mirror of
https://github.com/rails/rails.git
synced 2022-11-09 12:12:34 -05:00
3ccea931fa
git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1914 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
89 lines
2.6 KiB
Ruby
89 lines
2.6 KiB
Ruby
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(*args, &block)
|
|
# execute the block
|
|
buffer = eval("_erbout", block.binding)
|
|
pos = buffer.length
|
|
block.call(*args)
|
|
|
|
# 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.
|
|
#
|
|
# NOTE: Beware that content_for is ignored in caches. So you shouldn't use it
|
|
# for elements that are going to be fragment cached.
|
|
def content_for(name, &block)
|
|
eval "@content_for_#{name} = (@content_for_#{name} || '') + capture(&block)"
|
|
end
|
|
end
|
|
end
|
|
end
|