Railtie(gem): How do i include and render erb partials?

Question

I'm working on a Railtie(gem) for embedding videos like YouTube, Vimeo etc.

In this gem i want to have a view helper, so that i can call embed_video(embeddable, width, height)

So i have created the helper as a helper, and it works, but i would like to refactor it to use partials to make it cleaner, but i'm finding it hard to do this.

The helper:

module ViewHelpers
  def embed_video(embeddable, width, height)
    if embeddable.video_on_youtube?
      content_tag :iframe, nil, width: width, height: height,
        src: "//www.youtube.com/embed/#{embeddable.video_id}",
        allowfullscreen: true, frameborder: 0
    elsif embeddable.video_on_vimeo?
      content_tag :iframe, nil, width: width, height: height,
        src: "//player.vimeo.com/video/#{embeddable.video_id}",
        webkitallowfullscreen: true, mozallowfullscreen: true,
        allowfullscreen: true, frameborder: 0
    elsif embeddable.video_on_dailymotion?
      content_tag :iframe, nil, width: width, height: height,
        src: "//www.dailymotion.com/embed/video/#{embeddable.video_id}",
        webkitallowfullscreen: true, mozallowfullscreen: true,
        allowfullscreen: true, frameborder: 0
    elsif embeddable.video_on_veoh?
      %Q{
        <object width='#{width}' height='#{height}' id='veohFlashPlayer' name='veohFlashPlayer'>
          <param name='movie' value='http://www.veoh.com/swf/webplayer/WebPlayer.swf?version=AFrontend.5.7.0.1446&permalinkId=#{embeddable.video_id}&player=videodetailsembedded&videoAutoPlay=0&id=anonymous'></param>
          <param name='allowFullScreen' value='true'></param>
          <param name='allowscriptaccess' value='always'></param>
          <embed src='http://www.veoh.com/swf/webplayer/WebPlayer.swf?version=AFrontend.5.7.0.1446&permalinkId=#{embeddable.video_id}&player=videodetailsembedded&videoAutoPlay=0&id=anonymous' type='application/x-shockwave-flash' allowscriptaccess='always' allowfullscreen='true' width='#{width}' height='#{height}' id='veohFlashPlayerEmbed' name='veohFlashPlayerEmbed'>        </embed>
        </object>
      }.html_safe
    #
    # And more providers...
    #
  end
end

With the use of partials i want to write it like this:

module ViewHelpers
  def embed_video(embeddable, width, height)
    if embeddable.video_on_youtube?
      render 'youtube', embeddable: embeddable, width: width, height: height
    elsif embeddable.video_on_veoh?
      render 'veoh'#...etc
    end
  end
end

My attempted solution:

• Create a folder: lib/embeddable/partials

• Add partial for veoh: lib/embeddable/partials/_veoh.html.erb

Add view paths in railtie.rb

module Embeddable
  class Railtie < Rails::Railtie
    # ...load view helpers... #

    initializer 'embeddable.add_autoload_paths', :before => :set_autoload_paths do |app|
      app.config.autoload_paths << app.root.join("lib/embeddable/partials").to_s
    end

    # My attempt at adding the partials to the view path
    initializer 'embeddable.add_view_paths', :after => :add_view_paths do |app|
      ActiveSupport.on_load(:action_controller) do
        append_view_path app.root.join("lib/embeddable/").to_s
      end
    end
  end
end

When i try to render the view i get the following error:

ActionView::MissingTemplate: Missing partial partials/veoh with {:locale=>[:nb], :formats=>[:html], :handlers=>[:erb, :builder, :raw, :ruby, :coffee, :rabl, :haml]}. Searched in:
  * "/home/me/Arbeid/the_application/app/views"
  * "/home/me/.rvm/gems/ruby-2.1.0/gems/kaminari-0.15.1/app/views"
  * "/home/me/Arbeid/the_application/lib/embeddable"

Answer 1

After a lot of trail and error i managed to get it working. This is what i had to do:

I changed this:

initializer 'embeddable.add_view_paths', :after => :add_view_paths do |app|
  ActiveSupport.on_load(:action_controller) do
    append_view_path app.root.join("lib/embeddable/").to_s
  end
end

Into this:

initializer 'embeddable.add_view_paths', :after => :add_view_paths do |app|
  ActiveSupport.on_load(:action_controller) do
    append_view_path "#{Gem.loaded_specs['embeddable'].full_gem_path}/lib/embeddable"# <- this is the change
  end
end

Now i can render partials from the helper like this:

render 'partials/youtube', id: video_id, width: width, height: height

Answer 2

I know it's not a direct answer to your question but instead of reinventing a wheel I would rather propose using AutoHTML gem:

auto_html is a Rails extension for transforming URLs to appropriate resource (image, link, YouTube, Vimeo video,...). It's the perfect choice if you don't want to bother visitors with rich HTML editor or markup code, but you still want to allow them to embed video, images, links and more on your site, purely by pasting URL.

https://github.com/dejan/auto_html

To answer your question directly I think the problem is that you mixed up autoload path and view path.

You should have

app.config.autoload_paths << app.root.join("lib/embeddable").to_s

and

append_view_path app.root.join("lib/embeddable/partials").to_s