Class: XML::Mapping::HashNode

Inherits:
SubObjectBaseNode show all
Defined in:
lib/xml/mapping/standard_nodes.rb

Overview

Node factory function synopsis:

hash_node :_attrname_, _per_hashelement_path_, _key_path_
                  [, :default_value=>_obj_]
                  [, :optional=>true]
                  [, :class=>_c_]
                  [, :marshaller=>_proc_]
                  [, :unmarshaller=>_proc_]
                  [, :mapping=>_m_]
                  [, :sub_mapping=>_sm_]

  • or -

    hash_node :attrname, base_path, per_hashelement_path, key_path

    [keyword args the same]

Node that maps a sequence of sub-nodes of the XML tree to an attribute containing a hash of Ruby objects, with each hash value mapping to a corresponding member of the sequence of sub-nodes. The (string-valued) hash key associated with a hash value v is mapped to the text of a specific sub-node of v’s sub-node.

Analogously to ArrayNode, base_path and per_arrelement_path define the XPath expression that “yields” the sequence of XML nodes, each of which maps to a value in the hash table. Relative to such a node, key_path_ names the node whose text becomes the associated hash key.

Instance Method Summary collapse

Methods inherited from SingleAttributeNode

#default_when_xpath_err, #initialize_impl, #is_present_in?, #obj_initializing, #obj_to_xml, #xml_to_obj

Methods inherited from Node

#is_present_in?, #obj_initializing, #obj_to_xml, #xml_to_obj

Constructor Details

#initialize(*args) ⇒ HashNode

Initializer. Called with keyword arguments and either 2 or 3 paths; the hindmost path argument passed is delegated to key_path, the preceding path argument is delegated to per_arrelement_path, the path preceding that argument (if present, “” by default) is delegated to base_path. The meaning of the keyword arguments is the same as for ObjectNode.



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# File 'lib/xml/mapping/standard_nodes.rb', line 335

def initialize(*args)
  path1,path2,path3,*args = super(*args)
  base_path,per_hashelement_path,key_path = if path3
                                              [path1,path2,path3]
                                            else
                                              ["",path1,path2]
                                            end
  per_hashelement_path=per_hashelement_path[1..-1] if per_hashelement_path[0]==?/
  @base_path = XML::XXPath.new(base_path)
  @per_hashelement_path = XML::XXPath.new(per_hashelement_path)
  @key_path = XML::XXPath.new(key_path)
  @reader_path = XML::XXPath.new(base_path+"/"+per_hashelement_path)
  args
end

Instance Method Details

#extract_attr_value(xml) ⇒ Object

:nodoc:



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# File 'lib/xml/mapping/standard_nodes.rb', line 349

def extract_attr_value(xml) # :nodoc:
  result = {}
  default_when_xpath_err{@reader_path.all(xml)}.each do |elt|
    key = @key_path.first(elt).text
    value = @unmarshaller.call(elt)
    result[key] = value
  end
  result
end

#set_attr_value(xml, value) ⇒ Object

:nodoc:



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# File 'lib/xml/mapping/standard_nodes.rb', line 358

def set_attr_value(xml, value) # :nodoc:
  base_elt = @base_path.first(xml,:ensure_created=>true)
  value.each_pair do |k,v|
    elt = @per_hashelement_path.create_new(base_elt)
    @marshaller.call(elt,v)
    @key_path.first(elt,:ensure_created=>true).text = k
  end
end