Subclass for chained URLs (Imgproxy Pro)

[edtjones]

Hi folks,

I needed to create chained URLs, so I came up with a simple subclass of Imgproxy::Builder which I thought might be useful to others. I just stuck it in a Rails initializer.

Instead of Imgproxy::Builder.new({your: :options}) you pass an array of options as the first argument, and any builder options as the second argument:

Imgproxy::ChainedBuilder.new([{width: 512}, {crop: {height: 340, gravity: :obj}}]).url_for('your-image-url-here')

It's a bit rough, and not worthy of a PR, but I thought it might be useful to others.

module Imgproxy
  class ChainedBuilder < Imgproxy::Builder

    def initialize(option_groups = [], options = {})
      option_groups = option_groups.dup

      @option_groups = option_groups.map do |options|
        Imgproxy::Options.new(options)
      end
      extract_builder_options(options)
      @format = options.delete(:format)

    end

    # build a chained builder. Grouped processing options are an array of the groups of processing options, thus:
    # [
    #   ["width: 1024"],
    #   ["crop:h:300"]
    # ]
    # They need to be on the url separated by a /-/
    def url_for(image)
      path_parts = grouped_processing_options.inject([]) do |a, opts|
        a.push(opts)
        a.push("-")
        a
      end
      path = path_parts.push(url(image, ext: @format)).join("/")
      signature = sign_path(path)
      File.join(Imgproxy.config.endpoint.to_s, signature, path)
    end

    # Build an array of processing options, which will need to be separated by a /-/ in the url
    def grouped_processing_options
      @grouped_processing_options ||= @option_groups.map do |group|
        group.map do |key, value|
          [option_alias(key), value].join(":")
        end
      end
    end
  end
end