Allow extra config files to be listed via cli

[danielevans]

In applications with complex entities having the ability to generate multiple ERDs with different settings is useful. For example, each diagram could be focused on a specific segment of the data model.

[kerrizor]

First off, thank you for submitting this AND for having patience with my tardy response.

I like this, but am going to put off merging this because I need to solve the split between the CLI and rake task invocations for v1.6 (#289)

[sfcgeorge]

This is what I have done in our app to allow multiple graphs. I've got the default top level one, then graphs for each sub-section of the app with a config file each.

if Rails.env.development?
  Rake::Task["db:migrate"].enhance do
    Rake::Task["erd"].invoke

    Dir.glob(".erdconfig_*").each do |f|
      puts "Loading #{f}"

      # Set default title & filename which can be overridden in .erdconfig_*
      name = f.split("_").last
      ENV["title"] = name.titleize
      ENV["filename"] = "erd_#{name}"

      YAML.load_file(f).each do |key, value|
        value = value.join(",") if value.is_a?(Array)
        ENV[key.to_s] = value.to_s
      end

      Rake::Task["erd"].reenable
      Rake::Task["erd:options"].reenable
      Rake::Task["erd:generate"].reenable
      Rake::Task["erd"].invoke
    end
  end
end

[kerrizor]

Closing in favor of #326, a rebase of this PR. Thank you for the contribution (and your patience!) @danielevans