preset = settings['presets'][ markup[:preset] ] || settings['presets']['default']
|
|
|
|
raise "Picture Tag can't read this tag. Try {% picture [preset] path/to/img.jpg [source_key: path/to/alt-img.jpg] [attr=\"value\"] %}." unless markup
|
|
|
|
# Assign defaults
|
|
settings['source'] ||= '.'
|
|
settings['output'] ||= 'generated'
|
|
settings['markup'] ||= 'picturefill'
|
|
|
|
# Prevent Jekyll from erasing our generated files
|
|
site.config['keep_files'] << settings['output'] unless site.config['keep_files'].include?(settings['output'])
|
|
|
|
# Deep copy preset for single instance manipulation
|
|
instance = Marshal.load(Marshal.dump(preset))
|
|
|
|
# Process alternate source images
|
|
source_src = if markup[:source_src]
|
|
Hash[ *markup[:source_src].gsub(/:/, '').split ]
|
|
else
|
|
{}
|
|
end
|
|
|
|
# Process html attributes
|
|
html_attr = if markup[:html_attr]
|
|
Hash[ *markup[:html_attr].scan(/(?<attr>[^\s="]+)(?:="(?<value>[^"]+)")?\s?/).flatten ]
|
|
else
|
|
{}
|
|
end
|
|
|
|
if instance['attr']
|
|
html_attr = instance.delete('attr').merge(html_attr)
|
|
end
|
|
|
|
if settings['markup'] == 'picturefill'
|
|
html_attr['data-picture'] = nil
|
|
html_attr['data-alt'] = html_attr.delete('alt')
|
|
end
|
|
|
|
html_attr_string = html_attr.inject('') { |string, attrs|
|
|
if attrs[1]
|
|
string << "#{attrs[0]}=\"#{attrs[1]}\" "
|
|
else
|
|
string << "#{attrs[0]} "
|
|
end
|
|
}
|
|
|
|
# Prepare ppi variables
|
|
ppi = if instance['ppi'] then instance.delete('ppi').sort.reverse else nil end
|
|
# this might work??? ppi = instance.delete('ppi'){ |ppi| [nil] }.sort.reverse
|
|
ppi_sources = {}
|
|
|
|
# Switch width and height keys to the symbols that generate_image() expects
|
|
instance.each { |key, source|
|
|
raise "Preset #{key} is missing a width or a height" if !source['width'] and !source['height']
|
|
instance[key][:width] = instance[key].delete('width') if source['width']
|
|
instance[key][:height] = instance[key].delete('height') if source['height']
|
|
}
|
|
|
|
# Store keys in an array for ordering the instance sources
|
|
source_keys = instance.keys
|
|
|
|
# Raise some exceptions before we start expensive processing
|
|
raise "Picture Tag can't find the \"#{markup[:preset]}\" preset. Check picture: presets in _config.yml for a list of presets." unless preset
|
|
raise "Picture Tag can't find this preset source. Check picture: presets: #{markup[:preset]} in _config.yml for a list of sources." unless (source_src.keys - source_keys).empty?
|
|
|
|
# Process instance
|
|
# Add image paths for each source
|
|
instance.each_key { |key|
|
|
instance[key][:src] = source_src[key] || markup[:image_src]
|
|
}
|
|
|
|
# Construct ppi sources
|
|
# Generates -webkit-device-ratio and resolution: dpi media value for cross browser support
|
|
# Reference: http://www.brettjankord.com/2012/11/28/cross-browser-retinahigh-resolution-media-queries/
|
|
if ppi
|
|
instance.each { |key, source|
|
|
ppi.each { |p|
|
|
if p != 1
|
|
ppi_key = "#{key}-x#{p}"
|
|
|
|
ppi_sources[ppi_key] = {
|
|
:width => if source[:width] then (source[:width].to_f * p).round else nil end,
|
|
:height => if source[:height] then (source[:height].to_f * p).round else nil end,
|
|
'media' => if source['media']
|
|
"#{source['media']} and (-webkit-min-device-pixel-ratio: #{p}), #{source['media']} and (min-resolution: #{(p * 96).round}dpi)"
|
|
else
|
|
"(-webkit-min-device-pixel-ratio: #{p}), (min-resolution: #{(p * 96).to_i}dpi)"
|
|
end,
|
|
:src => source[:src]
|
|
}
|
|
|
|
# Add ppi_key to the source keys order
|
|
source_keys.insert(source_keys.index(key), ppi_key)
|
|
end
|
|
}
|
|
}
|
|
instance.merge!(ppi_sources)
|
|
end
|
|
|
|
# Generate resized images
|
|
instance.each { |key, source|
|
|
instance[key][:generated_src] = generate_image(source, site.source, site.dest, settings['source'], settings['output'])
|
|
}
|
|
|
|
# Construct and return tag
|
|
if settings['markup'] == 'picturefill'
|
|
|
|
source_tags = ''
|
|
# Picturefill uses reverse source order
|
|
# Reference: https://github.com/scottjehl/picturefill/issues/79
|
|
source_keys.reverse.each { |source|
|
|
media = " data-media=\"#{instance[source]['media']}\"" unless source == 'source_default'
|
|
source_tags += "<span data-src=\"#{instance[source][:generated_src]}\"#{media}></span>\n"
|
|
}
|
|
|
|
# Note: we can't indent html output because markdown parsers will turn 4 spaces into code blocks
|
|
picture_tag = "<span #{html_attr_string}>\n"\
|
|
"#{source_tags}"\
|
|
"<noscript>\n"\
|
|
"<img src=\"#{instance['source_default'][:generated_src]}\" alt=\"#{html_attr['data-alt']}\">\n"\
|
|
"</noscript>\n"\
|
|
"</span>\n"
|
|
|
|
elsif settings['markup'] == 'picture'
|
|
|
|
source_tags = ''
|
|
source_keys.each { |source|
|
|
if source == 'source_default'
|
|
source_tags += "<img src=\"#{instance[source][:generated_src]}\" alt=\"#{html_attr['alt']}\">\n"
|
|
else
|
|
source_tags += "<source src=\"#{instance[source][:generated_src]}\" media=\"#{instance[source]['media']}\">\n"
|
|
end
|
|
}
|
|
|
|
# Note: we can't indent html output because markdown parsers will turn 4 spaces into code blocks
|
|
picture_tag = "<picture #{html_attr_string}>\n"\
|
|
"#{source_tags}"\
|
|
"<p>#{html_attr['alt']}</p>\n"\
|
|
"</picture>"
|
|
end
|
|
|
|
# Return the markup!
|
|
picture_tag
|
|
end
|
|
|
|
def generate_image(instance, site_source, site_dest, image_source, image_dest)
|
|
|
|
image = MiniMagick::Image.open(File.join(site_source, image_source, instance[:src]))
|
|
digest = Digest::MD5.hexdigest(image.to_blob).slice!(0..5)
|
|
|
|
image_dir = File.dirname(instance[:src])
|
|
ext = File.extname(instance[:src])
|
|
basename = File.basename(instance[:src], ext)
|
|
|
|
orig_width = image[:width].to_f
|
|
orig_height = image[:height].to_f
|
|
orig_ratio = orig_width/orig_height
|
|
|
|
gen_width = if instance[:width]
|
|
instance[:width].to_f
|
|
elsif instance[:height]
|
|
orig_ratio * instance[:height].to_f
|
|
else
|
|
orig_width
|
|
end
|
|
gen_height = if instance[:height]
|
|
instance[:height].to_f
|
|
elsif instance[:width]
|
|
instance[:width].to_f / orig_ratio
|
|
else
|
|
orig_height
|
|
end
|
|
gen_ratio = gen_width/gen_height
|
|
|
|
# Don't allow upscaling. If the image is smaller than the requested dimensions, recalculate.
|
|
if orig_width < gen_width || orig_height < gen_height
|
|
undersize = true
|
|
gen_width = if orig_ratio < gen_ratio then orig_width else orig_height * gen_ratio end
|
|
gen_height = if orig_ratio > gen_ratio then orig_height else orig_width/gen_ratio end
|
|
end
|
|
|
|
gen_name = "#{basename}-#{gen_width.round}*#{gen_height.round}-#{digest}#{ext}"
|
|
gen_dest_dir = File.join(site_dest, image_dest, image_dir)
|
|
gen_dest_file = File.join(gen_dest_dir, gen_name)
|
|
|
|
# Generate resized files
|
|
unless File.exists?(gen_dest_file)
|
|
|
|
warn "Warning:".yellow + " #{instance[:src]} is smaller than the requested output file. It will be resized without upscaling." if undersize
|
|
|
|
# If the destination directory doesn't exist, create it
|
|
FileUtils.mkdir_p(gen_dest_dir) unless File.exist?(gen_dest_dir)
|
|
|
|
# Let people know their images are being generated
|
|
puts "Generating #{gen_name}"
|
|
|
|
# Scale and crop
|
|
image.combine_options do |i|
|
|
i.resize "#{gen_width}x#{gen_height}^"
|
|
i.gravity "center"
|
|
i.crop "#{gen_width}x#{gen_height}+0+0"
|
|
end
|
|
|
|
image.write gen_dest_file
|
|
end
|
|
|
|
# Return path relative to the site root for html
|
|
Pathname.new(File.join('/', image_dest, image_dir, gen_name)).cleanpath
|
|
end
|
|
end
|
|
end
|
|
|
|
Liquid::Template.register_tag('picture', Jekyll::Picture)
|