Class: Xap::XapMessage

Inherits:
Object
  • Object
show all
Defined in:
lib/xap/xap_msg.rb

Overview

Base class for all xAP message types. Registered subclasses must implement a parse method that accepts the message hash as its first parameter.

Direct Known Subclasses

XapHeartbeat, XapUnsupportedMessage

Constant Summary collapse

@@msgtypes = 
{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(msgclass, src_addr, src_uid, target_addr = nil) ⇒ XapMessage

msgclass - the message’s class src_addr - the message’s source address src_uid - the message’s source UID (TODO: merge with XapAddress?) target_addr - the message’s target address, or nil for no target



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# File 'lib/xap/xap_msg.rb', line 57

def initialize msgclass, src_addr, src_uid, target_addr = nil
	raise 'Do not instantiate XapMessage directly (use a subclass)' if self.class == XapMessage
	raise 'src_addr must be an XapAddress' unless src_addr.is_a? XapAddress
	raise 'target_addr must be nil or an XapAddress' unless target_addr.nil? || target_addr.is_a?(XapAddress)

	@src_addr = src_addr
	@target_addr = target_addr
	@version = 12
	@hop = 1
	@uid = src_uid
	@msgclass = msgclass
	@blocks = {}
	@headers = {}
end

Instance Attribute Details

#headername ⇒ Object

Returns the value of attribute headername.



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# File 'lib/xap/xap_msg.rb', line 10

def headername
  @headername
end

#hop ⇒ Object

Returns the value of attribute hop.



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# File 'lib/xap/xap_msg.rb', line 10

def hop
  @hop
end

#msgclass ⇒ Object

Returns the value of attribute msgclass.



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# File 'lib/xap/xap_msg.rb', line 10

def msgclass
  @msgclass
end

#src_addr ⇒ Object

Returns the value of attribute src_addr.



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# File 'lib/xap/xap_msg.rb', line 10

def src_addr
  @src_addr
end

#target_addr ⇒ Object

Returns the value of attribute target_addr.



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# File 'lib/xap/xap_msg.rb', line 10

def target_addr
  @target_addr
end

#uid ⇒ Object

Returns the value of attribute uid.



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# File 'lib/xap/xap_msg.rb', line 10

def uid
  @uid
end

#version ⇒ Object

Returns the value of attribute version.



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# File 'lib/xap/xap_msg.rb', line 10

def version
  @version
end

Class Method Details

.parse(data) ⇒ Object

Parses the given data as an xAP message. If the message type does not have a registered handler, an exception will be raised



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# File 'lib/xap/xap_msg.rb', line 14

def self.parse data
	raise 'data must be (convertible to) a String' unless data.respond_to? :to_s

	msghash = Xap::Parser::ParseXap.simple_parse data.to_s

	headername = msghash.keys[0].downcase
	raise "No handlers defined for #{headername} message headers." unless @@msgtypes[headername]

	classname = msghash[headername]['class']
	raise 'Message lacks a class field in its header.' unless classname || @@msgtypes[headername][nil]
	classname.downcase!

	handler = @@msgtypes[headername][classname] || @@msgtypes[headername][nil]
	raise "No handler defined for #{headername}/#{classname} messages." unless handler

	handler.parse msghash
end

.register_class(klass, msgclass, headername = 'xap-header') ⇒ Object

Registers the given klass as the handler for msgclass messages, with the header block called headername (‘xap-header’ by default).

Specify nil for msgclass to register a fallback handler for messages with the given header name that don’t have a specific class handler registered.



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# File 'lib/xap/xap_msg.rb', line 38

def self.register_class klass, msgclass, headername='xap-header'
	unless klass.is_a?(Class) && klass < XapMessage
		raise "klass must be a Class that inherits XapMessage, not #{klass.inspect}"
	end
	raise 'msgclass must be nil or a String' unless msgclass.nil? || msgclass.is_a?(String)

	Xap.log "Registered support for #{headername}/#{msgclass} messages via #{klass.name}"

	# TODO: Support regex for msgclass?
	headername.downcase!
	msgclass.downcase! if msgclass.is_a? String
	@@msgtypes[headername] = @@msgtypes[headername] || {}
	@@msgtypes[headername][msgclass] = klass
end

Instance Method Details

#to_s ⇒ Object

Returns a string representation of the message suitable for transmission on the network.



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# File 'lib/xap/xap_msg.rb', line 74

def to_s
	s = "#{headername}\n" +
		"{\n" +
		"v=#{@version}\n" +
	"hop=#{@hop}\n" +
	"uid=#{@uid}\n" +
	"class=#{@msgclass}\n" +
	"source=#{@src_addr}\n"

	s << "target=#{@target_addr}\n" if @target_addr

	if @headers
		@headers.each do |k, v|
			s << "#{k}=#{v}\n"
		end
	end

	s << "}\n"

	if @blocks
		@blocks.each do |name, block|
			s << "#{name}\n{\n"
			block.each do |k, v|
				s << "#{k}=#{v}\n"
			end
			s << "}\n"
		end
	end

	s
end

#uid_endpoint ⇒ Object

Returns the last two digits of the UID



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# File 'lib/xap/xap_msg.rb', line 107

def uid_endpoint
	@uid[-2, 2]
end