nokogiri

###
240 # Create a builder with an existing root object. This is for use when
241 # you have an existing document that you would like to augment with
242 # builder methods. The builder context created will start with the
243 # given +root+ node.
244 #
245 # For example:
246 #
247 # doc = Nokogiri::XML(open('somedoc.xml'))
248 # Nokogiri::XML::Builder.with(doc.at('some_tag')) do |xml|
249 # # ... Use normal builder methods here ...
250 # xml.awesome # add the "awesome" tag below "some_tag"
251 # end
252 #
253 def self.with root, &block
254 new({}, root, &block)
255 end
256
257 ###
258 # Create a new Builder object. +options+ are sent to the top level
259 # Document that is being built.
260 #
261 # Building a document with a particular encoding for example:
262 #
263 # Nokogiri::XML::Builder.new(:encoding => 'UTF-8') do |xml|
264 # ...
265 # end
266 def initialize options = {}, root = nil, &block
267
268 if root
269 @doc = root.document
270 @parent = root
271 else
272 namespace = self.class.name.split('::')
273 namespace[-1] = 'Document'
274 @doc = eval(namespace.join('::')).new
275 @parent = @doc
276 end
277
278 @context = nil
279 @arity = nil
280 @ns = nil
281
282 options.each do |k,v|
283 @doc.send(:"#{k}=", v)
284 end
285
286 return unless block_given?
287
288 @arity = block.arity
289 if @arity <= 0
290 @context = eval('self', block.binding)
291 instance_eval(&block)
292 else
293 yield self
294 end
295
296 @parent = @doc
297 end