Returns a link tag that browsers and news readers can use to auto-detect a RSS or ATOM feed for this page. The type can either be :rss (default) or :atom and the options follow the url_for style of declaring a link target.

Examples:

  auto_discovery_link_tag # =>
    <link rel="alternate" type="application/rss+xml" title="RSS" href="http://www.curenthost.com/controller/action" />
  auto_discovery_link_tag(:atom) # =>
    <link rel="alternate" type="application/atom+xml" title="ATOM" href="http://www.curenthost.com/controller/action" />
  auto_discovery_link_tag(:rss, {:action => "feed"}) # =>
    <link rel="alternate" type="application/rss+xml" title="RSS" href="http://www.curenthost.com/controller/feed" />
  auto_discovery_link_tag(:rss, {:action => "feed"}, {:title => "My RSS"}) # =>
    <link rel="alternate" type="application/rss+xml" title="My RSS" href="http://www.curenthost.com/controller/feed" />

[Source]

    # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 21
21:       def auto_discovery_link_tag(type = :rss, options = {}, tag_options = {})
22:         tag(
23:           "link", 
24:           "rel" => tag_options[:rel] || "alternate",
25:           "type" => tag_options[:type] || "application/#{type}+xml",
26:           "title" => tag_options[:title] || type.to_s.upcase,
27:           "href" => url_for(options.merge(:only_path => false))
28:         )
29:       end

Returns path to an image asset. Example:

The src can be supplied as a…

• full path, like "/my_images/image.gif"
• file name, like "rss.gif", that gets expanded to "/images/rss.gif"
• file name without extension, like "logo", that gets expanded to "/images/logo.png"

[Source]

    # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 93
93:       def image_path(source)
94:         compute_public_path(source, 'images', 'png')
95:       end

Returns an image tag converting the options instead html options on the tag, but with these special cases:

• :alt - If no alt text is given, the file name part of the src is used (capitalized and without the extension)
• :size - Supplied as "XxY", so "30x45" becomes width="30" and height="45"

The src can be supplied as a…

• full path, like "/my_images/image.gif"
• file name, like "rss.gif", that gets expanded to "/images/rss.gif"
• file name without extension, like "logo", that gets expanded to "/images/logo.png"

[Source]

     # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 106
106:       def image_tag(source, options = {})
107:         options.symbolize_keys
108:                 
109:         options[:src] = image_path(source)
110:         options[:alt] ||= File.basename(options[:src], '.*').split('.').first.capitalize
111:         
112:         if options[:size]
113:           options[:width], options[:height] = options[:size].split("x")
114:           options.delete :size
115:         end
116: 
117:         tag("img", options)
118:       end

Returns a script include tag per source given as argument. Examples:

  javascript_include_tag "xmlhr" # =>
    <script type="text/javascript" src="/javascripts/xmlhr.js"></script>

  javascript_include_tag "common.javascript", "/elsewhere/cools" # =>
    <script type="text/javascript" src="/javascripts/common.javascript"></script>
    <script type="text/javascript" src="/elsewhere/cools.js"></script>

  javascript_include_tag :defaults # =>
    <script type="text/javascript" src="/javascripts/prototype.js"></script>
    <script type="text/javascript" src="/javascripts/effects.js"></script>
    <script type="text/javascript" src="/javascripts/controls.js"></script>
    <script type="text/javascript" src="/javascripts/dragdrop.js"></script>

[Source]

    # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 52
52:       def javascript_include_tag(*sources)
53:         options = sources.last.is_a?(Hash) ? sources.pop.stringify_keys : { }
54:         sources = ['prototype', 'effects', 'controls', 'dragdrop'] if sources.first == :defaults
55:         sources.collect { |source|
56:           source = javascript_path(source)        
57:           content_tag("script", "", { "type" => "text/javascript", "src" => source }.merge(options))
58:         }.join("\n")
59:       end

Returns path to a javascript asset. Example:

  javascript_path "xmlhr" # => /javascripts/xmlhr.js

[Source]

    # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 34
34:       def javascript_path(source)
35:         compute_public_path(source, 'javascripts', 'js')        
36:       end

Returns a css link tag per source given as argument. Examples:

  stylesheet_link_tag "style" # =>
    <link href="/stylesheets/style.css" media="screen" rel="Stylesheet" type="text/css" />

  stylesheet_link_tag "style", :media => "all" # =>
    <link href="/stylesheets/style.css" media="all" rel="Stylesheet" type="text/css" />

  stylesheet_link_tag "random.styles", "/css/stylish" # =>
    <link href="/stylesheets/random.styles" media="screen" rel="Stylesheet" type="text/css" />
    <link href="/css/stylish.css" media="screen" rel="Stylesheet" type="text/css" />

[Source]

    # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 79
79:       def stylesheet_link_tag(*sources)
80:         options = sources.last.is_a?(Hash) ? sources.pop.stringify_keys : { }
81:         sources.collect { |source|
82:           source = stylesheet_path(source)
83:           tag("link", { "rel" => "Stylesheet", "type" => "text/css", "media" => "screen", "href" => source }.merge(options))
84:         }.join("\n")
85:       end

Returns path to a stylesheet asset. Example:

  stylesheet_path "style" # => /stylesheets/style.css

[Source]

    # File vendor/rails/actionpack/lib/action_view/helpers/asset_tag_helper.rb, line 64
64:       def stylesheet_path(source)
65:         compute_public_path(source, 'stylesheets', 'css')
66:       end