Nokogiri: How can I add a child to a node at a specific position?

Question

Hello all,

I have a node which has two children: an XML text and an XML element.

<h1 id="Installation-blahblah">Installation on server<a href="#Installation-blah" class="wiki-anchor">&para;</a>

In this case the XML text is:

Installation on server

and the XML element:

   <a href="#Installation-blah" class="wiki-anchor">anchor;</a>

I then create a node like this:

span_node = Nokogiri::XML::Node.new('span',doc)
span_node['class'] = 'edit-section'

link_node = Nokogiri::XML::Node.new('a',doc)
link_node['href'] = "/wiki/#{page_id}/#{@page.title}/edit?section=#{section_index}"
link_node['class'] = 'icon icon-edit'
link_node.content = 'mylink'

span_node.add_child(link_node)

Now to add the above node to the main node we can use the following:

node.add_child(span_node)

This appends the span node at the end. How can I put the span_node in front of all children?

Answer 1

You can use NodeSet#before like this:

node.children.before(span_node)

NodeSet#before is a short-cut method to insert an item as the first element. A more general-purpose solution is to use Node#before and Node#after. For example, some_node.before foo will add the node foo as the sibling directly before some_node. Node#after is similar. Note that this:

node.children.first.before(span_node)

is thus equivalent to the solution above.

Answer 2

Thanks Pesto for your almost correct solution.

The working solution is:

node.children.first.add_previous_sibling(span_node)