Asset Url Helper

仅得到 asset 所在的路径。

image_path & path_to_image
image_url  & url_to_image

javascript_path & path_to_javascript
javascript_url  & url_to_javascript

stylesheet_path & path_to_stylesheet
stylesheet_url  & url_to_stylesheet

video_path & path_to_video
video_url  & url_to_video

asset_path & path_to_asset
asset_url  & url_to_asset

audio_path & path_to_audio
audio_url  & url_to_audio

font_path & path_to_font
font_url  & url_to_font

compute_asset_extname
compute_asset_host
compute_asset_path