Object
Represents a collection of pipeline elements. Elements may be added to the pipeline, and then returned as a single object representing the chain of pipeline elements.
Add a new pipeline element to this collection. If the first parameter is a symbol or a string, it is taken to be the name of the element to add. If no explicit implementation is given, then the implementation is looked up in the :pipeline_elements service, using the given name.
After the first parameter, if the next parameter is numeric, it is taken to mean the priority of the element. This overrides whatever default priority is given for the selected element.
If the next parameter responds to the :new message, it is taken to be an explicit implementation of the element. This is only valid if a block is not given. If a block is given, then it is always taken to be the implementation of the element.
If the last parameter is a Hash, it is taken to be a map of options that should be passed to the element when it is instantiated.
This returns self, so that add calls may be chained.
# File lib/needle/pipeline/collection.rb, line 73 def add( *args, &block ) name = priority = nil options = {} klass = nil element = nil if [ Symbol, String ].any? { |i| args.first.is_a?( i ) } name = args.shift.to_s.intern end priority = args.shift if args.first.is_a?( Numeric ) klass = args.shift if args.first.respond_to?( :new ) && block.nil? options = args.shift if args.first.is_a?( Hash ) raise ArgumentError, "bad argument list #{args.inspect}" unless args.empty? if block element = BlockElement.new( @service_point, name, priority, options, block ) else klass ||= @service_point.container[:pipeline_elements].fetch( name ) element = klass.new( @service_point, name, priority, options ) end @elements << element self end
Builds a linked list of the elements, with the last element being the block (or block-like) object given by the parameter. Higher-priority elements will be closer to the head of the list.
# File lib/needle/pipeline/collection.rb, line 120 def chain_to( block ) head = tail = nil @elements.sort.reverse.each do |el| if head tail.succ = el tail = el else # first time through... head = tail = el end end if tail tail.succ = block return head else return block end end
Returns the first pipeline element with the given name, or nil if no such element exists.
# File lib/needle/pipeline/collection.rb, line 103 def get( name ) name = name.to_s.intern @elements.find { |el| name == el.name } end
Clears the state for each named element. If no elements are named, all elements are cleared.
# File lib/needle/pipeline/collection.rb, line 110 def reset!( *args ) @elements.each do |element| element.reset! if args.empty? || args.include?( element.name ) end self end
Generated with the Darkfish Rdoc Generator 2.