Class: ZipKit::BlockWrite

Inherits:
Object
  • Object
show all
Includes:
WriteShovel
Defined in:
lib/zip_kit/block_write.rb

Overview

Acts as a converter between callers which send data to the #<< method (such as all the ZipKit writer methods, which push onto anything), and a given block. Every time #<< gets called on the BlockWrite, the block given to the constructor will be called with the same argument. ZipKit uses this object when integrating with Rack and in the OutputEnumerator. Normally you wouldn't need to use it manually but you always can. BlockWrite will also ensure the binary string encoding is forced onto any string that passes through it.

For example, you can create a Rack response body like so:

class MyRackResponse
  def each
    writer = ZipKit::BlockWrite.new {|chunk| yield(chunk) }
    writer << "Hello" << "world" << "!"
  end
end
[200, {}, MyRackResponse.new]

Instance Method Summary collapse

Methods included from WriteShovel

#write

Constructor Details

#initialize(&block) {|bytes| ... } ⇒ BlockWrite

Creates a new BlockWrite.

Parameters:

  • block —

    The block that will be called when this object receives the << message

Yield Parameters:

  • bytes (String) —

    A string in binary encoding which has just been written into the object



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# File 'lib/zip_kit/block_write.rb', line 26

def initialize(&block)
  @block = block
end

Instance Method Details

#<<(buf) ⇒ ZipKit::BlockWrite

Sends a string through to the block stored in the BlockWrite.

Parameters:

  • buf (String) —

    the string to write. Note that a zero-length String will not be forwarded to the block, as it has special meaning when used with chunked encoding (it indicates the end of the stream).

Returns:



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# File 'lib/zip_kit/block_write.rb', line 43

def <<(buf)
  # Zero-size output has a special meaning  when using chunked encoding
  return if buf.nil? || buf.bytesize.zero?

  @block.call(buf.b)
  self
end