class RSolr::Xml::Generator

if the doc had a "nickname" field with the value of "Tim".
The "nickname" field would have a boost="20.0"
Each doc element would have a boost="10.0".
and a commitWithin="1.0".
would result in an add element having the attributes boost="10.0"

end
nickname.attrs[:boost] = 20 if nickname.value=='Tim' # boost a field
nickname = doc_msg.field_by_name(:nickname)
doc_msg.attrs[:boost] = 10.00 # boost the document
solr.add({:id=>1, :nickname=>'Tim'}, {:boost=>5.0, :commitWithin=>1.0}) do |doc_msg|

For example:

You can set xml element attributes for each "doc" element or individual "field" elements.
The value yielded to the block is a Message::Document; for each solr doc in "data".
This method can also accept a block.

"add_attrs" can be a hash for setting the add xml element attributes.

If a value is an array, multiple fields will be created.
- each hash should be a simple key=>value pair representing a solr doc.
"data" can be a hash or an array of hashes.
generates "add" xml for updating solr

def add data, add_attrs = nil, &block
  add_attrs ||= {}
  data = RSolr::Array.wrap(data)
  build do |xml|
    xml.add(add_attrs) do |add_node|
      data.each do |doc|
        doc = RSolr::Document.new(doc) if doc.respond_to?(:each_pair)
        yield doc if block_given?
        doc_node_builder = to_xml(doc)
        self.class.use_nokogiri ? add_node.doc_(doc.attrs,&doc_node_builder) : add_node.doc(doc.attrs,&doc_node_builder)
      end
    end
  end
end