Class: Peachy::Proxy

Inherits:
Object
  • Object
show all
Extended by:
MethodMask
Includes:
MorphIntoArray, MyMetaClass, XmlNode
Defined in:
lib/peachy/proxy.rb

Instance Method Summary collapse

Methods included from Compatibility

#version_safe_method_id

Constructor Details

#initialize(xml_node) ⇒ Proxy

Takes either a string containing XML or a Nokogiri::XML::Element as the single argument.



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# File 'lib/peachy/proxy.rb', line 13

def initialize xml_node
  @xml = xml_node if xml_node.kind_of? String
  @node = xml_node if xml_node.kind_of? Peachy::Parsers::ParserWrapper
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object

Overloaded so that calls to methods representative of an XML element or attribute can be generated dynamically.

For example, if a proxy is referenced in code as proxy.first_node, and first_node does match a child of the DOM encapsulated by proxy, then first_node will be generated on proxy.

However, if first_node does not represent a child in the underlying DOM then proxy will raise a NoMatchingXmlPart error.

The method name used to access an XML node has to follow the standard Ruby convention for method names, i.e. ^[a-z]+(?:_+)?0,$. If an attempt is made to call a method on a Peachy::Proxy that breaks this convention, Peachy will simply raise a MethodNotInRubyConvention error.

Collections are referenced as an array following the name of the individual items of the collection.

e.g. xml = <<XML <feed>

<items>
  <item>Story 1</item>
  <item>Story 2</item>
  <item>Story 3</item>
</items>

</feed> XML

@proxy.feed.items.item

> Story 1

@proxy.feed.items.item

> Story 3

Note that Peachy will try to manage the case where a single node is treated as the the first and only element in a collection. In this case, the pattern above will apply. Also, if an element is treated as a single child, but later treated as if it should be part of a collection, then an AlreadyASingleChild error will be raised. You can’t expect a node to be both a single child AND a single element in a collection.

Any calls to undefined methods that include arguments or a block will be deferred to the default implementation of method_missing.



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# File 'lib/peachy/proxy.rb', line 69

def method_missing method_name, *args, &block
  # check whether an Array method is called with arguments or a block
  return morph_into_array(clone, method_name, *args, &block) if used_as_array(method_name, block_given?, *args)

  # standard method_missing for any other call with arguments or a block
  super if args.any? or block_given?

  # try to create a method for the element
  child_proxy = generate_method_for_xml(MethodName.new(method_name))

  if !child_proxy.nil?
    # found a match, so mark as only child
    acts_as_only_child
    child_proxy
  elsif array_can?(method_name)
    # morph into an array, as method is a length one array call
    new_proxy = node.create_from_element
    morph_into_array(new_proxy, method_name)
  else
    no_matching_xml(method_name)
  end
end

Instance Method Details

#to_s ⇒ Object 



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# File 'lib/peachy/proxy.rb', line 18

def to_s
  return @xml unless @xml.nil?
  node.to_s
end