vendor/rails/activesupport/lib/active_support/xml_mini/rexml.rb

   1 # = XmlMini ReXML implementation
   2 module ActiveSupport
   3   module XmlMini_REXML #:nodoc:
   4     extend self
   5
   6     CONTENT_KEY = '__content__'.freeze
   7
   8     # Parse an XML Document string into a simple hash
   9     #
  10     # Same as XmlSimple::xml_in but doesn't shoot itself in the foot,
  11     # and uses the defaults from ActiveSupport
  12     #
  13     # string::
  14     #   XML Document string to parse
  15     def parse(string)
  16       require 'rexml/document' unless defined?(REXML::Document)
  17       doc = REXML::Document.new(string)
  18       merge_element!({}, doc.root)
  19     end
  20
  21     private
  22       # Convert an XML element and merge into the hash
  23       #
  24       # hash::
  25       #   Hash to merge the converted element into.
  26       # element::
  27       #   XML element to merge into hash
  28       def merge_element!(hash, element)
  29         merge!(hash, element.name, collapse(element))
  30       end
  31
  32       # Actually converts an XML document element into a data structure.
  33       #
  34       # element::
  35       #   The document element to be collapsed.
  36       def collapse(element)
  37         hash = get_attributes(element)
  38
  39         if element.has_elements?
  40           element.each_element {|child| merge_element!(hash, child) }
  41           merge_texts!(hash, element) unless empty_content?(element)
  42           hash
  43         else
  44           merge_texts!(hash, element)
  45         end
  46       end
  47
  48       # Merge all the texts of an element into the hash
  49       #
  50       # hash::
  51       #   Hash to add the converted emement to.
  52       # element::
  53       #   XML element whose texts are to me merged into the hash
  54       def merge_texts!(hash, element)
  55         unless element.has_text?
  56           hash
  57         else
  58           # must use value to prevent double-escaping
  59           merge!(hash, CONTENT_KEY, element.texts.sum(&:value))
  60         end
  61       end
  62
  63       # Adds a new key/value pair to an existing Hash. If the key to be added
  64       # already exists and the existing value associated with key is not
  65       # an Array, it will be wrapped in an Array. Then the new value is
  66       # appended to that Array.
  67       #
  68       # hash::
  69       #   Hash to add key/value pair to.
  70       # key::
  71       #   Key to be added.
  72       # value::
  73       #   Value to be associated with key.
  74       def merge!(hash, key, value)
  75         if hash.has_key?(key)
  76           if hash[key].instance_of?(Array)
  77             hash[key] << value
  78           else
  79             hash[key] = [hash[key], value]
  80           end
  81         elsif value.instance_of?(Array)
  82           hash[key] = [value]
  83         else
  84           hash[key] = value
  85         end
  86         hash
  87       end
  88
  89       # Converts the attributes array of an XML element into a hash.
  90       # Returns an empty Hash if node has no attributes.
  91       #
  92       # element::
  93       #   XML element to extract attributes from.
  94       def get_attributes(element)
  95         attributes = {}
  96         element.attributes.each { |n,v| attributes[n] = v }
  97         attributes
  98       end
  99
 100       # Determines if a document element has text content
 101       #
 102       # element::
 103       #   XML element to be checked.
 104       def empty_content?(element)
 105         element.texts.join.blank?
 106       end
 107   end
 108 end