Class: MicroQ::Middleware::Chain::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/micro_q/middleware/chain.rb

Direct Known Subclasses

Client, Server

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Base

Returns a new instance of Base.



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# File 'lib/micro_q/middleware/chain.rb', line 43

def initialize
  clear
end

Instance Method Details

#add(*items) ⇒ Object

Add any number of entries to the middleware chain



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# File 'lib/micro_q/middleware/chain.rb', line 54

def add(*items)
  @entries.concat(items.flatten).uniq!
end

#add_after(after, *items) ⇒ Object 



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# File 'lib/micro_q/middleware/chain.rb', line 63

def add_after(after, *items)
  remove(*items)
  @entries.insert(@entries.index(after)+1, *items).uniq! if items.any?
end

#add_before(before, *items) ⇒ Object 



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# File 'lib/micro_q/middleware/chain.rb', line 58

def add_before(before, *items)
  remove(*items)
  @entries.insert(@entries.index(before), *items).uniq! if items.any?
end

#call(*args, &block) ⇒ Object

Traverse the middleware chain by recursing until we reach the end of the chain and are able to invoke the given block. The block represents a message push (client) or a message invocation (server).

It is, however very generic and can be used as middleware around anything.



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# File 'lib/micro_q/middleware/chain.rb', line 88

def call(*args, &block)
  chain = (index = -1) && -> {
    (index += 1) == entries.length ?
      block.call : entries.at(index).new.call(*args, &chain)
  }

  chain.call
end

#clear ⇒ Object 



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# File 'lib/micro_q/middleware/chain.rb', line 77

def clear
  @entries = []
end

#entries ⇒ Object 



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# File 'lib/micro_q/middleware/chain.rb', line 47

def entries
  [*@entries, @last].compact
end

#remove(*items) ⇒ Object

Remove any number of entries from the middleware chain



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# File 'lib/micro_q/middleware/chain.rb', line 71

def remove(*items)
  @entries.tap do
    items.flatten.each {|item| @entries.delete(item) }
  end
end