Ruby on Rails Asset Tag Helpers

翻譯並摘自http://guides.rubyonrails.org/layouts_and_rendering.html

Asset tag helpers provide methods for generating HTML that link views to feeds, JavaScript, stylesheets, images, videos and audios. 

1. auto_discovery_link_tag
2. javascript_include_tag
3. stylesheet_link_tag
4. image_tag
5. video_tag
6. audio_tag 

javascript_include_tag 

早期的Rails，js目錄在public/javascripts目錄，使用了Asset Pipeline以後，js目錄在/assets/javascripts。

 <%= javascript_include_tag "main" %>

rails輸出爲

<script src='/public/javascripts/main.js'></script>

注:若是是Asset Pipeline，rails輸出則爲<script src='/assets/javascripts/main.js'></script>

<%= javascript_include_tag "main", "columns" %>

輸出爲

<script src='/public/javascripts/main.js'></script>
<script src='/public/javascripts/columns.js'></script>

stylesheet_link_tag與javascript_include_tag 相似，再也不贅述