Class: Babylon::XmppParser

Inherits:
Nokogiri::XML::SAX::Document
  • Object
show all
Defined in:
lib/babylon/xmpp_parser.rb

Overview

This is the XML SAX Parser that accepts “pushed” content

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(callback) ⇒ XmppParser

Initialize the parser and adds the callback that will be called upon stanza completion



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# File 'lib/babylon/xmpp_parser.rb', line 11

def initialize(callback)
  @callback = callback
  @buffer = ""
  super()
  reset
end

Instance Attribute Details

#doc ⇒ Object

Returns the value of attribute doc.



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# File 'lib/babylon/xmpp_parser.rb', line 7

def doc
  @doc
end

#elem ⇒ Object

Returns the value of attribute elem.



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# File 'lib/babylon/xmpp_parser.rb', line 7

def elem
  @elem
end

#parser ⇒ Object

Returns the value of attribute parser.



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# File 'lib/babylon/xmpp_parser.rb', line 7

def parser
  @parser
end

Instance Method Details

#characters(string) ⇒ Object

Adds characters to the current element (being parsed)



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# File 'lib/babylon/xmpp_parser.rb', line 33

def characters(string)
  @buffer ||= ""
  @buffer += string 
end

#clear_characters_buffer ⇒ Object

Clears the characters buffer



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# File 'lib/babylon/xmpp_parser.rb', line 59

def clear_characters_buffer
  if @buffer && @elem
    @buffer.strip!
    @elem.add_child(Nokogiri::XML::Text.new(Babylon.decode_xml(@buffer), @doc)) unless @buffer.empty?
    @buffer = nil # empty the buffer
  end
end

#end_element(name) ⇒ Object

Terminates the current element and calls the callback



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# File 'lib/babylon/xmpp_parser.rb', line 69

def end_element(name)
  clear_characters_buffer
  if @elem
    if @elem.parent == @doc
      # If we're actually finishing the stanza (a stanza is always a document's root)
      @callback.call(@elem) 
      # We delete the current element and the doc (1 doc per stanza policy)
      @elem = @doc = nil 
    else
      @elem = @elem.parent 
    end 
  else 
    # Not sure what to do since it seems we're not processing any element at this time, so how can one end?
  end 
end

#push(data) ⇒ Object

Pushes the received data to the parser. The parser will then callback the document’s methods (start_tag, end_tag… etc)



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# File 'lib/babylon/xmpp_parser.rb', line 27

def push(data)
  @parser << data
end

#reset ⇒ Object

Resets the Pushed SAX Parser.



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# File 'lib/babylon/xmpp_parser.rb', line 20

def reset
  @parser = Nokogiri::XML::SAX::PushParser.new(self, "UTF-8")
  @elem = @doc = nil
end

#start_element(qname, attributes = []) ⇒ Object

Instantiate a new current Element, adds the corresponding attributes and namespaces. The new element is eventually added to a parent element (if present). If no element is being parsed, then, we create a new document, to which we add this new element as root. (we create one document per stanza to avoid memory problems)



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# File 'lib/babylon/xmpp_parser.rb', line 42

def start_element(qname, attributes = [])
  clear_characters_buffer
  @doc ||= Nokogiri::XML::Document.new
  @elem ||= @doc # If we have no current element, then, we take the doc
  @elem = @elem.add_child(Nokogiri::XML::Element.new(qname, @doc))
  add_namespaces_and_attributes_to_current_node(attributes)
  
  if @elem.name == "stream:stream"
    # We activate the callback since this element  will never end.
    @callback.call(@elem)
    @doc = @elem = nil # Let's prepare for the next stanza
    # And then, we start a new Sax Push Parser
  end
end