Class: PictureTag::Parsers::ImageBackend

Inherits:
Object
  • Object
show all
Defined in:
lib/jekyll_picture_tag/parsers/image_backend.rb

Overview

Returns information regarding image handlers

Instance Method Summary collapse

Instance Method Details

#all_names(format) ⇒ Object

Returns an array of all known names of a format, for the purposes of parsing supported output formats.



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# File 'lib/jekyll_picture_tag/parsers/image_backend.rb', line 50

def all_names(format)
  alts = alternates.select { |a| a.include? format }.flatten
  alts.any? ? alts : [format]
end

#handler_for(format) ⇒ Object 



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# File 'lib/jekyll_picture_tag/parsers/image_backend.rb', line 5

def handler_for(format)
  if (vips_formats & all_names(format)).any?
    :vips
  elsif (magick_formats & all_names(format)).any?
    :magick
  else
    raise error_string(format)
  end
end

#magick_formats ⇒ Object

Returns an array of formats that imagemagick can handle.



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# File 'lib/jekyll_picture_tag/parsers/image_backend.rb', line 30

def magick_formats
  if command?('magick')
    @magick_formats ||= `magick -version`
                        .scan(/Delegates.*/)
                        .first
                        .delete_prefix('Delegates (built-in):')
                        .split
  elsif command?('convert')
    @magick_formats ||= `convert -version`
                        .scan(/Delegates.*/)
                        .first
                        .delete_prefix('Delegates (built-in):')
                        .split
  else
    @magick_formats = []
  end
end

#vips_formats ⇒ Object

Returns array of formats that vips can save to



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# File 'lib/jekyll_picture_tag/parsers/image_backend.rb', line 16

def vips_formats
  if command?('vips')
    @vips_formats ||= `vips -l`
                      .split('/n')
                      .select { |line| line.include? 'ForeignSave' }
                      .flat_map { |line| line.scan(/\.[a-z]{1,5}/) }
                      .map { |format| format.strip.delete_prefix('.') }
                      .uniq
  else
    @vips_formats = []
  end
end