Module: HappyMapper::ClassMethods

Defined in:
lib/happymapper.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#nokogiri_config_callbackProc (readonly)

The callback defined through #with_nokogiri_config.

Returns:

  • (Proc)

    the proc to pass to Nokogiri to setup parse options. nil if empty.


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# File 'lib/happymapper.rb', line 271

def nokogiri_config_callback
  @nokogiri_config_callback
end

Instance Method Details

#after_parse {|object| ... } ⇒ Object

Register a new after_parse callback, given as a block.

Yields:

  • (object)

    Yields the newly-parsed object to the block after parsing. Sub-objects will be already populated.


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# File 'lib/happymapper.rb', line 201

def after_parse(&block)
  after_parse_callbacks.push(block)
end

#after_parse_callbacksObject

The list of registered after_parse callbacks.


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# File 'lib/happymapper.rb', line 192

def after_parse_callbacks
  @after_parse_callbacks ||= []
end

#attribute(name, type, options = {}) ⇒ Object

The xml has the following attributes defined.

Examples:


"<country code='de'>Germany</country>"

# definition of the 'code' attribute within the class
attribute :code, String

Parameters:

  • name (Symbol)

    the name of the accessor that is created

  • type (String, Class)

    the class name of the name of the class whcih the object will be converted upon parsing

  • options (Hash) (defaults to: {})

    additional parameters to send to the relationship


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# File 'lib/happymapper.rb', line 57

def attribute(name, type, options = {})
  attribute = Attribute.new(name, type, options)
  @attributes[name] = attribute
  attr_accessor attribute.method_name.intern
end

#attributesArray<Attribute>

The elements defined through #attribute.

Returns:

  • (Array<Attribute>)

    a list of the attributes defined for this class; an empty array is returned when there have been no attributes defined.


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# File 'lib/happymapper.rb', line 69

def attributes
  @attributes.values
end

#content(name, type = String, options = {}) ⇒ Object

The value stored in the text node of the current element.

Examples:


"<firstName>Michael Jackson</firstName>"

# definition of the 'firstName' text node within the class

content :first_name, String

Parameters:

  • name (Symbol)

    the name of the accessor that is created

  • type (String, Class) (defaults to: String)

    the class name of the name of the class whcih the object will be converted upon parsing. By Default String class will be taken.

  • options (Hash) (defaults to: {})

    additional parameters to send to the relationship


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# File 'lib/happymapper.rb', line 145

def content(name, type = String, options = {})
  @content = TextNode.new(name, type, options)
  attr_accessor @content.method_name.intern
end

#defined_contentObject


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# File 'lib/happymapper.rb', line 387

def defined_content
  @content if defined? @content
end

#element(name, type, options = {}) ⇒ Object

An element defined in the XML that is parsed.

Examples:


"<address location='home'>
   <city>Oldenburg</city>
 </address>"

# definition of the 'city' element within the class

element :city, String

Parameters:

  • name (Symbol)

    the name of the accessor that is created

  • type (String, Class)

    the class name of the name of the class whcih the object will be converted upon parsing

  • options (Hash) (defaults to: {})

    additional parameters to send to the relationship


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# File 'lib/happymapper.rb', line 112

def element(name, type, options = {})
  element = Element.new(name, type, options)
  attr_accessor element.method_name.intern unless @elements[name]
  @elements[name] = element
end

#elementsArray<Element>

The elements defined through #element, #has_one, and #has_many.

Returns:

  • (Array<Element>)

    a list of the elements contained defined for this class; an empty array is returned when there have been no elements defined.


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# File 'lib/happymapper.rb', line 125

def elements
  @elements.values
end

#has_many(name, type, options = {}) ⇒ Object

The object has many of these elements in the XML.

Parameters:

  • name (Symbol)

    the name of accessor that is created

  • type (String, Class)

    the class name or the name of the class which the object will be converted upon parsing.

  • options (Hash) (defaults to: {})

    additional parameters to send to the relationship

See Also:


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# File 'lib/happymapper.rb', line 185

def has_many(name, type, options = {})
  element name, type, { single: false }.merge(options)
end

#has_one(name, type, options = {}) ⇒ Object

The object has one of these elements in the XML. If there are multiple, the last one will be set to this value.

Parameters:

  • name (Symbol)

    the name of the accessor that is created

  • type (String, Class)

    the class name of the name of the class whcih the object will be converted upon parsing

  • options (Hash) (defaults to: {})

    additional parameters to send to the relationship

See Also:


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# File 'lib/happymapper.rb', line 171

def has_one(name, type, options = {})
  element name, type, { single: true }.merge(options)
end

#has_xml_contentObject

Sets the object to have xml content, this will assign the XML contents that are parsed to the attribute accessor xml_content. The object will respond to the method #xml_content and will return the XML data that it has parsed.


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# File 'lib/happymapper.rb', line 156

def has_xml_content
  attr_accessor :xml_content
end

#namespace(namespace = nil) ⇒ Object

Specify a namespace if a node and all its children are all namespaced elements. This is simpler than passing the :namespace option to each defined element.

Parameters:

  • namespace (String) (defaults to: nil)

    the namespace to set as default for the class element.


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# File 'lib/happymapper.rb', line 213

def namespace(namespace = nil)
  @namespace = namespace if namespace
  @namespace if defined? @namespace
end

#parse(xml, options = {}) ⇒ Object

Parameters:

  • xml (Nokogiri::XML::Node, Nokogiri:XML::Document, String)

    the XML contents to convert into Object.

  • options (Hash) (defaults to: {})

    additional information for parsing. :single => true if requesting a single object, otherwise it defaults to retuning an array of multiple items. :xpath information where to start the parsing :namespace is the namespace to use for additional information.


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# File 'lib/happymapper.rb', line 293

def parse(xml, options = {})
  # Capture any provided namespaces and merge in any namespaces that have
  # been registered on the object.
  namespaces = options[:namespaces] || {}
  namespaces = namespaces.merge(@registered_namespaces)

  # If the XML specified is an Node then we have what we need.
  if xml.is_a?(Nokogiri::XML::Node) && !xml.is_a?(Nokogiri::XML::Document)
    node = xml
  else

    unless xml.is_a?(Nokogiri::XML::Document)
      # Attempt to parse the xml value with Nokogiri XML as a document
      # and select the root element
      xml = Nokogiri::XML(
        xml, nil, nil,
        Nokogiri::XML::ParseOptions::STRICT,
        &nokogiri_config_callback
      )
    end
    # Now xml is certainly an XML document: Select the root node of the document
    node = xml.root

    # merge any namespaces found on the xml node into the namespace hash
    namespaces = namespaces.merge(xml.collect_namespaces)

    # if the node name is equal to the tag name then the we are parsing the
    # root element and that is important to record so that we can apply
    # the correct xpath on the elements of this document.

    root = node.name == tag_name
  end

  # If the :single option has been specified or we are at the root element
  # then we are going to return a single element or nil if no nodes are found
  single = root || options[:single]

  # if a namespace has been provided then set the current namespace to it
  # or use the namespace provided by the class
  # or use the 'xmlns' namespace if defined

  namespace = options[:namespace] || self.namespace || namespaces.key?('xmlns') && 'xmlns'

  # from the options grab any nodes present and if none are present then
  # perform the following to find the nodes for the given class

  nodes = options.fetch(:nodes) do
    find_nodes_to_parse(options, namespace, tag_name, namespaces, node, root)
  end

  # Nothing matching found, we can go ahead and return
  return (single ? nil : []) if nodes.empty?

  # If the :limit option has been specified then we are going to slice
  # our node results by that amount to allow us the ability to deal with
  # a large result set of data.

  limit = options[:in_groups_of] || nodes.size

  # If the limit of 0 has been specified then the user obviously wants
  # none of the nodes that we are serving within this batch of nodes.

  return [] if limit == 0

  collection = []

  nodes.each_slice(limit) do |slice|
    part = slice.map do |n|
      parse_node(n, options, namespace, namespaces)
    end

    # If a block has been provided and the user has requested that the objects
    # be handled in groups then we should yield the slice of the objects to them
    # otherwise continue to lump them together

    if block_given? && options[:in_groups_of]
      yield part
    else
      collection += part
    end
  end

  # If we're parsing a single element then we are going to return the first
  # item in the collection. Otherwise the return response is going to be an
  # entire array of items.

  if single
    collection.first
  else
    collection
  end
end

#register_namespace(name, href) ⇒ Object

Register a namespace that is used to persist the object namespace back to XML.

Examples:


register_namespace 'prefix', 'http://www.unicornland.com/prefix'

# the output will contain the namespace defined

"<outputXML xmlns:prefix="http://www.unicornland.com/prefix">
...
</outputXML>"

Parameters:

  • name (String)

    the xml prefix

  • href (String)

    url for the xml namespace


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# File 'lib/happymapper.rb', line 90

def register_namespace(name, href)
  @registered_namespaces.merge!(name => href)
end

#tag(new_tag_name) ⇒ Object

Parameters:

  • new_tag_name (String)

    the name for the tag


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# File 'lib/happymapper.rb', line 221

def tag(new_tag_name)
  @tag_name = new_tag_name.to_s unless new_tag_name.nil? || new_tag_name.to_s.empty?
end

#tag_nameString

The name of the tag

Returns:

  • (String)

    the name of the tag as a string, downcased


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# File 'lib/happymapper.rb', line 230

def tag_name
  @tag_name ||= name && name.to_s.split('::')[-1].downcase
end

#with_nokogiri_config(&blk) ⇒ Object

Register a config callback according to the block Nokogori expects when calling Nokogiri::XML::Document.parse().

See nokogiri.org/Nokogiri/XML/Document.html#method-c-parse

Parameters:

  • the (Proc)

    proc to pass to Nokogiri to setup parse options


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# File 'lib/happymapper.rb', line 280

def with_nokogiri_config(&blk)
  @nokogiri_config_callback = blk
end

#wrap(name, &blk) ⇒ Object

There is an XML tag that needs to be known for parsing and should be generated during a to_xml. But it doesn't need to be a class and the contained elements should be made available on the parent class

Parameters:

  • name (String)

    the name of the element that is just a place holder

  • blk (Proc)

    the element definitions inside the place holder tag


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# File 'lib/happymapper.rb', line 241

def wrap(name, &blk)
  # Get an anonymous HappyMapper that has 'name' as its tag and defined
  # in '&blk'.  Then save that to a class instance variable for later use
  wrapper = AnonymousWrapperClassFactory.get(name, &blk)
  wrapper_key = wrapper.inspect
  @wrapper_anonymous_classes[wrapper_key] = wrapper

  # Create getter/setter for each element and attribute defined on the anonymous HappyMapper
  # onto this class. They get/set the value by passing thru to the anonymous class.
  passthrus = wrapper.attributes + wrapper.elements
  passthrus.each do |item|
    class_eval <<-RUBY, __FILE__, __LINE__ + 1
      def #{item.method_name}
        @#{name} ||= self.class.instance_variable_get('@wrapper_anonymous_classes')['#{wrapper_key}'].new
        @#{name}.#{item.method_name}
      end
      def #{item.method_name}=(value)
        @#{name} ||= self.class.instance_variable_get('@wrapper_anonymous_classes')['#{wrapper_key}'].new
        @#{name}.#{item.method_name} = value
      end
    RUBY
  end

  has_one name, wrapper
end