Auto html

Rails plugin for transforming urls to appropriate resource (image, link, YouTube, Vimeo video,…). Check out the live demo.

Synopsis

auto_html plugin is 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.

Let’s say you have model Comment with attribute body. Create another column in table Comments called body_html. Now have something like this:

class Comment < ActiveRecord::Base
  auto_html_for :body do
    html_escape
    image
    youtube :width => 400, :height => 250
    link :target => "_blank", :rel => "nofollow"
    simple_format
  end
end

… and you’ll have this behaviour:

Comment.create(:body => 'Hey check out this cool video: http://www.youtube.com/watch?v=WdsGihou8J4')  
=> #<Comment id: 123, body: 'Hey check out this cool video: http://www.youtube.com/watch?v=WdsGihou8J4', body_html: '<p>Hey check out this cool video: <object height="250" width="400"><param name="movie" value="http://www.youtube.com/v/WdsGihou8J4" /><param name="wmode" value="transparent" /><embed src="http://www.youtube.com/v/WdsGihou8J4" type="application/x-shockwave-flash" height="250" wmode="transparent" width="400"></embed></object></p>'>

Note that order of invoking filters is important, ie. you want html_escape as first and link amongst last, so that it doesn’t transform youtube URL to plain link.

Now all you have to do is to display it in template without escaping, since plugin took care of that:

<% for comment in @comments %>
   <li><%= comment.body_html %></li>
<% end %>

If you need to display preview, no problem. Have something like this as action in your controller:

def preview
  comment = Comment.new(params[:comment])
  comment.auto_html_prepare
  render :text => comment.body_html
end

Plugin is highly customizable, and you can easily create new filters that will transform user input any way you like. For instance, this is the image filter that comes bundled with plugin:

AutoHtml.add_filter(:image) do |text|
  text.gsub(/http:\/\/.+\.(jpg|jpeg|bmp|gif|png)(\?\S+)?/i) do |match|
    %|<img src="#{match}" alt=""/>|
  end
end

Bundled filters

  • Big words - take big words in special tags

    big_words :length => 80, :tag => “span”

  • Dailymotion

    dailymotion :width => 480, :height => 360

  • Google video

    google_video :width => 650, :height => 391

  • HTML escaping

    html_escape

  • Image - replace image url to url with <a>

    image

  • Link - replace url to url with <a>

    link :target => “_blank”, :rel => “nofollow”

  • HTML White List Sanitizer

    sanitize

  • Simple format

    simple_format

  • Vimeo

    vimeo :width => 440, :height => 248, :show_title => false, :fullscreen => true, :show_byline => false, :show_portrait => false

  • Youtube

    youtube :width => 390, :height => 250

    youtube_js_api :width => 390, :height => 250

Install

gem 'auto_html', :git => 'git://github.com/galetahub/auto_html.git'

Credits

Author

Dejan Simic

Contributor

Claudio Perez Gamayo