Module: Roda::RodaPlugins::Chunked::InstanceMethods

Defined in:
lib/roda/plugins/chunked.rb

Instance Method Summary collapse

Instance Method Details

#chunked(template, opts = OPTS, &block) ⇒ Object

Render a response to the user in chunks. See Chunked for an overview. If a block is given, it is passed to #delay.



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# File 'lib/roda/plugins/chunked.rb', line 206

def chunked(template, opts=OPTS, &block)
  unless defined?(@_chunked)
    @_chunked = env['HTTP_VERSION'] == "HTTP/1.1"
  end

  if block
    delay(&block)
  end

  unless @_chunked
    # If chunking is disabled, do a normal rendering of the view.
    run_delayed_blocks
    return view(template, opts)
  end

  if template.is_a?(Hash)
    if opts.empty?
      opts = template
    else
      opts = Hash[opts].merge!(template)
    end
  end
  
  # Hack so that the arguments don't need to be passed
  # through the response and body objects.
  @_each_chunk_args = [template, opts]

  res = response
  headers = res.headers
  if chunk_headers = self.opts[:chunk_headers]
    headers.merge!(chunk_headers)
  end
  headers['Transfer-Encoding'] = 'chunked'

  throw :halt, res.finish_with_body(Body.new(self))
end

#delay(&block) ⇒ Object

Delay the execution of the block until right before the content template is to be rendered.

Raises:



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# File 'lib/roda/plugins/chunked.rb', line 245

def delay(&block)
  raise RodaError, "must pass a block to Roda#delay" unless block
  (@_delays ||= []) << block
end

#each_chunk ⇒ Object

Yield each chunk of the template rendering separately.



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# File 'lib/roda/plugins/chunked.rb', line 251

def each_chunk
  response.body.each{|s| yield s}

  template, opts = @_each_chunk_args

  # Use a lambda for the flusher, so that a call to flush
  # by a template can result in this method yielding a chunk
  # of the response.
  @_flusher = lambda do
    yield @_out_buf
    @_out_buf = String.new
  end

  if layout_opts  = view_layout_opts(opts)
    @_out_buf = render_template(layout_opts) do
      flush
      run_delayed_blocks
      yield opts[:content] || render_template(template, opts)
      nil
    end
  else
    run_delayed_blocks
    yield view(template, opts)
  end

  flush
rescue => e
  handle_chunk_error(e)
end

#flush ⇒ Object

Call the flusher if one is defined. If one is not defined, this is a no-op, so flush can be used inside views without breaking things if chunking is not used.



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# File 'lib/roda/plugins/chunked.rb', line 289

def flush
  @_flusher.call if @_flusher
end

#handle_chunk_error(e) ⇒ Object

By default, raise the exception.



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# File 'lib/roda/plugins/chunked.rb', line 282

def handle_chunk_error(e)
  raise e
end

#no_chunk! ⇒ Object

Disable chunking for the current request. Mostly useful when chunking is turned on by default.



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# File 'lib/roda/plugins/chunked.rb', line 190

def no_chunk!
  @_chunked = false
end

#view(*a) ⇒ Object

If chunking by default, call chunked if it hasn’t yet been called and chunking is not specifically disabled.



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# File 'lib/roda/plugins/chunked.rb', line 196

def view(*a)
  if opts[:chunk_by_default] && !defined?(@_chunked)
    chunked(*a)
  else
    super
  end
end