module Sinatra::Capture

Sinatra::Capture

Extension that enables blocks inside other extensions. It currently works for erb, slim and haml. Enables mixing of different template languages.

Example:

# in hello_world.erb

Say
<% a = capture do %>World<% end %>
Hello <%= a %>!

# in hello_world.slim

| Say
- a = capture do
  | World
|  Hello #{a}!

# in hello_world.haml

Say
- a = capture do
  World
  Hello #{a.strip}!

You can also use nested blocks.

Example

# in hello_world.erb

Say
<% a = capture do %>
  <% b = capture do %>World<% end %>
    <%= b %>!
<% end %>
Hello <%= a.strip %>

The main advantage of capture is mixing of different template engines.

Example

# in mix_me_up.slim

- two = capture do
  - erb "<%= 1 + 1 %>"
| 1 + 1 = #{two}

Usage

Classic Application

In a classic application simply require the helpers, and start using them:

require "sinatra"
require "sinatra/capture"

# The rest of your classic application code goes here...

Modular Application

In a modular application you need to require the helpers, and then tell the application you will use them:

require "sinatra/base"
require "sinatra/capture"

class MyApp < Sinatra::Base
  helpers Sinatra::Capture

  # The rest of your modular application code goes here...
end

Public Instance Methods

capture(*args, &block) click to toggle source
# File lib/sinatra/capture.rb, line 87
def capture(*args, &block)
  return block[*args] if ruby?
  if haml? && Tilt[:haml] == Tilt::HamlTemplate
    buffer = Haml::Buffer.new(nil, Haml::Options.new.for_buffer)
    with_haml_buffer(buffer) { capture_haml(*args, &block) }
  else
    @_out_buf, _buf_was = '', @_out_buf
    begin
      raw = block[*args]
      captured = block.binding.eval('@_out_buf')
      captured.empty? ? raw : captured
    ensure
      @_out_buf = _buf_was
    end
  end
end
capture_later(&block) click to toggle source
# File lib/sinatra/capture.rb, line 104
def capture_later(&block)
  engine = current_engine
  proc { |*a| with_engine(engine) { @capture = capture(*a, &block) } }
end