A simple and idiomatic way to pass multiple blocks to a method.

Add this line to your application's Gemfile:

gem 'bountiful_blocks', '~> 1.0'

And then execute:

$ bundle

Or you can install the gem on its own:

gem install bountiful_blocks

Bountiful Blocks allows you to pass multiple arbitrary blocks to a method:

def deliver message, &block
  mb = Multiblock(&block)
  
  ...
  
  if response.success?
    mb.on_success response.body
  else
    mb.on_error response.code
  end
end

deliver('Hello World!') do
  on_success do |body|
    puts body
  end
  
  on_error do |code|
    raise ClientError, code
  end
end

Kernel#Multiblock is a simple wrapper for BountifulBlocks::Multiblock.new.

You can provide names for required blocks, which will be checked on creation of the multiblock:

def deliver message, &block
  mb = Multiblock(:on_success, :on_error, &block)
  
  ...
  
  if response.success?
    mb.on_success response.body
  else
    mb.on_error response.code
  end
end

deliver('Hello World!') do
  on_success do |body|
    puts body
  end
end

# => Block required for on_error (ArgumentError)

Alternatively, you can check whether a block with a given name was provided with Multiblock#given?:

def deliver message, &block
  mb = Multiblock(:on_success, &block)
  
  ...
  
  if response.success?
    mb.on_success response.body
  elsif mb.given? :on_error
    mb.on_error response.code
  else
    'Fallback'
  end
end

Block names follow the same rules as method names, with the exception that they can't end in !, ?, or =.

To avoid conflicts, all utility method names will end in either !, ?, or =.

• raw! returns the value returned by the block, which can be useful to allow a block to work both as a regular block and a multiblock.
• given?(name) returns true if a block named name was provided.
• given! returns the names of all the provided blocks.
• given_blocks! returns all the provided blocks in a hash indexed by their names.
• call_all! returns a Hash that maps all block names to their results. You can provide arguments to call_all! and they will be forwarded in turn to all blocks. Notice that since multiblocks are frozen, call_all! can't cache the Hash and must create a new one on every invocation.

BountifulBlocks loosely follows Semantic Versioning, with a hard guarantee that breaking changes to the public API will always coincide with an increase to the MAJOR number.

Version numbers are in three parts: MAJOR.MINOR.PATCH.

• Breaking changes to the public API increment the MAJOR. There may also be changes that would otherwise increase the MINOR or the PATCH.
• Additions, deprecations, and "big" non breaking changes to the public API increment the MINOR. There may also be changes that would otherwise increase the PATCH.
• Bug fixes and "small" non breaking changes to the public API increment the PATCH.

Notice that any feature deprecated by a minor release can be expected to be removed by the next major release.

Full list of changes in CHANGELOG.md

Bug reports and pull requests are welcome on GitHub at https://github.com/moku-io/bountiful_blocks.

The gem is available as open source under the terms of the MIT License.