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| -rw-r--r-- | actionpack/CHANGELOG | 2 | ||||
| -rw-r--r-- | actionpack/lib/action_view/helpers/capture_helper.rb | 95 |
2 files changed, 97 insertions, 0 deletions
diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG index e1e86d3e55..3470e0ae14 100644 --- a/actionpack/CHANGELOG +++ b/actionpack/CHANGELOG @@ -1,5 +1,7 @@ *SVN* +* Added CaptureHelper with CaptureHelper#capture and CaptureHelper#content_for. See documentation in helper #837 [Tobias Luetke] + * Fixed :anchor use in url_for #821 [Nicholas Seckar] * Removed the reliance on PATH_INFO as it was causing problems for caching and inhibited the new non-vhost support #822 [Nicholas Seckar] diff --git a/actionpack/lib/action_view/helpers/capture_helper.rb b/actionpack/lib/action_view/helpers/capture_helper.rb new file mode 100644 index 0000000000..aba4a85355 --- /dev/null +++ b/actionpack/lib/action_view/helpers/capture_helper.rb @@ -0,0 +1,95 @@ +module ActionView + module Helpers + # Capture lets you extract parts of code into instance variables which + # can be used in other points of the template or even layout file. + # + # == Capturing a block into an instance variable + # + # <% @script = capture do %> + # [some html...] + # <% end %> + # + # + # == Add javascript to header using content_for + # + # content_for("name") is a wrapper for capture which will store the + # fragment in a instance variable similar to @content_for_layout. + # + # layout.rhtml: + # + # <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> + # <head> + # <title>layout with js</title> + # <script type="text/javascript"> + # <%= @content_for_script %> + # </script> + # </head> + # <body> + # <%= @content_for_layout %> + # </body> + # </html> + # + # view.rhtml + # + # This page shows an alert box! + # + # <% content_for("script") do %> + # alert('hello world') + # <% end %> + # + # Normal view text + module CaptureHelper + # Capture allows you to extract a part of the template into an + # instance variable. You can use this instance variable anywhere + # in your templates and even in your layout. + # + # Example: + # + # <% @greeting = capture do %> + # Welcome To my shiny new web page! + # <% end %> + def capture(&block) + # execute the block + buffer = eval("_erbout", block.binding) + pos = buffer.length + block.call + + # extract the block + data = buffer[pos..-1] + + # replace it in the original with empty string + buffer[pos..-1] = '' + + data + end + + # Content_for will store the given block + # in an instance variable for later use in another template + # or in the layout. + # + # The name of the instance variable is content_for_<name> + # to stay consistent with @content_for_layout which is used + # by ActionView's layouts + # + # Example: + # + # <% content_for("header") do %> + # alert('hello world') + # <% end %> + # + # You can use @content_for_header anywhere in your templates + def content_for(name, &block) + base = controller.instance_variable_get(instance_var_name(name)) || "" + data = capture(&block) + controller.instance_variable_set(instance_var_name(name), base + data) + data + end + + private + + def instance_var_name(name) #:nodoc# + "@content_for_#{name}" + end + end + end +end |