Creates a new Ruby object from XML using mapping information annotated in the class.

The input data is either an XML::Node or a String representing the XML document.

Example

 book = Book.parse(File.read("book.xml"))

or

 book = Book.parse("<book><name>Beyond Java</name></book>")

See also: xml_construct

Returns the tag name (also known as xml_name) of the class. If no tag name is set with xml_name method, returns default class name in lowercase.

Returns array of internal reference objects, such as attributes and composed XML objects

Declares an accesser to a certain xml element, whether an attribute, a node, or a typed collection of nodes

sym

Symbol representing the name of the accessor

Type options

All type arguments may be used as the type argument to indicate just type, or used as :from, pointing to a xml name to indicate both type and attribute name. Also, any type may be passed via an array to indicate that multiple instances of the object should be returned as an array.

:attr

Declare an accessor that represents an XML attribute.

Example:

 class Book
  xml_reader :isbn, :attr => "ISBN" # 'ISBN' is used to specify :from
  xml_accessor :title, :attr        # :from defaults to :title
 end

To map:

 <book ISBN="0974514055" title="Programming Ruby: the pragmatic programmers' guide" />

:text

The default type, if none is specified. Declares an accessor that represents a text node from XML.

Example:

 class Book
   xml :author, false, :text => 'Author'
   xml_accessor :description, :text, :as => :cdata
   xml_reader :title
 end

To map:

 <book>
  <title>Programming Ruby: the pragmatic programmers' guide</title>
  <description><![CDATA[Probably the best Ruby book out there]]></description>
  <Author>David Thomas</author>
 </book>

Likewise, a number of :text node values can be collected in an array like so:

Example:

 class Library
   xml_reader :books, [:text], :in => 'books'
 end

To map:

 <library>
   <books>
     <book>To kill a mockingbird</book>
     <book>House of Leaves</book>
     <book>Gödel, Escher, Bach</book>
   </books>
 </library>

:content

A special case of :text, this refers to the content of the current node, rather than a sub-node

Example:

 class Contributor
   xml_reader :name, :content
   xml_reader :role, :attr
 end

To map:

 <contributor role="editor">James Wick</contributor>

Hash

Somewhere between the simplicity of a :text/:attr mapping, and the complexity of a full Object/Type mapping, lies the Hash mapping. It serves in the case where you have a collection of key-value pairs represented in your xml. You create a hash declaration by passing a hash mapping as the type argument. A few examples:

Hash of :attrs

For xml such as this:

   <dictionary>
     <definitions>
       <definition dt="quaquaversally"
                   dd="adjective: (of a geological formation) sloping downward from the center in all directions." />
       <definition dt="tergiversate"
                   dd="To use evasions or ambiguities; equivocate." />
     </definitions>
   </dictionary>

You can use the :attrs key in you has with a [:key, :value] name array:

   xml_reader :definitions, {:attrs => ['dt', 'dd']}, :in => :definitions

Hash of :texts

For xml such as this:

   <dictionary>
     <definition>
       <word/>
       <meaning/>
     </definition>
     <definition>
       <word/>
       <meaning/>
     </definition>
   </dictionary>

You can individually declare your key and value names:

   xml_reader :definitions, {:key => 'word',
                             :value => 'meaning'}

Hash of :content &c.

For xml such as this:

   <dictionary>
     <definition word="quaquaversally">adjective: (of a geological formation) sloping downward from the center in all directions.</definition>
     <definition word="tergiversate">To use evasions or ambiguities; equivocate.</definition>
   </dictionary>

You can individually declare the key and value, but with the attr, you need to provide both the type and name of that type (i.e. {:attr => :word}), because omitting the type will result in ROXML defaulting to :text

   xml_reader :definitions, {:key => {:attr => 'word'},
                             :value => :content}

Hash of :name &c.

For xml such as this:

   <dictionary>
     <quaquaversally>adjective: (of a geological formation) sloping downward from the center in all directions.</quaquaversally>
     <tergiversate>To use evasions or ambiguities; equivocate.</tergiversate>
   </dictionary>

You can pick up the node names (e.g. quaquaversally) using the :name keyword:

   xml_reader :definitions, {:key => :name,
                             :value => :content}

Other ROXML Class

Declares an accessor that represents another ROXML class as child XML element (one-to-one or composition) or array of child elements (one-to-many or aggregation) of this type. Default is one-to-one. Use :array option for one-to-many, or simply pass the class in an array.

Composition example:

 <book>
  <publisher>
    <name>Pragmatic Bookshelf</name>
  </publisher>
 </book>

Can be mapped using the following code:

  class Book
    xml_reader :publisher, Publisher
  end

Aggregation example:

 <library>
  <books>
   <book/>
   <book/>
  </books>
 </library>

Can be mapped using the following code:

 class Library
   xml_reader :books, [Book], :in => "books"
 end

If you don‘t have the <books> tag to wrap around the list of <book> tags:

 <library>
  <name>Ruby books</name>
  <book/>
  <book/>
 </library>

You can skip the wrapper argument:

   xml_reader :books, [Book]

Blocks

For readonly attributes, you may pass a block which manipulates the associated parsed value.

 class Muffins
   include ROXML

   xml_reader :count, :from => 'bakers_dozens' {|val| val.to_i * 13 }
 end

For hash types, the block recieves the key and value as arguments, and they should be returned as an array of [key, value]

Other options

:from

The name by which the xml value will be found, either an attribute or tag name in XML. Default is sym, or the singular form of sym, in the case of arrays and hashes.

:as

:cdata for character data

:in

An optional name of a wrapping tag for this XML accessor

:else

Default value for attribute, if missing

Declares a writable xml reference. See xml for details.

On parse, call the target object‘s initialize function with the listed arguments

Sets the name of the XML element that represents this class. Use this to override the default lowercase class name.

Example:

 class BookWithPublisher
  xml_name :book
 end

Without the xml_name annotation, the XML mapped tag would have been "bookwithpublisher".

Declares a read-only xml reference. See xml for details.