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Diffstat (limited to 'actionpack/lib/action_view/helpers/capture_helper.rb')
| -rw-r--r-- | actionpack/lib/action_view/helpers/capture_helper.rb | 216 |
1 files changed, 0 insertions, 216 deletions
diff --git a/actionpack/lib/action_view/helpers/capture_helper.rb b/actionpack/lib/action_view/helpers/capture_helper.rb deleted file mode 100644 index 5afe435459..0000000000 --- a/actionpack/lib/action_view/helpers/capture_helper.rb +++ /dev/null @@ -1,216 +0,0 @@ -require 'active_support/core_ext/string/output_safety' - -module ActionView - # = Action View Capture Helper - module Helpers - # CaptureHelper exposes methods to let you extract generated markup which - # can be used in other parts of a template or layout file. - # - # It provides a method to capture blocks into variables through capture and - # a way to capture a block of markup for use in a layout through content_for. - module CaptureHelper - # The capture method allows you to extract part of a template into a - # variable. You can then use this variable anywhere in your templates or layout. - # - # The capture method can be used in ERB templates... - # - # <% @greeting = capture do %> - # Welcome to my shiny new web page! The date and time is - # <%= Time.now %> - # <% end %> - # - # ...and Builder (RXML) templates. - # - # @timestamp = capture do - # "The current timestamp is #{Time.now}." - # end - # - # You can then use that variable anywhere else. For example: - # - # <html> - # <head><title><%= @greeting %></title></head> - # <body> - # <b><%= @greeting %></b> - # </body></html> - # - def capture(*args) - value = nil - buffer = with_output_buffer { value = yield(*args) } - if string = buffer.presence || value and string.is_a?(String) - ERB::Util.html_escape string - end - end - - # Calling content_for stores a block of markup in an identifier for later use. - # In order to access this stored content in other templates, helper modules - # or the layout, you would pass the identifier as an argument to <tt>content_for</tt>. - # - # Note: <tt>yield</tt> can still be used to retrieve the stored content, but calling - # <tt>yield</tt> doesn't work in helper modules, while <tt>content_for</tt> does. - # - # <% content_for :not_authorized do %> - # alert('You are not authorized to do that!') - # <% end %> - # - # You can then use <tt>content_for :not_authorized</tt> anywhere in your templates. - # - # <%= content_for :not_authorized if current_user.nil? %> - # - # This is equivalent to: - # - # <%= yield :not_authorized if current_user.nil? %> - # - # <tt>content_for</tt>, however, can also be used in helper modules. - # - # module StorageHelper - # def stored_content - # content_for(:storage) || "Your storage is empty" - # end - # end - # - # This helper works just like normal helpers. - # - # <%= stored_content %> - # - # You can also use the <tt>yield</tt> syntax alongside an existing call to - # <tt>yield</tt> in a layout. For example: - # - # <%# This is the layout %> - # <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> - # <head> - # <title>My Website</title> - # <%= yield :script %> - # </head> - # <body> - # <%= yield %> - # </body> - # </html> - # - # And now, we'll create a view that has a <tt>content_for</tt> call that - # creates the <tt>script</tt> identifier. - # - # <%# This is our view %> - # Please login! - # - # <% content_for :script do %> - # <script>alert('You are not authorized to view this page!')</script> - # <% end %> - # - # Then, in another view, you could to do something like this: - # - # <%= link_to 'Logout', action: 'logout', remote: true %> - # - # <% content_for :script do %> - # <%= javascript_include_tag :defaults %> - # <% end %> - # - # That will place +script+ tags for your default set of JavaScript files on the page; - # this technique is useful if you'll only be using these scripts in a few views. - # - # Note that content_for concatenates (default) the blocks it is given for a particular - # identifier in order. For example: - # - # <% content_for :navigation do %> - # <li><%= link_to 'Home', action: 'index' %></li> - # <% end %> - # - # And in other place: - # - # <% content_for :navigation do %> - # <li><%= link_to 'Login', action: 'login' %></li> - # <% end %> - # - # Then, in another template or layout, this code would render both links in order: - # - # <ul><%= content_for :navigation %></ul> - # - # If the flush parameter is true content_for replaces the blocks it is given. For example: - # - # <% content_for :navigation do %> - # <li><%= link_to 'Home', action: 'index' %></li> - # <% end %> - # - # <%# Add some other content, or use a different template: %> - # - # <% content_for :navigation, flush: true do %> - # <li><%= link_to 'Login', action: 'login' %></li> - # <% end %> - # - # Then, in another template or layout, this code would render only the last link: - # - # <ul><%= content_for :navigation %></ul> - # - # Lastly, simple content can be passed as a parameter: - # - # <% content_for :script, javascript_include_tag(:defaults) %> - # - # WARNING: content_for is ignored in caches. So you shouldn't use it for elements that will be fragment cached. - def content_for(name, content = nil, options = {}, &block) - if content || block_given? - if block_given? - options = content if content - content = capture(&block) - end - if content - options[:flush] ? @view_flow.set(name, content) : @view_flow.append(name, content) - end - nil - else - @view_flow.get(name).presence - end - end - - # The same as +content_for+ but when used with streaming flushes - # straight back to the layout. In other words, if you want to - # concatenate several times to the same buffer when rendering a given - # template, you should use +content_for+, if not, use +provide+ to tell - # the layout to stop looking for more contents. - def provide(name, content = nil, &block) - content = capture(&block) if block_given? - result = @view_flow.append!(name, content) if content - result unless content - end - - # content_for? checks whether any content has been captured yet using `content_for`. - # Useful to render parts of your layout differently based on what is in your views. - # - # <%# This is the layout %> - # <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> - # <head> - # <title>My Website</title> - # <%= yield :script %> - # </head> - # <body class="<%= content_for?(:right_col) ? 'two-column' : 'one-column' %>"> - # <%= yield %> - # <%= yield :right_col %> - # </body> - # </html> - def content_for?(name) - @view_flow.get(name).present? - end - - # Use an alternate output buffer for the duration of the block. - # Defaults to a new empty string. - def with_output_buffer(buf = nil) #:nodoc: - unless buf - buf = ActionView::OutputBuffer.new - buf.force_encoding(output_buffer.encoding) if output_buffer - end - self.output_buffer, old_buffer = buf, output_buffer - yield - output_buffer - ensure - self.output_buffer = old_buffer - end - - # Add the output buffer to the response body and start a new one. - def flush_output_buffer #:nodoc: - if output_buffer && !output_buffer.empty? - response.stream.write output_buffer - self.output_buffer = output_buffer.respond_to?(:clone_empty) ? output_buffer.clone_empty : output_buffer[0, 0] - nil - end - end - end - end -end |