Simon Kröger
3/13/2006 9:16:00 PM
Hi Miles,
interesting idea, i did a quick (proof of concept) hack:
-------------------------------------------------------------
class Xmltree
attr_accessor :childs
attr_accessor :content
attr_accessor :attributes
def initialize
self.childs = []
self.attributes = {};
end
def method_missing meth, *args, &block
return attributes[args[0]] = args[1] if meth == :[]=
return attributes[args[0]] if meth == :[]
return self.content = args if meth == '='.intern
unless child = childs.assoc(meth.to_s.chomp('='))
childs << child = [meth.to_s.chomp('='), Xmltree.new]
end
return child[1] if meth.to_s[-1] != ?=
child[1].content = args
end
def to_s
childs.map do |t, c|
"""<#{t} #{c.attributes.map do |a, v|
"#{a}=\"#{v}\""
end.join(' ')}>\n#{c}</#{t}>\n"""
end.join + content.to_s + (content ? "\n" : '')
end
end
-------------------------------------------------------------
usage:
-------------------------------------------------------------
xml = Xmltree.new
xml.header.title = 'this is a demo'
xml.body.component['type'] = 'the answer'
xml.body.component = 42
puts xml
-------------------------------------------------------------
output:
-------------------------------------------------------------
<header >
<title >
this is a demo
</title>
</header>
<body >
<component type="the answer">
42
</component>
</body>
-------------------------------------------------------------
cheers
Simon
Miles Monroe:
> I would like to use Ruby and REXML to wrap an XML document and allow
> access to the element nodes, attributes, and text. Essentially I need
> an XML document builder loosely coupled from the document.
>
> It seems like Ruby is powerful enough to code generate a class given an
> XML document or build an object at run-time with the appropriate
> accessors.
>
> For instance:
>
> order = XmlBuilder.new
>
> order.add("root").add("header")
> order.root.add("body")
>
> order.body.add("component").attributes["type"] = "metric"
>
> order.write($stdout)
>
> I'd also like to be able to plug-in input validation when assigning
> values to elements and attributes.
>
> Has anyone done this before?
>
> Thanks.
>