CKEditor is a library for WYSIWYG editor to be used inside web pages.

The ckeditor_rails gem integrates the CKEditor with the Rails asset pipeline.

And it would work with following environments:

• ruby 1.9.3+
• rails 3.0+

Include ckeditor_rails in Gemefile

gem 'ckeditor_rails'

Then run bundle install

Add to your app/assets/javascripts/application.js after //= require jquery_ujs to work with jQuery

//= require ckeditor-jquery

Add ckeditor class to text area tag

<%= f.text_area :content, :class => 'ckeditor' %>

$('.ckeditor').ckeditor({
  // optional config
});

Since version 4.1.3, non-digested assets of ckeditor-rails will simply be copied after digested assets were compiled.

Eric Anderson, thanks.

Add your app/assets/javascripts/ckeditor/config.js.coffee like

CKEDITOR.editorConfig = (config) ->
  config.language = "zh"
  config.uiColor = "#AADC6E"
  true

Type CKEDITOR.config in browser's console panel to check all configuration.

Add your config.js to assets precompile list in config/initializers/assets.rb.

Rails.application.config.assets.precompile += %w( ckeditor/config.js )

Add your app/assets/stylesheets/ckeditor/contents.css.scss like

body {
  font-size: 14px;
  color: gray;
  background-color: yellow;
}
ol,ul,dl {
  *margin-right:0px;
  padding:4 20px;
}

Add your contents.css to assets precompile list in config/initializers/assets.rb.

Rails.application.config.assets.precompile += %w( ckeditor/contents.css )

To avoid see warnings like

ckeditor.source.js:21 [CKEDITOR] Error code: exportpdf-no-token-url.
ckeditor.source.js:21 [CKEDITOR] For more information about this error go to https://ckeditor.com/docs/ckeditor4/latest/guide/dev_errors.html#exportpdf-no-token-url

Edit your app/assets/javascripts/ckeditor/config.js.coffee like

CKEDITOR.editorConfig = (config) ->
  config.removePlugins = 'exportpdf'
  true

Ref: https://ckeditor.com/cke4/addon/exportpdf

Install the plugin manually by copy to Rails asset pathes like

vendor/assets/images/ckeditor/plugins/exportpdf/icons
vendor/assets/javascripts/ckeditor/plugins/exportpdf/lang
vendor/assets/javascripts/ckeditor/plugins/exportpdf/plugin.js
vendor/assets/javascripts/ckeditor/plugins/exportpdf/LICENSE.md

Edit your app/assets/javascripts/ckeditor/config.js.coffee like

CKEDITOR.editorConfig = (config) ->
  # config.extraPlugins = 'exportpdf'
  config.exportPdf_tokenUrl = 'https://example.com/cs-token-endpoint'
  true

Ref: https://ckeditor.com/docs/ckeditor4/latest/features/exporttopdf.html#configuration

Add ckeditor_rails.rb to config/initializers/

Ckeditor::Rails.configure do |config|
  # default is nil for all languages, or set as %w[en zh]
  config.assets_languages = nil

  # default is nil for all plugins,
  # or set as white list: %w[image link liststyle table tabletools]
  # or set as black list: config.default_plugins - %w[about a11yhelp]
  config.assets_plugins = nil

  # default is nil for all skins, or set as %w[moono-lisa]
  config.assets_skins = nil

  # default is nil and it will be "#{::Sprockets::Railtie.config.assets.prefix}/ckeditor",
  # or set as String like '/assets/ckeditor',
  # or set as Proc / Lambda
  # no slash in the end
  config.assets_base_path = nil
end

It is important to keep these two the same.

• Ckeditor::Rails::AssetUrlProcessor will post process css url() attribute in all css files of ckeditor based on Ckeditor::Rails.assets_base_path.
• CKEDITOR_BASEPATH will be defined with Ckeditor::Rails.assets_base_path directly.

Edit your config/initializers/ckeditor_rails.rb like

Ckeditor::Rails.configure do |config|
  config.assets_base_path = Proc.new {
    base_path = ''
    if ENV['PROJECT'] =~ /editor/i
      base_path << "/#{Rails.root.basename.to_s}/"
    end
    base_path << Rails.application.config.assets.prefix
    base_path << '/ckeditor'
    base_path
  }
end

Note: if Rails.application.config.action_controller.relative_url_root is set, it will prepend to Ckeditor::Rails.assets_base_path automatically.

Maintain ckeditor_rails gem with Rake commands.

Update origin CKEditor source files.

rake update_ckeditor VERSION=4.19.0

Publish gem.

rake release

This is due to interference with Turbolinks -

The problem stems from the link itself so in order to resolve this issue you must disable turbolinks in the div containing the link pointing to where CKEditor is.

You can visit the Rails Turbolinks Repo for detailed documentation https://github.com/rails/turbolinks/#opting-out-of-turbolinks

Example

<div class="example" data-no-turbolink>
...
</div>

If you observe an issue (especially in Heroku environment) where asset compilation process skips JS and or CSS files, try adding the following line to app/environments/production.rb (or config file for the environment where you observe the issue):

config.assets.precompile += ['ckeditor/*']

Run bundle exec rake assets:precompile and ls -al public/assets/ckeditor/ to check if everything is generated as expected.

CKEditor use CKEditor license.

Other parts of gem use MIT license.