Ruby on Rails XML generation

Question

I am attempting to build a simple method that creates an XML file from a database in ruby on rails. I feel like my code is right but I am not seeing all of the users in the XML.
I am a complete newbie to RoR.

Here's my code:

def create_file  
  @users = User.find(:all)
  file = File.new('dir.xml','w')
  doc = Document.new

  make = Element.new "make"
  @users.each do |y|
    make.add_element "name"
    make.elements["name"].text  = y.name
    make.add_element "description"
    make.elements["description"].text = y.description
  end    

  doc.add_element make

  file.puts doc
  file.close
end

And my XML output:

<make>
 <name>sammy</name><description>samsdescription</description>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
 <name/><description/>
</make>

I don't get why all the fields aren't populated. Why is just one of the database entires showing up? I really appreciate the help.

Answer 1

There's a bug in your code. In each iteration you create an element with add_element and then try to access that element with Elements#[]. But when you use a node name in Elements#[] it returns only the first matching node. So you are creating a node in every iteration but updating only the first one. Try to change the code to the following:

@users.each do |y|
  name_node = make.add_element "name"
  name_node.text  = y.name
  desc_node = make.add_element "description"
  desc_node.text = y.description
end

By the way, your XML structure is a bit strange. Wouldn't it be more clear if you wrapped every name/description pair inside another node (say, user) and then have many user nodes?

Answer 2

You ought to investigate @users.to_xml to see if it is something you could use instead of rolling your own solution. Read more about it in the Rails API docs.